Information
-
Patent Grant
-
6439344
-
Patent Number
6,439,344
-
Date Filed
Friday, January 26, 200124 years ago
-
Date Issued
Tuesday, August 27, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Stodola; Daniel P.
- Thompson; Hugh B.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 182 113
- 182 45
- 182 3
- 052 1254
- 052 1272
- 052 1271
- 052 7361
- 248 22924
- 248 22925
- 248 2285
- 248 2286
- 256 DIG 6
- 256 DIG 5
- 256 32
- 256 65
- 256 67
- 256 59
-
International Classifications
-
Abstract
Safety stanchions for supporting a safety cable and the like include a tapered tubular post having a lower end for attachment to a support base at an oblique angle and an upper end for supporting the safety cable. A unique base or base assembly for mounting a stanchion upon a structural member such as an I beam is also provided. Various unique safety stanchion apparatus and methods for mounting safety stanchions to concrete floors, beams and girders and other concrete structures are also provided.
Description
TECHNICAL FIELD
The present invention relates generally to products and methods for providing fall protection systems for construction workers, maintenance workers, and others who work or walk upon elevated structures. More particularly, it relates to fall protection systems which employ safety stanchions mounted to the elevated structure so as to anchor and support safety cables.
BACKGROUND OF THE INVENTION
During the construction of a bridge, building or other structure, it is common for workers to work and walk upon structural or architectural steel beams forming a part of the construction. Obviously, it is important but difficult to protect such workers and others from harm when they inadvertently slip and fall from elevated beams.
It is also important, for the purpose of controlling construction costs and facilitating rapid construction, that any fall protection system which is put in place to protect the workers be relatively inexpensive, relatively quick and easy to install, and later dismount, and cause little interference with the construction process itself.
Most conventional fall protection systems to which the present invention relates involve systems for supporting the worker with a safety cable that may be anchored and supported in various ways. Once a safety cable is anchored and supported, workers may obtain support by attaching themselves to the safety cable, as, for example, by way of a safety lanyard attached both to the cable and to a harness worn by the worker.
Unfortunately, in most superstructures where persons are called upon to walk and work upon elevated beams, there are few or no suitable anchoring points for attaching safety cables. Attaching the cables directly to the beams beneath the workers' feet could increase the likelihood of tripping, and could also increase the potential fall distance.
Even if there are elevated anchoring points in the superstructure, the location of those points could cause the safety cable to extend directly above the very beam upon which the worker wishes to walk and work, thereby hindering the worker's actions. In comparison to such anchoring points, it would be preferable, instead, to anchor a safety cable in such a way that, as the safety cable extends along the beam, it is suspended not just above the beam but also off-set slightly to one side of the beam, so that it will not unnecessarily hinder the worker as he or she works upon or walks along the beam's upper surface.
A means of providing fall protection with such an elevated but off-set cable positioning is disclosed in U.S. Pat. No. 5,307,897, wherein a safety stanchion employs both a first and a second lock means, with the first lock means depending upon properly torqued bolts (which could be subject to failure from loss of friction if worn or insufficiently tightened), and with the second lock means being mounted to a post and being somewhat complex, comprising, for example, a ratchet lock mechanism comprising a strap made of nylon or another synthetic material (which sunlight, chemicals or a nearby heat source, such as nearby welding, could render subject to failure). That previously disclosed safety stanchion is preferably used with a safety cable having an in-line shock absorber.
U.S. Pat. No. 6,173,809 (the '809 patent) which discloses an invention of which I am a co-inventor also provides a safety stanchion with an elevated and preferably off-set cable positioning. However, it does so with various other means, none of which, for example, require a ratchet lock mechanism or a nylon or synthetic strap as shown in the aforementioned art. The invention of the '809 patent also provides a safety stanchion having a post that preferably can, by flexing and by permanently deforming without failing, reduce and absorb at least some of the shock and sudden loading caused by a worker's fall from a beam, without the need for a safety cable having an in-line shock absorber.
As previously noted, there are advantages to be gained by providing a fall protection system that is relatively inexpensive, that may be quickly and easily mounted to and dismounted from an elevated beam, and that will support and anchor a safety cable above and slightly to the side of the elevated beam. The invention of the '809 patent teaches such a safety stanchion.
One embodiment of the invention of the '809 patent provides a safety stanchion for mounting upon a surface such as structural I or H shaped beam which are typically found in the superstructure of a bridge, a building or some other structure being built.
This safety stanchion includes a tapered tubular post having a lower end for attachment to a support base at preferably an oblique angle and an upper end for supporting a safety cable and the like. Due to its tapered shape, the post's upper end has an outside diameter which is less than that of its lower end. The post also preferably has a wall thickness of less than 0.125 inches and is frustoconically shaped. In addition, the post is preferably made out of an energy absorbing, elastic-like, high strength steel such as A595 grade steel which in cooperation with the post's wall thickness and tapered, preferably frustoconical, shape is believed to render the post capable of inelastically deforming before it fails, thereby better able to break a worker's fall without actually breaking in half. Fail or failure of the post as used herein refers to a post which has actually broken or buckled to a point where it is no longer capable of providing any significant resistant to lateral forces or other forces tending to cause bowing of the post.
As will be appreciated, the attachment of the post's lower end to its base at an oblique angle enables the suspension of safety cables above, but slightly to the side, of the particular beam or surface upon which the safety stanchion is mounted.
The stanchion also preferably includes a cap, having two bores, which is firmly secured to the upper terminus of the post, and by means of which safety cables can be easily attached to the tapered tubular post, and therefore to the safety stanchion itself, such as with simple, conventional devises.
In the preferred safety stanchion of this type, the tapered post is capable of flexing and permanently (or inelastically) deforming without failing, in response to sudden loads (within its design limits) that might occur when a person who is attached to the stanchion via a conventional safety cable falls from an elevated beam or similar surface upon which the stanchion is mounted.
The invention of the '809 patent also provides a unique base or base assembly for mounting a stanchion upon a structural member such as an I beam, H beam or other structural member having flange portions, regardless of the structural member's orientation to the horizon, i.e. vertical, horizontal or other disposition. In its broadest sense, the base has a mounting assembly or means which includes first jaw means for engaging a first portion of a structural beam and opposing second jaw means for engaging a second portion of the beam. The mounting assembly also includes right and left rod assemblies which respectively cooperate with the first and second jaw means for drawing the jaw means together to clamp a beam, typically the flange portions of a structural beam which extend outwardly from the center section of a typical structural I or H beam. The rod assemblies are preferably oriented with respect to each other so that their longitudinal axes converge towards each other. A preferred angle of convergence may extend up to 90 degrees as measured by the included angle defined by the longitudinal axes of the rod assemblies.
As used herein, converge means to draw closer to or approach each other and such converging, non-parallel positioning of the rods enables better clamping of the beam. Specifically, the converging rods are believed to be better able to resist both twisting and longitudinal motion along the beam (sometimes called “walking”), in response to vibration, twisting or other forces during the arrest of a worker's fall.
In a preferred embodiment of the invention of the '809 patent, the rod of each rod assembly is provided with aggressive threads on the order of 3 to 7.5 threads per inch for cooperating with complementary threaded first and second internally threaded members which in turn respectively cooperate with the first and second jaw means of the mounting assembly to clamp a structural beam when one of the internally threaded members, preferably a wing nut, is tightened by threading it in a direction which causes the jaw means to draw together and clamp a beam disposed between the jaw means. The aggressive threads enable a workman to install the stanchion on a beam very quickly since they cause the jaw means to close and thereby clamp a beam disposed between the jaw means with only a few turns of one of the internally threaded members.
Another safety stanchion of the invention of the '809 patent for mounting on a structural beam and the like has a sleeve on the stanchion's base for slidably receiving an end of the stanchion's post. Fastening means such as set screw type bolts are also provided for securing the post's end in the sleeve when it is slidably received therein. The sleeve may be integral with the base or rigidly affixed to the base for example by welding it to the base. The sleeve may also be positioned or oriented on the base so that the base may be mounted upon either vertically disposed I beams, i.e. columns, or horizontally disposed I beams. A typical post used in conjunction with this base is L-shaped and as shown in the drawings the lower end of the L-shaped post is slidably received in the sleeve.
In addition and as will be appreciated, all safety stanchions of the invention of the '809 patent provide an effective fall protection system, which is lightweight, simple, relatively unaffected by sunlight, chemicals and indirect heating, relatively quick and easy to mount upon a beam by hand or with a simple tool, capable of supporting and anchoring safety cables above but to the side of the mounted beam, where they will not unnecessarily hinder a worker on the beam, inherently able to reduce and absorb, through flexion and through permanent deformation, some of the shock and sudden load caused by a worker's fall from the beam, and better able to resist twisting and longitudinal motion upon the beam.
While the invention of the '809 patent is easily attachable to I beams and other structural members, a need still exists for a safety stanchion which is directly and easily attachable to a concrete structure. In addition, a need exists for apparatus and methods for attaching existing I beam mounted safety stanchions to concrete.
DISCLOSURE OF THE INVENTION
The present invention builds upon the invention of the '809 patent and the prior art by providing a unique safety stanchion for mounting directly to concrete. The unique stanchion includes a post having first and second ends, means for supporting a safety cable at said first end of said post and a base attached to the second end of the post for mounting the post on a flat surface of a concrete structure. The base includes a mounting plate having a generally flat bottom surface for placement against the flat surface of the concrete structure as well as a top surface and a plurality of holes extending through the plate from the bottom surface to the top surface.
In addition, the present invention provides several apparatus and methods for mounting any type of safety stanchion to concrete including the stanchions of the '809 patent, the prior art and the unique safety stanchion of the present invention for being mounted directly to concrete.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate and provide views of a preferred embodiment of the invention of the '809 patent which is incorporated herein by reference as well as the present invention. Other features, objects and advantages of the present invention as well as the invention of the '809 patent will appear in and be apparent from the following detailed description, when reference is made to the accompanying drawings.
In the accompanying drawings:
FIG. 1
is a side elevational view, partly in phantom, of a safety stanchion of the invention of the '809 patent, mounted to a structural I-beam illustrated in section. The phantom view shows the stanchion in a bowed position which is a position it will assume when subjected to forces causing it to bow as shown.
FIG. 2
is a cross-sectional view of the safety stanchion of
FIG. 1
taken along lines
2
—
2
thereof.
FIG. 3
is a partial, broken away, front elevational view, partly in phantom, of the safety stanchion of FIG.
1
. Again, the phantom view shows the stanchion in a bowed position which is a position it will assume when subjected to forces casing it to bow as shown.
FIG. 4
is a side elevational view of an alternative flange hook assembly which may be used in the safety stanchion of FIG.
1
.
FIG. 5
is a partial front elevational view of the safety stanchion of
FIG. 1
, shown complete except for the omission of the right wing nut and the right quick-thread rod (which were omitted to provide an unobstructed view of the first right rod receiver);
FIG. 5
further illustrates a portion (broken away) of a fall protection system provided by the invention of the '809 patent, and further illustrates an I-beam (broken away).
FIG. 6
is a cross-sectional view of the safety stanchion of
FIG. 5
taken along lines
6
—
6
of FIG.
5
.
FIG. 7
is a cross-sectional view of another safety stanchion of the invention of the '809 patent taken along lines
7
—
7
of FIG.
8
.
FIG. 8
is a front side elevational view of another safety stanchion of the invention of the '809 patent which is mounted to a structural I-beam column illustrated in section.
FIG. 9
is a rear side elevational view of the safety stanchion of FIG.
8
.
FIG. 10
is perspective view of an embodiment of the present invention for direct mounting of a safety stanchion to a concrete structure.
FIG. 11
is a partially broken away perspective view of an embed of the present invention for mounting a safety stanchion to a concrete structure.
FIG. 12
is a cross-sectional view taken along lines
12
—
12
of FIG.
11
.
FIG. 13
is a perspective view of a mounting adaptor of the present invention for mounting a safety stanchion to a concrete structure.
FIG. 14
is a cross-sectional view taken along lines
14
—
14
of FIG.
13
. The bolts
226
of this embodiment for anchoring a safety stanchion in a concrete structure are also shown in FIG.
10
.
FIG. 15
is a perspective view of another embed of the present invention for mounting a safety stanchion to a concrete structure.
FIG. 16
is a cross-sectional view taken along lines
16
—
16
of FIG.
15
.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1-3
,
5
&
6
illustrate a flexible and deformable safety stanchion
10
of the invention of the '809 patent, mounted upon an I-beam
12
.
As illustrated in
FIG. 5
, safety stanchion
10
serves as a support for suspending two conventional safety cables
14
a
and
14
b
, each of which is preferably supported at its other end by another safety stanchion
10
(not shown). The safety cables
14
a
,
14
b
are provided with looped ends
16
a
,
16
b
and are respectively anchored to the safety stanchion
10
by means of conventional devises
18
a
,
18
b
that are respectively fitted with clevis pins
20
a
,
20
b.
Clevises
18
a
and
18
b
are passed, respectively, through the looped ends
16
a
and
16
b.
The devises
18
a
and
18
b
are both then pinned to a cap
22
at the top of the safety stanchion
10
, by the passage of their respective clevis pins
20
a
and
20
b
through the two bores
24
a
and
24
b
(illustrated in
FIG. 3
) that are provided in the cap
22
, with clevis pin
20
a
passing through bore
24
a
and clevis pin
20
b
passing through bore
24
b.
Other forms of cap would be possible, as would other methods of attaching a safety cable to the cap. For example, when a safety stanchion
10
is used at an intermediate position in an extended line of safety stanchions
10
a different form of cap could (but need not) be used, such as a pass-through type cap like that taught by U.S. Pat. No. 4,037,824.
As illustrated in
FIG. 5
, safety cable
14
b
supports a conventional lanyard
26
(shown broken away), which is clipped and thereby slidingly attached to the safety cable
14
b
. As known to those familiar with the art, the lanyard
26
connects with a belt or harness (not shown) that is worn by a worker present on the superstructure of a building, a bridge, or some other structure. A preferred lanyard for use in accordance with the present invention is of the shock absorbing type.
It should be noted that it is not necessary to attach two separate safety cables to the safety stanchion
10
, and for some of its applications (i.e. when supporting a single cable or when used as an end point) it would need to support only a single cable connected to only one adjacent stanchion. Therefore, either safety cable
14
a
or safety cable
14
b
could be omitted without preventing the safety stanchion
10
from providing useful support to a worker clipped to whichever safety cable remained.
Furthermore, for some applications of the safety stanchion
10
(e.g. when the safety stanchion is used at an intersection of intersecting beams for which safety cables are provided) a safety cable could extend and be supported horizontally but perpendicularly to the safety cables
14
a
,
14
b
shown in FIG.
5
. In such an application, the perpendicular safety cable could be attached to the cap
22
of the safety stanchion
10
, or could instead be joined (either fixedly or slidingly) at one end to a point on one of the safety cables
14
a
or
14
b;
at the other end, the perpendicular safety cable could be joined to the cap
22
of another safety stanchion, or could instead be joined (either fixedly or slidingly) to another safety cable, supported by other safety stanchions
10
, that is separate from but parallel to the joined safety cable
14
a
or
14
b.
So that it may provide useful support, the safety stanchion
10
is mounted upon an I-beam
12
, a typical example of which is illustrated in
FIGS. 1 and 5
. The typical I-beam
12
has an upper flange
28
, a lower flange
30
, and a medial support panel
32
(which may be solid, as shown, or instead include truss components). As best illustrated in
FIG. 1
, the safety stanchion
10
is preferably mounted upon the upper flange
28
of an I-beam
12
.
The safety stanchion
10
may alternatively be flange mounted, in an equivalent manner, upon an H-beam (not shown) or a steel joist or other flanged structural member; therefore, as used herein the term “I-beam” may refer generally to an I-beam
12
, an H-beam or a steel joist or other flanged structural member of sufficient strength. Furthermore, for some applications the safety stanchion
10
(or other derivations thereof) may be inverted and mounted to the lower flange
30
of the I-beam
12
or other overhead flanged structural member of sufficient strength, so as to suspend the safety stanchion below the I-beam
12
or other member.
FIGS. 1 and 5
illustrate that the safety stanchion
10
includes a base or base assembly
34
, a straight but tapered tubular post
36
and previously mentioned cap
22
.
The base assembly
34
includes a channel member
35
, comprising an upper portion
38
, a vertical portion
40
, a lower portion
42
, a vertical lip
46
, and two equivalent threaded hexagonal nuts
44
a
and
44
b
that are rigidly attached, preferably welded, to lower portion
42
and that are aligned with two bores
45
(only one of which is shown) provided in lower portion
42
for receiving bolts
48
a
,
48
b.
The upper portion
38
, vertical portion
40
and lower portion
42
of the channel member
35
are preferably constructed in one piece from a single plate or other piece of steel, cut and bent or otherwise formed to include them and as such comprise a member referred to herein and in the claims appended hereto as the first jaw means. As illustrated in
FIG. 1
, this first jaw means or channel member
35
engages a first portion, specifically a first or right flange portion of the upper flange
28
of the illustrated I-beam
12
. As also illustrated, the upper portion
38
is bent at right angles to the vertical portion
40
, which in turn is bent at right angles to the lower portion
42
. By means of the upper portion
38
, vertical portion
40
and lower portion
42
of its channel member
35
, the base assembly
34
defines an open channel for receiving the right side (as viewed in
FIG. 1
) of upper flange
28
of I-beam
12
. As best illustrated in
FIG. 1
, when the safety stanchion
10
is mounted upon the upper flange
28
of a horizontal I-beam
12
, the underside of the upper portion
38
of the channel member
35
rests horizontally upon and above the upper flange
28
, and the lower portion
42
of the channel member
35
is suspended below the upper flange
28
(but above the lower flange
30
) by the vertical portion
40
of the channel member
35
. As so suspended, the lower portion
42
of the channel member
35
, except for its vertical lip
46
, is approximately perpendicular to the vertical portion
40
of the channel member
35
.
As shown in
FIG. 1
, it is preferable that the lower portion
42
of the channel member
35
be dimensioned so that it does not extend as far from the vertical portion
40
as does the upper portion
38
, so that even when the safety stanchion
10
is mounted upon smaller beams the lower portion
42
will not engage the medial support panel
32
of the I-beam
12
, and will therefore avoid interference with the mounting. Referring to
FIG. 5
, bolts
48
a
and
48
b
are threaded, respectively, into and completely through the two threaded hexagonal nuts
44
a
and
44
b
, starting from below the lower portion
42
of the channel member
35
, so that each of the bolts
48
a
and
48
b
is threaded into the channel member
35
.
When the safety stanchion
10
is securely mounted upon the upper flange
28
of a horizontal I-beam
12
, the two bolts
48
a
and
48
b
(also referred to herein in the claims appended hereto as the jaw opening adjustment means) are tightened until they contact the underside of the upper flange
28
of the I-beam
12
.
As illustrated in
FIG. 5
, the base assembly
34
also includes a left rod receiver
50
and a right rod receiver
52
of equivalent size and shape, each of which is preferably constructed from a length of steel pipe. Also as illustrated in
FIG. 5
, the left rod receiver
50
and the right rod receiver
52
both rest upon and are both longitudinally supported by the upper portion
38
of the channel member
35
, to which both are welded and therefore secured firmly in position.
However, in that position the left rod receiver
50
and the right rod receiver
52
also partially extend slightly beyond (and, as viewed in
FIG. 1
, to the right of) the upper front edge
54
of the upper portion
38
of the channel member
35
, so that the portions of those rod receivers
50
and
52
that so extend do not rest upon the upper portion
38
. The purpose for this slight extension is to provide clearance between the vertical portion
40
of the channel member
35
and both the left wing nut
56
and the right wing nut (not shown) when those wing nuts are positioned, respectively, against the left rod receiver
50
and the right rod receiver
52
.
The longitudinal axis of the left rod receiver
50
and the longitudinal axis of the right rod receiver
52
are located in the same plane, hereinafter called the “axis plane,” but they are not parallel. Instead, as best illustrated in
FIG. 6
, those longitudinal axes tend to converge as the left rod receiver
50
and the right rod receiver
52
extend along and across the upper portion
38
of the channel member
35
by moving away from the upper front edge
54
of that upper portion
38
.
Angle A (as illustrated in
FIG. 6
) from the longitudinal axis of the right rod receiver
52
to a line that is parallel to and directly above the upper right edge
60
of the upper portion
38
of the channel member
35
(but that is drawn in the axis plane as previously defined) is preferably ten (10) degrees clockwise, but may range from three (3) to forty five (45) degrees clockwise.
Similarly, the angle (not separately identified in
FIG. 6
) from the longitudinal axis of the left rod receiver
50
to a line that is parallel to and directly above the upper left edge
61
of that upper portion
38
(but that is drawn in the axis plane) is preferably ten (10) degrees counterclockwise, preferably, but may also range from three (3) to forty five (45) degrees counterclockwise. Accordingly, the “included angle” defined by the longitudinal axes of the left and right rod receivers
50
,
52
(which are also the longitudinal axes of the left and right rod assemblies as the terms are used in the claims appended hereto) is twice angle A and therefore is preferably about twenty (20) degrees. However, as indicated above it may range anywhere from six (6) to ninety (90) degrees. Generally, however, it is believed that best results are obtainable if the included angle is between ten (10) and thirty (30) degrees.
This converging, non-parallel positioning for the left and right rod receivers
50
,
52
is advantageous because it is believed to provide a more effective grip and to resist, more effectively, both twisting and longitudinal motion (or so-called “walking”) by the safety stanchion
10
relative to or along the longitudinal axis of the beam, in response to vibration, twisting or other forces during the arrest of a worker's fall.
The hollow interior of the left rod receiver
50
is not provided with threads; and neither is the hollow interior of the right rod receiver
52
.
The base assembly
34
also includes a left quick-thread rod
62
, and a right quick-thread rod (not shown) of equivalent size and shape, each of which has external threads along its entire length, and each of which is preferably constructed from a straight length of steel rod with aggressive threads of three (3) to seven and one-half (7½) pitch, i.e. 3 to 7½ threads per inch.
The base assembly
34
also includes a left flange hook assembly
64
, and a right flange hook assembly (not shown), both of which are more generically referred to herein in the claims appended hereto as the second jaw means. The left flange hook assembly
64
includes a rod receiver
66
. Likewise, the right flange hook assembly includes an equivalent rod receiver. The left flange hook assembly
64
also includes a flange hook portion
68
. Likewise, the right flange hook assembly also includes an equivalent flange hook portion.
The rod receiver
66
of the left flange hook assembly
64
is preferably constructed from a length of steel pipe (and so is the equivalent rod receiver of the right flange hook assembly). The flange hook portion
68
of the left flange hook assembly
64
is preferably cut or otherwise formed, approximately in an L-shape, from a single plate or other piece of steel (and so is the equivalent flange hook portion of the right flange hook assembly). The hollow interior of the rod receiver
66
of the left flange hook assembly
64
is not provided with threads (and neither is the hollow interior of the rod receiver of the right flange hook assembly).
As best illustrated in
FIG. 1
, the flange hook portion
68
of the left flange hook assembly
64
is welded to and depends from the underside of the rod receiver
66
of that assembly. The right flange hook assembly is equivalently assembled by welding its flange hook portion to the underside of its rod receiver.
The base assembly
34
also includes a threaded hexagonal left nut
70
and an equivalent threaded hexagonal right nut (not shown) which are broadly referred to in the claims appended hereto as the second internally threaded members. In addition, the left wing nut
56
and an equivalent right wing nut (not shown) are provided as previously mentioned which are broadly referred to in the claims appended hereto as the first internally threaded members. The threaded hexagonal left nut
70
and the left wing nut
56
are both provided with internal threads suitable for allowing them to be threadably mounted coaxially upon the left quick-thread rod
62
, so as to permit the left quick-thread rod to pass completely through, and to protrude from both sides of, their respective hollow, threaded interiors. Equivalently, the threaded hexagonal right nut and the right wing nut are both provided with internal threads suitable for allowing them to be threadably mounted coaxially upon the right quick-thread rod, so as to permit it to pass completely through and protrude from both sides of their respective hollow, threaded interiors.
Preferably, the left wing nut
56
and the equivalent right wing nut are each constructed to include (for the purpose of facilitating manual rotation, or other deliberate rotation, and subsequent stationary retention upon the particular quick-thread rod which passes through it) an upper wing
73
and a lower wing
74
that are relatively shaped and sized so that the lower wing
74
is significantly longer and heavier than the upper wing
73
, as illustrated in
FIG. 1
, or is otherwise configured so that after the completion of manual rotation (or other deliberate rotation) the lower wing
74
will tend, to a greater extent than the upper wing
73
, to maintain the lowermost position so as to help prevent the entire wing nut from further rotation. Such a preferred wing nut is advantageous for use with the preferred safety stanchion
10
, in part because it tends, more than an alternative form of wing nut with indistinguishable wings, to prevent excessive loosening despite inadvertently being struck and despite vibration sometimes transmitted to the safety stanchion
10
during normal use.
As best illustrated in
FIG. 1
, when the safety stanchion
10
is mounted upon the upper flange
28
of a horizontal I-beam
12
, the left quick-thread rod
62
is inserted longitudinally and completely through the hollow interior of the left rod receiver
50
, and it is also inserted longitudinally and completely through the hollow interior of the rod receiver
66
of the left flange hook assembly
64
. In an equivalent manner, although hidden from view in FIG.
1
and omitted from other views, when the safety stanchion
10
is so mounted the right quick-thread rod is inserted longitudinally and completely through the hollow interior of the right rod receiver
52
and the hollow interior of the rod receiver of the right flange hook assembly.
The left quick-thread rod
62
is of sufficient length so that, even after both such insertions have been completed, the left quick-thread rod substantially protrudes from the front face
75
of the left rod receiver
50
and substantially protrudes from the rear face
76
of the rod receiver
66
of the left flange hook assembly
64
. The right quick-thread rod is of equivalent length, and it is equivalently inserted longitudinally and completely through, so as to equivalently protrude from, the right rod receiver and the rod receiver of the right flange hook assembly.
As best illustrated in
FIG. 1
, when the safety stanchion
10
is mounted upon the upper flange
28
of a horizontal I-beam
12
, the left wing nut
56
and the threaded hexagonal left nut
70
are both threadably mounted to the left quick-thread rod
62
, and positioned so that the left rod receiver
50
and the left flange hook assembly
64
are between them, and so that the left wing nut
56
engages and presses firmly against the front face
75
of the left rod receiver
50
and the threaded hexagonal left nut
70
engages and presses firmly against the rear face
76
of the rod receiver
66
of the left flange hook assembly
64
. In an equivalent manner, although hidden from view in FIG.
1
and omitted from other views, when the safety stanchion
10
is so mounted, the right wing nut and the threaded hexagonal right nut are both threadably mounted to the right quick-thread rod, and positioned so that the right rod receiver
52
and the right flange hook assembly are between them, and so that the right wing nut engages and presses firmly against the front face
77
of the right rod receiver
52
and the threaded hexagonal right nut engages and presses firmly against the rear face of the rod receiver of the right flange hook assembly.
In an alternate embodiment of the invention of the '809 patent, the threaded hexagonal left nut
70
and the left flange hook assembly
64
are replaced with a functionally equivalent left threaded flange hook assembly
78
that is illustrated in FIG.
4
. Likewise, in that alternative embodiment the threaded hexagonal right nut and the right flange hook assembly are also replaced by a right threaded flange hook assembly (not shown), which is equivalent in size, shape and material to the left threaded flange hook assembly
78
illustrated in FIG.
4
.
As illustrated in
FIG. 4
, the left threaded flange hook assembly
78
includes a threaded hexagonal nut
79
, and a flange hook portion
81
that is welded to and depends from the underside of that threaded hexagonal nut
79
, and that is preferably cut or otherwise formed from a single plate or other piece of steel. Likewise, the right threaded flange hook assembly includes an equivalent threaded hexagonal nut, and an equivalent flange hook portion that is welded to and depends from the underside of that threaded hexagonal nut (and is likewise preferably cut or otherwise formed from a single plate or other piece of steel).
Referring now to
FIG. 5
, base assembly
34
also includes a left gusset
80
and a right gusset
82
of equivalent size and shape, each of which is preferably cut or otherwise formed in one-piece from a plate or other piece of steel.
When the safety stanchion
10
is properly mounted upon the upper flange
28
of a horizontal I-beam
12
, the left gusset
80
and the right gusset
82
stand vertically, as best illustrated in
FIG. 5
; however, they tend to converge toward one another, as best illustrated in
FIG. 6
, as they extend from their respective free edges
83
a
and
83
b
toward the tapered tubular post
36
. The preferred angle of their convergence is approximately as illustrated in
FIG. 6
, so that the left gusset
80
(as viewed in that figure) would preferably be angled approximately ten (10) degrees clockwise from a line drawn perpendicular to the upper front edge
54
of the upper portion
38
of the channel member
35
, but could be angled from five (5) to at least thirty (30) degrees clockwise. Similarly, the right gusset
82
(as viewed in that figure) would preferably be angled approximately ten (10) degrees counterclockwise from such a perpendicular line, but could be angled from five (5) to at least thirty (30) degrees counterclockwise.
The left gusset
80
is shaped and dimensioned to fit snugly against the exterior surfaces of the channel member
35
, as follows: as best illustrated in
FIG. 5
, the left gusset
80
fits snugly against the exterior of the vertical portion
40
of the channel member
35
; as best illustrated in
FIG. 6
, the left gusset
80
fits snugly against the top of the upper portion
38
of the channel member
35
; and as best illustrated in
FIG. 1
(although partially hidden from view), the left gusset
80
fits snugly against the horizontal underside of the lower portion
42
of the channel member
35
, and against the right surface (as viewed in that figure) of the vertical lip
46
.
In an equivalent manner, the right gusset
82
also fits snugly against the exterior of the vertical portion
40
of the channel member
35
, the top of the upper portion
38
of the channel member
35
, the horizontal underside of the lower portion
42
of the channel member
35
, and the right surface of the vertical lip
46
.
An important purpose of the left gusset
80
and right gusset
82
is to provide additional strength and stability to the base assembly
34
, and to the connection between the base assembly
34
and the tapered tubular post
36
. Accordingly, the left gusset
80
is welded to the channel member
35
wherever the channel member
35
and the left gusset
80
come into contact; and (as best viewed in FIG.
3
), the left gusset
80
is welded to the tapered tubular post
36
, with the weld
85
a viewed in that figure. Likewise, the right gusset
82
is welded to the channel member
35
wherever the channel member
35
and the right gusset
82
come into contact; and (as best viewed in FIG.
3
), the right gusset
82
is welded to the tapered tubular post
36
, with the weld
85
b viewed in that figure.
As previously noted, the safety stanchion
10
includes, in addition to its base assembly
34
, both the tapered tubular post
36
and the cap
22
. The cap
22
is preferably formed in one piece from a plate or other piece of steel that has been bent or otherwise formed to include an upper portion
86
and a lower portion
88
, which join at right angles as best viewed in FIG.
1
.
The lower portion
88
of the cap
22
, when viewed from above, is approximately square. Furthermore, the lower portion
88
is welded, and thereby firmly secured, to the upper terminus of the tapered tubular post
36
, and is thereby supported by the tapered tubular post
36
as shown in FIG.
1
.
As best illustrated in
FIG. 3
, the upper portion
86
of the cap
22
is approximately square (when viewed from the front or rear), and (as previously described) it is provided with two bores
24
a
and
24
b
that each pass completely through the upper portion
86
from front to back, for the purpose of receiving, respectively, clevis pins
20
a
and
20
b.
As previously described, the clevis pins
20
a
and
20
b
help to attach safety cables
14
a
and
14
b
to the cap, and therefore indirectly to the tapered tubular post
36
to which the cap
22
is welded.
As best illustrated in
FIG. 5
, the bottom of the tapered tubular post
36
is welded, and thereby firmly secured, to the top of the upper portion
38
of the channel member
35
that is included in the base assembly
34
.
When the safety stanchion
10
is properly mounted upon the upper flange
28
of a horizontal I-beam
12
, as best illustrated in
FIG. 1
, the tapered tubular post
36
extends upwardly from the top of the upper portion
38
of the channel member
35
, at an oblique angle that is preferably from about fifteen (15) degrees to about twenty (20) degrees from vertical (and, accordingly, that is from about seventy (70) to about seventy-five (75) degrees from horizontal). Such an oblique angle occurs because the end of the tapered tubular post
36
that is welded to the upper portion
38
of the channel member
35
is, before it is so welded, first cut, preferably at an angle approximately fifteen (15) to twenty (20) degrees from the horizontal.
Preferably, the tapered tubular post
36
is approximately forty-two inches (42″) in length. As illustrated in
FIG. 2
, throughout its length the tapered tubular post
36
has a cross section that is circular around both its exterior and interior circumferences. However, along its longitudinal axis, the tapered tubular post
36
is continuously tapered, giving it a frustoconical shape. At its bottom, it has an interior diameter of approximately two and seven-eighths of an inch (2⅞″); at its top, where it is welded to cap
22
, it has an interior diameter of approximately two and one-eighths of an inch (2⅛″).
Tapered tubular post
36
is preferably constructed from 11-gauge tubing of special high-strength, elastic steel (A595 grade), as purchased in tapered form from Valmont Industries of Valley, Nebr. However, it would be possible to construct the tapered tubular post from other energy absorbing steels or structural materials that have a high tensile strength to allow flexion and a large capacity to withstand, without fracturing, both flexion and permanent deformation when subject to the extreme forces of a worker's fall. To provide such elasticity and deformability in the post lengths typically contemplated by the subject invention, i.e. from about 30 to 42 inches, the tapered tubing should preferably be made from such energy absorbing steels and additionally have a wall thickness of less than 0.125 inches, however, not less than that provided by 15 gauge steel.
The tapered tubular post
36
is preferably constructed so as to flex and (if the load is sufficiently high) to permanently deform, controllably and without fracturing, in response to a substantial load (within its design limits) that is suddenly exerted upon it, as for example by the fall of a worker who is being supported by a safety cable that is being supported by the safety stanchion
10
.
As preferably constructed, the tapered tubular post
36
tends to flex and (if the load is sufficiently high) to permanently deform, in response to such loads within its design limits, over its length in the characteristic manner best illustrated in FIG.
3
: that is, it tends to flex and to permanently deform (as shown, for example, by the phantom lines in FIGS.
1
and
3
), with portions of the surface of the tapered tubular post
36
becoming permanently rippled
87
near the bottom of the tapered tubular post, in response to the stresses produced by the load (as shown, for example, in FIG.
3
). This tendency to flex and to permanently deform without fracturing enables the tapered tubular post
36
, when dealing with loads within its design limits, to absorb shock and to handle those loads without breaking in two, and without buckling or kinking at a single point so as to fold over abruptly.
In order to mount the safety stanchion
10
securely upon the upper flange
28
of a horizontal I-beam
12
, a worker preliminarily inserts the left quick-thread rod
62
completely through the first left rod receiver
50
and the second left rod receiver
66
of the left flange hook assembly
64
. Similarly, the worker preliminarily inserts the right quick-thread rod completely through the first right rod receiver
52
and the second right rod receiver of the right flange hook assembly.
In order to mount the safety stanchion
10
securely upon the upper flange
28
of the horizontal I-beam
12
, a worker will also preliminarily thread the left wing nut
56
upon the front portion of the left quick-thread rod
62
, and, in an equivalent manner, the right wing nut (not shown) on the front portion of the right quick-thread rod (not shown). In addition, the worker will also preliminarily thread the threaded hexagonal left nut
70
upon the rear portion of the left quick-thread rod
62
, and, in an equivalent manner, the threaded hexagonal right nut (not shown) upon the rear portion of the right quick-thread rod (not shown). The two bolts
48
a
and
48
b
, are also threaded into and through the two threaded hexagonal nuts
44
a
and
44
b
, respectively, and into and through the left bore
45
and the equivalent right bore (not shown), respectively, starting from below the lower portion
42
of the channel member
35
.
However, during the preliminary steps of the mounting process as described above, no wing nut, threaded hexagonal nut, bolt or other part should be tightened or otherwise positioned in any way that would interfere with any subsequent mounting step.
As another preliminary step in mounting the safety stanchion
10
securely upon the upper flange
28
of the horizontal I-beam
12
, a worker also preferably places the underside of the upper portion
38
of the channel member
35
so that, at least in part, it rests horizontally upon and above the I-beam's upper flange
28
, with at least part of the lower portion
42
of the channel member
35
suspended below the upper flange
28
(but above the I-beam's lower flange
30
) by the vertical portion
40
of the channel member
35
. In addition, the worker preferably places the left flange hook assembly
64
so that the underside of at least part of its rod receiver
66
rests horizontally above the I-beam's upper flange
28
, and so that at least part of its flange hook portion
68
is suspended below the upper flange
28
(but above the I-beam's lower flange
30
). In an equivalent manner, the worker also preferably places the right flange hook assembly (unless the alternative right threaded flange hook assembly is to be used) so that the underside of at least part of its rod receiver rests horizontally above the I-beam's upper flange, and so that at least part of its flange hook portion is suspended below the upper flange
28
(but above the I-beam's lower flange
30
).
The worker, to the extent possible, next moves the channel member
35
and the left flange hook assembly
64
relatively toward each other, along the left quick-thread rod
62
(while the underside of the upper portion
38
of the channel member
35
and, if it is present, the underside of the rod receiver
66
of the left flange hook assembly
64
, continue to rest, at least in part, horizontally above the I-beam's upper flange
28
, as previously described).
In an equivalent manner, the worker, to the extent possible, also moves the channel member
35
and the right flange hook assembly relatively toward each other, along the right quick-thread rod (while both the underside of the upper portion
38
of the channel member
35
and, if it is present, the underside of the rod receiver of the right flange hook assembly continue to rest, at least in part, horizontally above the I-beam's upper flange
28
, as previously described).
The worker continues, to the extent possible, the relative movement of the channel member
35
and the other assemblies as described in the immediately preceding paragraphs, until no more relative movement can occur because: (in the manner illustrated in
FIG. 1
) the flange hook portion
68
of the left flange hook assembly
64
has engaged and is positioned against the left side (as viewed in
FIG. 1
) of that upper flange
28
, and the vertical portion
40
of the channel member
35
has engaged and is positioned against the right side of that upper flange
28
(also as viewed in FIG.
1
); and, in an equivalent manner, although hidden from view in
FIG. 1
, the flange hook portion of the right flange hook assembly has engaged and is positioned against that same left side of that upper flange
28
.
Further threading or moving of the left quick-thread rod
62
will cause the threaded hexagonal left nut
70
to engage the rear face
76
of the rod receiver
66
of the left flange hook assembly
64
, with the flange hook portion
68
of the left flange hook assembly
64
engaging and positioned against the left side (as viewed in
FIG. 1
) of the upper flange
28
as previously described. Similarly, further threading or moving of the right quick-thread rod will cause the threaded hexagonal right nut to engage the rear face of the rod receiver of the right flange hook assembly (not shown), with the flange hook portion of the right flange hook assembly (not shown) engaging and positioned against the left side (as viewed in
FIG. 1
) of the upper flange
28
as previously described.
As the final step in mounting the safety stanchion
10
securely upon the upper flange
28
of the horizontal I-beam
12
as shown in
FIGS. 1 and 5
, the worker first tightens jaw opening adjustment bolts
48
a
and
48
b
until they contact the underside of the I beam's flange. There is no need to torque these bolts. Hand tightening is sufficient since the primary purpose of the bolts is to adjust the jaw opening to correspond to the flange thickness. Then, the left and right wing nuts are tightened either by hand or by manually spinning them and then preferably striking them with a simple tool to turn each wing nut another half a turn or so. It should be noted that after the wing nuts have been firmly tightened (i.e. by inwardly threading it on its respective threaded rod), it is ordinarily unnecessary (although possible) to separately tighten, in addition, the threaded hexagonal left nut
70
and the threaded hexagonal right nut. This aforementioned design is advantageous since in most situations safety stanchion
10
can be firmly secured to an I-beam by hand tightening only.
Safety stanchion
10
is relatively light and may be installed simply, quickly and by hand, by a single worker. It may be installed (preferably along with another, neighboring safety stanchion
10
joined to it by a safety cable
14
a
or
14
b
) upon an I-beam
12
before the I-beam has been hoisted into its final position, and then be hoisted with the beam, or it may instead be installed upon an I-beam
12
after the I-beam has already been installed in its final position in a superstructure.
Through its use, the safety stanchion
10
provides a unique fall protection system. In its simplest form, this fall protection system includes two of the safety stanchions
10
mounted in line along one or more horizontal I-beams
12
forming part of a bridge, building, longspan, girder, roof peak or other structure. Of course, any number of safety stanchions
10
can be mounted in a row without interruption, so that the fall protection system can be extended indefinitely.
Also, a separate fall protection safety cable can be horizontally extended perpendicularly to a line of safety stanchions
10
that are already connected by other safety cables
14
a
,
14
b
, so as to intersect and be joined at right angles to that line by attachment either to one of the safety stanchions
10
directly, or instead by fixed or sliding perpendicular attachment to one of the other safety cables
14
a
,
14
b
. Such a perpendicular attachment is made possible because the safety stanchion
10
is able to resist loads (within design limits), as generated by falls, in any compass direction for three hundred and sixty degrees (360°) around the stanchion.
In their preferred embodiments, neighboring safety stanchions
10
can be spaced up to eighty (80) feet apart, or may have any closer spacing that would be more useful to the user, with the exact spacing planned to control possible total fall distances. In one alternative, one or more safety stanchions
10
can be placed in an intermediate position, between other safety stanchions
10
, in order to lessen total fall distances or increase the maximum number of workers allowed within a given length of safety cable; as previously noted, such intermediate safety stanchions
10
could, but need not, be fitted with an alternative pass-through type cap such as that taught by U.S. Pat. No. 4,037,824, and could also, but need not, be fitted with a cap having more bores, so as to accommodate perpendicular cables as previously explained.
Once placed in a line, the safety stanchions
10
are used to vertically support and anchor one or more safety cables
14
a
or
14
b
sequentially above the particular I-beams
12
to which the safety stanchions
10
are attached, with any particular safety stanchion
10
ordinarily anchoring and supporting one or two safety cables (possibly together with one or more additional, perpendicular cables, as previously explained).
Ordinarily, each safety cable is supported and anchored at each end by a separate safety stanchion
10
, so that any two neighboring safety stanchions
10
form, together with the safety cable that links them, a so-called section.
When the preferred embodiment of the safety stanchion is properly used, up to two workers can be supported simultaneously by each section. Preferably, each worker obtains support by clipping to one of the supported and anchored safety cables
14
a
or
14
b
a conventional lanyard
26
that is attached, at its other end, to a harness worn by the worker. In one alternative, a worker could even hook his or her lanyard
26
directly to the safety stanchion
10
itself, if bore
24
a
or
24
b
was then unused and therefore available. Preferably, each lanyard
26
is five to six feet (5′ to 6′) in length, so as to limit possible fall distances. As previously noted, it is also preferred that conventional lanyards of the shock absorbing type be used. Alternatively, a retractable lanyard could be used to further limit free fall, total fall distance, and the forces on the system and the user.
In the preferred embodiment, each safety stanchion
10
supports and anchors its safety cables at a height of approximately forty-two inches (42″) above the upper flange
28
of the I-beam
12
to which the safety stanchion
10
is mounted.
At this height, a safety cable not only supports a worker's lanyard
26
but also provides the worker with a convenient hand grab to help the worker steady himself or herself. At this height, a safety cable also reduces free fall when compared to any shorter system or another lower tie-off point, thereby reducing the forces imposed, by a fall, upon the user and the fall protection system.
Once a worker has clipped his or her lanyard
26
to a supported and anchored safety cable
14
a
or
14
b
, the worker may walk along or work upon the I-beam
12
to which that safety cable is anchored and secured by way of the preferred safety stanchion
10
, with the worker's lanyard
26
sliding along the safety cable as the worker moves. The oblique angle at which the tapered tubular post
36
of the safety stanchion
10
extends above the base assembly
34
allows that tapered tubular post
36
, as well as the safety cables it supports, not only to provide a more conveniently placed hand grab, but also to facilitate the worker's passage along the beam with minimal interference from the safety stanchions
10
and the supported safety cables
14
a
or
14
b.
As a worker reaches a safety stanchion
10
, while moving along an I-beam
12
to which that safety stanchion
10
is mounted, the worker, before un-clipping his or her lanyard
26
from the particular safety cable
14
a
or
14
b
along which it has been sliding, first clips another, separate lanyard
26
, which is also attached to his or her harness, to the next safety cable
14
a
or
14
b
that extends in the desired direction of travel.
Only after the other, separate lanyard
26
has been so clipped does the worker un-clip his first lanyard
26
. In this fashion, the worker is clipped to a safety cable at all times, without interruption, so long as he or she is walking or working upon an I-beam
12
upon which safety stanchions
10
, with their accompanying safety cables, are mounted. Of course, this system anticipates that each worker will at all times have two separate lanyards
26
attached to his or her harness, for what is commonly called “100% fall protection.”
If a worker is properly clipped to a properly designed and installed safety system that incorporates safety stanchions
10
, the safety stanchions support the safety cable
14
a
or
14
b
to which the worker is clipped, and thereby limits the worker's fall. Furthermore, the preferred safety stanchion
10
may flex and may permanently deform, as previously described, to reduce and absorb the shock and sudden load created by the worker's fall. These abilities to flex and to permanently deform provide the preferred safety stanchion
10
with what is, in effect, a built-in shock absorber.
FIGS. 7-9
illustrate another safety stanchion
110
of the invention of the '809 patent which is ideally suited for mounting to a vertically disposed I-beam column
112
, as shown. A modified version, not shown, but quite similar may also be mounted to a horizontally disposed beam. The components of stanchion
110
(and its environment) which are identical or functionally equivalent to those of the previous embodiment will be identified with the same numbers used in the first embodiment. However, the numbers will be primed.
As shown, stanchion
110
has two primary components, a base assembly
134
and an L-shaped post
136
which is rigidly attached to base assembly
134
and which supports safety cables
14
a
′ and
14
b
′ at its upper end with a rigidly attached cap
22
′ in a manner similar to that described in the first embodiment.
Base assembly
134
is similar to base assembly
34
of the previous embodiment in that it also has a channel member
35
′ defining an open channel for receiving a side (not numbered) of flange
28
′ of I-beam column
112
. Base assembly
134
further includes a base plate
137
which is welded as shown in
FIG. 7
to the upper portion
38
′ of the channel member. As shown in
FIG. 7
, base plate
137
also has a pair of left and right gussets
80
′,
82
′ welded to its underside (not numbered) and to portions
40
′,
42
′ of channel member
35
′ which serve to strengthen and rigidify the base assembly. Gussets
80
′,
82
′ are also as shown in
FIGS. 7 and 8
welded along welds
139
to a square tubular sleeve
141
which in turn is received in and welded to the sides (not numbered) of a square bore
143
provided in base plate
137
. Gussets
80
′,
82
′ serve to rigidly maintain square tubular sleeve
141
in its perpendicular position relative to base plate
137
so that it is capable of supporting L-shaped post
136
, the lower end or leg
145
of which is slidably and telescopingly received therein. As shown, lower end
145
is held in place in square tubular sleeve
141
and thereby prevented from sliding out of the sleeve by a bolt/nut means
147
which passes through both sleeve
141
and lower end
145
.
Turning now to
FIG. 9
, it will be appreciated that base plate
137
also has a pair of rod receivers
50
′,
52
′ welded to its upper surface (not numbered). As shown, the rod receivers converge towards each other at an oblique angle of about 10 degrees in the manner previously described with respect to the first embodiment. As with the first embodiment, this arrangement serves to prevent “walking” or sliding of the base assembly down the column which is more of a problem in this embodiment since with a vertical column gravity is always acting on the base assembly.
As also shown, each rod receiver receives one end of a quick-thread rod
62
′ while the other end thereof is received in the bore (not numbered) of a flange hook
64
′. A nut
70
′ and a wing nut
56
′ are also provided for each quick-thread rod which are respectively threaded onto the opposite ends thereof. As will be appreciated and as previously described in connection with the first embodiment, when nuts
70
′ and wing nuts
56
′ of each quick-thread rod are tightened, the flange
28
′ of the column is clamped by (or between) the pair of flange hooks
64
′ and the channel member
35
′ of the base assembly. Note, a close comparison of the first and second embodiments will reveal that the location of the wing nuts
56
′ and nuts
70
′ are reversed in the two embodiments. This reversing or switching of their respective positions has no effect on the functionality of the respective embodiment, i.e. both fundamentally function the same. In both embodiments it will be appreciated that the wing nut is threaded onto the end of the quick-thread rod which extends over open space which as those skilled in the art will appreciate permits threading of the wing nut onto the rod.
FIG. 8
illustrates that the base assembly is also provided with a pair of threaded bolts
48
′, each of which is threadingly received in a nut
44
′ which is welded to the lower portion
42
′ of channel member
35
′. Each threaded bolt
48
′ passes through a bore (not shown) in the lower portion
42
′ of channel member
35
′ so that bolts
48
′ can be tightened against the underside surface of the column's flange
28
′ as such is shown in FIG.
7
.
When bolts
48
′ are tightened along with nuts
70
′ and wing nuts
56
′ on each quick-thread rod (note, the tightening of a wing nut will automatically tighten the associated nut
70
′ which has been threaded on the other end of the quick-thread rod), the base assembly will be securely affixed to the column. As previously mentioned in connection with the first embodiment, this unique design of the base assembly's means for securing or attaching the post to an I beam enables the base assembly to be securely attached to an I beam, even a vertical column as shown in the second embodiment, by simply hand tightening wing nuts
56
′ and bolts
48
′ or by simply banging on the wing nuts with a device. In most situations, there will be no need to torque these elements to a specific torque. This is advantageous in that it reduces the likelihood of a failure which could be caused by over tightening of the nuts or bolts which might strip the threads of the nuts or bolts.
Turning now to L-shaped post
136
, as shown in the drawings, L-shaped post
136
includes three basic parts; (1) the previously mentioned lower end or leg
145
of L-shaped post
136
which is slidably and telescopingly received in square sleeve
141
of the base assembly, (2) an upright square tube-like central base portion
149
which is rigidly affixed, i.e. welded, as shown by weld line
151
, at its lower end
153
to end
155
of lower leg
145
and (3) an upright square tube-like upper portion
157
, the lower end (not numbered) of which is received in and rigidly affixed to, i.e. welded, to the square tube-like central base portion
149
.
As can be visualized from the drawings, lower leg
145
is welded or joined to the central base portion at a right angle which is what provides post
136
with its L-shape. Cap
22
′ is rigidly attached, preferably welded, to the upper end (not numbered) of upper portion
157
. Thus, it will be appreciated that the entire L-shaped post
136
including cap
22
′ is fundamentally a one piece component with no moving parts. It however, as previously mentioned, is slidably and telescopingly received in square sleeve
141
of the base assembly. As such, its telescoping position within sleeve
141
can be adjusted by adjusting the depth to which the lower leg
145
is received in square sleeve
141
. In addition, the telescoping members
141
,
145
can be held or locked in any one of a number of desired positions by inserting bolt/nut means
147
through the appropriate bore
159
of a number of bores
159
provided in lower leg
145
as such is shown in FIG.
7
. As previously mentioned, bolt/nut means
147
locks or prevents slidable movement between leg
145
and sleeve
141
by passing through bores provided in both sleeve
141
and lower end
145
as such is shown in FIG.
8
.
The ability to adjust the position of the L-shaped post relative to the base assembly by adjusting the telescoping position of members
141
and
145
as indicated is advantageous because it enables one to position the safety cables
14
a
′ and
14
b
′ as desired. The ability to make such an adjustment in a column mounted application is particularly important because the horizontal I-beam (not shown) which is walked upon by the construction workers is not always in the same position relative to the column. That is, in some situations its outer edges may be closer to the vertical plane of the column and in other situations it may be farther away. Thus, the ability to adjust the position of the post enables one to adjust the position of the safety cables so that they are within the easy reach of a construction worker walking on the adjacent I-beam. This quite obviously is an important safety feature of this embodiment.
As will also be appreciated, the two piece nature of this embodiment makes it relatively easy to install since with two pieces each piece is significantly lighter than one combined unit. Also, all components of this embodiment i.e. safety stanchion
110
may be made from conventional steel. However, to reduce weight certain components may be made from aluminum or other alloys including thinner gauge steel with higher strength and flexion properties.
FIGS. 10 through 16
illustrate that several apparatus and methods of the present invention for mounting a safety stanchion to a concrete structure. As shown in
FIG. 10
, a safety stanchion
210
is provided for direct mounting to a flat surface
212
of a concrete floor or structure
214
. Stanchion
210
has a post
216
with means or cap
22
′ attached to its top end for supporting a safety cable. Post
216
may be of uniform width or frustoconical as shown in FIG.
1
. At its bottom end, post
216
is rigidly attached, preferably welded, to a base (not numbered) which includes a mounting plate
218
and several strengthening gussets
220
for mounting the stanchion to the concrete surface. Plate
218
has a generally flat bottom surface (not shown) for placement against the flat surface
212
of the concrete structure. The mounting plate also has a top surface
222
and a plurality of holes
224
extending through the plate from the bottom surface to the top surface.
As indicated in
FIG. 10
, stanchion
210
is secured to the concrete structure with four elongated bolts
226
which are anchored in the concrete structure as well as four wing nuts (not shown) such as wing nuts
56
of
FIG. 1
which thread onto the exposed threaded ends
228
of the bolts which preferably have aggressive threads as previously described. As shown in
FIG. 14
, bolts
226
are anchored a predetermined depth in the concrete structure with their first end
230
received in an hole or bore
232
provided in the concrete structure and their second threaded end
228
projecting out of the hole a distance which is sufficient to pass through and project outwardly from a hole
224
of the mounting plate
218
. As also shown, the bolts are secured in holes
232
with an epoxy or grout
234
such as those available from Dayton Superior of Dayton, Ohio which has been found to provide a good bond between the bolt and the concrete. To enhance the bond between the bolts and the concrete, the bolts are preferably threaded along their entire length. This provides the bolt with more surface area to which the epoxy can bond. The portion of the bolt embedded in the concrete should also preferably have a length to width ratio of at least 8 to 1 for a secure bond. In the alternative, a shorter headed bolt or a bolt with a nut on one end could be employed to increase adhesion or the force required to pull the member out of the concrete.
The method for mounting safety stanchion
210
to concrete structure
214
using the aforementioned components includes the steps of providing the four elongated holes
232
in the concrete structure with the holes arranged so that they align with holes
224
provided in the stanchion's mounting plate
218
. In addition, holes
232
are sized so that they are capable of receiving the first ends
230
of the bolts
226
and allowing the second threaded ends
228
of the bolts to project out of the holes a distance which is sufficient to enable the bolts to pass through and project outwardly from holes
224
of the mounting plate
218
. The method further includes the step of placing epoxy
234
, preferably quick cure type, and an elongated bolt
226
in each elongated hole
232
to adhesively secure the bolts in the holes. The stanchion is then mounted to the concrete structure by placing the stanchion's base on the exposed threaded ends
228
of the bolts so that the ends pass through and project outwardly from the holes
224
of the base's mounting plate
218
. Nuts, preferably wing nuts such as wing nuts
56
of
FIG. 1
, are then threaded onto the exposed threaded ends
228
of the bolts until the stanchion's base, i.e. mounting plate
218
, is securely attached to the concrete structure.
FIGS. 11 and 12
illustrate a structure referred to as an embed
310
for aligning elongated bolts
326
similar to bolts
226
and for insuring that the bolts are securely anchored to the concrete structure
214
′. As shown, embed
310
includes four elongated bolts
326
each of which has a first end or bolt head
330
for being embedded in the concrete structure and a second threaded end
328
for projecting outwardly from the concrete structure. Embed
310
also includes a preferably metal or plastic plate
340
which is provided with four holes (not numbered) for receiving bolts
326
which are rigidly connected to the plate (or held thereto) for assuring alignment of bolts with the plate
218
and holes
224
. Four nuts (not shown) such as wing nuts
56
of
FIG. 1
are also provided for threading onto the exposed ends
328
of the bolts to secure a safety stanchion such as stanchion
210
of
FIG. 10
to the concrete structure.
To mount a safety stanchion such as stanchion
210
to concrete structure
214
′ using embed
310
, one first pours concrete for forming the concrete structure. One then embeds or positions embed
310
in the poured concrete so that the threaded ends
328
of the embed project outwardly from the poured concrete and the alignment plate
340
is roughly at the same plane as the surface of the concrete. The user will then be assured, with a high degree of engineering certainty that without any field installation audits, testing or oversight that the design engineered strength is achieved based on the depth of embedment. A safety stanchion such as stanchion
210
is then mounted on the embedded embed by placing the base of the stanchion on the threaded ends
328
of the embed
310
so that the threaded ends pass through and project outwardly from the holes
224
of the stanchion's mounting plate
218
. Nuts such as wing nuts
56
of
FIG. 1
are then threaded onto the threaded ends
328
of the embed to secure the base of the stanchion to the concrete structure. Sufficient time should then be allowed to pass before use of the stanchion so that the poured concrete cures to its minimum design strength.
FIGS. 15 and 16
illustrate an alternative embed
410
of the present invention which differs from embed
310
in that instead of using elongated bolts such as bolts
326
embed
410
includes four elongated female threaded inserts
456
for receiving threaded male members
458
. In addition, instead of using a plate
340
embed
410
uses a plurality of preferably metal or plastic rods
460
or welded wire at one or more elevations within the concrete (two as shown in
FIGS. 15
,
16
) which are welded or otherwise attached to the exterior surface of the threaded inserts (or are holding the inserts) to align and space the inserts. The threaded members
458
have opposing first and second threaded ends
462
,
464
respectively, the first end of which is threaded or threadably received in a threaded insert
456
a predetermined distance so that the second threaded end projects outwardly from the threaded insert a predetermined distance. Four nuts (not shown) such as wing nuts
56
of
FIG. 1
are also provided for threading onto the exposed ends
464
of the threaded members to secure the stanchion to the concrete structure. Ideally aggressively threaded nuts or wing nuts should be used to enable the installer to fixedly secure the stanchion to the concrete without having to use any tools. The aggressive threads also enable the embeds to be used with concrete without having to worry about concrete contamination which in all likelihood would disable a standard or finely threaded bolt.
The method for mounting a safety stanchion such as stanchion
210
using embed
410
is similar to that for embed
310
in that concrete for forming the concrete structure
214
″ is first poured and then the embed is embedded in the poured concrete so that the threaded inserts are embedded in the poured concrete with the first ends
462
of the threaded members threaded into the inserts and the second threaded ends
464
of the threaded members projecting outwardly from the poured concrete a predetermined distance. The safety stanchion may then mounted to the embed by placing the stanchion's base on the exposed threaded ends
464
of the threaded members threaded into the inserts so that the threaded ends pass through and project outwardly from the holes of the stanchion's mounting plate. Aggressively threaded nuts or wing nuts as described above are then threaded onto the exposed threaded ends
464
of the threaded members to secure the stanchion's base to the concrete structure. Sufficient time should then be allowed to pass before use of the stanchion so that the poured concrete cures to its minimum design strength.
FIG. 13
illustrates a safety stanchion mounting adaptor
510
for enabling safety stanchions which are normally mounted to a structural member such as an I beam to be mounted to a concrete floor, concrete beam or girder or other form of structural concrete. As shown, mounting adaptor
510
includes an I beam segment
512
of the type having parallel upper and lower flanges
514
,
516
respectively which are connected by a center section
518
commonly known as the web. The I beam segment
512
preferably has a length less than four times the width of its upper and lower flanges. In addition, the lower flange
516
is provided with a plurality (four as shown) of holes
520
extending through the flange's cross-section for receiving threaded ends
228
so that the segment can be secured to a generally flat concrete floor or other flat concrete surface when nuts such as wing nuts
56
are threaded onto ends
228
.
In addition, the mounting adaptor preferably includes at least one strengthening plate
522
which is rigidly connected, preferably welded, to an end
524
of the adaptor. As shown, adaptor
510
has a pair of strengthening plates
522
with one welded to each end
524
of the adaptor's segment
512
. As also shown, the strengthening plates connect and are welded to both the upper and lower flanges
514
,
516
of the segment, thereby providing an extremely strong mounting adaptor. In addition, the strengthening plates serve to capture the mounted base of the stanchion within the ends of the adaptor, thereby preventing the stanchion from moving horizontally or walking as referred to earlier off an end of the beam.
To mount adaptor
510
to a concrete floor or other flat surface, one places the adapter on the flat surface so that the lower flange of the adapter is against the flat surface with the threaded ends
228
of bolts
226
extending through the adaptor's holes
520
. The adaptor is then secured to the flat surface by threading nuts such as wing nuts
56
of
FIG. 1
on the threaded ends
228
of the bolts. A safety stanchion of the type normally mounted to an I beam may then be mounted on the adaptor. This simply involves placing the safety stanchion's base on the upper flange of the adaptor and securing it to the upper flange as previously described in connection with the embodiments of
FIGS. 1 through 9
. It will also be appreciated that adaptor
510
can be mounted to a concrete surface with either of the foregoing embeds.
While preferred embodiments of the present invention have been shown and described, it is to be understood that this was done only by way of example, and not as a limitation upon the scope of the invention.
Claims
- 1. A safety stanchion apparatus for mounting to a concrete structure having a generally flat surface, said apparatus comprising:a frustoconically shaped tubular post having a first end for supporting a safety cable and a second end for attachment to a support base wherein said first end has an outside diameter which is less than that of said second end; means for supporting a safety cable at said first end of said post; a base attached to said second end of said post for mounting said post on a flat surface of a concrete structure, said base including a mounting plate having a generally flat bottom surface for placement against the flat surface of the concrete structure, said mounting plate also having a top surface and a plurality of holes extending through said plate from said bottom surface to said top surface, said post further being attached to said base so that said post extends above the base at an oblique angle relative to said flat bottom surface of said mounting plate of said base; and a plurality of bolts, each of which has a first end for receipt in a hole provided in the concrete structure and a second threaded end for projecting out of the elongated hole a distance which is sufficient to pass through and project outwardly from a said hole of the mounting plate; and a plurality of nuts for threading on the second threaded ends of said bolts; and a member selected from the group consisting of epoxy and grout for securing said first end of each bolt in a hole provided in the concrete structure.
- 2. A safety stanchion apparatus as claimed in claim 1 wherein said first end of said bolt is headed.
- 3. A safety stanchion apparatus as claimed in claim 1 wherein said threads of said nut are aggressive having 3 to 7½ threads per inch.
- 4. A safety stanchion as claimed in claim 3 wherein said nut is a wing nut having a first wing and a second wing with said first wing being heavier than said second wing.
- 5. A safety stanchion as claimed in claim 1 wherein said post is capable of inelastically deforming before failing.
- 6. A method for mounting a safety stanchion apparatus to a concrete structure having a generally flat surface, said method comprising:providing a safety stanchion apparatus including: a frustoconically shaped tubular post having a first end for supporting a safety cable and a second end for attachment to a support base wherein said first end has an outside diameter which is less than that of said second end; means for supporting a safety cable at said first end of said post; a base attached to said second end of said post for mounting said post on a flat surface of a concrete structure, said base including a mounting plate having a generally flat bottom surface for placement against the flat surface of the concrete structure, said mounting plate also having a top surface and a plurality of holes extending through said plate from said bottom surface to said top surface, said post further being attached to said base so that said post extends above the base at an oblique angle relative to said flat bottom surface of said mounting plate of said base; a plurality of bolts, each of which has a first end for receipt in a hole provided in the concrete structure and a second threaded end for projecting out of the elongated hole a distance which is sufficient to pass through and project outwardly from a said hole of the mounting plate; a plurality of nuts for threading on the second threaded ends of said bolts; and a member selected from the group consisting of epoxy and grout for securing said first end of each bolt in a hole provided in the concrete structure; providing a plurality of holes in a concrete structure having a generally flat surface with the holes being arranged so that they align with the holes provided in the mounting plate, each said hole also being sized to receive the first end of a bolt so that the second threaded end of the bolt projects out of the elongated hole a distance which is sufficient to pass through and project outwardly from a said hole of the mounting plate; placing said member selected from the group consisting of epoxy and grout and a said bolt in each said hole to adhesively secure a said bolt in each said hole; placing the base with attached post on the second threaded ends of said bolts secured in said holes so that the threaded ends pass through and project outwardly from the holes of the base's mounting plate; and threading the nuts onto the second threaded ends of the bolts projecting outwardly from the holes of the base's mounting plate to secure the base with attached post to the concrete structure.
- 7. A safety stanchion apparatus for mounting to a concrete structure having a generally flat surface, said apparatus comprising:a frustoconically shaped tubular post having a first end for supporting a safety cable and a second end for attachment to a support base wherein said first end has an outside diameter which is less than that of said second end; means for supporting a safety cable at said first end of said post; a base attached to said second end of said post for mounting said post on a flat surface, said base including a mounting plate having a generally flat bottom surface for placement against a flat surface, said mounting plate also having a top surface and a plurality of holes extending through said plate from said bottom-surface to said top surface, said post further being attached to said base so that said post extends above the base at an oblique angle relative to said flat bottom surface of said mounting plate of said base; and an embed rigidly supporting a plurality of bolts, each of which has a first end for being embedded in the concrete structure and a second threaded end for projecting outwardly from the concrete structure, said bolts also being supported by said embed so that the threaded second ends of said bolts are capable of aligning with the holes of the base's mounting plate and being received in the holes; and a plurality of nuts for threading on the second threaded ends of said bolts.
- 8. A safety stanchion apparatus as claimed in claim 7 wherein said threads of said nut are aggressive having 3 to 7½ threads per inch.
- 9. A safety stanchion as claimed in claim 7 wherein said nut is a wing nut having a first wing and a second wing with said first wing being heavier than said second wing.
- 10. A safety stanchion as claimed in claim 7 wherein said post is capable of inelastically deforming before failing.
- 11. A method for mounting a safety stanchion apparatus to a concrete structure having a generally flat surface, said method comprising:providing a safety stanchion apparatus including: a frustoconically shaped tubular post having a first end for supporting a safety cable and a second end for attachment to a support base wherein said first end has an outside diameter which is less than that of said second end; means for supporting a safety cable at said first end of said post; a base attached to said second end of said post for mounting said post on a flat surface, said base including a mounting plate having a generally flat bottom surface for placement against a flat surface, said mounting plate also having a top surface and a plurality of holes extending through said plate from said bottom surface to said top surface, said post further being attached to said base so that said post extends above the base at an oblique angle relative to said flat bottom surface of said mounting plate of said base; an embed rigidly supporting a plurality of bolts, each of which has a first end for being embedded in the concrete structure and a second threaded end for projecting outwardly from the concrete structure, said bolts also being supported by said embed so that the threaded second ends of said bolts are capable of aligning with the holes of the base's mounting plate and being received in the holes; and a plurality of nuts for threading on the second threaded ends of said bolts; pouring concrete for the concrete structure; embedding the embed in the poured concrete so that the first ends of the bolts are embedded in the poured concrete with the second threaded ends of the embed projecting outwardly from the poured concrete; placing the base with attached post on the second threaded ends of the bolts of the embed so that the threaded ends pass through and project outwardly from the holes of the base's mounting plate; and threading the nuts onto the second threaded ends of the bolts projecting outwardly from the holes of the base's mounting plate to secure the base with attached post to the concrete structure.
- 12. A safety stanchion apparatus for mounting to a concrete structure having a generally flat surface, said apparatus comprising:a frustoconically shaped tubular post having a first end for supporting a safety cable and a second end for attachment to a support base wherein said first end has an outside diameter which is less than that of said second end; means for supporting a safety cable at said first end of said post; a base attached to said second end of said post for mounting said post on a flat surface, said base including a mounting plate having a generally flat bottom surface for placement against a flat surface, said mounting plate also having a top surface and a plurality of holes extending through said plate from said bottom surface to said top surface, said post further being attached to said base so that said post extends above the base at an oblique angle relative to said flat bottom surface of said mounting plate of said base; and a plurality of threaded members having first and second threaded ends; an embed supporting a plurality of threaded inserts each of which threadably receives the first end of a threaded member so that the second threaded end of each threaded member projects outwardly from the threaded insert, said threaded inserts also being supported by said embed so that the threaded second ends of said received threaded members are capable of aligning with the holes of the base's mounting plate and being received in the holes; and a plurality of nuts for threading on the second threaded ends of said threaded members.
- 13. A safety stanchion apparatus as claimed in claim 12 wherein said threads of said nut are aggressive having 3 to 7½ threads per inch.
- 14. A safety stanchion as claimed in claim 12 wherein said nut is a wing nut having a first wing and a second wing with said first wing being heavier than said second wing.
- 15. A safety stanchion as claimed in claim 12 wherein said post is capable of inelastically deforming before failing.
- 16. A method for mounting a safety stanchion apparatus to a concrete structure having a generally flat surface, said method comprising:providing a safety stanchion apparatus including: a frustoconically shaped tubular post having a first end for supporting a safety cable and a second end for attachment to a support base wherein said first end has an outside diameter which is less than that of said second end; means for supporting a safety cable at said first end of said post; a base attached to said second end of said post for mounting said post on a flat surface, said base including a mounting plate having a generally flat bottom surface for placement against a flat surface, said mounting plate also having a top surface and a plurality of holes extending through said plate from said bottom surface to said top surface, said post further being attached to said base so that said post extends above the base at an oblique angle relative to said flat bottom surface of said mounting plate of said base; and a plurality of threaded members having first and second threaded ends; an embed rigidly supporting a plurality of threaded inserts each of which threadably receives the first end of a threaded member so that the second threaded end of each threaded member projects outwardly from the threaded insert, said threaded inserts also being supported by said embed so that the threaded second ends of said received threaded members are capable of aligning with the holes of the base's mounting plate and being received in the holes; and a plurality of nuts for threading on the second threaded ends of said threaded members; pouring concrete for the concrete structure; embedding the embed in the poured concrete so that the threaded inserts are embedded in the poured concrete with the first ends of the threaded members threaded into the inserts and the second threaded ends of the threaded members projecting outwardly from the poured concrete, placing the base with attached post on the second threaded ends of the threaded members threaded into the inserts of the embed so that the threaded ends pass through and project outwardly from the holes of the base's mounting plate; and threading the nuts onto the second threaded ends of the threaded members projecting outwardly from the holes of the base's mounting plate to secure the base with attached post to the concrete structure.
- 17. A safety stanchion for mounting to a concrete structure having a generally flat surface, said stanchion comprising:a frustoconically shaped tubular post having a first end for supporting a safety cable and a second end for attachment to a support base wherein said first end has an outside diameter which is less than that of said second end; means for supporting a safety cable at said first end of said post; a base attached to said second end of said post for mounting said post on a flat surface of a concrete structure, said base including a mounting plate having a generally flat bottom surface for placement against the flat surface of the concrete structure, said mounting plate also having a top surface and a plurality of holes extending through said plate from said bottom surface to said top surface, said post further being attached to said base so that said post extends above the base at an oblique angle relative to said flat bottom surface of said mounting plate of said base.
- 18. A safety stanchion as claimed in claim 17 wherein said post is capable of inelastically deforming before failing.
US Referenced Citations (15)