Information
-
Patent Grant
-
6485068
-
Patent Number
6,485,068
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Date Filed
Friday, December 12, 199726 years ago
-
Date Issued
Tuesday, November 26, 200221 years ago
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CPC
-
US Classifications
Field of Search
US
- 292 38
- 292 171
- 292 DIG 36
- 292 164
- 292 166
- 292 167
- 292 165
- 292 169
- 292 163
- 292 168
- 049 322
- 160 191
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International Classifications
-
Abstract
The apparatus is a fall arrestor and lockdown device for vertical lift doors, particularly single membrane fabric vertical lift doors. A pulley on a sensing arm engages the cable which raises and lowers the door. Alternatively, the sensing arm is directly attached to a belt. The sensing arm is mechanically linked to a spring loaded pin reciprocating within a tubular housing. When the cable or belt is tensioned, the sensing arm rotates upwardly to a position where the pin is retracted and the spring compressed thereby allowing the door to move vertically. However, when the cable or belt is not tensioned, the spring urges the pin to an extended position to engage regularly spaced apertures within the guide channel. When the cable or belt is not tensioned due to a cable or belt failure, the device operates as a fall arrestor. When the cable or belt is not tensioned because the door is fully lowered to the ground, the device acts as a lockdown device.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to a fall arrestor and lockdown device for vertical lift doors, particularly single membrane fabric vertical lift doors.
2. Description of the Prior Art
Many applications, such as aircraft hangars, today require large vertical lift doors. This need has been addressed by large single membrane fabric vertical lift doors. However, in the absence of proper safety equipment, such doors have the potential for rapid falls caused by cable or lift belt breaks. It is therefore important that such doors have fall arrestors which are responsive to cable or lift belt breaks. It is also important to realize that such fall arrestors ordinarily are activated only in unexpected cable or lift belt break situations. Such intermittent activation can lead to latent inoperability, such as contamination from debris due to lack of use, which is not detected prior to an unexpected cable or lift belt break.
Some prior art devices use friction methods for fall arrestor systems. These arrestor systems damage the door jamb and/or door beams thereby leading to extended down-time and costly repair. Further, they can allow the door leaf to continue falling after engagement by sliding on debris found in the jambs due to low maintenance or high contamination.
Additionally, it is important for such vertical lift doors to be automatically locked upon closing, so that surreptitious entrance cannot be gained by merely lifting the lower crossbar of the single membrane fabric vertical lift door.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a fall arrestor for vertical lift doors, particularly single membrane fabric vertical lift doors.
It is therefore a further object of this invention to provide a fall arrestor for vertical lift doors, particularly single membrane fabric vertical lift doors, which is simple in construction and reliable.
It is therefore a further object of this invention to provide a fall arrestor for vertical lift doors, particularly single membrane fabric vertical lift doors, which positively and reliably engages the door jamb without damage to the door jamb.
It is therefore a further object of this invention to provide a fall arrestor for vertical lift doors, particularly single membrane fabric vertical lift doors, which is periodically cycled to aid in detecting latent inoperability.
It is therefore a further object of this invention to provide a fall arrestor for vertical lift doors, particularly single membrane fabric vertical lift doors, which can be reset quickly after repair of a failed cable or lift belt.
It is therefore a further object of this invention to provide a lockdown device for vertical lift doors, particularly single membrane fabric vertical lift doors.
It is therefore a final object of this invention to provide a fall arrestor and lockdown device for vertical lift doors, particularly single membrane fabric vertical lift doors, which is relatively inexpensive to manufacture.
These and other objects are attained by a fall arrestor and lockdown device which is integral with the guide system on the bottom beam of the door and rigidly attached thereto. The fall arrestor and lockdown device includes a spring activated pin device which is attached by mechanical linkage to a rotatable cable or lift belt tension sensing arm. A wire rope or cable passes through the sensing arm. Alternatively, a lift belt can be attached directly to the arm. When the cable or lift belt is “charged” (tension is applied to the cable or lift belt), the sensing arm rotates thereby moving the linkage, retracting the pin and compressing the coil spring. The pin retracts to clear apertures that are placed in the door jamb according to door-width parameters. In the event that the cable or lift belt breaks, the force of the compressed coil spring overcomes the lift applied by the cable or lift belt in the sensing arm and consequently the pin extends. With pressure applied by the coil spring to the pin, the pin is forced outwardly against the door jamb tracking until it reaches an aperture in the jamb. The pin then fires into the aperture where it then comes to rest upon hitting the edge of the side frame. Upon activation of the arrestor system, the beam fall due to cable or lift belt failure is arrested.
The lockdown feature is accomplished when the door reaches its bottom height. The cable or lift belt will lose tension due to the transfer of load from the cable to the ground. This load transfer allows the sensing arm to articulate or rotate in a controlled manner. The pin thereby extends into a jamb placed into the side frame thereby locking the door. This locking provides resistance to unwanted intrusion as well as resistance to beam lift due to catenary forces form wind loading to the fabric. Upon reinitiation of the door cycle, the tension from the cable or lift belt again charges the arrestor system retracting the pin for the arrestor mode.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:
FIG. 1
is a plan view of a vertical lift door using the fall arrestor and lockdown device of the present invention.
FIG. 2
is an exploded perspective view of the fall arrestor and lockdown device of the present invention.
FIG. 3
is a perspective view of the fall arrestor and lockdown device of the present invention with the pin in a retracted position.
FIG. 4
is a perspective view of the fall arrestor and lockdown device of the present invention with the pin in an extended position.
FIG. 5
is a side plan view of the fall arrestor and lockdown device of the present invention with the pin in an extended position through the aperture in the guide channel of the door jamb, the guide channel being shown in phantom.
FIG. 6
is a top plan view of the fall arrestor and lockdown device of the present invention with the pin in an extended position.
FIG. 7
is a rear plan view, partly in cross section along section
7
—
7
of
FIG. 6
, of the fall arrestor and lockdown device of the present invention with the pin in an extended position.
FIG. 8
is a side plan view, partially in phantom, of an alternative embodiment of the fall arrestor and lockdown device of the present invention with the pin in a retracted position.
FIG. 9
is a top view, partially in phantom, of the alternative embodiment of the fall arrestor and lockdown device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail, wherein like numerals refer to like elements throughout the several views, one sees that
FIG. 1
shows a vertical lift door
100
, typically made of a single membrane fabric
102
with a lower metallic beam
104
riding within guide channels
106
,
108
which are fixed to wall
200
. Guide channels
106
,
108
have regularly spaced apertures
110
as illustrated in phantom in FIG.
5
. Fall arrestors and lockdown devices
10
,
10
′ are rigidly attached to (or integral with) both sides of lower metallic beam
104
. Cable
112
is fixed at a first end
114
to a first side of wall
200
at a position proximate to the upper end of vertical lift door
100
. Cable
112
extends vertically downward from first end
114
, passes through fall arrestor and lockdown device
10
, extends horizontally immediately above lower metallic beam
104
, passes through fall arrestor and lockdown device
10
′, and extends vertically upward to second end
116
which is engaged by spool
118
of rotary motor
120
. Vertical lift door
100
is raised and lowered by winding and unwinding cable
112
about spool
118
.
FIG. 2
is an exploded perspective view of the fall arrestor and lockdown device
10
. Horizontally opposed vertical rectangular plates
12
,
14
, spaced apart by horizontal posts
16
,
18
,
20
,
22
, provide the structural support for fall arrestor and lockdown device
10
. Posts
16
and
18
pass through and are rigidly attached to upper roller support
24
. Forward end
26
of upper roller support
24
includes axis
28
about which upper roller
30
is journalled for rotation. As shown in
FIG. 5
, upper roller
30
travels within guide channel
106
.
H-shaped support
32
comprises two vertical members
34
,
36
(see
FIG. 7
) and a horizontal cross member
38
. Flange
37
extends from vertical member
36
. H-shaped support
32
secures lower roller support
40
underneath and parallel to upper roller support
24
. Vertical members
34
,
36
are welded or otherwise fastened to the sides of upper roller support
24
and lower roller support
40
. Forward end
42
of lower roller support
40
includes axis
44
about which lower roller
46
is journalled for rotation. As shown in
FIG. 5
, lower roller
46
travels within guide channel
106
.
Additionally, upper central vertical web portion
48
extends from a central lower portion of upper roller support
24
to an upper portion of pin tubular housing
50
and lower central vertical web portion
51
extends from a lower portion of pin tubular housing
50
to lower roller support
40
.
Horizontal cross member
38
passes below upper roller support
24
and is integral with a portion of upper central vertical web portion
48
and spaces vertical members
34
,
36
apart from each other.
Pin tubular housing
50
includes forward section
52
through which pin
54
reciprocates and rearward section
56
of increased diameter which houses coil spring
58
(see
FIG. 2
) which urges pin
54
to the extended position and which is compressed when pin
54
is in the retracted position. Pin tubular housing
50
further includes opposed lateral slots
60
,
62
.
Pin
54
includes integral opposed lateral linkage pins
64
,
66
which extend through opposed lateral slots
60
,
62
, respectively.
Sensing arm
68
includes two parallel arm members
70
,
72
which on a proximal end
74
(see
FIG. 6
) are journalled for rotation about post
22
. Distal end
76
of sensing arm
68
includes an axle
78
about which pulley
80
rotates. Pulley
80
engages cable
112
. Linkage arms
82
,
84
are likewise journalled for rotation about post
22
, are mechanically secured to sensing arm
68
via rod
86
and thereby rotate in concert with sensing arm
68
. Linkage arms
82
,
84
include linkage slots
86
,
88
, respectively which are engaged by lateral linkage pins
64
,
66
, respectively, which are integral with pin
54
.
The position of sensing arm
68
is responsive to the tension on cable
112
. Further, the sensing arm
68
is mechanically linked to pin
54
via bar
86
, linkage arms
82
,
84
and lateral linkage pins
64
,
66
. Therefore, when there is tension on cable
112
, the sensing arm
68
is rotated upwardly to the position shown in FIG.
3
. This position, via the above described mechanical linkage, retracts pin
54
into pin tubular housing
50
and compresses coil spring
58
within rearward section
56
of pin tubular housing
50
. The upward rotation of sensing arm
68
is stopped by the lateral linkage pins
64
,
66
abutting the rearward sections of slots
60
,
62
. Additionally, a mechanical stop can be provided in the interior of plate
12
.
FIG. 3
, with the upwardly rotated sensing arm
68
and retracted pin
54
, is the configuration of fall arrestor and lockdown device
10
when the door
100
is raised via rotary motor
120
and tension is applied to cable
112
by the weight of the lower metallic beam
104
.
FIG. 4
, with the horizontal sensing arm
68
and extended pin
54
, is the configuration of the fall arrestor and lockdown device
10
when tension is not applied to sensing arm
68
via cable
112
and coil spring
58
forces pin
54
into an extended position. Additionally, via the mechanical linkage, sensing arm
68
is forced to a horizontal position by coil spring
58
. This occurs in two situations. The first situation is when cable
112
breaks or becomes unsecured while the door
100
is lifted. In this situation, the pin
54
is fired into an aperture
110
of guide channel
106
or
108
thereby arresting the fall of door
100
, and device
10
acts as a fall arrestor. The second situation is when door
100
is fully lowered and the weight of lower metallic beam
104
comes to rest on the ground. The pin
54
then extends and inserts into an aperture
110
of guide channel
106
or
108
which is positioned near the ground. Device
10
acts as a lockdown device in this situation. When the door
100
is subsequently raised, the sensing arm
68
is tensioned by the cable
112
and the pin
54
automatically retracts allowing door
100
to be lifted. As the second situation occurs every time that the door
100
is closed, the fall arrestor and lockdown device
10
is regularly and periodically cycled without any special testing required. This helps assure that fall arrestor and lockdown device
10
properly maintained.
An alternative embodiment is disclosed in
FIGS. 8 and 9
and is particularly adapted to use with lift belts
113
which are directly attached to the sensing arm
68
by pivotally mounted clamp
81
, in place of cable
112
passing through the pulley
80
of the embodiment shown in the previous figures. The use of the term “alternative” is intended in no way to imply that this embodiment is less desirable. It is merely used with a different drive system (lift belts versus cables). In the alternative embodiment, typically each side of the vertical lift door
100
has an individual fall arrestor and lockdown device
10
with an attached lift belt
113
which leads to a spool (not shown) above the door
100
. The spools are typically driven by a common axle (not shown), driven in turn by a rotary motor (similar to element
120
of FIG.
1
). Operation of the alternative embodiment is otherwise functionally identical or equivalent to that of the embodiment of the previous figures.
Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention has been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
Claims
- 1. A vertical lift door in combination with a device for arresting the movement of the vertical lift door, the door being operated by a cable or belt connected to the door such that it is used to vertically lift the door, whilst said door travels in oppositely disposed lateral guide members, the device comprising:an arm coupled to the cable or belt which is used to vertically lift the door, said arm having a first position and a second position; a latching pin being operatively coupled to said arm and responsive to said positions of said arm, said latching pin having a retracted position when said arm is in said first position and an extended position when said. arm is in said second position; biasing means for moving said pin from the retracted position to the extended position; wherein said arm is in said first position thereby said latching pin is in said retracted position when the cable or belt is tensioned by the weight of the door when the door is raised or lowered and wherein when said arm is in said second position said pin is moved laterally by the biasing means from the retracted position to the extended position when the cable or belt is relatively untensioned; and wherein when said pin is in said extended position said pin engages a laterally adjacent aperture located in at least one of said lateral guide members.
- 2. The device of claim 1 wherein said latching pin is mechanically linked to said arm.
- 3. The device of claim 2 wherein said latching pin reciprocates within a tubular housing between said extended position and said retracted position.
- 4. The device of claim 3 wherein said biasing means urges said latching pin to said extended position.
- 5. The device of claim 4 wherein said biasing means for urging comprises a coil spring.
- 6. The device of claim 5 wherein said latching pin includes at least one linkage pin extending perpendicularly from said latching pin through at least one lateral slot in said tubular housing.
- 7. A vertical lift door in combination with a device for arresting the movement of the vertical lift door, the door being operated by a cable or belt connected to the door such that it is used to vertically lift the door, the device comprising:an arm coupled to the cable or belt which is used to vertically lift the door, said arm having a first position and a second position; a latching pin mechanically linked and responsive to said positions of said arm, said latching pin reciprocating within a tubular housing and having a retracted position when said arm is in said first position and an extended position when said arm is in said second position; a least one linkage pin extending perpendicularly from said latching pin through at least one lateral slot in said tubular housing; at least one linkage element which moves in concert with said arm, said linkage element including at least one linkage slot engaging said linkage pin, whereby movement of said arm affects linear reciprocation of said latching pin within said tubular housing; means for urging said latching pin to said extended position, thereby urging said arm to said second position when the cable or belt is relatively untensioned; wherein said arm is in said first position thereby said latching pin is in said retracted position when said cable or belt is relatively tensioned by the weight of the door when the door is raised or lowered, and wherein when said arm is in said second position said latching pin is in said extended position when said cable or belt is relatively untensioned; and wherein when said latching pin is in said extended position said latching pin is adapted to engage a laterally adjacent aperture.
- 8. The device of claim 7 wherein said arm further includes the pulley designed to engage a cable or belt.
- 9. The device of claim 7 wherein said arm includes means for mechanically coupling it to the cable or belt.
- 10. The device of claim 8 or claim 9 wherein said arm rotates between said first position and said second position.
- 11. The device of claim 10 further including an upper roller support structure above said tubular housing and a lower roller support structure below said tubular housing, said upper and lower roller support structure including rollers for engaging guide channels.
US Referenced Citations (11)