Information
-
Patent Grant
-
6644378
-
Patent Number
6,644,378
-
Date Filed
Friday, November 2, 200122 years ago
-
Date Issued
Tuesday, November 11, 200320 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Renner, Kenner, Greive, Bobak, Taylor & Weber
-
CPC
-
US Classifications
Field of Search
US
- 160 191
- 160 192
- 160 193
- 160 189
- 160 201
- 160 315
- 016 197
- 016 198
- 016 DIG 1
- 016 DIG 7
-
International Classifications
-
Abstract
A tensioning assembly for a door system, which includes an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly including a rotatable tension plate coupled to the counterbalance spring and rotatable relative to the counterbalance spring, the tension plate being selectively moveable between a disengaged position where the tension plate is freely rotatable and an engaged position where the tension plate is rotationally fixed to the frame; and a spring adapted to urge the tension plate toward the engaged position, whereby when in the disengaged position the tension plate is rotatable to adjust tension in the counterbalance spring and the tension plate is returned to the engaged position to maintain the tension.
Description
TECHNICAL FIELD
In general, the present invention relates to a tensioning device used to adjust the counterbalance tension in a door system. More particularly, the present invention relates to a tensioning assembly that adjusts tension on a torsional counterbalance spring employed to offset the weight of a sectional door movable between an open position and a closed position.
BACKGROUND ART
A familiar door system is a sectional door system, which includes a plurality of panels that pivot sequentially as the door travels between a generally vertical closed position and a generally horizontal open position. It will be appreciated that, due to the weight of these doors, an ordinary user may not be able to lift the door without assistance. Thus, to provide a counterbalancing force for the weight of the door, a counterbalancing system is attached to the door, as by a cable. Typically, the counterbalancing system includes a drive shaft or tube having one or more cable drums about which the cable is coiled or uncoiled depending on the direction of door travel. A counterbalance spring associated with the drive tube rotationally biases the drive tube to provide the counterbalancing force to the door. During installation or assembly of the door system, the spring is appropriately tensioned to provide the necessary counterbalancing force. Optimally, the counterbalance spring would have sufficient tension such that the door would fully close while only a small amount of force would be necessary to raise the door from the closed position. If the proper tension is not initially attained or the tension falls out of the proper range over time, the installer or user may make appropriate adjustment by way of a tensioning assembly.
In many instances, the door tensioning assembly includes a winding cone attached to the counterbalance spring at one end and displaying one or more receiving sockets for the insertion of a winding bar. To tension the counterbalance spring, a bar is inserted into the winding cone to give the installer the necessary leverage to torque the spring as necessary to apply or release tension within the spring. It will be appreciated, however, that the use of such a tensioning assembly carries inherent danger to the installer. To remove some of these safety concerns, wormgear drives are used in some cases to adjust the tension on the counterbalance spring. The wormgear allows the installer to adjust tension by a hand drill or a ratcheting wrench. In one design available in the industry, a door system having a torsion bar and spring assembly is used to transmit a counterbalancing force to a door with a wormgear tensioning assembly employed to adjust and maintain tension on the spring. The spring is fastened by hooks at both ends to prevent axial and longitudinal movement thereof. The wormgear rotates on a casting that forms the mount for the worm and is fastened to the torsion bar. In this design, separate fasteners are required at each point of torque transmission including the worm housing, the worm gear, the drums, cables, and cable pins. Also, the wormgear must have a relatively large diameter to handle the short torque movement of the large springs and drums. The size of the worm gear tensioning assembly of this design makes it unsuitable for lower headroom structures.
In another worm tensioning assembly, available in the industry, a wormgear device is provided for use with conventional garage door springs. This design requires the counterbalance spring be mounted over the drive tube. The wormgear is detachable, and all of the tensioning components are secured with fasteners. A counter shaft is used to reverse the rotation of the worm allowing fine adjustment of the spring tension. As in the previously described design, the spring must be secured from axial and longitudinal movement. An allowance, however, is provided for alteration of the length of the spring, as a result of winding.
Still other tensioning assemblies employ a ratcheting system to adjust tension on the counterbalance spring. Tension is applied in much the same manner as the winding cone tension assembly, but, to reduce the risk of injury to the installer, tension is maintained by the pawl's interaction with the gear teeth. One design, available in the industry, employs a collar, which can be slipped over the shaft around which the counterbalance spring is wound. The collar is fitted with a pair of ratcheting mechanisms and a device to hold these mechanisms in place. The collar is fastened to one end of the spring and turned to adjust the tension thereon. As the collar is rotated, the ratcheting mechanisms engage a boss on the collar to maintain the tension being applied to the spring.
Another design in the industry combines worm and ratchet systems in its tensioning assembly. This design includes a cone having a ring-shaped worm gear integrally formed thereon and attached to a counterbalance spring by way of a threaded connection. A worm drive is provided to rotate the ring-shaped spur gear. Rotation of the gear effects rotation of the cone, thereby adjusting tension on the counterbalance spring. A spring-loaded clip interacts with the gears to maintain the proper tension on the counterbalance spring.
In still another design, a ratcheting mechanism having a split housing is used to tension a counterbalance spring. Grooves are provided on either side of the split housing for receiving left and right hand ratcheting tools, which are simultaneously engaged and then used in sequence to create tension within the counterbalance spring. As in other designs, the ratcheting assembly prevents errant release of the spring's tension.
While worm and ratchet tensioning devices of the type discussed above and other variations remove some of the danger associated with the winding cone tensioning assembly, they are more complex and require more parts making them more costly to produce. Additionally, due to their complexity and the need to create sufficient mechanical advantage to tension the spring, these systems are often large relative to the drive tube, track and other door assemblies requiring additional space for their installation and making them unsuitable for a number of applications.
DISCLOSURE OF THE INVENTION
It is, therefore, an object of the present invention to provide a less complex tensioning assembly for an upwardly acting sectional door system having fewer parts and therefore reducing cost. Another object of the present invention is to provide a tensioning assembly that includes a tension plate, which selectively interacts with a counterbalance assembly to apply tension to the counterbalance spring, and has locking members adapted to maintain the tension on the counterbalance spring. Yet another object of the invention is to provide such a tensioning assembly that may be selectively engaged with the counterbalance assembly incrementally to adjust the tension thereon by rotating the tensioning assembly.
It is another object of the present invention to provide a more compact tensioning assembly for a sectional door. Yet another object of the present invention is to provide a tensioning assembly that is received within conventional track members associated with a sectional door and requires minimal side clearance for adjustment. Still another object of the present invention is to provide a tensioning assembly that has a radial dimension similar to that of conventional cable drums in a sectional door system. A further object of the present invention is to provide a tensioning assembly having a smaller radial dimension than the cable drums in a sectional door system. A still further object of the present invention is to provide such a tensioning assembly which can be employed with either torsional springs or extension springs and which does not have gears having a tendency to fail and require replacement when a spring fails.
In view of at least one of the foregoing objects, the present invention generally provides a tension assembly for a door system, which includes an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly including a tension plate coupled to the counterbalance spring and rotatable relative to the counterbalance spring, the tension plate being selectively moveable between a disengaged position where the tension plate is freely rotatable and an engaged position where the tension plate is rotationally fixed to the frame; a spring adapted to urge the tension plate toward the engaged position, whereby when in the disengaged position the tension plate is rotated relative to the counterbalance spring to adjust a tension therein and the tension plate is returned to the engaged position to maintain the tension.
The present invention further provides a tensioning assembly including an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly including a locking member attached to the counterbalance spring moveable to an engaged position to maintain a selected tension on the counterbalance spring, and a release assembly operative to selectively disengage the locking member allowing adjustment of tension within the spring.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a rear perspective view of a sectional door system including a door located within an opening defined by a plurality of framers, a counterbalance system operative to provide a balancing force for the weight of the door, and a tensioning assembly according to the concepts of the present invention operatively attached to the counterbalance system to adjust and retain the force applied to the door by the counterbalance system;
FIG. 2
is an enlarged fragmentary perspective view depicting the support bracket and tensioning assembly to the left of the door seen in
FIG. 1
depicting details of the tensioning assembly, including a release assembly that includes a tool having a handle portion coupled to a first plate having fingers that extend through slots formed in the bracket to selectively release the tension plate;
FIG. 2A
is an enlarged exploded perspective view depicting additional details of the tensioning assembly depicted in
FIG. 1
including a working end of the tool shown extending axially beyond the first plate and further depicting details of the slots formed to receive the fingers and a plurality of locking member receivers circumferentially spaced at equal angles about a circle located radially outward of the slots;
FIG. 3
is an enlarged exploded perspective view similar to
FIG. 2A
depicting additional details of the tensioning assembly including details of a tension plate having a plurality of locking members adapted to be received within the locking member receivers, when the tension plate is in an engaged position, a spring located between a cable drum and the tension plate to bias the tension plate toward engagement with the locking member receivers, and a winding shaft housed within the bore of the cable drum having a head portion that extends axially outward of the cable drum defining a socket formed therein for receipt of the working end of the tool having an interior surface that mates with the working end such that the tool may rotate the winding shaft to adjust tension on the counterbalance spring;
FIG. 3A
is an enlarged exploded perspective view similar to
FIG. 3
rotated 90° to show additional details of the tensioning assembly including details of the fingers extending from the first plate and extension of the working end of the tool through a circular bore formed in the first plate;
FIG. 4
is an exploded top plan view of the tensioning assembly as seen in
FIG. 2
with the cable drum removed to depict further details of the tensioning assembly including details of the winding shaft and head portion, and also depicting the locking members having ends sloped outward in a direction opposite the force of the torsional counterbalance spring;
FIG. 5
is a top plan view of the tensioning assembly seen in
FIG. 2
depicting details of the operation of the tensioning assembly including insertion of the fingers through the slots to incrementally release the locking members from the locking member receivers formed in the bracket by rotating the first plate, wherein the tensioning assembly is shown in a disengaged position where the spring between the cable drum and tension plate is compressed and the locking members have cleared the receivers;
FIG. 6
is a top plan view of the tensioning assembly similar to
FIG. 5
depicting the release assembly removed from the bracket and the tension plate returned to an engaged position under the force of the spring between the tension plate and the cable drum;
FIG. 6A
is an enlarged partially sectioned view of the area indicated in
FIG. 6
depicting further details of the tensioning assembly including details of the geometry of one locking member according to the present invention having a sloped end face and radially extending projection that rests against the bracket to provide a positive axial lock when the tension plate is in the engaged position;
FIG. 7
is a left side elevational view of the tensioning assembly as seen in
FIG. 6
depicting the tool rotated in a clockwise direction sufficient to cause shoulder pins extending from the first plate to contact the end of slots formed in the second plate and further rotated sufficient to cause the insertion of the fingers carried on the first plate through the slots to release the tension plate from the bracket such that the tension may be adjusted on the counterbalance spring;
FIG. 8
is a left side elevational view of the tensioning assembly similar to
FIG. 7
depicting the tool rotated to increase tension in the counterbalance spring; and
FIG. 9
is a left side elevational view of the tensioning assembly similar to
FIG. 7
depicting the tool rotated to reduce tension in the counterbalance spring.
BEST MODE FOR CARRYING OUT THE INVENTION
A tensioning assembly according to the concepts of the present invention is shown in the accompanying figures, and generally indicated by the numeral
30
. The tensioning assembly
30
is used in connection with a door system, generally indicated to by the numeral
10
in
FIG. 1
of the drawings. The door system
10
is positioned and mounted for opening and closing movement in a building, trailer or other structure by a peripheral door frame, generally indicated by the numeral
11
. The frame
11
consists of a pair of spaced vertical track framers
12
, that, as seen in
FIG. 1
, are generally parallel and extend vertically upwardly relative to a supporting surface such as a floor or the bed of a trailer (not shown). The vertical track framers
12
,
12
are spaced and joined proximate their vertical upper extremities by a header
13
to thereby define the generally inverted U-shaped frame
11
for mounting a door, generally indicated by the numeral
14
. The frame
11
may be constructed of metal or other relatively high-strength, rigid material for purposes of reinforcement, attachment to a building or vehicle, and facilitating the attachment of elements involved in supporting and controlling the door
14
. The header
13
may advantageously mount a counterbalance system, generally indicated by the numeral
15
that interacts with the door
14
to facilitate raising and lowering of the door
14
in a manner well known to persons skilled in the art. The counterbalance system
15
may be in accordance with the characteristics of a counterbalance system according to Applicant's Assignee's U.S. Pat. No. 5,419,010, which is shown for exemplary purposes and the disclosure therein incorporated herein by reference, with it being appreciated that any of a variety of different types of torsional or extension spring counterbalancing systems may be employed.
As seen in
FIGS. 1 and 2
, brackets
16
are provided to partially support roller tracks, generally indicated by the numerals
17
,
17
, which are positioned to either side of the door
14
. Each of the roller tracks
17
,
17
include substantially vertical track sections
18
,
18
formed in the vertical track framers
12
,
12
, substantially horizontal track sections
19
,
19
and transition track sections
20
,
20
interposed therebetween. As shown, the transition sections
20
,
20
may be integral with horizontal track sections
19
,
19
such that the sections
19
and
20
may be decoupled from vertical section
18
for storage and transport.
The roller tracks
17
,
17
in a known manner thus support and direct travel of the door
14
in moving from the closed vertical position depicted in
FIG. 1
associated with vertical track sections
18
,
18
of roller tracks
17
,
17
through transition track sections
20
,
20
to the open, horizontal position associated with horizontal track sections
19
,
19
. The ends of horizontal track sections
19
,
19
displaced from the door
14
are joined and supported by a back bar (not shown) attached directly or indirectly to the ceiling or walls of a structure in which the door system
10
is installed.
Door system
10
includes a counter balance system
15
, which may include a counterbalance spring
22
(
FIG. 3
) operatively attached at one end to a drive tube
23
and at an opposite end to tensioning assembly
30
such that an appropriate counterbalancing force may be developed in counterbalance spring
22
. Counterbalance tube
23
supports a pair of cable drums
24
, at either end to which a cable
25
that operatively interrelates the counterbalance system
15
to the door
14
is attached. A counterbalance system according to the concepts of Applicant's U.S. Pat. No. 5,419,010, is shown for exemplary purposes and incorporated herein by reference. While, in accordance with the concepts of U.S. Pat. No. 5,419,010, the counterbalance spring
22
is located within drive tube
23
, a counterbalance spring
22
located externally of a drive tube or solid drive shaft
23
can be employed with the tensioning assembly
30
in accordance with the concepts of the present invention. Cable
25
has one end attached to cable drum
24
and is received about the cable drum
24
with the other end of the cable
25
attached to the door
11
preferably proximate the bottom door section in a manner well known in the art. Cable drum
24
is rotationally coupled to drive tube
23
in accordance with Applicant's U.S. Pat. No. 5,419,010, by a drive tube
23
which is non-circular in cross-section, but, as will be appreciated, may be attached according other more commonly used methods, for example, a pin, set screw or key, such that cable drum
24
rotates with drive tube
23
to effect selective coiling and uncoiling of the cable
25
as the door
14
is raised and lowered. To protect and control the cable
25
, cable drums
24
may be covered by a shroud
27
. Tension in counterbalance system
15
sufficient to balance the weight of the door
14
is generated by relative rotation of the ends of the counterbalance spring
22
. As mentioned, one end of the counterbalance spring
22
is attached to the drive tube
23
for this purpose. The opposite end of counterbalance spring
22
attaches to tensioning assembly
30
that operates to develop the necessary tension within counterbalance spring
22
to counteract the weight of door
14
, as will be described below.
Referring particularly to
FIGS. 2A
,
3
and
4
, tensioning assembly
30
includes a winding shaft, generally indicated by the numeral
31
(FIG.
4
), located within a bore
32
of cable drum
24
and in registry with drive tube
23
. Winding shaft
31
is supported at its outward end
33
by bracket
16
and is axially fixed relative thereto by a clip, pin or similar device. In the embodiment shown, a portion of winding shaft
31
extends through and is received in a central bore B formed in bracket
16
, which is made circular to allow free relative rotation of the winding shaft
31
. A retaining ring
34
is attached to the portion of winding shaft
31
extending through bore B and fit within an annular notch
33
formed proximate the end of winding shaft
31
. A portion of the winding shaft is housed within cable drum
24
and may be journaled therein, as by suitable bearings, such that winding shaft
31
is freely rotatable relative to cable drum
24
. A free end of the counterbalance spring
22
is attached to winding shaft
31
, such that rotation of the winding shaft
31
will adjust the amount of tension in counterbalance spring
22
.
To maintain a selected tension on counterbalance spring
22
, tensioning assembly
30
further includes a tension plate
35
that is slidably received on and rotationally coupled to winding shaft
31
. Tension plate
35
may be keyed to winding shaft
31
, for this purpose, or a suitable receiver formed in either of the winding shaft
31
or tension plate
35
that cooperates with a coupling surface on the opposite member may be used. In the embodiment shown, winding shaft
31
has a hexagonal outer surface
37
at its head portion
38
on which tension plate
35
is received, by way of a correspondingly formed hexagonal socket
39
found therein. To rotationally fix winding shaft
31
and maintain tension within counterbalance spring
22
, tension plate
35
carries one or more locking members, generally indicated by the numeral
40
, that are adapted to engage locking receivers, generally indicated by the numeral
41
, formed in bracket
16
such that, when engaged (FIG.
6
), tension plate
35
, winding shaft
31
and the end of counterbalance spring
22
are held fixed against the torsional force, generally indicated by the arrow T in
FIGS. 7
,
8
and
9
, of counterbalance spring
22
on bracket
16
, such that, the torsional force T or tension within counterbalance spring
22
is maintained.
In the embodiment depicted in
FIG. 2A
, a plurality of locking receivers
41
are located radially equidistant and circumferentially spaced at equal angles along a circle connecting the receivers
41
. Tension plate
35
carries a number of locking members
40
equal to or less than the number of receivers
41
that project axially outward from tension plate
35
toward bracket
16
and may be in the form of circular-sectioned projections
42
. To accommodate projections
42
, locking receivers
41
may be provided with circular openings
43
through which projections
42
can extend. To reinforce the locking receivers
41
, gussets, generally indicated by the numeral
44
, may be provided adjacent openings
43
and be oriented such that their greatest dimension corresponds to the direction of force applied by projections
42
. For example, the gussets
44
, shown in
FIG. 7
, are of generally an oval-shape and aligned lengthwise substantially along the circle about which openings
43
are located. As best shown in
FIG. 6A
, diametrically opposed gusset portions
45
,
46
of gussets
44
may be formed on opposite sides of bracket
16
, such that a first gusset portion
45
is formed on a first side
47
and a second gusset portion
46
is formed on a second side
48
of bracket
16
. As best shown in
FIG. 6A
, gusset portions
45
and
46
may be formed such that they deviate axially from the surfaces
47
,
48
of bracket
16
to facilitate catching of the locking member
41
as it returns to the engaged position (FIG.
6
). For example, second gusset portion
46
may extend axially outward relative to tension plate
35
and radially inward to form an inwardly sloping surface relative to the inside surface
47
of bracket
16
that leads the locking member
40
into the receiver
41
. First gusset portion
45
may extend opposite second gusset portion
46
in an axial inward and radial inward fashion to improve the bite of the bracket
16
and catch the locking member
40
as it rotates into the engaged position. Additionally, the axial inward deviation of first gusset portion
45
provides clearance for a lip
55
, described below. The use of deviating gusset portions
45
,
46
reduces the likelihood that a locking member
40
would skip multiple receivers as it is returned to the engaged position.
To further facilitate engagement of the tension plate
35
, projections
42
are provided with a sloped end
49
that slopes axially outward in a tangential direction related to the clockwise or counter-clockwise direction of the torsional force T exerted by counterbalance spring
22
, such that the longer side
54
of projection
42
bears against the interior of opening
43
. Accordingly, the shorter side of sloped end
49
facilitates progressive release of the tension plate
35
, as will be described below. Sloped end
49
further may be used to allow tension to be applied to the counterbalance spring
22
. For example, as shown in
FIG. 6A
, since the torsional force of the counterbalance spring
22
acts to place the longer side
54
of projection
42
in contact with the bracket
16
, rotating the tension plate
35
in a direction opposite to the torsional force T would cause the sloped end
49
of the projection
42
to act on bracket
16
to gradually move the projection
42
axially inward such that the projection
42
does not impede rotation in this direction. An inwardly extending gusset portion
46
would facilitate such rotation by providing additional clearance for the shorter side of the projection
42
. As shown in
FIG. 6A
, projections
42
may be provided with a radially extending projection, for example, a lip
55
extending radially outward of sloped end
49
to act as a positive lock to axial movement of the tension plate
35
, when in the engaged position. Lip
55
extends radially outward from projection
42
in the direction of torsional force T, such that, when the tension plate rests in the engaged position, the torsional force T acting on tension plate
35
causes lip
55
to overlap a portion of bracket
16
. It will be appreciated that lip
55
may be carried on bracket
16
to the same effect. Using lip
55
to interlock the bracket
16
and tension plate
35
in this fashion requires an initial rotation of the tension plate
35
before the tension plate
35
is axially disengaged from bracket
16
. The effect of this is to cause the user to torque the tension plate
35
before the tension plate
35
is released, bracing the user against the torsional force T of the counterbalance spring
22
, thereby reducing the risk of injury or accidental release of the tension plate
35
. As an additional benefit, lip
55
reduces the likelihood of release of tension plate
35
in an uncontrolled manner, when the door system
10
is racked, such as may occur during an earthquake, in the case of a building, or when a truck having a door system
10
runs over a curb or other obstacle.
Once released, tension plate
35
may be moved axially such that the projections
42
clear the openings
41
of bracket
16
. At this point the user is free to apply or release tension on the counterbalance spring
22
by rotating winding shaft
31
. After tension on the counterbalance spring
22
is adjusted to the satisfaction of the user, with the projections
42
aligned with openings
41
, the tension plate
35
is slid axially outward until the projections
42
engage openings
41
locking the tension plate
35
against further rotation.
Alternatively, tension plate
35
may be biased toward engagement with bracket
16
. To that end, a spring, generally indicated by the numeral
50
, is provided between the cable drum
24
and tension plate
35
to urge tension plate
35
into engagement with bracket
16
. Spring
50
fits over the head portion
38
of winding shaft
31
and may be coaxial therewith. A radially extending flange
53
,
53
(
FIG. 4
) formed on head portion
38
(
FIG. 4
) or cable drum
24
and tension plate
35
facilitates location of spring
50
and provides a surface against which a first end
51
of the spring
50
may bear to create a biasing force applied to tension plate
35
at a second end
52
of spring
50
. It will be appreciated that other suitable bearing surfaces may be provided to perform the same function. These surfaces maybe formed by other projections on the head portion
38
, or the spring
50
may bear against cable drum
24
. The relative lengths of spring
50
and head portion
38
are controlled such that the spring
50
is able to urge tension plate
35
into engagement with bracket
16
. With the tension plate
35
biased into engagement with bracket
16
, an axial force in opposition to the spring force must be applied before the tension plate
35
is released, further improving the safety of the tensioning assembly
30
.
A release assembly, generally indicated by the numeral
60
, may be used to release tensioning assembly
30
in a controlled fashion. As best shown in
FIG. 2
, release assembly
60
includes a first plate
61
and a second plate
62
that are axially coupled to each other by means of a shoulder pin
63
, having a head portion and a shaft portion, carried on second plate
62
and received within arcuate slots
64
formed in first plate
61
. Slots
64
are sized to permit relative rotation between first and second plates
61
,
62
, as will be described more completely below. Second plate
62
carries a plurality of fingers, generally indicated by the numeral
65
, that extend axially inward toward tension plate
35
. Fingers
65
are in registry with corresponding finger slots
66
formed in bracket
16
such that fingers
65
may be selectively advanced through slots
66
to disengage tension plate
35
from bracket
16
. Fingers
65
extend axially from second plate
62
, and, to provide progressive axial insertion of fingers
65
, as second plate
62
is rotated, are disposed at acute angles relative to the inner surface
67
of second plate
62
. Each finger
65
is further oriented somewhat tangential in a single rotational direction. For example, fingers
65
, shown in
FIGS. 3A and 4
, each have a tip
68
directed in a counterclockwise direction. As further shown in
FIG. 6
, tip
68
may have an oblique outer surface
69
relative to the base portion
70
of finger
65
to provide greater clearance for the remainder of the tip
68
, as it enters wedge slot
66
. As shown, wedge slot
66
may include an inwardly sloping guide channel
72
projecting axially and radially outward from the bracket
16
adapted to direct fingers
65
through slots
66
during rotation of release assembly
65
. To provide an audible indication of the release of tension plate
35
from the bracket
16
caused by the insertion of the fingers
65
through slots
66
, the inner surface
73
of tip
68
may be provided with an angular notch
74
that catches against guide channels
72
at a selected distance from the tip
68
corresponding to the length of projections
42
on tension plate
35
(FIG.
5
).
As best shown in
FIGS. 5 and 6
, by rotating second plate
62
, the user may effect gradual protrusion of the fingers
65
beyond the inner surface of bracket
16
to force tension plate
35
axially inward against the force of spring
50
to a released condition(FIG.
5
), where locking members
41
clear receivers
40
releasing tension plate
35
from the bracket
16
and allowing adjustment of the tension on counterbalance spring
22
. Once the counterbalance spring
22
is properly tensioned, fingers
65
are retracted, as by rotating the second plate
62
in the opposite direction, allowing the tension plate
35
to reassume a locked condition (
FIG. 6
) by moving locking members
41
within receivers
40
.
A tool, generally indicated by the numeral
75
, may be provided to adjust tension on counterbalance spring
22
and may, to advance and retract fingers
65
, be coupled to release assembly
60
to effect rotation of the second plate
62
. As shown, tool
75
may include a handle attached to the release assembly
60
that provides sufficient leverage for the rotation of release assembly
60
against the force of the counterbalance spring
60
. Optionally tool
75
is inserted through release assembly
60
and provided with a key or bearing surface such that it may be rotationally coupled to first plate
61
. In the embodiment shown, tool
75
is coupled to the first plate
61
by a hexagonal outer surface
76
that mates with a correspondingly formed hexagonal bore
78
on first plate
61
. Second plate
62
may be provided with a circular bore
77
, such that tool
75
may extend therethrough and rotate freely within bore
77
effecting a delay between torquing of the tool
75
and release of tension plate
35
, as described in more detail below.
Slots
64
formed in first plate
61
allow rotation of the tool
75
and first plate
61
independent of second plate
62
until shoulder pins
63
engage either of the ends
81
,
82
of slot
64
. Thus, rotation of the tool
75
may occur independently of rotation of the second plate
62
, which would act to insert or retract fingers
65
. In operation, the tool
75
, with first and second plates
61
,
62
supported thereon may be initially placed in a position for insertion of the fingers
65
(FIG.
7
). As shown, in this position, the shoulder pins
63
engage the first end
81
of slot
64
. During rotation of the tool
75
from the position shown in
FIG. 7
to a released position, shown in
FIG. 8
, contact between the shoulder pin
63
and the slot end
81
is maintained such that the second plate
62
rotates with the tool
75
. As second plate
62
rotates, fingers
65
are progressively inserted with the oblique face
69
of tip
68
contacting tension plate
35
applying an axial force until the tension plate
35
is released (FIG.
8
). To attain the released position (FIG.
8
), the tool
75
must be rotated against the torsional force T of counterbalance spring
22
, as indicated by the arrow in
FIG. 8
, from the initial position (
FIG. 7
) to the released position (FIG.
8
). To reduce tension on the counterbalance spring
22
, after the tension plate is
35
is released, as described, the tool
75
is rotated in the direction of the torsional force T. With the shoulder pin
63
in contact with first end
81
of the slot
64
, in the released position (FIG.
8
), slot
64
provides a clearance for rotation of the tool
75
in the direction of the torsional force T without causing rotation of the second plate
62
. Therefore, the tool
75
may rotate in the direction of the torsional force T without retracting the finger
65
in a manner that would cause the tension plate
35
to engage bracket
16
. Once the shoulder pins
63
have reached the second end
82
of slot
64
, however, first plate
61
and second plate
62
become coupled, and further rotation of the tool
75
causes the second plate
62
to turn retracting fingers
65
returning the tension plate to the engaged position. For example, in
FIG. 9
, clockwise rotation of the tool
75
beyond the position shown, due to the contact of the shoulder pin
63
with a second end
82
of slots
64
, will cause second plate
62
to rotate in a counterclockwise direction withdrawing fingers
65
allowing spring
50
to urge the tension plate
35
into engagement with bracket
16
. It will be appreciated that additional adjustment of the tension of the counterbalance spring
22
beyond the increment provided by slot
64
may be made in a stepwise fashion by removing and resetting the tool
75
. To increase tension in the counterbalance spring
22
, the tension plate
35
may be released, as described above, and the tool
75
rotated against the torsional force T of the counterbalance spring. For example, referring to
FIG. 8
, further clockwise rotation of the tool
75
would increase the tension on the counterbalance spring
22
when using release assembly
60
, as in the case of reducing tension on counterbalance spring
22
, it may be necessary to add tension in a stepwise fashion by resetting tool
75
. It will be appreciated that if locking members
40
having sloped ends
47
are used, as described above, tensioning of the counterbalance spring
22
may occur without using the release assembly
60
. As mentioned, the sloped ends
49
of projections
42
may effect a gradual disengagement of tension plate
35
from bracket
16
by rotating the tension plate
35
in a direction opposite the torsional force T. In this way, the tool
75
, by itself, may be rotationally coupled to the tension plate
35
, as by inserting the working end
79
into an appropriately shaped socket, for example, hexagonal socket
78
, on winding shaft
31
, to which the tension plate
35
is rotationally coupled, and rotating the tool
75
until appropriate adjustment of the tension is achieved. It will be appreciated that application of tension to the counterbalance spring
22
may be limited by the confines of the structure in which the door system
10
is located. Therefore, it may be necessary to make stepwise adjustment of the tension by resetting the tool
75
as described above.
It will be appreciated that the use of tensioning assembly
30
flat plates, as opposed to gearing, as described above, results in a more compact tensioning assembly, which with the release assembly removed, occupies a small space between the cable drum
24
and bracket
16
. The entire tensioning assembly
30
may fit within the lateral bounds of framers
12
just above tracks
17
. While release assembly
60
is removable, when in use it too occupies a relatively small space. The plates
35
,
61
,
62
may be of similar size to cable drum
24
or have a diameter smaller than that of cable drum
24
such that no additional headroom is occupied by these components. In this way, a tensioning assembly
30
according to the present invention is suitable for applications where there is limited space near the upper extremity of door system
10
.
In light of the foregoing, it should be apparent that the invention as described and shown provides a new and useful improvement in the art. It should further be noted that various modifications and substitutions may be made in the present invention without deviating from the spirit thereof. Thus, for an appreciation of the scope of the present invention, reference should be made to the following claims.
Claims
- 1. A tensioning assembly for a door system, which includes an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly comprising:a rotatable tension plate coupled to the counterbalance spring, said tension plate being selectively moveable between a disengaged position where said tension plate is freely rotatable and an engaged position where said tension plate is rotationally fixed to the frame; a spring adapted to urge said tension plate toward said engaged position, whereby when in said disengaged position said tension plate is rotatable to adjust tension in the counterbalance spring and said tension plate is returned to said engaged position to maintain the tension.
- 2. The tensioning assembly of claim 1, wherein said tension plate includes at least one locking member adapted to couple said tension plate to the frame, when said tension plate is in said engaged position.
- 3. The tensioning assembly of claim 2 further comprising, a bracket supported on said frame having at least one receiver adapted to receive said locking member, when said tension plate is in said engaged position, whereby receipt of said locking member in said receiver couples said tension plate to the frame.
- 4. The tensioning assembly of claim 3, wherein said bracket has a plurality of circumferentially spaced receivers.
- 5. The tensioning assembly of claim 4, wherein said receivers have an opening adapted to receive said locking member.
- 6. The tensioning assembly of claim 5 further comprising, a gusset adjacent said opening.
- 7. The tensioning assembly of claim 6, wherein said gusset is oriented substantially lengthwise along a circle on which said openings are located.
- 8. The tensioning assembly of claim 5 further comprising, a first gusset portion and a second gusset portion, each located on opposite sides of said opening and opposite sides of said bracket.
- 9. The tensioning assembly of claim 8 wherein said first gusset portion extends axially toward said tension plate and radially inward relative to said opening; and wherein said second gusset portion extends axially away from said tension plate and radially inward relative to said opening.
- 10. The tensioning assembly of claim 9 further comprising, a projection carried on said locking member extending radially outward in the direction of the force of the counterbalance spring and adapted to protrude radially of said opening upon engagement of said locking member and contact said bracket.
- 11. The tensioning assembly of claim 10, wherein said locking member has an end, said end being sloped outward in the direction of the force of the counterbalance spring.
- 12. The tensioning assembly of claim 4, wherein said tension plate includes a plurality of axially outward extending locking members of equal or fewer number than said plurality of receivers.
- 13. The tensioning assembly of claim 12 wherein said locking members are projections and said receivers are openings through which said projections extend when said tension plate is in said engaged position.
- 14. The tensioning assembly of claim 1 further comprising, a bracket mounted on the frame a release assembly including a first plate rotatably supported adjacent said bracket having a plurality of fingers registrable with a plurality of finger receivers formed in said bracket, said fingers being insertably received in said finger receivers and adapted to be selectively advanced by rotating said first plate to urge said tension plate to a disengaged position.
- 15. The tensioning assembly of claim 14 further comprising, a tool selectively coupled to said first plate, said tool having a working end adapted to rotate said first plate and a handle extending from said working end.
- 16. The tensioning assembly of claim 15 further comprising, a second plate supported on said working end of said tool adjacent said first plate, wherein said second plate includes a plurality of circumferentially spaced arcuate slots;a plurality of shoulder pins extending from said first plate toward said second plate, said shoulder pins being slidably received in said slots whereby said first plate and said second plate are coupled to each other and partially rotatable with respect to each other; and said first plate being freely rotatable relative to said working end; said second plate being rotatably fixed relative to said working end, whereby rotation of said working end causes said second plate to rotate relative to said first plate until said shoulder pins engage said first plate causing said first plate to rotate with said second plate.
- 17. The tensioning assembly of claim 16 further comprising, a winding shaft rotatably supported on said bracket, said counterbalance spring being attached to said winding shaft, wherein said winding shaft is selectively coupled to said working end of said tool and rotatable therewith, and wherein said tension plate is rotationally fixed relative to said winding shaft and slidably received thereon.
- 18. The tensioning assembly of claim 17 wherein, said winding shaft defines a socket adapted to receive said working end of said tool formed in said winding shaft, wherein said working end of said tool is selectively insertably received within said socket to rotationally couple said working end to said winding shaft, whereby said working end of said tool is rotated to adjust the tension on the counterbalance spring.
- 19. The tensioning assembly of claim 1, wherein the counterbalance system has a cable drum and said tension plate has an outer dimension less than or equal to an outer diameter of the cable drum.
- 20. A tensioning assembly comprising, a bracket having a central bore, a plurality of slots circumferentially spaced relative to one another and spaced radially outward of said central bore, and a plurality of locking member receivers positioned radially outward of said central bore and circumferentially spaced relative to each other;a winding shaft rotatably supported by said bracket and connected to a counterbalance spring rotatable to adjust tension within said spring, said winding shaft having a socket for receipt of a tool and adapted to rotationally couple said tool to said winding shaft, whereby rotation of said tool adjusts the tension on said counterbalance spring; a tension plate slidably supported on said winding shaft and rotatably fixed thereto, said tension plate having a plurality of axially extending locking members extending toward said bracket, said locking members adapted to be received within said locking member receivers on said bracket to fix the rotational position of said winding shaft; and a release assembly adapted to selectively decouple said tension plate from said bracket, said release assembly including a first plate and a second plate, said first plate rotatably fixed to said tool and defining plural arcuate slots circumferentially spaced relative to one another, said second plate being coupled to said first plate by shoulder pins, said second plate carrying a plurality of fingers extending outwardly from said second plate toward said bracket and adapted to be received within said slots formed in said bracket, said fingers being circumferentially spaced with respect to one another wherein said fingers are adapted to advance upon rotation of said second plate in a first direction penetrating said slots and contacting said tension plate to urge said tension plate from a fixed rotational position.
- 21. A tensioning assembly for a door system, which includes an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly comprising:a tension plate coupled to the counterbalance spring and rotatable relative to the counterbalance spring, said tension plate being selectively axially moveable between a disengaged position where said tension plate is freely rotatable and an engaged position where said tension plate is rotationally fixed to the frame; and means for selectively fixing the tension plate in the engaged position, whereby when in said disengaged position said tension plate is rotated relative to the counterbalance spring to adjust tension therein and said tension plate is returned to said engaged position to maintain the tension.
- 22. A tensioning assembly for a door system, which includes an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly comprising:a tension plate coupled to the counterbalance spring and rotatable relative to the counterbalance spring, said tension plate being selectively moveable between a disengaged position where said tension plate is freely rotatable and an engaged position where said tension plate is rotationally fixed to the frame; means for selectively fixing the tension plate in the engaged position, whereby when in said disengaged position said tension plate is rotated relative to the counterbalance spring to adjust tension therein and said tens ion plate is returned to said engaged position to maintain the tension; and biasing means adapted to urge said tension plate toward said engaged position.
- 23. A tensioning assembly for a door system, which includes an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly comprising:a tension plate coupled to the counterbalance spring and rotatable relative to the counterbalance spring, said tension plate being selectively moveable between a disengaged position where said tension plate is freely rotatable and an engaged position where said tension plate is rotationally fixed to the frame; means for selectively fixing the tension elate in the engaged position, whereby when in said disengaged position said tension plate is rotated relative to the counterbalance spring to adjust tension therein and said tension plate is returned to said engaged position to maintain the tension; and release means for selectively urging said tension plate from the engaged position to a said disengaged position.
- 24. A tensioning assembly for a door system, which includes an upwardly acting door supported by a frame and connected to a counterbalance system having a counterbalance spring, the tensioning assembly comprising:a locking member attached to the counterbalance spring axially moveable to an engaged position to maintain a selected tension on the counterbalance spring; and a release assembly axially operatively movable to selectively disengage said locking member allowing adjustment of tension within the counterbalance spring.
- 25. The tensioning assembly of claim 24 further comprising, a receiver adapted to lockingly engage said locking member in the engaged position, wherein said release assembly is adapted to dislodge said locking member from said receiver to disengage said locking member.
- 26. The tensioning assembly of claim 25, wherein said release assembly includes a finger adapted to dislodge said locking member.
- 27. The tensioning assembly of claim 26, wherein locking member extends axially into said receiver and wherein said finger is moveable in the axial direction to dislodge said locking member.
- 28. The tensioning assembly of claim 27, wherein said finger is carried on a plate and extends axially outward from said plate and radially inward therefrom, said plate being rotatble to effect axial movement of said finger to dislodge said locking member.
- 29. The tensioning assembly of claim 28 further comprising, a tool rotatable to adjust tension on the counterbalance spring, said tool being selectively rotatably coupled to said plate, whereby rotation of said tool while said tool and said plate are coupled effects axial movement of said finger.
US Referenced Citations (19)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0 397 618 |
Nov 1990 |
EP |
0 495 499 |
Jul 1992 |
EP |