Patent Application
20120151714
The present invention relates generally to roll-up doors, and, more particularly, to improved hold-open devices that are adapted to selectively hold a roll-up door in an overhead out-of-the-way position so as to maximize the projected cross-sectional area of the access opening in which the door is mounted.
Roll-up doors are widely known, and are commonly used to selectively close access openings in various bodies. Some bodies are stationary, and the roll-up door is used, for example, to selectively control access to a garage or warehouse. Other bodies are mounted on vehicles, such as on cargo-carrying trucks and trailers.
In either case, it is sometimes desired to hold the roll-up door in a particular position such that the projected cross-sectional area of the body access opening will be maximized so as to facilitate the ingress or egress of goods. This position may be other than the normal lifted overhead position of the door.
To this end, various types of hold-open devices for roll-up doors have been developed.
In one form of a prior art hold-open device, a clevis member was welded to the bottom of an arcuate portion of the track between the lower vertically-disposed portion and the overhead horizontally-disposed portion. An intermediately-pivoted dogleg-shaped clevis arm was mounted on the clevis member, and was weight-biased such that a striker on one end of the arm would move toward a catch mounted on the door. When the door was moved overhead, the catch had a forwardly- and downwardly-facing inclined surface, and a rearwardly-facing abutment surface. A release cable or lanyard was attached to the underweighted arm portion adjacent the striker. The door could be moved upwardly to an overhead out-of-the-way position. As it moved toward this position, an edge on the arm-mounted striker would ride up the inclined surface on the catch. At the end of this motion, the weighted arm would pivot, and the striker edge would face and engage the abutment surface to hold the door in the overhead out-of-the-way position. However, it was found that sometimes the striker edge would only marginally engage the catch abutment surface so that the door might be insecurely held in the overhead position, particularly if the movement of the weighted arm was slowed, as by dirt in the pivotal connection between the arm and the clevis member.
In another form of a prior art hold-open device, a latch mounted on the upper edge of the uppermost panel of the door was arranged to engage a keeper. In other words, a version of the latch-keeper mechanism on the lowermost door panel was again provided on the uppermost door panel to selectively hold the door in the overhead out-of-the-way position. While effective to hold the door, this arrangement added unnecessary cost and weight to the door. Moreover, it is difficult to properly and effectively brace a latch bar in the center of an eight-foot span of cargo body that is essentially frameless. A “slam” lock can displace or distort the catch bar to the point of being inoperative. Also, this design places an obstacle right in the middle of the freight area, and is of concern because of the possibility of being hit by freight or a fork lift.
Accordingly, it would be desirable to provide an improved hold-open device for a roll-up door that could selectively hold a door in an overhead out-of-the-way position.
With parenthetical reference to the corresponding parts, portions or surfaces of the disclosed embodiment, merely for purposes of illustration and not by way of limitation, the present invention provides an improved hold-open device (50) for holding a roll-up door (55, 56) in an overhead out-of-the-way position in a body, the door being mounted for movement within a track (51) having a vertical portion (52), an arcuate portion (53) and an horizontal portion (54).
The improved device broadly includes: a plate (62) mounted on one of the track and cargo body; an arm (68) pivotally mounted on the plate; a striker (64) mounted on the door, the striker having an inclined surface (79) and an abutment surface (80); a stop (70) mounted on the arm, the stop having an edge adapted to engage the striker surfaces; and at least one spring (65) urging the arm to move such that the edge will engage one of the striker surfaces.
The device may further include a first stop (71′) mounted on the plate for limiting pivotal movement of the arm in one angular direction.
The device may further include a second stop (71″) mounted on the plate for limiting pivotal movement of the arm in the opposite angular direction.
The first and second stops may be mounted on an arm stop (71) secured to the plate.
A marginal end portion of the plate may engage a portion of the track in area contact, and may be welded to the track portion. The track portion may be on the horizontal portion.
A distal end portion (68) of the arm may be arranged adjacent the opening of the cargo body that is closed by the roll-up door.
The spring may act between said plate and door.
In a presently-preferred embodiment, two springs (65, 65) urge said arm to move relative to said plate.
The inclined surface may face forwardly and downwardly, and the abutment surface may face rearwardly toward the access opening in which the roll-up door is mounted, when the door is in the overhead position.
The improved device may be mounted in a static structure, such as garage or warehouse, or may be mounted in a vehicle-mounted cargo body, such as in a truck or trailer.
Accordingly, the general object of the invention is to provide an improved hold-open device for selectively holding a roll-up door in an overhead out-of-the-way position.
Another object is to provide an improved hold-open device that is relatively simple and uncomplicated in structure and construction, and that is reliable in operation.
These and other objects and advantages will become apparent from the foregoing and ongoing written specification, the drawings and the appended claims.
At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions or surfaces consistently throughout the several drawing figures, as such elements, portions or surfaces may be further described or explained by the entire written specification, of which this detailed description is an integral part. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.
Referring now to the drawings, a prior art hold-open device is shown in
In
As best shown in
A striker, generally indicated at 30, was suitably secured to the inside of the lowermost door panel 23. As best shown in
As best shown in
When the door is moved to an overhead out-of-the-way position, the edge 40 of the arm would engage the striker inclined portion 33, and would cause the arm to pivot the arm as the door was raised. Finally, the edge would come to the apex between the striker inclined surface and abutment surface, and would then move past. Thereafter, the larger mass of arm portion 38 would cause the arm to pivot in a clockwise direction (as seen in
To release the mechanism, the door was pushed further upwardly, and a force F was applied to the smaller mass portion to cause arm 22 to pivot in a counterclockwise direction such that the striker could then pass by the stop and door could be lowered. This force could be applied by pulling a release cable or lanyard (not shown) downwardly.
Referring now to
In
Hold-open device 50 is shown as broadly including a plate member 62, an arm 63, a striker 64 mounted on one of the door panels, and a pair of springs, severally indicated at 65.
Plate 62 is shown as being a rectangular plate-like member having a plurality of horizontally-spaced vertically-elongated oval-shaped openings, severally indicated at 66. This upper marginal end portion of the plate is adapted to be welded, or otherwise secured, in area contact to the flat vertical side of the track. Thus, the one salient difference between the present arrangement and the prior art arrangement is that the hold-open plate is secured in area contact to the track, whereas in the prior art arrangement, the clevis member was welded to the arcuate bottom of the track. Hence, in the improved device, the area of contact and weldments are greater than in the prior art.
Arm 63 is shown as being a horizontally-elongated rectangular member, one marginal end portion of which is pivotally mounted on the plate. The pivotal connection is indicated at 57. The distal end portion 68 of the arm extends rearwardly toward the cargo access opening 69 (
The arm carries a stop 70 at an intermediate portion of its longitudinal extent. This stop is arranged to selectively engage a striker 64 mounted on the door (
As best shown in
Referring now to
Referring now to
To release the mechanism, an operator need only grasp the release cable or lanyard 81, and pull it downwardly, to cause the arm to rotate in a clockwise direction about pivot point 57. Once the stop is beneath the striker, the door may be moved downwardly to its access-closing position. It should be noted that in the improved embodiment, the release lanyard is physically located adjacent the rear access opening, so as to facilitate grasping by an operator reaching from outside the door to release the hold-open device. Moreover, the device may be released by pulling the release cord vertically downwardly. This is a significant advantage over prior art devices that required an angled pull.
Moreover, the improved design with positive spring force overcomes interference caused by direct and debris interfering with the pivotal movement of the arm, and gives the mechanism a “quickness” to rapidly snap into the hold-open “engaged” position. As the door is moved upwardly, the arm-mounted stop edge rides up the striker inclined surface. This further displaces the springs and increases the force that urges the arm-mounted stop edge to snap into engagement with the striker abutment surface once the door has been moved past the striker.
The present invention contemplates that many changed and modifications may be made. For example, materials of construction are not deemed to be particular critical, and may be changed or varied, as desired. In the improved embodiment, one or more springs may be used. These may be coil springs, as shown, or may be some other type of spring. The particular form of the arm stop is exemplary, and may be changed or modified as desired. While the disclosed embodiment of the hold-open device is described as having been mounted on the track, in a stationary application, such as in a garage or warehouse, the hold-open device could be mounted to some other portion of the static structure. In a vehicular application, the portion of the hold-open device could possibly be mounted on the cargo body, rather than the track. The striker and stop are not limited to these particular forms as shown, but may assume other shapes and configurations as well.
Therefore, while a presently preferred form of the improved hold-open device has been shown and described, and several modifications thereof discussed, persons skilled in this art will readily appreciate the various additional changes and modifications may be made without departing from the spirit of the invention, as defined and differentiated by the following claims.
