Safety device for sliding doors

[57] ABSTRACT

This disclosure relates to a safety stop for vertically movable doors in which a stopping member automatically extends whenever the door is raised, and which is retracted when the mechanism is retracted to a rest position prior to the closing of the door and then is reset as the door is closed so as to be in a position to again extend as a stop when the door is opened.

Claims, 11 Drawing Figures

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3,894,761

SAFETY DEVICE FOR SLIDING DOORS

This invention relates to a door stop and more particularly relates to a safety device for limiting downward movement of vertically closable doors.

In many instances, access doors such as those of garages, furnaces, etc., more vertically to expose an opening and some environment therebehind. The present invention is intended to prevent sudden closing of such overhead doors due to any cause, such as failure of their holding mechanisms (which may be springs, hydraulic or pneumatic lifters) and/or flyback of such doors when they are opened. The present invention provides a mechanism in which a stopping member is automatically extended to prevent descent of a door beyond a predetermined point, once it has been upwardly opened.

The mechanism embodying the invention is further arranged so that the stopping member may be moved to a reset position prior to closing the door and further includes a mechanism which is activated upon closure of the door to place the stopping member in a ready position so it will automatically extend into the path of the travel of the door when it is again raised.

An object of this invention is to provide a new and improved safety device to prevent undesired closure of overhead doors.

Another object of this invention is to provide a device of the type described in which a stopping member automatically is extended into the path of travel of a vertical movable door when it is opened.

A further object of the invention is to provide a device of the type described which is easily reset from a stopping position and which is automatically moved to a ready position upon closing of the door.

The features of the invention which are believed to be novel are set forth with particularity and distinctly claimed in the concluding portion of this specification. The invention, however, both as to its operation and organization, together with further objects and advantages thereof, may best be appreciated by reference to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is a front elevation of a structure having a vertically movable door;

FIG. 2 is a view seen in the plane of lines 2—2 of FIG. 1;

FIG. 3 is a view seen in the plane of lines 3—3 of FIG. 1 with a portion of the cover plate cut away;

FIG. 4 is a side view of the device of FIG. 3;

FIG. 5 is a view of the mechanism shown in FIG. 3 as it is being reset to an operative position;

FIG. 6 is a view of the device of FIGS. 3 and 5 as it is reset;

FIG. 7 is a view of an element used in the mechanism of FIGS. 3-6;

FIG. 8 is a view similar to FIG. 3 showing an alternative form of mechanism, in locking position;

FIG. 9 is a side view of the mechanism shown in FIG. 8;

FIG. 10 is a view of the mechanism of FIG. 8 in position to be reset, the reset position being shown in broken lines; and

FIG. 11 is a detail section on the line 11—11 of FIG 8.

A structure 10 which may be a garage is often provided with a door 11 which moves on vertical rails 12 as by means of a roller 13 rotatably mounted on the door 11.

In accordance with the invention, the door stop mechanism 14 is mounted on the door jamb 15 or in another position in proximity to the door 11 so that it may prevent undesired downward movement thereof. The mechanism 14 comprises a housing having a back plate 16 and a front plate 17 in substantially parallel spaced relation. This housing 14α is attached to the jamb 15 as by screws, bolts, etc. Pivotally mounted to a pin 18 carried between plates 16 and 17 is an Lshaped stopping member 19 having legs 20 and 21. Member 19 is pivoted about pin 18 adjacent the lower end of leg 20. Leg 21 is adapted to extend into the path of the door 11 and carriers a roller 22 at the end thereof for reasons hereinafter made apparent. A second L-shaped lever 23 having legs 24 and 25 is pivotally mounted about a pin 26 carried between plates 16 and 17. Lever 23 is mounted adjacent its upper end in the leg 24 to pin 26. The function of lever 23 as will hereinafter be made apparent is to sense the closing of door 11 and move the stopping member 19 to an operative ready position. A coil spring 27 has arms 27α and 27b which are connected to levers 19 and 23 at pins 29 and 30, respectively.

In FIG. 3, the levers 19 and 23 are shown in full line in the position where lever 19 is in a set position to act as a stopping member and in broken line where lever 23 is in a reset condition.

A lever member 23, as more clearly shown in FIG. 7, is pivotally mounted about a pin 33 between plates 16 and 17 and has legs 34 and 35 arranged to engage lever 19 at flange 36 and lever 23 at flange 37 (FIG. 5), for purposes hereinafter described.

A heavy pin or abutment member 38 is carried between plates 16 and 17 to limit rotational movement of lever 19, and more particularly leg 21 thereof to hold leg 21 in a door stopping position. A handle 40 carried on lever 19 extends through an arcuate slot 41 in plate 17. Handle 40 is utilized to reset the mechanism to the position shown in broken line in FIG. 3.

In the stable positions of the levers as shown in full line in FIG. 3, spring 27 tends to urge the Ivers 19 and 23 in opposite directions of rotation. Pin 38 limits rotation of lever 19 at leg 21, and member 32 at leg 35 limits rotation of lever 23 at flange 36. Upon relative rotation of the two levers, legs 27α and 27b of spring 27 are drawn towards each other, spring 27 is tensioned and has energy stored therein. When the energy is released, it will act to snap one of the levers away from the other.

Assume that lever 19 is in the position shown in FIG. 3, and the door 11 is to be closed. The door 11, if in contact with leg 21, is raised slightly and lever 19 is rotated counterclockwise about pin 18 by means of handle 40. As lever 19 is rotated to the position shown in broken line, it begins to tension spring 27, and then engages leg 34 of member 32. As member 32 is rotated, leg 35 thereof commences to pivot lever 23 counterclockwise about pin 26. The energy stored in spring 27 may now be released to snap lever 23 to the position shown in broken line.

Leg 25 of the lever 23 now extends as shown in broken line in FIG. 3, and the mechanism is in one of its stable states.

When door 11 is closed by downward movement as shown in FIG. 5, it will strike arm 25 of lever 32 and rotate it clockwise around its pivot 26. This tensions

3,894,761 spring 27, and lever 32 then engages lever 23 at leg 35 thereof. Leg 34 of lever 32 then urges lever 19 clockwise and the energy in spring 27 starts to release and snap lever 19 to the position shown in FIG. 6. At this point spring 27 is still tensioned and is ready to snap the lever to the position shown in FIG. 3 when door 11 is raised.

The mechanism may be regarded as having two stable states. One state which may be referred to as a set state is when lever 19 is in a blocking position as shown in FIG. 3. The other or reset state is when lever 23 is moved to the reset position indicated in broken lines in FIG. 3.

The mechanism will always be in one of these two states, except when in a ready position as exemplified in FIG. 6, when spring 27 is tensioned and ready to snap leg 21 of lever 19 into the path of door 11.

A somewhat simplified modification of the mechanism is shown in FIGS. 8-11 wherein the functions of the two levers 19 and 23 are combined in a single lever 50, pivoted at 51 in a housing 52 (similar to the housing 14α of FIGS. 1-7). The lever 50 has a reset leg 53 and a stop leg 54, shaped to have an included angle of about 135°.

In the stop position (FIG. 8) the leg 54 projects into the path of the door 11' and its lower edge rests against a pin 55, corresponding to pin 38. In the reset position (FIG. 10) the reset leg 53 projects into the path of the door and the upper edge of said leg rests against the bottom of the pin 55, the stop leg 54 having been turned to a position where it projects inward and upward and is inactive.

The lever 50 is urged toward either of the positions just described by a spring mechanism which includes a rod 56 pivoted to a stud 57 on the “elbow” of the lever 50, midway between the levers 53 and 54, the rod passing loosely through a hole 58 in the fixed clip 59. The rod carries a coil spring 60 under compression between the clip 59 and a washer 61 fixed on the rod near its pivoted end. A release cord 62 is secured to the stud 57, as by the eyelet 63, passes through a guide 64 in the housing and offset laterally from and below the pivot 51, then out through the bottom of the housing to a pull ring 65.

When the mechanism is in the locked position of FIG. 8 the stop leg 54 is held in place by the force of the spring 60, acting on a line which passes above the pivot 51. To release the lock, the door 11' is raised slightly. The cord 62 is pulled to compress the spring and rock the lever 50 counterclockwise around its pivot. After the line of force of the spring has passed the line from clip 59 to pivot 51 (on which line the spring compression is maximum) it will expand and urge the reset leg 53 of the lever to the position shown in full lines in FIG. 10. As the unlocked door is lowered, its edge pushes downward the relatively unresisting reset leg 53, moving it far enough to rock the lever 50 past the dead-center position of the spring, and permitting the spring to drive the end of the stop leg 54 against the door, as shown in broken lines in FIG. 10. The face of the stop leg is smoothly rounded as indi cated at 66 (or may bear a roller as shown at 22 in FIGS. 3 - 6) so that the door can move easily up and down without binding on the stop leg, and the locking mechanism thus remains in a neutral position until the door is opened (lifted) far enough to permit the leg 54 to drop into the stop position of FIG. 8.

It may thus be seen that the objects set forth above as well as those made apparent from the preceding description are efficiently attained. While a preferred embodiment of the invention has been set forth for purposes of disclosure, it is to be understood that other embodiments to the invention as well as modifications to the disclosed embodiment which do not depart from the spirit and scope of the invention may become apparent to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments and modifications of the invention which do not depart from the spirit and scope of the invention.