Fire door operating apparatus

June 20, 1961

Filed July 18, 1960

h. b. clark 2,989,302

FIRE DOOR OPERATING APPARATUS 2 Sheets-Sheet 1

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June 20, 1961

Η. B. CLARK

FIRE DOOR OPERATING APPARATUS

2,989,302

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ATTORNEY

United States Patent Office

2,989,302

Patented June 20, 1961

2,989,302

FIRE DOOR OPERATING APPARATUS Henry B. Clark, 1247 Clinton Place, Elizabeth, N.J.

Filed July 18,1960, Ser. No. 43,527

Claims. (Cl. 268—30)

This invention relates in general to fire doors of the type wherein the door is mounted to slide or roll on a track and is held in open position by a counterweight and a connection between the counterweight and the door including a fusible link so that the heat from any fire in the vicinity of the door will fuse the link and release the door to its closed position. However, in the operation of known doors of this type, the operator, during normal operation of the door, is required to manually pull the door into closed position against the influence of the counterweight, which requires the expenditure of considerable physical energy.

A primary object of the present invention is to provide a novel and improved apparatus including a motor for closing the door, and means to permit the door to close by action of gravity independently of the motor and for disconnecting the door from the motor whenever it is desired, for example, in case a person should be trapped in a room closed by the door and manual opening of the door should become necessary.

Another object is to provide apparatus of this character wherein the door shall be opened by a counterweight connected to the door through a fusible link and which shall include a motor-driven part movable in a pre-determined straight path engageable with a coacting part on the door for motor-closing of the door, and the part on the door shall be manually disengageable from the motor-driven part at the will of the operator and shall be automatically actuated into non-cooperative relation to said motor-driven element in case said element should be stopped intermediate the limits of its travel in said path and the door should be released by fusing of the fusible link under the influence of heat from a fire in the vicinity of the door.

Other objects, advantages and results of the invention will be brought out by the following description in conjunction with the accompanying drawings in which

FIGURE 1 is a front elevation of a fire door operating apparatus embodying the invention, showing the door in closed position in solid lines and in open position in dot and dash lines, and illustrating the motor-driven part and the cooperative door-carried part in cooperative relation to each other;

FIGURE 2 is a fragmentary plan view of the apparatus taken from the plane of the line 2—2 of FIGURE 1;

FIGURE 2A is a fragmentary elevation of the motordriven part and the cooperative part carried by the door, illustrating the parts in non-cooperative relation;

FIGURE 3 is a greatly enlarged fragmentary front elevation of a portion of the door, one of the door hangers and a portion of the track, the motor-driven part for closing the door and the cooperative door-carried part illustrated in cooperative relation by solid lines and in non-cooperative relation in dot and dash lines; and

FIGURE 4 is a side elevation from approximately the plane of the line 4—4 of FIGURE 3.

Specifically describing the illustrated embodiment of the invention, the reference character A designates the wall of a building in which is a door opening B which is closed and opened by a door C. The door is shown as having hanger brackets 1 rigidly secured thereto and projecting upwardly therefrom, which have rollers 2 journaled therein and rollable along a mounting track 3 which is rigidly secured on the wall A by bracket bolts 4 in inclined relation to the door opening B so that the door will normally roll along the track by action of gravity into closed position. Movement of the door into closed and open positions is limited by the usual stops 5 and 5a respectively, that are mounted on the wall and abutted by the edges of the door. The door is actuated into open position by a counterweight 6 which is connected to one end of a cable 7 that passes over an idlersupport pulley 8 and has its other end connected to one end of a fusible link 9, the other end of which is connected to an arm 10 secured to the door. The counterweight is sufficiently heavy to normally roll the door along the track 3 into open position, and in case of fire in the vicinity of the door, with the door open, the fusible link will be disintegrated to disconnect the door from the counterweight whereupon the door will automatically roll by action of gravity into closed position. It will be noted, however, that normally when the door is in open position and it is desired to close the door, in the absence of power-operated apparatus, it would be necessary for the operator to manually pull the door into closed position, and while another counterweight to substantially balance the counterweight 6 might be provided, it would still be necessary for the operator to expend considerable physical energy in simply overcoming the weight of the door for moving the door from open to closed position.

It is the purpose of the invention to provide poweroperated apparatus for relieving the operator of work incident to closing the door, in combination with means for permitting the door to be automatically gravity-closed in case of fire and also to permit the door to be manually opened by a person when desired. While the construction of such apparatus may be widely varied, for the purpose of illustrating the invention, it has been shown as comprising a guide track 11 supported on the wall A in line with the mounting track rail 3, and preferably formed of a tube of rectangular cross section having a longitudinal slot 12 in its bottom wall. Slidable within the guide track and movable from one end to the other thereof is a hollow metal guide block 13. The outside dimensions of the block are smaller than the inside dimensions of the track so that the block has a free sliding contact with the inner walls of the track so as to smoothly guide the block in its movements in the track. Secured to and depending from the bottom Wall of the block and projecting through the slot 12 is a motor-driven part that is shown in the form of a pin or stud 14. The block 13 is moved through a predetermined path along the 'guide track by a flexible chain 15 that has one end secured to one end of the block 13 as indicated at 16 and its other end secured to the other end of the block as indicated at 17. At one end of the guide track, the chain passes over a sprocket wheel 18 and at its other end the chain passes over a sprocket wheel 19 Which is driven so as to move the chain longitudinally upon rotation of the sprocket, it being understood that the two sprockets are journaled in the track 11. The sprocket wheel 19 is operatively connected to a reversible electric motor 21 mounted on a frame 22 secured to the wall A. The exact construction of the driving mechanism is not material to the invention; it may be of the same general nature as that shown in my Patent No. 2,412,871. For a schematic illustration, the motor 21 is shown as having a belt connection 23 with a pulley 24 on a shaft 25, the pulley being associated with a friction clutch. On the shaft 25 is a pinion 26 that meshes with a gear 27 on the shaft of the sprocket 19. The motor may be controlled by a single simple switch (not shown) that may be either manually or automatically operated; and connected in circuit with the motor and the switch may be a magnetic controller for the motor, a selector switch to reverse the motor, and suitable limit switches to stop the operation of the motor

2,989,302 at the limits of the opening and closing movements of the door. Also, desirably, an electromagnetic brake 24ά is associated with the pulley 24 to brake the movements of the parts as they approach their limits of movement. It will be understood by those skilled in the art that the 5 ratio of the driving gears and sprockets will be determined in accordance with the motor speed and the desired speed of movement of the door. With this construction, it will be seen that upon longitudinal movement of the chain in opposite directions, the guide block 13 will be moved back and forth within the guide track 11, and during its movement in one direction, the pin 14 will cooperatively engage a door-carried part 20, that is shown in the form of a latch, for actuating the door into closed position.

The present invention is directed toward the broad combination of the motor-driven part or pin 14 and the cooperative door-carried part or latch 20 which permits normal closing of the door under the power of the motor and also allows the door to close by action of gravity, 20 separate from the motor drive, in case of fire.

The door-carried part or latch 20 is shown as comprising a plate 28 pivotally mounted intermediate its ends on a stud 29 that is rigidly mounted on and projects from a mounting plate 30 which is conveniently 25 secured on one of the door hanger brackets 1 by bolts 31 that project from bars 32 that are disposed on the side of the bracket 1 opposite the plate 30 so that the bracket is clamped between the plate 30 and the bars 32. To steady the plate 30 on the hanger bracket, preferably studs 33 are rigidly secured to the plate and disposed at opposite edges of the hanger bracket 1. The end of the latch plate 28 that extends toward the motordriven pin 14 has a portion thereof turned downwardly as shown at 34 for abutment with the pin 14. The latch plate is mounted intermediate its ends so that the action of gravity on the end portion of the plate opposite the downturned end 34 will tilt the plate so as to normally hold the engaging portion 34 in position to be abutted by the pin 14, movement of the latch plate under the action of gravity being limited by abutment of the plate by a pin 35 on the mounting plate 3ft.

With this construction, it will be observed that normally the motor-driven pin 14 will be in cooperative engaging relation with the door-carried latch 20, and when the door is in open position as shown in FIGURE 1, starting of the motor in one direction will cause movement of the pin 14 in one direction so as to push the door into closed position, while when the door is in closed position as shown in FIGURE 1, reversal of the motor will cause the pin to move in the opposite direction and the door will be closed by gravitational action on the counterweight 6.

To permit disengagement of the latch from the pin 14, a pull cord 36 is connected to the downturned end portion 34 of the latch plate 28 and extends downwardly along one side of the door for a portion of its length and then through an opening 38 in the door and along the other side of the door as indicated at 37. Desirably, hand grip elements 39 and 40 will be connected to the cord at opposite sides of the door, respectively. It will be understood that a simple pull on the cord will move the engaging portion 34 out of cooperative relation to the pin 14 so that the door will be released or disengaged from the motor-operated parts as shown by dot and dash lines in FIGURE 3, and can be opened by the counterweight when the fusible link 9 is intact, or can be manually pushed into open position in case the fusible link is disintegrated. A stop lug 41 on the mounting plate 30 limits swinging of the latch plate 28 under the influence of a pull on the cord 36.

Another feature of the invention is that should the motor-driven pin 14 become stopped or stuck intermediate the limits of its movement with the door in its open position, and in the presence of a fire, the door upon the pivotal mounting of the plate upon movement of the release by the fusible link would be free to move into door from open position to closed position relatively to closed position by action of gravity, the engaging end portion 34 of the latch plate being tilted downwardly by engagement of the pin 14 as shown by dot and dash lines in FIGURE 3 so as to slide freely past the pin and permit the door to freely close. The invention thus ensures against any interference by the motor-operated apparatus with the safe operation of the door in case of fire or in case of entrapment of a person in a room at the side of the door opening opposite the door.

While the invention has been shown as embodied in certain structural details, it will be understood that the construction of the door may be widely modified and changed within the spirit and scope of the invention.