US 1938978 A
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Description (OCR text may contain errors)
De.12,1933. i Ams, I --1,93s,97s
DDOR CONTROLLING MEANS Filed- July 14, 1930 BY y "QV/M A 'ToRNEYs.
Patented Dec. l12, 193.3
, UNITED STATES DOOR CONTROLLING MEANS Albert Rush, Columbus, Ohio; Frank A. Hunter and Ruby B. Rush,
Albert Rush, deceased administrators of said' Application July 14, 1930. Serial No. 467,694
5 Claims. (Cl. 20-20) My invention pertains to door controlling means and is particularly related -to that type of door which is designed to be maintained in open position by resilient means or similar devices that may be readily overbalanced to elect closing of the door. It is particularly applicable to fire doors but is not lnecessarily limited thereto.
In the prior art, it has been customary to provide doors of this type with resilient -controlling means designed to be entirely ineffective under certain conditions so that the door will close of its own weight. For example, it has been the practice to provide fire doors with controlling springs connected thereto by cables having links fusible in the event of certain high temperature conditions to entirely release the door from restraint and permit it to descend into closed position of its own weight. With devices of this nature, the shock of closing is extremely severe and the consequent wear and tear upon the door is undesirably great.
One of the objects of my invention is to provide a controlling means for a door which will be effective to adequately balance the door in open position by means of a tension spring but which may permit automatic closing of the door without the shock and jar usually attending such automatic closing in doors of this type. Other objects will appear as this description progresses.
My invention is particularly applicable to doors slidable into and out of closed position, although it is not necessarily limited thereto. In preferred form, it comprises a resilient unit, such as an eX- tension spring, which is sc connected to the sliding door that it will hold this door in raised open position Whenever the door has been moved to such position, until it is temporarily rendered ineiective. A fusible link or, under certain conditions, a manually operable means may be used to temporarily render the resilient means ineffective until the door has been well started on its movement into closing position. However, the structure is preferably such that the resilient means will reassume control of the door during the termination of its closing movement and will, while permitting completion of the closing movement, cushion such movement so as to eliminate all undesirable shocks and jar.
The extension spring which I preferably utilize is that type of coil-spring which is wound with an initial tension greater than the subsequent tension arising from the extension thereof. Furthermore, this initial tension is especially selected so that it will immediately offset the extra impetus given to my door by its initial travel without restraint from the spring. The initial tension is denitely selected to suiliciently absorb and counteract the shock of the impetus of the door to ensure that this door will finally move into closed position easily and substantially withoutjar.
The preferred embodiment of my invention is shown in the accompanying drawing wherein similar characters of reference designate corresponding parts and wherein:
Figure 1 is a perspective view, partially broken away, illustrating my preferred form of door controlling means in application to a sliding door.
Figure 2 is a side elevation of a door with my invention applied thereto.
' Figure 3 is a front elevation of a sliding door with my invention applied thereto, the door being shown in raised position.
Figure 4 is a front elevation of the structure shown in Figure 3 with the door shown well on its way into closed position.
In ihe drawing, my invention is shown applied to a sliding fire door 1 which is constructed of a plurality of sections hinged together. This door is provided along its longitudinal edges with .a plurality of rollers 2 which operate in tracks 3 disposed on both sides of the doorway in a well known manner. 4
In the main, the door moves into and out of closed position with a sliding movement, being disposed parallel with the vertical track portions when closed and parallel with the horizontal track portions when opened. The principal deviation from this sliding movement is had by the upper section or panel of the door which is caused to move into and out of closed position with a swinging as well as a sliding movement. The structure for accomplishing this will only be briefly described, inasmuch as the invention to which this application is directed has no necessary relation thereto and may be applied to doors entirely lacking this feature.
With relation to this feature, it will suffice to say that the upper section of the door carries, at each corner thereof, a fork-like member 4 pivoted at 5 to the door section and having a roller 6 intermediate its end forcooperation with the track 3. The forked end of each member 4 is movable with the closing of the door into embracing relation with a pin 7 of a bracket 8 mounted adjacent the arcuate portion of the track and, thereupon, the members 4 swing about the pin 7 to swing and force the upper section of the door into final closed position. l
The door is counterbalanced by means comprising cables 9 and 10 which are preferably connected to the lower section or panel thereof. The cable 9 extends from its point `of connection to the door upwardly over a sheave 11 and' thence over a sheave 12 and then over one unit of a double pulley 13. The cable 10, after connection tothe door, extends upwardly and around a sheave 14 and thence over another unit of the pulley 13. The ends'of these cables 9 and 10 are connected as at 15 and 16 to a bracket 17.
The pulley 13 is carried by one end of a coil this coil spring is connected to a slotted member 19 which is eccentrically pivoted as at 20 to a bracket 21. This member 19 is normally held in the upright position in which it is shown in Figure 3 of the drawing by means of a cable 22 connected to a lug 23 on the member 19. This cable 22 extends around a sheave 24 and has its free end extended across the upper end of the door and connected to theupstanding angle iron 25 as at 26. It will be noted that a fusible link 27 is disposed intermediae the length of the cable 22 and, to all intents and purposes, forms a part thereof.
The extension spring 18 which I preferably utilize for ultimately restraining and cushioning'the movement of the door into closed position is that type of spring wherein the initial tension is greater than the subsequent tension. For example, with a certain weight of door, the spring should be so wound that it would balance a load equal to, say thirty pounds. the second inch stretch would equal a load of thirty-six pounds, the third inch forty-two pounds, and so on. Thus, the door moving under the impetus of the initial release will be firstl caught and restrained by the high initial tension of the spring and this will be effective to slow up the movement of the door sufciently to ensure that it will move into closed position easily.
This type of spring is peculiarly desirable with my controlling means and it will be understood that the spring is especially designed to have an initial tension which is adequate to practically reduce the speed of movement of the dropping door shortly after the restraining action oi the spring is imposed upon the door to such an extent that subsequent downward movement of the door is merely adequate to effect a gentle closing thereof.
In operation, the normal position of the parts when the door is open is illustrated in Figure 3. In the event of the generation of a sufficiently intense heat in proximity to the door to melt the fusible link 27, the cable 22 will separate as indicated in Figures 1 and 4 and the pivoted member 19 will be permitted to drop down to the position shown in these figures. This will reduce the tension upon the coil spring 18 to a sufficient extent to permit the door 1 to automatically start to move downwardly towards closed position. It should be noted in this connection that, when the pivoted member 19' drops down tothe position illustrated in Figures 1 and 4, the end of the spring which is connected thereto will slide along the slot to the outer end thereof and the samey line of pull of the spring will be maintained. Once this overbalanced condition has been created, the door will continue the move downwardly until it finally closes. However, during this downward movement,A the coil spring in its new position will exert suflicient. resistance to the downward movement of the door to ensure that this door will move intol its closed position without shock or jar. When it is again desirable to maintain the door in 'its open and counterbalanced posi tion, it will merely be necessary to raise the door to fully open position, and join the parts of the cable 22 by a lfusible link of sufficient length to maintain the member 19 in upright position. At this time, the raising of the member 19 to upspring 18 which is in tension. The other end of right position has increased the tension upon the spring 18 sufficiently to ensure that the door will remain eounterbalanced in open position.
It will be understood that my door controlling means may be utilized in connection with doors other than fire doors and is not necessarily limited to sliding doors. For example, it may be desirable to release the member 19 to decrease the effectiveness of the spring 18 by means of a lever or a push button of some kind, so that the door may thus be set free to initiate its movement towards closed position by its own weight while its final movement into closed position will be cushioned by adequate resilient means. Likewise, other means may be used for bringing about the automatic initiation of movement of the door towards closed position or for nal cushioning of thev movement of said door into closed position.
Having thus described my invention, what I claim is:
1. Door controlling means comprising a spring for counterbalancing a door when in open position, a pivoted member to which one end of said spring is connected, and means for effecting adjustment of said pivoted member to temporarily decrease the resistance of said spring, said means being subsequently effective to render said resistance more effective.
2. Door controlling means comprising a spring for counterbalancing a door when in open position, a pivoted member to which one end qf said spring is connected, said pivoted member being adjustable to different positions to provide different resistance of said spring at different stages of operation, and a cable having a fusible link therein and connected to said member for maintaining said spring at full tension.
3. Door controlling means comprising a spring for counterbalancing a door when in open position, a pivoted member having a slot therein within which one end of said spring is connected, said pivoted member being adjustable to different positions to vary the tension of said spring, said spring being so connected in the slot of said pivoted member that it may slide along the slot.
4. Door controlling means comprising a door, a spring operatively connected to said door, means in association with said spring for maintaining the spring under tension sufiicient to counterbalance the door when in open position, and means for decreasing the tension of the spring to an extent sufiicient to permit the initiation of the closing action of the door and after the closing action hasbeen initiated to exert sufllcient resistance to the downward movement of the door to ensure the movement of the door into its closed position without shock or jar.
5. Door controlling means comprising a. door, a spring operatively connected to said door under sutiicient tension to counterbalance the door when in open position, and means in cooperative relation with said spring for decreasing the tension of the spring to an extent suflicient to permit the initiation of the closing action of the door and after lthe closing action has been initiated to exert sufilcient resistance to the down-4 ward movement of the door to ensure the movement of the door into its closed position without shock or jar.