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Publication numberUS1011691 A
Publication typeGrant
Publication dateDec 12, 1911
Filing dateMay 19, 1909
Priority dateMay 19, 1909
Publication numberUS 1011691 A, US 1011691A, US-A-1011691, US1011691 A, US1011691A
InventorsJames G Wilson
Original AssigneeJames G Wilson
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Automatic drop for fire-shutters.
US 1011691 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)



1,011,691. PatentedDec.12,l911.



Specification of Letters Patent.

Patented Dec. 12, 1911.

Application filed May 19, 1909. Serial No. 496,926.

To all whom it may concern..-

Be it known that I, JAMZES G. WILSON, a subject of the King of Great Britain, residing at Larchmont, Westchester county, State of New York, have invented a certain new and useful Improvement in Automatic Drops for Fire-Shutters, of which the following is a specification.

My invention relates to shutters made of fire resistant material and adapted to automatically close over the opening that is to be protected whenever the temperature shall reach a predetermined maximum.

My invention, while applicable to shutters sliding straight away, is preferably used on rolling shutters.

My invention has reference particularly to automatic shutters of the partially counterbalanced type in which the shutter is intended to be always either fully open or fully closed, but which requires only a relatively small force to open from a closed position.

It comprises certain special constructions and arrangements of parts as will more fully appear as the specification proceeds.

The object of my invention is to provide a means by which, in case of fire, the shutter may be released and closed automatically, positively and certainly without risk of failure, and without entailing damage to structural and functional parts of the curtain.

A further object is to enable the shutter to be quickly and easily reset in operative position without the aid of special tools and labor.

A still further object of my invention is to enable the shutter to be released (and to then close itself) at will at any time without substantial efiort.

Still further objects of my invention will hereafter appear. v

Referring to the drawings hereto annexed, which form part of-this specification, Figure 1 is a rear elevation of a coiled shutter of the class described with my invention applied thereto, the shutter being broken and shortened through its middle and also broken away below to save room; Fig. 2 is a greatly enlarged view of part of the left hand side of Fig. 1, being drawn thus large to more perfectly bring out some of the essential and operative details; and Fig. 3 is a detail partly in diagram, illustrating a modified mode of releasing the shutter at will.

Briefly, the embodiment of my invention 1s as follows The shutter is arranged in any usual way to be nearly in balance, 2'. 6.,

so that it always tends to close itself but only of said shutter, and capable of being released by hand so as to permit the shutter to drop and close. Other spring devices are held in non-operative position by fusible link means. When such last named means is melted by reason of the predetermined temperature being reached,

these latter named spring devices are set free and press downwardly upon the bottom bar of the shutter with a force which added to the normal downward tendency of said shutter is sufficient to overcome the first named spring retaining means; the shutter will then drop and close its opening. To reset the shutter, it is only necessary to lift it with the small force required to make up the counterbalance until it passes above the first named spring retaining means, the last named spring devices having first been drawn to non-operative position and a new fusible link being placed to hold them in said position.

In detail, A is a metallic shutter of any usual construction; it is shown open and coiled in a casing A over the opening to be protected. The arrangement of drum or drums upon which the shutter is coiled may be any of those usual and well known in the art in which springs of some kind may be set to exert a tendency to efiect said coiling. By suitable adjustment, these springs may be set so that the downward pressure exerted by the bottom bar B when in the position shown (shutter open) will be any desired amount; in the application of my invention I prefer that this should be about 10 pounds. v H

At each end of the bottom bar B is a bell crank locking lever C pivoted to the shutter frame at D. One arm a of this bell crank extends horizontally and has attached to it a freely hanging wire rope or chain E the other arm 6 being inclined slightly toward the center of the shutter and provided with an inner, downwardly and centrally inclined face F and an upturned extension or tongue G; springs II suitably determined as to tension, press against said tongues G, maintaining them against stops I. These springs II are given such dimensions and qualities as enable the two of them to just retain the shutter bar B in the position shown, against the downward pressure chosen.

To release and close the shutter at any time, one need merely pull down upon one or the other of the chains, E; this will throw the duty of resisting the downward tendency of the shutter upon one only of the bell cranks C, and this duty it will be unable to fulfil so that the upwardly extending arm Z) will be forced outwardly against the pressure of spring H and the shutter will drop.

The shutter being open as shown in the drawings, I apply my automatic release, to be effected by the predetermined dangerous rise of temperature as follows :-At each side of the shutter and attached to the frame thereof, I place a pressure lever J extending inwardly so as to have its inner end directly over the shutter bar or an extension K at tached thereto. Each pressure lever J is free to move pivotally upon a central spindle capped with a screw L, which holds the lever in position. This spindle is itself axially rotatable as to box M, being journaled therein at top and bottom. Fixed to the spindle and outside of the box is a toothed head M and within the box is a coil spring M the inner end of which is fastened to the spindle. The outer end of this spring is fastened at M to the peripheral casing of box M. Attached to the under side of lever J is a dog M pivoted to the lever at M so as to be capable of engaging the aforesaid head M as shown in Fig. 2. In the use of my invention I so arrange that the coil spring h 2 tends to exert a determined amount of downward pressure on lever J. I may adjust the magnitude of this pressure after the curtain is set by grasping the head M with any suitable device and rotating the same counter-clockwise, holding the said head atany point while taking a new grasp thereof by moving the set screw L into one of the notches of the head. Or, before the curtain is set, I may determine the tension of the spring by using lever J to rotate the head M by use of the dog M using L as before to temporarily hold the head in any given position. This arrangement of spring and its relation to the lever is not set forth and claimed as part of my invention, being a device well known in the art.

At the inner end of each lever J, I form a closed loop N bent upwardly and centrally, and through each loop I pass a short wire or chain 0 attached at one end to eyes P and having, at the other end, common attachment to a longer wire or chain which may be positioned above as at Q, or below as at Q. If carried to the upper position, some system of supports with pulleys, rollers or the equivalent for changin direction of the chain as R must be established. In the center of the chain Q or Q, is placed a fusible link S. Should the wire be placed in its upper position as at Q then obviously the fusing temperature determined upon would be lower than that chosen should the wire be in its lower position as at Q, since the temperature always increases as the higher points in the room are approached.

In case of fire or a dangerous rise of temperature the fusible link S is melted and the two short chains 0, O, are slacked thus allowing the springs in M to force the levers J downwardly against the plates K on the bottom bar of the shutter. This downward force added to the downward tendency of the shutter itself will over-power the bell cranks C and press the arms 6 outwardly thus releasing the shutter which will at once drop and close. The release and closure of the shutter by hand through pull on the chain E as previously described is convenient not only in some cases where it is desired to permanently close shutters for the night at the close of each days business, but also in cases of conflagrations of certain types where flying embers and brands are to be feared. In such latter named cases, particularly, burning masses of greater or less size are often hurled through windows into rooms which are thereby set fire to although the temperature at the fusible links of the protected shutter may not have risen appreciably or at all above normal. In such cases Where it can be foreseen, a method of closing all the curtains simultaneously on one side or more sides of the building may be desirable. Such a method is easily applied to my invention by substituting electro-magnetic means for the chain E. One method of accomplishing this is shown in Fig. 3, where the free arm of the bell crank lever C is shaped to constitute an armature a, while suitably positioned to attract this armature when energized is an electromagnet- T. Both armature and magnet should preferably be of one of the usual long pull types. As many shutters as it may be thought best to include in any one group may have their magnet circuits arranged either in parallel from one source of current or they may be placed in series with said source according as conditions and prefer ence may indicate.

Many changes of detail may obviously be made without departing from my invention which is embodied in the following claims.

What I claim is: 4

1. In a fire resistant shutter of the type described, means for engaging the shutter and holding it in open position, a pressure lever for engaging said shutter and forcing it out of engagement with the aforesaid means so as to permit said shutter to fall, and means for actuating said pressure lever.

2. In a fire resistant shutter of the class described, means for engaging the shutter and holding it in open position, and a spring actuated pressure lever arranged to function at a predetermined temperature and adapted to engage said shutter and force it out of engagement with the aforesaid means so as to permit said shutter to fall.

3. In a fire resistant shutter of the type described, means for latching said shutter in open position, a pressure lever functioning at a predetermined temperature adapted to unlatch and permit said shutter to fall, a spring for actuating said lever, and means for adjusting the tension of said spring, substantially as and for the purpose described.

4. In a fire resistant shutter of the type described, a spring controlled latching lever adapted to engage the body of the shutter in open position and a spring actuated pressure lever adapted to function at a predetermined temperature so as to force said shutter out of engagement with the latching lever and permit the shutter to fall, substantially as and for the purpose described.

5. In a fire resistant shutter of the type described, a latching lever adapted to engage the body of the shutter in open position, a pressure lever also adapted to engage the body of the shutter and further to force the shutter out of engagement with the latching lever, and means including a fusible link arranged to normally hold said pressure lever away from the shutter, substantially as and for the purpose described.

In testimony whereof, I have hereunto set my hand in the presence of two subscribing witnesses.




Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3580321 *Apr 25, 1969May 25, 1971Ruskin Mfg CoSmoke damper
US5896907 *Oct 23, 1997Apr 27, 1999Cornell Iron Works, Inc.Rolling fire door including a door hold-open/release system
U.S. Classification160/7, 49/7
Cooperative ClassificationE06B9/82, E05Y2201/41