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Publication numberUS545049 A
Publication typeGrant
Publication dateAug 27, 1895
Filing dateSep 21, 1894
Publication numberUS 545049 A, US 545049A, US-A-545049, US545049 A, US545049A
InventorsKarl Busse
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Karl busse
US 545049 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)


" Patented Aug. 27, 1895.

(No Model.)-




SPECIFICATION forming part Of Letters Patent NO. 545,049, dated. August 2'7, 1895. Application led September 21,1894. Serial No. 523,714- (No model) To a/ZZ whom it may concern:

Be it known that I, KARL Busen, master baker, of Lneburg, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements in Self- Acting Fire- Guards for Air, Light, and Transport Shafts, of which the following is a specification.

The present invention is a contrivance for the self-acting fire-shutter for air, light, and transport shafts of the various stories on outbreak of a tire.

In the accompanying drawings, Figure l is a vertical section through the shaft, (openedg) Fig. 2, a vertical section, (shutg) Fig. 3,a contrivance fixed in working order.

The shaft ais provided with an iron frame b and an iron trap-door e, which, when shut, fits snugly into said frame. Trap-door e is usually, as Fig. l shows, opened. It is fixed in this position by a pair of tongs or pinchers f, which grasp a ring g, xed to the edge of the shaft. Between the cheeks of the tongs f a spiral spring is arranged, which tends to open the tongs. This tendency, however, is frustrated through a silk thread t' wound several times externally around the tongs. The latter leads to the wall downward and is here and there attached to it. The upper cheek of the tongs fis provided at its outer side with a groove. In this lies a wire 7c, which is bent at its upper end around the silk threads and on the outer side leads downward to ren der possible from there a withdrawal of the thread.

Between the opened door and the wall a spiral springl is arranged, which is somewhat compressed through the door. If fire breaks out at a story, the silk thread, as it is carried to and fro in the shaft several times and moreover moistened with some easily-combustible substance, at once takes re and quickly burns up to tongsfat Well known, is 4completely burned without leaving behind any ash, the resistance which kept the spring k up till then in a compressed stretched condition is removed. The tongs f are opened by the influence of spring h, and the trap-door e shuts partly through its own weight and partly through the repulsive action of the spring l. the burningy of the thread is frustrated, the silk thread t can be drawn away by means of wire 7o, and door ein this manner can be made to fall.

Having now described my I claim, a'nd desire to secure ent, is

The combination with a pair of jaws attached to a trap-door, and an eye with which the jaws are normally engaged, of a combustible cord wound about said jaws to hold them in their position of engagement.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

invention, what by Letters Pat- K. Busen.



If in some way or other the top. As silk, as is

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2983343 *Jan 30, 1959May 9, 1961Lyons Robert JManual and automatic releasable lock
US3983599 *Apr 3, 1974Oct 5, 1976Daihatsu Diesel Mfg. Co., Ltd.Temperature actuated keying device for use in an automatic door closing mechanism
Cooperative ClassificationE05Y2800/252, F24F2011/0095