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Publication numberUS2746782 A
Publication typeGrant
Publication dateMay 22, 1956
Filing dateMar 2, 1953
Priority dateMar 1, 1952
Publication numberUS 2746782 A, US 2746782A, US-A-2746782, US2746782 A, US2746782A
InventorsJacobus J Schamotta
Original AssigneeImp Cold Storage And Supply Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Releasable door fastening
US 2746782 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

May 22, 1956 J. J. SCHAMOTTA RELEASEABLE DOOR FASTENING Filed March 2, 1953 INVENTOR'.

Schamotta,

ATTO Ills 5 United States Patent RELEASABLE DOOR FASTENING Jacobus 'J. Schamotta, Parktown North, Johannesburg,

Union of South Africa, assignor to Imperial Cold lStorage and Supply Company Limited, Cape Town, Union off South Africa, a corporation of the Union of South A rica Application 'March 2, 1953, Serial No. 339,719

Claims priority, application Union of South Africa March 1, 1952 4 Claims. (Cl. 292-92) This invention relates to releasable door fastenings of the emergency-exit ,type which, having been secured :on the outside of the door, may be released by persons accidentally locked in. Such fastenings are for example used on doors of cold storage rooms.

Known fastening devices of the kind mentioned depend on the undoing of a wing nut on the inside of the door. As the nut is seldom used, a person with numbed fingers and possibly in a panic will have great difficulty in releasing the nut.

An object of the invention is to provide a fastening which can be quickly and easily operated from the inside to unlock the door. A further object of the invention is to provide a fastening which when being released will also act to open the door to some extent to overcome wedging of the door.

A door fastening according to the invention comprises a latch formation adapted to be installed on a door, a keeper formation adapted to be installed on a door post, the latch formation and the keeper formation being arranged to interengage to secure the door on the outside of the door when the keeper formation is held down on the door post, a threaded bush on the keeper formation, a complementarily threaded head, a shaft carrying the threaded head and adapted to pass through the door post and means to turn the shaft on the inside of the door post, the threading being arranged that on turning of the shaft the keeper formation is forced from the door post and out of engagement with the head.

An embodiment of the invention is described hereunder and illustrated in the accompanying drawings, in which:

Figure l is a section through the embodiment in the secured position;

Figure 2 is a view similar to Figure l with the fastening in the unsecured position;

Figure 3 is a section on the line 6--6 of Figure 1 and Figure 4 is an elevation of a rack and pawl mechanism secured on the inside of a door post.

In the embodiment illustrated in Figures 1 to 4 the door 27 is of the conventional wedge type, i. e. the door 27 wedges in the door frame as illustrated next to the door post 28.

An arm 29 secured to the door 27 has a forked end 30 which carries a wing nut 31 which constitutes a latch formation. The nut 31 engages with a hinged bolt 32 in the conventional manner, the bolt being the keeper formation. The base 33 on which the bolt 32 hinges is formed as a thrust block with an internal quick screw threating 34. As shown in Figure 3 the block 33 is keyed against rotation by means of two keys 35 fixed to the post 28.

A shaft 39 passes through the post 28. At the outer end 36 the shaft carries a threaded head 37, the threading on which is complemental to the threading 34. At the inner end 38 the shaft 39 is secured to a lever 40 ice which has a spring pressed pawl 41 and a rack 42 secured to the door post 28. The rack includes a series of in dentations 43 into which the pawl enters under the action of its spring when the lever is moved and which prevent movement of the lever under the action of gravity alone.

As the threading 34 is at 45 degrees, it will be seen that by turning the lever 40 through degrees from the position shown in Figure 1 to the position shown in Figure 2 the head 37 rotates and thus forces the block 33 away from the door post 28. The door securing means will be released and the door forced open by one and the same action. Thus if a person is trapped inside the door 27 and the door becomes stuck for example by being iced up, the trapped person will be able to release the door fastening and to unwedge the door, simply by turning the lever 40.

While one embodiment of this invention has been shown and'described, it will be apparent that numerous modifications and variations thereof may be made without departing from the underlying principles of the invention. It is therefore desired by the following claims to include within the scope of the invention all such variations and modifications by which substantially the results of this invention may be obtained through the use of substantially the same or equivalent means.

I claim:

1. A releasable door fastening of the emergency exit type comprising a latch formation adapted to be installed on a door, a keeper formation adapted to be installed on a door post, the latch formation and the keeper formation being arranged to interengage to secure the door on the outside of the door when the keeper formation is held down on the door post, a threaded bush on the keeper formation, a complementarily threaded head, a shaft carrying the threaded head and adapted to pass through the door post and means to turn the shaft on the inside of the door post, the threading being arranged that on turning of the shaft the keeper formation is forced from the door post and out of engagement with the head, and the latch and keeper being adapted so to interengage that during displacement of the keeper the latch is displaced to move the door outwardly from the door post.

2. A releasable door fastening of the emergency exit type comprising a latch formation adapted to be installed on a door, a keeper formation adapted to be installed on a door post, the latch formation and the keeper formation being arranged to interengage to secure the door on the outside of the door when the keeper formation is held down on the door post, a quick threaded bush on the keeper formation, a complementarily quick threaded head, the bush and head being adapted to interengage, a shaft carrying the threaded head and adapted to pass through the door post and means to turn the shaft on the inside of the door post including a lever adapted to be secured to the shaft, a spring pressed pawl associated with the lever and a rack mechanism adapted to be secured to the door post, the pawl and rack being adapted to engage each other to secure the lever in any desired position on the rack, the quick thread being arranged that on turning of the shaft the keeper formation is forced from the door post and out of engagement with the head, and the latch and keeper adapted so to interengage that during displacement of the keeper the latch is displaced to move the door outwardly from the door post.

3. A releasable door fastening of the emergency exit type comprising a latch formation adapted to be installed on a door, a keeper formation adapted to be installed on a door post, the latch formation and the keeper formation being arranged to interengage to secure the door on the outside of the door when the keeper forma- 3 tion is held down on the door post, a threaded bush on the keeper formation, a complementarily threaded head, a shaft carrying the threaded head and adapted to pass through the door post and means to turn the shaft on the inside of the door post including a lever adapted to be secured to the shaft, a spring pressed pawl associated with the lever and a rack mechanism adapted to be secured to the door post, the pawl and rack mechanism being adapted to engage each other to secure the lever in any desired position on the rack, the threaded head and bush being arranged for interengagement so that on turning of the shaft the keeper formation is forced from the door post and out of engagement with the head, and the latch and keeper being adapted so to interengage that during displacement of the keeper the latch is displaced to move the door outwardly from the door post.

4. A releasable door fastening of the emergency exit type comprising a latch formation adapted to be installed on a door, a keeper formation adapted to be installed on a door post, the latch formation and the keeper formation being arranged to interengage to secure the door on the outside of the door when the keeper formation is held down on the door post, the keeper being adapted to be releasably secured to a shaft arranged to pass through the door post and means to turn the shaft on the inside of the door post, the connection between keeper and shaft being such that when the shaft is turned the keeper is forced from the door post and out of engagement with the shaft, and the latch and keeper being adapted so to interengage that during displacement of the keeper the latch is displaced to move the door outwardly from the door post.

References Cited in the file of this patent UNITED STATES PATENTS 381,740 Wollensak Apr. 24, 1888 1,615,300 Cantrell Jan. 25, 1927 1,919,501 Colvin July 25, 1933 2,461,426 King Feb. 8, 1949 2,473,205 Jazwieck June 14, 1949 2,636,767 Groeger Apr. 28, 1953

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US381740 *Apr 24, 1888 Lever latch and handle
US1615300 *Nov 3, 1922Jan 25, 1927J T Cantrell & CompanyTailboard fastener
US1919501 *Sep 4, 1931Jul 25, 1933Metal Glass Products CoContainer
US2461426 *Feb 10, 1947Feb 8, 1949King Vernon MertonSafety strike plate and release bar
US2473205 *Nov 13, 1947Jun 14, 1949Joseph J JazwieckFire escape control mechanism
US2636767 *Jun 23, 1948Apr 28, 1953Kason Hardware CorpReleasable strike mechanism
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2835487 *May 16, 1956May 20, 1958Clark Henry BEmergency mechanism for unlocking cold storage door and the like
US4211442 *Jan 8, 1979Jul 8, 1980Hansen John DLock strike
US4431220 *Jul 2, 1981Feb 14, 1984Loughlin Robert WSafety release for bar lock
US4884368 *Jan 10, 1989Dec 5, 1989The Marconi Company LimitedMeans for forcing apart two structural members of a closure arrangement
US5026100 *Sep 19, 1989Jun 25, 1991General Dynamics CorporationLock release apparatus
US5104070 *Jun 1, 1989Apr 14, 1992Space Industries, Inc.Structural latch for vehicle coupling mechanisms
US6347485 *Jul 28, 1999Feb 19, 2002Thomas J. HebdaPower assist for moving a door between a closed and an ajar position
US7048312 *Sep 6, 2002May 23, 2006Rational AgSafety mechanism for walk-in interiors, particularly for cooking devices
US8136851 *Jan 22, 2009Mar 20, 2012Babcock & Wilcox Power Generation Group, Inc.Access door with inside latch release
US20030047949 *Sep 6, 2002Mar 13, 2003Hubert BrunnerSafety mechanism for walk-in interiors, particularly for cooking devices
US20100181781 *Jan 22, 2009Jul 22, 2010Nelson Norman DAccess Door With Inside Latch Release
WO1992018384A1 *Apr 22, 1991Oct 29, 1992Space Industries, Inc.Structural latch for vehicle coupling mechanisms
WO2001009467A1 *Jul 26, 2000Feb 8, 2001Hebda Thomas JPower assist for moving a door between a closed position and an ajar position
Classifications
U.S. Classification292/92, 292/340, 292/DIG.650, 49/276, 292/251, 292/DIG.710
International ClassificationE05B63/24
Cooperative ClassificationY10S292/65, E05B63/246, Y10S292/71
European ClassificationE05B63/24C2