US2355895A - Automatic releasable lock - Google Patents

Description

Aug. 15, 1944.` T, l... RQBERTS AUTOMATIC RELEASABLE LOCK Filed-April 20, 1942 FIG. 4

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Swim/Wto@ 52 THOMAS L. ROBERTS am@ s.

, 5 www Patented Aug. 15, 1944 UNITEDA STATE AUToMA'rIC RELEASABLE Loox ,Thomas L. Rberts, st; Paul, Minn'. Application Apriiz, 1942, serial No. 489,781

A claims. (01.292-78) My invention relates to automatic releasable locks and has for its object to provide a locking ly held in position. Yet, if this holding does not readily yield under impact of an explosion within the oven there may be serious Wrecking of and injury to the oven'itself and even the building and other devices surrounding it.

It is a principal object of my invention therefore, to provide an automatic locking device, which, While it will hold the oven door tight and very secure under normal conditions, yet can yield to permit swinging open of the door when excessive pressure develops from within from any cause, such, for example, as an explosion within the oven.

A further object of my invention is the provision of a lock member mounted to swing on a pivot and having angularly disposed contact surfaces such that when the door is swung to closing position one of these surfaces will .be engaged by a lxedly positioned catclrmember in such manner that such engaged surfaces will be moved out of its line of movement during closing and the other surfaces will be moved behind the catch member to engage it and hold it in locking position, together with means for exerting spring pressure on the lock member to hold it in either of its adjusted positions.

It is a further object ofA my invention to form a lock member of a multiplicity of plates rigidly united together and to have some of these plates extend rearwardly to form spaced members which may be bent toward each other to form a rough socket and provide a member having a part adapted to enter said socket which may be turned and at the same time has means for holding it in one xed position.

It is a further object of my invention to provide in connection with the aforesaid turnable member a strong spring surrounding it and a follower threaded upon said member so as to engage said spring, said follower being mounted in a channel with straight edged walls, the follower having corresponding walls adapted to engage the channel walls and prevent it from turning.

The full objects and advantages of my inven-Y tion will appear in connection with the detailed description now given in the'appended specification, and the novel features by which the aforesaid advantageous results are obtained are particularly pointed out in the claims.

In the drawing illustrating an application of my invention in one form- Fig. 1 is a plan view of the lock casing in which my invention may be housed.

Fig. 2 is a side elevation of the same.

Fig. 3 is a sectional elevation View taken on line 3-3 of Fig. 1.

' Fig. 4 is a transverse sectional plan view taken on line 4-4 of Fig. 3.

Fig. '5 is an enlarged sectional fragmentary View taken on line 5-5 of Fig. 3.

Fig. 6 is a full face plan View of the lock member dissociated from the other elements of the invention,

As illustrated, a member I0 is adapted to be bolted to a xed oven wall by suitable bolt members passing through bolt holes II and I2. A second member I3 embodies side walls I4 and I5, Fig. 4, spaced apart and having inner plane walls I6 and I'I, which inner walls may be parallel as shown in Fig. 4. The member I3 also has a thickened top Wall I8. Between the side walls I4 and I5 and enclosed by the top Wall I8 is a lock chamber I9 which is open at its face 2U as indicated in Figs. 4 and 5.

The member I0 fast on the oven wall is provided with a thick Wall projecting portion 2|, Figs. 1 and 3, having therein a transverse cavity 22, Fig.3, which is open at its ends as indicated at 23 and 24, and whichalso is open along its extent fronting member I3 as indicated at 25, Fig. 3. When the parts are attached to a fixed furnace wall and a wallA of the oven door is in closed locking position, as in Fig. 3, the open end 20 of chamber I9 and the open end 25 of chamber 22 will be in juxtaposed position so as to form one continuous substantially enclosed chamber.

Extending between the sides of the wall 2| is a strong shaft or pin 26 upon which is mounted a roller 2l. This roller is adapted to be engaged by one or the other of a pair of faces 28 and 29 on a lock member 30; This lock member is formed of a multiplicity of sheet metal plates 3|, 32 and 33, as clearly shown in Figs. 4 and 5'. These metal plates are securely held togetherby suitable means, preferably by strong rivets 34 and 35, Fig. 3, extending through openings 36 and 31, Fig. 6. Any number of such plates may ing into a'threaded opening 42 across shaft 4| is a set screw 44 which has its head 43 of such diameter as just to t between the walls 45 and 45 of the cut-out space 39. By meansof Athis set screw the rocking lock member 30 is held in a fixed position both axially and longitudinally on the shaft 4|.

The plates 3| and 32 are turned toward eachf other as indicated at 41 and 48 of Figs. 4 and 5,

and the plates 33 are semi-circularly cut out, as indicated at 40 of Fig. 3. taken. in conjunction with the turnedin'portions 38 o'f plates 3| and 32 produces a flat-sided socket 50, Fign'. In this socket' 50 is a head 5| fast on aV bolt member 52 threaded at 53 adjacent the head1` 5|, and formed with a screw driver slot 54 on its outer end, Fig. 3. .The head is spherical except,"as best shown in Fig. .'5, where it is provided with oppositely-disposed flat faces 55 and-55. VThe rounded end of head 5| tthrusts A against the curved bottom of cavity 50, as shown at 5l in Fig. 4, and the outer end of bolt member 52 protrudes through an opening 58 in the rear end wall 59 enclosing chamber I9 of lock member i3.

On the threaded portion v53 of bolt member 52 is threaded a followernut 6i), the walls of which are in close proximity with walls I5 and |'|Y of the chamber |9 in'main lock casing I3. The head 5| in the cavity 5E) is restrained from pulling out by reason of the fact the oppositeV faces-.of bent-in'po`rtions 33 of plates v3| and 32 forming the side walls ofl socket 55 prevent it; It :follows that when the bolt 52 is `turned inleitherv direction. the follower nut 6E! will be caused to travel along the bolt either to put more or less compression on a heavy spring 5| surrounding bolt 52 and extending between the;

inner wall of end 59 and follower 53, as shown in Fig. 3. i

Although the bolt 52 is Ythus permitted to turn for adjusting the compression of spring "5i, which is absolutely essential for :the purpose of my invention, the bolt must not be free to turn excepting when itis intended to be turned-that is, the closing and opening of the door and the consequent swinging of lock member 3|) upon its supporting bolt 4|) must not automatically turn or vpermit the turning of the bolt 52, which, be cause the spring 5| constantly urges the follower 60 toward the head 5|, would normally tend to move the follower toward the head to loosen the hold of the lock nut; This might continue to a point where the door would not remain closed against normal internal pressure in the oven.

Thearrangement above described ofthe flattened head 5| `in the socket 50 enables the bolt 52 to be turnedto any desired degree, and when the turning is finished the faces 55 and56 of the head 5| will snap against the faces of the turned-in portions 38 of plates 3l and 32 and hold the bolt against turning.

This cut-out portion The fact that the plates 3| and 32 and the bent extensions 38 thereof are of sheet steel with a normal ability to swing or yield is one of the things which makes the above operation possi- 5 ble.

I claim:

1. A releasable lock comprising a swinging lockmember formed of a series of sheet metal plates shaped and secured together to form a socket having a plane face, a spring-pressed member having a head in said socket engaged'by said face with a yielding pressure, means for forcibly rotating said member against said pressure, and means on the head engageable with said face in one position of rotation of the head to hold the spring-pressed member against turning in the normal operation of the lock.

2.' A releasable lock comprising a swinging lock member formed of a series of sheet metal plates shaped and secured together to form a socket having a pair of plane faces, a rotatable vspringpressed member having a Yhead insaid socket, and means on the head for engaging the walls of the socket normally to hold the member against turning.

3. A releasable lock comprising a swinging lock member formed of a series of sheetvmetal plates shaped and secured together to form a socket having a pair of oppositely disposed plane Vfaces, a spring-pressed member having a head in said socket located between and engaged by said v faces with a yielding pressure, means for forcibly rotating said member against said pressure,` and means on the head engageable with saidffaoes 3Min one position of rotation of the head to hold` the spring-pressed member againstV turning in the normal operation of the lock. `v

4. A releasable lock comprising a swinging lock member formed 0f a series of sheet` metal plates Vligjshaped and secured together to form a socket lhaving a pair of oppositely disposed plane faces, a spring-pressed member having a head in said socket located between and engaged by said faces with a yielding pressure, means for forciblyfro- -lfftatin-g said member against said pressure, and a pair of flat faces on opposite sides of the head, each engageable with one of said faces in one position of rotation of the head to hold the spring-pressed member against turning in the tnormal operation of the lock.

5. A releasable lock comprising a lock casing having a parallel-walled chamber, a lock member having two contact faces, means mounting said lock member to swing between the walls of said schamber, a socket on said lock member having- @0r-otherwise rotatable by force within said socket,

a follower on said threaded member engageable with the walls of the chamber and adapted toy swing with the lock member past dead center of the point of pivot of the lock member to hold 'the same in fixed position on either side of said pivot, a spring engaging said follower to cause the same through the threaded bolt in the socket to exert force upon the follower, said follower and the faces on said head permitting said swing- .ing motion within the parallel-walled chamber,

THOMAS L. ROBERTS.

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