US2790688A - Latch device - Google Patents

Description

April 1957 w. L. S HEPHERDSON 2,790,688

LATCH DEVICE v Filed Oct. 8, 1956 INV EN TOR.

WILLIAM L flit 095E030.

United States Patent 2,790,688 LATCH iiEVICE William L. Shepherdson, Phoenix, Aria assignor of sixtysix and two-thirds percent to J. E. Meacham, Phoenix, Ariz.

Application October 8, 1956, Serial No. 614,697

4 Claims. (Cl. 311104) This invention pertains to an improved latch device particularly adapted to use in conjunction with folding and knock-down furniture and the like.

One of the objects of this invention is to provide a latch device which is simple to manufacture and is highly efficient in operation and maintains its adjustment indefinitely under long and hard use.

Another object is to provide a latch device capable of preloaded locking of the latch in part to maintain a rigid interconnection of the respective parts when latched together by the device.

A further object is to provide a latch device having critically positioned interengaging surfaces on the latch and keeper.

And a further object is to have in the latch device an adjusting means for accurately and securely positioning the interengaging parts of the device.

Further features and advantages of this invention will appear from a detailed description of the drawings in which:

Fig. l is an enlarged view partly in section showing the latch device at the initial stage of latching engagement.

Fig. 2 is a view similar to Fig. 1 showing the latch device at an intermediate stage of engagement.

Fig. 3 is a view similar to Fig. 1 but showing the device just at the point of latching in.

Fig. 4 is a view similar to Fig. l but showing the latching device in fully latch in condition.

Fig. 5 is a plan view of the latching device indicated by the line 5-5 in Fig. 4.

As an example of one embodiment of this invention, there is shown a furniture unit such as a folding chair or table having a top piece and legs 11 suitably carried on supports 12 for rocking about the axis 13 and swing in the arcuate path 14 in a manner such as set forth in my copending patent application Serial No. 591,896 filed June 18, 1956.

The legs 11 are provided with dowel plugs 15 adapted to engage into mating sockets 16 formed in the underside surface 17 of the top piece 10 when the legs are in fully extended position. A stretcher bar 18 is rigidly fixed to the legs and has a surface 19 to which is rigidly fixed the keeper member 20 by suitable screws 21a.

The latch member 21 comprises a base plate 22 rigidly fixed to the underside surface 17 of the top piece 10 by suitable screws 23 and has an upturned end portion 24 in which is formed a slot 25. An adjustable member 26 has a reduced upturned outer end portion 27 extending through the slot 25. At the other end of the member 26 are the upturned side portions 28. spring 29 is located between the surface 30 of the base plate 22 and the surface 31 of the member 26. An adjusting screw 32 passes through a hole 33 in the member 26, through the spring 29 and adjustably threaded at 34 in the top piece 10 so that adjustment of the screw 32 may accurately position the member 26 relative to the keeper member 20 for accurate and positive locking action for the device.

A compression 2,790,688 I Patented Apr. 30, .1957

The latch piece 35 is formed of a fiat strip 36 and a lug piece 37 suitably secured together and having trunnion portions 37a pivotally mounted in holes 38 formed in the upturned side portions 28 of the adjustable member 26. A spring 39 having one end 40 in contact with the top surface 41 of the adjustable member 26 is supported on a transverse pin 42 fixed in the upturned side portions 28, the other end of the spring 39 having an anti-friction roller 43 journaled thereon adapted to rollingly engage the surface 44 of the latch piece 35.

As the legs 11 and stretcher bar 18 move to the left, Fig. l, in opening out the leg assembly of the furniture piece, the outer edge 45 of the keeper member 20 abuttingly engages the arcuate surface 46 of the latch piece 35 swinging the latch piece counter-clockwise, Fig. 2, in opposition to the force exerted by the spring 39 moving the latch piece 35 away from the transverse stop indentations 47 fixed in the upturned side portions 28 of the adjustable member 26. This action continues as the leg member folds outwardly finally bringing the edge 45 of the keeper member 20 to the apex 48 of the arcuate portion 46 of the latch piece 35. Further movement of the leg member, Fig. 4, causes the dowel plugs 15 of the legs 11 to enter the sockets 16 and to bring abutment surface 49 on top of leg 11 into abutting contact with the underside surface 17 of the top piece 10. At this moment the latch piece 35 is snapped by the spring 39 into latch position shown in Fig. 4, with the edge 45 of the keeper member 20 engaging finally in the crotch 50 in the member 35. It is to be noted that the surface 51 radially positioned as indicated by the arrow 52 with regard to the axis 53 of the trunnions 37a for free snapping home of the latch piece as described. Further, the surface 54 of the keeper member 20 is positioned so as to avoid interfering contact with the apex portion of the latch piece when in latch position, Fig. 4, and to permit positive engagement of the keeper and latch at the crotch St) to rigidly hold said stretcher bar and legs 11 with their abutment surface 49 firmly against the underside surface 17 of the top piece 10. Pressure may be exerted manually in the direction of the arrow 55 to swing both the latch piece to release the leg member to be folded up.

While the apparatus herein disclosed and described constitutes a preferred form of the invention, it is also to be understood that the apparatus is capable of mechanical alteration without departing from the spirit of the invention and that such mechanical arrangement and commercial adaptation as fall within the scope of the appendent claims are intended to be included herein.

Having thus fully set forth and described this invention what is claimed and desired to be obtained by United States Letters Patent is:

l. A latch device for two relatively movable members to be disconnectably fastened together comprising a latch piece fixed to one of said relatively movable members having a crotch portion thereon, a keeper member fixed to the other of said relatively movable members having an outer edge adapted to engage in said crotch portion, and a yielding means to normally swing said latch piece toward latching position with said keeper piece to secure said relatively movable members in a predetermined latched position.

2. In a latch device as set forth in claim 1 wherein said latch piece is adjustably positionable relative to said one of said relatively movable members.

3. In a latch device for folding furniture and the like having a top piece and legs interconnected by a stretcher bar, a keeper member fixed on said stretcher bar, a latch member comprising a base plate fixed to said top piece, an adjustable member pivotally mounted by slot and tongue means on said base plate, means for yieldingly urging said adjustable member away from said base plate,

and adjusting screw means opposing said last mentioned means to position said adjustable member relative to said base plate, a lug piece pivotally mounted on said adjustable member adapted to engage said keeper member, and yielding means carried on said adjustable member interacting between said adjustable member and said lug piece to normally urge said lug piece toward latching position with said keeper member.

4. In a latch device as set forth in claim 3 wherein said latch piece has a crotch portion adapted to be engaged with an outer edge on said keeper member when in fully latched position.

UNITED STATES PATENTS Bain June 20, I911 Bales et a1 July 11, 1933 Bittorf June 26, 1934 Hendricks Sept. 10, 1940 Johannsen May 11, 1943 Anderson et al. Dec. 16. 1952 Erickson 2. Nov. 15, I955

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