Slide fastener lock assembly

Abstract: A slide fastener lock assembly (10) comprises a slider pull tab (13) having an engaging pin (14) and a lock (16) having a locking lug (18c) releasably engageable therewith. The lock (16) has a latch (24) movable toward and away from the locking lug (18 c ) to lock and unlock the pull tab (13). A lock tumbler (25) is rotatable by a key (27) to releasably lock the latch (24) with the engaging pin (14). The pull tab (13) and the lock (16) can be joined together simply by flipping the pull tab (13) down with its aperture (15) fitted over the locking lug (18 c ).

Description: This invention relates to a slide fastener lock assembly for releasably locking a slider pull tab and a lock, said pull tab having an engaging pin at one end and an elongate aperture defined by said pin, said lock including a base plate attached to said garment article, a locking lug dimensioned to fit in the elongate aperture of said pull tab, a latch in the operative position in overlaying relation to said engaging pin, a lock tumbler operatively associated with and rotatable to releasably lock said latch with said engaging pin, and a lock release means adapted to unlock said latch from said engaging pin. A slide fastener lock assembly similar to the type mentioned above is disclosed in US-A-1,680,652 which forms the basis of the preamble of independent claim 1 in which a slider pull tab has at its free end a bent portion provided with an engaging aperture. In the closed condition of the slide fastener, the bent portion of the pull tab may be inserted in an opening provided in an upper surface of a lock having a locking prong engageable in the engaging aperture of the pull tab. Such device has a drawback in that it is quite tedious to have to align the pull tab with the opening of the lock and therefore the user would often leave the pull tab disengaged from the lock when he thinks it unnecessary to completely lock the slide fastener on a bag or the like, in which instance the bag is apt to open up inadvertently while it is being carried. Another drawback in this prior art lock assembly is found in that the pull tab and the lock when joined together form a junction so stiff and hard as to prohibit their relative movement which is urged by bending stresses applied in different directions especially with the slide fastener attached to a flexible garment article such as bags or similar containers, with the results that engaging parts of the device receive localized strains and become susceptible to wear and damage. The present invention seeks to provide an improved slide fastener lock assembly which will eliminate the foregoing difficulties of the prior art and which more specifically has such structural features as to enable the user to clearly view the engagement parts of both a slider pull tab member and a lock member and to ensure smooth and positive lock of both members substantially in any angularly tilted position and further to eliminate localized strains at the engagement parts. A slide fastener lock assembly satisfying these requirements is characterized in Claim 1. The above and other objects and features of the invention will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate by way of example some preferred embodiments. In the accompanying drawings in which like reference numerals refer to like or corresponding parts throughout the several views: Figure 1 is a perspective segmentary view of a slide fastener having mounted thereon a lock assembly embodying the invention; Figure 2 is a perspective view of the lock assembly shown in locked position; Figure 3 is a perspective view of a handbag to which a slide fastener is attached with the lock assembly; Figures 4 through 6 inclusive are longitudinal cross-sectional views of the lock assembly utilized to explain its operation; Figure 7 is an exploded perspective view of the various parts forming the lock assembly; Figure 8 is a diagrammatic side elevational view of the lock assembly shown subjected to upwardly directed bending stress; Figure 9 is a perspective view of a modified lock part of the assembly; and Figure 10 is a diagrammatic side elevational view of the lock assembly having the lock of Figure 9 and shown subjected to downwardly directed bending stress. Referring now to the accompanying drawings and Figure 1 in particular, there is shown a slide fastener F which comprises a pair of oppositely disposed stringer tapes T , T , each carrying along their respective inner longitudinal edges a row of coupling elements E , and a slider S reciprocably movable to open and close the slide fastener F in a manner well known in the art. A support flapper 11 is secured at one of its ends to an end of the slide fastener F as by sewn seams 12 and has the other free end flappingly disposed. The flapper 11 may be alternatively attached in its entirety to a garment article such as a handbag B shown in Figure 3. The slider S includes a pull tab 13 which constitutes one part of a slide fastener lock assembly generally designated 10 embodying the invention and which has one of its ends pivotally connected to a trunnion on the slider body. The pull tab 13 is provided at the opposite end with an engaging pin 14 projecting from and defining with an extreme transverse edge of the pull tab 13 an oblong aperture 15. The engaging pin 14 is preferably circular in cross section for purposes later described. A lock 16, which constitutes the other part of the slide fastener lock assembly 10, is secured to the upper surface of the flapper 11, and comprises various component parts, better shown in Figure 7, including a casing 17 having an opening 17 a directed toward the slider S , a rectangular base plate 18 disposed on the upper surface of the flapper 11 and having a coextensive extension 18 a protruding beyond an end of the casing 17 confronting the slider S , and a cylindrical backing plate 19 secured to the lower surface of the flapper 11. Interposed between the base plate 18 and the backing plate 19 is a connecting plate 20 having a plurality of rivets 20 a . When mounting the lock 16, the rivets 20 a are thrusted through the flapper 11 and passed through holes 19 a into the backing plate 19, in which instance the plate 19 serves as an anvil to bend the rivets 20 a in place. The connecting plate 20 has engaging holes 20 b for receiving engaging pins 18 b downwardly projecting from the bottom of the base plate 18. At an end of the base plate extension 18 a exposed out of the casing 17, there is provided an upwardly extending locking lug 18 c dimensioned to fit in the aperture 15 of the pull tab 13. A resilient member 21 such as in the form of a leaf spring is mounted on the base plate 18 and has bifurcated arms 21 a , 21 a converging toward and joined together by a neck 21 b as better shown in Figure 7, the neck 21 b being located adjacent to the locking lug 18 c and engageable with the engaging pin 14 of the pull tab 13 as shown in Figures 4 and 6. A slide member 22 is slidably mounted within the casing 17 over the resilient member 21 and normally biased toward the locking lug 18 c by means of a spring 23 connected to one or rear end of the slide member 22. At the opposite or front end of the slide member 22 is a latch 24 integral therewith and having an arcuately shaped transverse end surface 24 a at one end and a vertical abutment 24 b as shown in Figures 4 - 6 for purposes later described. A lock tumbler 25 in the form of a polygonal disc is rotatably mounted in the casing 17 in overlying relation to the slide member 22. The lock tumbler 25 has a small-diameter circular bottom 25 a received in an elongate longitudinal slot 22 a formed centrally in the slide member 22 and a large-diameter circular top surface 25 b fitted snugly in a circular cavity 17 b formed in the casing 17. A spring 26 is adapted to bias the lock tumbler 25 toward the casing 17. The lock tumbler 25 further includes a semi-circular peripheral first cam surface 25 c and an off-set vertical flat second cam surface 25 d , the first and second cam surfaces 25 c , 25 d being disposed in diammetrically opposed relation to each other as shown in Figures 4 - 6. On the top surface 25 b of the lock tumbler 25 are formed a plurality of projections 25 e engageable in corresponding recesses 17 c formed in the cavity 17 b of the casing 17. Also formed in the cavity 17 b is a through-opening 17 d for receiving therethrough a key 27 which is in turn received in a key hole 25 f formed in the top surface 25 b of the lock tumbler 25. Designated at 28 is a lock release button having a cap portion 28 a exposed above the casing 17 and a stem portion 28 b connected through an elongate opening 17 e in the casing 17 to a rear end portion of the slide member 22 remote from the latch 24. The lock release button 28 is movable in and along the elongate opening 17 e to release or unlock the latch 24 from the engaging pin 14 of the pull tab 13. With this construction, the slide fastener lock assembly 10 operates as follows: The slide fastener F is fully closed by bringing the slider S into abutting engagement with the flapper 11, whereupon the pull tab 13 is simply flipped down (from the phantom line position in Figure 4) with its aperture 15 fitted over the locking lug 18 c of the lock 16. In this instance, the engaging pin 14 being cross-sectionally circular or rounded off can slide down the arcuate surface 24 a of the latch 24, urging the latter (and the slide member 22) to retract against the tension of the spring 23 and depressing the resilient member 21. Immediately this is done, the latch 24 advances by the action of the spring 23 toward the locking lug 18 c and retains the engaging pin 14, hence the pull tab 13 in locked position with respect to the lock 16. This locked condition is provisional. To make and maintain the slider S fully and completely locked, the key 27 is turned 180° to bring the first cam surface 25 c of the lock tumbler 25 into registered contact with the vertical abutment 24 b of the latch 24 so that the latch 24 remains in overlying relation to the engaging pin 14 of the pull tab 13 as shown in Figure 6. Turning the key 27 another 180° will bring the second cam 25 d of the lock tumbler 25 into registry with the vertical abutment 24 b of the latch 24 to resume a provisional lock condition of the lock assembly 10. The lock release button 28 is then moved backward or toward the right as viewed on the drawings to retract the slide member 22, hence the latch 24 against the tension of the spring 23 so as to release the engaging pin 10 of the pull tab 13, whereupon the resilient member 21 springs back and tosses the engaging pin 14 upwardly out of the lock 16 as illustrated in Figure 5. The slide fastener lock assembly 10 in its locked position on the bag B is often subjected to external stresses tending to flex the flapper 11 up or down. Upwardly directed stresses can be dealt with by relative movement of the pull tab 13 and the lock 16 as shown in Figure 8. Downwardly directed stresses can also be overcome if the flapper 11 carrying the lock 16 is attached in whole to the bag B as shown in Figure 3, because such stresses are blocked by the bag B itself without impairing the lock assembly 10. However, the slide fastener F is sometimes left unsewn and free at one end confronting the flapper 11, in which instance the flapper 11 is susceptible to both upward and downward flexing. To solve this problem, the width of the base plate extension 18 a may be reduced to be equal to that of the locking lug 18 c or smaller than the length of the engaging pin 14 as shown in Figure 9, so that the flapper 11 can flex downwardly at the junction between the locking lug 18 c and the engaging pin 14 in response to downwardly directed stresses as shown in Figure 10 thereby to eliminate possible damage to the lock assembly 10.

Claims: A slide fastener lock assembly (10) for releasably locking a slider pull tab (13) and a lock (16), said pull tab (13) having an engaging pin (14) at one end and an elongate aperture (15) defined by said pin (14), said lock (16) including a base plate (18) attached to said garment article (11), a locking lug (18c) dimensioned to fit in the elongate aperture (15) of said pull tab (13), a latch (24) in the operative position in overlaying relation to said engaging pin (14), a lock tumbler (25) operatively associated with and rotatable to releasably lock said latch (24) with said engaging pin (14), and a lock release means (28) adapted to unlock said latch (24) from said engaging pin (14), characterized in that said locking lug (18c) is provided by an upwardly extending projection of said base plate (18), that said engaging pin (14) is cross-sectionally circular or otherwise rounded off and that said latch (24) has an arcuately shaped end surface (24a). A slide fastener lock assembly (10) according to claim 1 characterized in that said lock tumbler (25) has a first cam surface (25 c ) and a second cam surface (25 d ) in diammetrically opposed relation to each other, said first cam surface (25 c ) being engageable with said latch (24) to lock the latter with said engaging pin (14), and said second cam surface (25 d ) being engageable with said latch (24) when the latter is released from said engaging pin (14) by said lock release means (28). A slide fastener lock assembly (10) according to claim 2 characterized in that it further includes a key (27) adapted to turn said lock tumbler (25) 180° to register said first cam surface (25 c ) with said latch (24) and another 180° to register said second cam surface (25 d ) with said latch (24). A slide fastener lock assembly (10) according to claim 1 characterized in that said lock (16) has an extension (18 a ) equal in width to said locking lug (18 c ). A slide fastener lock assembly (10) according to claim 1 characterized in that it further includes a resilient member (21) normally biasing said engaging pin (14) upwardly toward said latch (24).

Inventors: HORITA YOSHIYUKI, TERADA YASUHARU, HORITA, YOSHIYUKI, TERADA, YASUHARU
Applicants: YOSHIDA KOGYO KK, YOSHIDA KOGYO K.K.
Application year: 1990
Main classification: A44B19
IPC codes: A44B19, C11D17, E05B65