GB2082666A - Hook fastener - Google Patents

Abstract

A fastener suitable for releasably fastening the ends of bracelets and watch straps has two members for attachment to the ends to be fastened. One member 16 has hooks 23, 24 to engage a catch 6 on the other member 1. An abutment 5 on one member is spaced from the hooks in a direction in which the hooks need to be moved to release it from the catch. A pivoted lever 17 on the other member 1 carries a locking element 25 positioned to engage the abutment to prevent movement of the hooks in that releasing direction. <IMAGE>

Description

SPECIFICATION Improved fastener This invention relates to fasteners of the kind having a releasably interlocking pair of discrete members.

The invention has particular, but not exclusive, application to bracelet fasteners, the term "bracelet" being intended in this specification to include metal bracelets, and straps such as watch straps.

In our United Kingdom Patent Application No.

41438/78 we have set forth a fastener of this kind having a hook on a first of the discrete members, a catch on the second of the discrete members to engage with said hook, an abutment on one of the discrete members and spaced from the hook or from the catch respectively, a lever on the other of the discrete members pivotable relative to the catch or hook thereof as the case may be, and a locking element carried by the lever for movement therewith so as to be capable of being received, with resilient deformation, between the abutment and the hook (engaged on the catch) to retain the hook and catch in engagement.

The object of the present invention is to provide a fastener which is an improvement over the fastener of the preceding paragraph and the features and advantages of which will be apparent from the following description.

According to the present improvement, a fastener comprises interlocking first and second discrete members and has hook means on the first member, a catch on the second member for engagement by the hook means, an abutment on one of said members spaced from the hook means or catch thereof in the direction for engagement and disengagement of the hook means and catch, a lever on the other of said members and pivotally movable relative to the catch or hook means thereof, and a locking element carried by the lever for movement therewith to be resiliently engaged with the abutment such that the hook means are prevented from movement to disengage from the catch.

In a preferred arrangement, the lever is on the first member.

Conveniently the locking element is made resiliently deformable, but for proper operation it is only necessary that there shall be a capability of resilient deformation in one or more of the hook means, the catch, the lever, the locking element, and the abutment.

The locking element may comprise a resiliently deformable arm or plate provided on the lever and preferably including a recessed formation into which the abutment is adapted to engage releasably as a snap-fit.

The first member may include a hooking member having a base portion and upstanding side walls, the hooking means being provided at an edge of said base, and the lever being carried by pivot means on the side walls.

The catch may be a rod on the second member, and the abutment may be another rod on the second member parallel to the first rod. The second member may be "U"-shaped, with a web and upstanding arms, the two rods extending between the arms and spaced from the web.

Desirably, clamping means are provided for releasably clamping a bracelet (as hereinbefore defined) against the web. Said clamping means may comprise a clamping plate, especially a spring plate, disposed between said arms and a cam pivotably mounted on the abutment rod for movement to abut against said plate. The cam may be formed on a sleeve rotatably mounted on the abutment rod and carrying a clasp plate movable therewith to engage the bracelet. Advantageously the clasp plate has projection at its distal end to enhance engagement with the bracelet. The clamping plate may be mounted for limited movement, relative to the arms, towards and away from the bracelet. By way of example, the clamping plate may have projecting ears located in slots provided in the arms.Clamping of the bracelet between the clamping plate and the web may be enhanced by providing at least one projection on the surface of the web facing the clamping plate. In the embodiment having a "U" shaped base to the second member, it is preferred that the lever is in the form of a plate which, in the fastened condition of the fastener, closes the upper part of the base, remote from the web.

In order that the nature of the invention may be readily ascertained, an embodiment of fastener in accordance therewith is hereinafter particularly described by way of example with reference to the figures of the accompanying drawings, wherein Figure 1 is a perspective elevation of first and second members of the fastener, seen in disassembled condition; Figure 2 is a perspective elevation of the fastener with the first and second members seen in assembled condition; Figure 3 is a plan view of the assembled fastener; Figure 4 is a section taken on the line IV-IV of Figure 3.

Referring to the drawings, the fastener comprises a member (the "second" member) having a Ushaped base 1 including a base web 2 and two side arms 3 and 4. An abutment rod 5 is mounted by its ends in openings in the arms 3 and 4, and extends parallel to the web 2 but spaced above it. A catch rod 6 is mounted by its ends in openings in the arms 3 and 4, and extends parallel to the abutment rod 5, and also parallel to and spaced above the web 2. In each of the arms 3, 4 there is provided a slot 7. A spring plate 8 is positioned above the web 2 and has ears 9 at each side to engage loosely in the slots 7 so that the plate is retained against longitudinal movement but can move up and down and tilt within limits, to permit the accommodation, between the web 2 and the plate 8, of wrist watch bracelets 10 of different thicknesses (see Figure 4).Secure fastening of the bracelet 10 to the member is enhanced by the provision of a pair of projections 11 upstanding on the upper surface of the web 2 at a position below the rod 5.

On the rod 5 there is pivotably mounted a bracelet retainer 12 having a curved portion engaged about the rod 5 and provided with a projecting cam 13 which can bear on the upper surface of the plate 8 to press the plate downwardly onto the bracelet such that the bracelet is forced into firm engagement with the web 2 and the projections 11 thereon. The retainer 12 further comprises a clasp plate 14 having projections 15 at its free end for engagement with the bracelet 10.

The other member (the "first" member) of the fastener is indicated generally by reference numeral 16 and includes a curved lever plate 17 which is engaged at one end about a pivot rod 18 engaged at its ends in aperture in side walls 19 of a hooking member 20. A pin 21, for connection of the other end of the bracelet, is engaged at its ends in apertures of the side walls 19. An edge of a base portion 22 of the hooking member carries two spaced hooks 23, 24 the purpose of which will be explained below.

On the underside of the lever plate 17 there is provided a resilient locking arm or plate element 25, having a recessed formation into which the abutment rod 5 can be engaged releasably as a snap-fit.

For attachment of a bracelet 10 to the second member, the bracelet retainer 12 is moved to a position in which the clasp plate 14 is pointed upwardly away from the base web 2, whereby the cam 13 is moved awayfrom abutment against the plate 8. An end of the bracelet 10 is then threaded between the web 2 and the plate 8 to the desired longitudinal position. Then the bracelet retainer 12 is moved anti-clockwise (in Figure 4) until the cam 13 abuts the plate 8 and presses it down onto the bracelet, and the projections 15 have come into engagement with the upper surface of the bracelet.

The other end of the bracelet is secured to the "first" member 16 by conventional engagement of the end section of the bracelet with the pin 21.

Fastening together of the two components of the fastener takes place asfollows: The lever plate 17 and the hooking member 20 of member 16 are moved to the open position seen in Figure 1. The hooks 23 and 24 are then engaged over the catch rod 6. The lever plate 17 is then moved down anti-clockwise (in Figure 4) until the resilient locking element 25 is felt to abut against the central portion of the abutment rod 5. Further pressure applied to the lever plate 17 will cause the locking element 25 to deform resiliently until the lever plate 17 reaches a fully closed condition and the rod 5 has snapped into the recessed zone of the locking element The resilient engagement of the locking element 25 with the rod 5 tends to retain the lever plate 17 in closed position, in which the lever plate 17 closes the uperpartofthe base. Such engagement also ensures that the hooking member 20 cannot move longitudinally, relative to the catch rod 6, sufficiently for disengagement of the hooks 23,24 from the catch rod.

To release the fastener, the free end of the lever plate 17 is lifted upwardly, say with the finger-nail, to force the locking element 25 out of engagement with the rod 5, whereafter the lever plate 17 can be moved fully clockwise and the hooking member 20 then moved slightly forwardly to permitthe hooks 23,24 to be disengaged from the catch rod 6.

Claims (14)

1. A fastener comprising first and second discrete members for attachment to respective items to be fastened releasablytogether, hook means on said first member, catch means on said second member for engagement by said hook means, an abutment on one of said members spaced from the hook means or catch means respectively thereof in that direction in which the hook means must be moved relative to the catch means for disengagement therefrom, lever means on the other of said members pivotably movable relative to the catch means or hook means respectively thereof, and locking " element means carried by said lever for movement therewith and positioned so as in a locking end position of said lever to engage with said abutment means so as to prevent movement of said hook means relative to said catch means in said direction.

2. A fastener, as claimed in Claim 1, wherein said lever means is a said first member, and said abutment is on said second member.

3. Afastener, as claimed in either of Claims 1 and 2, wherein any one or more of said hook means, said catch means, and said locking element means is resiliently deformable, such that the engagement of said locking element means with said abutment means occurs with resilient deformation so that the locking element is retained in resiliently releasable manner in the engaged position.

4. Afastener, as claimed in any one of Claims 1 to 3, wherein said first member includes a base portion and side walls upstanding on said base member, said hooking means being provided at a transverse edge of said base portion, and said lever means being journalled on said side walls.

5. Afastener, as claimed in any one of the preceding Claims, wherein said catch means and said abutment means are respective parallel rods on said second member.

6. Afastener, as claimed in Claim 5, wherein said second member includes a transverse web with upstanding side arms thereon, said rods being carried by and extending between said side arms.

7. A fastener, as claimed in Claim 6, comprising releasable clamping means for clamping a said item against said transverse web.

8. Afastener, as claimed in Claim 7, wherein said clamping means comprises a clamping plate disposed between said side arms and spaced from said transverse web, and cam means rotatably carried on said abutment rod for movement into clamping and releasing end positions in which it respectively urges said clamping plate towards said transverse web, and releases said clamping plate.

9. A fastener, as claimed in Claim 8, wherein said cam means is formed on a sleeve rotatably mounted on said abutment rod and carrying a clasp plate which abuts said item in said clamping position.

10. A fastener, as claimed in Claim 9, wherein said clasp has on or more projections at its distal end to abut said item to enhance engagement therewith.

11. Afastener, as claimed in any one of Claims 8 to 10, wherein said clamping plate has projecting ears each engaged in a slot provided in a respective side arm, thereby to permit limited movement of the clamping plate towards and away from the web.

12. A fastener, as claimed in any one of Claims 8 to 11, wherein at least one projection is provided on a surface of said web facing said clamping plate, to enhance clamping of said item therebetween.

13. Afastener, as claimed in any one of Claims 6 to 12, wherein said lever means is a plate which, in the fastened condition of the fastener, overlies substantially all of said transverse web between said side walls.

14. A fastener substantially as described herein with reference to the accompanying drawings.