IL191518A - Device for securing a watch strap to a watch casing - Google Patents

Description

191518/2 191518 |7·3Ί I 45358Η ΤΛΊΝ Device for Securing a Watch Strap to a Watch Casing Device for securing a watch strap to a watch casing FIELD OF THE INVENTION This invention relates to wrist watches and in particular to the manner in which a bracelet is mounted thereon.

BACKGROUND OF THE INVENTION Conventionally a watch strap has at opposite ends a tubular portion through which a spring loaded telescopic pin is inserted whose ends are accommodated in opposing recesses of a lug protruding from opposite edges of a watch casing. Such an arrangement is described, for example, in WO 98/21630. The fixing and removal of the watch strap requires use of a tool to withdraw or push back the pin connecting it to the lugs of the casing.

WO 99/36838 discloses a device for rapid fixing of a watch strap on a watch casing without a tool. This device comprises a first intermediate element mounted on the watch casing and that can slide or turn relative to this watch casing. A second intermediate element to which is fixed the watch strap, can engage the first intermediate element when the latter is in a mounting position relative to the watch casing. In normal service position of this first intermediate element relative to the watch casing, the second intermediate element is locked in a position coupled to the first intermediate element.

Swiss patent CH 614,589, discloses a watch casing whose lugs are provided with hinges, having a longitudinal recess open at the end and on the internal surface of the hinge. The bracelet is fixed to a transverse bar whose cross section has the shape of a truncated cylinder permitting in a predetermined angular position to be introduced into the recess of the hinge of the watch casing. For all the other angular positions of this bar relative to the hinge, this bar is trapped in the hinge. Here again, the watch strap can inadvertently separate from the watch casing. - 2 - 191518/3 US Pat. No. 5,668,784 (Iguchi) discloses a watch band attachment mechanism for attaching a continuous band to a watch case by means of a pair of band attachments with holding members each having an insertion slot through which the watch band is inserted. Such an arrangement is not suitable for a conventional strap or bracelet as described above.

US Pat. No. 6,408,491 (Guyard) discloses a device for securing a watch strap to a watch casing. The device includes an intermediate element to which the end of the watch strap is fixed and which is received between the lugs of the watch casing by sliding in a complementary formation on the lateral surfaces of the intermediate element and the internal surfaces of the lugs. The intermediate element comprises a flap that is resiliently pivoted about an axis transverse to the watch strap and including a locking nose that co-acts in use with a locking surface on the end surface of the watch casing.

US Pat. No. 5,197,046 discloses a wrist watch and wrist watch strap combination includes a pair of manually operable clasps for securing the ends of the strap to the watch. The owner can change the strap without using tools.

US 2006/0114753 discloses a timepiece whose bezel is interchangeable via a bayonet device. The shoulder of the middle part is provided with a circular groove and at least two sinks opening out partially into said groove. The bezel includes at least two feet positioned to engage in the sinks, said feet each including a notch open radially at the emergence of the sinks. A locking ring provided with an outer member for rotational manipulation, is positioned in the groove, one edge of said ring having a substantially equal thickness to the aperture of the notches and including recesses for the feet to pass and the other edge including a gorge facing a gorge of the middle part, the two gorges housing a click spring of the ring.

There is no suggestion in any of these references to utilize the bezel for securing the clasps that hold the bracelet so as to prevent inadvertent removal of the bracelet.

GB 2 273 796 discloses a wrist-watch 10 incorporating a watch casing 11 which comprises a generally flat body 12 which has a top face on which time is to be displayed and opposite end lugs 13 for connection to corresponding ends of a watch strap 28, band or bracelet. The watch casing further includes a bezel ring 25 disposed around on the body top face, and a securing ring 26 associated with the bezel ring and co-operable with the respective body end lugs to secure corresponding ends of the watch strap, band or bracelet. - 3 - 191518/3 The body 12 has an outer diameter, excluding end lugs 13 to which the bracelet is attached, that is slightly smaller than that of the bezel ring 25, resulting in the bezel ring 25 overlapping with the end lugs 13. Before the bezel ring 25 is fitted, the horizontal annular gap between the bezel ring 25 and the body 12 immediately above the end lugs 13 is preoccupied by a securing ring 26. The securing ring 26 is sandwiched in position by the bezel ring 25 and has a pair of diametrically opposite end lugs 27 which are aligned with the corresponding end lugs 13 of the body member 12.

Respective securing pins 29 are attached to opposite ends of the strap or bracelet in known manner and each pin 29 is located in an open channel formed by a respective hook-like member in the end lug 13. The open channel is subsequently closed by a corresponding end lug 27 of the securing ring 26, thereby securing the end of the strap 28 and preventing its unintended removal.

Thus, GB 2 273 796 does use the bezel for securing the bracelet so as to prevent inadvertent removal of the bracelet. However, it does not do so directly but rather requires the intermediate securing ring 26. It will be noted that the securing ring 26 is a generally annular component that surrounds the watch casing and is fitted with opposing lugs 27 that are shaped for flush accommodation with the lugs 13 of the casing. This is wasteful of material since, in fact, only the lugs 27 serve the purpose of actually securing the bracelet - and this only when the bezel ring 25 is fitted.

It would therefore be preferable to use the bezel ring directly without the need for the securing ring.

SUMMARY OF THE INVENTION The invention provides an alternative device for attaching a conventional bracelet to a watch casing without the need for a tool and having a simpler construction than known devices. More particularly it allows a bezel ring that is in any case provided to allow for easy changing of the watch face to serve the additional function of securing the bracelet without the need for additional components.

According to the invention there is provided a casing for a wrist watch, said casing comprising: a pair of clasps protruding from opposite sides of the casing, each clasp being hingedly moveable from an open position wherein the clasp can engage an end of a - 4 - 191518/3 bracelet to a closed position wherein the end of the bracelet is securely held by the clasp and wherein a locking element on the clasp abuts an upper rim of the casing, and a locking ring that can be removably attached to an upper periphery of the casing for engaging respective ends of the locking elements thereby locking both of the clasps in their closed positions and preventing the respective ends of the bracelet from inadvertently disengaging.

In such an arrangement the clasps co-operate directly with the bezel ring to secure the bracelet offering a simpler and less expensive arrangement than GB 2 273 796.

BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Fig. 1 is pictorial representation of a watch casing according to an embodiment of the invention; Figs. 2a, 2b and 2c show components of the watch casing depicted in Fig. 1 in spaced relationship; Fig. 3 is a cross-sectional elevation of the watch casing as seen through the line A-A in Fig. 2b; and Fig. 4 shows a clasp of the watch casing in an open position.

DETAILED DESCRIPTION OF EMBODIMENTS Fig. 1 is pictorial representation of a watch casing 10 having a pair of clasps 11 protruding from opposite sides of the casing 10. Figs. 2a, 2b and 2c show components of the watch casing 10 in spaced relationship. Thus, Figs. 2a and 2b show a base portion 12 that accommodates a watch mechanism 13 in known manner. The base portion 12 has a peripheral upper rim 14 adapted for screw mounting of a locking ring 15 shown in Fig. 2c. Each of the clasps 11 comprises a respective lug 16 protruding from opposite edges of the base portion 12 at the 6 o'clock and 12 o'clock positions. Locking portions 17 are hingedly attached to respective first ends of the lugs 16 via pins 18. The lugs 16 and the locking portions 17 are each provided with a respective central semi-circular recess 19 and 20 so that when the locking portions 17 are closed as shown on the left side of Fig. 3, there is a formed a circular aperture 21 for accommodating a mounting - 5 - 191518/3 pin of a watch bracelet (not shown). To this end, the bracelet is provided with its own integral mounting pins at opposite ends thereof. Fig. 4 shows the clasp 11 in an open position.

The locking portions 17 are each provided at respective second ends thereof remote from their respective points of attachment to the lugs 16 with respective outwardly protruding lips 22 which are configured to lie on the peripheral rim 14 of the base portion 12 when the clasps 11 are closed. When the locking ring 15 is now attached to the base portion 12, the lips 22 are thus secured by the locking ring 15 and cannot open inadvertently, thereby preventing the clasps 11 from opening. Preferably, the locking ring 15 has an internal threaded portion 23 for screw attachment to the peripheral upper rim 14, which is provided with a complementary external thread 24. This enables the bracelet to be mounted and removed without the need for tools of any kind.

In use, the locking ring 15 is removed simply by rotating in a counter-clockwise direction whereupon the clasps can be opened and the bracelet either removed or inserted as required. Since the bracelet has its own integral mounting pins at opposite ends thereof, the mounting pins (not shown) are simply mounted within the open recesses 19 of the lugs 16 for free rotation within the circular apertures 21 formed when the locking portions 17 are closed. The locking ring 15 is now replaced, again without the need for special tools, so as to secure the bracelet.

The invention thus provides an effective attachment device that is very simple, robust, and easy to machine and assemble. It permits coupling and uncoupling of the watch strap from the watch casing easily and without any tool, but, because of the locking, it prevents any inadvertent separation of the bracelet from the casing.

Although the invention is of particular benefit when the locking ring is threadably attached to the periphery of the base portion, it will be appreciated that it may also be adapted for press-fit mounting on to the peripheral rim of the base portion.

Likewise, although the lugs of the clasps are shown protruding from opposite edges of the base portion, their manner of attachment is not a feature of the invention. They may be machine mounted to the base portion or may be accommodated in opposite recesses formed in the base portion.

Claims (6)

- 6 - 191518/2 CLAIMS:

1. A casing for a wrist watch, said casing comprising: a pair of clasps protruding from opposite sides of the casing, each clasp being hingedly moveable from an open position wherein the clasp can engage an end of a bracelet to a closed position wherein the end of the bracelet is securely held by the clasp and wherein a locking element on the clasp abuts an upper rim of the casing, and a locking ring that can be removably attached to an upper periphery of the casing for engaging respective ends of the locking elements thereby locking both of the clasps in their closed positions and preventing the respective ends of the bracelet from inadvertently disengaging.

2. The casing according to claim 1, including a base portion for supporting a watch mechanism and having a peripheral upper rim adapted for securing the locking ring.

3. The casing according to claim 2, wherein each of the clasps comprises: a lug protruding from opposite edges of the base portion and having a central semi-circular recess, a locking portion hingedly attached at a first end to the lug via a pin and having a central semi-circular recess, an outwardly protruding lip at a second end of the locking portion opposite the first end thereof and being configured to lie on the peripheral rim of the base portion when the clasp is closed; whereby when the locking portion is closed prior to securing the locking ring a circular aperture is formed for accommodating a mounting pin of a watch bracelet, and when the locking ring is now attached it secures the respective lip of each clasp thereby preventing the clasps from opening.

4. The casing according to claim 2 or 3, wherein the locking ring is adapted for threaded attachment to the peripheral rim of the base portion.

5. The casing according to any one of claims 1 to 4, wherein the clasps are mounted in respective recesses in opposite edges of the casing. - 7 - 191518/1

6. A casing for a wrist watch according to claim 1, substantially as described herein with reference to the accompanying drawings. For the Applicants, WOLFF, BREGMAN AND GOLLER