GB2173927A

GB2173927A - Wrist-watch casing

Info

Publication number: GB2173927A
Application number: GB08609105A
Authority: GB
Inventors: Toru Takagi
Original assignee: Orient Watch Co Ltd
Current assignee: Orient Watch Co Ltd
Priority date: 1985-04-17
Filing date: 1986-04-15
Publication date: 1986-10-22
Also published as: KR890001349B1; GB8609105D0; CH667769GA3; JPH0320795Y2; KR860008482A; DE3612450C2; JPS61173086U; GB2173927B; FR2580832A1; FR2580832B1; DE3612450A1

Abstract

An airtight wrist-watch casing comprises a flat, tubular, transparent main body 1, a bar-like inner case 8 of reduced cross section mounting the movement and a pair of tightly sealed end closures 5. This provides the visual effect of transparency as in a see-through wrist-watch, while providing enhanced waterproof protection of the movement. The end closures 5 carry means 4 for attaching a wrist strap. <IMAGE>

Description

SPECIFICATION Wrist-watch casing The present invention relates to casings suitable for housing the movement of wristwatches. Prior wrist-watch casings have been constructed with small numbers of parts so that the assembly is achieved with fewer joints and hence at lower costs than other casings. Also their designs have been proved to offer increased waterproof performance because of the small number of joints. These casings are commonly known as one-piece casings. In some constructions, as proposed in laid open Japanese Utility Model application no: 96285/1983, waterproofing is further enhanced by the arrangement that, in assembly, the movement is inserted into position within the casing through an aperture defined in a side of the casing making it possible to reduce aperture size.

However, these conventional wrist-watch casings have the problem that design and construction are more or less limited, above all, by the requirement of housing the movement, making it virtually impossible to provide freedom in designing the casing independently of the movement it is intended to encase.

With the marked development of electronics, those recent portable timepieces equipped with highly. integrated circuits and extra-mini crystal oscillators have become gradually smaller. However, a disadvantage of this miniaturisation trend is some are constructed too small for practical use when worn on the user's wrist and, what is worse, so small that an effort is required even to read the time.

It is therefore an object of the present invention to provide a casing of simple construction with excellent waterproofing suitable for housing the movement of a wrist-watch.

According to the invention a wrist-watch casing comprises a flat, tubular main portion made from a transparent material, an inner mounting of reduced cross section provided in the inside of the main portion and adapted to hold the movement of a timepiece, and a pair of closure members each having a connection for a wrist-watch band for closing the open ends of the main portion.

Examples of such constructions will now be described, with reference to the accompanying drawings, in which: Figure 1 is an exploded, perspective view of a typical embodiment of the wrist-watch casing constructed in accordance with the present invention; Figure 2 is a cross sectional view of the important part of the embodiment of Fig. 1; Figure 3 is an exploded, perspective view of another embodiment according to the present invention; and Figure 4 is an exploded, perspective view of a further embodiment according to this invention.

Referring first to Figs. 1 and 2, a wristwatch casing includes a flat tubular main portion 1 made from a transparent or semi-transparent material such as glass or polystyrene, suitably sized for mounting on the wrist. Each of the open ends of the main tubular portion 1 is airtightly closed by a stepped end 6 of a closure 5 with the inter-position of a seal 3 in the junction between the main portion 1 and closure 5.

Inside the main portion 1 is provided an inner case 8 in which the movement 9 is installed in position. The length of the inner case 8 is such that it is affixed at opposite ends to the internal sides of the cldsures 5, respectively. Also the inner case 8 may preferably be built into a bar or plate of reduced cross section such as to provide ample space above its surface within the inside of the main portion 1. The inner case 8 may be gold plated in the surface the ornamental purposes.

The opposite end faces of the inner case 8 may be fixed integrally with the respective closures 5 with screws and each closure member 5 has a connection 4 for connection to the end of a wrist-watch strap. In the bottom side of the inner case 8 is formed in the centre a recess 10 to receive therein the movement 9 in fixed position.

The movement 9 is installed in the recess 10 such that its hour and minute hands 11 and 12, mounted at the upper spindle end, come above the surface of the inner case 8 with the winding screw 13 at the side, and airtightly enclosed by a bottom cover 9.

In assembly, one of the closures 5 is first secured to the end face of the inner case 8 with screws 7, and the inner case 8 with the closure 5 is fully inserted from the opened end of the main portion 1, so that the unattached end face of the inner case 8 comes at the opposite open end. To that end is attached the other closure 5 with screws 7 so that the inner case 8 is encased airtightly within the inside of the main portion 1. Because of this simplicity of construction, the main portion may be made from any practical transparent or semi-transparent material, with the substantially same airtightness. Hard to work materials, such as inorganic glass, may also be employed since much working is not required in building the main portion 1 for this casing.

Furthermore, the casing may be constructed in a design that emphasises the visual effect of transparency, as in a see-through wristwatch, by making the best use of the space defined above the inner case surface beneath the transparent upper main portion side. In addition, the overali design provides for an increased waterproof protection of the movement 9, doubly enclosed by the recess 10 in conjunction with the bottom cover 11 closing the recess and the main portion.

Referring then to Fig. 3, a second embodiment of the present invention is similar to the previous embodiment, except that one of the closures 25 is made integral with a mounting base 28 of a length substantially equal to the main body 21 such that the other end is secured fixedly to the internal face of the other closure 25 through an attachment 29 formed at that end. The mounting base 28 is provided with a mount for the movement 9.

Referring further to Fig. 4, a third embodiment is also similar to the first embodiment, except that a pair of end plates 32 are interposed between the main portion 1 and the closure 35 at each open end of the main portion 1. The end plate 32 is fixed to the respective closure 35 with screws 37, with the inter-position of a seal or sealant, which may be applied to the external surface of the end plate 32. In this particular embodiment, the inside case 38 with the movement mounted is inserted into the inside of the main portion 31 through an aperture 33 in one of the end plates 32.

Claims

1. A wrist-watch casing comprising a flat, tubular main portion, made from a transparent material, an inner mounting of reduced cross section provided in the inside of the main portion and adapted to hold the movement of a timepiece, and a pair of closure members each having a connection for a wrist-watch band for closing the open ends of the main portion.

2. A wrist-watch casing as set forth in claim 1, wherein the inner mounting base is integral with the internal surface of one of the closures, the mounting being substantially equal in axial length to the main portion and provided at its opposite end with a connection for fixing to the internal surface of the other closure when the mounting is inserted into the main portion.

3. A wrist-watch casing as set forth in claim 1 or claim 2 and including an end plate interposed between each closure and the respective open end of the main portion.

4. A wrist-watch casing as set forth in claim 3, wherein one of the end plates is formed with an aperture to permit the insertion into the main portion of the inner mounting fixed to the internal surface of the closure on the corresponding side.

5. A wrist-watch casing as set forth in claim 1, wherein the inner mounting is a bar or plate substantially equal in axial length to the main portion so as to be secured at both ends to the internal surfaces of the closure members.

6. A wrist-watch casing substantially as described and as illustrated with reference to Figs. 1 and 2 or Fig. 3 or Fig. 4 of the accompanying drawings.