GB2087603A

GB2087603A - Sealing Arrangement for an Extra-flat Waterproof Watch Case

Info

Publication number: GB2087603A
Application number: GB8132482A
Authority: GB
Original assignee: BOUCHET LASSALE SA
Current assignee: BOUCHET LASSALE SA
Priority date: 1980-11-10
Filing date: 1981-10-28
Publication date: 1982-05-26
Also published as: IT8124572A0; IT1139251B; FR2494004B1; GB2087603B; CA1176473A; JPS6246836B2; DE8132874U1; DE3144664A1; CH642219B; CH642219GA3; JPS57106888A; FR2494004A1

Abstract

An extra-flat waterproof watch case has a middle-bezel (2) of thickness substantially equal to that of the case and with a recess in its rear face to receive a back cover (1), the recess forming a shoulder (3). A gasket (10, 11, 12) has, when viewed in transverse cross-section, the general shape of a T, one limb (10) of which is compressed between the back cover (1) and a casing-ring (8) which supports a watch movement, a second limb (11) being compressed between the casing-ring (8) and the middle-bezel (2) and a third limb (12) being compressed between the back cover (1) and the middle-bezel (2). In a simpler embodiment, the gasket is of L-section, the third limb (12) being omitted. <IMAGE>

Description

SPECIFICATION Sealing Arrangement for an Extra-Flat Waterproof Watch Case The invention relates to a waterproof watch case and more particularly to a sealing arrangement between a back cover and a middlebezel of an extra-flat watch that is to say a watch having a thickness less than 4 mm.

According to the invention there is provided a sealing arrangement for an extra-flat waterproof watch case having a middle-bezel of a thickness substantially equal to that of the watch case and having in its rear face a recess to receive a back cover wherein an annular sealing gasket has, when viewed in transverse cross-section, at least two limbs, a first one of which limbs is compressed between the back cover and a casing-ring mounting a watch movement and a second one of which limbs is compressed between the middle-bezel and the casing-ring.

The invention is diagrammatically illustrated way of example in the accompanying drawings, in which: Figure 1 is a partial radial cross-section through a watch taken on the axis of a winding stem and showing a first embodiment of a sealing arrangement according to the invention; and Figure 2 is a view similar to Figure 1 through a second embodiment.

With reference to Figure 1 a watch case comprises a back cover 1 located in a first recess in the rear face of a middle-bezel 2 and resting on a first lower shoulder 3 of the middle-bezel 2.

The back cover 1 is fixed in position by means of a screw thread (not shown) provided on a face of the middle-bezel 2 perpendicular to the shoulder 3. The middle-bezel 2, which has a thickness substantially equal to the total thickness of the watch and less than 4 mm, has a recess in its upper face forming an upper shoulder 5 against which a watch glass 6 is engaged.

The tightness between the glass 6 and the middle-bezel 2 can be obtained in any suitable known manner, particularly by gluing.

Also in the rear face of the middle-bezel 2 there is a second recess defining a second lower shoulder 7 of smaller dimensions than the first lower shoulder 3 receiving the back cover 1.

A casing-ring 8 is provided for mounting the watch movement. The casing-ring 8 is received together with a dial 9, in a third recess in the underside of the middle-bezel 2, the third recess forming a third lower shoulder 1 3 and having a smaller dimension than the recess forming the shoulder 7.

The casing-ring 8 has a stepped rear face whereby it forms, with the adjacent wall of the middle-bezel 2, an annular recess.

A sealing gasket of a supple material is of annular form and circular or polygonal shape depending on the watch shape. The gasket, in transverse cross-section, has three limbs 10, 11, 12. The first limb 10 is compressed between the back cover 1 and the casing-ring 8, which casingring 8 bears through the intermediaray of the dial 9 against the third lower shoulder 13 of the middle-bezel 2.

The second limb 11 of the resilient gasket is compressed between the casing-ring 8 and the middle-bezel 2 and the third limb 12 of the gasket is compressed between the back cover 1 and the middle-bezel 2.

The main advantage of such a gasket is that it can ensure a seal simultaneously between the back cover 1, the middle-bezel 2 and the casingring 8 and above all that it is completely located in recesses in the middle-bezel 2 and of the casing-ring 8 so that it does in no way increase the thickness of the case and also that it is neither accessible nor visible from the outside of the case.

The dimensions of the gasket 10, 11, 12 are such that in its service position shown, it is compressed in its totality between the back cover 1 on the one hand and the casing-ring 8 and the middle-bezel 2 on the other hand. Furthermore the limb 11, located between the casing-ring 8 and the middle-bezel 2, is also compressed in a direction extending radially with respect to the case.

With such a T-shaped gasket one can obtain an effective seal up to several atmospheres, for example three to four atmospheres, with only one gasket, the manufacture of which and the setting in place of which can be relatively simple, and without causing any increase in the thickness of the extra-flat case.

The construction can be very easy to manufacture since the machinings can be simple and assembly straightforward so that a tight seal can be easily guaranteed.

In the second embodiment shown in Figure 2 the gasket comprises only the two limbs 10, 11 and has thus in cross-section the general shape of an L.

Here the casing-ring 8 shows in transverse cross-section the shape of a Z. The gasket 10, 11 in its service position is axially compressed in its totality between the back cover 1 and the casingring 8 and the limb 11 is also compressed radially between the casing-ring 8 and the middle-bezel 2.

Here again the same advantages are found as in the first embodiment described.

It is evident that the sealing arrangement described can be used either with a circular case or with other shaped cases and this is still a further advantage.

Claims

1. A sealing arrangement for an extra-flat waterproof watch case having a middle-bezel of a thickness substantially equal to that of the watch case and having in its rear face a recess to receive a back cover wherein an annular sealing gasket has, when viewed in transverse cross-section, at least two limbs, a first one of which limbs is compressed between the back cover and a casing-ring mounting a watch movement and a second one of which limbs is compressed

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Sealing Arrangement for an Extra-Flat Waterproof Watch Case The invention relates to a waterproof watch case and more particularly to a sealing arrangement between a back cover and a middlebezel of an extra-flat watch that is to say a watch having a thickness less than 4 mm. According to the invention there is provided a sealing arrangement for an extra-flat waterproof watch case having a middle-bezel of a thickness substantially equal to that of the watch case and having in its rear face a recess to receive a back cover wherein an annular sealing gasket has, when viewed in transverse cross-section, at least two limbs, a first one of which limbs is compressed between the back cover and a casing-ring mounting a watch movement and a second one of which limbs is compressed between the middle-bezel and the casing-ring. The invention is diagrammatically illustrated way of example in the accompanying drawings, in which: Figure 1 is a partial radial cross-section through a watch taken on the axis of a winding stem and showing a first embodiment of a sealing arrangement according to the invention; and Figure 2 is a view similar to Figure 1 through a second embodiment. With reference to Figure 1 a watch case comprises a back cover 1 located in a first recess in the rear face of a middle-bezel 2 and resting on a first lower shoulder 3 of the middle-bezel 2. The back cover 1 is fixed in position by means of a screw thread (not shown) provided on a face of the middle-bezel 2 perpendicular to the shoulder 3. The middle-bezel 2, which has a thickness substantially equal to the total thickness of the watch and less than 4 mm, has a recess in its upper face forming an upper shoulder 5 against which a watch glass 6 is engaged. The tightness between the glass 6 and the middle-bezel 2 can be obtained in any suitable known manner, particularly by gluing. Also in the rear face of the middle-bezel 2 there is a second recess defining a second lower shoulder 7 of smaller dimensions than the first lower shoulder 3 receiving the back cover 1. A casing-ring 8 is provided for mounting the watch movement. The casing-ring 8 is received together with a dial 9, in a third recess in the underside of the middle-bezel 2, the third recess forming a third lower shoulder 1 3 and having a smaller dimension than the recess forming the shoulder 7. The casing-ring 8 has a stepped rear face whereby it forms, with the adjacent wall of the middle-bezel 2, an annular recess. A sealing gasket of a supple material is of annular form and circular or polygonal shape depending on the watch shape. The gasket, in transverse cross-section, has three limbs 10, 11, 12. The first limb 10 is compressed between the back cover 1 and the casing-ring 8, which casingring 8 bears through the intermediaray of the dial 9 against the third lower shoulder 13 of the middle-bezel 2. The second limb 11 of the resilient gasket is compressed between the casing-ring 8 and the middle-bezel 2 and the third limb 12 of the gasket is compressed between the back cover 1 and the middle-bezel 2. The main advantage of such a gasket is that it can ensure a seal simultaneously between the back cover 1, the middle-bezel 2 and the casingring 8 and above all that it is completely located in recesses in the middle-bezel 2 and of the casing-ring 8 so that it does in no way increase the thickness of the case and also that it is neither accessible nor visible from the outside of the case. The dimensions of the gasket 10, 11, 12 are such that in its service position shown, it is compressed in its totality between the back cover 1 on the one hand and the casing-ring 8 and the middle-bezel 2 on the other hand. Furthermore the limb 11, located between the casing-ring 8 and the middle-bezel 2, is also compressed in a direction extending radially with respect to the case. With such a T-shaped gasket one can obtain an effective seal up to several atmospheres, for example three to four atmospheres, with only one gasket, the manufacture of which and the setting in place of which can be relatively simple, and without causing any increase in the thickness of the extra-flat case. The construction can be very easy to manufacture since the machinings can be simple and assembly straightforward so that a tight seal can be easily guaranteed. In the second embodiment shown in Figure 2 the gasket comprises only the two limbs 10, 11 and has thus in cross-section the general shape of an L. Here the casing-ring 8 shows in transverse cross-section the shape of a Z. The gasket 10, 11 in its service position is axially compressed in its totality between the back cover 1 and the casingring 8 and the limb 11 is also compressed radially between the casing-ring 8 and the middle-bezel 2. Here again the same advantages are found as in the first embodiment described. It is evident that the sealing arrangement described can be used either with a circular case or with other shaped cases and this is still a further advantage. Claims

1. A sealing arrangement for an extra-flat waterproof watch case having a middle-bezel of a thickness substantially equal to that of the watch case and having in its rear face a recess to receive a back cover wherein an annular sealing gasket has, when viewed in transverse cross-section, at least two limbs, a first one of which limbs is compressed between the back cover and a casing-ring mounting a watch movement and a second one of which limbs is compressed between the middle-bezel and the casing-ring.

2. A sealing arrangement according to claim 1, wherein the gasket has a third limb compressed between the back cover and the middle-bezel.

3. A sealing arrangement according to claim 1, wherein the gasket presents in transverse crosssection the shape of an L.

4. A sealing arrangement according to claim 2, wherein the gasket presents in transverse crosssection the shape of a T.

5. A sealing arrangement according to one of the preceding claims, wherein the gasket in its service position is compressed axially in its totality and its second limb is compressed radially between the casing-ring and the middle-bezel.

6. A sealing arrangement for an extra-flat waterproof watch case substantially as hereinbefore described and illustrated with reference to the accompanying drawings.