Crystal Mounting Structure For A Water-proof Watch

Abstract

A crystal mounting structure for a water-proof watch comprising a bezel provided with a projection having an inner diameter smaller than the outer diameter of a glass crystal. A first sealing member is interposed between the bezel and glass crystal and a second sealing member is interposed between the bezel and a case. A mounting ring is provided between the glass crystal and the case for holding the glass crystal on the surface thereof opposite the projection whereby the crystal is clamped between the projection and the ring.

Description

BACKGROUND

1. Field of the Invention

The invention relates to structure for removably mounting a watch crystal for a water-proof watch, and particularly a structure which avoids any adhesive connection between the crystal and the mounting structure.

2. Prior art

It is well known to mount a crystal of glass or transparent plastic material on a support structure by means of an adhesive layer.

Specifically, a glass crystal is secured at its periphery to a ring by means of an adhesive and the ring is engaged with a case by a bezel, a gasket being disposed between the ring and the case.

In this construction, the adhesive is utilized to secure the glass crystal and to provide a water-proof connection between the glass crystal and the ring and thereby the adhesive has to be strong and reliable.

Accordingly, it is necessary to apply the adhesive over a relatively wide extent. However, this is unsightly because the applied adhesive is externally visible through the transparent glass crystal. Furthermore, any unsightly adhesive forced out during the attachment thereof to the ring must be removed. Additionally, it is necessary for proper control of the adhesive joinder to effect a number of operations.

When a broken or cracked crystal is to be replaced, it must be replaced together with the ring which is adhesively secured thereto. This is relatively high in cost in comparison with the cost of the crystal alone.

SUMMARY OF THE INVENTION

An object of the invention is to provide a mounting structure for a crystal of a water-proof watch which avoids the need for any adhesive between the crystal and the mounting structure thereby obviating the deficiencies associated therewith.

The invention contemplates a crystal mounting structure for a water-proof watch comprising a case, a bezel mountable in said case, and a crystal having an outer periphery disposed within said bezel. The bezel includes a projection overlying said crystal and having a diameter less than the outer diameter thereof. A first sealing member is interposed between said crystal and said bezel and a second sealing member is interposed between said bezel and said case. A ring is disposed between said case and said crystal on the side of the crystal opposite the engagement thereof with said projection in order to clamp the crystal between the ring and the projection on the bezel.

According to the invention, the crystal freely rests on the ring without any adhesive therebetween.

The sealing members can be received in respective recesses in the bezel and project from opposite sides thereof.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a cross-sectional view of the mounting structure at the outer periphery of a glass crystal of a watch according to the prior art, and

FIG. 2 is a corresponding cross-sectional of one embodiment according to the invention.

DETAILED DESCRIPTION

Referring to FIG. 1 therein is seen a crystal 1 of glass or suitable transparent material which is mounted on a ring 2 and secured thereto by a layer of adhesive 4. The ring 2 is secured to a case 6 by means of an annular bezel 3. The case 6 may be part of the watch housing or a ring secured thereto. A gasket 5 is interposed between ring 2 and case 6.

Since only the adhesive layer 4 serves to secure the glass crystal in place while also furnishing a water-proof seal between the crystal and the ring 2, the adhesive must be strong and reliable. The adhesive must be applied over a relatively wide extent and this mars the appearance since the adhesive is visible beneath the crystal. Moreover, any adhesive forced out between the crystal and the ring during the mounting operation must be removed as it is unsightly. Furthermore, in order to properly bind the parts with the adhesive, careful control and a number of operations are required. Additionally, when the crystal 1 is replaced, it must be replaced with the ring 2 secured thereto which is costly.

With reference to FIG. 2 showing an embodiment according to the invention, therein the crystal is shown at 7 and numeral 8 represents the bezel. A projection 8a is formed on the upper portion of the bezel and the projection has an inner diameter slightly smaller than the outer diameter of the crystal 7. The bezel includes an engaging portion 8b at its lower end with an inclined face for engaging a corresponding inclined face of a slot formed in case 9.

A sealing member 10 is received in a recess in the bezel for being interposed between the outer periphery of the crystal and the inner periphery of the bezel 8, and a sealing member 11 is received in a corresponding recess in the bezel for being interposed between the case 11 and the bezel 8. These sealing members are elastic members made of synthetic rubber, synthetic resin or soft metal. A ring 12 is disposed between the lower surface of the crystal and the case 9 within the bezel 8. The ring 12 may be forced into the bezel 8 with interference.

A water-proof condition is established between the crystal and the bezel by the sealing member 10, and a water-proof condition is established between the bezel and the case by the sealing member 11. These sealing members are compressed in the diametral direction. The crystal 7 is held by and between the upper projection 8a of the bezel and the ring 12. It is held steadily by the projection 8a against upward forces and by the ring 12 against downward forces. The bezel 8 is secured to the case by its engaging portion 8b. As described, the portion 8b has an inclined face in contact with the case and this serves to enhance the engagement therebetween and resist upward movement of the bezel. When the crystal is installed in place its upper surface is flush with the surface of bezel 8.

The assembly of the structure is as follows:

The sealing member 10 is initially secured in the recess in the bezel 8. The crystal 7 is inserted into the bezel in the direction from the engaging portion 8b, namely by being inserted upwardly. Then, sealing member 11 is mounted in the corresponding recess in the bezel 8. Thereafter, the ring 12 is mounted on the case 9, and the bezel with the crystal and the two sealing members is secured to the case by insertion of its engaging portion 8b into the slot of the case to effect engagement between the inclined faces thereof.

The crystal is securely and reliably held in place against upward removal by contact with the projection 8a of the bezel and the ring 12 holds the crystal and prevents downward displacement thereof. Moreover, the bearing surface of ring 12 is not as wide as the conventional adhesive layer. Accordingly the external appearance around the periphery of the crystal can be kept simple. Moreover, the crystal bears against a relatively narrow planar surface of the ring 12 and the ring has oppositely sloped surfaces at the inner and outer edges of the planar surface.

When the parts are assembled, they are merely interconnected in turn quite easily, requiring no environmental control as required when using an adhesive.

When a broken or cracked crystal is to be replaced, the crystal alone can be replaced at relatively lower cost than the arrangement where the crystal is adhesively secured to the ring and they must be replaced together.

In the above description, the sealing member 11 between the bezel and the case is compressed in the diametral direction, however, this sealing member may be compressed in the vertical direction to obtain the same effect.

Claims

What is claimed is:

1. Crystal mounting structure for a water-proof watch comprising a case, a bezel mountable in said case, a crystal having an outer periphery disposed within said bezel, said bezel including a projection overlying said crystal and having a diameter less than the outer diameter thereof, a first sealing member interposed between said crystal and said bezel, a second sealing member interposed between said bezel and said case, and a ring disposed between said case and said crystal on the side of the crystal opposite the engagement thereof with said projection.

2. A structure as claimed in claim 1 wherein said bezel is provided with a recess for said first sealing member.

3. A structure as claimed in claim 1 wherein said bezel is provided with a recess for said second sealing member.

4. A structure as claimed in claim 1 wherein said crystal freely rests on said ring in non-adhered manner.

5. A structure as claimed in claim 1 wherein said bezel includes a second projection having an inclined face engageable with said case.

6. A structure as claimed in claim 1 wherein said bezel has inner and outer surfaces and said sealing members are supported by said bezel and respectively project from said inner and outer surfaces.

7. A structure as claimed in claim 1 wherein said case has a notch and said ring includes a projection fitting into said notch.

8. A structure as claimed in claim 1 wherein said bezel has an upper surface which is substantially flush with the upper surface of the crystal.

9. A structure as claimed in claim 1 wherein said ring has a flat planar surface on which the crystal rests.

10. A structure as claimed in claim 9 wherein said flat planar surface has opposite edges, and said ring has oppositely sloped surfaces at said opposite edges of said ring.