Horology: time measuring systems or devices – Cases – With movement ring details
Reexamination Certificate
1999-10-25
2001-04-10
Miska, Vit (Department: 2859)
Horology: time measuring systems or devices
Cases
With movement ring details
C291S027000
Reexamination Certificate
active
06213635
ABSTRACT:
FIELD OF THE INVENTION
The present invention concerns a manufacturing method for a watch case including a middle part, a back cover and a support ring intended to support the internal elements of the watch, wherein the middle part and the support ring are manufactured separately, then the support ring is fixed to the interior of the middle part via a element made of elastomeric material. The invention also concerns a watch case able to be obtained via this method.
BACKGROUND OF THE INVENTION
In the watch and more particularly the wristwatch field, arranging certain elements of the watch such as the movement, the dial or the bezel in a support ring often called the casing ring, which is inserted in the middle part of the watch, is known, as described for example in Swiss Patent No. 681 127.
In the case of a water resistant watch, inserting a plurality of sealing gaskets made of elastomeric material in the vicinity of the back cover, around the stem and watch crystal is known.
Although the machining operations inside the middle part are simplified by the insertion of the casing ring, difficulties remain which have never been satisfactorily resolved. In particular, in order to prevent any angular displacement between the casing ring and the middle part, the latter must, in the prior art, be provided with one or more holes receiving as many catches of the support part or screws in the case of the aforecited document. The problem of the inner dimensions of the middle part, which have to be fitted to the casing ring, thus remains intact.
This problem is particularly acute when the middle part is made of hard materials, for example ceramic materials or hard metal. On the one hand, such parts are generally manufactured by moulding and sintering, thus undergoing dimensional variations which do not allow precise final dimensions to be obtained from the unworked parts. On the other hand, inner machining of these hard parts is very difficult and expensive. In addition to the problem of fitting the casing ring inside the middle part, there is the problem of proper positioning of the ring and thus the clockwork movement, in particular the centring thereof, with respect to a middle part whose unworked or even final dimensions are imprecise.
Elastically suspending the movement in a watch case by means of an elastic ring made of rubber placed between the middle part and an inner metal ring intended to support the movement is known, in particular from French Patent No. 898 248. The rubber ring is pre-manufactured with predetermined dimensions, then inserted in the middle part, to which it is fixed using an adhesive material. It can thus be assembled to the ring by adhesion. This ring rests against the bezel and the back cover of the case to assure sealing and further includes a tubular lateral extension which acts as sealing gasket for the winding stem. However, a ring of this type having predetermined dimensions does not allow variations in the dimensions of the middle part to be compensated, or only very locally. Further, such compensation is not provided in the aforecited Patent.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the aforementioned problems, by providing a simple and economical manufacturing method, which allows proper accurate positioning of the movement in the middle part of the watch case and compensation of any variations in the dimensions of the middle part, in particular by avoiding machining operations of the interior of the middle part. Another object of the invention is to facilitate making of the means for sealing the watch case.
The invention therefore concerns a method of the type defined in the preamble, characterised in that at least a portion of the element made of elastomeric material is formed by moulding in a gap between the middle part and the support ring, during which step the support ring is held in a desired position within the middle part by means of at least one core which is positioned with respect to one or more reference surfaces of the middle part.
The elastomeric nature of the material moulded in the gap between the support ring and the middle part allows one to be free of previously very strict constraints, as regards shape and machining to the desired dimensions within the middle part. In fact, no machining of the interior of the middle part is necessary on the surfaces which will be covered with the elastomeric material, and it is even advantageous for these surfaces to be rough or unworked, which improves adherence. The outer dimensions of the support ring pose fewer problems, since this part is generally machined if it is made of metal, or moulded with sufficient accuracy if it is made of plastic material.
An important aspect of the invention is that the support ring, in particular when it is a casing ring, does not need to be positioned by resting against inner surfaces of the middle part, in particular the surfaces which will be in contact with the elastomer. This allows other locations to be selected as reference surfaces for positioning of the support ring, for example outer surfaces of the middle part which would have in any case to be machined or polished, or surfaces which determine the external appearance of the watch, such as the snap for the crystal or back cover.
The element made of elastomeric material is preferably overmoulded in said gap by injection, transfer or compression. This element may include at least one portion which is set in place after the overmoulding step.
The element made of elastomeric material can constitute a sealing gasket between the middle part and the back cover of the case, and/or between the middle part and a control stem passing through the middle part, and/or between the middle part and a crystal of the case.
The overmoulded elastomeric material is preferably selected so that it adheres to the material of which the middle part is made.
REFERENCES:
patent: 5033035 (1991-07-01), Affolter
patent: 310877 (1956-01-01), None
patent: 544 960 (1974-01-01), None
patent: 634 454G (1983-02-01), None
patent: 2 017 168 (1970-05-01), None
patent: 2 463 437 (1981-02-01), None
Bach Michael
Bolzt Sébastien
Carrard Bertrand
Meyrat Clement
Savy Philippe
Biwi S.A.
Goodwin Jeanne Marguerite
Griffin & Szipl, P.C.
Miska Vit
LandOfFree
Method for making a watch case does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for making a watch case, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for making a watch case will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2485799