US3545198A - Wristwatch case - Google Patents

Description

R. LOFTUS WRISTWATCH CASE 5 Sheets-Sheet 1 W Mm Dec. 8, 1970 Filed Nov.

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United States Patent 3,545,198 WRKSTWATCH CASE Richard Loftus, London, England, assignor to Old England Watches Limited, London, England Filed Nov. 5, 1968, Ser. No. 773,432 Claims priority, application Switzerland, Nov. 6, 1967, 15,468/67; Oct. 18, 1968, 15,640/68 Int. Cl. G041) 37/08 US. C]. 5890 11 Claims ABSTRACT OF THE DISCLOSURE A Watchcase comprising an upper and a lower cover each having a radially protruding rib, the ribs mating with each other along a common interface and being secured together, a bracelet having a bead portion which grips about said ribs.

The present invention relates to a highly simplified Watchcase construction which is particularly applicable to Wristwatches in regard to which there is provided a particularly simple means for attaching the bracelet to the case.

It is Well known to attach the bracelet, i.e., the wristband, to the Watchcase by means of horns, lugs, loops, etc., which protrude from diametrically opposite portions of the case. Of recent times, however, various other expedients have been adopted or proposed for the purpose of simplifying and reducing the cost of the means whereby the bracelet is attached to the case, such ex pedients having been applied particularly to metal cases of superior quality.

For example, it is known to attach the bracelet ends in thickened portions of the case back. This particular expedient, however, results in a Watchcase of increased thickness without the construction thereof being simplified to a material degree. Cases are also known which comprise two detachably fastened parts which, when assembled, define a chamber in which the watch movement is housed and between which the bracelet portions are fastened. Such cases, however, cannot be watertight and they are susceptible to becoming accidentally opened under the action of transverse forces acting upon the bracelet.

It is an object of the present invention to provide a Watchcase construction incorporating bracelet attachment means which is significantly simpler and less expensive to produce than heretofore known cases.

It is a further object to provide such a construction and which results in a perfectly watertight case.

It is a further object to provide such a construction without adding to the case thickness.

Other objects are those which are inherent in the following description of a preferred embodiment with reference to the accompanying drawings where:

FIG. 1 is a sectional view along a diametrical axis of the case which coincides with the longitudinal axis of the bracelet;

FIG. 2 is a plan view of the case and bracelet shown in FIG. 1;

FIG. 3 is a sectional view analogous to FIG. 1 of a case according to a second embodiment of this invention;

FIG. 4 is an enlarged sectional view showing a detail of the case of FIG. 3;

FIGS. 5 and 6 are respectively a plan view and a side elevation view on a reduced scale of the watch shown in FIG. 3.

In summary, the objects of the invention are realized through the provision of a Watchcase constructed in two parts joined together by mating portions which project Patented Dec. 8, 1970 ice" outwardly from opposite ends of each and which constitute elements for attaching respective ends of the bracelet to the case.

With reference to the accompanying drawings, the movement 1 includes a pillar plate having a peripheral threaded portion 2 which protrudes to a substantial extent radially from the movement side plate. A dial 3 overlies the pillar plate and its diameter is equal to that of threaded portion 2. Minute and hour hands 4 and 5 rotate above the dial on respective coaxial staffs which protrude upwardly from the movement 1 through the center of the dial.

The movement 1 need not be described in greater detail for purposes of understanding this invention. It is contemplated, however, that the movement be of relatively inexpensive type.

The movement 1 is enclosed in a case which consists of a back cover 6 and a top cover 7 both of which are preferably of plastic material and easily produced by simple known plastic molding techniques. Top cover 7, which constitutes the watch glass must be transparent in order to permit viewing of the dial while back cover 6 may be metalized on its outer or inner surface in order to give it the appearance of conventional metal cases.

The covers 6 and 7 each includes a vertical circumferential sidewall from which radially extends an outer peripheral rib 8 and 9, respectively, which extends completely around the cover, each rib being semi-circular in cross section with the fiat face thereof mating with the fiat face of the other rib along a common interface. The sidewalls each includes a circumferential recess 10 and 11 which, when the covers 6 and 7 are assembled together, defines a circumferential groove along the interior of the case into which fits the outer circumferential portion 2 of the pillar plate and the corresponding overlying portion of dial 3 whereby the movement and dial are secured within the case.

Preferably, the covers 6 and 7 are secured to each other by heat sealing (Welding) along the joint formed between the respective ribs 8 and 9 although other securing techniques are also applicable. Heat sealing constitutes a particularly simple form of seal and also one whichis very effective as to watertightness.

A not shown winding and setting member may extend through cover 6. For example, this member may com prise a conventional crown and Winding stem extending laterally from the case. Said crown can be mounted on a tube fastened to cover 6. However, the winding and setting member could also be concealed in cover 6 and arranged to actuate an element of the movement located near cover 6.

The bracelet 12, according to the invention, is of single piece construction having a central opening defined by C-ring bead 13 which opening circumferentially surrounds the case. The bracelet may include separable not shown outer ends such as a leather strap type bracelet having a buckle, etc., at its outer ends, or it may be continuous along its entire length such as resilient band type bracelet. In any event, the inner ends of the bracelet will be in the form of a continuous annular bead 13 which defines an inner groove 14 of a cross section corresponding to the outer cross-sectional configuration of ribs 8 and 9. In this regard, it will be noted that while ribs 8 and 9 have been disclosed as being semi-circular, they could conform to any arcuate shape which may be the equivalent of circular while still satisfying the purposes of this invention.

It is seen, therefore, that ribs 8 and 9 are tightly fitted within groove 14 whereby a secure attachment between bracelet 12 and case 6, 7 is achieved. Bracelet 12 is preferably also of plastic material.

The fastening of the case to the bracelet can be effected by elastically deforming the bead 13 so as to cause its two sides to pass over the ribs 8, 9 but it may also be effected by folding the two parts of the bead 13 while in hot condition over the ribs 8, 9, which operation can also be combined with the welding of the ribs 8 and 9 together. There is thus obtained a very rapid attachment of the bracelet described.

In other embodiments one could also contemplate effecting the fastening of the bracelet to the case by hookshap'ed metal elements engaged on the ribs 8, 9 but not extending over its entire length, said elements being connected to the two branches of the bracelet. However, the embodiment described has the advantage that the joint between the two ribs 8 and 9 is entirely concealed by the bead 13. Furthermore, the elasticity of the bracelet, and the fact that the bead 13 completely surrounds the case, provides a certain amount of protection against shocks.

In FIG. 3, there is shown a watch movement 31 of circular shape on whose pillar plate there is fastened a dial 32 which substantially extends radially beyond the outer periphery of the movement. This dial is flat, but, in another embodiment, it should also be curved. The dial 32 is preferably of metal in this embodiment since, as will be seen, it functions to fasten the movement within the case; however, in another embodiment, this fastening could also be effected with the periphery of the pillar plate.

The movement 31 is equipped with three indicator hands 33 which rotate about the movement center over the dial.

The watch furthermore comprises a case of circular shape, as is the movement, which case is formed of two covers 34 and 35 connected to each other along their mating peripheries. These two covers are of rigid plastic which is capable of being shaped by molding, is heat-scalable and is transparent.

The lower cover 34 which contains the movement 31 could, as a variant, be made of an opaque material or could be made translucent by the incorporating for in stance of a colorant. With respect to the upper cover 35, at least its central portion which acts as watch glass is transparent. The cover 34 is molded to provide a lateral sleeve element 36 within which there is embedded a tube 37. The inner space defined by the cover 34 is adjusted to the shape and dimensions of the movement 31 so that the latter fits exactly within the case. The protruding dial 32 will then rest on a peripheral shoulder of annular shape, which shoulder defines the uppermost plane of cover 34. In order to permit the movement to be placed into the case, the movement is provided with a winding stem in two parts, the outer part 39 of which is seen in FIG. 3. On this part 39 there is fastened a crown 40 equipped with a sealing means 41 which is fitted around the end of the tube 37 after the movement has been put in place and the stem part 39 has been introduced radially into the tube 37 and its inner end hooked onto the inner part of the stern.

In order to close the watch after the movement 31 has been put in place, the upper cover 35 is placed on the cover 34 and these two covers are heat-sealed (welded) to each other.

As shown in FIG. 4, the cover 34 includes a ridge 42 of triangular profile which protrudes from the shoulder 38 axially beyond the thickness of the dial 32. Cover 35 includes a flat annular shoulder 43 within which is formed a groove 44 of a width greater than that of the ridge 42 and of a depth less than the axial height of the latter. The profile of this groove, as shown in FIG. 4, is shaped so that when the two covers are placed one on the other, the top of the ridge 42 rests in the inner edge of a dihedron formed by the lower parts of the two sides of the groove 44.

In order to close the case, it is sufiicient to carry out a welding (heating-sealing) operation during which the covers 34 and 35 are pressed together by annular members one of which presses against the peripheral annular protrusion 45 which circumscribes cover 34 while the other presses against the similarly shaped protrusion 46 which circumscribes cover 35. Under the effect of the heating, the ridge 42 is deformed and the material of which it is composed is bonded by adherence to the material which forms the sides of the groove 44. In FIG. 4- it will be noted that the outer radial portion of the shoulder 43 is of an axial height slightly different than the inner radial portion so that it is this inner radial portion which comes into contact with the shoulder 38 when the two parts are pressed against each other. An annular recess 47 is formed along the inner edge of the shoulder 43 for receiving therein the outer edge of the dial 32. It is sufficient for the height of this recess to correspond to the thickness ofthe dial so that with the aforementioned welding (heat-sealing), there is obtained a rigid attachment of the movement to the case.

The carrying out of the welding or heat-sealing is effected in accordance with one of the known customary techniques.

By virtue of the welding of the rib 42 in the groove 44, the case is sealed in waterproof manner. If necessary, the two covers of the case may be separated by wedging a blade between the two shoulders 43 and 38. However, it is then necessary to replace covers 34 and in order to reseal the movement.

In another embodiment, the profiles of the rib 42 and of the groove 44 could be similar and the two covers of the case could be assembled by glueing, the glue being applied between the faces of the rib and the sides of the groove.

The annular protrusions and 46 which extend along the periphery of the covers 34 and 35 also serve as fastening means for a bracelet 48. Between them these two protrusions define a groove 49 of rectangular profile which extends along the outer side face of the case. As for the bracelet 48, it is also formed by molding from flexible plastic material and comprises a central portion 50 of ring shape, the profile of which has an upper lip 51, a lower lip 52 and a central protrusion 53. The manner of attaching the bracelet to the case can be noted from FIG. 3. The lips of the central portion 50 engage on opposite sides of protrusions 45 and 46 when the central protrusion 53 engages in the groove 49. At the location of the winding stem, the central ring of the bracelet has a notch 54. The use of plastic to form the bracelet in the manner of attachment described makes it possible to produce this part by mass production means while permitting considerable variation in its outer appearance.

In the embodiment shown in FIGS. 5 and 6, the bracelet 48 has in its two arms slits 55 arranged in a herringbone pattern. Furthermore, to its two ends there are fastened elements of synthetic fabric 56 and 57 one of which is a hook fabric element and the other an eye fabric element. Applying these two pieces of fabric against each other provides a hooking together of the bracelet parts. These fabric parts may for instance be of the type known on the market under the name Velcro. They may be fastened by any suitable means to the ends of the bracelet.

As can be seen in FIG. 3, the profile of the central ring 50 of the bracelet is such that said ring extends higher in height than the upper level of cover 35. It, therefore, protects the glass against the danger of scratches and due to its ability to deform it also protects the movement against shocks.

It is to be understood that the invention has been described only with reference to a particular mode of realization and that it is susceptible to being practised in accordance with various modifications, equivalents, substitutions, etc., without departing from the spirit and scope I of the invention as herein presented.

What is claimed is: 1. A wristwatch comprising two mating covers which define an enclosure for housing a movement therein, a rib extending radially from each said cover around the entire periphery thereof and mating along a common annular interface with each other, said ribs being tightly joined together and a wristband attached to said case by means of an annular C-ring which grippingly engages about the outer surface of said ribs.

2. The case of claim 1, said ribs extending completely along the outer periphery of said covers, each said cover with its respective said ribs being of one-piece construction and of weldable plastic material, the ribs being welded together along said interface.

3. The case of claim 1, said covers defining an inner circumferential groove between respective axially spaced apart portions thereof, a watch movement in said case having a radially extending circumferential portion extending into said inner groove and thereby being secured within said case.

4. The case of claim 1, wherein one of said ribs includes a hollow radially extending portion, a metal tube embedded in said hollow portion and extending radially outwardly thereof, and a winding stem crown rotatably mounted over the outwardly extending portion of said tube with a sealing means fitted between said crown and said tube.

5. The case of claim 1, said ribs defining two flat axially opposed annular surfaces and a radially inwardly recessed outer peripheral groove between said surfaces, said bracelet in cross section being shaped to comprise axially opposed radially inwardly directed annular lips which grip about said surfaces and a radially inwardly directed central portion received Within said peripheral groove.

6. The case of claim 1, said bracelet comprising respective free opposite ends, said bracelet being of a flexible plastic material and including hook-and-eye fabric elements respectively along opposite end portions thereof for detachably fastening said end portions together.

7, The case of claim 1, said ribs together defining an 6 arcuate outer outline in cross section, said bracelet bead defining a groove into which said ribs are fitted, said bead embracing substantially the entire outer cross-sectional surface of said ribs.

8. The case of claim 7, said ribs defining a circular outer outline.

9. The case of claim 1, a one of said ribs including an axially recessed annular groove and the other of said ribs including an axially protruding annular ridge which extends into said annular groove.

10. The case of claim 9, said covers being of weldable plastic material and said ridge being heat-welded to the walls of said groove.

11. The case of claim 9, said covers comprising contiguous annular radial surfaces a one of which extends radially inwardly beyond the other to form an annular shoulder, a recess along the inner edge of the other of said surfaces forming an annular groove with said shoulder, a watch movement in said case having a radially extending circumferential portion extending along said shoulder and into the last-mentioned groove whereby said movement is secured to said case.

References Cited UNITED STATES PATENTS 1,195,299 8/1916 Wachter 5888WUX 2,344,422 3/ 1944 Sickinger 58--88WSTC FOREIGN PATENTS 822,169 10/1951 Germany 5 890A 218,928 1/ 1942 Switzerland 5890A 246,727 1/ 1947 Switzerland 5 890A RICHARD B. WILKINSON, Primary Examiner G. H. MILLER, JR. Assistant Examiner Us. 01. X .R, 58-105

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