US3500631A

US3500631A - Structure of cut-glass for wristwatch

Info

Publication number: US3500631A
Application number: US715340A
Authority: US
Inventors: Masayoshi Aoki
Original assignee: Seiko Instruments Inc
Current assignee: Seiko Instruments Inc
Priority date: 1967-03-24
Filing date: 1968-03-22
Publication date: 1970-03-17
Anticipated expiration: 1987-03-17
Also published as: CH424668A4; GB1164963A; CH497732A

Description

March 17, 1970 MASAYOSHI AOKI 3,500,631

STRUCTURE OF CUT-GLASS FOR ,WRISTWATCH Filed March 22. 1968 4 Sheets-Sheet 1 7/ F/ a. /A Q PRIOR ART 1 FIGJB PRIOR ART MASAYOSHI AOKI STRUCTURE OF CUT-GLASS FOR WRISTWATCH March 17, 1910 4 Sheets-Sheet 2 Filed March 22. 1968 FIG. 2A

PRIOR ART ,{5

B 2 G F T R A W F/G.2C

PRIOR ART Man}! 17, 1970 MASAYOSHI AOKI I 3 STRUCTURE OF CUT-GLASS FOR WRISTWATCH Filed March 22. 1968 4 Sheets-Sheet 3 F/G.3A 12mm;

F/G.3B

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March 1970 MASAYOSHI AOKI. 3,500,

STRUCTURE OF CUT-GLASS FOR WRISTWATCH Filed March 22. 1968 4 Sheets-Sheet 4 United States Patent 3,500,631 STRUCTURE OF CUT-GLASS FOR WRISTWATCH Masayoshi Aoki, Tokyo, Japan, assignor to Kabushlki Kaisha Daini Seikosha Filed Mar. 22, 1968, Ser. No. 715,340 Claims priority, application Japan, Mar. 24, 1967, 42/23,857 Int. Cl. G04b 39/00 US. CI. 5891 3 Claims ABSTRACT OF THE DISCLOSURE A watch crystal assembly for covering the faces of watches. The assembly includes an outer transparent member which is adapted to extend across and cover the face of a watch and an inner ring which is adaptedto engage the bezel of the watch and which has a surface visible through the outer member and formed with facets. As a result the thickness of the watch case need not be increased to accommodate the watch crystal and the facets can be formed in a simple inexpensive manner.

BACKGROUND OF THE INVENTION The present invention relates to watches.

In particular, the present invention relates to watch crystals.

There are many different types of watch crystals known in the art. It has become customary in many watches to provide the watch crystal at the region of its outer periphcry with a faceted surface which not only increases the decorative effect but in addition distributes the light around the watch face in such a way as to improve the visibility thereof. This invention relates particularly to this latter type of construction.

At the present time many watches which have crystals of this construction must have the thickness of the watch case increased in order to accommodate the crystal. Because the crystal is provided in the region of its outer periphery with the inner faceted surface, the crystal extends undesirably inwardly beyond the bezel, and in order to maintain the crystal at the required distance from the watch face it is necessary to make the watch case thicker.

Attempts have been made to improve this latter construction, but even these latter attempts are not entirely satisfactory because with the best known structures it is still necessary to form the facets on the watch crystal, thus resulting in an exceedingly expensive structure.

SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a watch crystal assembly which will avoid the above drawbacks.

In particular, it is an object of the invention to provide a watch crystal with a faceted peripheral region which can be manufactured at far less cost than has hitherto been possible.

Also, it is an object of the invention to provide a watch crystal with a faceted peripheral region which although inexpensively manufactured can have any desired combination of facets of any desired configuration to achieve whatever visual or decorative effects may be desired.

It is in addition an object of the present invention to provide a watch crystal which does not necessitate a thickening of the watch case in order to accommodate the crystal.

Thus, in accordance with the present invention the watch crystal assembly includes an outer transparent member which extends across and covers the watch face. An inner ring of the watch crystal assembly is visible 3,500,631 Patented Mar. 17, 1970 "ice through the outer member thereof and has a faceted surface which is visible through the outer member. Because this inner ring is a separate component of the assembly it is a simple matter to form the facets on the surface thereof which is visible through the outer member of the crystal assembly.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1A is a side view of a conventional watch crystal.

FIG. 1B is a top plan view of the crystal of FIG. 1A;

FIG. 10 shows the crystal of FIG. 1A in section mounted on a schematically illustrated Watch case;

FIG. 2A is a sectional elevation of another form of known crystal;

FIG. 2B is a top plan view of the crystal of FIG. 2A;

FIG. 2C is a schematic representation of the crystal of FIG. 2A mounted in a watch case;

FIG. 3A is a sectional elevation of a crystal assembly according to the invention; 3AFIG. 3B is a top plan view of the structure of FIG.

FIG. 3C schematically illustrates how the structure of FIG. 3A is mounted on a watch case; and

FIGS. 4A-4G respectively illustrate the various possible different configurations and combinations of facets which may be formed on the ring of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1A, it will be seen that the conventional cut-glass crystal 1 shown therein has along its inner peripheral surface an inclined, bevelled portion 1a, and this portion is faceted in any desired manner so that when looking downwardly upon the structure of FIG. 1A, the watch crystal will have the appearance indicated in FIG. 1B. This appearance is not only decorative but the brilliance of the illumination is also enhanced.

However, the structure of FIGS. 1A and 1B necessitates a bezel mounting as shown in FIG. 1C. Thus, referring to FIG. 10, it is to be noted that the bezel must be axially displaced from the watch face sufficiently to accommodate the crystal 1 which extends inwardly beyond the exterior grooved inner periphery of the bezel of the watch case 2. For this reason it becomes necessary to make the watch case 2 thicker than would otherwise be required. Moreover, the decorative and illumination effects which are achieved when the crystal of FIG. 1A is viewed by itself, as indicated in FIG. 1B, are not achieved in the assembly of FIG. 1C because the presence of the bezel detracts from the effects which are otherwise achieved with the crystal by itself. The decorative and visual effects which are achieved are interfered with and deteriorate because of the assembly of the structure with a bezel in the manner shown in FIG. 1C.

It has already been proposed to improve this latter construction of FIGS. lA-lC by providing a structure as illustrated in FIGS. 2A2C. Thus, as may be seen from FIG. 2A, the watch crystal shown therein has not only the outer face-covering portion 1, but also an outer peripheral flange 1b which is adapted to extend into engagement with the bezel. Surrounded by the flange 1b is an inner inclined or bevelled surface In which is directly formed on the interior of the crystal 1 and which has the facets, as indicated in FIG. 1B. Thus, there is no question that the structure of FIGS. 2A and 2B are superior to that of FIGS. 1A and 1B. The same visual and decorative effects are achieved. Moreover, when the crystal of FIGS. 1A and 1B is mounted on the watch case 2 as shown in FIG. 2C, the crystal does not extend inwardly beyond the outer peripheral bezel groove which receives the flange 1b in the manner indicated in FIG. 2C, so that the watch case 2 need not be thickened to accommodate the crystal of FIGS. 2A and 2B.

In this latter connection, if FIGS. 1C and 2C are compared and it is assumed that the total thickness of the entire watch in both cases is T, then it will be seen that the dimension T of FIG. 1C, representing the extent to which the crystal extends beyond the watch case, is less than the dimension T of FIG. 2C which represents the same dimension. It follows, therefore, that the watch case thickness T of FIG. 1C is greater than the watch case thickness T of FIG. 2C, and in fact it is quite clear that it is essential with the structure of FIGS. 1A and IE to provide a watch case 2 which has been suitably thickened to accommodate the crystal.

It is furthermore to be noted that although the bezel of FIG. 1C detracts from the visual and decorative effects which can be achieved with the crystal, this latter disadvantage also is eliminated with the construction of FIGS. 2A and 2B, since the bezel has no effect on the faceted surface 1a. Even though the entire crystal structure of FIGS. 2A and 2B is relatively thick, the decorative and visual effects do not diminish because of the clear transparency of the glass.

However, the construction of FIGS. 2A2C do not provide a satisfactory solution inasmuch as the design and workability of the glass available for the crystals of FIGS. 2A2C necessitate limitations. Because the facets are situated directly on the glass surface in the interior thereof in the manner indicated in FIG. 2A, the working of the glass can be carried out only with great difficulty and the nature of the facets is limited.

These drawbacks are avoided with the present invention which is illustrated in FIGS. 3A-3C.

Thus, referring to FIG. 3A, the watch crystal assembly of the invention illustrated therein includes an outer member 1 which is adapted to extend across and cover the face of the watch and which is made of a clear transparent material such as any suitable glass. However, the facets are not cut directly on the member 1 of FIG. 3A. Instead, the watch crystal assembly of the invention is provided with a separate inner ring 3 which has a faceted surface 3a visible through the outer member 1. The ring 3.is made of the same material as the member 1. This member 1 has at its outer periphery an inwardly extending flange surrounding the axis of the watch face and directly engaging the bezel in the manner shown in FIG. 3C. The separate ring 3 which is surrounded by and engages the exterior flange of the outer member 1 terminates in an inner face which is flush with the inner end face of the flange of the member 1 and which also engages the bezel in the manner shown in FIG. 3C. The faceted surface 3a on the other hand has an inner peripheral edge which is nearer to the watch face than the outer peripheral edge, this surface forming part of a cone whose apex is on the same side of the member 1 as the ring 3. Therefore, with this construction all of the advantages of the construction of FIGS. 2A and 2B are achieved at far less cost because it becomes possible to provide the facets on the surface 3A before the ring 3 is assembled with the member 1. At this time the surface 311 is readily accessible so that there are no difficulties in forming the facets and there are no limitations on the many different types of facets which can be provided. FIGS. 4A-4G illustrate various different possibilities, among many more, of the types and combinations of facets which can be very inexpensively provided with the watch crystal assembly of the invention.

Therefore, even though the crystal of the invention is formed of the separate components 1 and 3 which must be assembled together, nevertheless it is ossible to achieve the visual and decorative effects indicated in FIG. 3B and the assembly of the invention can be mounted on the watch case 2 without requiring the thickness of the latter to be increased inasmuch as the inner end surface of the outer peripheral flange of member 1 directly engages the bezel and is situated in the same plane as the inner end surface of the ring 3 which also directly engages the bezel.

It is to be noted that the rings 3 are not only manufactured separately from the members 1, but in addition a large collection of such rings not only of different faceted arrangements but also of different colors can be kept on hand to be assembled with the member 1 of the crystal assembly according to the tastes and requirements of a given purchaser.

What is claimed is:

1. A *watch crystal assembly for mounting on the bezel of a watch case comprising an outer member adapted to extend across and cover the face of a watch and formed with an inwardly extending, bezel-engaging flange along its outer periphery, and an inner bezel-engaging ring peripherally engaging said outer member flange and having a faceted, light distributing, upper surface visible through said outer member, said inner ring and outer member both being made of the same transparent material.

2. The combination of claim 1 and wherein said ring and flange both terminate in inner end faces which are in a common plane parallel to the plane defined by an inner bezel surface with which they engage.

3. The combination of claim 1 and wherein said faceted surface of said ring is situated at a face thereof which extends between an outer periphery of the ring and an inner periphery thereof, said faceted surface forming substantially part of a cone whose apex is situated in the same side of said outer member as said ring.

References Cited FOREIGN PATENTS 1,384,590 11/1964 France.

934,018 8/ 1963 Great Britain. 301,498 9/ 1954 Switzerland.

STEPHEN J. TOMSKY, Primary Examiner G. H. MILLER, 1a., Assistant Examiner U1 C KR. 4