US3618312A

US3618312A - Watch crown

Info

Publication number: US3618312A
Application number: US820190A
Authority: US
Inventors: William W Macchia; Cyril F Seymour
Original assignee: Timex Corp
Current assignee: Timex Group USA Inc
Priority date: 1969-04-29
Filing date: 1969-04-29
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09
Also published as: DE2020358A1; FR2096716B1; DE2020358C3; JPS4825948B1; GB1269874A; DE2020358B2; FR2096716A1

Abstract

A WATCH CROWN FOR A WATERPROOF WATCH INCLUDES A METAL OR PLASTIC CROWN BODY HAVING AN INTERIOR CAVITY. A TUBULAR PENDANT PROTRUBING FROM THE BEZEL PORTION OF THE CASE OF THE WATCH IS ADAPTED TO FIT WITHIN THE CAVITY OF THE CROWN BODY. WATERPROOF SEALING IS OBTAINED BY THE USE OF A MOLDED ELASTIC GASKET WHICH IS HELD IN PLACE IN THE CROWN BY A RING WHICH IS FIXED TO THE CROWN BODY. THE GASKET, IN CROSS-SECTION, HAS A FLAT WASHER-LIKE PORTION AND, INTEGRAL THERETO AT THE INNER DIAMETER OF THE WASHER, A RAISED FLANGE-LIKE PORTION HAVING AN ARCUATE INNER FACE.

Description

United States Patent fice 3,618,312 Patented Nov. 9, 1971 3,618,312 WATCH CROWN William W. Macchia, Naugatuck, and Cyril F. Seymour, Middlebury, Conn., assignors to Timex Corporation Filed Apr. 29, 1969, Ser. No. 820,190 Int. Cl. G04b 37/08 US. C]. 58-90 B 3 Claims ABSTRACT OF THE DISCLOSURE A watch crown for a waterproof watch includes a metal or plastic crown body having an interior cavity. A tubular pendant protruding from the bezel portion of the case of the watch is adapted to fit within the cavity of the crown body. Waterproof sealing is obtained by the use of a molded elastic gasket which is held in place in the crown by a ring which is fixed to the crown body. The gasket, in cross-section, has a fiat washer-like portion and, integral thereto at the inner diameter of the washer, a raised flange-like portion having an arcuate inner face.

DESCRIPTION The present invention relates to horology and more particularly to a crown for a waterproof watch.

It has generally been though desirable that a watch should be waterproof. Watches, even when treated with care, occasionally may become wet, for example, due to rain or accidental immersion. When watches were a luxury item, they Were treated with considerable care. Wrist watches were removed from the wrist before washing the hands. However, wrist watches are no longer considered a luxury item and they are often treated carelesslythey are left on when washing the hands, when going out in the rain, or even when swimming or bathing. 'People nevertheless expect that their watches will continue to operate, despite the adverse treatment to which they subject them. There is a demand that even relatively lowpriced watches be waterproofed.

The demand for low-priced waterproof watches has presented difiiculties to watch manufacturers. Some of the devices which provide waterproofness in a watch are too expensive to be utilized in low-priced watches. On the other hand, there have been proposed various waterproofing methods which, although low in cost, are impractical or only operate for a short time and thereafter cease to protect the watch,

The problem of waterproofing inexpensive watches has been particularly acute in obtaining a satisfactory waterproof watch crown. The watch crown is used in a mechanical watch to wind the mainspring and to set the hands. In winding the mainspring the watch crown is connected to a winding staff, which is co-axially within a tubular pendant fixed to the bezel of the watch and the winding staff is turned upon rotation of the crown. The crown is pulled outward away from the body of the watch and rotated in order to set the hands.

The watch crown sealing element must perform various functions. It must keep the watch waterproof during the normal position of the crown, that is, with the crown pressed inwardly against the watch body. It must also prevent leakage of water into the pendant when the crown is pulled outward in order to set the hands. In addition, the waterproofing mechanism must permit the crown to rotate in relationship to the pendant, both in its winding and hand-setting positions. It is important that the rotation of the crown not cause the waterproofing seal to become worn out; for, if that seal should fail, Water may flow from outside of the crown, through the pendant and into the watch, harming or destroying its mechanism.

It is the objective of the present invention to provide a crown for a watch, which crown provides a waterproof seal, is relatively inexpensive, and may be assembled with a minimum of labor.

It is a further objective of the present invention to provide such a crown which does not readily wear out with use, which provides a waterproof seal setween the crown and the pendant, and yet permits rotation of the crown.

In accordance with the present invention a watch crown is provided. The crown includes a plastic or metal crown body, preferably having conventional outer teeth. The crown body has an inner cavity. A pedestal, integral with the body, is positioned at the top of the cavity and protrudes into the cavity. The pedestal has a bore for an interference fit, or other attachment means, so that it may be fastened, either permanently or removably, to the winding stem of the watch. The cavity is adapted to fit over the tubular case pendant, which protrudes from the bezel of the watch. An annular elastic gasket is held within the cavity by a metal or plastic ring, the ring being staked, glued or otherwise joined to the crown body. In cross-section, the gasket has a bottom flat washer-like portion and a raised flange-like portion at the inner diameter of the washer-like portion. The flat washer-like portion of the gasket is firmly positioned between the top surface of the ring and the bottom of a ledge formed in the crown body. The flange-like portion, on its inner surface, is curved but on its outer surface is flat. The outer surface of the flange-like portion is held against a circumferential wall of the cavity of the crown body. The curved inner surface of the flange portion of the gasket, when the crown body is in its position on the pendant of the watch, is compressed against the pendant. The gasket is firmly held within the crown body even when the crown body is removed from the watch. It will not fall out of the crown body and may be exactly centered within the cavity of the crown body. The curved surface of the gasket permits rotation of the crown body without binding. At the same time the gasket provides an excellent seal against water.

Other objectives of the present invention will be apparent from the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side cross-sectional view of the watch crown of the present invention in its position on the watch;

FIG. 2 is a side view, the left half in section and the right half in plan, showing the crown removed from the watch;

FIG. 3 is a sectional view of the gasket ring; and

FIG. 4 is a bottom plan View of the watch crown of the present invention.

As shown in FIGS. 1 and 2, the watch crown of the present invention includes a crown body 1, preferably made from metal or plastic. The body 1 has an exterior set of conventional external teeth (knurlings) 2 and are used to grip the crown. A cavity 3 is formed within the body 1. The body has a hollow pedestal portion 4 which protrudes into the cavity 3. The pedestal portion 4 has a bore 5 which is adapted to grip the external teeth 6 of the winding stem 7. Alternatively, the bore of pedestal 4 may have internal screw threads adapted to be screwed to the exterior screw threads of the winding stem. The setting stem 7 is a round staff which is rotatable within the tubular pendant 8. The tubular pendant 8 is integral with, and protrudes from, the bezel or other portion of the watch case. A ring 10, in the form of a metal or plastic washer (a fiat annular shape) is attached to the crown body 1. The attachment may be, as shown, by staking a lip 11 of the crown body over the ring 10 or alternatively by adhesive or other joining means. The flat outer diameter wall of the ring may be close to, or rest against, the internal wall portion 12 of the crown. The gasket 13 is in the form of a ring. Preferably the gasket is made of a moldable elastic material, for example, the plastic resin polyurethane. The gasket includes a bottom washer-like portion 14 and an upright flange portion 15. The bottom portion .14, which is in the form of a fiat washer, is held between the upper (internal) face of the ring 10 and the downwardly inclined ledge 17 of the crown body. The flange-like portion 15 of the gasket has, at its inner diameter, a curved arcuate face 16. The curved face 16 presents the same type of low resistance surface to the pendant 8 as would be presented by an O ring. However, the gasket 13 presents the advantage, as compared to an O ring, of being firmly held in place within the crown body. Due to its being compressed between the ledge 17 and the upper surface of the ring 10, the gasket prevents water leakage between the ring and the crown.

We claim:

1. A waterproof watch crown comprising a crown body having an interval cavity, said crown body being adapted to fit over a watch case tubular pendant, said crown body having a tubular portion within said cavity extending outwardly from the top of the cavity in the crown body to fit within the said case pendant and to be attached to the winding stem of a watch; an annular molded elastic gasket within said cavity adapted to be compressed between said crown and said pendant to form a seal; and an annular hard washer having an inner round hole fitted about the pendant and being fixedly attached at the bottom thereof to a 'lower portion of said crown to partly cover said cavity and retain said gasket within said cavity, said engagement of the pendant with the inner round hole preventing adverse effects on the seal from side loading of the crown; wherein said gasket viewed in cross-section has as integral portions a bottom flat Washer-like portion and a flange-like upper portion at the inner edge of said fiat portion, said flange-like portion having an arcuate inner face and a fiat outer face; and wherein said washerlike portion is clamped tightly between said hard washer and said crown body to form a seal.

2. A watch crown as in claim 1 wherein the internal wall of said cavity in said crown body forms a first enlarged cylindrical cavity portion and, above said first portion, a second smaller cylindrical cavity portion, the walls forming between them a ledge, said gasket, at its washer-like portion, being clamped between said ledge and the top of said hard washer to form a seal.

3. A watch crown as in claim 1 wherein the hard washer is of metal and staked in place within the crown.

References Cited UNITED STATES PATENTS 2,771,734 11/1956 Morf 58-90 B 2,784,547 3/1957 Waldman 5890 B 3,475,901 11/1969 Soguel 58--90 B FOREIGN PATENTS 1,204,013 1/ 1960 France 58-90 B 1,216,990 4/1960 France 5890 B 272,324 12/1950 Switzerland 5890 B RICHARD B. WILKINSON, Primary Examiner G. H. MILLER, JR., Assistant Examiner