US2867079A

US2867079A - Watch crown

Info

Publication number: US2867079A
Application number: US657698A
Authority: US
Inventors: Pfisterer Richard
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-08-17
Filing date: 1957-04-10
Publication date: 1959-01-06
Anticipated expiration: 1976-01-06

Description

Jan. 6, 1959 R. PFlsTERER WATCH CROWN Original Filed Aug. 17, 1954 /N VEN raz- /P/CHARD PF/STERER BY CMM/1 i A TTOR/VEKS United States Patent @nice Patented Jan. 6, 1959 WATCH CROWN Richard Psterer, Pforzheim, Germany Original application August 17, 1954, Serial No. 450,345, now Patent No. 2,849,854, dated September 2, 1958. Divided and this application April 10, 1957, Serial No. 657,698

7 Claims. (Cl. 58-90) The present invention relates to a crown for wristwatches and pocket-watches which are provided with an elastically -or resiliently suspended watch-work.

This application is a division of the application filed by same named inventor, filed August 17, 1954 and having a Ser. No. 450,345, Patent No. 2,849,854.

It is already known to avoid the strain on the winding shaft through the provision of a coupling part between the crown and the undivided winding-shaft, whereby the coupling part (which is rigidly connected to the winding shaft) nutatably rests against a spring. But crowns of this known type are not watertight, and can not be made watertight without serious disadvantages.

Contrary to this, the crown which the invention proposes to employ is so divised that the spring presses the coupling part (which lis rigidly secured to the windingshaft) onto the packing of the crown and thereby renders the crown watertight.

For this purpose, the coupling part (which is rigidly secured to the winding-shaft) is provided with a projecting rounded portion which rests in point-like fashion against a spring-plate or rubber-plate supported in the crown only with marginal portions. In this way an always uniform all-round pressure is constantly exerted on the packing. The pressure upon the packing is preferably exerted by a flange pressed by the spring down upon the shoulder of the crown which, according to the invention, is formed by a packing ring secured in its position within the crown by an outer metal ring.

Additional features and advantages of the invention will be understood from a consideration Iof the following detailed description taken in connection with the accompanying drawings, forming a part of this specification and in which several embodiments of the invention havev been shown by way of example.

In the drawings Fig. 1 is a bottom plan View of the crown of a watertight watch seen in the direction of the arrow I of Fig. 2;

Fig. 2 is a central vertical section of the crown on line II-II of Fig. 1;

Fig. 3 is a side-view, partly in section, of the crown mounted on the tube, on line IIl--III of Fig. l.

Referring now to the drawings in detail, a specific embodiment of this invention will now be described.

Screwed onto the winding-shaft 2 (Fig. 3) is the coupling 3. The coupling 3 has a flange 14 and a rounded portion 4 by means of which it is enable to nutate or reel on the spring plate 5 positioned above it in the crown 6. The spring-plate Sis pretensioned and urges the flange 14 of the coupling 3 against the shoulder or collar 12 of the crown 6. Arranged in the crown 6 beneath the spring-plate 5 is the ring 7 provided with drivers 8 (see Fig. 2). To these drivers 8 correspond notches 9 provided in the flange 14 Iof the coupling 3. There is so much clearance between the notches 9 and the drivers 8 (see Fig. 1) that the movability of the coupling with respect to the spring-plate 5 is not interfered with. The tube 10 of the watch extends into the gap 11 between the coupling and crown (see Fig. 12). The annular shoulder or collar 12 consists in the embodiment illustrated in the drawings of elastic material (rubber). It simultaneously serves as packing ring, and is secured in its position in the crown by means of the ring 13.

However, I wish to say that the invention is not confined to any strict conformity with the showing of the drawings, but may be changed or modified, so long as such changes or modifications will mark no material departure from the salient features of the invention as expressed in the appendant claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A crown for a watertight watch of the type having, an undivided winding-shaft surrounded by a tube; said crown being provided with an inner collar of packing material and a resilient plate above said packing collar which collar surrounds the Outer end of said winding-shaft and said tube, and a coupling part rigidly secured to the outer end of the winding-shaft and suitably shaped to overlap said packing collar and nutatably resting against said resilient plate pressed by said resilient plate against said packing collar.

2. A crown for a watertight watch of the type having an undivided winding-shaft surrounded by a tube; said crown being provided with an inner collar of packing ma terial and a rubber plate above said packing collar which collar surrounds the outer end of said winding-shaft and tube, and a coupling part rigidly secured to the outer end of the winding-shaft and suitably shaped to overlap said packing collar and nutatably resting against said rubber plate pressed by said rubber plate against said pack-ingy collar.

3. A crown for a watertight watch as per claim 1, in which said spring is of the plate-spring type having its marginal portions secured to the wall of said crown above said coupling part; and in which said coupling part is formed with an upwardly projecting rounded portion resting in point-like fashion against said plate-spring.

4. A crown for a watertight watch as per claim l, in which said coupling part is provided with a laterally projecting flange overlapping said packing collar and pressed by said resilient plate against said packing collar.

5. A crown for a watertight watch as per claim 1, including a metal ring suitably arranged to secure said collar of packing material within said crown.

6. A crown for a watertight watch as per claim 1, in which said coupling part is provided with a laterally projecting circular flange overlapping said packing collar and pressing said packing collar through the pressure exerted by said resilient plate against said tube.

7. A crown for a watertight watch-case having an elastically supported ring and watch-work therein and comprising a tube provided on said watch-case, an undivided winding shaft mounted unelastically in said watch-case and extending with play through said tube to the outside of said watch-case; said crown mounted on said watchcase over said tube, water-tight packing means between said crown and said watch-case, spring means inside said crown, and a coupling member rigidly attached to the end of said winding shaft inside said crown, said coupling member bearing nutatably against said spring means inside said crown so as to permit said winding shaft to follow freely the displacements of said elastically supported supporting ring and watch-work relative to said watch-case.

References Cited in the file of this patent FOREIGN PATENTS 434,651 Great Britain Sept. 5, 1935 264,359 Switzerland Jan. 3, 1950 273,735 Switzerland June l, 1951 1,029,191 France Mar. 4, 1953