Self-winding Watch

Abstract

A winding system for a self-winding wrist watch having a driven ratchet wheel for winding a mainspring by driving the ratchet from an oscillatory pawl oscillated by an eccentric axle driven by an oscillating weight and without the use of a conventional bridge element.

Description

This invention relates generally to wrist watches and more particularly a winding system for self-winding wristwatches.

The conventional self-winding wristwatches have a bridge and other structure for effecting self-winding. This type of self-winding arrangement limits substantially the extent that wrist watches may be made thin in their thickness dimension.

It is an object of the present invention to provide an improved self-winding system for wrist watches.

Another object is to provide a winding system for self-winding of a wrist watch that allows making of thin wrist watches.

According to the invention a winding system for a self-winding wristwatch has a transmission wheel driven from a bearing pivotally mounting an oscillatable weight oscillating a pawl for driving a toothed wheel driving a ratchet in one direction only for winding.

Other features and advantages of the winding system in accordance with the present invention will be better understood as described in the following specification and appended claims, in conjunction with the following drawings in which:

FIG. 1, is a plan view of a known watch winding system;

FIG. 2, is a section view taken along section line 2--2 of FIG. 1;

FIG. 3, is a plan view of a wrist watch winding system according to the invention; and

FIG. 4, is a section view taken along section line 4--4 of FIG. 3.

According to the drawings conventional wrist watch winding systems have a bearing comprising an inner ring 1, 2 and balls 3 within the inner ring 4 and an outer ring pivotally mounting an oscillatable weight 5. A two-arm pawl 8 is actuated, as later explained, to drive a toothed wheel 11 having a saw-toothed periphery and integral with a pinion 12 pivotal on a plate 10 and meshing with a gear 13.

A bridge 18 is required in the conventional winding system for self winding. An eccentric pin 19 fixed to the inner ring 2 is imparted oscillatory motion for actuating the pawl 8 to drive the toothed wheel 11 rotationally for winding a mainspring, not shown. A threaded screw fixes the eccentric weight 5 to the bearing.

This type of winding system has a disadvantage in that the eccentric pin 19 fits into an opening in the pawl and tends to wear as it oscillates the pawl. The winding system according to the invention illustrated in FIGS. 3 and 4 eliminates this disadvantage and eliminates the need of the bridge 18 so that the winding system occupies less space in the thickness direction of a watch and a wristwatch provided with the invention can be made thinner than a wrist watch provided with a winding system such as that described.

In FIGS. 3 and 4 a winding system embodying the invention is illustrated. This system has a bearing comprising inner ring means 1', 2' with bearing balls 3' held between the ring means 1', 2' and an outer ring or race 4' pivotally mounting an oscillatable weight 5' fixed thereto. A transmission wheel 6 has peripheral teeth meshing with peripheral teeth on the bearing race or outer ring 4'. An eccentric axle 7 is constructed integral with the transmission wheel 6 and a threaded screw 9 fixes the bearing on a plate 10 as illustrated.

A two-arm pawl lever 8' engaged with the eccentric axle 7 has pawls 8a, 8b for driving a toothed wheel 11' integral with a pinion 12' driving another toothed or ratchet wheel 13' for winding a mainspring, not shown. The toothed wheel and ratchet wheel are likewise mounted on the plate 10 without need of a bridge. The transmission wheel 6 and its eccentric axle 7 are fixed to the plate 10 by a sleeve 14 and screw 15. The toothed wheel 11' is secured to the plate 10 by a sleeve 16 and a screw 17 as shown.

When the oscillating weight 5 revolves, the outer ring 4 begins to rotate and then the transmission wheel 6 meshing with the outer ring. Thus the eccentric axle 7, in one piece with said wheel 6, lets the pawl lever 8 move with the axle 7 acting as its pivot. Rotation on this pivot avoids wear and tear on the pivot and the pawl lever. The pawls 8a and 8b are thus moved with an oscillatory motion. The saw toothed wheel 11 is turned only in a clockwise direction. Therefore the pinion 12, and the rachet wheel 13 are revolved, so the mainspring is wound up.

As above mentioned, according to the present invention, there is no need to set a bridge for self winding. It is thus possible to make a thinner watch and the construction of the winding system is strong against abrasions in long use.

Claims

I claim:

1. For use in self-winding wristwatch a self-winding system comprising, a wheel saw-toothed peripherally driven in only one direction, means having a pair of integral pawls oscillatable about a pivoted axis for driving said saw-toothed wheel in one direction only, eccentric pivot means providing said pivotal axis, a transmission wheel integral with said eccentric pivot means for rotating said eccentric pivot means, said eccentric pivot means disposed eccentric to said transmission wheel, said means having the pair of integral pawls comprising means integral with said pawls circumferentially of said eccentric pivot means driven thereby, said transmission wheel having peripheral teeth, an oscillating weight, ball bearing means providing a pivot for said weight having peripheral teeth meshing with said transmission wheel, a pinion driven in conjunction with said wheel driven in one direction, a ratchet wheel having peripheral teeth meshing with said pinion for winding a mainspring, a plate mounting said pivot means, said wheel driven in one direction, said ball bearing means and said ratchet wheel, and said transmission wheel being disposed between said oscillating weight and said plate.

2. For use in a self-winding wristwatch a self-winding system according to claim 1, in which said ball bearing means comprises an outer ring having said peripheral teeth, and said oscillating weight being disposed fixed to said outer ring.