US2700868A

US2700868A - Self-winding watch overwind preventer

Info

Publication number: US2700868A
Application number: US376409A
Authority: US
Inventors: Feigel Anton
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-05-23
Filing date: 1953-08-25
Publication date: 1955-02-01
Anticipated expiration: 1972-02-01
Also published as: CH298950A

Description

Feb. 1, 1955 FElGEL 2,700,868

SELF-WINDING WATCH OVERWIND PREVENTER Filed Aug. 25, 1953 IN VENT 0R.

Anion United States Patent SELF-WINDING WATCH OVERWIND PREVENTER Anton Feigel, Bronx, N. Y. Application August 25, 1953, Serial No. 376,409

7 Claims. (Cl. 58-83) In the construction of self-winding watches, an upper limit of the tension of the mainspring must be taken into account, and a device must be provided which prevents such limit from being exceeded.

The most simple device for this purpose, Which is most frequently used, comprises a loose piece of thicker mainspring coiled inside the barrel. The outer end of the mainspring is riveted to said piece which engages the inner wall of the barrel frictionally. A disadvantage of such known device is that the friction only ensures an approximate regulation or adjustment of the mainspring tension, which spring generally functions near its maximum tension. Furthermore, the spring is liable to get uncoiled in abrupt steps. Finally, the manufacture of 1sjuch lwatches necessitates the construction of a special arre.

Other known devices for regulating the tension of the mainspring comprise a relatively large number of intermediate movable elements, which renders them expensive. Moreover, their function does not offer sufficient accuracy.

Objects of my present invention are to eliminate the disadvantages of these known devices, to use a minimum of parts and elements, and to provide accuracy in the function of the device for regulating the mainspring tension.

Other objects and structural details of the invention will be apparent from the following description when read in conjunction with the accompanying drawing forming part of this specification, wherein the single figure is a top plan view of the winding mechanism of a self-winding watch according to the invention.

In said figures only those parts are shown which are necessary for a complete understanding of the invention.

In the upper face of the rockable weight 1, which is pivoted on the axle 2 situated in the center of the watch movement, a recess 3 is provided. The bridge of weight 1 is partly shown at 4. On a pin 5 fixed to weight 1 and situated in recess 3, is pivoted a pawl 6 of which the tip 7 coacts with the teeth of the winding pinion 8 which is pivoted on axle 2 of weight 1. A spring lever 9 is pivoted in recess 3 on a pin 10 fixed to weight 1. The movement of lever 9 to the right in the drawing is limited by a stop stud 11 fixed to weight 1.

A screw having an eccentric head 12 is mounted in a threaded bore of weight 1 to coact with a face 13 of the lower portion 14 of lever 9 and permits to regulate the latters tension.

The stud 11 is arranged on the weight 1 in such a position relative to the pawl 6 and the finger 15 of lever 9 is of such a curved shape, that pawl 6 just abuts against the extremity of finger 15 when it is in engagement with pinion 8 as shown in the drawing.

Spring 16 which at 17 is secured to pawl 6 by means of a pin 18, abuts against the wall of recess 3 at 19 and tends to move pawl 6 counterclockwise.

A cover 20, only partly shown, is secured to weight 1 by two

screws

21 and 22 and holds pawl 6 and the springs 9 and 16 in place in recess 3. Pinion 8 is connected to the barrel arbor and ensures the winding of the mainspring by gearwheels (not shown).

Let it be assumed that winding takes place when weight 1 rocks in the direction of arrow 23. During such movement, the tip 7 of pawl 6 engages pinion 8 and moves same counterclockwise, since the spring lever 9 normally prevents pawl 6 from turning counterclockwise on pin 5.

When weight 1 rocks in a direction opposite to arrow 23, while pinion 8 by means not shown is held stationary with the barrel arbor, pawl 6 swings clockwise on its pin 5 and its tip 7 passes simply on the crest of the teeth of pinion 8. During this movement, the leaf spring 16 urges pawl 6 in counterclockwise direction for keeping same in engagement with teeth of the pinion 8. Pawl 6 returns into its engaging position shown in the drawing, as soon as the weight 1 stops its clockwise rotation and starts to rotate in counterclockwise direction.

After each winding oscillation, the tension of the mainspring is increased, and the resistance which pinion 8 offers to the winding by pawl 6 increases accordingly.

Assuming now that the tension of the mainspring has attained its upper limit which should not be exceeded for the good function of the watch. In order to eliminate any further winding, which would increase the tension of the mainspring beyond such limit, it suflices to so regulate the force of spring lever 9 that, in its effect on pawl 6, it is less than the resistance of pinion 8. In such case, pawl 6 swings counterclockwise, and its tip 7 passes on the crest of the teeth of pinion 8 without I positively engaging the latter.

The eccentric screw 12 allows of accurately and quickly regulating the tension of spring lever 9, corresponding to the upper limit of tension of the mainspring, thus ensuring a greater security of operation than in the devices known so far.

While I have described and illustrated one embodiment of my invention, I do not wish to limit the scope of this invention unnecessarily, but reserve the right to make such modifications and rearrangements of the several parts as may come within the purview of the accompanying claims.

I claim:

1. In a self-winding watch of the type involving a rockable weight pivoted on an axle pin situated in the center of the watch movement, the improvement comprising a pawl pivoted to said weight, a pinion disposed coaxially with said weight in pivotal relation and adapted to wind the mainspring of the watch movement, a spring lever pivoted to said weight to engage said pawl, and a leaf spring secured to one end of said pawl and abutting against said weight, the whole in such arrangement that said pawl engages said pinion under the action of said spring lever and against the action of said leaf spring, and the spring lever permits said pawl to disengage itself from said pinion when the tension of said mainspring exceeds a certain upper limit.

2. A self-Winding watch as set out in claim 1, in which the spring lever holds the pawl in its engaging position through pressure action.

3. A self-winding watch as set out in claim 1, in which the spring lever yields to the pressure of the pawl when the tension of the mainspring reaches its upper limit.

4. A self-winding watch as set out in claim 1, in which a screw having an eccentric head and mounted in a threaded bore of the rockable weight coacts with a face of the spring lever to permit to regulate the tension of the spring lever.

5. A self-winding watch as set out in claim 1, in which a stop stud fixed to the rockable weight limits the swing of the spring lever.

6. A self-winding watch as set out in claim 1, in which the pawl and spring lever and leaf spring are disposed in a recess in the top face of the rockable weight.

7. A self-winding watch as set out in claim 6, in which a cover plate secured to the rockable weight by screws covers the pawl and spring lever and leaf spring and holds them in place for their respective functions.

References Cited in the file of this patent UNITED STATES PATENTS 1,853,637 Reiner Apr. 12, 1932 1,973,898 Henry Sept. 18, 1934 2,179,855 Latimer Nov. 14, 1939