US2968143A

US2968143A - Quick hand shift means

Info

Publication number: US2968143A
Application number: US714591A
Authority: US
Inventors: Meyer Friedrich
Original assignee: Ebauches SA
Current assignee: Ebauches SA
Priority date: 1957-02-25
Filing date: 1958-02-11
Publication date: 1961-01-17
Anticipated expiration: 1978-01-17

Description

Jan. 17, 1961 F. MEYER QUICK HAND SHIFT MEANS Filed Feb. 11, 1958 IN VENTOR Friedrich Hagar BY i 'fi E United States Patent QUICK HAND srnrr MEANS Friedrich Meyer, Grenchen, Switzerland, assignor to Ebauches S.A., Neuchatel, Switzerland Filed Feb. 11, 1958, Ser. No. 714,591

Claims priority, application Germany Feb. 25, 1957 4 Claims. (Cl. 58-425) The present invention relates to a timepiece, and more particularly to a device for suddenly advancing an indicating member, e.g. an hour indicating member, in a timepiece movement, with a member subjected to the action of a spring and advancing once per unit of time a star wheel or the like, the said member being driven by means of a lag-coupling means. Such devices are preferably used when, instead of an hour hand, a rotary disk carrying the hour numerals is used, the said disk being suddenly actuated once in an hour, in order to suddenly bring the corresponding hour numeral in register with a window provided in a cover plate or dial.

In the known devices of this type, the member which advances the star wheel is an eccentric on which the spring acts during its whole rotation. When the spring leaves the point of the eccentric, the spring suddenly pushes forward the eccentric, to the extent allowed by the lag-coupling means, so that a pin of the eccentric acts upon a tooth of the star wheel cooperating with a jumper and thus rotates the star wheel suddenly by one tooth, i.e. by an interval corresponding to one hour. Since the eccentric acts upon the star wheel by means of a pin, the eccentric must pass below the star wheel, which involves an increase of the height of the mechanism. Since the relatively strong spring which advances the eccentric permanently bears against the eccentric, it also permanently exerts a frictional force on the latter. The driving wheel, actuated by the cannon pinion of the timepiece movement, driving the eccentric through the intermediary of the lag-coupling means, rotates by one revolution in an hour, so that the eccentric advances the star wheel only once by one tooth at each revolution.

These and other drawbacks can be overcome according to the invention by the fact that the said member is not constructed as an eccentric, but as a lever and that the spring acting upon the said lever has itself a control surface for bending the spring by means of the said lever and, adjacent to said control surface, an impulse surface for imparting to the lever a sudden motion. The lever-shaped member can, therefore, without the intermediary of a pin, act upon the star wheel and thus be situated in the same plane as the star wheel, which results in a smaller height of the mechanism. A twoarmed lever may be chosen and the driving wheel may be rotated at half a revolution per hour, so that for each revolution of the lever, the star wheel is advanced twiEeT When the lever has left the impulse surface of the spring, it remains out of contact from the said spring, that is to say the spring can no longer exert any friction, until it reaches again the control surface of the spring, so that a substantial reduction of the friction losses occurs.

The accompanying drawing illustrates, by way of example, one embodiment of the invention, at an enlarged scale.

Fig. 1 is a top plan view of the said embodiment.

Fig. 2 is a cross-sectional view taken along the line 11-11 in Fig. 1.

2,968,143 Patented Jan. 17, 1961 The wheel 1 is rigidly fixed to the cannon 2 of the cannon pinion 23 and meshes with a driving wheel 4 rotatably mounted on a cap screw 3. The wheel 4 has a number of teeth double of that of the wheel 1. While the wheel 1 rotates at one revolution per hour, the wheel 4, therefore, makes half a revolution during the same period. On the cannon 2 is freely mounted a star wheel 5 having twelve teeth, cooperating with a jumper 6. The star wheel 5 is rigidly fixed to a disk 7 carrying the numerals of the hours. Above the disk 7 and below the minute hand 8 lies the cover plate or dial 9 provided with a window 11) through which, in a known manner, the hour numerals of the disk 7 may successively appear. A two-armed lever 11 is rotatably mounted on the cap screw 3, so that it can rotate with respect to the Wheel 4 to the extent allowed by a lag-coupling means. The said lag-coupling means consists of the round hole 12 of the wheel 4 and of the pin 13 carried by the lever 11, the pin 13 engaging the hole 12. The hole of the lag-coupling means might also be provided in the lever 11 and the pin be carried by the wheel 4. The lever 11 lies in the plane of the star wheel 5, so that the

ends

18 and 20 of the lever 11 can act directly, that is to say without the intermediary of a pin, upon the teeth of the star wheel 5. In the plane of the lever 11 is arranged a load spring 15 for the lever 11, the spring 15 being secured on the pillar plate 14 or on another stationary part of the movement. The spring 15 has a curved control surface 16 and, adjacent thereto, a curved impulse surface 17. Both

surfaces

16 and 17, or one of them, might be replaced by plane surfaces. The control surface 16 serves for bending or tightening the spring 15 by means of the lever 11, and the impulse surface 17 serves for throwing or impelling the lever 11 forward with respect to the wheel 4 by means of the spring 15 bent by the surface 16, to the extent allowed by the lagcoupling means 12, 13.

In the position of the parts illustrated in Fig. 1, the driving wheel 4 which rotates in the counter-clockwise direction, has brought the lever end 18, by means of the lag-coupling means 12, 13, against the tooth 19 of the star wheel 5, whereas the lever end 21 lies at the end of the control surface 16 after having bent the spring 15 by engaging the said control surface. Now, if the driving wheel 4 further rotates in the counter-clockwise direction from the illustrated position, the lever end 20 suddenly leaves as at 22 the control surface 16, after expiration of an entire hour, and during relaxing of the spring 15, the impulse surface 17 suddenly pushes forward the lever 11, until the pin 13 strikes against the right side of the hole 12 and brings the lever 11 to a standstill. During this sudden advance, the lever end 18 turns by one tooth the star wheel 5 against the action of the jumper 6 and, therefore, the disk 7 up to the next hour numeral, in the clockwise direction, whereafter the jumper 6 maintains the wheel 5 in a known manner in this position. If the lever 11, owing to the shock of the pin 13 against the right side of the hole 12, should rebound backwards and thus tend to rotate the star wheel backwards against the action of the jumper 6, this would be prevented by the impulse surface 17, until the lag-coupling means 12, 13 again operates. As soon as the left side of the hole 12, on further rotation of the wheel 4, again strikes against the pin 13, the lever 11 is again driven by the wheel 4 in the counter-clockwise direction. Until the lever end 18 starts engaging the control surface 16, the lever 11 is not loaded by the spring 15. When the lever end 18 has engaged the control surface 16 and has reached the position in which the lever end 211 is shown in the drawing, a short time afterwards, namely after expiration of a further hour, the lever end 18 is suddenly impelled by the impulse surface 1'7 and the lever end 20 suddenly pushes the next tooth 21 of the star wheel 5 in the clockwise direction. Then, when the lever end 20 has come back in the same manner as above described for the lever end 18, into the position of Fig. 1, the cycle starts again.

Under certain circumstances, the device in accordance with the invention may be used for jumping minutes.

If it is desired to set the disk '7 and the minute hand 8 backwards, i.e. to rotate the driving wheel 4 in the clockwise direction, this is possible without further ado, since, with the setting force available, not only the star wheel 5 can repel the jumper 6, but also the lever 11 is albe to repel the impulse surface 17 and, therefore, the spring 15.

While I have described and illustrated one embodiment of my invention, 1 do not wish to unnecessarily limit the scope thereof, but reserve the right to make such modifications and rearrangements of the several parts as may come within the purview of the accompanying claims.

What I claim is:

1. A device'for suddenly advancing an indicating member, particularly an hour indicating member, in a timepiece movement, with a member subjected to the action of a spring and advancing once per unit of time a star wheel, the said member being driven by means of a lagcoupling means, the said member being constructed as a lever and the spring acting upon the said lever having a control surface for bending the spring by means of the said lever and, adjacent to said control surface, an impulsesurface for imparting to the lever a sudden motion, at least one of the control and impulse surfaces being curved.

2. A device according to claim 1, in which the said lever has two arms, so that for each revolution thereof, it advances the star wheel twice.

3. A device according to claiml, in which the lever lies in the same plane as the star wheel, so that the ends of the lever act directly upon the star wheel.

4. in a device for suddenly advancing an indicating member, particularly an hour indicating member, in a timepiece movement, a rotatable star wheel rigidly connected with said indicating member, a spring, a lever subjected to the action of said spring and advancing said star wheel once per unit of time,"said lever being driven by means of a lag-coupling means, said spring having a control surface through which the spring is bent by the lever a'nd,'-adjac'ent to said control surface, an impulse s'urface through which the spring imparts a sudden mo- 'tion to the lever.

References Cited in the file of this patent FOREIGN PATENTS