US3122879A

US3122879A - Motion converter for electrically driven rotary oscillators

Info

Publication number: US3122879A
Application number: US59303A
Authority: US
Inventors: Trick Kuno; Schulte Theodor; Herr Fritz; Wolber Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-10-01
Filing date: 1960-09-29
Publication date: 1964-03-03
Anticipated expiration: 1981-03-03

Description

March 3, 1964 K. TRICK ETAL 3,122,879

MOTION CONVERTER FOR ELECTRICALLY' DRIVEN ROTARY OSCILLATORS Filed Sept. 29, 1960 INVENTOM K. TPL'cA 7T6cLuZ BY Her/- 4 R. WoZZer A itzya.

United States Patent 3,122,879 MOTION CONVERTER FOR ELECTRICALLY DRIVEN ROTARY OSCILLATORS Kuno Trick, Tosstr. 41; Theodor Schulte, Tiersteinstr. 82;

and Fritz Herr, Kolpingstr. 18, all of Schramberg,

Germany; and Robert Wolber, Lauterbach, Holzle,

Germany Filed Sept. 29, 1960, Ser. No. 59,303 Claims priority, application Germany Oct. 1, 1959 5 Claims. (CI. 58-28) The invention relates to a driving mechanism for electrically-driven rotary oscillators, particularly for wrist watches, with a swing fork actuating a stepping wheel and whose swinging movement is limited by stops.

Such driving mechanisms are known for wrist watches in which at each oscillation the stepping wheel of the hand movement is moved on one tooth by a pin fixed on the movement regulator or an ellipse. In the case of such driving mechanisms it may happen that the movement regulator, due to a jolt, for example a sudden movement of the arm, is energized to carry out such strong oscillations that the stepping wheel is moved on several teeth at each oscillation. Moreover the hand movement is not constantly in engagement with the movement regulator. This, however, engages the stepping Wheel for a relatively short time during an oscillation. To secure the stepping wheel against turning in the intervals between the steps, a mechanically or magnetically actuated locking mechanism is generally provided which prevents at least back movement of the stepping wheel. The forces exerted by this locking mechanism on the stepping wheel can naturally only be so slight that, on the occurrence of relatively great forces for example when setting the hands, these locking forces of the ordinary mechanism are overcome and the stepping Wheel is advanced. The second hand is in this case moved in clockwise direction or in counter-clockwise direction with great jumps and exact setting of the hands is not possible.

The object of the invention is to produce a driving mechanism for electrically driven rotary oscillators, in which the fork is held in its extreme positions and in which the jumping or slipping of the stepping wheel is reliably prevented.

According to the invention, the fork is in operative connection with a holding member elastically acting on it and at least one of the cooperating parts is so shaped that for obtaining counter-directed forces in the two extreme positions of the fork, different parts of the members come into operative connection with each other. In a mechanism with a fork feeding the stepping wheel at each full oscillation, a safety cam is preferably provided in addition to the stepping or operating cam in such a manner that it is located in a tooth gap of the stepping wheel when the fork is in its extreme or end position and the stepping or operating cam has left a tooth gap of the stepping wheel.

An embodiment of the invention is hereinafter described by way of example with reference to the accompanying drawing, in which the single figure is a diagrammatic side view showing an arrangement in which the operating fork carries an operating cam and a safety cam.

The rotary oscillator is designated by 80 and carries a pin 82 engaging the limiting fork 81. The swinging movement: of the fork or pallet 81 is limited by stops {83 and 84.

Pins

86 and 87 are mounted on the arm of the fork 81 but do not both have to function to move on the stepping wheel at each half oscillation of the movement regulator 80, the movement of the stepping wheel being effected only by the pin 87 whereas the pin 86 only serves as run-through safety stop for the stepping wheel 88. The limiting fork has an aperture 89 by which the arm 85 thereof is divided into two parallel strips and 91 which cooperate with a permanent magnet 92. Thus the fork 81 made from magnetic material is held in its end positions by the stops 83 and 84.

The magnetic holding forces are however only strong enough that they can be overcome by the switching impulses of the rotary oscillator.

The drawing shows the fork or pallet 81 in its initial end position in which it bears against the stop 83 and is held thereto by the permanent magnet 92 acting on the strip 9t). In this end position the locking pin 86 is located in a tooth gap of the stepping wheel 88, whereas the operating pin 87 is outside the periphery of the stepping wheel. ()n the fork 31 being moved inwards the operating pin 87 is moved in the direction towards the stepping wheel and comes into contact with one of the teeth thereof with the result that the stepping wheel is turned so far that the magnetic forces become so strong in relation to the next following tooth that the stepping wheel moves on one tooth. During this movement of the stepping wheel, the safety pin 86 is not located in one of the tooth gaps so that the step movement is not impeded. On the other hand the operating pin 87 now stands in a tooth gap of the stepping Wheel (see broken line contours). One of the pins 86, S7 is always located in a tooth gap so that slipping or mounting the stepping wheel 88 in the event of any increased moments of rotation occurring, is prevented in any case.

However, under normal operating conditions the stepping wheel is held by the magnet 93 in the intervals between the stepping-on movements, so that the safety pin 86 does not as a rule come into contact with the ste ping wheel 83 at all.

It has been found that particularly good operation of the arrangement according to the invention is obtained if the flat wall face of the operating pin 87 is substantially tangential to its direction of movement, whereas the flat face of the safety pin 86 is approximately perpendicular thereto.

We claim:

1. Driving mechanism for an electrically driven rotary oscillator especially for wrist watches, comprising a stepping wheel rotatably mounted and having a plurality of teeth with tooth gaps between the teeth in the periphery of the wheel, a swing fork pivoted to oscillate between stop elements and pivoted intermediate its ends, an elastic holding means to hold the fork in its end positions against the stop elements, and a pair of spaced pins mounted on one end of the swing fork to cooperate with the teeth in the stepping wheel, one of the pins being an operating pin and the other a safety pin so that when the operating pin has moved the stepping wheel and is retracted out of contact with the teeth of the wheel the safety pin will be situated in a tooth gap free of contact with the stepping wlheel when said fork is in one of said end positions.

2. Controlling mechanism according to claim 1, in

which the pins each have a curved portion which is elliptic in contour and a flat portion.

3. Controlling mechanism according to claim 1, in which each pin has a fiat surface with such fiat surface of the operating pin being substantially tangential to the direction of movement of the pin and the fiat surface of the safety pin is substantially vertical as to the movement.

4. Controlling mechanism according to claim 1, in which at least one permanent magnet is provided secured in position in operative relation with the stepping wheel, and in which the teeth of the stepping wheel are composed of magnetizable material whereby the teeth of the wheel will form armatures for the magnet to retain the wheel in a position of rest when the operating pin is retracted out of contact with the teeth of the wheel.

5. Controlling mechanism according to claim 1, in

'4 which said holding means comprises a pair of spaced strips of magnetizaole material on said fork and a permanent magnet is securely mounted at right angles to the movement of the fork so that the strips will be influenced by the magnet in each end position of the oscillating fork.

References Cited in the file of this patent UNITED STATES PATENTS 10 2,865,163 Ensign et al Dec. 23, 1958 2,971,324 Beyner Feb. 14, 1961 FOREIGN PATENTS 647,217 France July 24, 1928 15 923,788 France Feb. 24, 1947

Claims

1. DRIVING MECHANISM FOR AN ELECTRICALLY DRIVEN ROTARY OSCILLATOR ESPECIALLY FOR WRIST WATCHES, COMPRISING A STEPPING WHEEL ROTATABLY MOUNTED AND HAVING A PLURALITY OF TEETH WITH TOOTH GAPS BETWEEN THE TEETH IN THE PERIPHERY OF THE WHEEL, A SWING FORK PIVOTED TO OSCILLATE BETWEEN STOP ELEMENTS AND PIVOTED INTERMEDIATE ITS ENDS, AND ELASTIC HOLDING MEANS TO HOLD THE FORK IN ITS END POSITIONS AGAINST THE STOP ELEMENTS, AND A PAIR OF SPACED PINS MOUNTED ON ONE END OF THE SWING FORK TO COOPERATE WITH THE TEETH IN THE STEPPING WHEEL, ONE OF THE PINS BEING AN OPERATING PIN AND THE OTHER A SAFETY PIN SO THAT WHEN THE OPERATING PIN HAS MOVED THE STEPPING WHEEL AND IS RETRACTED OUT OF CONTACT WITH THE TEETH OF THE WHEEL THE SAFETY PIN WILL BE SITUATED IN A TOOTH GAP FREE OF CONTACT WITH THE STEPPING WHEEL WHEN SAID FORK IS IN ONE OF SAID END POSITIONS.