US2921476A

US2921476A - Timepiece movement with a jumping second-beating hand

Info

Publication number: US2921476A
Application number: US728997A
Authority: US
Inventors: Vogt Paul
Original assignee: DERBY S A
Current assignee: DERBY S A
Priority date: 1957-06-29
Filing date: 1958-04-16
Publication date: 1960-01-19
Anticipated expiration: 1977-01-19

Description

Jan. 19, 1960 P. voe'r 2,921,476

TIMEPIECE MOVEMENT WITH A JUMPING SECOND-BEATING HAND Filed April 15, 1958 1718 (Z0 Z2 Z4 8 v 1113 181115 IN VEN TOR.

Paul vogr mWM Ma a- United States Patent TIMEPIECE MOVEMENT WITH A JUMPING SECOND-BEATING HAND Paul Vogt, Les Hauts-Geneveys, Switzerland, assignor to Derby S.A., La Chaux-de-Fonds, Switzerland Application April 16, 1958, Serial No. 728,997 Claims priority, application Switzerland June 29, 1957 9 Claims. (Cl. 74-84) The present invention relates to a timepiece movement with a jumping second-beating hand.

There are already known timepiece movements with a jumping second-beating hand, i.e. in which the second hand, instead of making for instance four or five jumps per second, is advanced one division at a time by an instantaneous mechanism. The known devices, however, have many drawbacks, in particular they are not reliable in operation and are very expensive.

The present invention aims to overcome the said drawbacks. It relates to a timepiece movement of the type referred to, which includes a wheel rigidly fixed to the spindle of the fourth wheel and forming the driving wheel of the second-beating mechanism, and a rocking bar subjected to the action of a spring and carrying near its free end a pinion and a pallet, the said pinion simultaneously meshing with the said driving wheel and with a wheel loosely mounted in the frame of the timepiece movement and forming the driven wheel of the secondbeating mechanism, the said loose wheel being non-coaxial with the said driving wheel and carrying a second hand, the said pallet being adapted to temporarily engage the said driven wheel, whereby on operation of the timepiece movement the pinion driven by the driving wheel rolls on the driven wheel while the said driven wheel is immobilized by the said pallet and moves the said rocking bar against the action of its spring until the pallet comes out of engagement from the driven wheel, the spring then acting for pushing back the rocking bar into its initial position, so that the pinion now rolls on the driving wheel which is temporarily unmoved and imparts to the said driven wheel a sudden rotation of one tooth at every second.

One embodiment of the invention will now be further described by way of example with reference to the accompanying drawing, in which:

Figure 1 is a fragmentary plan view of a timepiece movement constructed in accordance with the invention, seen from the side of the bridges of the movement.

Figure 2 is a sectional view taken along the line IIII of Figure 1, showing in addition a portion of the works of the movement.

Referring to the drawing there is shown a timepiece movement in accordance with the invention. In this construction the second hand is advanced one division, i.e. six degrees on the dial, at a time by an instantaneous mechanism.

The timepiece movement partially illustrated comprises a normal train of gears, consisting of the center wheel 1 with its pinion 2, of the third wheel 3 with its pinion 4, and of the fourth wheel 5 with its pinion 6, the part 5, 6 being placed out of the center of the movement. The spring barrel, the escapement and the balance are not illustrated. The above-mentioned movable parts are pivoted as usually in the pillar plate 7 and in the train wheel bridge or support 8.

Between the pillar plate 7 and a cock 9 secured to the train wheel bridge or support 8 is pivoted a spindle 10 2,921,476 Patented Jan. 19, 1960 rigidly fixed to a rocking bar or carrier member 11. A wire spring 12 bearing against the wall of a recess 13 of the train wheel bridge 8 and held on this bridge 8 by means of a screw 14 acts on the rocking bar or carrier member 11 and tends to rotate it in the clockwise direction in Figure 1. Near its free end the rocking bar 11 carries a pinion 15 and a pallet or detent 16 preferably made of a jewel such as ruby. The pinion 15 is loosely mounted on a pin 17 held by a drive fit in the rocking bar 11 and is maintained in axial direction by a collet 18. The pinion 15 is in mesh, on the one hand, with a wheel 19 rigidly attached to an extension of the spindle of the fourth wheel 5 and positioned outwardly of the train wheel bridge 8, and, on the other hand, with a center second wheel 20. The wheels or

gears

19 and 20 are the driving wheel and the driven Wheel of the secondbeating mechanism, respectively. The Wheel 20 is rigidly attached to a spindle 21 extending through the hollow shaft of the center pinion 2 and carrying at its free end a second hand 27. The spindle 21 is pivoted, on the one hand, in a cock 22 fixed to an extension 23 of the train wheel bridge 8 and, on the other hand, within the hollow shaft of the pinion 2, the spindle 21 being held in axial direction by means of a collar 24-.

On the shaft of the center pinion 2 is frictionally mounted in the conventional manner the cannon pinion 25 which is operatively connected by a well known gearing with the hour Wheel 26.

The pallet 16 has the same shape as a conventional lever pallet and is adapted to temporarily engage the teeth of the wheel 20, as explained later on.

The mechanism as shown and described operates as follows:

When the timepiece movement is running, the fourth wheel 5 and therefore the Wheel 19 are rotated and make little jumps, for instance at every fifth of a second. At the beginning of a cycle of one second, the rocking bar 11 has such a position that the pallet 16 engages the teeth of the wheel 20 and immobilizes that wheel. Due to the rotation of the wheel 19 in the counterclockwise direction in Figure 1, the pinion 15 is driven in the clockwise direction, but since the Wheel 20 is immobilized, the pinion 15 must roll on the wheel 20, its spindle 17 moving to the left in Figure l and therefore displacing the rocking bar 11 against the action of the spring 12. At every fifth of a second, the rocking bar 11 is displaced by one step in the counter-clockwise direction, so that the pallet 16 gradually comes out of engagement from the wheel 20. The size and the shape of the pallet 16 are designed in such a manner that on the fifth jump of the wheel 19, the pallet 16 gets clear of the teeth of the wheel 20 and allows the spring 12 to act for pushing back the rocking bar 11 into its initial position. During this sudden motion in the clockwise direction of the rocking bar 11, the wheel 19 remains unmoved and the pinion 15 can roll on it, whereby the pinion 15 is rotated in the clockwise direction of Figure 1 and drives the center second wheel 20 carrying the second hand 27. As soon as the rocking bar 11 has started its return motion in the clockwise direction, the pallet 16 again engages the teeth of the wheel 20, thereby again immobilizing the wheel 20 during the beginning of the next cycle.

Since the pinion 15 is permanently in mesh with both

wheels

19 and 20, it is impossible that the second-beating hand 27 be shifted by a time. greater than one second with respect to the

wheels

19 and 5.

The second-beating mechanism as shown and described is absolutely reliable in operation and its cost is very low. It consists of a small number of parts and can be mounted without difiiculty on an existing timepiece movement. The consumption of energy is small, because there is little friction and no jumper is required.

While I have described an illustrated one embodiment of my invention, I 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.

I claim: t

-1. A device for converting continuous rotary movement to step-by-step rotary movement comprising, in combination, a support; a driving wheel rotatably mounted on said support and adapted to rotate continuously; a driven wheel rotatably mounted on said support; a carrier member mounted on said support for reciprocating movement between two positions; motion transmitting wheel means rotatably mounted on said carrier member for simultaneous respective driving and driven engagement with said wheels during said reciprocating movement of said carrier member; detent means mounted on said carrier member for engagement with said driven wheel when said carrier member is in one of said positions thereof so as to impede rotation of said driven wheel, and for releasing said driven wheel when said carrier member is in the other position thereof; and resilient means urging said carried member to move toward said one position thereof.

2. A device for converting continuous rotary movement to step-by-step rotary movement comprising, in combination, a support; a first wheel rotatably mounted on said support and adapted to rotate continuously; a second Wheel mounted on said support for step by step rotation; a carrier member mounted on said support for reciprocating movement between two positions; motion transmitting wheel means rotatably mounted on said carrier member for simultaneous engagement withsaid wheels during said reciprocating movement of said carrier member; detent means mounted on said carrier member for engagement with said second wheel when said carrier member is in one of said positions thereof so as to impede rotation of said second wheel, and for releasing said second wheel when said carrier member is in the other position thereof; and resilient means urging said carrier member to move toward said one position thereof.

3. A device for converting continuous rotary movement to step-by-step rotary movement comprising, in combination, a support; a driving wheel rotatably mounted on said support, said wheel having an annular driving face and being adapted to rotate continuously at a predetermined speed of said driving face; a driven wheel rotatably mounted on said support; a carrier member mounted on said support for reciprocating movement between two positions; motion transmitting wheel means rotatably mounted on said carrier member for simultaneous respective driving and driven engagement with said driving face of said driving wheel and with said driven wheel during said movement of said carrier member; detent means mounted on said carrier member for engagement with said driven wheel when said carrier member is in one of said positions thereof so as to impede rotation of said driven wheel, and for releasing said driven wheel when said carrier member is in theother position thereof; and resilient means urging said carrier member to move toward said one position thereof at a speed greater than said predetermined speed.

4. A device for converting continuous rotary movement to step-by-step rotary movement comprising, in combination, a support; a driving gear rotatably mounted on said support and adapted to rotate continuously; a driven gear rotatably mounted on said support; a carrier member mounted on said support for reciprocating movement between two positions; motion transmitting gear means rotatably mounted on said carrier member for simultaneously respective driving'and driv engagement with said gears during said reciprocating movement-of said carrier member; detent means mounted on said carrier member for engagement with said driven gear when said carrier member is in one of said positions thereof so as to impede rotation of said driven gear, and for releasing said driven gear when said carrier member is in the other position thereof; and resilient means urging said carrier member to move toward said one position thereof. t

5. A device for converting continuous rotary movement to step-by-step rotary movement comprising, in combination, a support; a driving wheel rotatably mounted on said support and adapted to rotate continuously; a driven wheel rotatably mounted on said support; a carrier member mounted on said support for reciprocating movement between two positions; motion transmitting wheel means rotatably mounted on said carrier member for simultaneous respective driving and driven engagement with said wheels during said reciprocating movement of said carrier member; detent means mounted on said carrier member for engagement with said driven wheel when said carrier member is in one of said positions thereof so as to impede rotation of said driven wheel, and for releasing said driven wheel when said carrier member is in the otherposition thereof; and spring means urging said carrier member to move toward said one position thereof.

6. A device for converting continuous rotary movement to step-by-step rotary movement comprising, in combination, a support; a driving wheel rotatably mounted on said support and adapted to rotate continuously; a driven wheel rotatably mounted on said support; a carrier member pivotally mounted on said support for reciprocating movement between two positions; motion transmitting Wheel means rotatably mounted on said carrier member for simultaneous respective driving and driven engagement with said wheels during said reciprocating movement of said carrier member; detent means mounted on said carrier member for engagement with said driven wheel when said carrier member is in one of said posit-ions thereof so as to impede rotation of said driven wheel, and for releasing said driven wheel when said carrier member is in the other position thereof; and resilient means urging said carrier member to move toward said one position thereof.

7. A mechanical movement in a timepiece for converting continuous rotary movement to step-by-step rotary movement comprising a support; a rotary gear wheel mounted on said support; a toothed wheel rotatably mounted on said support spacedly adjacent said rotary gear wheel; a rocking bar mounted on said support for reciprocating rocking movement between two positions; pinion means mounted on said rocking bar and simultaneously meshing with said gear wheel and said toothed wheel; a spring permanently urging said rocking bar toward one of said positions thereof; pallet means on said rocking bar engaging said toothed wheel when said rocking bar is in said one position thereof so as to impede rotation of said toothed wheel, and releasing said toothed wheel when said rocking bar is in the other position thereof, whereby said pinion means when driven by said gear wheel in one direction rolls on said toothed wheel while movement of the latter is impeded by said pallet means so as to move said rocking bar against the restraint of said spring until the pallet means release said toothed wheel, the spring then acting for returning the rocking bar to its first position so that the pinion means rolls on the gear wheel and imparts to the toothed wheel a sudden rotation.

8. A mechanical movement as set forth in claim 7, said pallet means being made of a jewel.

9. A mechanical movement in a timepiece for converting continuous rotary movement of the fourth wheel of said timepiece to step-by-step rotary movement comprising a wheel bridge; a rotary gear wheel mounted on said wheel bridge and connected to said fourth wheel for joint, movement therewith; a toothed wheel rotatably mounted on said wheel bridge ,spacedly adjacent said wheel when said rocking bar is in the other position thereof, whereby said pinion means when driven by said gear wheel in one direction rolls on said toothed wheel while movement of the latter is impeded by said pallet means so as to move said rocking bar against the restraint of said spring until the pallet means release said toothed wheel, the spring then acting for returning the rocking bar to its first position so that the pinion means rolls on the gear wheel and imparts to the toothed wheel a sudden rotation.

UNITED STATES PATENTS Kaiser Ian. 12, 1886 Church Apr. 6, 1886 Olander Nov. 17, 1931 Robert-Charrue Jan. 1, 1952 Robert-Charme Apr. 8, 1952 Arni June 17, 1958 Hautau Nov. 4, 1958 FOREIGN PATENTS Switzerland Feb. 10, 1904 Great Britain Sept. 21, 1917 Switzerland Oct. 1, 1953