United States Patent 3727398
Abstract:
A timepiece such as a timecounter or a chronograph comprising a column wheel, a control member permitting the column wheel to be driven step by step unidirectionally so that the successive operations of the control member produce successively starting, stopping and setting to zero of the hand of the counter or of the chronograph, and which comprises a second control member permitting the column wheel to be driven reversely one step, so that the operation of the second control member, when the counter or chronograph is stopped, effects its restarting.
Application Number:
05/256292
Publication Date:
04/17/1973
Assignee:
Valjoux S.A. (Les Bioux, Canton of Vaud, CH)
International Classes:
G04F7/04; G04F7/06; G04F7/00; (IPC1-7): G04F7/04
Field of Search:
58/74-79,22.9
Primary Examiner:
Miller Jr., George H.
Claims:
I claim
1. A timepiece such as a timecounter or chronograph comprising, a column wheel, a control member permitting the column wheel to be driven step by step unidirectionally so that the successive operations of the control member produce successively starting, stopping and setting to zero of the hand of the counter or of the chronograph, and a second control member permitting the column wheel to be driven reversely one step, so that the operation of the second control member, when the counter or chronograph is stopped effects its restarting, the column wheel being provided with a number of teeth which is a multiple of three, each third tooth having its rear face so conformed that the second control member, when it is operated, produces the reverse movement of one step of the column wheel, the other teeth of each group of three teeth presenting rear face so conformed that the control member bears thereon, when it is operated, without producing displacement of the column wheel.
2. A timepiece as claimed in claim 1, wherein two teeth of each group of three teeth of the column wheel are ratchet teeth and have their rear faces inclined and which extend to the base of the front face of the preceding tooth, with the third tooth having its front and rear face disposed substantially symmetrically with respect to the axis of the tooth.
3. A timepiece as claimed in claim 1, wherein the two control members comprise a pair of beaks integral with a lever having first and second pairs of bearing surfaces, a pushing member for acting on the first pair of bearing surfaces, the second pair of bearing surfaces being rounded, a spring for maintaining the lever under tension and for urging the second pair of bearing surfaces against the frame of the movement wherefore, as pressure is exerted on the center of one or the other of the second pair of rounded bearing surfaces that surface contitutes the center of rotation of the lever.
Description:
This timepiece is characterized by the fact that the ratchet toothing of the column wheel with which the first control member cooperates for driving it step by step comprises a number of teeth which is a multiple of three, each third tooth having its rear face conformed in such a way that the second control member, while acting on this rear face, produces the rearward movement of one step of the column wheel, while the two other teeth of each group of three teeth show a rear face conformed in such a way that the second control member bears thereon when it is operated, without producing any displacement of the column wheel.
The drawing shows, by way of example, one embodiment of the invention.
The sole FIGURE is a plan view of a part of a timecounter.
The timecounter represented comprises a column wheel constituted by a ratchet wheel 15 provided with four columns 15a. These columns control a lever 16 provided with a whip serving to stop and to drive the balance wheel of the movement of the counter and a hammer 17 acting on a heart piece 18 for resetting the hand of the counter to zero, which hand is not shown and is carried by a shaft 19.
A control lever 20, under tension of a return spring 21, bears by two arc-shaped surfaces 22 and 23 on the baseplate 24 of the movement. When a pressure is exerted at 25 on a first bent portion 20a of the lever 20, the center of the arc-shaped surface 22 serves as a center of rotation of the lever, a beak 20b of which then cooperates with the ratchet wheel of the column wheel for rotating it step by step in the direction of the arrow 26, to produce successively starting, stopping and return to zero of the hand of the counter.
The ratchet wheel 15 has twelve teeth, that is to say a multiple of three, and each third tooth, designated by 15b, has a rear face 27 which, rather than being inclined upwardly from the base of the front face of the preceding tooth, as are the rear faces 28 of the two other teeth 15c of each group of three teeth, is substantially symmetrical with the front face 29 with respect to the axis of the tooth.
The lever 20 includes a second beak 20c which, when pressure is exerted at 30 on a second bent portion 20d of the lever, rotating it around the center of its bearing surface 23, cooperates with the rear face of the teeth of the ratchet wheel 15. When it is one of the normal teeth 15c of the ratchet wheel which is opposite the beak 20c, when the counter is operating or when its setting to zero has been effected, the beak 20c slides on the rear inclined face 28 of the tooth 15c of the ratchet wheel 15 on which it bears without driving it. When, on the contrary, a tooth 15b of the ratchet wheel 15 is situated opposite the beak 20c of the lever 20, when the counter is stopped before it has been returned to zero, the beak 20c acts on the rear face 27 of the tooth 15b, to produce the rearward rotation of one step of the column wheel in a direction opposite to that of arrow 26, thus restarting the counter.