CH688068B5 - Second indicator device for a timepiece. - Google Patents

Description

1

CH 688 068G A3

2

Description

Mechanical timepieces are known comprising an indicating device in which the indicating member periodically scans a graduated circle sector and then instantly returns to its initial position. One of the aims of these devices is to limit the movement of the indicating organs concerned, thus allowing the corresponding graduations not to extend over the entire periphery of the dials and finally to facilitate the reading of the indications of the indicating organs.

In these parts, the mechanism generating the movement of the indicator member consists of a pinion whose teeth have a solution of continuity, by a rake kinematically connected to the indicator member, and by a return spring of the rake.

Unfortunately, the mechanisms of this type which have been imagined have a significant defect, residing in the fact that the pinion and the rake do not reengage immediately after the return of the indicator member to its initial position.

Indeed, in these mechanisms, the rake is driven, after returning to its initial position, firstly by means of a finger and a stop, then only secondly, by the pinion.

In the corresponding time interval, the rake is subjected to various mechanical stresses, in particular to shocks, which generate an uncontrolled and disordered movement of the indicating member.

During this time, the indications of this organ are obviously not reliable.

The present invention relates to an indicator device of the type in question which does not have this defect. This device is defined by claim 1 of this patent.

The attached drawing shows schematically and by way of example, an embodiment of the object of the invention.

Fig. 1 is a plan view of the device at "zero second" time.

Fig. 2 is a view similar to FIG. 1 at time "sixty seconds".

Fig. 3, which corresponds to a superposition of FIGS. 1 and 2, illustrates the phase during which the seconds indicator body returns to its starting point.

The device shown consists of a mechanism comprising a pinion 10 driven at the rate of one revolution per minute in the direction of arrow F, a rake 11 cooperating with this pinion 10, a spiral spring 12, one end of which is anchored to a peg fixed 13 and the other attached to the base of the rake 11, and by seconds display means comprising a needle 15 angularly integral with the rake 11 and a graduation 16, divided into 60 seconds, extending over an arc of about 40 degrees, in front of which the needle 15 moves.

The pinion 10 has five teeth numbered from 1 to 5 and has a continuity solution corresponding to a tooth, the rake 11 also has five teeth, also numbered from 1 to 5, its tooth 1 being slightly longer than its other teeth.

The mechanism thus formed prints during each minute a sweeping movement with the needle 15, the amplitude of which corresponds to the circular arc of the graduation 16, the return of this needle 15 taking place instantaneously at the end of each minute. .

At time zero (needle 15 opposite the first line of the scale 16), the tooth 1 of the rake 11 bears under the action of the spring 12, partially pre-armed, against the tooth 1 of the pinion 10 (fig.

1).

From this time, the pinion 10 drives, at constant angular speed, clockwise, the rake 11 and the needle 15 opposite the scale 16, further winding the spring 12.

At the sixtieth second, the tooth 5 of the rake 11 escapes the tooth 5 of the pinion 10 and the spring 12 expands causing an instant retrograde movement of the rake 11 and the needle 15 (fig. 2).

This movement is stopped by tooth 1 of the pinion 10 against which tooth 1 of the rake 11 abuts (fig. 3).

The same cycle is repeated over the next minute. During each cycle, the rake 11 and the needle 15 are driven continuously, without dead time, exclusively by meshing the pinion 10 and the rake 11.

The invention is obviously not limited to the embodiment shown and described.

In particular, the graduation 16 could extend over any arc of a circle and the instantaneous re-engagement of the pinion 10 and the rake 11 when the needle 15 returns to its zero position can be obtained by other mechanisms than the mechanism. described.

The needle 15 could also be replaced by a graduated disc, the indications of which would appear in a window. Finally, the return to zero of the needle 15 could take place not in the retrograde direction, but in the direction of counting.

Claims (2)

Claims 1. Second indicator device for a timepiece in which the indicating member (15) scans, during each minute, a sector of a circle graduated from zero to sixty seconds, and then instantly returns to its initial position, the mechanism generating this movement comprising a minute pinion (10), the teeth of which have a solution of continuity, a rake (11) kinematically connected to the indicator member (15), and a return spring (12) of the rake (11), characterized by the fact that said mechanism is arranged so that the drive of the rake (11) from its angular position corresponding to the initial angular position of the indicator member (15) to its angular position corresponding to the maximum angular position of this member (15) is provided exclusively by meshing the pinion (10) and the rake (11). 2. Device according to claim 1, characterized 5 10 15 20 25 30 35 40 45 50 55 60 65 3 3 CH 688 068G A3 by the fact that, to ensure this continuous drive, without dead time, of the rake (11), the tooth of the pinion (10) immediately following the continuity solution, is longer than the others. 5 10 15 20 25 30 35 40 45 50 55 60 65 4