Patent Publication Number: US-4922474-A

Title: Timepiece and method for its realization

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a timepiece having at least one indicating member the driving of which is able to be interrupted, and the driving mechanism of which is uncoupled to this effect. 
     This invention relates also to a method for the realization of this timepiece. 
     This invention has for purpose to permit to transform easily a conventional timepiece, comprising only the usual time indicators (hours, minutes and, may be, seconds) into a timepiece having at least one indicating member the running of which can be interrupted and re-established at will, that is the case, especially, of the chronograph watches. 
     The various features of the invention will be apparent from the following description, drawings and claims, the scope of the invention not being limited to the drawings themselves as the drawings are only for the purpose of illustrating ways in which the principles of the invention can be applied. Other embodiments of the invention utilising the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a chronograph mechanism of a chronograph watch. 
     FIGS. 2 and 3 are similar views, to a smaller scale, of this mechanism represented in two other working positions. 
     FIG. 4 is a sectional view on the line IV--IV of FIG. 2, to a larger scale, and 
     FIG. 5 is a sectional view on the line V--V of FIG. 2, to the scale of FIG. 4. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present timepiece, the only elements of which are necessary to the understanding of the invention have been represented, comprises a conventional clockwork, the frame of which is designated by 1, this clockwork driving the conventional time indicators (hours, minutes and seconds), not represented. The gearing of this clockwork comprises a small-seconds shaft 2 (FIG. 4), making one revolution per minute, situated on the line 6-12 o&#39;clock of the watch, which extends beyond the frame of the clockwork, and the protruding end of which carries normally a small seconds-hand which has been eliminated. 
     The frame 1 of the conventional clockwork carries, mounted on its face which, normally, would be provided with the watch dial, the frame, comprising two base-plates 3 and 4, of an auxiliary mechanism, of chronograph, this frame being provided with a dial 5. The base-plate 3 of this auxiliary mechanism, situated under the dial 5, carries the bearing 6 of a shaft 7, coaxial to the shaft 2, carrying a seconds or chronograph-hand 8. The shaft 7 is supported, at its opposed end, by a flexible bridge 9 secured to a not represented element of the frame of the chronograph mechanism, which exerts on the shaft 7 an axial pressure urging a resetting heart 10 carried by this shaft against the bearing 6 and, hence, tending to create on the shaft 7 a friction preventing any play of the hand 8. 
     The shaft 7 carries, freely mounted thereon, a driving wheel 11 which is frictionally connected to the heart 10 by a cambered washer 12 interposed between this wheel 11 and the said heart. 
     The protruding end of the shaft 2 of the gearing of the conventional clockwork of the watch carries, in lieu of the conventional small seconds-hand, a wheel 13, of the same number of teeth that the wheel 11 with which it is coaxial. 
     The chronograph mechanism comprises a lever 14, articulated at 15, which carries a double sliding pinion 16-17 the two elements of which, which are rigidly connected to each other, are situated each on one of the faces of the said lever. These two pinions, having the same number of teeth, mesh, when the lever 14 occupies its coupling position, represented in FIGS. 2 and 4, with the two wheels 11 and 13, respectively, that renders them rigid with each other and thus ensures the driving of the chronograph hand 8. 
     It is to be noted that the two wheels 11 and 13 could have a different number of teeth as well as the two sliding pinions 16 and 17. 
     The lever 14 is submitted to the action of a return spring 18 which urges it into its coupling position. It is operated by a column-wheel 19 realized as a cam having six noses, rigid with a ratchet-wheel 20 having twelve teeth. This ratchet-wheel is operated by a pawl 21 articulated at 22 on a chronograph lever 23, which is itself articulated at 24, and is operated by means of a pusher 25. The pawl 21 is prolongated by a portion 21a which is resiliently deformable, bearing on the head of a jumper 26, articulated at 27, ensuring the stability of the several positions of the column-wheel. Thus, the spring 21 has a triple purpose: on the one hand, it returns the pawl 21, applying it against the ratchet-wheel 20, on the other hand it returns the jumper 26, applying it also against the ratchet-wheel 20, and then it returns the chronograph lever 23 into its rest position represented in the drawing. 
     The timepiece moreover comprises a minutes indicator (minutes counter) constituted by a hand 28 (FIG. 5) mounted on a shaft 29 rotating between the base-plates 3 and 4 of the frame of the chronograph mechanism and which is rigid with a resetting hammer 30. A cambered washer 31 is interposed between the heart 30 and the base-plate 3 so as to produce on the shaft 29 a friction preventing any play of the hand 28. The shaft 29 carries a wheel 32 freely mounted thereon and which is frictionally connected with the heart 30 by a cambered washer 33 interposed between the heart and the said wheel, that permits the resetting of the hand 28 being effected without wheel 32 is driven. This wheel is driven, through the intermediary of a gearing comprising two elements 34 and 35 and an intermediate wheel 36, by the wheel 11 which drives the chronograph hand 8 and which meshes with the intermediate wheel 36. 
     It results from this arrangement that, when the wheel 11 is driven, the pinions 16 and 17 being meshed with wheels 11 and 13, respectively, the hand 28 is also driven. 
     The resetting of the two hands 8 and 28 is effected by means of a resetting lever 37 articulated at 38 provided with two peens 37a and 37b constituting two hammers cooperating with the resetting hearts 10 and 30 respectively. The resetting lever 37 is submitted to the action of a return spring 39 which urges it to rotate in the counter clockwork direction for bringing the two hammers to cooperate with the two resetting hearts. The return of the resetting lever 37 into its rest position, in which its two peens 37a and 37b are distant from the hearts 10 and 30, respectively, is effected by means of the chronograph lever 23 which is provided, to this effect, with an extension 23a cooperating with an arm 37c of the lever 37. The latter is moreover provided with a beak 37d which gets caught, when the lever is brought into its rest position by the chronograph lever 23, to a retaining lever 40, articulated at 41, submitted to the action of a return spring 42, and which is operable by means of a resetting pusher 43. This lever is provided, at its end, with a notch 44 (FIG. 1) into which gets caught the beak 37d of the resetting lever 37. 
     This chronograph operates as follows: when the mechanism occupies its stopping position, the hands 8 and 28 being reset to zero and being held in this position by the two hammers 37a and 37b, respectively, that is the position represented in FIG. 1, a pressure exerted on the pusher 25 brings the column-wheel 19 into the position represented in FIG. 2 in which, under the action of its return spring 18, the lever 14 has rotated in the clockwork direction, bringing the double slide pinion 16-17 it carries to mesh with the two coaxial wheels 11 and 13, respectively, that produces the driving of the hands 8 and 28. 
     Simultaneously, the end portion 23a of the lever 23 acting on the arm 37c of the resetting lever 37 has made the latter to rotate in the clockwork direction, against the action of its return spring 39, releasing the two hearts 10 and 30. At the end of the stroke of the lever 37, its beak 37d has engaged the notch 44 of the lever 40, while lifting this lever slightly against the action of its return spring 42. Hence, in this position (FIG. 2), the hands 8 and 28 are driven and the hammers 37a and 37b are maintained distant from the resetting hearts. 
     It is to be noted that, if in this position of the mechanism a pressure is exerted on the resetting pusher 43, this wrong operation will have no effect since, then, a nose 40a of the retaining lever 40 abuts against an arm 14a of the lever 14, that prevents it from moving up to the releasing of the resetting lever 37. 
     The chronograph being in operation, a pressure exerted on the pusher 25 produces the displacement of one step of the column-wheel 19, that lifts the lever 14, thus disengaging the double sliding pinion 16-17 carried by this lever from the wheels 11 and 13, thus discoupling the chronograph (FIG. 3). 
     From this position of the mechanism, the user of the timepiece can either make the chronograph running again or reset the hands 8 and 28. Thus, the chronograph is of the type called as a &#34;three functions chronograph&#34;. In the first case, it acts on the pusher 25, bringing the mechanism into the position of FIG. 2, while, in the second case, it acts on the pusher 43, moving the retaining lever 40, the displacements of which are no more prevented by the arm 14a of the lever 14, that releases the beak 37d of the resetting lever 37 which, under the action of its return spring 39, rotates in the counter clockwork direction, acting on the two hearts 10 and 30, thus resetting the hands 8 and 28. 
     As a modification, the shaft 7 carrying the chronograph hand 8 could be hollow and the shaft 2 of the basis clockwork, carrying the wheel 13, could be prolongated through this hollow shaft and carry a &#34;trotteuse&#34; seconds-hand rotating above the hand 8. 
     It is to be noted, while referring specially to FIG. 4, that the present invention permits to transform easily a conventional watch, such as the watch the clockwork of which has been designated by 1, which comprises only conventional time indicators (hours, minutes and, may be, seconds) into a chronograph watch, that is to say a watch comprising indicators the running of which can be interrupted and re-established at will. 
     To this effect, one will eliminate the conventional dial of the watch 1 and one will place on the clockwork of this watch, at the place of the dial, the frame of the auxiliary mechanism comprising the two base-plates 3 and 4. In the case where the shaft 2 of the gearing of the clockwork 1 carries, initially, a hand, for instance a small seconds-hand situated out from the center of the watch, one will eliminate this hand and replace it by the wheel 13. Obviously, the conventional elements of the watch carrying the hours, minutes and seconds hands, in the center, must be prolongated so as to extend beyond the dial 5 carried by the auxiliary mechanism. If the shaft of the gearing of the clockwork 1 used as power point for driving the supplementary indicating members, which can be coupled and uncoupled, does not carry any hand, it must also be prolongated so as to extend beyond the frame of the clockwork 1 for permitting the wheel 13 to be situated, in height, in the thickness of the auxiliary mechanism.