A TIMEPIECE

Abstract: A timepiece includes analogue-type means for displaying the minute at a given moment, constituted by a hand (5) rotated at the rate of one revolution per hour by the mechanism of the timepiece, and digital-type means for displaying the hour at a given moment, comprising a rotating member (6) for displaying the figure indicative of the hour at a given moment and means for driving the display member (6) which are controlled by the timepiece mechanism and are adapted to rotate the member in jerks at intervals of one hour.

Description: The present invention relates to timepieces of the type comprising means for displaying the minute at a given moment of the analogue type and means for displaying the hour at a given moment of the digital type. Timepieces of the above type are known from IT 187 553, CH 133 500, CH 27838/538, DE 548 256, US 3 879 929, US 4 006 588 and FR 1 146 406. More specifically, the present invention relates to a timepiece of the type specified in the preamble of Claim 1. A timepiece of the aforementioned type is described in IT 187 553 which shows several different mechanisms for rotating in jerks a member for displaying the hours at a given moment. Each of said mechanisms is basically formed by a spring device and by a movable anchor device. During the passing of the hour, the spring device stores the energy necessary for the hourly jerk of the display member. The anchor device prevents the rotation of the display member during the passing of the hour but, at every change of hour, enables the display member to jerk into the new display position. In several embodiments disclosed in IT 187 553 the spring device includes a coil spring whose ends are connected to respective gears which are part of a train of gears connecting the display member to a shaft rotating at a rate of one revolution per hour and carrying a minute hand. IT 187 553 further discloses anchor devices comprising an anchor mounted for pivoting between two end positions and provided with two stop members adapted to engage engagement surfaces provided in equiangularly spaced positions on a ring gear connected to the display member in order to stop the display member in the position for displaying the hours at given moments. A disadvantage of the mechanisms shown in IT 187 553 consists in that the anchor device causes the display member to rotate in jerks also during anticlockwise rotation of the hand displaying the minutes for the adjustment of the time displayed on the watch. During such anticlockwise rotation, the anchor device holds the display member still until the minute hand completes a rotation. At the same time, the ends of the coil spring are caused to move with respect to each other in the sense opposite to the sense in which the coils are wounded and this causes an abnormal stress of the coil spring which makes the timepiece mechanisms very sensitive to adjustment of the time in the negative sense. The object of the present invention is to provide a timepiece mechanism of the above mentioned type, which enables the hour display member to rotate in jerks only during clockwise rotation of the minute hand and to rotate continuously during anticlockwise rotation of the minute hand, in order to avoid any abnormal stress of the coil spring when adjusting the time displayed on the watch. The present invention will now be described with reference to the appended drawings, provided by way of example, in which: Figure 1 is a schematic front view of a wrist-watch according to the present invention, Figure 2 is a schematic front view of part of the internal mechanism of the watch, Figures 3, 4 and 5 are sections taken on the lines III-III, IV-IV and V-V of Figure 2 respectively, on an enlarged scale, and Figure 6 is a view corresponding to that of Figure 2 which shows the mechanism in a different operative condition. The embodiment illustrated in Figure 1 of the appended drawings relates to a wrist-watch. The invention, however, is of course equally applicable to other types of timepiece. Similarly, the various details relating to the face and body of the timepiece may vary widely from those illustrated purely by way of example in Figure 1. With reference to this drawing, the watch according to the invention, generally indicated 1, includes a case 2 which, in the wrist-watch illustrated, is connected to a strap 3, and a face 4. In the watch according to the invention, the minute at a given movement is displayed analogically, according to conventional technology, by means of a hand 5 which is rotated at the rate of one revolution per hour by a watch mechanism situated within the case 2. The mechanism is not illustrated since it may be of any known type and does not fall within the scope of the present invention. Furthermore, the elimination of this mechanism from the drawings makes the latter more readily understood. The hour at a given moment, however, is displayed digitally by means of a member for displaying the figure indicative of the hour at a given moment, which rotates in jerks at intervals of one hour. In the embodiment illustrated, the display member is constituted by a disc 6 which rotates in jerks beneath the face 4 and carries on its main surface the figures indicative of the hour at a given moment. Still with reference to the embodiment illustrated, the front surface of the case 2 has an annular peripheral zone 7 surrounding the face 4 and having an aperture 8 through which the figure indicative of the hour at a given moment can be seen. Since, as already indicated above and described in more detail below, the display disc 6 does not rotate continuously, but in jerks separated by intervals of one hour, the aperture 8 may be of a size which is just sufficient to enable the figure indicative of the hour to be read. In fact, the figure does not become only partially visible as the hour passes. Naturally, the hour display member could also be of a different type from that shown by way of example in Figure 1. For example, the figures indicative of the hour at a given moment could be shown on a fixed disc and the display member could be constituted by a disc rotating above the fixed disc and having an aperture or slot of some shape which enables the underlying figures shown on the fixed disc to be read. With reference to Figures 2 to 5, the watch mechanism rotates a tubular shaft 9 for displaying the hour at the rate of one revolution per hour. According to conventional technology, the watch mechanism also drives a shaft for displaying the minute at a given moment, which passes through the tubular shaft 9 and is connected to the hand 5. This shaft is also not shown in the drawings, so as to make the latter more easily and quickly understood and again in view of the fact that the above arrangement corresponds to conventional technology. The tubular shaft 9 carries a gear 10 (formed integrally with the shaft 9 in the embodiment illustrated) which meshes with a gear 11 of larger diameter supported rotatably by means of a pin 12 supported in turn by two walls 13, 14 which are fixed to the case of the watch. The transmission ratio of the pair of gears 10, 11 is 1:4, so that the gear 11 completes a quarter of a revolution per hour. The disc 6 for displaying the hour at a given moment is constituted by a ring which is supported rotatably in the case, for example, by means of a plurality of peripheral support pillars (not illustrated), and which has a toothed inner edge 16. The toothed edge 16 meshes with a further gear 17 which is rotatably supported on the pin 12 independently of the gear 11. A coil spring 18 is operatively interposed between the gears 11 and 17. The coil spring 18 has its outer end 19 fixed to the gear 11 by means of a pin 20 and its inner end 21 mounted around the pin 12. Near its inner end, the coil 18 is also fixed to the gear 17 by means of a pin 22. The pin 22 also engages an arcuate slot 23 formed in the gear 11 and extending through an angle greater than 90°, as well as a similar slot 24 (Figure 3) formed in a fixed support wall 25. The hour shaft 9 also carries a disc 26 bearing a toothed sector 27 which obviously also rotates at the rate of one revolution per hour. At each revolution, the sector 27 meshes with a pinion 28 which is rotatably supported by the fixed walls 13, 29 (Figure 4) by means of a pin 30. The pin 30 is connected for rotation with a pinion 28 and carries an eccentric 31. The number of teeth of the toothed sector 27 of the pinion 28 is such that, for each passage of the sector 27, the pinion 28 completes half a revolution. The pinion 28 also cooperates with a resilient plate 15 (Fig. 2) having one end which is bent into a V-shape in contact with the pinion and its opposite end (not visible in Figure 2) fixed to the case. When the sector 27 meshes with the pinion 28, the latter rotates to cause the reciprocating movement of the plate 15 between the undeformed position illustrated and a position in which it is bent. When the sector 27 is not meshed with the pinion 28, the latter is held in a fixed position by the plate 15. The eccentric 31 of the pin 30 is engaged in a slot 32 in an anchor 33 pivotably mounted on the fixed wall 14 by means of an articulation pin 34 (Figure 4). In the embodiment illustrated, the anchor 33 comprises a plate having a first portion 35 articulated to the wall 14, as shown, by means of the pin 34 and provided at one end with a plate 36 fixed by means of a pin 37 and acting as a counterweight. At the opposite end, the main plate forming the anchor 33 has a second portion 38 situated in a plane which is offset from the plane of the portion 35 and having a slot which opens at the end of the plate so as to make the portion 38 substantially fork-shaped in plan. The two arms 40 of a substantially U-shaped resilient plate 41 are fixed by means of pins 39 to the two arms of the fork. The inside edge of the central part of the plate 41 defines - together with the slot in the portion 38 of the anchor 33 - the slot 32 which is engaged by the eccentric 31. The arms 40 of the resilient plate 41 can deform resiliently in a direction perpendicular to the plane of Figure 2 of the appended drawings. The toothed edge 16 of the hour-display disc 6 has raised tabs 42 formed by blanking and bending (see Figures 2, 5) in correspondence with six equiangularly-spaced zones. As a result of the rotation of the eccentric 31 in the slot 32, the pivoting anchor 33 is moved reciprocally between a first end position illustrated in Figure 2 and a second end position illustrated in Figure 6. In each of these two end positions, a respective arm 40 of the plate 41 is engaged with one of the tabs 42. The operation of the watch described above is as follows: as already indicated above, the minute at a given moment is displayed analogically, according to conventional technology, by means of the hand 5 which is driven by the minute shaft from the watch mechanism. The hour at a given moment, however, is displayed by the disc 6 which brings the various figures indicative of the hour successively into correspondence with the aperture 8 (Figure 1). With reference to Figure 2, during the passing of the hour, the gear 10 rotates clockwise, that is, in the sense of the arrow A in Figure 2, at the rate of one revolution per hour. This rotation causes a corresponding anticlockwise rotation, that is, in the sense of the arrow B in Figure 2, of the gear 11 at the rate of one quarter of a revolution per hour. The gear 11 entrains the outer end 19 of the coil spring 18 in rotation, whilst the inner end 21 thereof cannot rotate since the pin 22 fixes that end to the gear 17 which cannot rotate anticlockwise since it is meshed with the toothed edge 16 of the display disc 6. This ring gear cannot rotate anticlockwise since one of the tabs 42 is engaged with one of the two arms 40 of the resilient plate 41 (in particular, the upper arm illustrated in Figure 2). With the passage of the time following a change of hour, therefore, the display disc 6 is held in a fixed position and the user still reads the same figure in the aperture 8 of the watch. During the passing of the hour, the coil spring 18 continues to be loaded, slowly storing the energy which will be required to cause the jerk of the display disc 6 at the time when the hour changes. The position illustrated in Figure 2 corresponds exactly to the condition which occurs at a distance of 6′40″ from the next change of hour. When the hour elapses, the toothed sector 27 rotates the pinion 28 which,by means of the eccentric 31 and the slot 32, moves the pivoting anchor 33 from the position illustrated in Figure 2 to the position illustrated in Figure 6. As soon as the movable anchor has moved from the position illustrated in Figure 2, the arm 40 of the resilient plate which is in the upper position in Figure 2 is disengaged from the respective tab 42 to enable the anticlockwise rotation of the toothed edge 16. This rotation takes place practically instantaneously by virtue of the energy released by the coil spring 18 which had previously been loaded. The latter rotates the gear 17 and consequently the toothed edge 16 until the next tab 42 of the ring comes into engagement with the other arm 40 of the resilient plate 41, as illustrated in Figure 6. The instantaneous rotation of the ring 6 thus takes place through an angle of exactly 30°, so as to bring a new figure indicative of the hour at the given moment into correspondence with the aperture 8. The subsequent operation is similar to that described above and is repeated cyclically. Any device of known type adapted to rotate the gear 10 anticlockwise is used for the adjustment of the hour displayed on the watch. This device is not illustrated in the appended drawings since, as already indicated, it may be of any known type and does not fall within the scope of the invention. The anticlockwise rotation of the gear 10 causes a clockwise rotation of the gear 11. The gear 11 entrains the gear 17 in rotation by means of the coil spring 18, the pin 22 and the slot 23. The gear 17 in turn rotates the ring gear clockwise. The rotation is not prevented by the engagement of the tabs 42 on the arms 40 of the resilient plate 41, since the back of each tab 42 acts as a cam surface which causes the arms 40 of the resilient plate 41 to be raised and thus enables the tabs 42 to pass beneath the arms. The hour display disc 6 is therefore able to rotate continuously clockwise as a result of the drive imparted by means of the hour adjustment device.

Claims: A timepiece comprising a case (2), a timepiece mechanism situated within the case (2), and means driven by the timepiece mechanism for displaying the hour and the minute at a given moment, wherein: a) the means for displaying the minute at a given moment are of analogue type, the means being constituted by a hand (5) rigidly connected to a first gear (10) rotated at the rate of one revolution per hour by the timepiece mechanism, b) the means for displaying the hour at a given moment are of the digital type, the means comprising a rotating display member (6) for displaying the figure indicative of the hour at a given moment and means for driving the display member (6) which are adapted to rotate the member in jerks at intervals of one hour, c) said means for rotating in jerks the member for displaying the hour at a given moment comprise a spring device (10, 11, 17, 18) for storing, during the passing of the hour, the energy necessary for the hourly jerk of the display member, and a movable anchor device (27, 28, 31, 32, 33), which is independent of the spring device (10, 11, 17, 18), for preventing the rotation of the display member (6) during the passing of the hour but enabling it to jerk into the new display position and subsequently stop at every change of hour, d) said spring device (10, 11, 17, 18) includes: a second gear (11) connected to said first gear (10) and having a larger diameter than the latter, a ring gear (16) connected to the member for displaying the hour at a given moment (6), a third gear (17) connected to the ring gear (16) and coaxial with the second gear (11), a coil spring (18) having one end connected to the second gear (11) and its opposite end connected to the third gear (17), and wherein e) said movable anchor device (27, 28, 31, 32, 33) includes an anchor (33) mounted for pivoting between two end positions and provided with two stop members (40) adapted to engage, in the two end positions, respectively, engagement surfaces (42) provided in equiangularly-spaced positions on the ring gear (16) in order to stop the display member (6) in the positions for displaying the hours at geven moments, and an. eccentric transmission (31) driven by the timepiece mechanism for causing the pivoting of the anchor (33), characterised in that the engagement surfaces of the ring gear (16) are constituted by projecting tabs (42) formed in the ring gear (16) by blanking and bending, the stop members (40) of the pivoting anchor (33) being constituted by two resilient plates (41) which extend in a plane parallel to the plane of the ring gear (16) and can deform resiliently in a direction perpendicular to said plane, each of said tabs (42) having a stop surface which is adapted to engage with the resilient plates (41) during rotation of the ring gear (16) in the sense corresponding to the clockwise rotation of the minute-displaying hand (5) and a slanting surface adapted to deform the resilient plates (41) during rotation of the ring gear (16) in the sense corresponding to the anticlockwise rotation of the minute-displaying hand (5). A timepiece according to claim 1, characterised in that the common axis of the second and third gear (11, 17) is offset from the axis of the first gear (10) by a distance such that the second and the third gear (11, 17) each mesh directly with the first gear (10) and, respectively, with the ring gear (16). A timepiece according to claim 1, characterised in that said eccentric transmission (31) comprises a pinion (28) freely rotatably mounted in the case (2) of the timepiece, a toothed sector (27) entrained for rotation with the first gear (10) and adapted to rotate the pinion (28) by half a revolution for each revolution of the first gear (10), and an eccentric carried by the central pin (30) of the pinion (28) and engaged in a slot (32) in the pivoting anchor (33).

Inventors: PERUCCHI, NORBERTO
Applicants: GIANNI BULGARI S.P.A.
Application year: 1989
Main classification: G04B19
IPC codes: G04B19