GB2086100A

GB2086100A - Mechanical Device for Setting the Time of a Watch with Analogue Time Indication

Info

Publication number: GB2086100A
Application number: GB8131825A
Authority: GB
Original assignee: Ebauches SA
Current assignee: Ebauches SA
Priority date: 1980-10-24
Filing date: 1981-10-22
Publication date: 1982-05-06
Also published as: FR2492999A1; DE3141050A1; FR2492999B1; JPS57100368A; CH642512GA3; JPS6355674B2; CH642512B

Abstract

The time-setting mechanism comprises a shaft 112 rotatably mounted in a tube 114 in the back 6 of the watch case. The inner end of the shaft is provided with a mutilated gear 118 formed with a recess 118a. The outer end is provided with an operating blade 116 mounted for pivotal movement about the axis X1, X1 by means of swivel pins 122, 122'. The outer surface 6a of the back 6 contains a seating 126 in which the blade can be held stationary in a folded back position. The gear 118 can mesh with a time-setting adjusting wheel 22 of the going train. When the blade is positioned in its seating, the shaft is in a datum position and the recess 118c of the gear 118 is opposite the adjusting wheel 22, thereby ensuring the disengagement of these two parts. In modified embodiments, the shaft 112 can be pulled out against a bias spring to disengage the gear 118 from the adjusting wheel 22, either for free return to the datum position or to bring into mesh with the wheel 22 a fully toothed wheel which turns the hands more rapidly. <IMAGE>

Description

SPECIFICATION Mechanical Device for Setting the Time of a Watch with Analogue Time Indication The present invention relates to a mechanical device for setting the time of a watch with analogue time indication.

More specifically, the invention is concerned with a mechanical time-setting device which is suitable for use in a watch of small thickness and which is no longer visible when the watch is worn on the wrist.

It is well known that mechanical watches are provided with an operating member for setting the time, which operating member usually also serves for winding up the watch. In the case where these two functions are performed by the same member, the operating member usually has the form of a control shaft or winding shaft which is slidable in the watch case and in the plate of the movement. This shaft, by means of a lever system, actuates a sliding pinion which, depending on its position, meshes either with the time-setting adjusting means or with the crown wheel on the winding mechanism. In order to enable the user to manipulate the shaft easily, the latter is provided with a winding head or crown which projects from the rim of the casing of the watch.

In the case of electronic watches with analogue time-indication, the time setting of the watch can be effected by means of one or more push buttons which protrude from the circumferential wall of the watch. In this same case, the time setting can equally well be effected by means of a rod which is slidable to several different positions, as is done for mechanical watches.

It is clear that, in general, the projecting part which forms the winding crown or the push button does not constitute the most decorative part of the watch. It is also clear that, in the case of a very thin watch, the winder or push button is relatively even more visible if the crown or push button retains the dimensions which make it easy to operate. It will therefore be advantageous to be able to accommodate this part in such a manner that it is not visible when the watch is being worn.

It is for this reason that certain electronic watches with analogue-time indication are provided in the back of the case with a small push rod which, when it is depressed, causes pulses to be transmitted to the electric motor. In the rest condition, the head of this push rod is flush with the outer surface of the back of the case.

However, in the case of very flat watches, the head of the push rod can have only a very small surface area. This makes manipulation thereof a relatively delicate operation, since it is necessary to look at the dial of the watch and operate the push rod simultaneously. Moreover, this solution is certainly not applicable to the control of mechanical watches.

Furthermore, there are in existence a certain number of watches in which the operating member serves only for setting the time. This is the case with mechanical watches having automatic winding means, in which the winding weight enables a manual winder to be dispensed with. This is also the case with electronic watches having analogue indicating means the only function of which is to indicate the time. It is also the case with mechanical watches if a separate operating means is provided for the manual winding. It is therefore clear that a device which ensures the operation of only the time-setting of the watch and which will not be visible is of real interest.

Accordingly a first object of the invention is to provide a device for time setting only, which is not visible when the watch is being worn by its user, and which does not cause any discomfort in achieving this end.

A second object of the invention is to provide a time-setting device which is easy to manipulate and which does not necessitate the use of a special tool.

A third object of the invention isto provide such a device which, in addition, is suitable for use in a very thin watch, for example a watch the overall thickness of which is less than 2 mm.

A fourth object of the invention is to provide such a device which is as suitable as possible for use in an automatically wound watch.

According to the present invention, there is provided a watch having analogue time indication and comprising a going train in a case with a back, and a time-setting key including a shaft mounted rotatably through the back, a blade for turning the shaft pivotally attached to the outer end of the shaft for movement between a swungout, operating position and a flush position in which the blade is received in a seating in the back, with the shaft in a datum angular position, and a gear on the inner end of the shaft which is so mutilated that it does not mesh with a wheel of the going train when the shaft is in the datum angular position, but does mesh with the said wheel upon rotation of the shaft from the datum angular position.

By virtue of this arrangement, it is clear that the time-setting device is wholly retracted into the back of the case except during time-setting periods. However, when the blade is in the swingout position, the user can easily adjust the time setting of the watch, since the blade projects a substantial distance outwardly from the back of the case. Moreover, the seating defines the rest position of the mutilated gear, thereby eliminating any risk of the going train being locked by the mutilated gear, without it being necessary to complicate the mechanism for this purpose.

The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a top view of a self-winding watch comprising a time-setting device in accordance with the invention; Figure 2 is a partial view of the back of the watch case showing the time-setting device; Figure 3 is a vertical sectional view of the timesetting key, taken on the line Ill-Ill of Figure 2; Figure 4 is a partial top view of the back of the case showing a first constructional form of the time-setting key; Figure 5 is a vertical sectional view of one of the wheels of the time-setting gear train, taken on the lineV-V of Figure 1; Figure 6 is a diagram illustrating the kinematics of the watch shown in Figure 1;; Figures 7a and 7b are two half views in vertical section of a second constructional form of the key in two different positions; and Figures 8a and 8b are two half views in vertical section of a third constructional embodiment of the key in two different positions.

Figure 1 shows, in top plan view, an extra thin self-winding watch provided with a time-setting device in accordance with the invention.

Furthermore, in this watch, the back of the case constitutes the plate of the movement.

A winding weight 10 comprising an oscillating mass 1 orb and an arm 1 Oa is mounted on the back 6 of the case for pivotal movement about a pivotal axis Y-Y'. The movement of the winding weight is transmitted to a toothed ring 12 by a set of two pawls. This ring is drivably connected to the ratchet wheel 14 of a spring barrel 20 by wheels 16 and 18. The spring barrel 20 is drivably connected to a hand-driving wheel 24 by a wheel 22. The hand-driving moving part 24 is in mesh on the one hand with a centre wheel 26 and on the other hand with a cannon wheel 28. The hand-driving wheel 24 is also drivably connected with a final gear train constituted by the wheels 32, 34, 36 and 38 which are rotatably mounted on a lower bridge plate 100.The escapement wheel 38 cooperates with a lever/balancewheel/hairspring assembly 30. Lastly, the watch includes an assembly 110 which constitutes a time-setting key.

The manner in which the watch functions, except during time-setting periods is as follows.

The pivotal movement of the winding weight 10 resulting from the movements of the watch causes the toothed ring 12 to rotate, always in the same direction, which thus winds up the spring of the spring barrel. The spring barrel, by means of the wheel 22 and the hand-driving wheel 24, imparts rotary movement to hands carried by the cannon wheel 28 and the centre wheel 26. The construction of the watch and its going train in particular are described in more detail in our copending application of even date No. 8131824 and Ser. No. (claiming priority from Swiss Patent Application 7 961/80-80).

Figures 2 to 4 show a first embodiment of the winding key 110. As shown in Figure 3, the key 110 comprises a cylinder 11 2 which extends through the back 6 of the case and which is rotatably mounted in a tube 114 formed as an integral part of the back 6. At its outer end, the cylinder 112 has a blade 116 which is mounted for pivotal movement about an axis X,, X,' perpendicular to the axis Y1,Y1, of the cylinder 112. At its inner end, that is to say at the end thereof which extends into the casing of the watch, the cylinder 112 is provided with a toothed gear wheel 118 the axis of which is coincident with the axis Y1, Y,'.

The blade 116 has, for example, the form of an isosceles triangle, the apex of which is extended by two arms 120 and 120'. The arms 120 and 120' are provided with cylindrical swivel pins 122 and 122'. The cylinder 112 contains the axial bore 11 2a. In addition, the outer end of the cylinder 112 is provided with two notches 11 2h and 112'b disposed along its axis X1, X,'. The swivel pins 122 and 122' are engaged in the notches 11 2h and 112'b. A bolt 124 is engaged as a force fit in the outer end of the bore 112a.

The head 1 24a of the bolt 124 cioses the notches 112b and 112'b. The swivel pins 122 and 122' are thus confined within the notches 11 2h and 112'b. The blade 116 can pivot about the axis X,, X,' when an external force is applied to it. In addition, the external surface 6a of the back 6 of the case is provided with a seating 126 which is of substantially the same shape as the blade 11 6.

Moreover, the depth of this seating 126 is substantially equal to the thickness of the blade 11 6. Thus, when the blade 11 6 is folded back to a flush position, that is to say when the blade is positioned in the seat 126, it does not project beyond the outer surface 6a of the back 6 of the case. Obviously, the same applies to the head 1 24a of the bolt 124. The flush position is the rest position. However, when the blade 11 6 is prised out to its swing-out position along the direction of the axis Y,, Y,', it is caused to project a substantial extent beyond the outer surface 6a of the back of the case. It is then easy to grasp it with the tips of the fingers in order to rotate the cylinder 112 about its axis Y,, Y,'. This is the operating position of the blade.

I must be added that the seating 126, which is offubstantiallyhhe same shape as the blade 11 6, ensures an accurate angular positioning of the cylinder about its axis Y1,Y11 when the blade 116 is engaged in the seating 126.

The toothed wheel 118 is mounted on the inner end of the cylinder 112 in the following manner. The end of the cylinder 112 has two parallel flats 11 2c and 11 2'c. The axial bore 11 8a of the wheel 11 8 has two corresponding flats 1 186 and 118'h.Theseflats 1 186 and 118'b cooperate with the flats 11 2c and 11 2'c on the cylinder so as to fix the cylinder 112 and the wheel for rotation with each other. The wheel 118 is retained on the cylinder by means of a bolt 1 29 which is engaged as a force fit in or screwed into the axial bore 11 :'a of the cylinder. When the blade 11 6 is swung out, it is possible to turn the toothed wheel 118 around the axis Y1, Y,', the cylinder 112 being substantially immobilised so far as translational movement in the direction of the axis Y1, Y1, is concerned.

As shown in Figure 1, the wheel 11 8 can also mesh with the wheel 22, which thus also serves as a means for adjusting the time setting.

However, the wheel 118 is a mutilated gear devoid of teeth over a part of its periphery corresponding to a recess 11 8c. It is to be noted that this recess 11 8c is opposite the movable part 22 only when the orientation of the cylinder 112 is such that the blade 116 can in fact be introduced into the recessed seating 126. This possibility occurs only in one single angular position of the cylinder 112 due to the fact that the arms 1 20 and 1 20' have inclined portions 1 20a, 1 20'a corresponding to the thickness of the head of the bolt 124. These prevent the blade being pushed into the recess when the cylinder 112 is displaced 1800 from the said one angular position.

Figure 6 shows the kinematics of the train of moving parts which enables the setting of the hands to be adjusted starting from the rotation of the wheel 11 8. The wheel 22 is constituted by two toothed wheels 22a and 22b. The wheel 22a is rigid with its arbor, whereas the wheel 22b is freely mounted on this arbor. A friction device F is interposed between the wheels 22a and 22b. The hand-driving wheel 24 comprises a toothed wheel 98 and a pinion 96 which are rigid with the arbor, while a second toothed wheel 1 30 is connected to the wheel 98 by a friction device F'.

The time-setting wheel 11 8 is in mesh with the toothed wheel 22a of the wheel 22. The wheel 22b is in mesh with teeth on the spring barrel 20, while the wheel 22a is in mesh with the toothed wheel 98 of the hand-driving wheel 24. Lastly, the toothed wheel 98 of this wheel is in mesh with the centre wheel 26, the wheel 130 is in mesh with the first wheel 32 of the final gear train and the pinion 96 is in mesh with the cannon wheel 28.

During normal operation (while no adjustment of the time setting is taking place) the friction devices F and F' lock together the wheels 22a and 22b on the one hand and the wheels 98 and 130 on the other hand. Moreover, the time-setting wheel 11 8 is then out of mesh with the wheel 22a. The movement of the spring barrel is therefore transmitted to the hand-driving wheel 24 and the movement of the hand-driving wheel to the final gear train.

In the case when the time setting is being adjusted, the wheel 11 8 is in mesh with the wheel 22a, but the opposing torque developed by the spring barrel is sufficient to interrupt the drive between the wheels 22a and 22b by overcoming the action of the friction device F. Consequently, the rotation imparted to the wheel 22a by the wheel 11 8 is not transmitted to the wheel 22b and the spring barrel is not driven thereby.

Likewise, the wheel 22a is in mesh with the wheel 98, but the opposing torque developed by the final gear train is sufficient to interrupt the drive between the wheels 98 and 130 of the hand-driving wheel 24 by overcoming the action of the friction device F'. Thus, the movement of the wheel 22a is not transmitted to the wheel 32 of the final gear train. Consequently, the action on the wheel 11 8 brings about the turning of the hands by means of the centre wheel 26 and the cannon wheel 28 but leaves the spring barrel 20 and the escapement mechanism 30 stationary.

Figure 5 shows one possible construction of the hand-driving wheel 24. This wheel is rotatably mounted on an arbor 92 which is engaged as a force fit on a projection 90 formed integrally with the back 6 (of the case). The wheel 24 comprises the pinion 96 mounted on the arbor 92 by means of a bearing 94. The pinion is provided with a peripheral set of teeth 96a and with a shoulder 96b located between theset of teeth 96a. The first toothed wheel 98 is engaged as a force fit on the pinion 96 at the level of the shoulder 96b. The second toothed wheel 130 is freely mounted on the body of the pinion 96 below the wheel 98.

The wheel 1 30 is held in position by a washer 1 32 engaged as a force fit on a second shoulder 96c of the pinion 96. The friction device F' is interposed between the wheels 98 and 130. It consists for example of a member having a large number of radial arms bent round alternately towards the wheel 98 and towards the wheel 130.

The time-setting key 110 shown in Figures 2 to 4 is very suitable if the time-setting adjustment is effected by causing the wheel 11 8 to rotate through a number of complete turns. Indeed, in this case, at the end of the time-setting adjustment, the recess 11 8c assumes a position opposite the wheel 22a and the wheel 11 8 is not therefore in mesh with the wheel 22a. If the desired accuracy of adjustment of the time setting is to the nearest one minute, this means that a 1/60th of a revolution of the centre wheel should correspond to one complete revolution of the pinion 11 8. Such a device for adjusting the time setting is entirely suitable for correcting the error in the indication of time due to the normal operation of the watch.However, a one hour change in the time belt would make it necessary to rotate the time-setting key 110 through sixty revolutions, which would be considered unacceptable by some users.

Accordingly Figures 7a and7b show a constructional variant of the time-setting key which partly overcomes this disadvantage. This variant includes a cylinder 112' similar to the cylinder 112 of Figure 3. On the outer end of the cylinder 112' is pivotally mounted the blade 116 which is identical to that in Figures 2 and 4. On its other end is mounted a first wheel 11 8' which is rigid with the cylinder 112'. The length / of the cylinder 112' between the pinion 118' and the (pivotal) axis Xr, X,' of the blade is greater than the length r of the tubular part 114. The cylinder 112' can therefore be displaced axially within the tubular part 114. A spring 134 has one forkshaped end which projects into a groove 1 12'din the cylinder 11 2'. Its other end is rigid with the back plate 6. The spring 134 tends to retract the cylinder 11 2' to the position shown in Figure 7a.

The inner end of the cylinder 112' extends beyond that of the pinion 11 8' and carries a second toothed pinion 136 which is rigid with the cylinder 112'. The pinions 118' and 136 have the same external diameter. The pinion 136 is provided with teeth uniformly distributed over its entire periphery. The pinion 118' is a mutilated gear with a reduced number of teeth, the remainder of its periphery constituting the equivalent of the recess 11 8c of the pinion 118 in Figure 4. The number of teeth on this pinion corresponds to one revolution of the centre-wheel 26 which produces the unit displacement of the minute hand, for example one minute. When the spring 134 is in the rest condition, the pinion 118' is opposite the wheel 22a of the moving part 22.If the cylinder 112' is pulled back by means of the pivoted blade 116, the pinion 136 comes opposite the wheel 22a and meshes with the latter. This is what is shown in Figure 7b. The teeth of the pinion 136 should obviously be cut so as to permit meshing engagement with the wheel 22a in the course of the axial movement of the cylinder 11 2'. Let it be assumed that n is the number of teeth of the pinion 118' and N the number of teeth of the pinion 136. It is clear that, if one revolution of the pinion 11 8' imparts to the minute hand an angular movement corresponding to one minute, one revolution of the pinion 136 will correspond to an angular movement of the hands of N/n minutes. The pinion 136 therefore enables a more rapid adjustment of the time setting when the correction to be made in the position of the hands is large.

The manner in which this variant of the timesetting adjustment operates follows clearly from the preceding description. In the rest condition, the blade 116 is folded back into its seating 126 which is identical to that shown in Figure 2 and, the cylinder 112' being returned to its raised position, the position of the pinion 118' which is without teeth will be opposite the wheel 22a. The pinion is maintained in this position by the cooperation of the folded back blade 116 with its seating 126. If he wishes to correct an error of a few minutes, the user raises the blade 11 6 and, without applying tension to the cylinder 112', rotates the latter a number of times corresponding to the desired correction. Then, he repositions the blade 116' in its seating. This is shown in Figure 7a.If the user wishes to make a more substantial correction, he exerts a pull on the cylinder 112', which brings the pinion 136 opposite the wheel 22a and, while maintaining this pull, he causes the cylinder 112' to rotate until the desired correction is obtained. This is shown in Figure 7b. Then, he relieves the tension and repositions the blade 11 6 in its seating 126.

It must be stressed that this second use of the time-setting mechanism is only exceptional, since it corresponds to a charge in time zone or to a restarting of the watch.

A third constructional form of the time-setting key is illustrated in Figures 8a nd 8b. This constructional form enables the time setting to be adjusted easily irrespective of the amount of displacement that has to be imparted to the hands, but, as in the first constructional arrangement shown in Figures 2 to 4, the key is provided with only one toothed wheel. In fact, the first and third constructions are very similar two each other; this is why, in Figures 8a and 8b, the references of the parts already present in the first constructional form have been used again without alteration. The cylinder 112" has a length which is greater than that of the tubular part 114 in which it can therefore slide.The inner end of the cylinder 112" is provided with a toothed wheel 11 8 identical to that of Figures 2 to 4, that is to say it has teeth distributed regularly over its periphery except in a region which is deprived of teeth and which has the form of a recess. The outer end of the cylinder 112" is provided with a pivoted blade 11 6 identical to that which is shown in Figures 2 and 4. When the blade 11 6 is introduced into its seating, the recess of the wheel 11 8 is opposite the wheel 22a. There is therefore no meshing engagement between the wheels 11 8 and 22a for this position.The difference from the first constructional form resides in the fact that the time-setting key can assume two different positions in relation to the direction of its axis Y1, Y,'. For this purpose, a spring 134, identical to that of Figures 7, has a first end which is rigid with the back 6 of the case and a second, fork shaped end which engages in a groove 1 12nod formed in the cylinder 112". In the rest condition, the spring 134 maintains the key in the retracted position as shown in Figure 8a. In this position, the wheel 11 8 is in the same plane as the wheel 22a.If a pull is applied to the key with the aid of the blade 11 6, the key assumes the "protruding" position shown in Figure 3b. In this position the wheel 11 8 is no longer opposite the wheel 22a.

The wheel 118 can therefore rotate freely without causing the wheel 22a to rotate with it. In this 'form of construction the number of teeth of the wheel 11 8 and of the moving parts 22, 24, 26 and 28 is such that one revolution of the pinion 11 8 produces an advance of the hands sufficient to ensure a resetting of the time after a limited number of turns of the time-setting key.

The manner in which this constructional form operates follows clearly from the preceding description. The user withdraws the blade 116 from its seating 126 and moves it to the operating position. Without applying tension to the cylinder 112", he rotates the key with the aid of the blade until the hands occupy the desired position. Then, the user exerts a pull on the cylinder 112" and, while maintaining this pull, he rotates the cylinder until the blade 11 6 is brought to the position where it can enter the seating 126.

Then the user releases the blade 11 6, thereby bringing the recess of the pinion 11 8 opposite the wheel 22a. It is then only necessary to fold back the blade into its seating 126, thereby maintaining the recess of the wheel 11 8 opposite the wheel 22a.

It will be seen that, whichever form of construction of the key is considered, the blade 11 6 serves a dual purpose. On the one hand, when it is in the operating position, it enables the time-setting wheel to rotate in order to effect the desired displacement of the hands; on the other hand, when it is positioned in its seating, it serves to locate the key so that the recess in the timesetting wheel is opposite the wheel 22a and furthermore it maintains the wheel in this position whatever shocks may be applied to the watch, which prevents untimely interruption of the operation of the watch.

The preceding description is concerned with a watch provided with automatic winding means and time-indication by means of hands. This is in fact the preferred field of application of the mechanical time-setting device which is the subject of the invention. However, the application of this device is in no way limited to this type of watch. The key can perfectly well be utilized in a mechanical watch in which the time is indicated by disks, only the time-setting gear trains possibly being different. It can equally well be utilized in an electronic watch in which, as is well known, the spring barrel is replaced by a stepping motor and the escapement is eliminated.

It follows from the description that the timesetting device makes it possible to obtain effectively results which are much desired. It must be observed in particular that, except during the time-setting periods, the time-setting key is completely withdrawn into the back of the case and that on the other hand, when the blade is protruding from its seating, it provides a sufficient handhold to enable the user of the watch to effect the adjustment of the time setting easily.

It must likewise be stressed that, in the second and third forms of construction, the extent of the axial movement of the key is small, thereby enabling it to be mounted in a watch of small thickness. Moreover, in these same cases, the spring 1 34 is acted upon only during very short periods and a small number of times, thereby limiting the stresses that are applied to it.

Finally, no machining is required in the guide tube for the cylinder 112, 112' or 112", which make this solution suitable for use in a watch of very small thickness, for example less than 2 mm.

Attention is drawn to our copending application of even date No.8131826, Ser. No.

(claiming priority from Swiss application 7963/80-1) which is concerned with a related form of time setting key arrangement.

Claims

1. A watch having analogue time indication and comprising a going train in a case with a back, and a time-setting key including a shaft mounted rotatably through the back, a blade for turning the shaft pivotally attached to the outer end of the shaft for movement between a swungout, operating position and a flush position in which the blade is received in a seating in the back, with the shaft in a datum angular position, and a gear on the inner end of the shaft which is so mutilated that it does not mesh with a wheel of the going train when the shaft is in the datum angular position, but does mesh with the said wheel upon rotation of the shaft from the datum angular position.

2. A watch according to claim 1, wherein the back has a guide tube for the shaft on its inside.

3. A watch according to claim 1 or 2, wherein the shaft is also axially slidable and resiliently biased into a retracted position in which the gear is aligned with the said wheel for meshing therewith, but being capable of being pulled out to disengage the gear from the wheel.

4. A watch according to claim 3, wherein a second gear on the shaft meshes with the said wheel when the shaft is pulled out, the second gear having teeth all round its periphery.

5. A watch according to claim 3 or 4, wherein the resilient bias on the shaft is provided by a leaf spring inside the case and having one end fixed to the back and the other end in the form of a fork engaging a groove in the shaft.

6. A watch according to any of claims 1 to 5, wherein the going train comprises a cannon wheel, a centre wheel, a final gear train, the said wheel of the going train and a further wheel, the said wheel of the going train comprising first and second frictionally coupled wheels and the further wheel comprising third and fourth frictionally coupled wheels and a pinion fast with the third wheel and in mesh with the cannon wheel, the first wheel being the wheel which meshes with the mutilated gear for time-setting and being in mesh with the third wheel, which is in mesh with the centre wheel, and the fourth wheel being in mesh with a wheel of the final gear train.

7. A watch according to claim 5, wherein the second wheel is driven by the source of motive power for the watch.

8. A watch substantially as hereinbefore described with reference to and as illustrated in Figs. 1 to 6 or these Figures as modified either by Fig. 7a and 7b or by Figs. 8a and 8b of the accompanying drawing.