US3667212A

US3667212A - Resetting-to-zero mechanisms for seconds, minute, and hour hands

Info

Publication number: US3667212A
Application number: US134944A
Authority: US
Inventors: Katsuhiko Komiyama; Yoshio Iinuma
Original assignee: Citizen Watch Co Ltd
Current assignee: Citizen Watch Co Ltd
Priority date: 1970-04-20
Filing date: 1971-04-19
Publication date: 1972-06-06
Anticipated expiration: 1989-06-06
Also published as: GB1347024A; FR2086198A1; DE2120170A1; CH566043A; FR2086198B1; CH570571A4

Abstract

In a timepiece wherein the second, minute and hour hands are rotated about a common axis, an externally operated hand position resetting arrangement is provided for shifting a second hand connection lever and a minute and hour hand correction lever into engagement with respective cams to accomplish the resetting of the hands to a zero position.

Description

United States Patent Komiyama et al.

[ 1 June 6, 1972 RESETTING-TO-ZERO MECHANISMS FOR SECONDS, MINUTE, AND HOUR HANDS Inventors: Katsuhiko Komiyama; Yoshio Iinuma,

both of Tokyo, Japan Assignee: Citizen Watch Company Limited, Tokyo,

Japan Filed: Apr. 19, 1971 Appl. No.: 134,944

Foreign Application Priority Data Apr. 20, 1970 Japan ..45 32975 June 4, 1970 Japan... WAS/55024 June 5, 1970 Japan ..45/55602 U.S. CL. ..58/74 Int. Cl. t r .....G04f 7/04 Field of Search ..58/74-78, 85.5

[56] References Cited UNITED STATES PATENTS 455,026 6/1891 Sandoz-Barbier ..58/76 843,887 2/1907 Gerson 58/74 2,679,135 5/l954 Hanhart ..58/76 Primary ExaminerRichard B. Wilkinson Assistant Examiner-George H. Miller, Jr. A!t0rneySughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT In a timepiece wherein the second, minute and hour hands are rotated about a common axis, an externally operated hand position resetting arrangement is provided for shifting a second hand connection lever and a minute and hour hand correction lever into engagement with respective cams to accomplish the resetting of the hands to a zero position.

5 Claims, 23 Drawing Figures ,PATENTEDJUH we 3,667,212

SHEET 2 [IF 8 PATENTEUJUH s 1972 3, 567. 212

SHEET 5 or 8 F|G.9A

FIGQB RESETT'ING-TO-ZERO MECHANISMS FOR SECONDS, MINUTE, AND HOUR HANDS This invention relates to a unique hands correcting or resetting mechanism for timepieces wherein by manipulating a certain operatable member to which access from outside is assured, the seconds hand of the timepiece is reset to zero and, at the same time, the minute hand is also returned to its regular position when it is positioned within a certain predetermined region, for example, about 12 or oclock of the timeindicating dial of the timepiece.

The conventional timepiece generally represents such a design that in order to set the time indication of the timepiece to an hourly'time-casting signal, as an example, the hour and minute hands must be operated regardless of the position of the seconds hand, thus occasional advancement or retardation of the latter being ignored and therefore a small time indication error occurn'ng almost each time for every time setting job. 1 K

For overcoming such conventional drawback, it is known to provide the timepiece with a stopper mechanism for the seconds hand. In this kind of timepieces, when it is desired to set the hands to an hour signal, the seconds hand is brought provisionally into stop by manipulating the stopper mechanism and mustbe started at the exact moment where the time-indication of the timepiece is in coincident registration with the exact time point. In addition, the seconds hand setting should be carried into effect in such a way that, generally speaking, the seconds hand must be stopped at the position of 12 oclock. Therefore, it may be said that this kind setting of seconds hand is highly inconvenient and thus has much to be desired. I

On the other hand, the conventional stop watch is provided with a resetting-to-zero mechanism by which it is possible to return its time-indicating hands to zero when desired. Such mechanism is also fitted in certain type of tachometer. But, it

should be noted that in the stop watch, it does not provide such possibility for returning the regular time-indicating hands to zero. On the other hand, the tachometer mechanism is substan tially different from the purpose and nature of the regular timepiece.

It is the main object of the invention to provide a unique hands position correcting or resetting mechanism for regular timepieces, substantially obviating the aforementioned conventional drawbacks.

These and further objects, features and advantages of the invention will become more apparentwhen read the following detailed description of the invention by reference to the accompanying drawings illustrative of several preferred embodiments of the invention.

In the drawings:

FIG. 1 is a schematic plan view of essential parts of a first embodiment of the invention, wherein, however, the timekeeping gear train and its related various mechanisms of a timepiece have been omitted from the drawing for the demonstration of the main principle of the invention.

FIG. 2 is an enlarged sectional elevation of main working parts of a conventional timepiece movement fitted with the hands correcting mechanism shown in FIG. 1.

FIGS. 3A and 3B are a part of the timepiece movement 'shown in FIG. 2 and in two different operational positions of said mechanism, respectively.

FIGS. 4A and 4B are schematic plan views, respectively, of a second embodiment of the invention and in two different operational positions of said mechanism.

FIG. 8 is an enlarged plan view of a fifth embodiment of the invention.

FIGS. 9A and 98 represent in combination a sectional elevation substantially taken along a broken section line P-Q shown in FIG. 8, the separation lines X-X showing that FIGS. 9A and 98 can be joined together by overlapping these section lines each other.

FIGS. 9C and 9D represent in combination a single sectional elevation taken substantially along a broken section line R-S shown in FIG. 8, the separation lines Y-Y showing that FIGS. 9C and 9D can be joined together by overlapping them into a single line; and

FIGS. 10A-10C are schematic plan views of a sixth embodimentof the invention shown in three different operational positions thereof.

Referring now to FIGS. 1, 2, 3A and 3B, the first embodiment of the invention will be described in detail hereinbelow:

Numeral 1 represents part of a conventional plate of a timepiece movement and 2 is a mounting plate for the gear train to be described, said mounting plate being arranged in parallel to the plate 1 and rigidly fixed thereto, although the fixing means have been omitted from the drawing only for simplicity. A stationary support member 3 is also fixedly attached to both

plates

1 and 2, although the fixing means have been omitted from the drawing again for simplicity. 4 represents an intermediate mounting plate shown only partially and attached rigidly to the

plates

1 and 2, although the fixing means have been omitted from the drawing.

5 represents a seconds hand arbor; 6 a seconds hands pinion; 7 a second gear; 8 a cannon pinion; 9 a cannon wheel; 10 a minute wheel; and 11 a third gear. These members 5-11 are arranged and mounted as conventionally relative to said parts 14 as is commonly known among timepiece engineers.

Numeral 12 represents a cam provided for setting-to-zero of seconds hand, not shown, said cam being formed into a heart Configuration when seen in FIG. 1 and fixed to arbor 5. A wire spring 13 is composed of a U shaped part and two parts standing up from the end of it as shown in FIG. 2. The U-shaped part of the wire spring 13 frictionally embracesa ring recess 6a formed on the seconds hand pinion, and the two standing parts pass through a slot 12a formed through the cam 12. By this spring bias arrangement, the cam 12 frictionally combines with the seconds hand pinion and is entrained with regular time keeping rotation of the latter.

A second cam 14 is formed with three separate vee-shaped notches 14a arranged radially at equal angular intervals and rigidly and concentrically to the minute wheel 10.

A lever 15 adapted for regulation of the position of cam 12 is pivotably mounted at its root end on the support member 3 by a studded pivot pin 16. At the free end of the lever 15, there is formed with a flat surface 15a, said lever being formed further with a recess 15b (FIG. 1) at an intermediate point between the both extremities thereof.

A ring piece 17, most clearly seen in its axial section in FIG. 2, having an inwardly and convexedly curved sectional configuration as at 17a, is rotatably mounted on a cam-position regulator pin 18 and kept in slidable contact with the lower surface of support member 3 and with the upper surface of the plate 1. The pin 18 passes through an elongated slot 3a formed through the member 3, the inwardly convexed bore 17a formed in ring member 17 and a further elongated slot 10 formed through the plate 1, representing the lower end 18c emerging downwardly from the last-mentioned slot la. As may be clearly seen from the drawing, regulator pin 18 can slide along and tilt in a vertical plane including the center of minute wheel 10. The pin 18 is formed with an enlarged part 18a which is positioned in proximity to the upper end 18b of the pin, thereby an excess axial movement thereof being positively limited within a predetermined small distance, said upper pin end 18b being kept in slidable engagement with said recess 15b, while the lower end of said pin is adapted for contact with the second cam 14.

There is provided a spring member 19, the root end of which is pivotably mounted on the member 1 by a pivot pin 23 in such a way that the ring member 17 is resiliently urged to move remotely from arbor 5.

An operating member 20 which is shaped into a slide or push button slidably mounted on the plate 1, although the mounting means have been omitted from the drawing only for simplicity. The inner end 20a of the push button 20 is brought into contact with the outer peripheral surface of the axially perforated ring piece 17. The push button may preferably be the conventional winding stem of the time piece. When the push button is pushed in, the ring piece 17 will be moved towards the seconds hand arbor 5 against the action of the urging spring 19. The conventional barrel spring is shown only partially by an imaginary line at 21.

The operation of the first embodiment so far shown and described is as follows:

When the push button 20 is pushed in, in the direction of an arrow A," it will drive the ring piece 17 towards the seconds hand arbor 5 when the second cam 14 occupies the position shown in FIG. 1 or a neighboring one thereto and regardless of occasional position of the first cam 12, thereby the regulator pin 18 being urged to shift in the same direction. Since, in this case, the upper end 18b of pin 18 is kept in engagement with recess 1512 on lever 15, the latter is rotated in clockwise direction in FIG. 1, while, at the same time, the lower end 18c of said pin 18 will enter into one of the vee-shaped notches 1.40 on second cam 14. It should be noted that except under such operational conditions that the conventional minute hand, not shown, and thus the second cam 14 do not occupy their position for representing the correct time, the lower pin end 180 is brought into contact with either wall surface defining a notch 14a. The related parts of minute wheel and cam position-regulating lever are so designed and arranged that the torque for turning the cannon pinion 8 by minute wheel 10 is substantially larger on account of its specific gear ratio than that necessary for rotating the lever 15 by the upper pin end 18b, the pin end 18c, upon contact with the notch wall 14a, will provisionally stop its advancing movement, while the upper pin end 18b will act upon the lever 15 to rotate it to a substantial degree so that the flat wall surface 15a of lever 15 will be brought into pressure contact with first cam 12 which is rotated in turn to a certain required degree. In this way, the spring 13 fixedly attached to cam 12 and frictionally embracing the ring recess 6a of seconds hand pinion 6 will be brought into slippage from pressure contact therewith so that the cam 12, regardless of its occasional position, is brought into its engaging position as shown in FIG. 1, thereby at first the seconds hand, not shown, being returned to its zero-position at 12 oclock indication point on the time-indicating dial, again not shown, and next, with the upper pin end 18b, having stopped at this stage for holding the seconds hand at its zero position, the pin 18 will be tilted in counter clockwise direction in FIG. 2 with the lower pin end 18c forcibly pushed into the related notch 144, so as to regulate the position of second cam 14 into such that the minute hand is returned to its regular position such as the zero position. At the same time, minute wheel 10' will act upon cannon wheel 9 which will influence upon the hour hand, not shown, so as to occupy the correct time.

As will be easily understood from the foregoing and by consulting with FIG. 3A, the operational range for setting of the minute hand to its correct position when it is near the correct time in either a plus or minus direction relative to the regular time-keeping position, may be defined by properly selecting the dimension of the vee-notches 14a, especially the outwardly diverging angle thereof. When considering, however, the purpose and object of setting the minute hand to its correct position, a certain, relatively small range of time indication, on opposite sides of its regular position, will do for the desired purpose.

It will be further observed from the foregoing that by pushing the button 20 to a lighter degree, the seconds hand only can be reset to zero.

Now, it is assumed that the second cam 14 occupies a certain different position than that shown in FIG. 1 at the time of push-in of the operating button member 20, wherein the lower end 180 of pin 18 is kept in contact with the peripheral surface of cam 14 so that it can not enter into any one of the notches 14a. Under these conditions, a push upon the pin 18 will swivel the latter in the plane including the drawing paper and in clockwise direction about the lower end oi" said pin, as shown in FIG. 3B so that the upper pin end 18b only is effectively moved to shift the lever 15 for resetting the seconds hand to zero. i

Upon release of the finger pressure from push button 20, a certain biasing member such as a spring, not shown, will act upon and the button 20 will be returned to its original position. Thus, lever 15 and ring piece 17 will be returned to their respective starting position under the action of spring 19.

Next, referring to FIGS. 4A and 4B, the second embodiment will now be illustrated. v i

In these figures, numeral 101 represents a stationary timepiece member such as conventional plate or the like; 102 a first cam similar to that shown at 12 in the foregoing and attached to seconds hand arbor 103; 104 a second cam similar 7 to that shown at 14 in the foregoing and fixedly attached to the minute wheel, not shown; 105 an intermediate lever which is pivotably mounted at an intermediate point between its both ends by a pivot 106 on the base plate 101 and having a pin 107 at its one end and a further pin 108 positioned between the said one end and the pivot 106; 109 a member similar to that shown at 20 in the foregoing and having its inner end 109a adapted to establish a pressure contact with pin 108 when it is pushed towards the seconds hand arbor, so as to rotate the lever 105 in counter clockwise direction; and 1 10 a first camposition regulating lever which is pivotably mounted by a pivot 111 on the base plate 101, having at its one end straight end edge 1 10a and two separate arms 11% and 1 10:; at its opposite end and defining a recess 110d formed thereby and therebetween, thus representing a twin fingered fork portion. The recess 110d thus formed is always kept in engagement with the one end a of the intermediate member 105 and one of the fork fingers l10b is formed with a curved surface 1l0b having a radius equal to the distance as measured between the pivot point of said lever 105 and the tip end 105a thereof. This lever is adapted for resetting the seconds hand to its zero position, as will become apparent as the description proceeds. v

Numeral 112 represents a second cam-position regulating lever for correcting of the minute hand, said lever 112 being pivotably mounted with its one end on base plate 101 by means of a pivot 113 and with its opposite end 112a adapted for engagement with one of vee-notches 104a formed on second cam for correcting the hour and minute hands as before, when this lever is rotated in counter clockwise direction; 114 a spring one end of which is fixedly attached to said base plate 101, the opposite end 114b of said spring being kept always into engagement with said lever 112 which is thus urged to rotate in clockwise direction. In the latter case, motion will be transmitted from lever 112 through pin 107 engaging therewith, to said intermediate or motion transmission lever 105 so as to rotate the latter in clockwise direction. Motion will be thence transmitted further to lever 110, so as to rotate it in counter clockwise direction. Numeral 115 represents a stop member adapted for limiting the range of counter clockwise rotation of the lever l 10.

The operation of the second embodiment is as follows:

When the operating member 109 to which access is made easily from outside as before, is pushed in as shown by an arrow A, the inner end 109a thereof will be brought into pressure contact with pin 108 and motion will be transmitted therefrom to motion transmission lever 105 which is thus caused to swivel around its pivot 106 in counter clockwise direction. In this way, the end 110a of lever 110 is brought to its certain predetermined position for performing said resetting. On the other hand, lever end 105a is released from engagement with recess 110d and then brought into contact with the curved portion 11% of the forkfinger 110b. At this operational stage, lever 112 is acted upon by spring 114 and thus moved to rotate so much by the pin 107 on lever 105. At this time, the end 112a of lever 112 has not yet brought into engagement with cam 104 (refer to FIG. 48). I

When the cam 104 occupies within a certain operational range corresponding to a certain time-indicating range of the minute hand around the correct time indication and under these conditions, a finger effort is applied to the manually operatable member 109 being further pushed in, lever end 105a will be caused to slide along the curved surface 110b on fork finger lb and the pin 107 will act upon lever 112 against the action of spring 1 14, thus this lever being caused to rotate in counter clockwise direction. In this way, the end 112a of lever 112 will invade into the recess 104a on second cam 104 and brought into pressure engagement therewith, so as to regulate the position of said cam adapted for performing the required correcting operation for the minute hand, not shown. In this way and as in the same way as before, the hour hand, not shown, is brought into its correct time-indicating position.

By releasing the operators finger pressure from the operating member 109, spring force at 114 will become effective to return first and second cam-regulating levers 1 10; 112, motion transmission lever 105 and operating member 109 to their respective starting position (refer to FIG. 4A).

Should the minute hand be positioned outside of the predetermined correcting range, the operating member 109 is further pushed in to its second operational position upon completion of the zero-resetting of the seconds hand, thereby the lever end 112a being brought into engagement with cam 104 at its plain peripheral surface other than the .vee-notches 104a and thus no correcting operation of minute hand is initiated in any way.

' In the foregoing first and second embodiments, the second cam has been shown as rigidly attached to the minute wheel, as a representative.embodiment. It will be seen, however, the invention is not be limited thereto. In practice, however, the cam can be fixedly attached to any selected one of related gears with minute wheel For instance, it can be attached with setting wheel, cannon pinion or the like member constituting the minute-indicating gear train 'part system. In this case, the vee-notches must be modified correspondingly in its number, size and the like design data. I

Next, referring to FIGS. 5A,"5B, 5C, 5D and 6, the third embodiment of the invention will be described in detail.

In this arrangement shown, the timepiece may either be of the electronic or mechanical one. In the former case, it is assumed that power is fed from a balance wheel to the gear train. In the latter case, power may be transmitted through the third or the line wheel to the gear train.

In this embodiment, numeral 230 represents the conventional plate; 222 a mounting plate for the gear train; 223 an intermediate mounting plate; 225 a seconds hand pinion mounted on seconds hand arbor 244; 216 a third wheel; 217 a fourth wheel; and 218 a second wheel which rotates in unison with second wheel shaft 219 in the regular time-indicating operation, yet there being a relative slip therebetween during resetting-to-zero of the minute hand, not shown. As inthe foregoing embodiments, the both

members

218 and 219 are frictionally coupled together and rotatable in unison with each other for a turning torque below a certain predetermined value.

Numeral 240 represents a cannon pinion; 221 a cannon wheel, 222 a minute wheel; 233 a first cam having a heart cam configuration as before and adapted for resetting-to-zero of the seconds hand, not shown; 244 the seconds hand arbor as above referred to. Numeral 224 is an urging spring attached to said cam as before; 226 a wheel adapted for carrying out the resettingfto-zero of theminute hand, not shown and attached fixedly with a second cam 215 having vee-notches 215a as before on its outer periphery and adapted for perfonning the resetting-to-zero, and further with a gear 227 adapted for the same purpose. Numeral 228 represents a second gear wheel fixedly attached to second wheel shaft 219 and kept always in meshing with said gear 227 so as to perform the minute hand resetting.

A lever 201 adapted for perfomiing the minute hand resetting, is pivotably mounted with its one end 201a on a base plate such as conventional plate or mounting plate as before, by means of a pivot pin 202 studded thereon. This lever 201 is formed with a bent-down straight edge part 201b, a rounded projection 201C adapted for cooperation with cam 215, an arc-shaped part 201d having a radius extending from the pivot point of said lever; a straight edge part 201s neighboring to said part 201d, a rear curved part 201f and an arm part 201g. Numeral 203 represents an operating member which has an easy access from outside and is adapted for cooperation with said part 2011). A lever 204 is used for performing the resetting-to-zero for the seconds hand, not shown and pivotably mounted on the base plate 230 by means of a pivot 205 studded thereon, said lever being provided with an inclined straight part 104a, and further with a pin 206 and a bentup straight edge part 204k adapted for cooperation with arc-shaped part 201d and a rear curved part 201i. The lever 204 is further provided with a straight edge part 204c on its opposite end for cooperation with cam 233. An urging spring 207 is provided the root end 207a of which is fixedly attached to the base plate 230 by meansof a fixing pin 209 and a set screw 208 as shown, while the free end 2071: of the spring is always kept in engagement with the projecting arm 201g of lever 201, thereby the latter receiving a resilienturging force for turning the lever in counter clockwise direction. At the same time, a resilient urging force is transmitted therefrom through the bent-up part 204b of said lever 004 kept normally in engagement with rear curved part 201 f of lever 201 to that 204, the latter being urged to rotate in counter clockwise direction. On the base plate 230, there is fixedly mounted a stationary stop pin 210 adapted for limiting the counter clockwise rotational range of said lever 204.

The operation of the third embodiment is as follows:

When the operating member 203 is pushed in as before and as hinted by an arrow A", the inner end 203a thereof is brought into pressure contact with the bent-down straight edge part 20lb of lever 201, the latter being swivelled thereby about its pivot 202 in clockwise direction and the straight edged end part 2012 of said lever 201 being brought into pressure engagement with pin 206 on the lever 204, so as to rotate the latter lever in clockwise direction. In this way, the straight edge part 2040 of lever 204 isbrought into cooperating engagement with'cam 233, thereby the latter being regulated to occupy a certain predetermined position adapted for making a resetting-to-zero of seconds hand, not shown. Until this time, the pin 206 on lever 204 has been brought into pressure and cooperative engagement with arc-shaped part 201d having a radius of curvature, equal to the distance extending from pivot point 202, upon slippage from contact with said part 2012, while the lever 201 adapted for resetting-to-zero of the minute hand, not shown, has not yet been attained such position that the rounded projection 2010 is brought into engagement with cam 215 (refer to FIG. 5B). 1

When it is assumed that the cam occupies such position that the minute hand is positioned within a predetermined range of time indication about the correct time position as its center, and the operating member 203 is further pushed in, the lever 201 is caused to rotate in clockwise direction, butthe lever 204 is kept stationary at the present position by virtue of the engagement of said pin 206 with said arc-shaped part 201d having its center positioned at the pivotal point of said lever 201. At the same time, the projection 201a of lever 201 will invade into the vee-notch2l5a and brought into cooperative engagement therewith, thus the cam 215 being checked to remain its position adapted for perfomting the setting-to-zer'o of minute hand. Therefore, motion is transmitted to second gear wheel 228 for the zero-resetting and the minute hand is brought to its zero position. Motion is transmitted from minute wheel 222 to cannon wheel 221 so as to rotate the latter for indicating the correct time (refer to FIG. C). At this time, second wheel 218 kept in mesh with the third wheel will make a frictional slippage relative to the center wheel (second wheel) arbor operatively connected through cannon pinion 240 with the minute hand as conventionally.

At a time-setting operation, minute wheel 222 is rotated so as to thereby rotate cannon pinion 240 and cannon wheel 221 for corresponding rotation of the minute and hour hands. During this time-setting operation, arbor 219 and pinion 240 are caused to rotate in unison and motion is transmitted through center wheel 228 mounted on the arbor 219 and provided for zero-resetting of the minute hand to the wheel 226, thereby the latter being brought into rotation. In this way, otherwise possible unintentional transfer of the related parts from the position destined for the resetting of minute hand to its zero position and caused by the regular time-setting operation can efiectively prevented. At this time, a slippage will occur between the arbor 219 and the gear 218, as in the case of the zero-resetting of minute hand.

Upon release of the operators finger pressure acting upon the operating member 203, spring force at 207 becomes effective so as to return the lever 201 for minute hand to its original position. At the same time, the lever 201 will act by its rear curved part lf upon the lever 204 for seconds hand at the bent-up part 204b, thus the latter lever being also returned to its original position (refer to FlG. 5A).

When the minute hand should be positioned outside the predetermined resettable-to-zero range; a further manual push-in pressure must be imposed upon the operating member 203 for shifting it to a second operating position upon returning of the seconds hand to its zero position. In this way, lever 201 is brought by its rounded projection 201:: into pressure contact with cam 215 at its outer plain periphery other than vee-notch 215a and therefore, the minute hand can not return to its zero position (refer to FIG. 5D).

Next,'referring to FIGS. 7A, 7B, 7C and 7D, the fourth embodiment of the invention will be described in detail. As will become clear from the description to be set forth, the foregoing levers for resetting-macro of seconds hand and minute hand, respectively, have been united into one member in the present embodiment. I

In these figures, the unified sole resetting-to-zero lever is shown at 301, one end 301a of which is pivotably mounted on a stationary base member of a timepiece movement, such as conventional plate 300 thereof, by means of a pivot pin 302 studded thereon. This lever 301 is formed with a projection 301b adapted for cooperation with cam 315 for resetting the minute hand, not shown, to its zero position; a stopper portion 3011) having an arc-shaped edge with a radius of curvature equal to the distance from the pivot 302 as its center and adapted for engaging contact with cam 313 for zero-resetting of the seconds hand, not shown, and for keeping the cam in its stationary position regardless of rotational movement of the lever 301; a curved actuating portion 301d adapted for initiating the zero-resetting of seconds hand; and a motion-receiving edge part 301e adapted for cooperation with the inner end 303a of a manipulating member 303 such as conventional winding stem. The lever 301 is further provided with a pin 304 fixedly mounted thereon and kept in pressure contact with an elongated spring 307.

. This spring 307 has its root end 307a fixedly attached to.

base plate 300 by means of a pin 309 passing forcibly through the spring, and a set screw 308. As briefly mentioned hereinbefore, the free end 307b of spring 307 is always kept in pressure contact with said pin 304, so as to urge the lever 301 to rotate in counter clockwise direction.

A stopper pin 310 is fixedly mounted on base plate 300 for limiting the range of counter clockwise rotation of the sole resetting lever 301.

The operation of the fourth embodiment so far shown and described is as'follows:

When the operator pushes the operating member 303 inwards as hinted by an arrow A', the inner end 303a thereof is brought into pressure contact with the sole reset lever 301 at its motion-receiving portion 301a so that the lever is rotated clockwise around its fixing screw 302. In this way, the portion 301d of lever 301 is brought into engagement with cam 313 which is regulated to its predetermined effective position adapted for perfomiing the seconds hand resetting. At this time, the cam 313 is kept in contact with the portion 301c of lever 301 and thus the projection 301b thereof is not yet brought into engagement with cam 315 for zero-setting of the minute hand (refer to FIG. 7B).

When the cam 315 occupies a position corresponding to the minute hand kept within its predetermined zero-resettable range, a further push-in operation of the member 303 will invite a further clockwise turning movement of the reset lever 301, thereby the actuating projection 30]!) invading into the vee-notch 315a on cam 315 which is thus checked against unintentional motion and held at its operative position. At this stage, the seconds hand resetting cam 313 is kept in engagement with the part 3010 of lever 301 and thus the seconds hand, not shown, is held in its zero-reset position (refer to FIG. 7C).

Upon release of the operators finger pressure fromv the reset lever 301, the spring force at 307 becomes effective to return the latter to its original position (refer to FIG. 7A).

'When the minute hand, not shown, is situated outside the predetermined resettable range and a further and slightly intensified finger pressure is applied to the operating member 303, the checking projection 3010 of lever 301 will naturally be brought into engagement with cam 315, yet with its plain peripheral surface 315b other than the notch 315a thereof. Therefore, the minute hand can not be reset to its zero position (refer to FIG. 7D).

It will be seen from the foregoing that the seconds hand reset lever and the minute hand reset lever can be provided ether in a separated mode or in a common and unified mode, as occasion may desire. The occasional adoption of an intermediate motion-transmitting member as referred to hereinbefore does not influence upon the nature of the present invention.

. Although not shown, an additional spring may be provided for the operating inember which spring acts upon the latter when the minute hand resetting means is not brought into the minute hand reset cam even upon execution of the zero-reset of the seconds hand. In such modified arrangement, the minute hand reset operationwill be encountered with a correspondingly stronger spring resistance than the case of the seconds hand resetting operation. Therefore, the operator can discriminate either manipulating operation only through his manual touch. Y i

In a further modification, again not shown, the cam configuration is so modified that the time setting may also be performed to any desired time other than those corresponding to the regular hour signals.

Next, referring to FIGS. 8, 9A, 9B, 9C and 9D, the fifth embodiment will be described hereinbelow in detail:

In FIG. 8, numeral 401 represents a rigid and stationary member such as conventional plate, balance wheel-mounting bridge or the like of an electronic timepiece movement, preferably the plate. Numeral 402represents a battery unit detachably mounted on the plate 401; Balance wheel is shown only by its outer configuration with an imaginary circle at 403, said wheel being mounted as conventionally on balance wheel arbor 418. Seconds hand reset cam 417 is attached at the center 415 of the timepiece onto a conventional seconds hand arbor 431, and in the similar way, minute hand reset cam 416 is attached to a conventional minute hand arbor 429 concentrically arranged to the former arbor 431. On the other hand, in proximity to the movement center 415 and to the balance wheel arbor 418, there are provided conventional escape mechanism and timekeeping gear train, including index wheel 420; sixth wheel 421; fifth wheel 422; fourth wheel 426; second wheel 425; third wheel 423 and minute wheel 424. These members are, however, designed and arranged as con- .ventionally and therefore, a detailed analysis thereof has been omitted only for simplicity.

The zero-reset mechanism according to this invention adapted for the reset of seconds hand and hour and minute hands is arranged at the diametrally opposite side relative to the conventional gear train and about an imaginary line connecting the center 415 of the timepiece movement with the axis of balance wheel arbor 418.

In these figures, a first cam 417 is arranged at the time-piece center 415 for performing the zero-resetting of the seconds hand, not shown. A substantially L-shaped lever 411 adapted for controlling the zero-resetting of the seconds hand is pivotably around a pin 411f mounted on, an intermediate mounting plate 430 near the root end of an urging spring 409 which is mounted on base plate 401, preferably the conventional plate of the timepiece movement, by means of

pins

410 and 411f which are studded on plate 401. Although the lever 411 is separated normally from said cam 417 as shown clearly in its full line position in FIG. 8, this lever is brought into cooperating contact with said cam during zero-resetting operation for the seconds hand, as shown by chain-dotted lines'in the same figure.

The longer arm 411b of lever 411 is formed at its free end with a straight edge portion 41 1a by which the lever is brought into cooperation with said cam 417, a projecting finger 411c and a shoulder 411d being formed at the bend of said L- shaped lever 411, so as to provide a curved recess 41le formed therebetween.

' A transmission lever 406 is pivotably mounted on the intermediate plate 430 by means of a pivot pin 405 studded on base plate 401. The opposite end of lever 406 extends to such a position where the inner end of an operating member 404 formed into a push button or conventional winding stem, as the case may be. An extension 406a is further formed on said lever 406, the free end of said extension extending into said recess 4112. With the reset mechanism positioned in its ofi service position, the free end of said extension 406a is kept in contact with said finger 411e, as demonstrated in FIG. 8 by full line.

Urging spring 409 is kept in pressure contact with a further lever 407 for hour and miriute hands, not shown, said lever 407 being partially and rigidly connected from below with transmission lever 406 by means of fixing

pins

405 and 408 in such manner that a clockwise urging force is transmitted to the combination of

transmission levers

406 and 407 rigidly connected with each other, so as to rotate this combined levers about the pin 405. These combined levers are kept in pressure contact with the inner end of operating member 404.

Transmission lever 407 is formed with an elongated arm 407a extending integrally therefrom and substantially radially and inwardly, the free end of this arm invading into a recess 414 formed on a hour and minute hands reset lever 413 which is pivotably mounted on the base plate 401 by pivot pin 412. Spring 409 acts upon the lever 407 so that the free end of arm 407a is kept normally in resilient pressure contact with one side wall partially defining said recess 414 as shown in FIG. 8.

A transmission lever 431 is rigidly attached with a transmission lever 407 for stopping the sixth wheel, andin such way that the both

levers

431 and 407 can perform a unitary swivelling movement around the pin 405. One end of lever 431 is kept in resilient pressure contact with a short arm 419e fonned on a stop lever 419 for stopping of the sixth wheel I representing a angular edged free end 4190 and is formed at its intermediate point with a projection 419d having substantially a triangular configuration.

The lever 419 is formed with an elongated spring arm 41% the free end of which is kept in resilient pressure contact with a stationary pin 401p studded on the base plate 401, the lever 419 being urged resiliently thereby always to rotate in clockwise direction and normally positioned at the shown position in FIG. 8 by balance with the reversedly urging spring force of the spring 409 which is transmitted to the lever through the short arm 419e.

It would be clear from the foregoing that under the action of spring 409 the combined assembly comprising various transmission levers 406; 407 and 431 is urged to rotate about pivot pin 405 in clockwise direction in FIG. 8, thereby the reset levers 41 1 and 413 and the stop lever 419 being normally positioned at their respective off-service position as shown by solid line.

The operation of the fifth embodiment so far shown and described is as follows:

In order to reset the seconds hand, minute and hour hands to zero position, the operator manipulates from outside the operating member 404, thereby the transmission levers being urged to rotate in counter clockwise direction against the action of spring 409 and the tip end of said extension 4060 of lever 406 within the inside space of recess 4112 until it is brought into pressure contact with the opposite wall 411d defining partially said recess. In this way, the lever 411 will rotate in clockwise direction about pin 41 1f, while the straight edge portion 411a of lever 411 is brought into pressure contact with cam 417 which is brought into rotation under the action of the lever 411 until the cam isbrought to its a predetermined position for resetting the seconds hand to zero.

At the same time, the elongated extension 407a of transmission lever 407 will act upon the lever 413 so as to rotate the latter in clockwise direction. In this way, the engageable end 412a of lever 413 is caused to invade into the vee-notch 416a formed on cam 416, providing that said end 4120 is positioned within its resettable range relative to said'notch. In this way, the minute and hour hands, not shown, are respectively reset to zero position and correct hour position.

On the contrary, when the cam 416 is so positioned that its vee-notch 416a can not be brought into cooperating contact with straight edge part 412a on lever 413, a manual push of operating member 404 will imitate a reset of the seconds hand to its zero position in the aforementioned manner, but the lever 413 is brought into contact with plain peripheral surface of cam 416 other than the vee-notch 416a, whereby the elongated extension 407a is slightly deflexed resiliently. Thus, a reset operation of the minute and hour hands can not be, therefore, brought about.

By the push-in manipulation of operating member 404, transmission lever 431 is caused to act upon lever 419 which is thus rotated and the straight edged lever end 4190 is brought into pressure contact with sixth wheel 421. In this way, this wheel 421 is caused to stop. It should be noted that on a certain intermediate shoulder 429a formed on minute hand arbor 429 (FIG. a seat ring 427 is mounted on this shoulder and the inner peripheral part of a perforated disc spring 428 is kept in pressure contact with the ring 427, while the outer periphery of the spring 428 is kept in pressure contact with second wheel 425, as most clearly be seen from FIG. 90. Cam 416 is fixedly mounted on minute hand arbor 429. After all, second wheel 425 is resiliently urged by said spring 428 against the cam 416, so the second wheel is therefore kept in frictional engagement with the shaft 429.

A friction engagement unit of the similar structure as above is also provided for the fifth wheel 422 shown in FIGS. 9c and 9D, although not specifically described.

The operation of the fifth embodiment of the invention is as follows:

From the foregoing, it will be clear that by the provision of friction unit between seconds hand arbor and minute hand arbor, on the one hand, and between seconds hand arbor and escape mechanism, on the other, the time-keeping hand reset operation can be performed without inviting excess stress in the time keeping and escape mechanisms, including balance wheel 403; sensing and drive coil assembly 430 only schematically shown by a chain-dotted-line block; and an index wheel 420 and the like conventional constituents. Therefore, a more easy and smooth seconds hand resetting to zero and those concerning the minute and hour hands can be brought about almost instantly and in an accurate and positive way.

' In FIGS. 9A and 9B which constitute in combination a single sectional elevation of the reset mechanism, including, as above mentioned, seconds hand reset cam; minute and hour hands reset cam; transmission levers adapted for actuation of these cams; sixth wheel stop lever; transmission lever cooperating therewith, for assisting better understanding of the invention in combination with FIG. 8.

As seen in FIG. 8, an elliptical member 418a is fixedly attached to the balance wheel arbor 418 and acts as a flange provided in turn with an impulse pin 418b. This elliptical flange 418a cooperates, during the hands-resetting operation, with the projection 419d on the longer arm 419a of sixth wheel stop lever 419 as schematically demonstrated by imaginary line in FIG. 8. This structure prevents effectively such a trouble that the balance wheel has been stopped at its neutral position and a next intended starting of the balance wheel can not be initiated.

In the electronic watch as shown and fitted with index wheel 420 in place of conventional anchor and conventional escape mechanism and operable in the reversed escapement principle where the drive force is supplied from the side of the escapement, and if theseconds hand reset lever is actuated sooner than the sixth wheel stop lever 419, rotation of fourth wheel 426 by the lever 411 will be transmitted to index wheel 420 and the teeth on the latter may be brought into strong pressure contact with the impulse pin, which would invite damages of these cooperating parts. It is therefore, in such type of electronic timepiece, very much desirable to let the sixth wheel stop lever 419 operate sooner than the seconds hand reset lever 411. On the other hand, when the lever 413 initiate its reset operation sooner than the lever 411, rotation of cam 416 will bring unintentional rotation of the seconds hand. If such an operation should occur, the operator would feed unpleasant feeling.

When, therefore, it is desired to initiate the rotation of cam 416 for minute and hour hands in advance of the realization of a cooperating engagement of second hands res'et lever 411 with its related cam 417, a positive slippage must be invited between cam 416 and second wheel 425. The aforementioned mechanism shown and described as the fifth embodiment of the invention will obviate the aforementioned defect. It should be mentioned that in the present embodiment, the slip torque at the fifth wheel 422, as converted into that appearing at the second wheel, is selected to be larger than that appearing at the second wheel 425.

Finally, referring to FIGS. 10A, 10B and 10C, the sixth embodiment of the invention will be described in detail hereinbelow:

This embodiment is exemplified as an electronic watch as in the case of foregoing fifth embodiment.

In the present embodiment, battery 502; balance wheel 503; seconds hand reset cam 506; minute and hour hands reset cam 507; time-keeping gear train constituents and frictional engaging units are of substantially similar design and arrangement as in the foregoing fifth embodiment. Therefore, the structure and operation of the reset mechanism proper are described below. Y

A minute and hour hands reset transmission lever 512 is pivotably mounted on base plate 501 by means of pivot pin 511, said lever being formed with a tip end 512a which is kept in engagement with a recess 510 formed on a minute and hour hands reset lever 508 and at the free end thereof. The lever 508 is formed with a slot 508a in which a plurality of pins 509 studded on base plate 501 may slide along. Therefore, thanks to this pin-and-groove guide means, the lever 508 is slidable in the direction of slot 508a.

Lever 512 is provided with a pin 517 studded thereon and a transmission lever 516 is pivotably mounted on this pin 517, said lever 516 having a tip end 517a kept in engagement with a recess 514a formed on seconds hand reset lever 514 of substantially L-shape at its bend thereof.

Base plate 501 mounts rigidly a pin 515 around which second hands reset lever 514 is pivotable. Arm 514a of said lever 514 has a straight-edged, free end extremity 514b adapted for cooperating with the seconds hand reset cam.

A return spring 518 is fixedly mounted on base plate 501 by

pins

515 and 518?. This spring 518 has an extension 518a, the end extreme 518b of which is kept in engagement with transmission lever 516 and in proximity to its pivot point 517, thereby urging the transmission levers 516 and 512 to rotate clockwise about pin 51 1.

Transmission lever 516 is kept in contact with operating member 504 formed into a push button. There is provided stop pin 520 on base plate 501 kept normally in engagement with the lever 514. These arrangements assure that the whole reset and correction mechanism so far shown and described is kept normally in the off-service position shown in FIG. 10A.

When push button 504 is pushed in,

transmission leversS

16 and 512 are caused to rotate in counter clockwise direction around pin 511 while keeping substantially the relative position of the related parts in the position shown in FIG. 10A. In this way, lever 516 acts by its end 517a upon lever 514 to rotate the latter in clockwise direction, thereby its tip end 514b being brought into pressure contact with cam 506 which is thus rotated for performing the corrective movement for the seconds hand. I

At the same time, transmission lever 512 is caused to rotate counter clockwise, whereby the minute and hour hands reset lever 508 is shifted in the axial direction of slot 508a and the free end of said lever being brought into engagement of cam 507 at its recessed part. In this way, a correction of the position of minute and hour hands is brought about as before.

When the cam 507 for correction of minute and hour hands position occupies such position as being offset from registration with vee-recess on the cooperable cam 507, a finger pressure imposed upon the push button will bring the end of the correction lever 508 into pressure contact with the plain periphery of the cam 507 other than the vee-recessand thus, the correction lever 508 will move no more and only the transmission lever 516 will be caused. to rotate in a counter clockwise direction around the pin 517 against the return spring 518. Therefore, the operation of the second hands reset lever can not be disturbed.

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:

1. In a center second type timepiece wherein a seconds hand, a minute hand and a hour hand are arranged at the center of the timepiece and power is supplied from the escape side of time-keeping gear train towards said hands, characterized by a hands position correcting mechanism comprising a first cam means and a first correction lever means related therewith and destined for correcting the seconds hand position and a second cam means and a second correction lever means related therewith and adapted for correcting the minute and hour hands position, an operating member accessible from outside thereto and adapted for actuation of said two lever means.

2. A hands position correcting mechanism as claimed in claim 1, wherein'said second cam means is adapted for performing a related correction job in a rather smaller range than that attributed for said first cam means.

3. A hands position correcting mechanism as claimed in claim 1, wherein said correction mechanism is so designed and arranged that the seconds hand is exclusively corrected in its position when a correction for minute and hour hands are not brought about.

4. A mechanism as claimed in claim 1, wherein said first cam means is in the form of a heart cam attached to seconds hand arbor.

5. A mechanism as claimed in claim 1, wherein said second cam means is mounted on minute hand arbor or a certain arbor operatively connected therewith.

Claims

1. In a center second type timepiece wherein a seconds hand, a minute hand and a hour hand are arranged at the center of the timepiece and power is supplied from the escape side of timekeeping gear train towards said hands, characterized by a hands position correcting mechanism comprising a first cam means and a first correction lever means related therewith and destined for correcting the seconds hand position and a second cam means and a second correction lever means related therewith and adapted for correcting the minute and hour hands position, an operating member accessible from outside thereto and adapted for actuation of said two lever means.

2. A hands position correcting mechanism as claimed in claim 1, wherein said second cam means is adapted for performing a related correction job in a rather smaller range than that attributed for said first cam means.