US3438196A - Quick-acting feed mechanism for day-and-date indicator means of timepiece - Google Patents

Description

April 15, 1969 KAZUO TERAMQTO ET AL 3,438,196

' QUICK-ACTING FEEDMECHANISM FOR DAY-AND-DATE] INDICATOR Q MEANS OF TIMEPIECE Filed April 19,196? Sheet 1 of a April 15, 1969 KAZUO TERAMOTO ETAL 3,438,196

' QUICK'ACTING FEED MECHANISM FOR DAY-AND-DATB INDICATOR MEANS OF TIMEPIECE Sheet 2 of 3 Filed April 19, 1967 FIG. 2

L X 1 204 20 4 I035 April 15, 1969 KAZUO TERAMOTO ET AL 3,438,196 I QUICK-ACTING FEED MECH SM FUR 1)AY--AND-- DATE INDI (-A'I'OR MEAN F TIMEPIECE Filed April 19 1967 1 .Sheet' 3 of 3 United States Patent 3,438,196 QUICK-ACTING FEED MECHANISM FOR DAY-AND-DATE INDICATOR MEANS OF TIMEPIECE Kazuo Teramoto and Yasnaki Nakayama, Tokyo, Japan, assignors to Citizen Tokei Kabushiki Kaisha, Tokyo, Ja an p Filed Apr. 19, 1967, Ser. No. 631,968 Claims priority, application Japan, Apr. 20, 1966,

1/ 36,785 Int. Cl. G04b 19/24 US. Cl. 58-58 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to improvements in and relating to a quick-acting feed mechanism for day and date indicator now broadly in use :with smaller timepieces, especially Watches.

Most of conventional indicator mechanisms of the above kind are fitted with jumpers and urging springs therefor, for positively positioning indicator members, preferably in the form of steppingly fed rotatable dials, at their rest or display position. A considerable drawback inherent in this type of positioning mechanism for day and date indicators resides in the unintentional movement of the indicators from their locked display position when subjected to external disturbing shocks, resulting in an incorrect calendar display of the timepiece which is fitted with the said indicators. In order to prevent this kind of conventional drawback from taking place, a person skilled in the art would easily and frequently think of the employment of stronger spring means acting upon said jumpers, so as to provide more positive and accurate operation of the locking mechanism for the latter. An employment of enough strong spring means for preventing the aforementioned possible lost motion of the calendar indicators by providing a more comprehensive checking effort against accidentally erroneous calendar displays, will necessitate a considerable additional amount of energy for driving the indicators, especially when they are driven from the regular gear .train of the timepiece. It should be noted in this case that the driving eifort for the calendaring operation amounts to a substantial amount, especially when the day-and-date or daily calendar change is carried into eifect in a quick mode. The necessary instantaneously delivered feed energy must be once accumulated in an accumulator, preferably spring means, in advance of its release at the very instant of the calendar change operation, so as to overcome the aforementioned large checking force. Therefore, a substantial increase of the checking force will invite a corresponding load increase of the timepiece movement, as well as possible fluctuation in the load torque imposed on the latter, which frequently causes a grave adverse effect upon the stepping accuracy and operating performance of the timepiece.

It is therefore the main object of the invention to provide a quick-acting feed mechanism for day and date indicator means of timepieces, capable of operating in a 3,438,196 Patented Apr. 15, 1969 ICC positive and accurate manner, yet relying upon a smaller feeding force to be released onto said means.

Another object is to provide a feed mechanism of the above kind which is of simple design, easy to manufacture and economic in its productive cost.

These further objects, features and advantages of the invention will become more specific when read in view of the following detailed description of invention by reference to the drawings illustrative of a preferred embodiment of the invention which is therein disclosed.

In the drawings:

FIGURE 1 is a somewhat schematic top plan view of a preferred embodiment of the invention, the illustration being partially omitted and broken away.

FIGURES 2 and 3 are sectional views taken substantially along cutting lines IIII and IIIIII in FIGURE 1, respectively.

FIGURES 4 and 5 are partial views of FIGURE 1, wherein the date dial and date feed cam are shown in their different relative respective positions from that shown in FIGURE 1.

FIGURES 6-8 are several schematic views illustrative of different mutual positions between day star wheel and the driving cam therefor, for better understanding of the novel operation of the unique feed mechanism.

FIGURE 9 is a chart showing the working mode of said wheel and cam shown in FIGURES 6-8.

Now referring to the drawings, especially FIGURES 1-3, conventional hour wheel 10 is press-fit to pinion 11 so as to form a gear assembly which is mounted rotatably on canon pinion 200, said gear assembly being conventionally arranged to rotate a complete revolution per 12 hoursConventional center :wheel and pinion 201 is press fit to canon pinion 200 and in turn has rotatably mounted thereon a conventional sweep second pinion 199. Center wheel and pinion 201 is rotatably supported in bearing means provided in upper and lower plates of which the upper one denoted and the upper bearing 101 are only illustrated for simplicity.

Gear 12 is press-fit to feed finger 13 and the resulted assembly is rotatably mounted on the plate 100 by means of a shoulder screw 202. Gear 12 has a doubled tooth number relative to that of the pinion 11 and is kept in engagement therewith, so as to revolve a complete revolution per 24 hours. Feed finger 13 is adapted for engagement with one of the radial projection as at 14a formed on a rotatable star wheel 14 when the finger is brought into its operating position as shown in FIGURE 1.

Star wheel 14 is rotatably mounted on a boss 102 formed on plate 100 and prevented from slipping out from its working position by means of stepped screw 203 screwed into said boss. Jumper 15 and an intermediate wheel 24 are separately and rotatably mounted on a boss 207 formed on plate 100 and held in position by means of a screw 208 screwed into said boss 207. Jumper 15 is formed with straight edges 15a and 15b and a kind of angular apex at the intersecting point of the latter. Jumper spring 16 has a longer arm- 16a and a shorter arm 16b and is held in position by means of fixing screw 122 studded to plate 100', although not shown. The longer arm 16a is kept always in pressure contact with jumper 15, thus urging the latter to turn in the clockwise direction in FIGURE 1 about its pivot 208, while the shorter arm 16b is kept in pressure contact with a stop pin 123 which is studded to plate 100, although not shown. Gear 17 is press-fit to the boss of star wheel 14 and kept in engagement with an intermediate gear 18. This gear 18 and a lever 22 are separately and rotatably mounted on a further boss 103 formed on plate 100 and prevented from slipping out from their working position by means of a cover 204, not shown in FIGURE 1,

which is held in position by a stepped screw 2% screwed into said boss 103. Gear 18 meshes with pinion 19 which is made integral with a date dial drive cam 20, thus forming a driver assembly which is rotatably mounted on a pin 125 press-fit to bell crank lever 22. Cover 204 serves for keeping the assembly 1.9 in position, of which the pinion 19 is kept in driving engagement with gear 18. Lever 22 comprises an arm 22a which is urged by a spring 23 to rotate in the counter clockwise direction in FIGURE 1. Spring 23 is mounted at its operating position by means of set screw 126 which is studded to the plate 100.

In the position shown therein, the semicircular periphery of disc 20a of the drive cam 20 is kept in pressure contact with one of the recesses 21b formed on the inner periphery of date dial 21, while another arm. 22b of bell crank lever 22 is kept in engagement with the periphery of eccentric cam 29, thereby an excessively strong pressure is being prevented from. acting upon the now engaging recess at 21b through basic disc 20a of driving cam 20. Date dial 21 is rotatably mounted on plate 100 by means of conventional mounting means, although not shown. Cam 29 is adjustable in its orientation by manually rotating its shaft part 29a which is made integral with the eccentric cam proper and press-fit in the plate 100 as shown in FIGURE 3. Although in several figures, came 29 is illustrated as if it is kept in contact with the outer periphery of date dial 21, this is only for convenience of drawing and both are separated from each other in practice. On the inner periphery of date dial 21, there are provided a number of notches 21a arranged alternately with said recesses 21b.

Gear 24 is kept in meshing engagement with gear 17, on the one hand, and with pinion 25, on the other hand, a cam 26 being rigidly united with the pinion. The cam 26 comprises a sector 26a having an arc extending within a peripheral range of about 150 degrees, a main projection or cam proper 26b, a recess 26c and an auxiliary projection 26a.

The day dial cam 26 is connected to pinion to rotate therewith which is rotatably mounted on a boss 100a which projects from the plate 100. Cam-and-pinion assembly 25-26 is prevented from slipping out from its working position by means of day dial 28.

Rotatable day star wheel 27 carries a day dial 28 fixedly and concentrically attached thereon and is mounted in turn loosely on the gear assembly 10-11.

Disc spring 128 is inserted between star wheel 27 and normal dial 131, for exerting a downwardly directing resilient force upon star Wheel 27, when seen in FIG- URES 2-3, so as to keep the latter in proper working position. As seen, the dial 131 is formed with date window 132 and day window 133 for the necessary calendar display.

Shaft projection 10% projects from plate 100 and mounts rotatably a conventional minute wheel pinion 129, only partially shown in FIGURE 2, which pinion is rigidly connected with conventional minute wheel 130, the former being in turn kept in engagement with said hour wheel 10. Therefore, when the regular time-keeping gear train, substantially not shown, yet including said pinion 129 and said wheel 130, is kept in motion, driving torque is transmitted from the gear train to hour wheel 10, in order to drive conventional time-indicating hands as well as the calendaring mechanism so far shown and described.

More specifically, wheel 10 and pinion 11 rotate in unison two complete revolutions, and gear 12 revolves a complete revolution per 24 hours, respectively, as already referred to. With the revolution of gear 12, feed finger 13 is also rotated in the counter clockwise direction in FIGURE 1 from the position shown therein and the finger will exert a torque upon one of the teeth or projections 14a kept in engagement therewith. The star wheel 14 is thereby rotated in the clockwise directi-on in the same figure, while the other projection such is at 14a will climb up along the edge 15a towards the apex 15c on jumper 15 for rotating the latter about its pivot 208 and against the urging action of spring 16 which is therefore further tensioned.

In the course of this operation, gear 17 is rotated slightly in the clockwise direction in FIGURE 1, and gear 18, pinion 1-9 and gears 24, 25 thus rotate in di rections illustrated by respective arrows shown therein.

Cams 20 and 26 are therefore rotated in the clockwise direction, but the date dial 21 is not driven until the driving projection 20]) will have engaged in the nearest one of notches 21a on the dial. In the course of this operation stage, the disc part 20a is kept in slidingly idle contact with one of the recesses 21b, and cam 26 also does not influence in any way the day star wheel 27.

With further counter clockwise rotation of the finger 13, the projection 14a of star wheel 14 will ride over the apex 15c of jumper 15 and slide down along the second straight edge 15]), thereby releasing the accumulated resilient energy in spring 1 6 and strongly urging jumper 15 to swivel about is pivot 208 in the clockwise direction. By this pivotal movement of jumper 15, the latter will push the same projection 14a so as to rotate the star wheel 14 together with gear 17 in the clockwise direction and in a sudden manner. Gear 25 meshing therewith is rotated correspondingly, as in the case of gear 18 above referred to.

With rotation of pinion 19 accompanying the cam 20, the driving projection 20b is brought into engagement with one of the notches 21a as already referred to and urges date dial 211 to quickly rotate it one pitch corresponding to of the entire periphery of said dial, for performing a date change. An intermediate step in the course of this quick date dial feed is shown in FIGURE 4.

'In the course of the above-mentioned date dial feed, the driving projection 20b is not in contact with the bottom of the related one of notches 21a, and therefore the lever 22 is prevented from its full pivotal movement, because, in advance of the realization of the latter the lever arm 22b is brought into contact with eccentric cam or adjustable stop 29. By adopting such stopper means, the date dial feed can be effected against a slightest possible frictional resistance acting on said dial by pressure contact of the disc portion 20a with recess 21b than otherwise encountered.

=With rotation of pinion 25 and cam 26 in the clockwise direction, the proper or main projection 26b will be brought into engagement with one of the radial projections 27b of star wheel 27 as illustrated by dotted lines 26b, 27b and urges star wheel 27 to rotate revcrsely a slight angle, say 10 degrees, and then to perform a counter clockwise rotation as shown in FIGURES 6 and 7. At an intermediate position of this feed movement of cam 26, second cam projection 26d is brought into engagement with a next following start projection at 27b", before the main cam projection 26!) leaves from contact with star projection 27b, as shown in FIGURE 7. Then, the feed of star wheel 27 is continued by the action of this second projection 260?, as shown in FIGURE 8, until the latter will have been disengaged from contact with the star projection 27b. Thus, star wheel 27 together with day dial 28 is fed just a pitch equal to of the whole periphery of the latter, carrying thereon symbols of seven days of a week, as only partially illustrated in FIGURE 1. After this predetermined step feed, the arc-shaped periphcry of sector 26a of cam 26 are kept in sliding contact with the opposite flanks of related two neighboring radial projections such as at 27b and 27b", for positioning positively the day dial 28 at its now appearing day display position.

'By manipulating a conventional means not shown, the date dial 21 can be forcibly driven to rotate in the clockwise direction for carrying out a date correction. In this case, cam disc 20 is displaced inwardly under the action of one or more projections formed at extremities of recesses 21b so that the rotation of date dial 21 may be performed with slight frictional resistance.

In the course of the date change operation, the lever 22 is held substantially at a constant position with practically no pivotal movement and thus the spring tension 23 is not altered in the practical sense, and practically no change in the driving torque for the date dial feed is produced. Therefore an important feature in designing the spring 23 is to make it strong enough to prevent any possible disturbance caused by unintentional outside force or shock.

In FIGURE 9, the operating mode attainable by the cooperation of feed cam 26 with day star wheel 27 is shown in the form of two charts. In the upper chart, the rotational angle, 0 of day star wheel 27 is plotted against the pivotal angle, 0 of the cam 2 6 measured from the position shown in FIGURE 1. In the lower chart, the \ratio T T wherein T denotes the rotational torque of feed cam 26 and T represents the torque transmitted to day star wheel 27, is plotted again against the same angle 0 In the upper chart, the angle 0 denotes an idle angle provided between the periphery of the main cam projection 2 6a and the cooperating tooth 27b of star wheel 27.

With gradual rotation of feed cam 26 from the position shown in FIGURE 1, and when the projection 26b is brought into contact with star wheel projection 27b as shown in FIGURE '6, the angle 0 becomes 120 degrees. In the lower chart, the ratio of torque transmission T /T becomes largest at 0 -=1 60'. As seen from the upper chart, the rotational angle 0 is in a reversed phase at this moment. With further increase of the angle 0 the torque transmission will become positive and then the value will reduce gradually. In correspondence thereto, the angle 0 then will vary gradually towards nil.

Upon crossing of @-curve with the horizontal axis, the positive value will gradually increase. At about Q ='240, the relative relation between cam 26 and star wheel 27 is substantially that shown in FIGURE 7. With further increased angle 0 the main projection 26b is brought into separation from the mating projection 27b of wheel 27, and the second projection 2601 will be brought into engagement with the next following wheel projection 27b, as was referred to hereinbefore with reference to FIGURE 7.

With still further increase of the rotational angle 0 the torque ratio is also increased and the wheel 27 travels a predetermined one pitch which corresponds to a 6 equal to 50 degrees. It should be noted however that the said two charts are only for illustration purpose and the details of the characteristic curves may be subjected to modifications depending upon the specific design of the double projection cam 26 and the star wheel 27 cooperating therewith.

We claim:

1. A quick-acting feed mechanism for day and date indicator for a timepiece, comprising a rotatable day dial as well as a rotatable date dial, day and date star wheels adapted to act upon said two dials and motion control means for said star wheels, wherein the improvement comprises motion control means for said day star wheel comprising in turn a combined cam having a main projection and an auxiliary projection, a part of the periphery of said cam with exclusion of said both projections serving for positively positioning said day dial by cooperation with its related star wheel; and motion transmitting means from one of said star wheels to said date dial comprising in turn a gear train and a second cam, a member of said gear train and said second cam serving for dual purpose to feed said date dial for calendar change operation and for accurately locking the date dial when the latter is to be kept at its display position.

:2. Feed mechanism as set forth in claim 1, wherein a pinion is provided concentrically and integrally with said combined cam, said pinion is operatively connected with a gear mounted concentrically, and press fit to said date star wheel.

6. Mechanism as set forth in claim 2, wherein said second cam is made integral with a member of said gear train and the thus formed assembly is mounted on a spring urged, pivotable lever.

4. Mechanism as set forth in claim 3, wherein said lever is a bell crank lever which is arranged to cooperate with an adjustable stop mounted on a plate of the movement of said timepiece.

References Cited UNITED STATES PATENTS 563,268 7/1896 Fazel 58-58 2,591,819 4/1952 Huguenin 5858 2,671,307 3/1954 Imhof 585'8 FOREIGN PATENTS 57,935 9/1953 France. 1,482,957 6/1967 France.

16,964 6/ 1898 Switzerland. 288,3-12 1/1953 Switzerland. 425,641 6/ 1967 Switzerland.

RICHARD B. WILKINSON, Primary Examiner.

G. H. MILLER, JR., Assistant Examiner.

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