US3716983A

US3716983A - Calendar watch

Info

Publication number: US3716983A
Application number: US00155433A
Authority: US
Inventors: K Tanaka; A Tsuzuki; T Matsumura
Original assignee: Citizen Watch Co Ltd
Current assignee: Citizen Watch Co Ltd
Priority date: 1970-06-22
Filing date: 1971-06-22
Publication date: 1973-02-20
Anticipated expiration: 1990-02-20
Also published as: DE2131532A1; JPS515594B1

Abstract

This invention relates to the feed mechanism of the above kind, by which a plurality of calendar teeth are automatically fed at every end of small or even months, so as to obviate otherwise troublesome manual calendar feed operation to be carried out at such every month end above referred to. The improvement resides in the provision of a small month end driver rotatably mounted on said date dial and adapted for performing a complete revolution per month together therewith said driver being controlled in its position by said cam and in close proximity of every month end.

Description

a United States Patent 1 Tanaka et al.

[ Feb. 20, 1973 [22] Filed:

' 211 Appl.No.: 155,433

' [54] CALENDAR WATCH [75] inventors: Kazuo Tanaka, Akin-a Tsu'zuki,

Tetsuo Matsumura, all of Tokyo, Japan 73 Assignee: Citizen Watch Company Limited,

Tokyo, Japan June 22, 1971 [30] Foreign Application Priority Data 7 June 22, 1970 Japan ..45/54199 52 0.5. CI ..58/58 [51] Int. Cl. ..G04b 19/24 [58] Field of Search ..58/4, 5, 58, 59'

[56] References Cited UNITED STATES PATENTS 2,483,775 10/1949 Klaris ..58/5

5/1878 Paddock ..58/58 7/1896 Fazel ..58/58 2,286,000 6/1942 Neyhart ..58/5 2,709,885 6/1955 Van Kampen .,58/5 3,373,558 3/1968 Makiri ..58/58 X FOREIGN PATENTS OR APPLICATIONS 1,575,397 7/1969 France ..58/58 Primary Examiner-George H. Miller, Jr. Attorney-Richard C. Sughrue et a1.

[57] ABSTRACT This invention relates to the feed mechanism of the above kind, by which a plurality of calendar teeth are automatically fed at every end of small or even months, so as to obviate otherwise troublesome manual calendar feed operation to be carried out at such every month end above referred to.

The improvement resides in the provision of a small month end driver rotatably mounted on said date dial and adapted for performing a complete revolutionper month together therewith said driver being controlled in its position by saidcam and in close proximity of every month end.

3 Claims, 6 Drawing Figures CALENDAR WATCH This invention relates to improvements in and relating to the feed device for the calendar mechanism of a timepiece, especially watch. More specifically, it relates to the feed mechanism of the above kind, by which a plurality of calendar'teeth are automatically fed at every end of small or even months, so as to obviate otherwise troublesome manual calendar feed operation to be carried out at such every month end above referred to.

Almost all conventional calendar timepiecees are of such design that its date calendar dial is provided with a series of successive date numerals covering lst-3lst days of the large or odd month and the dial ring is fed daily by a step corresponding to a complete day or 24 hours under the regular operation of the timepiece movement.

Therefore, there is no problem when the calendar is concerned with a large or odd month. But the timepiece wearer must perform a manual operation at the end of a small month in the above conventional mechanisms. For obviating this conventional drawback, various automatic date calendar feed mechanisms have been proposed. A representative one of the above improved mechanisms, having a simplest design and structure comprises a specific wheel called date feed wheel which performs a complete revolution per 24 hours and so acts upon a lever pivotably mounted on the conventional plate of the timepiece movement, thereby said lever being driven for making a swivelling movement.

Operating range of this lever movement is controlled by a separate month discriminator cam, so as to allow the lever for feeding by its actuating end the calendar dial a lesser or largeramount depending upon the large or small calendar month.

Even with such simplest calendar feed mechanism as above, the pivotable lever has substantially large dimensions and requires a substantial space for performing its pivotal movement in combination with its related and cooperating mechanical parts. It is therefore highly difficult to use such conventional feed lever and its related parts in the smaller timepieces, especially watches which must be as small and thin as possible so as to meet with recent consumers demands. In addition, this conventional date feed mechanism is designed so that torque is transmitted from the date feed wheel through the pivotable lever to the date calendar-dial only with an inferior transmission efficiency. Further, in this conventional mechanism, the dailyregular date calendar feed is performed with a return spring attached to said lever being substantially deformed, thereby imposing a substantial counter load upon the timepiece movement. When this kind of month ends calendar feed mechanism is used with the generally ring-shaped date calendar dial, the pivoting complicated design of the feed mechanism to such a degree that the application thereof to a watch movement is again prevented.

It is a primary object of the invention to provide a calendar feed mechanism, capable of automatically feeding the date calendar dial by a necessary plurality of tooth steps at each end of smaller months.

A further object is to provide the calendar feed mechanism of the above kind, capable of arranging its main working parts substantially on a plane and the whole structure is highly simplified and represents the smallest possible number of constituent parts.

A still further object is to provide a calendar dial feed mechanism as referred to above, capable of being combined with the regularly adopted ring-shaped date calendar dial and applicable to the wrist watch movement.

. A further object is to provide the calendar dial feed mechanism of the above kind, capable of consuming very little energy for drive of the mechanism.

In order to fulfil the aforementioned objects, it is proposed according to the present invention to mount an actuator on the date calendar dial ring, said actuator being controlled in its operational range by a month discriminator cam, and a date feed member is mounted on the date feed wheel, said date feed member being engageable directly with the feeding teeth of said dial ring or with said actuator, for performing an automatic date feed at every termination of the end date of any one of the smaller months. In this respect, it should be understood that the term smaller months hereinused throughout the specification and in appended claims means February, April, June, September and November.

These and further objects, features and advantages of the invention will become more apparent when reading the following detailed description of the invention with reference to the accompanying drawings illustrating several preferred embodiments of the invention.

In the drawings:

FIG. 1 is a plan view of a first embodiment of the invention, wherein, however, several parts thereof are shown only partially and the full lines and dotted lines represent the constituent parts in their position occupied at the end of a smaller month, while the chaindotted lines represent the position of the actuator at the end of a large or odd month.

FIG. 2 is a similar view of FIG. 1, illustrating a second embodiment of the invention.

FIG. 3 is a similar view to FIG. 2, illustrating the second embodiment again and more specifically showing the feeding mode of the month dial.

FIG. 4 is a similar view to FIG. 1, illustrative, however, of a third embodiment of the invention in its relative position at the end of a smaller month.

FIG. 5 is a similar view to FIG. 1, illustrative of a fourth embodiment of the invention and showing the relative position of constituent parts at the end of a small or even month with exception of February.

FIG. 6 is a similar view to FIG. 5, illustrative of the fourth embodiment again and showing the relative position of the main working parts at the end of a large or odd month.

Referring now to FIG. 1, the first embodiment will be described hereinbelow. in detail.

In FIG. 1, the numeral I represents partially a conventional plate of a watch movement, said plate being shown in a highly simplified way several recesses and openings for attachment of several working parts not belonging to the inventive mechanism have been omitted for simplicity.

The reference numeral 2 represents a conventional month star wheel having twelve separate radial projections or teeth 2a and rotatably mounted on the plate 1 by means of a stud 1a. A month discriminating cam 3 is concentrically and fixedly mounted on the month star wheel 2, so as to perform a unitary rotation therewith. This cam 3 is a substantially circular disc'formed on its peripheral surface alternately with low and high cam edges 3a and 3b corresponding to the respective large or odd months which consist of January, March, May, July, August, October and December, and to the respective smaller months which consist of February, April, June, September and November. On the upper surface of the discriminator cam 3, there are provided numerals 1-12 radially arranged in radial registration of said projections or teeth 2a and in correspondence to the calendar months from January to December, respectively.

Star wheel 2 and discriminator cam 3 are made integral with each other by press fit, soldering, welding, bulging and hammering or riveting or the like conventional fixing procedure, so as to form, in combination, a month calendar dial 4 which is pivotably mounted on said plate 1 by means of stud 1a, as was described in the foregoing.

A jumper spring 5, only partially shown, has its root portion, not shown, fixedly mounted on the plate 1, the

hooked actuating end of the jumper being kept in pressure engagement with a pair of the teeth 2a in the form of a bridge as shown.

A date calendar dial ring 6 carrying thereon a series of radially arranged date symbol numerals l-3l which covers one of the large months, yet being shown only partially, is rotatably mounted as conventionally on the plate 1, although the bearing means necessary therefor have been omitted from the drawing on account of its very popularity. This dial ring 6 is formed inside peripheral teeth 6a corresponding to respective date calendar symbols 1-31. The dial ring 6 is provided fixedly with a month feed pin 6b and subjected to a spring pressure exerted by a jumper similar to that shown at 5, although not shown. This jumper is also fixedly attached at its root end on the plate 1 as before.

Numeral 7 represents a date feed member, preferably formed into a pawl which is mounted fixedly on a date feed wheel 8 which wheel is driven, as conventionally from the conventional time-keeping and time-indicating gear train, not shown, of the watch movement and performs a complete revolution per 24 hours, said pawl 7 and said wheel 8 being rotatably mounted on the plate 1 by a common stud 1b.

Month feed pin 6b is so designed and arranged that it engages with the teeth 2a on month star wheel 2 for performing one step feed thereof when the date dial 6 is fed from its 31st day display position of a certain large month to its 1st day display one of the next following month.

A small month end feed lever 9 is pivotably mounted at 6c on the rear surface of date dial 6, said lever having an end pawl 9a adapted for engagement with said date feed pawl 7. The feed lever 9 is further formed with a projection 9b in proximity to the opposite end to said end pawl 9a, said projection 9b being adapted for engagement with month discriminator cam 3 and said opposite end being formed into an elongated spring 9c which is kept in pressure contact with month feed pin 6b.

With pressure contact of end spring with month feed pin 6b, the lever 9 is resiliently urged to rotate counter-clockwise in FIG. 1, but this rotation is limited by contact with a circular and concentric shoulder 6d formed on the dial 6. This extremely rotated position of lever 9 is shown by chain-dotted line in FIG. 1.

With lever projection 9b engaging with one of high peripheral parts 3b on month discriminator cam 3, the pawl end 9a protrudes beyond the teeth 6a on date dial 6 and becomes ready for engagement with date feed pawl 7. On the contrary, when lever projection 9b is brought into pressure contact with one of low peripheral parts 3a on month discriminator cam 3, the pawl end 9a will recede from the foregoing protruded position.

The conventional time-indicating dial, not shown, is

formed as conventionally with a date symbol display window only schematically shown by chain-dotted lines at 10. In the similar way, the indicating dial is formed with a month symbol display window again shown schematically shown at 11.

At the lower left part of FIG. 1, the cross-sectional configuration of the date dial 6 is shown by chaindotted lines only for easy reference.

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

On any of the regular dates with exception of month end, the date feed pawl 7 which rotates a complete revolution per 24 hours in unison with date feed wheel 8 only schematically represented will drive the date dial 6 one tooth pitch per day (24 hours) by engagement with one of the teeth 6a, as conventionally by receiving motion from the regular time-keeping and time-indicating gear train of the watch movement, not shown, so as to display a proper and different date symbol per day through window 10. When the date symbol 30" becomes visible through date display window 10, smallmonth-end feed lever 9 is brought into engagement by its projection 9b with one of the peripheral parts on month discriminator cam 3. At the 30th day of a large month, the lever projection 9b is brought into engagement with a corresponding one of low peripheral parts 3a of cam 3, as shown in chain-dotted line in FIG. 1. In this way, the end pawl 90 does not protrude beyond the tooth 6a of date dial 6, the date displays 3 l and 1" will appear at the window 10 upon regular successive two daily feeds of the dial by engagement and feeding action of date feed pawl 7 with the respective teeth 6a as usual in the successive regular days and in the direction as shown by an arrow A" shown in FIG. 1. During the transient period from the 31st day of the month and the lst day of the next following month, month feed pin 6b will feed the month star wheel by a tooth pitch in the direction as shown by an arrow 8" shown in FIG. 1, thus the month display symbol appearing at the month-viewing window 11 being altered correspondingly to show the new calendar month.

At the 30th day of a small or even month such as April, the projection 9b will be brought into engagement with one of high peripheral parts 3b of cam 3, as shown in full and dotted lines in FIG. 1 and the end pawl 9a protrudes a certain distance beyond the dial tooth 60. Therefore, at the end of the 30th day, date feed pawl 7 will brought into engagement with the end pawl 9a, thereby the date dial 6 being fed two successive days, so as to change the date display from 30 of April to l of May.

It will be seen therefore that in the present first embodiment, the calendar must be manually adjusted at each end of February, regardless of the year being leap or regular one.

Next, referring to FIGS. 2 and 3, the second embodiment will be described in detail.

In this embodiment, numeral 101 represents a plate as at l in the foregoing and 102 shows a month star wheel which corresponds that shown at 2 in the foregoing. Inaddition, numeral 103 represents a month discriminator cam as at 3 in the foregoing. This cam 103 is formed alternatively again low and high

peripheral parts

103a and 103b and carries thereon twelve month symbol representations 1-12 covering a year round. Month star wheel 102 and month discriminator cam 103 are rigidly united together as before, so as to provide a month calendar dial 104 which is rotatably mounted on a conventional cannon wheel 150 constituting a member of the conventional time-keeping and time-indicating gear train, not shown, of the watch movement.

Jumper spring 105 is also provided which is similar in its design and operation to that shown at 5 in the foregoing.

Date dial 106, only partially shown, corresponds to that shown at 6 in the foregoing. This date dial carries thereon a series of date display symbols 1-31 covering a large or odd month as before, although not shown only for simplicity. Inside date feed teeth 106a corresponding to said date symbols 1-31 are also formed on the inside periphery of the date dial again as before. This dial 106 has a stepped cross-section as shown by numeral 106g.

Pins

1060, 106e and 106f and an opening 106d are provided on and in the date dial 106 as seen, the latter being naturally rotatably mounted on the plate 101, although its bearing means for this purpose has been omitted from the drawing for simplicity. This date dial is also kept in fed position by contact with a further jumper spring, although not shown.

Numeral 107 represents a date feed member as at 7 in the foregoing and preferably formed again into a feed pawl. This feed pawl 7 is fixedly mounted on the date feed wheel 108 which is similar in its structure and operation to that shown at 8 in the foregoing. This wheel 108 performs a complete revolution per 24 hours and adapted for daily feed of date dial 106 in the direction of an arrow D. Date feed wheel 108 and date feed 107 rigid therewith are commonly mounted rotatably around a pin 101a.

Numeral 109 represents a small month end feed lever and rotatably mounted as before by means of a stud pin 106b on the rear surface of the dial 106 and having a thickened pawl end 109a which is adapted for engagement with said date feed pawl 107. The feed lever 109 is formed at the opposite end by press job with a projection 10% which is adapted for engagement with a month discriminator lever 121 to be described, at the end of the month. A wire spring having its one end kept in fixed position by engagement with opening 106d and kept by its intermediate part in pressure engagement with pin 106a. The wire spring 120 has its opposite or free end kept in pressure engagement with the small month end feed lever 109 so that the latter is always urged resiliently to turn in counter clockwise direction in FIGS. 2 and 3 and finally and normally kept in pressure engagement with stud pin 106e.

Numeral 121 represents a month discriminator lever which is rotatably mounted on the plate 101 around a pin 101b studded thereon. One end 121a of this lever 121 is kept in pressure engagement with discriminator cam 103, while the opposite end 1211) of said lever 121 is ready for engagement with the projection 10% on lever 109 at the end of the month.

At the end of a small or even month, the lever end 121a is brought into engagement with one of high peripheral parts 103b of cam 103, as shown in full line in FIG. 2 and the other lever end 121b is brought into engagement with the projection 109b, so as to urge the lever 109 to turn in the clockwise direction and against the action of wire spring 120 until it is brought into and kept in pressure engagement with stop pin 106f. In this position, the pawl end 1090 of said feed lever 109 protrudes beyond an imaginary circle connecting the addendum ends of date dial teeth 106a towards the center of the watch movement, not shown, said center coinciding the rotational center of the date dial 106.

During the large or odd month, the lever end 121a is kept in engagement with one of the low peripheral parts 103a of month discriminator cam 103, while the opposite lever end 12,1b is thus unengageable with the projection 10% and the end pawl 109a of feed lever 109 does not protrude beyond said imaginary tooth end circle of date dial 106.

Numeral 122 represents a month feed lever which is formed at its central zone with an elongated slot 122a in which a studded pin 1010 on the plate 101 is slidably and pivotably received, said lever 122 being provided at its one end with a pawl 122b adapted for feed of the star wheel 102 when engaged therewith, and at its opposite end with a tail part 122c adapted for engagement with the pawl end 109a of small month end feed lever 109.

A wire spring 123 is fixedly mounted at its root end, not shown, on the plate 101, while the free end of said spring 123 is kept in pressure contact with a stop pin 122d mounted fixedly on month feed lever 122 which is thus resiliently urged to move leftwards and to swivel counter-clockwise in FIG. 2. In this way, the lever122 is normally kept in pressure contact with a stop pin 101d fixedly mounted on the plate 101, thereby its pawl end 12% being kept in separation from contact with month star wheel 102 as shown in FIG. 2.

A stationary guide pin l01e is studded on the plate in proximity to the lever 122, so as to guide the movement thereof by contact with the outer convexedly curved edge of said lever 122.

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

On any regular day of month except for the month end, the date calendar dial 106 is fed by a step corresponding to 24 hours per day under the action of date feed pawl 107, as in the similar way to the case of the first embodiment.

At the end of a small month, for instance April, the end 121a of month discriminator lever 121 is brought into engagement with one of the high peripheral parts 103b on the month discriminator cam 103. At this month end, and when the date dial 106 is rotated until the projection on small month end feed lever 109 is brought into engagement with the opposite end 121b of lever 121 and when the date symbol 30 appears through the date symbol display window, not shown, which can be made as at 10 in FIG. 1, the lever 109 is driven to swivel clockwise in FIG. 2 and the pawl end 109a will protrude as shown therein in full line. At the end of the 30th day, date feed pawl 107 will be brought into engagement with the thus protruded end pawl 109a and thus, the date dial 106 will be fed by 'a tooth pitch, so as to show the next calandar date symbol 3 1 through the display window. At this stage, the date dial 106 is headed from a slightly displaced position, as commonly known by the action of the related jumper spring, not shown. At the same time, the lever 109 is receded from contact with lever 121 and returns to the most counter-clockwise truned position as shown in chain-dotted line in FIG. 2. With further rotation of date feed pawl 107 in the direction shown by arrow E," it feeds the date dial as usual by a further tooth pitch, thus the following date display symbol l which represents the first date of the next following month, will become visible through the date display window.

During this transient period between the foregoing 31st calendar date and the now displaying 1st calendar date, the end pawl 109a of lever 109 will push the tail end 1220 of month feed lever 122 which is thus turned clockwise in FIG. 2 until it is brought into pressure contact with guide pin 101e and thus urged to slide rightwards in the same figure. By this movement, the lever end pawl 122b is brought into engagement with month star wheel 102 which is thus fed a step in the direction shown by the arrow F (refer to FIG. 3). In this way, the calendar display is converted into that of May the 1st. Almost concurrently, the engagement between pawl end 109a and tail end 122C is released, and month feed lever 122 will return to its position shown in Fib. 2 under the influence of spring force at 123. A reverse rotation of month star wheel 102 is positively prevented, upon returning with the sliding contact of lever 122 with the guide pin 101d.

During a large month, for instance May, the discriminator lever 121 is kept in engagement with one of low peripheral part 103a of said cam 103 and small month end feed lever 109 will maintain its most counter-clockwise turned position even at arrival of 30th day of the month, as shown in chain-dotted line in FIG. 2, thus the date calendar dial 106 will be fed as usually by a tooth pitch per day. At arrival of the 31st day of the month, month star wheel 102 will be fed a tooth as in the case of a small month as above referred to.

With separate provision of month discriminator 121 and month feed lever 122 as in the case of the present second embodiment, a certain design condition in the relative position between date calendar dial and month calendar dial can be substantially obviated, thus the design and structure of the related parts of the watch movement has a substantially broad freedom.

Further referring to FIG. 4, the third embodiment of the invention will be described in detail hereinbelow.

In the present embodiment, several main parts of the mechanism are shown by respective same reference numerals as in the first embodiment, yet adding each with 200. Thus, 201 represents the plate of the watch movement; 202 a month star wheel; 203 a month discriminator cam, said cam formed alternatively with low peripheral part 203a and high peripheral part 2013b. Month star wheel 202 and cam 203 are mutually fixed to each other, so as to provide in combination a month calendar dial 204 which is pivotably mounted on the plate 201 by means of a common stud 201a. Numeral 205 represents a month jumper spring as at 5 in the foregoing first embodiment; 206 a date calendar dial, having thirty one teeth 206a. The dial 206 comprises the thus formed gear portion 206b and represents thereon the corresponding 3 1 date calendar symbols on its plate portion 206c, although these date symbols have been omitted from the drawing for simplicity. A month feed pawl 206d adapted for engagement with said month star wheel 202 is fixedly and rigidly mounted on the dial 206.

A stud 201k is rigidly mounted on the plate 201 and serves for rotatable mounting of said dial 206. For provisional and resilient positioning of the dial 206, a jumper spring or lever 224, only partially shown, is fixedly mounted at its root end as usual on the plate 201.

Numeral 207 represents a date feed pawl corresponding to that shown at 7 in the first embodiment, said pawl 207 being fixedly mounted on a date feed wheel 208 formed and mounted in the similar way as at 8 in the first embodiment. This wheel 208 is rotatably mounted as before on the plate 201 by means of a stud 201C.

Numeral 209 represents a small month end feed member, preferably formed into a feed pawl as shown, as at 9 in the first embodiment, said feed pawl 209 is provided between the date symbol display part 206c and the gear part 206b and mounted on the latter.

The gear part 206b is provided thereon with three separate pins 206e, 206) and 206g.

The pawl 209 is formed with an elongated slot 209a and a peripheral recess 20% as shown for respective engagement with said pins 206e and 206f, thereby said pawl 209 being slidable in the radial direction relative to said gear part 206b. In addition, said pawl 209 is formed further with a pawl proper 209c kept in a constantly over-lapping way with a tooth 206a formed on said gear part 206b and corresponding to the 30th calendar daily display. A projection 209d is formed by pressing job on the pawl 209, said projection 209d being adapted for engagement with a month discriminator lever 221 to be described.

Numeral 220 represents a curved wire spring, one end of which is fixedly mounted by means of a pin 206g fixedly mounted on date dial 206, while its free end is kept in pressure engagement with said pawl 209, thus exerting a radially and outwardly directing resilient pressure relative to said gear part 206b upon said pawl 209.

From the foregoing, it will be seen that when the pawl proper 209a is brought into its outermost extrime of position by sliding movement of said pawl 209, the tip end of the pawl proper will protrude from an imaginary circle connecting tip ends of gear teeth 206b. The dial 206 comprises the thus formed gear portion 206b and represents thereon the corresponding thirty one dates calendar symbols on its plate portion 206e, although these date symbols have been omitted from the drawing for simplicity. A month feed pawl 206b adapted for engagement with said month star wheel 202 is fixedly and rigidly mounted on the dial 206.

Numeral 221 represents a month discriminator lever which is pivotably mounted on the plate 201 by means of a studded pin 201d. One end 221a of said lever 221 is kept in pressure engagement with discriminator cam 203 under the influence of spring 225 only partially shown, while the opposite end 221!) is adapted for engagement with a projection 209d on the feed pawl 209.

The operation of the third embodiment is as follows:

At any regular day except for month end, date feed pawl 207 will act as usual to feed the gear part 206b by one step per 24 hours in the direction of an arrow G.

During a small or even month, month discriminator lever 221 is kept in engagement with one of low peripheral parts 203a of cam 203, the lever 221 can not engage the projection 209d on feed pawl 209 even at the 30th day of the month.

The pawl 209 keeps its outermost peripheral position relative to the gear part 206b and its pawl proper 209c protrudes a small distance from the tip end of a specifically selected tooth on gear part 206b and corresponding to the 30th calendar date of the month. At the end of the 30th day, thus, date feed pawl 207 is brought into engagement with said pawl proper 209a so as to feed the date dial by two successive date steps for display of 1 corresponding the first date of the next following calendar month. By the shift of date display from 31 to 1, month feed pawl 206d will feed month star wheel 202 by a month step in the direction of arrow H," so as to display the next following month display.

During a large or odd month, discriminator lever 221 is kept in engagement with one of high peripheral parts 2031:. At the 30th day, small month end feed pawl 209 will receive pressure force through its projection 209d by engagement with lever end 221b, thus pawl proper 2090 being receded from its foregoing protruding position. For this reason, date feed pawl 207 is brought into engagement with a specific tooth 206a corresponding to the 30th date display symbol, so as to feed the gear part 206b by one tooth until the next following date display symbol or 31st calendar date will become visible through the related display window.

During display shift from 3l" to l," month star wheel 202 is fed just a tooth pitch, so as to display the next following calendar month.

Although not shown, a modification from the foregoing second and third embodiments may be such that the specific peripheral part on the discriminator cam 103 or 203, corresponding to calendar February, represents a higher peripheral part than those for other small or even months, so as to provide an automatic calendar date dial feed at the end of February of the year being of leap or of regular one. The month discriminator can be formed with a group of cam steps corresponding to four successive years in a proper way, as easily occur to any person skilled in the art from the foregoing description of the discriminator cam, for obviating manual calendar adjustments at all, otherwise to be carried out at every month end.

Finally, referring to FIGS. 5 and 6, the fourth embodiment of the invention will be described hereinbelow.

In the present embodiment, main working parts which are similar to those employed in the foregoing several embodiments Generally speaking, these parts are shown with respective same reference numerals, yet each being added with 300.

Thus, reference numeral 310 represents a conventional plate; and reference numeral 303 denotes a month discriminator cam concurrently serving as month star wheel denoted at 2; 102 and 202 in the foregoing. This cam 303 carries thereon twelve successive month display representations covering a year round, although not shown for simplicity. The cam 303 is formed on its periphery, twelve teeth 303a in radial registration of these month calendar displays. In this embodiment, the tooth bottoms are of different heights as at 30%; 3030 and 303d. The shallowest tooth bottoms 303b correspond to large or odd months, respectively. Middle height tooth bottoms 3030 correspond to small or even months, respectively. The sole deepest tooth bottom 303d corresponds to the regular Februa This cam 303 is united concentrically with a month display disc 304a, carrying successive twelve months of the year, so as to provide, in combination, a month calendar display dial at 304, although not specifically shown for simplicity.

The month dial, briefly, at 304 is rotatably and concentrically mounted on the conventional cannon wheel 350, as in the foregoing several embodiments.

Numeral 306 represents, only partially, a date calendar display dial as at 6 and 206 in the foregoing, and as shown in chain-dotted line in FIG. 5, said dial being rotatably mounted on as usual the plate 301. A jumper spring or lever, not shown, acts upon the dial 306 for keeping provisionally and resiliently in its position shown, for the prevention of unwillful rotation thereof.

As in the foregoing, the date dial 306 carries thereon 'thirty one successive date display symbols 1-31 covering a large or odd month, although not shown. This dial 306 is formedwith thirty one teeth 306a in radial registration of these date display symbols, respectively, although not shown for simplicity. A projection 3061) is formed on a specifically selected tooth as shown.

Date feed pawl 307 and a small month end feed wheel 307a constitute in combination a date feed member is fixedly mounted on the date feed wheel 308. Date feed wheel 308 is rotatably mounted on the plate 301 by means of a studded pin 301a, the rotational direction being shown by an arrow I. The feed wheel 308 performs a complete revolution per 24 hours as be fore.

Numeral 309 represents a small month end feed member, preferably formed into a lever as shown, which is pivotably mounted on date dial 306 by means of a studded pin 3060. This feed lever 309 is formed with a guide portion 309a; cam portion 30% and rack teeth portion 3090. Main month discriminator lever 321 and auxiliary month discriminator lever 324 are pivotably mounted on the plate 301 by means of respective stud pins 301!) and 3011:.

Main discriminator lever 321 has its one end 321a adapted for engagement any one of tooth bottoms 303b; 303c and 303d on the cam 303, while the opposite lever end 321b is adapted for engagement with one end 324a of auxiliary discriminator lever 324.

The auxiliary lever 324 is formed at its opposite end with a holder part 324b adapted for provisional holding of said cam portion 30% on lever 309 at the middle of each calendar month. On the holder part 324b, there are formed two projections 324b' and 32412" for determination of the relative position between the teeth portion 3090 and small month end feed wheel 307a.

One end 324a of said auxiliary lever 324 is kept in pressure contact with a wire spring 325, only partially shown, thereby the

levers

324 and 321 being urged resiliently to rotate clockwise and counterclockwise in FIG. 5, respectively. Therefore, it will be seen that the lever 321 may act as a jumper spring relative to the discriminator cam 303.

Month feed lever 322 is pivotably mounted on the plate 301 by means of a pivot pin 301d, the pawl end 322a of said lever 322 being positioned opposite the month discriminator cam 303 and the opposite lever end 322b being provided within the moving passage zone of the projection 306b on the date calendar dial 306. A partially shown wire spring 323 is kept in pressure contact with a pin 3220 on month feed lever 322, the latter being held at its regular or stationary position shown in FIG. 5.

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

At a large month such as May, date calendar dial 306 is fed daily only by the cooperation with date feed pawl 307 in the direction shown by an arrow J." Lever end 321a is in this case kept is engagement with one of shallow tooth bottoms 303b and thus, month discriminator main lever 321 and auxiliary lever 324 are kept in their respective most clockwise turned and most counterclockwise turned position shown. At 27th day or so, the guide portion 309a of small month end feed lever 309 which is mounted on date calendar dial 306 and brought to a proper position by rotation thereof, is brought to the position defined between two projections 324b' and 324b" for initiation of guided movement. Since the auxiliary lever 324 is positioned at its most counter-clockwise turned position, the toothed portion 3090 of said lever can not be brought into meshing relationship with the teeth of small monthend feed wheel 3070 during the period covering 27th 30th calendar day; and at 31st day, it will occupy the position shown in FIG. 6. In this way, date feed pawl 307 will feed the date calendar dial 306 just a tooth pitch at the end of 31st calendar day, and concurrently, the projection 306b on dial 306 will become engaged with the projection 322b of month feed lever 322, thereby the latter being turned clockwise and its pawl portion 322a acting upon the tooth 303a on cam 303 to feed it just a tooth pitch in the direction shown by an arrow I(." In this case, spring 323 will become effective to return month feed lever 322 back to its original position.

Thus, a new calendar display corresponding to the first day of June will visible through respective dateand month display windows.

At a small month, such as June, date calendar dial 306will be daily fed as usual during the period from the first to the 30th day of the month, by the action of date feed pawl 307. At the end of 30th day and upon daily feed of the dial 306 just a tooth pitch by the cooperating action of date feed pawl 307, the cam portion 30% of lever 309 will be caught between two projections 324b' and 32411" on auxiliary lever 324. During the small month, month discriminator lever 321 is kept in engagement with one of middle height tooth bottoms 3030, thus being positioned its more counter-clockwise turned position. The auxiliary lever 324 occupies in this case a clockwise turned position from that corresponding to the large or odd month.

Under these operational conditions, small month end feed lever 309 will occupy a counter-clockwise turned position from that corresponding to the large month shown in FIG. 6, wherein toothed portion 309c has been brought into engagement with the tooth of the feed wheel 3070 as shown in FIG. 5, thereby the date dial 306 being fed just a further tooth pitch. Concurrently, cam 303 is fed just a tooth pitch as in the case of a large month.

In this way, the next month and date calendar displays corresponding to the first date of June will become visible through respective display windows.

In the case of the regular February, the date dial 306 will be fed daily and regularly until arrival of the 28th calendar date.

In this case, month discriminator lever 321 is kept in engagement with the deepest tooth bottom on lever 303 and thus, it is positioned at a still further counterclockwise turned position from that shown in FIG. 5. At the end of the 28th day wherein the guide portion 309a of lever 309 is yet kept in engagement with two projections 324k and 324b", date feed pawl 307 feeds the date dial 306 just a tooth pitch and the toothed portion 309c initiates to engage the small month end feed wheel 3070. With further rotation of date feed wheel 308, said wheel 307a will act through said toothed portion 309c the'date dial 306 just three complete consecutive days, while, at the same time, the cam 303 is fed just a tooth pitch, for representing, in combination, the next following calendar display corresponding to the first date of March in the present preferred example.

In the present fourth embodiment so far shown and described, the month discriminator cam 303 may be, if necessary, divided into two elements as at 3; 103 and 203 and 2', 102 and 202 appearing in the foregoing first to third embodiment.

In the foregoing second to fourth embodiment, the month discriminator cam, month star wheel and the like constients constituting the month calendar dial may be designed so as to cover 48 consecutive months, when necessary, although not shown. In this case, the month discriminator cam may be formed with four different kinds of peripheral parts having mutually different heights, so as to correspond to large or odd months, small or even months, regular February and leap February, correspondingly. By adopting such modification as above, a complete automatic calendar feed at every month end can be assured in an easy way. In this respect, such modification can be applied in a more easy way to the fourth embodiment, since the latter utilizes related toothed members.

As an alternative measure, the month discriminator cam 103 or 203, as an example, as adopted in the foregoing second or third embodiment, respectively, may be modified in such'that the specific peripheral part corresponding to February has a still larger height than those of the peripheral parts corresponding to regular small or even months, in order to provide an automatic month end calendar feed at the regular or leap February, as may easily occur to any skilled person in the art upon review of the foregoing description of the invention.

In any of the foregoing several embodiments, month star wheel or month discriminator cam may carry every month calendar display symbol thereon Or alternatively, a separate month calendar display dial or the like member may be provided in cooperation with them.

In order to shorten the necessary time period for the month end calendar feed arrangement, a conventionally known quick acting feed means may be added to the date feed wheel and within the time range for feeding the date dial, in any of the foregoing embodiments.

In a further modification as may be applied to any of the foregoing first, second and third embodiments, the date feed pawl may be divided into two elements one of which does not engage the date dial in the regular days, yet capable of engaging the small month end feeder at every small month ends for feeding the date dial, while the other of which is adapted for performing the daily regular feed of the date dial once per complete day and in a quick-acting way, in order to shorten the calendar change operation periods.

The date feed pawl and the small month end feed wheel in the fourth embodiment may be, when necessary, mounted on respective separate pivot pins.

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

1. A calendar watch comprising a plate, a date calendar dial ring mounted on said plate and having thirty one successive date calendar display symbols and thirty one correspondingly arranged teeth, a month calendar dial ring rotatably mounted on said plate and comprising a month discriminator cam having at least twelve successive month calendar display symbols, said month calendar dial ring adapted to rotate a month step for a complete revolution of said date dial ring, said discriminator cam having different peripheral parts having different radial heights depending on the length of the calendar months, date feed means operatively connected with a conventional time-keeping and time indicating gear train engaging and advancing said date calendar dial a single tooth daily, a small month driver member pivotally mounted on said date dial and adapted to perform a complete revolution per month together therewith, and follower means operatively interposed between said driver and said cam for shifting said driver into operative engagement with said feed means at the end of the month for advancing said date calendar dial at least two teeth.

2. A calendar watch as set forth in claim 1 wherein said date feed means is comprises of a date feed pawl rotatable through a comple e revolution per day for feeding said date dial ring by a single tooth and a small month end feed wheel rotatable with said pawl, said small month drive member having tooth means thereon for engagement with said wheel.

3. A calendar watch as set forth in claim 1 further comprising a month feed member mounted on said plate and disposed for operative engagement with said date dial ring and said month dial ring for advancing said month dial ring and said discriminator cam upon rotation of said date dial ring at the end of a month.

Claims

2. A calendar watch as set forth in claim 1 wherein said date feed means is comprises of a date feed pawl rotatable through a complete revolution per day for feeding said date dial ring by a single tooth and a small month end feed wheel rotatable with said pawl, said small month drive member having tooth means thereon for engagement with said wheel.