Display Device for Calendar Timepieces

The present invention relates to a display device for calendar timepieces and more particularly to a month displaying device.

There has been provided a calendar watch having an automatic correcting device for the varying the lengths of a month. In the calendar watch, the date dial is driven two steps on the night of the 30th day of an even month to bring the date indication "1" into the date window at the beginning of the next month. Accordingly, date display is automatically corrected according to the length of month.

In such a calendar watch, it is preferable to provide a month display to display the month which has been set in the watch to the user, and which is useful to correct the date. However, since the space for the calendar display window is limited, it is too small to indicate visibly the month together with the date and day in one window. In order to correct the date, it is necessary to know the change of the month during the correcting operation.

It is an object of the present invention to provide a calendar display device which indicates the month together with the date indication "1" to indicate the change of month.

In accordance with the present invention, the calendar display device comprises calendar indicating dials including a date dial adapted to be rotated one step every 24 hours and a month dial adapted to be rotated one step during the rotation of said date dial between the date indications "31" and "1", a window for displaying indications on said date dial and month dial, and means for disclosing the month indication in said window at a predetermined time.

These and other objects and features of the present invention will become fully apparent from the following detailed description in conjunction with the accompanying drawings.

FIG. 1 is a plan view of a calendar display device of the prior art,

FIG. 2 is a sectional view of the device of FIG. 1,

FIG. 3 is a plan view of an embodiment of the present invention,

FIG. 4 is a sectional view of the device of FIG. 3,

FIG. 5 is a plan view of another embodiment,

FIG. 6 is a sectional view of the device of FIG. 5,

FIG. 7 is a plan view showing a further embodiment,

FIG. 8 is a plan view of still another embodiment,

FIG. 9 is a sectional view of the device of FIG. 8,

FIG. 10 is a plan view showing an another embodiment,

FIGS. 11 to 14 are plan views and sectional views showing other embodiments, and

FIG. 15 is a plan view of a still another embodiment.

Referring to the drawings and more particularly to FIGS. 1 and 2 showing the prior art, an annular date dial 2 having a toothing 2a is rotatably supported on a base plate 1 and driven one step every 24 hours by a finger (not shown) engaged with the toothing 2a. A month dial 5 is rotatably mounted on the base plate 1 and positioned by a jumper spring 3. The month dial 5 is driven one step by engagement of a pin 2b of the date dial 2 with a toothing 5a during the rotation of the date dial between the indications "31" and "1". A week day dial 7 is secured to a star wheel 7a positioned by a jumper spring 8 and is driven by a not shown finger. Indications of day, date and month are displayed through a window 9a of a watch dial 9. Since the window is limited in size and divided into three displaying sections, each section must be reduced to small size. Therefore, it is difficult to see the indication on each dial. The present invention is to remove such a drawback.

Referring to FIGS. 3 and 4, an annular date dial 12 has an opening 12a as a window which is positioned at the date indication "1". Each of date indications other than "1" are printed within the space of about half of the window 9a. A month dial 15 is positioned under the date dial 12 and rotatably mounted on the base plate 1. The month dial 15 has a toothing 15a which is engaged with a pin 12b provided on the underside of the date dial 12. As mentioned above, the month dial 15 is driven one step by the pin 12b during the rotation of the date dial between the indications "31" and "1". In the window 9a of the watch dial 9, indications of the date dial 12 and the week day dial 7 are displayed. In this embodiment, date indication "1" is printed on the month dial 15 together with the month indication.

In operation, at the beginning of the month, the opening 12a of the date dial 12 is positioned in the window 9a, so that the month indication and date indication "1" may be observed. At midnight of the 1st day, the date dial is driven one step so that date indication "2" is brought in the window. The month dial 15 is covered by the date dial. Until indication "31", only the date indication is displayed in the window. However, it is also possible to indicate the change of the month during the date correcting operation at the beginning of month.

Referring to FIGS. 5 to 7, a month dial 25 has a toothing 25a and a series of month indicating projections 25b, each of which is inwardly projected over the date dial 22. The projections are arranged at a pitch of double the toothing 25a. On each projection, month indication and date indication "1" are printed. The toothing 25a is engaged with a month dial driving wheel 24 rotatably supported on the base plate 1. On the underside of the date dial 22, two pins 22c and 22d are provided, of which pin 22c is so disposed as to engage with the month dial driving wheel 24 during the rotation between the date indications "31" and "1" and the pin 22d is so arranged as to engage with the wheel between the date indications "1" and "2".

In operation, at midnight of 31st day of the month, dial 25 is driven one step by rotation of the wheel 24 caused by the engagement of the pin 22c, so that the month indication is displayed in the window 9a together with the date indication "1" as shown in FIG. 5. During the rotation between the indications "1" and "2", the month dial is driven once more by engagement of the pin 22d, whereby the projection 25b is removed to the underside of the watch dial 9 and the date indication "2" is displayed in the window 9a as shown in FIG. 7. During the operation between the date indications "2" and "31", the month dial remains in position behind the watch dial.

Referring to FIGS. 8 and 9, a date dial 26 has an opening 26a at the outside of the indication "1". A month dial 27 is positioned under the date dial and each of the month indications is positioned to appear in the opening 26a. The month dial has a toothing 28 which is engaged with a driving wheel 29. The driving wheel is driven one step by a pin 30 provided on the date dial between the date indications "31" and "1" thereby rotating the month dial. Thus, the next month indication and the date indication "1" are brought in the window 9a as shown in FIG. 8, whereby the month indication may be observed through the window and opening. In the day other than 1st day, only date indication is displayed in the window. Since the letter "1" is simple and has a narrower width, the letter of each month indication may be printed in large size. Thus, the indications of the date and month may be easily observed.

FIG. 10 shows another embodiment, there is illustrated a date dial 31 and a month dial 32, other parts are the same as the device of FIGS. 8 and 9. An opening 31a is positioned between the indications "31" and "1". Therefore, the month indication is displayed in the period in which the date indication changes from "31" to "1". In accordance with this embodiment, although the month displaying period is short, it is possible to indicate a charge in the month during the date correcting operation.

Referring to FIGS. 11 and 12, construction of this embodiment is similar to the first embodiment of FIGS. 3 and 4. Therefore, the same parts are identified with the same numbers as those of the previous embodiment of FIGS. 3 and 4. The date dial 12 has an opening 12c at the inside of the date indication "1" and the month indication on the month dial 15 is positioned to correspond to the opening 12c. Thus, the month indication is displayed in the window 9a together with the date indication "1".

The device of FIGS. 13 and 14 is similar to that of FIGS. 5 to 7 and same numerals are used for identifying the same parts. On each projection 25b, the month indication is printed, so that it may be brought in the window only at the beginning of the month.

Referring to FIG. 15, the week day dial 33 has openings 34 at every space between the day indications, the month dial 35 is positioned under the week day dial to correspond to the opening. Therefore, the month indication is displayed in the window at the time when the day indication is changed.

It will be understood that month indication may be displayed at a time other than the 1st day, for example at the time of a single date indication such as 2nd to 9th day.