Abstract:
A dating mechanism for calendar clocks wherein, in order to simplify a motion transmitting mechanism for intermittently rotating a date indicating drum or a week day indicating drum by the rotation of an hour indicating drum, the hour and minute indicating drums arranged adjacently on the same axis and the date and week day indicating drums arranged adjacently on the other same axis are arranged parallelly above and below and an intermittently feeding lever for transmitting the rotation of the hour indicating drum to the date indicating drum is provided between the hour indicating drum and date indicating drum.

Description:
BACKGROUND OF THE INVENTION 
     (a) Field of the Invention: 
     The present invention relates to dating mechanisms for calendar clocks and more particularly to date and week day indicating mechanisms for digital calendar clocks. 
     (B) Description of the Prior Art: 
     In a known conventional digital calendar clock, it is general that respective date, week day, hour and minute indicating drums are arranged on the same axis. However, in the case of such arrangement, there have been defects that a speed reduction mechanism for transmitting a motion from the hour indicating drum to the date or week day indicating drum is likely to become complicated and that therefore the efficiency of the assembling operation is low. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide a dating mechanism for calendar clocks wherein hour and minute indicating drums arranged adjacently on the same axis and date and week day indicating drums arranged adjacently on the outer same axis are arranged parallely above and below so that such defects as are mentioned above may be eliminated. 
     Another object of the present invention is to provide a digital calendar clock formed to be very compact as a whole and positive in the operation. 
     A further object of the present invention is to provide a dating mechanism for calendar clocks which is simple in the assembling operation. 
     These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevation of an essential part of an embodiment of a digital calendar clock according to the present invention; 
     FIG. 2 is a sectioned view on line II--II in FIG. 1 shown by removing a body frame; 
     FIG. 3 is a partial elevation showing an essential part of another embodiment of a digital calendar clock according to the present invention; and 
     FIG. 4 is the same sectioned view as FIG. 2 on line IV--IV in FIG. 3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 and 2, numeral 1 signifies a body frame, numeral 2 signifies a driving motor fitted to the body frame 1 and having a pinion 2a at the tip of an output shaft, numeral 3 signifies a rotary shaft rotatably borne on the body frame 1, numeral 4 signifies a gear secured to the rotary shaft 3 and meshed with the pinion 2a, numeral 5 signifies a minute indicating drum secured to the rotary shaft 3, numeral 6 signifies one of many minute indicating leaves pivotably supported on the minute indicating drum, numeral 7 signifies a holding piece secured to the body frame 1 and for holding the minute indicating leaves 6 in a vertical position, numeral 8 signifies an hour indicating drum mounted rotatably on the rotary shaft 3 and having a projection 8a on one side surface, numeral 9 signifies one of many hour indicating leaves pivotably supported on the hour indicating drum 8 and numeral 10 signifies a holding piece secured to the body frame 1 and for holding the hour indicating leaves 9 in a vertical position. The hour indicating drum 8 is connected with the minute indicating drum 5, that is, the rotary shaft 3 through a well known speed reduction gear so as to make one or two rotations during 24 hours and to be able to indicate the time through the leaves 6 and 9 together with the minute indicating drum 5. 
     Numeral 11 signifies a supporting shaft fitted to the body frame 1 parallelly with the rotary shaft 3. Numeral 12 signifies a date indicating drum mounted rotatably on the supporting shaft 11 and having a ratchet wheel 12b in a position adjacent to one side wall of the body frame 1 through a tubular shaft 12a rotatably fitted to the supporting shaft 11. Numeral 13 signifies one of many date indicating leaves pivotably supported on the date indicating drum 12. Numeral 14 signifies a holding piece secured to the body frame 1 and for holding the date indicating leaves 13 in a vertical position. Numeral 15 signifies a week day indicating drum mounted rotatably on the tubular shaft 12a and having a ratchet wheel 15a opposed to the above mentioned ratchet wheel 12b on one side surface. Numeral 16 signifies one of many week day indicating leaves pivotably supported on the week day indicating drum 15. Numeral 17 signifies a holding piece secured to the body frame 1 and for holding the week day indicating leaves 16 in a vertical position. 
     Numeral 18 signifies a feeding lever supported rotatably on the tubular shaft 12a, extending at one arm end to a position in which it can engage with the projection 8a of the hour indicating drum 8 and forming at the other arm end a ratchet 18a which can engage with the ratchet wheel 12b of the date indicating drum 12 and the ratchet wheel 15a of the week day indicating drum 15. Numeral 19 signifies a spring clockwise biasing the feeding lever 18 in the position in FIG. 2. Numeral 20 signifies a plate spring secured in the base portion to the body frame 1 and engaged in the tip portion with the ratchet wheels 12b and 15a to prevent the reverse rotation of the date indicating drum 12 and week day indicating drum 15 and to regulate their rotating positions. 
     The operation of this mechanism shall be explained in the following by exemplifying the case of rotating the week day indicating drum 15 with the rotation of the hour indicating drum 8 by particularly referring to FIG. 2. 
     When the driving motor 2 rotates, the hour indicating drum 8 will be rotated in the direction indicated by the arrow in FIG. 2. But, at a predetermined time, the projection 8a will contact the feeding lever 18 and will push it to counterclockwise rotate the feeding lever 18 against the spring 19. With this counterclockwise rotation of the feeding lever 18, the ratchet 18a will move in the counterclockwise direction around the tubular shaft 12a and will engage with the bottom of a tooth preceding by one tooth in the counterclockwise direction in FIG. 2 by overpassing the tooth tip of the ratchet wheel 15a while flexing due to its own resiliency. In this case, due to the frictional force between the ratchet 18a and ratchet wheel 15a, the ratchet wheel 15a will tend to be rotated counterclockwise in FIG. 2. But this tendency will be prevented by the plate spring 20. Thus, when the time indicated by the indicating leaves 9 and 6 approaches 12:00 P.M. (0:00 A.M.), the projection 8a of the hour indicating drum 8 will move to the chain line position in FIG. 2 but, the moment when the indicated time becomes 12:00 P.M., the feeding lever 18 will disengage from the projection 8a and will be quickly rotated clockwise in FIG. 2 by the spring 19. By this clockwise rotation of the feeding lever 18, the ratchet wheel 15a, that is, the week day indicating drum 15 will be rotated clockwise by one tooth of the ratchet wheel 15a and the next week day will be indicated through the week day indicating leaf 16. Thereafter, while repeating such operation as is mentioned above at intervals of 24 hours or of 12 hours (in case two leaves indicating the same week day are provided), new week days will be indicated in turn. 
     The case that the week day indicating drum 15 is rotated by the rotation of the hour indicating drum 8 has been explained in the above. The ratchet 18a of the feeding lever 18 will act the same also on the ratchet 12b of the date indicating drum 12 to rotate the date indicating drum 12 intermittently in turn to indicate dates. However, in such case, as the ratchet wheels 15a and 12b are different from each other in the number of teeth (for example, it is usual that the ratchet wheel 15a has 7× 4= 28 teeth and the ratchet wheel 12b has 31 teeth), in case, for example, the ratchet wheels 15a and 12b are made to be of the same diameter, the ratchet wheel 15a will become larger than the ratchet wheel 12b in the pitch of the teeth. Therefore, as a result, the ratchet 18a of the feeding lever 18 will overpass the tooth tip of the ratchet wheel 12b, will then slightly move, will overpass the tooth tip of the ratchet wheel 15a and will engage with the tooth bottoms of both ratchet wheels 12b and 15a. When the projection 8a of the hour indicating drum 8 disengages from the feeding lever 18, the ratchet 18a will first push the ratchet wheel 15a and will then push the ratchet wheel 12b to rotate both ratchet wheels 12b and 15a. 
     In the above explained embodiment, the operating member provided in the hour indicating drum 8 is formed as an arcuate projection 8a and the feeding lever 18 is rotatably supported on the tubular shaft 12a but these can be altered as shown in FIGS. 3 and 4. 
     That is to say, in the embodiment shown in FIGS. 3 and 4, the operating member 8a provided on the hour indicating drum 8 is formed as a cam projecting on the side surface of the drum 8, the feeding lever 18 is rotatably supported on the body frame 1 and the ratchet 18a is formed as another member rotatably fitted on the feeding lever 18. The ratchet member 18a is biased counterclockwise in the position in FIG. 4 by a spring 18b and the feeding lever 18 is pressed against the peripheral side surface of the cam 8a by the spring 19 through a pin 18c. 
     By the way, the operation of this embodiment is the same as is explained with reference to FIGS. 1 and 2 and therefore shall not be explained in detail. 
     In the above explained embodiment, at least the ratchet portion 18a of the feeding lever 18 is formed preferably of a spring material and the date indicating drum 12 and week day indicating drum 15 may be arranged as interchanged with each other in the position.