Calendar Clock

Abstract

A calendar clock comprising a conventional clockwork mechanism for indication of the time of day and a calendar mechanism coupled to the clockwork mechanism for being driven thereby by means of a 12-hour wheel which is seated on the hour-wheel shaft and which meshes in a ratio of 1:2 with a 24-hour wheel supported in the body of the calendar mechanism. The calendar mechanism is adapted to indicate the day of the week, the date, the month and moon phases, and it includes separate indicating devices therefor which are actuated by the clockwork mechanism. The day, date and month indicating devices are provided with respective dials each with indicia in the clockwise direction, and a respective hand. The hands are driven by means of ratchet wheels which derive their movement from the clockwork mechanism by means of pawls and an operating mechanism which follows curved cams and actuates the pawls.

Description

BACKGROUND

1. Field of the Invention

The invention relates to a calendar clock consisting of a conventional clockwork for indication of the time of the day and of a calendar mechanism which derives its movement from the clockwork by means of a 12-hour wheel which is seated on the hour-wheel shaft and which meshes in a ratio of 1:2 with a 24-hour wheel supported in the body of the calendar mechanism and wherein the calendar mechanism is adapted to indicate the day of the week, the month, the date and the moon phase.

2. Prior Art

In a conventional calendar clock of this kind, the names of the months are located on a manually adjustable disc, and they appear in a corresponding slot in the dial of the clock. The indicating devices for the date and for the day of the week are provided with a common indicator, and a geared wheel carrying a moon image turns every day at approximately 12.00 A. M. simultaneously with the above indicator by an angle corresponding to one day. The image of the moon cooperates with a suitably shaped slot or window in the dial of the clock, so that the phases of the moon are shown approximately correctly in the course of the month. Since the dates and the days of the week are arranged concentrically in two circles, one of them being located inside the other, the days of the week can only be represented by their first letters, and this results in difficult reading.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a clearer arrangement of the date, the day of the week, the month and the moon phase, wherein, in particular, even the indication of the month is to be accomplished automatically by the clockwork, and the indication of the continually changing moon phase is actually to be continuous and not step-wise once a day.

Additionally, the driving means and the control means of the calendar mechanism are to be simple and robust.

These objects are achieved according to the invention in that the calendar mechanism is provided with mutually separated indicating devices for the month, the day of the week, the date and the moon phase, which devices are actuated by the clockwork, the first three indicating devices each being provided with one dial, each of the dials being provided with indicia in the clock-wise direction, and with one indicator hand. The indicators are driven by means of ratchet wheels which derive their movement from the clockwork by means of pawls and operating means which follow curved cams and actuate the pawls.

By the separation of the individual indicating devices, a very clearly arranged and analogous indication of the various information can be achieved on a common dial with the very indication of the hour of the day, and the entire construction of the calendar mechanism according to the invention is simplified by the simple control by means of ratchet wheels, pawls and the curved cams and operating means associated therewith.

The uniform drive of the moon phase indicating device and the control of the remaining indicating devices can be achieved in accordance with an advantageous embodiment of the invention in such a manner that a moon drive and a first curved cam, i.e., a so-called day curved cam, are rigidly connected to the 24-hour wheel, wherein the moon drive meshes in an appropriate transmission ratio with a moon wheel which drives the moon phase indicating device, and a follower member follows the first curved cam, said follower member being seated on a connecting rod which is under the influence of a spring, the connecting rod carrying the pawls for driving the date ratchet wheel and day-of-the-week ratchet wheel. In this manner, a particularly simple and robust embodiment of the calendar clock according to the invention is obtained.

Preferably, the increasing portion of the first curved cam corresponds to the time period between approximately 4.00 A.M. to 12.00 A.M., and the decreasing portion corresponds to the time period between approximately 12.00 A.M. and 4.00 A.M. As a result of this, the changes of the date and of the day in the week occur in the time span during which the clock is mostly unobserved.

A step-wise switch, for instance, at 12.00 A.M., is conceivable in principle, resulting from a sudden drop on the curved cam. However, this possibility was intentionally omitted in order to prevent the curve on the curved cam from abutting against the connecting rod and possibly becoming stopped thereby when the indicators are manually turned in a counter-clockwise direction.

In an advantageous embodiment of the invention, the date ratchet wheel is provided with 31 teeth and the day-of-the-week ratchet wheel is provided with 21 teeth, the indicator of the date indicating device being directly attached to the date ratchet wheel and the indicator of the day-of-the-week indicating device being rigidly connected to a day-of-the-week gear wheel which meshes by means of an interposed gear wheel serving the purpose of reversing the direction of rotation of a gear wheel rigidly connected to the day-of-the-week ratchet wheel and having a 3:1 transmission ratio in relation to the day-of-the-week gear wheel. By this construction of the ratchet wheels and of the transmission and driving of the indicators, the switching distances for the date ratchet wheel and for the day-of-the-week ratchet wheel are approximately the same, and a common connecting rod or a similar device can be used for actuating the ratchet wheels.

In a simple embodiment of the invention, a second curved cam is rigidly connected to the date ratchet wheel, i.e., the so-called month curved cam, and a follower member on a pivotably supported connecting rod follows this curved cam, the end of the connecting rod which is opposite the pivot axis supporting the pawl for actuating the month ratchet wheel. The entire control of these three ratchet wheels, consequently, can be accomplished by means of two curved cams and two actuating members controlled by the cams and provided with one pawl for each ratchet wheel. This control is extremely simple and any degree of accuracy can be achieved by the same. Additionally, it adds only insignificant loading on the clockwork. The increase of the curvature of the second curved cam corresponds, to advantage, to a period of 31 days, wherein the decrease occurs suddenly within the period between 12.00 A.M. and 4.00 A.M. of the first day of a new month.

In this case, it is possible to resort to a sudden drop of the curvature, since the second curved cam can only rotate in one direction during the counter-clockwise rotation of the indicators as a result of the construction of the driving mechanism.

The month and date indicators can also be manually reset without any problems by a simple locking rotation of the same in the direction of the dial indicia.

According to another embodiment of the invention, the moon wheel carries a moon disc provided with two images of a full moon which are diametrically opposed, the moon disc being rotatable in relation to the moon wheel in order to enable manual setting and adjusting of the moon phase.

It has been discovered that it is particularly advantageous if the moon drive meshes with the moon wheel in a transmission ratio of 6:354, as the time of rotation of the moon disc in this case amounts to 29 days and 12 hours, which approximates the synodic orbiting time of 29 days, 12 hours, 44 minutes and 2.8 seconds.

The entire calendar mechanism according to the invention can be simply attached to a conventional clock, for instance a pendulum clock with a main spring drive or chain drive and Westminster chimes, so that it can be added to conventional standing timepieces or the like without substantial alterations of the clockwork.

An embodiment of the invention will next be explained in greater detail, with reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a front view of the dial of a calendar clock according to the invention,

FIG. 2 is a front view of the clock with the dial removed, and

FIG. 3 is a cross-sectional view taken approximately along the line III--III of FIG. 2.

DETAILED DESCRIPTION

Referring to FIG. 1, therein is seen a dial 10 provided with a shaped window 12 with two circular projections 14 extending into the window. A moon dial 18 is visible in the window, the moon dial being provided with two moon images 16 angularly offset at an angle of 180.degree.. Both circular projections 14 are constructed and positioned in such manner that the moon images 16 are covered by these projections in a certain position, namely in the new moon position. Consequently, during the rotation of the moon disc or dial 18 by 180.degree., one of the moon images 16 always travels from one new moon position behind one projection 14 to the next new moon position behind the other projection 14, whereas the other moon image is entirely covered.

Furthermore, the dial is provided with a conventional time scale 20, which cooperates with conventional hands 22. A date dial 24, a day-of-the-week dial 26 and a month dial 28 are arranged inside the scale 20, each of which cooperates with a respective indicator or hand 30, 32 and 34. All indicators, and also the moon disc 18, rotate in a clockwise direction. It can be seen in FIGS. 2 and 3 that the moon disc 18 carrying the moon image 16 is rotatably supported on a moon wheel 36 by means of a spring lock washer 38. The spring lock washer, the moon disc 18 and the moon wheel 36 are supported on a common axle 40, which is rigidly attached to the body 42 of the entire calendar mechanism.

The body 42 of the calendar mechanism is capable of being attached to the housing of a conventional clock 46 by means of plug connectors 44 and suitable fasteners (not shown).

The clockwork is provided in a conventional manner with a drive 48, an hour wheel 50, an hour wheel shaft 52, a minute shaft 54 as well as hands 22 moved by the minute shaft and hour wheel shaft respectively. The hands 22 cooperate with the time scale 20 on the dial 10 in the manner shown in FIG. 1.

An additional 12-hour wheel 56 is mounted on the hour wheel shaft 52, the 12-hour wheel meshing in a ratio of 1:2 with a 24-hour wheel 58 which is supported in the body 42 of the calendar mechanism, so that the wheel 58 undergoes one rotation a day in the counter-clockwise direction. A first curved cam 60, the so-called day curved cam, as well a moon drive 62 are rigidly connected to the 24-hour wheel 58. The moon drive 62 meshes with the moon wheel 36 in a transmission ratio of 6:354, so that the time of rotation of the moon disc 18 is 29 days 12 hours which approximates the synodic orbiting time of 29 days 12 hours 44 minutes and 2.8 seconds.

A roller 64 follows the day curved cam 60, said roller being supported on a connecting rod 66 which is provided with two longitudinal slots 68 and 70 which engage two bolts 72 and 74 rigidly connected to the body 42 of the calendar mechanism, so that the connecting rod is longitudinally displaceable in the calendar mechanism body. The connecting rod 66 is subject to the action of a spring 76 which acts to urge the roller 64 against the day curved cam 60.

The connecting rod 66 carries two pawls 78 and 80 which are held by means of a spring 82 attached to the connecting rod 66. Pawl 78 is in engagement with the teeth of a date ratchet wheel 84 with 31 teeth, the wheel 84 being supported in the body 42 of the calendar mechanism. The pawl 80 is in engagement with the teeth of a day-of-the-week ratchet wheel 86 with 21 teeth, the wheel 86 also being supported in the body 42 of the calendar mechanism. The day curved cam 60 has an increased radius in the period between approximately 4.00 A.M. and 12.00 A.M. and a decreased radius in the period between approximately 12.00 A.M. and 4.00 A.M., whereby both pawls shift by one tooth distance of both ratchet wheels 84 and 86 and both ratchet wheels are shifted by means of the pawls by one tooth distance during the passage of the decreased radius portion of the day curved cam 60. The indicator 30 of the date indicating device is fastened to the date ratchet wheel 84.

A gear wheel 88 is rigidly connected to the day-of-the-week ratchet wheel 86, the gear wheel 88 meshing in a ratio of 3:1 with an intermediate wheel 90 which serves to reverse the direction of movement. The intermediate gear wheel 90 meshes with a day-of-the-week gear wheel 92 in a transmission ratio of 1:1. The indicator 32 of the day-of-the-week indicating device is rigidly connected to the day-of-the-week gear wheel 92. Consequently, the indicator 32 is subject to exactly one revolution in the course of one week.

A second curved cam 94, the so-called month cam, is fastened to the date ratchet wheel 84. A member 96 follows the month curved cam 94, the member 96 being seated on a connecting rod 100 which is pivotably supported on an axle 98 attached to the body 42 of the calendar mechanism. The connecting rod 100 carries at its end opposite to the axle 98 a pawl 104 which is held in engagement, by means of a spring 102 attached to the connecting rod 100, with a month ratchet wheel 106 supported in the body 42 of the calendar mechanism. The indicator 34 of the month indicating device is rigidly connected to the month ratchet wheel 106. A spring 108 attached to the body 42 of the calendar mechanism urges the member 96 into contact with the month curved cam 94. The month curved cam is provided with an increasing portion extending through 31 days and an abrupt step-wise decreasing portion. The month ratchet wheel 106, consequently, is shifted on the 31st day of each month within a period of several hours in the night by one tooth. Locking springs 110,112 and 114 respectively prevent the three ratchet wheels 84, 86 and 106 from rotating in the opposite direction.

The invention has been described in connection with an automatic embodiment for the indication of day, date, month and moon phase, and as is well known each of the indicators or hands can be manually moved to adjust the associated reading as for example at the ends of months with less than 31 days.

Claims

What is claimed is:

1. A calendar clock comprising: a clockwork mechanism including an hour hand, a minute hand, an hour hand shaft supporting the hour hand and a minute hand shaft supporting the minute hand; a calendar mechanism for indicating day, date, month and moon phases; and means drivingly coupling the calendar mechanism and the clockwork mechanism, the latter means including a 24-hour wheel, a 12-hour wheel seated on the hour hand shaft and in mesh in a 1:2 ratio with the 24-hour wheel, said calendar mechanism including a day dial, a date dial, a month dial, the dials having indicia thereon arranged in the clockwise direction, a hand for each of the dials, a separate ratchet wheel coupled to each hand to drive the same with respect to its associated dial, a pawl coupled with each ratchet wheel to drive the same, cam means driven from said 24-hour wheel, and operating means coupled to said cam means for following the same and for operating said pawls to rotate the ratchets wheels and the hands therewith, the moon phase indicator being directly driven with the 24-hour wheel.

2. A calendar clock as claimed in claim 1 wherein said cam means comprises a first curved cam constituting a day cam rigidly connected to the 24-hour wheel, the means coupling the calendar mechanism and the clockwork mechanism comprising a drive for the moon phase indicator rigidly connected to the 24-hour wheel, and a moon wheel in mesh with said drive for the moon phase indicator, a follower member following the first curved cam, a connecting rod supporting said follower member, a spring acting on the connecting rod to urge the follower member against said first cam, said pawls for driving the date ratchet wheel and the day ratchet wheel being mounted on said connecting rod.

3. A calendar clock as claimed in claim 2 wherein said first cam includes a portion of increasing radius which approximately corresponds to the time period between 4.00 A.M. and 12.00 A.M., and a portion of decreasing radius which approximately corresponds to the time period between 12.00 A.M. and 4.00 A.M.

4. A calendar clock as claimed in claim 2 wherein the date ratchet wheel is provided with 31 teeth and the day ratchet wheel is provided with 21 teeth, the arm of the date indicator being directly attached to the date ratchet wheel.

5. A calendar clock as claimed in claim 4 comprising a day gear wheel rigidly supporting the day hand, an intermediate gear in mesh with the day gear wheel, and a gear wheel rigidly connected with the day ratchet wheel and in mesh with said intermediate gear, the intermediate gear providing reverse direction of rotation of the day gear wheel relative to the day ratchet gear and a transmission ratio of 1:3.

6. A calendar clock as claimed in claim 3 wherein said cam means further comprises a second curved cam rigidly connected to the date ratchet wheel and constituting a month curved cam, a second follower member for said second cam of a pivotably supported second connecting rod supporting said second follower member, a spring acting on the second rod to urge the second follower member against the second cam, the second connecting rod having an end remote from its pivot axis which supports the pawl for actuating the month ratchet wheel.

7. A calendar clock as claimed in claim 6 wherein said second cam includes a portion of increasing radius which corresponds to a time period of 31 days.

8. A calendar clock as claimed in claim 2 wherein said moon phase indicator further comprises a moon disc carried by said moon wheel and including two portions constituted as images of the moon which are angularly offset by an angle of 180.degree., the moon disc being rotatable with respect to the moon wheel.

9. A calendar clock as claimed in claim 2 wherein the drive for the moon phase indicator is in mesh with the moon wheel in a transmission ratio of 6:354.

10. A calendar clock as claimed in claim 1 wherein said calendar mechanism comprises a body which is fixable to said clockwork mechanism.