The present invention relates to a radio controllable clock according to the preamble of claim 1.

Among conventional timepieces, there are radio controlled clocks capable of automatically adjusting the time after successfully receiving the radio time signal and decoding the signal to drive the hand shafts of an associated analog clock to an exact time position. Accompanying with the digital control to the analog rotation of the hand shafts to the exact time position matching with the digital output from the micro-controller, the second shaft, minute shaft, hour shaft and optionally the alarm shaft have to start at an absolute position whenever the system is reset, so that the micro-controller can calculate how many pulses must be generated for each shafts for a respective rotation.

Whereas most of said reset mechanism are relatively complicated in construction especially in case photoelectric barriers are used the respective rays of which have to pass through holes provided in respective gears of the hand shafts.

In addition, such mechanisms using photoelectric barriers are susceptible to malfunctions, so that in that cases it is impossible to reset the radio controlled clock.

For example, such photoelectric barriers are used according to FR-A-2639727. More precisely, light sources are used to transmit light rays that can pass orifices in gear wheels or can be reflected by reflection layers. According to the passage or blocked of light ray corresponding gear wheel position can be determined.

The EP 0 720 073 A2 shows a hand rotating mechanism for electronic watches in which the rearward movement of a gear wheel is prevented by rearward movement preventing means. If, at a certain position of a particular gear wheel, this gear wheel is blocked despite driving the gear wheel in a rearward direction, the gear wheel is assumed to be in a correct position. However, if, at this position, a rearward movement of the gear wheel is possible, this movement is detected by a further mechanism. Such detection corresponds to a wrong position of this particular gear wheel. Upon detection of a gear wheel being in a wrong position it can then be readjusted to its correct position. Overall, this procedure is comparatively complicated and requires the use of many elements and of motors that can drive the gear wheels in both directions, which requires precise bearings to avoid bearing play and respective tolerances of the respective hand position.

The EP 0 651 301 A2 describes an electronic watch, which facilitates the setting of the time. This document refers to enabling an user to set the time displayed by analogue hands by providing a corresponding input device.

The article "Junghans Funkuhr RC 2" by Wolfgang Ganter, published in Goldschmiede- und Uhrmacherzeitung, 1988, Vol. 1, page 148-149, discloses a radio controllable clock with two motors, one to drive minute and second hand, one to drive the hour hand. The position of the hands is detected by a light beam barrier and corresponding apertures in the gear wheels that drive the hands.

The EP 0 372 432 discloses another radio controllable clock. It comprises a movement preventing mechanism that implies stopping the drive itself of the hands.

Therefore, it is an objective of the present invention to provide a radio controllable clock as indicated above, which facilitates always a reliable setting of the time with simple technical means.

According to the present invention this objective is solved for radio controllable clock as indicated above by a means to mechanically stop the rotations of said hand shafts after respective predetermined rotations initiated by said micro-controller unit (9).

According to an advantageous embodiment of the present invention said hand shafts being rotatable by respective independent stepper motors, whereas these stepper motors are controllable by a micro-controller unit generating independently respective pulse signals.

According to a preferred embodiment of the present invention said means to mechanically stop the rotations of said hand shafts consisting of reset claw being adapted to abut respective protrusions associated to said hand shafts for second, minute and hour.

In addition, it is possible to provide an alarm hand shaft rotatable by a further stepper motor for resetting said alarm hand to the 12:00 o'clock position.

In order to ease the reset of the radio controlled clock, it is advantageous, when said micro-controller unit being adapted to control said stepper motors such said upon the receipt of a respective signal to reset that hand shafts to the 12:00 o'clock position the first stepper motor rotates the second hand shaft until an abutment, then the second stepper motor rotates the minute hand shaft until an abutment, and then the third stepper motor rotates the hour hand shaft until an abutment.

Of course it is possible that a fourth stepper motor rotates the alarm hand shaft until an abutment.

In order to reliably ensure a precise reset of the respective hands to the 12:00 o'clock position it is advantageous when said micro-controller unit generates pulses for one and a quarter rotation so that the second hand shaft being drivable by a second wheel and an axis rotor to make a respectively required rotation, whereas said second wheel is stoppable by said reset claw at the 12:00 o'clock position.

The same applies to the minute hand shaft which is drivable by a center wheel-shaft, a center wheel-idler, an intermediate wheel, a transmission wheel and a rotor to make a respectively required rotation.

In addition it is possible that said hour hand shaft being drivable by a center wheel-shaft, a center wheel-idler, an intermediate wheel, a transmission wheel and a rotor to make one and a respectively required rotation.

Of course this is also possible for said alarm hand shaft, which is drivable by a center wheel-shaft, a center wheel-idler, an intermediate wheel, a transmission wheel and a rotor to make one and a respectively required rotation.

Further, there may be provided a keypad for manually adjusting time and calendar, which may be indicated by an LCD-display.

Moreover, it may be possible to manually activate said means for mechanically stopping the hand shafts or said reset claw by a reset knob.

According to a preferred embodiment of the present invention upon generation of respective pulses by said micro-controller unit, the second shaft is driven by a second wheel and an achse rotor to make a respectively required rotation. The second wheel rotates until it is stopped by the reset claw. Then, it is defined as the 12:00 o'clock position of second. Secondly, the minute shaft is driven by a centre wheel-shaft, a centre wheel-idler, an intermediate wheel, a transmission wheel and a rotor to make a respectively required rotation. The minute shaft rotates until it is stopped by the reset claw. Then, it is defined as the 12:00 o'clock position of minute. The operations sequence of hour shaft and alarm shaft are similar as minute shaft. When all the 4 shafts rotations are completed, then, all of them are defined at the 12:00 o'clock position ready for adjusting after successful reception of radio time signal.

Further according to another embodiment of the present invention, when system is reset by switch on the reset knob, consequently, the reset claw is activated by the reset knob. Meanwhile, the MCU halts the whole system and is reset to 12:00 o'clock, LCD display is updated simultaneously. Then the MCU generates pulse signals to the four stepper motors to rotate the hand shafts respectively. First of all, the second shaft is driven by a second wheel and an achse rotor to make a respectively required rotation. The second wheel rotates until it is stopped by the reset claw. Then, it is defined as the 12:00 o'clock position of second. Secondly, the minute shaft is driven by a centre wheel-shaft, a centre wheel-idler, an intermediate wheel, a transmission wheel and a rotor to make a respecitvely required rotation. The minute shaft rotates until it is stopped by the reset claw. Then, it is defined as the 12:00 o'clock position of minute. The operations sequence of hour shaft and alarm shaft are similar as minute shaft. When all the four shafts' rotations are completed, then, all of them are defined at the 12:00 o'clock position ready for adjusting after successful reception of radio time signal.

According to another embodiment of the present invention, said radio controllable clock is adapted to be incorporated into a computer, e. g. personal computer, to ensure that said computers are providable with the exact time regardless of power supply malfunctions and the like.

Further, it is possible to remote control said radio controllable clock for ease of operating same.

Moreover, it is possible that said micro-controller unit functions as a master for said analog clock, which is the slave, without the need to receive radio signals for controlling same.

Further features and advantages will be apparent from the following description of several embodiments as well as the figures, in which,

• FIG. 1 is schematic diagram showing the circuit design of the radio controllable clock;
• FIG. 2 is plan view showing the essential part of Embodiment 1;
• FIG. 3 is isometric view showing the essential part of Embodiment 1;
• FIG. 4a is an exploded view showing essential part of Embodiment 1 of the self-position mechanism in accordance with present invention;
• FIG. 4b is a section showing essential part of Embodiment 1 of the self-position mechanism in accordance with present invention;
• FIG. 5 is plan view showing the essential part of Embodiment 2;
• FIG. 6 is isometric view showing the essential part of Embodiment 2;
• FIG. 7 is plan view showing the essential part of Embodiment 3;
• FIG. 8 is isometric view showing the essential part of Embodiment 3;
• FIG. 9 and 10 show how the reset claw included in Embodiment 3 stops the minute shaft from rotation. Similarly, the other shafts are also stopped by the reset claw with similar way.
• FIG. 11 is plan view showing the essential part of Embodiment 4;
• FIG. 12 is isometric view showing the essential part of Embodiment 4;
• FIG. 13 is plan view showing the essential part of Embodiment 5;
• FIG. 14 is isometric view showing the essential part of Embodiment 5.

While the present invention is practicable in various modes, an adequate number of embodiments thereof will be shown and described in detail.

Fig. 1 shows schematically a diagram illustrating the circuit design of the radio controllable clock.

As apparent from Fig. 1 the radio controllable clock 100 among others comprises a micro-controller unit 9 which receives various signals via an antenna 102 and a radio receiving means 104.

Said micro-controller unit 9 is connected to first through fourth stepper motors 5, 6, 7 and 8, which in turn are connected to a second shaft or second hand shaft 1, a minute shaft or a minute hand shaft 2, an hour shaft or hour hand shaft 3, and an alarm shaft or alarm hand shaft 4.

Upon respective signals generated by the micro-controller unit 9 the respective stepper motors 5, 6, 7 and 8 will be activated to rotate the respective shafts 1 to 4.

FIG. 2 is plan view showing the essential part of Embodiment 1, while FIG. 3 is an isometric view of the same. In these figures, the analog rotation of second shaft (1), minute shaft (2), hour shaft (3) and optionally alarm shaft (4) are driven by said four independent stepper motors (5), (6), (7) & (8), respectively, which are controlled by digital pulse signals generated from a micro-controller SKC-RDS01 (9), hereafter say MCU. Manual adjusting time and calendar is carried out by digital input via the rubber keypad (10). When time is adjusted manually in digital input on LCD display (11) or after successful reception of radio time signal, simultaneously, the MCU (9) generates pulse signals to the stepper motors (5), (6), (7) & (8) to drive the second shaft (1), minute shaft (2), hour shaft (3) and alarm shaft (4), respectively, to the corresponding position.

The MCU (9) generates pulses for one and a quarter rotation for each of said hand shafts (1), (2), (3) and (4) in order to ensure that all hand shafts (1), (2), (3) and (4) surely rotate to the 12:00 o'clock position. Of course, the respectively required rotation of said hand shafts (1), (2), (3) and (4) is less than one rotation.

FIG. 5 is plan view showing the essential part of Embodiment 2 while FIG. 6 is an isometric view of the same. The second shaft (1) is driven by a second wheel (14) and an achse rotor (15) to make the respectively required rotation. The second wheel (14) rotates until it is stopped by the reset claw (13). Then, it is defined as the 12:00 o'clock position of second.

FIG. 7 is plan view showing the essential part of Embodiment 3 while FIG. 8 is an isometric view of the same. The minute shaft (2) is driven by a centre wheel-shaft (16), a centre wheel-idler (17), an intermediate wheel (18), a transmission wheel (19) and a rotor (20) to make the respectively required rotation. The minute shaft (2) rotates until it is stopped by the reset claw (13). Then, it is defined as the 12:00 o'clock position of minute.

FIG. 9 and 10 are as same as FIG. 7 and 8, respectively, but showing in more detail the absolute position of the minute shaft (2) when it is defined as 12:00 o'clock position. The minute shaft (2) is driven by a centre wheel-shaft (16), a centre wheel-idler (17), an intermediate wheel (18), a transmission wheel (19) and a rotor (20) to make the respectively required rotation. During rotation, the rib on the minute shaft (2) touches the arm of the reset claw (13), therefore, the minute shaft (2) is stopped at that position. Then, it is defined as the 12:00 o'clock position of minute.

FIG. 11 is plan view showing the essential part of Embodiment 4 while FIG. 12 is an isometric view of the same. The hour shaft (3) is driven by a centre wheel-shaft (21), a centre wheel-idler (22), an intermediate wheel (23), a transmission wheel (24) and a rotor (25) to make the respectively required rotation. The hour shaft (3) rotates until it is stopped by the reset claw (13). Then, it is defined as the 12:00 o'clock position of hour.

FIG. 13 is plan view showing the essential part of Embodiment 5 while FIG. 14 is an isometric view of the same. The alarm shaft (4) is driven by a centre wheel-shaft (26), a centre wheel-idler (27), an intermediate wheel (28), a transmission wheel (29) and a rotor (30) to make a respectively required rotation. The alarm shaft (4) rotates until it is stopped by the reset claw (13). Then, it is defined as the 12:00 o'clock position of alarm.

Therefore, a timepiece is capable of automatically setting the second shaft (1), minute shaft (2), hour shaft (3) and alarm shaft (4), respectively, to an absolute position (12:00 o'clock), ready to receive the radio time signal. The analog rotation of second shaft (1), minute shaft (2), hour shaft (3) and alarm shaft (4) are driven by the independent stepper motors (5), (6), (7) and (8), respectively, which are controlled by digital pulse signals generated from a micro-controller SKC-RDS01 (9). Manual adjusting time and calendar is inputted by digital input via the rubber keypad (10). When time is adjusted manually in digital input on LCD display (11) or after successful reception of radio time signal, simultaneously, the MCU (9) generates pulse signals to the stepper motors (5), (6), (7) and (8) to drive the second shaft (1), minute shaft (2), hour shaft (3) and alarm shaft (4), respectively, to the corresponding position. Accompanying with the digital control to the analog rotation of hand shafts to the exact time position matching with the digital output from the micro-controller, the second shaft (1), minute shaft (2), hour shaft (3) and alarm shaft (4) have to start at an absolute position whenever system is reset. When system is reset by switch on the reset knob (12), consequently, the reset claw (13) is activated by the reset knob (12). Meanwhile, the MCU (9) halts the whole system and is reset to 12:00 o'clock, LCD display (11) is updated simultaneously. Then the MCU (9) generates pulse signals for one and a quarter rotation to the stepper motors (5), (6), (7) and (8) to rotate the hand shafts respectively, but less than one rotation. First of all, the second shaft (1) is driven by a second wheel (14) and an axis rotor (15) to make the respectively required rotation. The second wheel (14) rotates until it is stopped by the reset claw (13). Then, it is defined as the 12:00 o'clock position of second. Secondly, the minute shaft (2) is driven by a centre wheel-shaft (16), a centre wheel-idler (17), an intermediate wheel (18), a transmission wheel (19) and a rotor (20) to make the respectively required rotation. The minute shaft (2) rotates until it is stopped by the reset claw (13). Then, it is defined as the 12:00 o'clock position of minute. The operations sequence of hour shaft (3) and alarm shaft (4) are similar to the minute shaft (2). When all the 4 shafts' rotations are completed, then, all of them are defined at the 12:00 o'clock position ready for adjusting after successful reception of radio time signal.

Although not shown in the drawings, said radio controllable clock is capable to be remote controlled, preferably by radio signals, in order to ease the operation of same.

Moreover, said MCU (9) as a master is adapter to control said analog clock as a slave without receiving radio time signals. Therefore, said clock in addition is usable as a normal clock.

Further, said radio controllable clock is adapted to be incorporated into computers, e. g. personal computers, in order to always ensure that said computers are providable the exact time.

Although the present invention has been described and illustrated in detail, it should be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.