GB2212632A - Timepiece movement - Google Patents

Abstract

The present invention provides a clock movement for table or wall clocks, the movement including a synchronous motor section and analog display section, the synchronous motor section being adapted to receive a fixed cycle pulse a signal to rotate analog indicating hands at a fixed speed. The synchronous motor section includes an elongate C-shaped stator 14 disposed within a case 10, 12 and a rotor 24 rotatably supported by the case and rotated between stator poles 14c, 14d of the stator, the rotor having a rotor pinion 20 engaged by a first reduction wheel 32, the rotation of the first reduction wheel being transmitted to the analog 46, 64 indicating hands through a time-indicating gear train 38, 40, 42, both the first reduction wheel and time indicating-gear train being disposed within the case. The gear train from the rotor to the time-indicating hands is disposed on a straight or curved line extending from the central stator axis to provide an elongate configuration to the movement case. <IMAGE>

Description

TIMEPIECE MOVEMENT DESCRIPTION The present invention relates to timepiece mov-ements, particularly but not exclusively small sized movements driven by synchronous motors and suitable for clocks such as wall clocks, table clocks and the like.

Most table clocks and wall clocks have heretofore been crystal clocks utilizing a crystal oscillatcr which provides a high accuracy oscillation. Such a crystal oscillator serves as a time reference source of oscillation to secure very good accuracy of time indication.

In such crystal clocks, the movement includes a main mechanism for rotatably driving time indicating hands by the use of electrical clock pulses. Such a mechanism is generally divided into a synchronous motor section and a gear train section.

The synchronous motor section includes a stator coil to which high accuracy clock pulses obtained by dividing the frequency of crystal oscillation are applied, a stator having stator poles which can be placed under the action of the magnetic flux in the stator coil, and a rotor rotatable between the stator poles. On the other hand, the gear train section functions to reduce the velocity of the rotating rotor gradually and to transit the rotation of the rotor to the clock hands.

The external form of conventional clock movements is normally of substantially circular or square shape, so that as many of the parts of the movement as possible can be located about the hour hand of a clock.

If a clock movement has a synchronous motor and a clock gear train arranged about the hour hand, the clock movement can be used for either a wall or a table clock. When one or more external parts such as a dial plate, indicating hands and decorative case are changed for other parts of a single type of clock, the latter can be converted into another type of clock.

Since the conventional movements have parts arranged about the hour hand as described, the movements are necessarily increased in thickness. If the gear train includes two or three wheel layers, this makes the assembly of the clock difficult in addition to the increased thickness of the movement.

The conventional movements have a further problem in that they cannot deal sufficiently well with particular designs of clock. Such designs include, for example, clocks having a concealed movements. Such clocks have a mechanism for driving time indicator hands which mechanism cannot easily be seen. This provides a unique design for the clock. Probably, such a unique design will make a new genre for clock design.

However, it is extremely difficult to conceal completely all the parts arranged about the hour hand of the clock.

There has been proposed a skeleton clock which is intended to conceal as much of its movement as possible. However, this also could not provide a movement which was satisfactorily concealed.

There has also been a proposal to provide a small sized movement suitable for use in a concealed-movement type of clock. In such a case, the small-sized movement must provide a satisfactorily large driving torque. The concealed movement type clock requires time indicator hands which are sufficiently large in comparison with the small size of the movement. This intends to give an impression to a user in that such large and long hands cannot be driven only by a mechanism assembled into any one strut or column of the clock. Such an impression will make the user recognize a new design of clock.

On the other hand, however, the synchronous motor must provide an increased torque for driving the large and long hands in the small-sized movement of the clock. In the prior art, such an increased torque was accomplished by increasing the magnetic flux in the rotor. The increase of the torque causes a magnetic connection between the rotor and any metallic part located near the rotor. Particularly when the smallsized movement has a battery as a source of current supply arranged near the rotor, the latter is magnetically attracted toward the battery to create an unnecessary inclination in the rotor which will cause various malfunctions.

With the small-sized clock movement suitable for use in concealed-movement type clocks and capable of driying the large and long hands, therefore, the positional relationship between the rotor and the battery is a very important factor.

Further, the clock movement may include an analog display section to be driven by the synchronous motor.

The synchronous motor receives- a given drive signal (normally, a fixed cycle pulse signal) from a drive section. The drive section includes a motor drive circuit and a battery.

The analogue display section is assembled with the drive section to form a unitary clock movement.

However, such a unitary clock movement tends to increase the whole size of the movement and is particularly disadvantageous for the concealed-movement type clocks as aforementioned.

It is therefore an object of the present invention to provide a new and inconspicuous clock movement suitable for use in concealed-movement type clocks, which is of a small size and provides a satisfactorilyhigh driving force.

To this end, the present invention provides a new clock movement having an overall elongate configuration and comprising a synchronous motor section and a clock gear train section, these sections being basically arranged in a line, the movement further comprising time-indicator hands capable of being disposed at or near the distal end of the movement.

Thus, the clock movement still further comprises a stator of longitudinally extending C-shaped configuration, the stator having a pair of parallel legs, one of which includes a stator coil wound therearound. The stator also includes a central axis extending between the legs, a rotor located on the central axis and a first reduction wheel (or fifth wheel) similarly located on the central axis. Such an arrangement can allow the movement to be small in size and capable of providing a sufficient driving force.

In addition to the rotor and first reduction wheel, the clock movement can include a time-indicating gear train arranged in a straight line along the central stator axis or in a curved line contacting the central stator axis. This can provide a small-sized movement of an elongate configuration which extends from the stator to the gear train.

In embodiments of the present invention, therefore, the elongate movement can be completely concealed within a hollow strut which supports the time-indicator hands, in contrast with the conventional movements of circular or square configuration in which the parts are collected and mounted about the time indication shaft. Since the movement of the present invention can be of small size, but yet provide a relatively high drive force, the time indicator shaft on which hands, which can be long and large, are mounted cannot externally be viewed to have its driving mechanism located within the shaft itself. Thus, there can be provided a unique design of an appearance as if its time indicator hands were rotated without any drive mechanism.

The present invention can thus provide an unexpectedly increased degree of freedom of design.

The present invention can also provide an elongate clock movement comprising a synchronous motor arranged in a line relative to a time-indicating gear train and time-indicating hands mounted on the distal end of the movement, thereby providing a sufficiently large space formed about the time indicating shaft.

The present invention can therefore provide an elongate clock movement with a said space extending through a large angle, for example, 200 degrees about the time-indicating shaft. If such a spatial region is covered by a transparent dial plate or the like, the time-indicating shaft on which the long indicator hands are mounted cannot externally be seen to have a drive mechanism. This thus provides a unique design, appearing as if the indicating hands rotate without any drive mechanism.

The present invention can further provide an elongate and thin movement comprising a movement case divided into upper and lower elongate case sections, a stator disposed between the upper and lower case sections, a rotor driven by the stator, a first reduction wheel operatively engaged by the rotor and a time-indicating gear train for rotatably driving time indicator hands, the whole gear train being supported between the upper and lower case sections in a line and located within the height of the rotor.

In accordance with the present invention, further, the movement can easily be subjected to automatic assembly since the stator, rotor and gear train are arranged in a line and completely disposed between the upper and lower case sections.

The present invention can further provide a clock movement comprising a synchronous motor section, a clock gear train section basically arranged relative to the synchronous motor section in a line, time indicator hands adapted to be mounted on the movement at or near the distal end thereof, and battery means arranged on the opposite side of the stator relative to the wheel train.

The clock movement may also comprise a stator of longitudinally extending C-shaped configuration and having a pair of parallel legs1 a stator coil wound about one of the stator legs, a central stator axis extending between the parallel legs, a rotor disposed on the central stator axis, and a first reduction wheel located on the central stator axis. Thus, the clock movement can be small-sized and yet provide a sufficiently large drive power.

The time gear train section may include a timeindicating gear train arranged in a straight line extending along the central stator axis or a curved line contacting the central stator axis. The battery may be disposed on the opposite side of the elongated stator relative to the gear train.

In movements embodying the present invention, therefore, the elongate movement can be completely concealed within a hollow strut for supporting the time indicator hands, in contrast with the conventional movements of circular or square configuration in which the parts are collected and mounted about the time indication shaft. Since the movement of the present invention can be of a small size, but yet can provide a high drive force, the time indicator shaft on which hands which may be long and large are mounted cannot be seen to have its driving mechanism located within the shaft itself. Thus, there can be provided a unique design, appearing as if its time indicator hands are rotated without any drive mechanism.

When the battery is arranged on the opposite side of the stator relative to the gear train, a rotor producing a strong magnetic force is further separated from the battery through the elongate stator even in a small-sized clock movement, so that the aforementioned inclination can positively be prevented in the rotor.

The present invention can further provide a clock movement comprising an analog display section and a drive section which are separated from each other, the analog display section being as reduced in size as possible and adapted to drive time indicator hands, the drive section including a battery and a motor drive circuit and electrically connected with the analog display section through a flexible wiring section such as lead wires or a flexible printed substrate. As a result, the drive and analog display sections may individually be mounted, for example, within separate clock struts. Thus, the analog display section for driving the time indicating hands can be very small in size.

In accordance with the present invention, therefore, the analog display section can be effectively separated from the drive section such that the respective sections can be mounted separately within two different parts of the clock. The analog display and drive sections are electrically connected with each other through the flexible wiring section.

As a result, the clock can highly be reduced in size.

In the analog display section of the present invention, the elongated movement can be completely concealed within a hollow strut for supporting the time indicator hands, in contrast to the conventional movements of circular or square configuration in which the parts are collected and mounted about the time indication shaft.

Since the movement of the present invention is of small size, but yet can provide a high drive force, the time indicator shaft, on which what may be long and large hands are mountec, cannot externally be seen to have its driving mechanism located within the shaft itself.

Thus, there can be provided a unique design appearing as if its time indicator hands are rotated without any drive mechanism.

The present invention can further provide a clock movement comprising an analog display section and a drive section7 these sections being separately formed and very simply locked against each other through pawlgroove type locking means in a releasable manner. When the analog display section is locked relative to the drive section, an electrical connection can automatically be established between the substrates of the display and drive sections.

In such an arrangement, any one of various different types of analog display sections may selectively be combined with any one of various different types of drive sections.

Embodiments of the invention will now be described by way of example and with reference to the drawings, in which: Figure 1 is a longitudinal sectional view of the movement of a first clock, Figure 2 is a cross-sectional view of the movement shown in Figure 1, taken along a line II-II therein, Figure 3 is a front elevational view of the first clock during service, Figure 4 is a longitudinal sectional view of the movement of a second clock, Figure 5 is a view, partially broken away, of another clock movement, Figure 6 is a front elevational view of a clock which includes the movement shown in Figure 5, Figure 7 is a plan view, partially broken away, of still another clock movement, in which a clock gear train is disposed on a curved line, Figure 8 is a longitudinal sectional view of the movement of a third clock, Figure 9 is a cross-sectional view of the clock movement shown in Figure 8, taken along a line IX-IX therein, Figure 10 is a longitudinal sectional view of a drive section in a timepiece movement, Figure 11 is a cross-sectional view of the movement shown in Figure 10, taken along a line XI-XI therein, Figure 12 is a front elevational view of a clock which includes timepiece movements embodying the present invention, Figure 13 is a longitudinal sectional view of an analog display section in a timepiece movement, Figure 14 is a cross-sectional view of the analog display section shown in Figure 13, taken along a line XIV-XIV therein, Figure 15 is a longitudinal sectional view of a drive section in the movement shown in Figure 13, and Figure 16 is a perspective view showing the combination of the analog display section of Figures 13 and 14 with the drive section of Figure 15.

Referring now to Figures 1 and 2, there is shown a first preferred embodiment of a clock movement according to the present invention, which comprises a synchronous motor section, a clock gear train and a case divided into lower and upper case portions 10 and 12 between which the synchronous motor and time wheel train sections are housed and disposed.

As seen from Figure 2, each of the lower and upper case portions 10, 12 is of an elongated configuration and has a longitudinal axis aligned with a central stator axis 100 which will be described. The clock gear train is arranged in a line on the extension of said central stator axis 100.

Between the case portions 10 and 12 is located the synchronous motor section in the left-hand half of the case as viewed in Figure 1. The synchronous motor section includes a stator 14 which is of a longitudinally extending C-shaped configuration and made of a material having high magnetic permeability.

The stator 14 includes a pair of legs 14a and 14b extending parallel to each other. The central stator axis 100 extends between these legs 1Ma and 14b and is positioned to align with the longitudinal axis of the case portions 10 and 12.

One of the legs 14a in the stator 114 includes a bobbin 16 fixedly fitted thereover and a stator coil 18 wound about the bobbin 16. As be well-known in the art, the stator coil 18 receives synchronous driving pulses of a frequency normally equal to one Hz from 2 clock drive circuit (not sho) to create a magnetic flux required to drive the motor.

In the illustrated embodiment, each of the legs of the stator 14 is relatively long. Since the stator coil 18 is wound around the one leg 14a fully along the length thereof, the stator coil 18 has a large iiu1:ber of winbingt.

Thus, the stator 14 can produce a sufficiently large r.nacW uGe GI magnetic flux in comparison with the size of the clock movement according to the present invention. The stator 14 can provide a driving force sufficient to drive time indicating hands having their lengths longer than those of the conventional clocks.

The bobbin 16 includes a pair of engagement pawls 20a and 20b molded integrally therein. When the engagement pawls 20a and 20b engage a terminal plate 22, the stator 14 and the stator coil 18 are firmly held against the terminal plate 22. The terminal plate 22 is in turn secured rigidly in place between the case portions 10 and 12 by the fact that the distal ends of the engagement pawls 20a and 20b and one end of the bobbin 16 engage the inner walls of the case portions 10 and 12.

As seen from Figure 2, the terminal plate 22 includes at least two terminals 22a and 22b formed therein at one end. On assembling, the terminals 22a and 22b are externally exposed through an opening il formed between the case portions 10 and 12.

Thus, any other motor drive circuit or power supply can electrically be connected with the stator 14 easily by the use of any simple connector.

Each of the legs 14a and 14b in the stator 14 includes a stator pole 14c or 14d formed therein, which is in the form of a semi-circular recess as shown in Figure 2.

A rotor 24 is disposed between the stator poles 14c and 14d.

The rotor 24 includes a rotor pinion 26, a magnet receiver 28 formed integrally on the rotor pinion 26 and a rotor magnet 30 received in and fixed to the magnet receiver 28. The rotor pinion 26 and the magnet receiver 28 are rotatably supported between the .case portions 10 and 12 in a manner which will be described. Thus, the rotor magnet 30 magnetized into any number of magnetic poles can be rotated between the stator poles 14c and 14d. In the illustrated embodiment, the rotor 214 is rotatably supported by a stub 25 extending upwardly from the inner wall of the lower case portion 10 and a shaft-like bearing 27 extending downwardly from the inner wall of the upper case portion 12.

When the stator coIl 18 on the stator 14 receives a given pulse signal, a magnetic flux will be created in the stator poles 14c and 14d to drive the rotor 24 electromagnetically.

In the illustrated rotor 214, the rotor magnet 30 has a relatively large height to create an electromagnetic power effectively between the stator poles 14c and 14d. The rotor 24 with the rotor pinion 26 combined therewith provides an important factor limiting the thickness of the movement case which consists of the lower and upper case portions 10, 12. As will be described, the first reduction gear wheel engages the rotor pinion 26 and the time indicating gear train is completely received within the height of the rotor 24 to minimize the thickness of the clock movement case.

In such a manner, a synchronous motor section is formed between the case portions 10 and 12 so that the rotor 24 can be rotated in the normal intermittent feed manner or in the continuous feed manner if required. The rotation of the rotor 24 is transmitted to time indicating hands through the clock gear train.

The clock gear train may be divided into the first reduction wheel engaging the rotor pinion 26 of the rotor 24 and a time indicating gear train for transmitting the rotation from the first reduction wheel to the time indicating hands. At least the first reduction wheel is positioned on the central stator axis 100.

The first reduction wheel 32 is rotatably supported by a stub 34 extending upwardly from the inner wall of the lower case portion 10 and another stub 36 extending downwardly from the inner wall of the upper case portion 12. The first reduction wheel 32 includes a reduction pinion 32a formed integrally thereon which in turn is operatively connected with the time indicating gear train which will be described in more details.

As seen from Figure 2, the first reduction wheel 32 is located on the central stator axis 100. In addition, the central stator axis is positioned in an opening formed between the legs 14a and 14b of the stator 14 while the reduction pinion 32a is disposed at a position facing the distal opened end formed between the stator poles 114c and 14d. Therefore, neither of the stator leg 14a or 14b will have a through bore for rotatably receiving the first reduction wheel 32. This can make the clock movement compact.

The first reduction pinion 32a further engages a fourth wheel 38 including a fourth wheel pinion 38a which in turn engages a third wheel 140. The third wheel 140 has 2 third wheel pinion 40a engaging a center wheel 42. A center wheel pinion 44 is slidably fitted onto the center wheel 42 under the action of a given frictional force. A minute hand 46 is fixedly fitted over the center wheel plnion 44.

The fourth wheel 38 is provided with a central bore through which a shaft 48 extends from the upper case portion 12 to support the fourth wheel 38. The shaft 148 engages in a bearing 50 extending upwardly from the inner wall of the lower case portion 10.

On the other hand, the third wheel 140 is rotatably supported by a minute wheel shaft 52 journalled by the case portions 10 and 12. The minute wheel shaft 52 rigidly supports a minute wheel 54 which will be described.

The center wheel and pinion 142, 1414 are rotatably supported by a center wheel pipe receiver 56 which is fixedly mounted in the upper case portion 12.

The center wheel pinion 44 engages the minute wheel 5 having a minute wheel pinion 58 which in turn engages a hour hand wheel 60 rotatably supported by the center wheel pinion 44. A hour hand shaft 62 is formed integrally on the hour hand wheel 60 and fixedly supports a hour hand 62.

As described, the time indicating gear train includes the fourth wheel 38 engaging the first reduction wheel 32, the third wheel 40, the center wheel 42, the minute wheel 54 and the hour hand wheel 60 which are subsequently connected with the preceding one. In the first illustrated embodiment, the time indicating gear train is completely disposed on the extension of the central stator axis 100.

In such an arrangement, the rotational drive power can positively be transmitted from the rotor 24 through the first reduction wheel 32 via said time indicating gear train to the hour and minute hands 64, 46.

The first reduction wheel 32 and the time indicating gear train associated therewith are operatively supported between the upper and lower case portions 12, 10 in a line, in contrast with the conventional design requiring an intermediate plate and other elements. It is therefore impossible to create any misalignment of wheel shaft on assembling. Thus, the assembling can easily be automated while maintainig the wheel shafts very stably.

In addition, the coI"plete gear train is positionea within a thickness iess than the height of the rotor, so that the thickness of the movement case can be minimized in compatibility with the height of the rotor.

In the first embodiment, a time correction knob 66 is fixedly mounted on the minute wheel shaft 52 on the side of the upper case portion 12. When the knob 66 is rotated, the minute wheel and pinion 54, 58 are rotated to rotatably drive the center wheel pinion 44 and the hour hand wheel 60 into any desired correct position. At such a time, slippage is created between the center wheel pinion 44 and the center wheel 142 through any suitable slipping mechanism so that the synchronous motor section will not adversely be affected.

In accordance with the present invention, thus, the synchronous motor section includes the longitudinally extending C-shaped stator, the latter including its central axis on which at least the rotor and first reduction wheel in the synchronous motor section are positioned, and the time indicating gear trains disposed in a line on the extension of the central stator axis.

This results in an elongated movement having its whole reduced size. Longer time indicating hands can rotatably be driven by a larger drive power from the synchronous motor section. The elongated movement can contribute to the increased flexibility on designing the external appearance of clocks. Particularly, the elongated movement is very advantageous for concealed movement type clocks.

I he minute and hour hands 46 and 64 are rigidly connected on the forwardmost end of the time indicating gear train, that is, the respective one of the center and hour-hand wheels 142, 60. By such a fact that the time indicating hands are fixedly connected with the time indicating gear train, no other gear train or movement part will be arranged about the time indicating shaft.

There is thus a large available space through a segment shown by A in Figure 2. Such a space may extend through an angle more than 200". This can very increase the flexibility on clock design.

Figure 3 shows a table clock to which the present invention is applied. This table clock comprises a base 70, a support column 72 fixedly mounted on the base 70 and an indicator plate 74. In the illustrated construction, the indicator plate 74 is a transparent disc framed by a frame 76.

The clock movement according to the present invention is completely housed within the strut 72, the top portion of which supports the hour and minute hands 64, 146.

Such an arrangement gives a unique appearance to the clocK, WhiCh if one views this clock, one CaììIlOt readily locate tne clock movement since it appears to him that the time indicating hands are substantially surrounded by the transparent plate with only the strut 73 supporting the time indicating hands.

Figure 4 shows a second embodiment of the present invention in which parts similar to those of Figure 1 are denoted by similar reference numerals with a further description thereof being omitted.

The second embodiment has the feature that the clock gear train includes center and hour-hand wheels 42, 60 of the time indicating gear train and a minute wheel 54 arranged in a manner different from that of the first embodiment. Thus, hour and minute hands 64, 46 are positioned closer to a synchronous motor.

In the second embodiment, a third wheel 40 is rotatably supported by a stub 80 extending upwardly from the inner wall of a lower case portion 10 and a stub 82 extending downwardly from the inner wall of an upper case portion 12.

As described, the first embodiment of the present invention includes the time indicating shaft disposed at the outermost periphery of the clock movement such that the available space about the time indicating shaft will be large, as shown in Figure 3. In the second embodiment, however, such an advantage is sacrificed to provide another advantage in that the time indicating shaft can be displaced toward the center of the length of the clock movement.

Referring no to Figure 5, there is shown another embodiment of the present invention in which a clock movement includes a battery and a drive control circuit, all of which are completely housed within the interior of the clock movement. As shown in Figure 5, a case 84 contains a battery and drive control circuit 86, 88 disposed on the extension of the central stator axis 100.

Thus, all the parts required by the elongated movement can be assembled thereinto. As shown in Figure 6, for example, a clock movement including said battery and circuit can be incorporated into the interior of a strut 72 which is fixedly mounted on a base 70. In such an arrangement, a decorative plate 74 made of a transparent sheet material can be used to provide a concealed movement type clock in which the whole drive mechanism is completely concealed by the strut 72.

Although the aforementioned embodiments of the present invention have been described as to the time indicating gear train disposed on the extension of the central stator axis, the present invention may be embodied to provide a time indicating gear train arranged on a line curved or turned along the central stator axis.

Figure 7 shows still another embodiment of the present invention in which a time indicating gear train is disposed on a curved line. This embodiment is constructed of components substantially similar to those of Figure 2. Therefore, similar parts are denoted by similar reference numerals and a further description thereon will be omitted.

In Figure 7, a first reduction wheel 32 and a time indicating gear train (38, 40 and 42) engaging the wheel 32 are arranged along an arcuate or curved line 200 contacting the central stator axis 100. As a result, case portions 12 and 10 also are of a curved outline corresponding to said arcuate line 200.

A clock movement of such a curved configuration can be applied to a clock having a unique design in which a curved strut supports time indicating hands at its forwardmost end.

As will be apparent from the foregoing, the present invention provides a unique clock design which comprises an elongated clock movement including a synchronous motor section and a clock gear train, the elongated clock movement serving as a clock drive incorporated into the clock and concealed as possible.

Referring now to Figures 8 and 9, there is shown a third preferred embodiment of a clock movement according to the present invention, which comprises a synchronous motor section1 a clock gear train and a case divided into lower and upper case portions 210 and 212 between which the synchronous motor and time wheel train sections are housed and disposed.

As seen from Figure 9, each of the lower and upper case portions 210, 212 is of an elongated configuration and has a longitudinal axis aligned with a central stator axis 100 which will be described. The clock gear train are arranged in a line on the extension of said central stator axis 100.

Between the case portions 210 and 212 is located the synchronous motor section in the left-hand half of the case as viewed in Figure 8. The synchronous motor section includes a stator 214 which is of a longitudinally extending C-shaped configuration and made of a material having high magnetic permeability. The stator 14 includes a pair of legs 214a and 214b extending parallel to each other. The central stator axis 100 extends between these legs 214a and 214b and is'positioned to align with the longitudinal axis of the case portions 210 and 212.

One of the legs 214a in the stator 214 includes a bobbin 216 fixedly fitted thereover and a stator coil 218 wound about the bobbin 216. As be well-known in the art, the stator coil 218 receives synchronous driving pulses of a frequency normally equal to one Hz from a clock drive circuit (not shown) to create a magnetic flux required to drive the motor.

In the illustrated embodiment, each of the legs of the stator 214 has is relatively long. Since the stator coil 218 is wound around the one leg 214a fully along the length thereof, the stator coil 218 has a large number of windinss.

Thus, the stator 214 can produce a sufficiently large magnitude of magnetic flux in comparison with the size of the clock movement according to the present invention. The stator 214 can provide a driving force suffIcient to drive time indicating hands having their lengths longer than those of the conventional clocks.

The bobbin 216 includes a pair of engagement pawls 220a and 220b molded integrally therein. When the engagement pawls 220a and 220b engage a terminal plate 222, the stator 214 and the stator coil 218 are firmly held against the terminal plate 222.

The terminal plate 222 is in turn secured rigidly in place between the case portions 210 and 212 by the fact that the distal ends of the engagement pawls 220a and 220b and one end of the bobbin 216 engage the inner walls of the case portions 210 and 212.

As seen from Figure 9, the terminal plate 222 includes at least two terminals 222a and 222b formed therein at one end. On assembling, the terminals 222a and 222b are externally exposed through an opening 210a formed between the case portions 210 and 212. Thus, any other motor drive circuit or power supply can electrically be connected with the stator 14 easily by the use of any simple connector.

Each of the legs 214a and 214b in the stator 21 includes a stator pole 214c or 214d formed thereIn, which is In the form of a semi-circular recess as shown in Figure 9.

A rotor 224 is disposed between the stator poles 2114c and 214d. The rotor 224 includes a rotor pinion 226, a magnet receiver 228 formed integrally on the rotor pinion 226 and a rotor magnet 230 received in and fixed to the magnet receiver 228. The rotor pinion 226 and the magnet receiver 228 are rotatably supported between the case portions 210 and 212 in a manner which will be described. Thus, the rotor magnet 230 magnetized into any number of magnetic poles can be rotated between the stator poles 2114c and 21d. In the illustrated embodiment, the rotor 224 is rotatably supported by , stub 225 extending upwardly from the inner wall of the lower case portion 210 and a shaft-like bearing 227 extending downwardly from the inner wall of the upper case portion 212.When the stator coil 218 on the stator 214 receives a given pulse signal, a magnetic flux will be created in the stator poles 214c and 214d to drive the rotor 224 electromagnetically.

In such a manner, a synchronous motor section is formed between the case portions 210 and 212 so that the rotor 224 can be rotated in the normal intermittent feed manner or in the continuous feed manner if required. The rotation of the rotor 224 is transmitted to time indicating hands through the clock gear train.

The clock gear train may be divided into the first reduction wheel engaging the rotor pinion 226 of the rotor 224 and a time indicating gear train for transmitting the rotation from the first reduction wheel to the time indicating hands. At least the first reduction wheel is positioned on the central stator axis 100.

The first reduction wheel 232 is rotatably supported by a stub 234 extending upwardly from the inner wall of the lower case portion 210 and another stub 236 extending downwardly from the inner wall of the upper case portion 2i2. The first reduction wheel 232 includes a reduction pinion 232a formed integrally thereon which in turn is operatively connected with the time indicating gear train which will be described in more details.

As seen from Figure 9, the first reduction wheel 232 is located on the central stator axis 100. In addition, the central stator axis is positioned in an opening formed between the legs 214a and 214b of the stator 214 while the reduction pinion 232a is disposed at a position facing the distal opened end formed between the stator poles 214c and 214d. Therefore, neither of the stator leg 214a or 214b will have a through bore for rotatably receiving the first reduction wheel 232. This can make the clock movement compact.

The first reduction pinion 232a further engages a fourth wheel 238 including a fourth wheel pinion 238a which in turn engages a third wheel 240. The third wheel 240 has a third wheel pinion 240a engaging a center wheel 242. A center wheel pinion 244 is slidably fitted onto the center wheel 242 under the action or a given frictional force. A minute hand 246 is fixedly fitted over the center wheel pinion 21414.

The fourth wheel 238 is provided with a central bore through which a shaft 248 extends from the upper case portion 212 to support the fourth wheel 238. The shaft 248 engages in a bearing 250 extending upwardly from the inner wall of the lower case portion 210.

On the other hand, the third wheel 240 is rotatably supported by a minute wheel shaft 252 journalled by the case portions 210 and 212. The minute wheel shaft 252 rigidly supports a minute wheel 254 which will be descrIbed.

The center wheel and pinion 242, 244 are rotatably supported by a center wheel pipe receiver 256 which is fixedly mounted in the upper case portion. 212.

The center wheel pinion 244 engages the minute wheel 254 having a minute wheel pinion 258 which in turn engages a hour hand wheel 260 rotatably supported by the center wheel pinion 244. A hour hand shaft 262 is formed integrally on the hour hand wheel 260 and fixedly supports a hour hand 262.

As described, the time indicating gear train includes the fourth wheel 238 engaging the first reduction wheel 232, the third wheel 240, the center wheel 242, the minute wheel 2514 and the hour hand wheel 260 which are subsequently connected with the preceding one. As lathe first illustrated embodiment, the time indicating gear train is completely disposed on the extension of the central stator axis 100.

In tne srrllelnenr, describea, the rotational drive power can be positively transmitted from the rotor 224 through the first reduction wheel 232 via said time indicating gear train to the hour and minute hands 264, 246.

In the third embodiment, a time correction knob 266 is fixedly mounted on the minute wheel shaft 252 on the side of the upper case portion 212. When the knob 266 is rotated, the minute wheel and pinion 254, 258 are rotated to rotatably drive the center wheel pinion 244 and the hour hand wheel 260 into any desired correct position. At such a time, slippage is created between the center wheel pinion 244 and the center wheel 242 through any suitable slipping mechanism so that the synchronous motor section will not adversely be affected.

In accordance with the present invention, thus, the synchronous motor section includes the longitudinally extending C-shaped stator, the latter including its central axis on which at least the rotor and first reduction wheel in the synchronous motor section are positioned, and the time indicating gear trains disposed in a line on the extension of the central stator axis.

This results in an elongated movement having its whole reduced size. Longer time indicating hands can rotatably be driven by a larger drive power from the synchronous motor section. The elongated movement can contribute to the increased flexibility on designing the external appearance of clocks. Particularly, the elongated movement is very advantageous for concealed movement type clocks.

A removable battery lid 211 also is mounted in the lower case portion 210 at the left-hand half thereof as viewed in Figures 8 and 9. The battery lid 211 receives a battery 213 and a motor drive circuit 217 fixedly mounted on a circuit substrate 215.

The battery 213 is thus arranged on the opposite side of the stator 214 relative to the gear train and particularly the rotor 224 and in a direction perpendicular to the orientation of the gear train. The stator 214 is of an elongated C-shape, one end of which receives the rotor 2214. On the extension of the other end of the stator 214 is located the battery 213 which is sufficiently separated from the rotor as seen from Figures 8 and 9.Even when a magnetic flux in the rotor 224 is increased, any magnetic attraction between tne tne battery 213 ai;C three rotor 224 vlil be pusitn vely prevented fron arising.

In such a manner, the magnetic flux In the rotor 224 can be increased to provide a small-sized clock movement having an increased drive power without any inclination of the rotor 224 relative to the battery 213 and so on.

Figures 10 and 11 show a further preferred embodiment cf the present invention in which a drive section is formed separately from said analog display section.

The drive section includes a lower case portion 370, an electromagnetic lid 372 removably mounted on the lower case portion 370 and an upper case portion 374 detachably mounted on the lower case portion 370. The lower case portion 370 rigidly receives a drive circuit substrate 376.

The lower case portion 370 has an elongated configuration similar to those of the lower and upper case portions 10, 12 in the analog display section. A battery 378 is mounted longitudinally within the interior of the lower case portion 37tO.

In order to hold the battery 378, the drive circuit substrate 376 includes terminal tabs 380 and 382 rigidly mounted thereon. As be well-known in the art, the battery 378 is held between the terminal tabs 380 and 382.

As shown, the drive circuit substrate 376 also includes a drive circuit printed thereon, the drive circuit including a motor drive IC 384. The drive circuit substrate 376 is formed at one end with terminals 376a and 376b which can easily receive leads through an opening 370a formed between the case portions 370 and 374.

By soldering the lead wires or FPC's to the exposed terminals, the drive section shown in Figures 10 and 11 can very easily be connected electrically zith the analog display section shown in Figures 1 and 2 while maintaining the respective sections at any separated locations.

Figure 12 shows a further embodiment of the present invention in which a plurality of analog display sections as aforementioned can be driven by a single drive section. Three analog display sections 401, 402 and 403, which are identical with the analog display section shown in Figures 1 and 2, are adapted to display times in a plurality of countries which have time differentials.

In accordance with the present invention, each of these three analog display sections 401, 402 and 403 can very be miniaturized as described and easily be housed within the interior of an outer case 404.

The analog display sections 401, 402 and 403 are simultaneously driven by a drive section 406 completely mounted within a base 405. The drive section 406 has the same construction as shown in Figures 10 and 11.

In Figure 12, the drive section 406 is electrically connected with the respective analog display sections through flexible wirings, for example, through leads 4U5, 4 and 409 in the illustrated embodiment. Therefore, the analog display sections 401, 402 and 403 can be arranged at any locations separated from one another and from the drive section 1406.

As will be apparent from the foregoing, the present invention can provide a concealed movement type clock having an increased flexibility of design, which can corprise an analog display section including a synchronous motor section and a clock gear train and a drive section including a battery and a drive circuit, these sections being electrically connected with each other through flexible wiring and capable of being arranged at any separated locations, thereby being particularly able to decrease the size of the analog display section.

Since the analog display section and the drive sectioncanbe separated from each other according to the present invention, a plurality of analog display sections can be driven by a single drive section. Otherwise, a plurality of drive sections having different capacities may be used to drive a plurality of analog display sections having hands of different lengths, respectively.

Furthermore, the present invention can provide a unique clock design in which the clock drive section can be concealed as possible by providing an elongated clock movement including a synchronous motor section and a clock gear train.

Referring now to Figures 13 and 14, there is shown a fourth preferred embodiment of a clock movement according to the present invention, which comprises a synchronous motor section, a clock gear train and a case divided into lower and upper case portions 510 and 512 between which the synchronous motor and time wheel train sections are housed and disposed.

As seen from Figure 14, each of the lower and upper case portions 510, 512 is of an elongated configuration and has a longitudinal axis aligned with a central stator axis 100 which will be described. The clock gear train are arranged in a line on the extension of said central stator axis 100.

The fourth embodiment hiss tie featur-e in tiiat -che rnovenflt case of said analog display section is provided with pawl means for releasably and mechanically connecting the movement case with a drive section as will be described. The pawl means includes pawl portions 510a and 512a extending from the respective lefthand ends of the. case portions 510 and 512.

The case portions 510 and 512 are molded of a plastic material. As a result, the pawl portions 510a and 512a are flexible and can then be connected detachably with any drive section.

Between the case portions 510 and 512 is located the synchronous motor section in the left-hand half of the case as viewed in Figure 13. The synchronous motor section includes a stator 514 which is of a longitudinally extending C-shaped configuration and made of a material having high magnetic permeability. The stator 514 includes a pair of legs 5114a and 51b extending parallel to each other. The central stator axis 100 extends between these legs 5141a and 514b and is positioned to align with the longitudinal axis of the case portions 510 and 512.

One of the legs 514a in the stator 514 includes a bobbin 516 fixedly fitted thereover and a stator coil 518 wound about the bobbin 516. As is well-known In the art, the stator coil 518 receives synchronous driving pulses of a frequency normally equal to one Hz from a clock drive circuit (not shown) to create a magnetic flux required to drive the motor.

In the illustrated embodiment, each of the legs of the stator 514 is reia ely long. Since z..e stator coil 518 is wound around the one leg 5114a fully along the length thereof, the stator coil 518 has a large number uf windings.

Thus, the stator 514 can produce a sufficiently large magnitude ot magnetic flux in comparison with the size of the clock movement according to the present invention. The stator 514 can provide a driving force sufficient to drive time. indicating hands having their lengths longer than those of conventio-nal clocks.

The bobbin 516 includes a pair of engagement pawls 520a and 520b molded integrally therein. When the engagement pawls 520a and 520b engage a terminal plate 522, the stator 514 and the stator coil 518 are firmly held against the terminal plate 522.

The terminal plate 522 is in turn secured rigidly in place between the case portions 510 and 512 by the fact that the distal ends of the engagement pawls 520a and 520b and one end of the bobbin 516 engage the inner walls of the case portions 510 and 512.

As seen from Figure 14, the terminal plate 522 includes at least two terminals 522a and 522b formed therein at one end. On assembling, the terminals 522a and 522b are externally exposed through an opening 511 formed between the case portions 510 and 512. Thus, any other motor drive circuit or power supply can electrically be connected with the stator 514 easily by the use of any simple connector.

Each of the legs 514a and 514b in the stator 514 Includes a stator pole 5114c or 514d formed therein, which is in the form of a semi-circular recess as shown in Figure 114.

A rotor 524 is disposed between the stator poles 514c and 514d. The rotor- 524 includes a rotor pinion 526, a magnet receiver 528 formed integrally on the rotor pinion 526 and a rotor magnet 530 received in and fixed to the magnet receiver 528. The rotor pinion 526 and the magnet receiver 528 are rotatably supported between the case portions 510 and 512 in a manner which will be described. Thus, the rotor magnet 530 magnetized into any number or magnetic poles can be rotated between the stator poles 5114c and 514d. In the illustrated embodiment, the rotor 524 is rotatably supported by a stub 525 extending upwardly from the inner wall of the lower case portion 510 and a shaft-like bearing 527 extending downwardly from the inner wall of the upper case portion 512.When the stator coil 518 on the stator 514 receives a given pulse signal, a magnetic flux will be created in the stator poles 514c and 51d to drive the rotor 524 electromagnetically.

In such a manner, a synchronous motor section is formed between the case portions 510 and 512 so that the rotor 524 can be rotated in the normal intermittent feed manner or in the continuous feed manner if required. The rotation of the rotor 524 is transmitted to time;indicating hands through the clock gear train.

The clock gear train may be divided into the first reduction wheel engaging the rotor pinion 526 of the rotor 5214 and a time indicating gear- train for transmitting the rotation from the first reduction wheel to the time indicating hands. At least the first reduction wheel is positioned on the central stator axis 100.

The first reduction wheel 532 is rotatably supported by a stub 534 extending upwardly from the inner wall of the lower case portion 510 and another stub 536 extending downwardly from the inner wall of the upper case portion 512. The first reduction wheel 532 includes a reduction pinion 532a formed integrally thereon which in turn is operatively connected with the time indicating gear train which will be described in more detail.

As seen from Figure 14, the first reduction wheel 532 is located on the central stator axis 100. In addition, the central stator axis is positioned in an opening formed between the legs 514a and 514b of the stator 514 while the reduction pinion 532a is disposed at a position facing the distal opened end formed between the stator poles 514c and 514d. Therefore, neither of the stator legs 5114a or 514b will have a through bore for rotatably receiving the first reduction wheel 532. This can make the clock movement compact.

The first reduction pinion 532a further engages a fourth wheel 538 including a fourth wheel pinion 538a which in turn engages a third wheel 540. The third wheel 540 has a third wheel pinion 540a engaging a center wheel 542. A center wheel pinion 544 is slidably fitted onto the center wheel 542 under the action of a given frictional force. A minute hand 546 is fixedly fitted over the center wheel pinion 51414.

The fourth wheel 538 is provided with a central bore through which a shaft 548 extends from the upper case portion 512 to support the fourth wheel 538. The shaft 548 engages in a bearing 550 extending upwaraly from the inner wall of the lower case portion 510.

On the other hand, the third wheel 540 is rotatably supported by a minute wheel shaft 552 journalled by the case portions 510 and 512. The minute wheel shaft 552 rigidly supports a minute wheel 554 which will be described.

The center wheel and pinion 542, 544 are rotatably supported by a center wheel pipe receiver 556 which is fixedly mounted in the upper case portion 512.

The center wheel pinion 544 engages the minute wheel 554 having a minute wheel pinion 558 which in turn engages a hour hand wheel 560 rotatably supported by the center wheel pinion 544. A hour hand shaft 562 is formed integrally on the hour hand wheel 560 and fixedly supports a hour hand 562.

As described, the tirte indicating gear train includes the fourth wheel 538 engaging the first reduction wheel 532, the third wheel 540, the center wheel 52, the minute wheel 554 and the hour hand wheel 560 which are subsequently connected with the preceding one. In the first illustrated embodiment, the time indicating gear train is completely disposed on the extension of the central stator axis 100.

In such an arrangement, the rotational drive power can positively be transmitted from the rotor 524 through the first reduction wheel 532 via said time indicating gear train to the hour and minute hands 564, 546.

In the fourth embodiment, a time correction knob 566 is fixedly mounted on the minute wheel shaft 552 on the side of the upper case portion 512. When the knob 566 is rotated, the minute wheel and pinion 554, 558 are rotated to rotatably drive the center wheel pinion 544 and the hour hand wheel 560 into any desired correct position. At such a time, slippage is created between the center wheel pinion 544 and the center wheel 542 through any suitable slipping mechanism so that the synchronous motor section will not adversely be affected.

rie syncflronous Tractor sect" ion thus includes tne longitudinally teing ---- C-shaped stator, the latter including its central axis on which at least the rotor and first reduction wheel in the synchronous motor section are positioned, and the time indicating gear trains disposed in a line on the extension of the central stator axis.

This results in an elongated movement having its whole reduced size. Longer time indicating hands can rotatably be driven by a larger drive power from the synchronous motor section. The elongated movement can contributes to the increased flexibility in designing the external appearance of clocks. Particularly, the elongated movement is very advantageous for concealed movement type clocks.

Figure 15 shows the drive section of the fourth embodiment of the present invention. The drive section includes a lower case portion 570, a battery lid 572 and an upper case portion 574, the lower case portion 570 fixedly receiving a drive circuit substrate 576.

The battery lid 572 can easily be mounted detachably on the lower case portion 570 in any well-known manner. A battery 578 can easily be mounted removably between battery holders 580 and 582 which are rigidly attached to the drive circuit substrate 576.

The drive circuit substrate 576 includes a drive circuit including a drive IC 584, which circuit is printed on the substrate 576. The drive circuit is adapted to supply a given drive signal, for example, a drive pulse of one Hz to the synchronous motor section in the aforementioned analog display section.

In the illustrated construction, the drive section has case portions 570 and 574 which are provided with groove means for mechanically connecting the drive section with the analog display section. The groove means comprises grooves 570a and 574a formed respectively on the right-hand ends of the case portions 570 and 574. These grooves 570a and 574a respectively engage pawls 510a and 512a formed on the case portions 510 and 512 of the analog display section to connect the drive section with the analog display section mechanically and easily.

The mechanical connection between the drive and display sections simultaneously causes an electrical connection therebetween. For such a purpose, the drive circuit substrate 576 has one end outwardly extending from its right-hand side as viewed in Figure 15, as shown by 576a in Figure 15. The bottom face of the drive circuit substrate 576 includes terminals 576b and 576c formed thereon in a pattern.

In such a manner, the terminals 522a and 522b on the terminal plate 522 of the analog display section can be contacted, under pressure, by the terminals 576b and 576c on the drive circuit substrate 576 when the analog display section is mechanically connected with the drive section. This secures an electrical connection between the drive and display sections in positive and easy manner.

Each of the terminal plate 522 and circuit substrate 576 is made of a resilient material such as plastics. When the terminals 522a and 522b contact the terminals 576b and 576c, these terminals can more effectively be urged toward each other to provide a very well contact pressure. Thus, the electrical connection can be obtained very well under such a contact pressure due to the resilient deformation of the terminal plate and substrate.

Figure 16 shows the assembled construction of the aforementioned clock movement in which an analog display section 601 can be positively connected with a drive section 602 by engaging the pawls 510a and 512a of the analog display section 601 with the grooves 574a (570a) of the drive section 602 in such a state that the drive and display sections are longitudinally aligned with each other.

In the illustrated construction, such a mechanical connection between the drive and display sections can easily provide an electrical connection between the terminal plate 522 or the analog display section 601 and the circuit substrate 576 of the drive section 602 due to the resilient contact of the respective terminals under pressure.

As seen from Figure 16, the analog display section 601 is longitudinally aligned with the drive section 602 to form an elongated movement as a whole. The small-sized movement of such an elongated and thinned configuration can make the external design of the clock case more flexible.

Although the construction shown in Figure 15 has been described as to the mechanical connection accomplished by using the pawls on the analog display section and the grooves on the drive section, such an arrangement may be reversed optionally witnin the scope or the present invention.

As will be apparent from the foregoing, the analog display and drive sections may be separated from each other and easily connected removably with each other by the use of a pal and groove connection mechanism. Furthermore, the drive and display sections may easily be connected electrically ith each other due to the resilient deformation of the terminals and circuit substrate. It is therefore possible to optionally combine one of different analog display sections with one of the different drive sections to form a new and unique movement.

Claims (13)

1. A clock movement comprising an elongate Cshaped stator having a pair of parallel legs, the stator including a central axis extending parallel to the legs and therebetween, the distal ends of the legs being opposed to each other to form stator poles facing each other, and one of the legs including a stator coil wound thereabout, a rotor located between the stator poles and rotatably supported within elongate case means of the movement, a first reduction wheel located on the stator central axis and engaging a rotor pinion on the rotor, a time-indicating gear train operatively connected to the first reduction wheel, and timeindicating hands supported on a part of the gear train, the gear train from the rotor to the time-indicating gear train being arranged on a straight or curved line extending along or from adjacent the central stator axis.

2. A clock movement according to claim 1, wherein the time-indicating gear train is arranged in a straight line along the stator central axis.

3. A clock movement according to claim 1 or 2, wherein the first reduction wheel has a central axis located within an opening formed between said stator poles.

4. A clock movement according to any preceding claim, wherein the time indicating-hands are supported on the distal end wheel of the time-indicating gear train.

5. A clock movement according to any preceding claim, wherein the first reduction wheel and the timeindicating gear train are supported between first and second case portions of the case means.

6. A clock movement according to any preceding claim, wherein the first reduction wheel and the time indicating gear train are located within the height of the rotor.

7. A clock movement according to any preceding claim, including battery-reception means for supplying a drive current to the stator coil, the batteryreception means being disposed on the side of the stator opposite the clock gear train.

8. A clock comprising a clock movement according to any preceding claim and a drive section comprising battery-reception means and a motor drive circuit for supplying a drive signal to the clock movement which is electrically connected to the drive section by conductor means for the drive signal.

9. A clock comprising an analog display section and a drive section, the display section including a movement comprising a synchronous motor and a clock gear train, the synchronous motor including a stator linearly aligned with the clock gear train, the drive section including battery-reception means and a drive circuit, the display and drive sections being detachably mechanically and electrically connected by means forming a mechanical and electrical connection between the sections.

10. A clock according to claim 9, wherein the connection means comprises a mechanical connection means comprising pawl means on one of the display and drive sections and groove means on the other.

11. A clock according to claim 9 or 10, wherein the connection means comprises an electrical connection means comprising respective terminal means on a stator substrate of the analog display section and on a circuit substrate of the drive section.

12. A clock according to claim 9, l0 cr 11, wherein the movement is according to any of claims # to 7.

13. A clock or clock movement substantially as hereinbefore described with reference to Figures 1 to 3, Figures 4 to 6, Figure 7, Figures 8 and 9, Figures 10 and 11, Figure 12, or Figures 13 to 16 of the drawings.