Patent ID: 12204283

DETAILED DESCRIPTION

With respect to the use of plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

Hereinafter, an embodiment of a reciprocating display mechanism and a timepiece including the reciprocating display mechanism according to the present disclosure will be described with reference to the accompanying drawings.

A configuration will be described.FIG.1is a plan view illustrating a timepiece100including a fan-shaped display mechanism10as an embodiment of a reciprocating display mechanism according to the present disclosure.FIG.2is view illustrating a movement of the timepiece100, as seen from a back cover side of the timepiece, including the fan-shaped display mechanism10illustrated inFIG.1.FIG.3is a perspective view of a hand driving wheel12, as seen from a dial plate40side of the timepiece100, in the fan-shaped display mechanism10illustrated inFIG.1. Note that the timepiece100is also an embodiment of the timepiece according to the present disclosure.

The illustrated timepiece100includes an hour hand51and a minute hand52. The timepiece100displays a time with the hour hand51and the minute hand52that indicate hour marks such as numbers and index bars displayed on the dial plate40. InFIG.1, the hour marks are omitted.

The dial plate40includes in a region thereof in the six o'clock direction (lower region of dial plate40) a small hand region60. A second hand53is provided in the small hand region60.

The dial plate40includes in a region thereof in the twelve o'clock direction the fan-shaped display mechanism10. The dial plate40includes in the twelve o'clock region thereof (upper region of dial40plate) a fan-shaped display region41having a fan-shaped contour with about 120 degrees of the center angle. The fan-shaped display region41has a circular arc of the fan toward the center of the dial plate40and a pivot of the fan toward the twelve o'clock region.

Not shown scales are provided on the fan-shaped display region41. The scales are provided at predetermined intervals (may be equal angle intervals as example) in a circumference direction with the pivot of the fan as a center. The scales show a variable physical quantity such as power reserve of a battery that is a driving source for driving the timepiece100, for example.

The fan-shaped display mechanism10reciprocates an after-described hand11in a circular arc shape within in a fixed area including the fan-shaped display region41to perform predetermined display. In this embodiment, the hand11indicates the scale displayed on the fan-shaped display region41in the fixed area within which the hand11reciprocates, so as to inform a user of the timepiece100of the power reserve of the battery.

As described above, the hand11moves in an area having an angle area wider than that of the fan-shaped display region41on which the scales are displayed. However, the area that recognizably displays the power reserve of the battery is only the area of the fan-shaped display region41on which the scales are displayed.

The fan-shaped display mechanism10includes the hand11, a hand driving wheel12, an intermediate wheel14(example of transmission wheel), and a kick spring (torsion coil spring)13(example of biasing member).

The hand driving wheel12includes a wheel121and a shaft125that are integrated, as illustrated inFIG.3. The hand11is fixed to the shaft125, and the hand11and the hand driving wheel12integrally rotate about the shaft125.

The wheel121includes an angle area123(angle area of 164 degrees as example) about half of one round. The teeth122are provided only in the angle area123. That is, the teeth122are not provided in the entire circumference of the wheel121about the shaft125. The teeth122engage with a pinion14b(refer toFIGS.4to9) of the intermediate wheel14.

The wheel121includes a region adjacent to the angle area123provided with the teeth122. An idle region124in which the pinion14bof the intermediate wheel14engaging with the teeth122idles is provided in one part of the region adjacent to the angle area123provided with the teeth122. The idle region124has a radius or less corresponding to the radius at the bottom of the tooth122provided in the wheel121, so that the pinion14bidles. The idle region124has a length of one module or more over a pitch circle (reference circle) of the wheel121.

A stopper129is provided in the other part of the region adjacent to the angle area123provided with the teeth122, which is opposite to the idle region124. A tooth of the pinion14bthat rotates by engaging with the teeth122contacts the stopper129, so that the stopper129stops the rotation of the intermediate wheel14.

The stopper129in this embodiment has a radius corresponding to the radius at the addendum of the tooth122, but the radius of the stopper129is not limited thereto. The stopper129may have a radius larger or smaller than the radius at the addendum of the tooth122as long as it stops the rotation of the pinion14bwhen the tooth of the pinion14bcontacts the stopper129.

The wheel121includes, on one surface thereof (for example, surface toward dial plate40), a cylindrical projection126projecting in the direction of the shaft125. The projection126has a circumference surface that contacts an arm portion13aof the after described kick spring13, and the projection126presses the arm portion13aaccording to the rotation of the wheel121to elastically deform a coil portion of the kick spring13to be twisted.

The wheel121also includes, on the same surface on which the projection126is provided, two substantially cylindrical projections127similar to the projection126. Different from the projection126, the projections127do not impact on another member, and are provided to keep a weight balance with the projection126.

It is thus preferable for the three projections126,127,127to have a similar mass, and to be disposed at substantially equal angle intervals about the shaft125. The number of the projections127is not limited to two. For example, three or more projections or a single projection may be provided. When the weight balance is not considered, the projection127may be omitted.

The intermediate wheel14includes a wheel14aand the pinion14bwhich are coaxially and integrally provided. The pinion14bhas the number of teeth less than that of the wheel14a. The wheel14aengages with a not shown wheel fixed coaxially to a rotor21of a stepping motor20. The pinion14bengages with the teeth122of the wheel121of the hand driving wheel12. The rotation of the rotor21of the stepping motor20is thereby transmitted to the hand driving wheel12through the intermediate wheel14.

The kick spring13presses (biases) the wheel121, that is driven in the clockwise direction, in the counterclockwise direction.

FIGS.4to9are plan views describing the engagement state of the pinion14band the angle area123provided with the teeth122of the wheel121of the hand driving wheel12and the positional relationship between the fan-shaped display region41and the hand11.

As illustrated inFIGS.4to9, the stepping motor20is set such that the rotation of the rotor21in the normal rotation direction becomes the rotation in the clockwise direction as seen from the dial plate40side. Accordingly, the intermediate wheel14rotates in the counterclockwise direction by the rotation of the rotor21in the normal rotation direction, and the hand driving wheel12rotates in the clockwise direction. That is, the rotation direction of the intermediate wheel14when the engagement with the intermediate wheel14as the transmission wheel advances toward the idle region124from the area provided with the teeth122of the wheel121is set according to the normal rotation direction of the stepping motor20that rotates the intermediate wheel14.

The intermediate wheel14rotates in the clockwise direction and the hand driving wheel12rotates in the counterclockwise direction by the rotation of the rotor21in the reverse rotation direction (rotation in counterclockwise direction as seen from dial plate40side).

Next, the relationship between the angle area123(seeFIG.3) provided with the teeth122of the wheel121of the hand driving wheel12and the position of the hand11will be described.

FIG.4shows that the hand driving wheel12rotates such that the pinion14bengages with the leading end tooth122of the angle area123provided with the teeth122in the clockwise direction (rear end tooth in counterclockwise direction), and the pinion14bcontacts the stopper129adjacent to the angle area123provided with the teeth122, so that the wheel121stops rotating in the counterclockwise direction.

Although the teeth122of the wheel121rotate when the pinion14bof the intermediate wheel14engages with the teeth122, the pinion14bis inhibited from rotating in the clockwise direction, and stops when the pinion14bcontacts the stopper129.

In this state, the rotor21rotates in the reverse rotation direction (counterclockwise direction), the intermediate wheel14engaging with the wheel coaxial with the rotor21rotates in the clockwise direction, and the pinion14bcontacts the stopper129to be inhibited from rotating in the clockwise direction. The hand driving wheel12is also inhibited from rotating in the counterclockwise direction, and stops.

Accordingly, in the state illustrated inFIG.4, the hand11fixed to the hand driving wheel12locates in the leading end edge of the rotatable area in the counterclockwise direction (rear end edge in clockwise direction). In addition, in this position, the hand11dislocates from the fan-shaped display region41in the counterclockwise direction.

In the state illustrated inFIG.4, although the rotor21cannot further rotate in the reverse rotation direction from the stopped state, the stepping motor20can rotate the rotor21by switching the rotation direction of the rotor21into the normal rotation direction (clockwise direction) without slightly rotating the rotor21in the reverse rotation direction.

InFIGS.5to9, with the position of the projection126of the hand driving wheel12in the state illustrated inFIG.4as a reference position, the projection126in this reference position is shown by a two-dot chain line of a virtual line.

FIG.5shows that the pinion14brotates in the clockwise direction from the reference position (state inFIG.4) in which the pinion14bcontacts the stopper129, and the hand11is aligned with the leading end edge of the fan-shaped display region41in the counterclockwise direction (rear end edge in clockwise direction).

In this case, the wheel121rotates at an angle of α degree in the clockwise direction from the position of the projection126in the reference position illustrated inFIG.4to the position in which the hand11is aligned with the leading end edge of the fan-shaped display region41illustrated inFIG.5.

FIG.5shows that the pinion14bengages with the tooth122in the angle area123provided with the teeth122, and is rotatable both in the clockwise direction and the counterclockwise direction. The state illustrated inFIG.5is reached from the reference position illustrated inFIG.4by inputting a previously set predetermined number of driving signals (for example, step signal) into the stepping motor20.

Herein, it is desirable for the angle α to be four steps or more in terms of the variations in the reference position illustrated inFIG.4(variation in stable stop position of rotor21) and a hand movement operation to remove backlash for preventing the displacement between the stop position of the hand11after the normal rotation by the backlash and the stop position of the hand11after the reverse rotation by the backlash (hand movement operation which stops by normal rotation of two steps after reverse rotation of 12 steps when reverse rotation of 10 steps is set to target stop position, for example).

In addition, for example, it is preferable for the driving signal to be set to 12 degrees (=four steps) or more when the hand11moves by three degrees per one step.

FIG.6shows that the wheel121rotates in the clockwork direction from the state illustrated inFIG.5, and the hand11is aligned with the leading end edge of the fan-shaped display region41in the clockwise direction (rear end edge in counterclockwise direction).

When the angle from the leading end edge to the rear end edge of the fan-shaped display region41in the clockwise direction is set to β degree, the wheel121rotates at the angle of β degree in the clockwise direction from the position of the projection126illustrated inFIG.5to the position of the projection126illustrated inFIG.6. In addition, the angle β may be 120 degrees as an example, but it is not limited to 120 degrees.

By inputting a predetermined number of driving signals corresponding to the rotation angle of β degree of the hand driving wheel12into the stepping motor20, the hand11reaches the position in which the hand11is aligned with the leading end edge of the fan-shaped display region41in the clockwise direction as illustrated inFIG.6from the position in which the hand11is aligned with the rear end edge of the fan-shaped display region41in the clockwise direction as illustrated inFIG.5.

FIG.6shows that the pinion14bengages with the tooth122in the angle area123provided with the teeth122, and is rotatable both in the clockwise direction and the counterclockwise direction.

Between the state illustrated inFIG.5and the state illustrated inFIG.6, the hand11can reciprocate in the area of the fan-shaped display region41according to the rotation of the hand driving wheel12, and the hand11can perform predetermined display by indicating a scale displayed on the fan-shaped display region41.

FIG.7shows that the hand driving wheel12rotates at an angle of γ degree in the clockwise direction from the state illustrated inFIG.6such that the pinion14bengages with the rear end tooth122of the angle area123provided with the teeth122in the clockwise direction (leading end tooth in counterclockwise direction).FIG.7shows that the projection126of the wheel121starts contacting the arm portion13aof the kick spring13fixed to the movement.

By inputting a predetermined number of driving signals corresponding to the rotation angle of γ degree of the hand driving wheel12into the stepping motor20, the projection126of the wheel121reaches the position illustrated inFIG.7from the position illustrated inFIG.6. It is desirable for the number of the steps of the driving signal to be one step or more such that the wheel121receives a pressing force by the kick spring13and the stop position of the hand11is not affected by the backlash when the hand11locates within the fan-shaped display region41, due to the variations in the projection126and the kick spring13.

In addition, it is preferable for the driving signal to be set to three degrees (=one step) or more when the hand11moves by three degrees per one step.

The wheel121includes the angle area123provided with the teeth122and the region adjacent to the angle area123. A part of the region adjacent to the angle area123, which is adjacent to the rear end tooth122in the clockwise direction (leading end tooth in counterclockwise direction), is provided with the idle region124. Accordingly, the pinion14bcan further rotate in the counterclockwise direction from the state illustrated inFIG.7. In the state illustrated inFIG.7, the hand11dislocates from the fan-shaped display region41in the clockwise direction.

FIG.8shows that all of the teeth122of the angle area123are fed in the clockwise direction by the rotation of the pinion14bto be located beyond the pinion14bin the clockwise direction, and the hand driving wheel12rotates at an angle of δ degree in the clockwise direction from the state illustrated inFIG.7.

In the state illustrated inFIG.8, the pinion14bfeeds all of the teeth122in the clockwise direction, and the pinion14blocates in the idle region124. In the idle region124, although the tooth122contacts the pinion14b, the wheel121idles without rotating even when the pinion14brotates in the counterclockwise direction.

The rotation of the pinion14bin the counterclockwise direction corresponds to the rotation of the rotor21of the stepping motor20in the normal rotation direction (clockwise direction). Accordingly, by the idle of the pinion14bin the counterclockwise direction, the rotor21is rotatable without being inhibited from rotating in the normal rotation direction.

By the control of the controller, when a predetermined number of driving signals is input into the stepping motor20to locate the idle region124to the pinion14b, the rotation of the rotor21in the normal rotation direction stops.

In the state illustrated inFIG.8, as the intermediate wheel14does not further rotate the hand driving wheel12in the clockwise direction, the hand11fixed to the hand driving wheel12locates in the leading end edge of the rotatable area in the clockwise direction (rear end edge in the counterclockwise direction).

Moreover, in the state illustrated inFIG.8, as the wheel121rotates at the angle of δ degrees in the clockwise direction from the state illustrated inFIG.7, the projection126of the wheel121presses one of the arm portions13aof the kick spring13in the clockwise direction. The kick spring13thereby elastically deforms to narrow the angle interval between the two arm portions13a,13b.

As a result, the kick spring13presses the wheel121in the counterclockwise direction by pressing (biasing) the projection126provided in the wheel121in the left direction of the figure with the reaction force according to the elastic deformation. In the state illustrated inFIG.8, the wheel121rotates in the counterclockwise direction by the torque in the counterclockwise direction received from the kick spring13, and the teeth122of the wheel121press the pinion14b.

FIG.9shows that the wheel121slightly rotates in the counterclockwise direction by the torque in the counterclockwise direction received from the kick spring13, so that the tooth122of the wheel121engages with the pinion14bto be stopped.

As the rotation of the rotor21stops, the pinion14brotates in the clockwise direction by being pressed in the clockwise direction from the teeth122with the torque of the kick spring13. However, by the balancing between the retaining torque (cogging torque) which maintains the stop state of the rotor21coupled to the pinion14band the torque by the elastic force of the kick spring13, as illustrated inFIG.9, the pinion14bstops when the projection126returns in the counterclockwise direction at an angle of ε degree from the position of the projection126(illustrated by two-dot chain line) inFIG.8.

In order to definitely move the wheel121from the position illustrated inFIG.8to the position illustrated inFIG.7, in view of variations in components, it is preferable to set the specifications of the kick spring13and the hand driving wheel12such that the angle ε becomes smaller than the angle δ (ε<δ).

In the stopped state illustrated inFIG.9, the tooth122contacts the pinion14band the projection126contacts the arm portion13aof the kick spring13. However, in the states illustrated inFIGS.4to6, the projection126does not contact the kick spring13. Accordingly, in the states illustrated inFIGS.4to6, the torque in the counterclockwise direction by the kick spring13is not applied to the wheel121.

The operation of the fan-shaped display mechanism10and the timepiece100of the embodiment configured as described above will be described. More specifically, it will be described when a predetermined physical amount in the operation of the timepiece100is displayed on the fan-shaped display region41by the hand11.

In the timepiece100, by the operation of the controller of the timepiece100, the rotor21of the stepping motor20rotates in the counterclockwise direction, the wheel14aof the intermediate wheel14that engages with the wheel coaxial with the rotor21rotates in the clockwise direction, and the hand driving wheel12whose teeth122engage with the pinion14bof the intermediate wheel14rotates in the counterclockwise direction.

The pinion14bengages with the tooth122provided in the angle area123to rotate the hand driving wheel12in the counterclockwise direction. However, as illustrated inFIG.4, when the pinion14bcontacts the stopper129adjacent to the angle area123provided with the teeth122, the rotation of the pinion14bin the clockwise direction stops, and the pinion14bcannot further rotate the hand driving wheel12in the counterclockwise direction, so that the rotation of the hand driving wheel12stops. In this case, the rotation of the rotor21of the stepping motor20in the counterclockwise direction stops.

With the stopped position of the hand driving wheel12as the reference position (refer toFIG.4), a preset predetermined number of driving signals is input into the stepping motor20by the control of the controller to rotate the rotor21in the clockwise direction from the reference position, and to move the hand11in a position which is aligned with the rear end edge of the fan-shaped display region41in the clockwise direction (refer toFIG.5).

For example, it is preferable for the driving signal to be set to 12 degrees (=four steps) or more when the hand11moves three degrees per one step.

Herein, the rotation of the rotor21of the stepping motor20is switched to the rotation in the clockwise direction (normal rotation direction) from the reference position in which the rotation in the counterclockwise direction (reverse rotation direction) is stopped. However, when switching from the reverse rotation direction to the normal rotation direction, it is not necessary for the stepping motor20to slightly rotate in the reverse rotation direction prior to the rotation in the normal rotation direction.

Next, in order to move the hand11(FIG.5) in the position that is aligned with the rear end edge of the fan-shaped display region41in the clockwise direction to the position of a predetermined scale of the fan-shaped display region41corresponding to the physical amount to be displayed, the number of driving signals corresponding to the rotation angle of the hand driving wheel12to the position of the scale is input into the stepping motor20by the control of the controller.

The hand11thereby rotates in the clockwise direction from the position that is aligned with the rear end edge of the fan-shaped display region41in the clockwise direction, and stops in a position indicating a predetermined scale of the fan-shaped display region41, so that a predetermined physical amount is displayed by the scale indicated by the hand11.

In order to further rotate the hand11in the clockwise direction from this state, when the driving signal for normally rotating the rotor21is input into the stepping motor20, the hand driving wheel12rotates in the clockwise direction to the position in which the idle region124corresponds to the pinion14b, as illustrated inFIG.8, through the state illustrated inFIG.6and the state illustrated inFIG.7in this order.

When the hand driving wheel12rotates to the position in which the idle region124corresponds to the pinion14b, the pinion14bidles. The rotation of the rotor21in the normal rotation direction stops by the control of the controller when a predetermined number of driving signals is input into the stepping motor20.

In this case, as the hand driving wheel12does not further rotate in the clockwise direction, the hand11locates in the leading end of the rotatable area in the clockwise direction.

As the projection126provided in the wheel121of the hand driving wheel12receives the reaction force of the kick spring13elastically deformed by pressing the arm portion13afrom the state illustrated inFIG.7, the hand driving wheel12goes back in the counterclockwise direction to the position illustrated inFIG.9from the state illustrated inFIG.8, and stops.

In the state illustrated inFIG.9, the pinion14bstops while the pinion14bengages with the tooth122. However, when the rotor21rotates in the clockwise direction, and stops, it is necessary to rotate once the rotor21in the normal rotation direction prior to the rotation in the counterclockwise direction, in order to rotate the rotor21in the counterclockwise direction next.

In the fan-shaped display mechanism10of the present embodiment, as the pinion14blocates in the idle region124of the wheel121when the rotor21rotates in the clockwise direction, and stops, the pinion14bcan idle in the reverse rotation direction.

Accordingly, when the hand11rotates in the counterclockwise direction to return to the reference position, the rotor21once slightly rotates in the normal rotation direction, and then the rotor21can rotate in the counterclockwise direction with the reaction force that returns to the stopped position from the normal rotation direction.

The hand11stopped at the leading end edge (rotation of rotor21in normal rotation direction) of the rotatable area in the clockwise direction thereby directly rotates in the counterclockwise direction to indicate the scale provided in the fan-shaped display region41, so that the hand11that rotates in the counterclockwise direction can also display a predetermined physical amount.

The biasing direction of the kick spring13is a direction in which the tooth122adjacent to the idle region124engages with the pinion14bwhen the idle region124faces the pinion14bof the intermediate wheel14.

As described above, according to the fan-shaped display mechanism10and the timepiece100including the fan-shaped display mechanism10of the present embodiment, the hand11can reciprocate within a fixed area without providing an external operation member that is operated from an exterior.

The hand driving wheel12in the fan-shaped display mechanism10of the present embodiment includes the stopper129that prevents mechanical rotation in the counterclockwise direction at a predetermined angle or more. The positional relationship between the hand11attached to the wheel121and the position of the scale of the fan-shaped display region41can be thereby set with the position in which the pinion14bcontacts the stopper129to be mechanically stopped as the reference position.

Modified Example

In the fan-shaped display mechanism10and the timepiece100of the above-described embodiment, the hand driving wheel12and the kick spring13as an example of the biasing member are separated. However, the hand driving wheel12and the biasing member may be integrated.

FIGS.10,11show that a part of a wheel821of a hand driving mechanism82is formed as a circular arc shaped elastic portion83(example of biasing member) extending in a circumference direction of the wheel821.

Similar to the wheel121of the embodiment, the wheel821includes an angle area123provided with teeth122, an idle region124adjacent to the angle area123, and a stopper129.

The circular arc shaped elastic portion83has one end as a fixed end83bcoupled to the stopper129and the other end as a free end83ain front of the fixed end83bin the clockwise direction. The free end83aseparates from a main body of the wheel821(a part of wheel821except elastic portion83).

The free end83aof the wheel821configured as described above starts contacting an inclined wall95formed in, for example, a ground plane of a movement in the state illustrated inFIG.10, similar to the state illustrated inFIG.7in the embodiment.

Then, by the rotation of the pinion14bin the counterclockwise direction, the wheel821further rotates in the clockwise direction, so that the free end83amoves along the inclined wall95while contacting the inclined wall95, and the free end83athereby moves toward an inside of the wheel821in the radial direction, as illustrated inFIG.11. The elastic portion83bends with a curvature of the circular arc larger than that in the state in which the free end83adoes not contact the inclined wall95, similar to the state in which the fixed end83bis fixed.

Thereby, the wheel821receives the reaction force according to the bending of the elastic portion83from the fixed end83b, and this becomes a torque rotating in the counterclockwise direction. In addition,FIG.11corresponds to the state illustrated inFIG.8in the embodiment.

With the fan-shaped display mechanism in the modified example as configured above, the operations and effects similar to those in the embodiment can be obtained, and the number of components can be reduced by integrating the hand driving wheel and the biasing member.

In the fan-shaped display mechanisms10of the above-described embodiment and modified example, the elastic member is adopted as the biasing member, and the kick spring is adapted as the elastic member. However, the elastic member is not limited to the kick spring, and another spring such as a coil spring and a plate spring can be adopted, or a rubber or the like which is an elastic material can be adopted.

The biasing member is a member that biases in one direction, and is not limited to the elastic member that presses in a predetermined direction by an elastic force or biases by pulling, for example, and may be a member that biases by pressing and pulling in a predetermined direction with a load except an elastic material.

The fan-shaped display mechanisms10of the above embodiment and the modified example can reciprocate the hand11in a circular arc shape within the fan-shaped area (area larger than fan-shaped display region41from state illustrated inFIG.4to state illustrated inFIG.8) containing the fan-shaped display region41to display a predetermined physical amount. However, the reciprocating display mechanism of the present disclosure is not limited to the one that reciprocates the hand in a circular arc shape within the fan-shaped area.

Namely, the reciprocating display mechanism according to the present disclosure may be the one that linearly reciprocates the hand within a fixed rectangular area, or the one that reciprocates along a path of another shape.

In the fan-shaped display mechanisms10of the above-described embodiment and modified example, the area larger than the fan-shaped display region41is set as the “fixed area” within which the hand in the reciprocating display mechanism according to the present disclosure reciprocates. However, the fan-shaped display region41may be the “fixed area” in the present disclosure.

In the fan-shaped display mechanisms10of the above-described embodiment and modified example, the hand11and the hand driving wheel12are integrated. However, the hand11may be separated from the hand driving wheel12as long as it operates by the linkage with the movement of the hand driving wheel.