JPS6027985Y2 - Clock pointer return mechanism - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of the pointer return mechanism of a timepiece, and is intended to prevent the pointer from jumping when the pointer returns to zero.

In recent years, analog display clocks have become more accurate, and the need for accurate time adjustment mechanisms has increased.

In time adjustment, zero adjustment of the pointer is effective as a means of accurately adjusting the standard time and the time displayed on the clock to match.

According to this method, the user can accurately adjust the time simply by performing a zero return operation at the same time as the time signal.

However, the conventional zero return mechanism has a problem in that the pointer jumps.

Pointer skipping is a phenomenon in which the pointer shifts slightly in the direction of rotation after the zero return operation, and this has been a problem, especially in step-movement watches, as it causes a misalignment between the pointer and the scale on the dial. be.

This pointer skipping phenomenon occurs when the rotational stress during the stopping operation after the rapid rotational action due to return to zero exceeds the bonding force between the pointer and the pointer pipe.

In devices in which the pointer and the pointer pipe are connected by press-fitting, this pointer skipping phenomenon is an unavoidable problem, and a solution has been desired.

The present invention solves the above-mentioned conventional problems, and its purpose is to prevent the pointer from jumping when returning to zero.

The present invention is a distant relative of the above object, and includes a pointer zero return mechanism equipped with a heart cam provided on the pointer shaft. A regulating body that presses and rotates the heart cam, an operating lever made of an elastic member that can rotate integrally with the rotating shaft, and a buffer made of an elastic member that is provided integrally with the operating lever and has a buffer protrusion protruding from the main plate side. a lever, an operating knob that is erected on the operating lever and can be operated externally, four parts provided on the upper surface of the base plate into which the buffer protrusion can be fitted, and a regulator that separates the regulating body from the heart cam when the buffer protrusion is removed from the recess. An elastic member.

Hereinafter, the present invention will be explained in detail based on preferred embodiments.

An embodiment of the invention is illustrated in FIGS. 1-3.

FIG. 1 shows a perspective view of a second hand zero return mechanism of a timepiece according to the present invention.

The second hand wheel 10 is coupled to the second hand shaft 12 so as to be able to slip and rotate, so that the zero rotation of the second hand shaft 12 does not affect other time display wheel trains.

The second hand shaft 12 is rotatably supported by the upper plate 2 and the middle plate 4, and although not shown, a second hand sword is press-fitted and fixed at the tip.

Further, a heart cam 14 is fixed to the second hand shaft 12.

The rotating shaft 24 is rotatably supported by the upper plate 2 and the middle plate 4, and a regulating body 20 is fixedly formed in the middle.

An operating lever 30 is fixedly formed on one end of the rotating shaft 24.

The operating lever 30 here corresponds to an elastically deformable member that connects the regulating body and the operating section according to the present invention, and can prevent the pointer from jumping by appropriately elastic deformation.

In order to perform this elastic deformation operation of the operating lever 30,
The lever 30 may be molded from a metal material or a synthetic resin material.

On the other hand, an operating knob 32 is formed on the operating lever 30, and this operating knob 32 protrudes from an oblong hole 8 provided in the dust cover 6, thereby allowing the user to perform a zero return operation.

In the second hand zero return mechanism of the embodiment of the present invention, the buffer lever 3
4. The structure of the protrusion 36 and the cylindrical protrusion 3 has the function of holding the second return to zero and the function of buffering the rotational stress of the regulating body 20.

The second zero holding function is to enable accurate time adjustment operations, and the buffer function serves to prevent the pointer from jumping under a certain range of conditions.

The buffer lever 34 is formed integrally with the operating lever 30, and has a buffer protrusion 36 formed at its extended end.

A cylindrical projection 3 is formed on the upper plate 2.

The coil spring 40 has one end locked to the upper plate 2 and the other end locked to the buffer lever 34, thereby applying a return force to the operating lever 30 after the zero return operation.

Next, the zero return operation of the present invention will be explained based on FIG. 1 and FIG. 2 as an explanatory diagram of the operation seen from the plane.

The second hand return to zero operation associated with time adjustment is performed by moving the ° operation lever 30 in the direction of arrow A.

In reality, the lever 30 can be moved by the user moving the operating knob 32 in the direction of arrow A.

The movement of this operation lever 30 is caused by moving the rotation shaft 24 by arrow B.
By rotating in the direction, the regulating body 20 presses and rotates the heart cam 14, thereby achieving proper zero return control of the second hand sword.

Figures 1 and 2 show the operating position during the zero return operation.9The position of the zero return configuration in normal hand operation is indicated by the two-dot chain line 14'.
, 20', 30', 32', 34', 36' and 40
’ is shown.

In the zero return operation of the embodiment of the present invention, the buffer protrusion 36 of the buffer lever 34 engages with the cylindrical protrusion 3 at the final stage of the zero return operation.

Specifically, as shown in the enlarged sectional view of FIG. 3, the buffer protrusion 36 first collides with the outer wall of the cylindrical protrusion 3, and then the protrusion 36 rides up the outer wall of the protrusion 3 and enters the cylinder. It is to intrude.

By this operation, the moving speed of the operating knob 32 itself is buffered at the final stage, so that the regulating body 20 can obtain the effect of buffering the pressing force on the heart cam 14, so that the heart cam 14 is at the zero rotation position. It is understood that the stop control can be performed smoothly.

This means that the stress of the stopping operation after the return rotation of the heart cam 14 is buffered and weakened.
The second hand skipping phenomenon can be prevented when the return-to-zero operation stress is below a certain range.

Thermal theory, the range of zero stress in which the second hand skipping phenomenon can be prevented is wider than that of a conventional zero return mechanism without a buffer mechanism, and this can be cited as a characteristic structure of the embodiment.

On the other hand, in the embodiment of the present invention, the buffer protrusion 3 of the buffer lever 34
6 fits into the cylindrical projection 3, a holding force at the zero operating position can be obtained.

This can provide a great feature regarding the simple and accurate time adjustment operation of the second hand sword.

This is because accurate time adjustment requires the clock side, minute hand side, and second hand blade to all match the standard time, and to do so, while holding the second hand blade in the zero position, adjust the timetable side while holding the second hand blade in the zero position. This is because it is desirable to correct.

The function of the operating lever 30 as a structure for preventing the pointer jumping phenomenon according to the present invention will be explained.

As mentioned above, the above-mentioned buffer mechanism prevents the pointer jumping phenomenon in a certain range of zero return stress, but this operating lever 30 is characterized in that this phenomenon is prevented no matter how large the return stress is.

The pointer jump phenomenon occurs when the pointer display shaft (or pipe) suddenly stops rotating due to its return to zero, and the stress generated by the rotation exceeds the bonding force between the pointer and the pointer display shaft. That's a problem.

The operation lever 30 according to the present invention fundamentally solves the pointer skipping phenomenon by preventing the pointer display shaft from suddenly stopping when returning to zero.

Specifically, if the rotation direction when the heart cam 14 is rotated by the regulating body 20 in FIG. 2 is x, then the heart cam 14 receives rotational stress in the x direction.

After the heart cam 14 has been rotated to the zero position (the position shown by the solid line) by the regulating body 20, this rotational stress can be adjusted to an appropriate level by rotating the heart cam 14 a little extra in the x direction (position 14'' in the figure). is attenuated by

This is because the buffer protrusion 36 of the buffer lever 34 rides up the cylindrical protrusion 3 during the final stage of movement of the operating knob 32, so that the moving speed of the operating knob 32 itself is buffered, and the elastically deformable operating lever 30 This is because the regulating body 20 can be slightly angularly moved (position 20'' in the figure) due to stress when the heart cam 14 returns to zero and stops.

When the heart cam 14 rotates from the position shown by the solid line to the position shown by 14'', the operating lever 30 is elastically deformed and the rotational stress is attenuated, and after once stopping, it rotates slightly in the direction of arrow Y. The vehicle will stop at the position shown by the solid line.

Therefore, the anti-coupling force generated between the second hand shaft 12 and the second hand side (not shown) is extremely small, and the needle skipping phenomenon, which has been a problem in the past, does not occur.

The zero reset operation can be performed by simply pushing the operating knob 32 in the direction of arrow C.

By doing so, the operating lever 30 is moved by the elastic member 40.
It returns to the normal state due to the elastic return force of.

As described above, the present invention integrally molds the regulating body, the operating lever, and the operating knob, so that the operating lever can be elastically deformed, and the buffer protrusion of the elastic buffer lever that is provided integrally with the operating lever elastically deforms the protrusion of the base plate. By making it possible to ride on the heart cam, it is possible to dampen the movement of the operating knob and gradually attenuate the inertial rotation of the heart cam by elastic deformation of the operating lever, thereby preventing the phenomenon of incorrect pointer jumping.

Furthermore, since the rotational force of the heart cam can be gradually attenuated only by the elastic force of the operating lever, there is no need to adjust the elastic forces of other elastic members and the operating lever.

Furthermore, since the number of parts is small, assembly is easy, and a watch pointer zeroing mechanism is provided which is an extremely practical device.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, and FIG. 1 is a perspective view of a second hand zero return mechanism of a watch. FIG. 2 is an explanatory diagram of the operation of the second hand zero return mechanism seen from a plane direction. FIG. 3 is an enlarged sectional view showing the operation of the buffer lever. 10... Second hand wheel, 12... Second hand shaft, 14... Heart cam, 20... Regulating body, 30... Operation lever 3
2... Operation knob, 3... Protrusion, 34... Buffer lever, 36... Buffer protrusion, 40... Elastic member.

Claims (1)

[Scope of utility model registration request] In a pointer zero return mechanism equipped with a heart cam provided on the pointer shaft, a rotating shaft rotatably supported on a base plate, a regulating body provided on the rotating shaft that contacts the heart cam and presses and rotates the heart cam, and a rotating shaft and An operating lever made of an elastic member that is rotatably provided; a buffer lever that is provided integrally with the operating lever and is made of an elastic member with a buffer protrusion protruding from the base plate side; a recess provided on the top surface of the base plate into which the buffer protrusion can fit, and an elastic member that separates the regulating body from the heart cam when the buffer protrusion is removed from the recess. Clock pointer return mechanism.