JP2005300282A - Analog chronograph timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a timepiece movement of an analog chronograph timepiece capable of fan-shaped display with a simple structure, while using in common a heart cam which is difficult to be processed. <P>SOLUTION: A restricting pin 16 is pressed and fixed in a gear train base 6, to thereby prevent the phase of the heart cam 4b from being deviated up to an irreversible domain. A projection part 8d is formed on the tip part of a return-to-zero lever 8 for zero-returning the heart cam 4b, to thereby acquire a structure wherein the heart cam 4b is reversely zero-returned without fail. Therefore, a structure can be acquired, wherein the heart cam 4b which is difficult to be processed is used in common, and the retrograde chronograph can be reversed simply and surely. In addition, the gear train base 6 is used in common with another product, thereby realizes common use of the component for products having a plurality of specifications to thereby reduce cost. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an analog chronograph timepiece structure using a heart cam.

  Conventionally, a timepiece has a display format of time, an analog display system that displays time by two or three hands, a digital display system that displays time by an electro-optical display device typified by liquid crystal or LED, It is known that the method can be roughly divided into a combination method in which the analog display method and the digital display method are combined. In addition, among analog timepieces, for example, the user has the presence or absence of a second hand or calendar, and the presence or absence of a subordinate timekeeping function represented by a timer function, a chronograph function, an alarm function, a moon age display function, etc. It is also known that you can choose according to your preference.

  Among these, analog display chronograph watches, so-called analog chronograph watches, are equipped with a small hand as a function hand in addition to the pointer to display the normal time, and start / interrupt time measurement by the user's push button operation In addition, the type that resets the measurement time is common, and it has a function and design that is slightly different from the so-called standard type clock in which the hour hand, minute hand, and second hand that display the normal time are arranged in the center of the dial. It is also known that many watches have been put to practical use due to differences in the smallest unit of the position, design, and measurement time of the small hands.

  These analog chronograph watches are roughly classified into a mechanical type that obtains a driving force by winding a mainspring and a quartz type that drives a motor by electrical energy such as a primary battery or a secondary battery. Things are also known.

  As for the so-called zero-return structure in which the measurement of the chronograph is completed and each chronograph hand is reset to the reference position, an input from an external operation member represented by a push button is mechanically transmitted using a lever and a heart cam. It can be broadly classified into a zero return structure for returning the pointer to an electric motor, or a null return structure for electrically returning the pointer by driving a motor using an electromagnetic switch.

  Furthermore, as a function of the difference in the position, design, and measurement time of the small hand, the so-called retrograde analog chronograph, in which the start time of the chronograph hand and the position of the maximum measurement time are not matched, and the measurement time is a fan-shaped display Watch. Other examples of watches with retrograde design include calendars and the remaining capacity display of mechanical watches in addition to the chronograph, which are realized in a great many products.

Satoshi Iwamoto et al., “Saray Mook Lapita, Adult Luxury Watch”, Shogakukan, December 2003, p. 42

Hereinafter, the structure of a timepiece movement of a conventional analog chronograph timepiece will be described with reference to the drawings. FIG. 9 is a plan view of a main part of a timepiece movement of a conventional analog chronograph timepiece as viewed from the back cover side. In FIG. 9, reference numeral 1 denotes a base material of the watch movement 100, and a base plate, 2a and 2b, which is a plate-like part that holds the components of the watch movement 100, such as a train wheel, a winding stem correction mechanism (not shown), and a motor. Is a push button that is a member that operates the watch, 3 is one revolution in 60 seconds, and displays a measurement time in units of 1 second, a second chronograph wheel that drives a second chronograph hand (not shown), 4 is a unit of 1 minute A minute chronograph wheel for driving a minute chronograph hand (not shown) for displaying a chronograph measurement time, 4a is a minute chronograph axle in which a minute chronograph hand is press-fitted and fixed, and 4b is press-fitted and fixed to a minute chronograph axle 4a. Heart cam,
Reference numeral 5 denotes a chronograph intermediate wheel that decelerates the rotation of the second chronograph wheel 3 and transmits a driving force to the minute chronograph wheel 4, and reference numeral 6 denotes a second chronograph wheel 3, minute chronograph wheel 4, and chronograph intermediate wheel 5. A train wheel bridge, which is a plate-like component that holds and holds a representative wheel train group for holding the pointer with the base plate 1, 7 is a circuit board on which an IC or a crystal unit (not shown) is mounted, 18 A zero return lever which regulates the movement of the chronograph wheel 4 and is operated by operating the push buttons 2a and 2b, and a hammer 9 which is a part for returning the minute chronograph wheel 4 by the movement of the push button 2b. Reference numeral 10 denotes a chronograph presser that is a plate-like component that holds a circuit support base (not shown) made of plastic that presses and holds the zero return lever 18, the hammer 9 and the circuit block 7 by sandwiching it with the base plate 1. That.

  The timepiece movement of the analog chronograph timepiece shown in FIG. 9 has, as its chronograph mechanism, a second chronograph hand at the center of the timepiece and a minute chronograph hand at the 10 o'clock position as viewed from the dial side to measure seconds and minutes. The time can be displayed with two different hands. Further, since the second chronograph wheel 3 is driven by a chronograph motor (not shown) and is connected to the minute chronograph wheel 4 through the chronograph intermediate wheel 5, the second measurement time and the minute measurement time of the chronograph are linked. It has a structure to do.

  The outline of the operation of the analog chronograph timepiece shown in FIG. 9 will be briefly described below.

  In FIG. 9, in a state where the chronograph measuring function is not operated, the zero return lever 18 is at a position 180, and the tip end portion 18a presses the heart cam 4b with a predetermined load with a predetermined deflection. Thus, the minute chronograph hand is fixed so as not to move in a state where the chronograph measuring function is not operated. Here, the chronograph presser 10 is integrally formed with a moderation portion 10c, and the moderation portion 10c applies a lateral pressure to the pin 18b press-fitted and fixed to the zero return lever 18 with a predetermined deflection. Is fixed at 180 position. Further, the hammer 9 is determined relative to the zero return lever 18 by a hammer pin 9a press-fitted and fixed to the lever body, and its position is 90. In this case, since there is a predetermined plane gap with the push button 2b, the chronograph does not operate at all even if the push button 2b is pressed.

  In FIG. 9, when the push button 2a is pressed, measurement with a chronograph is started. First, when the push button 2a is pushed, the push button 2a pushes the force point 18c of the zero return lever 18 through the contact spring portion 10a formed integrally with the chronograph presser 10. The nulling lever 18 rotates counterclockwise around the nulling lever shaft 1a press-fitted and fixed to the base plate 1 and moves to the position 181 so that the tip 18a releases the pressure on the heart cam 4b. To do. Further, the contact spring portion 10a is in contact with a side through hole 7a formed in the circuit board 7, so that a measurement start signal is input to an IC (not shown), and a motor (not shown) is driven. The chronograph wheel 3 and the minute chronograph wheel 4 are rotated, and measurement of the chronograph is started. The hammer 9 rotates around a hammer axis 1b that is press-fitted and fixed to the main plate 1. The hammer 9 is interlocked with the zero return lever 18 by the hammer pin 9a, and moves from the 90 position to the 91 position as the zero return lever moves from the 180 position to the 181 position. .

  Here, when the zero return lever 18 is moved from the position of 180 to the position of 181 by the operation of the push button 2a, it gets over the mountain shape of the moderation portion 10c. Due to this overriding operation, a predetermined moderation feeling is produced when the push button is pressed, and it plays a role of improving operability and preventing erroneous operation.

As described above, the chronograph measurement is started by the operation of each component. During the chronograph measurement, the second chronograph wheel 3 and the minute chronograph wheel 4 are components of a chronograph motor (not shown). It is held only by the holding torque of the rotor.

  Next, the nulling structure will be described. The hammer is at position 91 during chronograph measurement. First, when the push button 2b is pushed, the push button 2b pushes the force point 9b of the hammer 9 through the contact spring portion 10b formed integrally with the chronograph presser 10. The hammer 9 rotates counterclockwise about the hammer shaft 1b and moves from the 91 position to the 90 position. Since the zero return lever 18 is interlocked with the hammer 9 via the hammer pin 9a, as the hammer 9 moves from 91 to 90, the position from the position 181 to the position 180 is increased. Moving. While the zero return lever 18 is moving from the position 181 to the position 180, the heart cam 4b at an arbitrary position is pressed by the tip 18a depending on the measurement time, and the chronograph axle 4a is pressed and fixed to the heart cam 4b. Return to zero. Further, the contact spring 10b is in contact with a side through hole 7b formed in the circuit board 7 at the tip thereof, so that a reset signal to an IC (not shown) is inputted, and a motor (not shown) is driven to drive the second chronograph. The car 3 rotates and returns to the second position.

  Here, the direction in which the heart cam 4b returns to zero depends on which direction the heart cam 4b is pushed by the return lever 18. In the case of the example shown in FIG. 9, the minute chronograph wheel 4 is a 60-minute counter that makes a full revolution in 60 minutes. Therefore, when the rotation angle of the heart cam 4b is less than 180 ° as a guide, that is, the measurement time is from 0 to 30 minutes Returns to zero in the reverse direction. In addition, during the measurement time from 30 minutes to 60 minutes, it returns to zero in the normal rotation direction.

  The minute chronograph wheel 4 has a mechanism in which the minute chronograph gear 4c and the minute chronograph shaft 4a slip, and can arbitrarily change the phase of each other. Thereby, at the time of the zero return operation, the minute chronograph axle 4a is returned by the lever in conjunction with the movement of the engaged heart cam 4b, and the minute chronograph gear 4c is interlocked with the second chronograph wheel 3. The second chronograph wheel 3 and the minute chronograph wheel 4 can be separately returned to zero.

  Various specifications have been devised or put into practical use for such a chronograph null-zero structure using a heart cam, which is widely known.

Published Patent Publication No. 61-83992 (page 2-9, FIG. 5) Utility model No. 2605696 (Fig. 1)

  Here, when the timepiece movement of an analog chronograph timepiece having a retrograde fan-shaped design is manufactured by using a mechanical zero return structure using a heart cam, various problems arise.

  First of all, because of the nature of the product, it is also a design characterized by chronograph measurement that emphasizes the movement of these fan-shaped hands, and it is necessary to return the zero of the chronograph through the range of the fan-shaped. However, as described above, since the direction in which the heart cam returns from zero depends on which direction the zero cam is pushed from, the heart cam may return to zero during normal rotation depending on the position of the heart cam. . In this case, since the scale exists only in the operating range of the chronograph in terms of design, returning to zero in the direction without the scale significantly impairs the attractiveness of the product.

In addition, when using a long chronograph hand to emphasize the movement of the fan hand, if the chronograph hand is returned to zero in the forward rotation direction, it interferes with the second chronograph hand at the center and the hour / minute hand in the time system. Thus, there may be a case where it cannot physically return to zero.

  In order to prevent this and to always return to zero in the reverse rotation direction, that is, in the range where the fan-shaped cut portion is formed, for example, a structure in which the heart cam is asymmetrical left and right and is always zeroed by reverse rotation is also conceivable. However, when the heart cam has a left-right asymmetric shape, it is very difficult to manage the dimensions in processing. In addition, because it is a part that returns due to the impact of the lever, it uses materials such as special steel to prevent deformation due to the impact of the lever, such as quenching and tempering. It is a part that requires a lot of man-hours, and machining itself is difficult.

  Moreover, the maximum measurement time itself of the chronograph can be automatically stopped when the maximum measurement time elapses by a timer built in the circuit. However, as explained in FIG. 9, during measurement of the chronograph, the chronograph train wheel group is held only by the holding torque of the rotor that is a component of the chronograph motor, so that, for example, an impact is applied during measurement. When the impact force exceeds the holding torque, the chronograph wheel train may be displaced. As a result, if the heart cam shifts to a position where it cannot be reversed, as described above, it will return to zero during normal rotation, or the chronograph needle may interfere with the center needle depending on the length of the needle. Sometimes it stops.

  As described above, the conventional technique has a problem that it is difficult to manufacture a timepiece movement of an analog chronograph timepiece that can display a fan hand using an existing heart cam. An object of the present invention is to provide a timepiece movement of an analog chronograph timepiece capable of fan-shaped display with a simple structure while commonly using a difficult-to-work heart cam in order to eliminate the above-mentioned drawbacks.

    In order to achieve the above object, the gist of the present invention is that a train wheel to which a pointer for displaying a measurement time is engaged, a heart cam press-fitted and fixed to a part of the train wheel, and for returning the pointer to zero An analog chronograph having a nulling lever for giving a predetermined rotation to the heart cam and an external operation member for operating the nulling lever, wherein the position of the pointer at the start of measurement is different from the position of the pointer when the maximum measurement time has elapsed. In the graph timepiece, a restricting member having a heart cam rotation restricting portion for restricting a rotation angle of the heart cam is provided with the heart cam and a predetermined sectional clearance.

  As a result, when the pointer is in the position where the maximum measurement time has elapsed, even if the heart cam is about to rotate due to an impact such as dropping, the heart cam rotation restricting portion stops the rotation of the heart cam within the range where the rotation can be returned to the reverse ( Therefore, even if the phase of the chronograph hands, that is, the heart cam is shifted due to an impact or the like, it is possible to provide an analog chronograph timepiece with a retrograde tone display that can reliably return to zero.

  The angle difference between the position of the pointer at the start of measurement and the position of the pointer when the maximum measurement time has elapsed is 180 degrees or less.

  By setting the angle difference to 180 degrees or less, the heart cam stop range restricted by the heart cam rotation restricting portion can be set to about 180 degrees at the maximum, so that the phase of the chronograph hands, that is, the heart cam is shifted by an impact or the like. Even in the event of a crash, it can be reliably returned to zero.

  The heart cam rotation restricting portion is formed of a metal material.

Thereby, even if the heart cam rotates due to an impact such as dropping and the heart cam collides with the heart cam rotation restricting portion, the heart cam rotation restricting portion is formed of a metal material, so that deformation or breakage is not caused. It is possible to provide a retrograde analog chronograph watch that does not occur.

  Further, the restriction member is a train wheel bridge that holds the train wheel.

  Thereby, it is not necessary to add a special new part, and a special space is not required, and the heart cam rotation restricting part that restricts the heart cam with a part near the chronograph train can be configured.

  Further, the restriction member is a holding member constituting a resin-made timepiece movement adjacent to the heart cam.

  Thereby, it is not necessary to add a special new part, and a special space is not required, and the heart cam rotation restricting part that restricts the heart cam by a part in the vicinity of the chronograph wheel train can be configured.

  Further, the heart cam rotation restricting portion has a predetermined plane gap with the heart cam when the chronograph is stopped or when the maximum measurement time of the chronograph has elapsed.

  As a result, even if a machining error occurs in each part such as the heart cam rotation restricting portion and the heart cam, the plane gap can absorb the machining error of each part, so it is built in the circuit that drives the chronograph during normal operation of the chronograph With this timer, it is possible to provide an analog chronograph watch that can be stopped reliably.

  Further, a convex portion for restricting the rotation direction of the heart cam is provided at a tip of the zero return lever.

  As a result, the convex portion provided at the tip of the zero return lever can push the heart cam in one direction, and the heart cam can be reliably zeroed by reverse rotation.

  In addition, the vehicle in which the heart cam is press-fitted and fixed in the train wheel is a minute chronograph wheel that displays a minute measurement result.

  As a result, it is possible to provide an analog chronograph timepiece in which the chronograph portion is displayed in a retrograde manner.

  Further, the heart cam rotation restricting portion of the restricting member is configured as a separate part, and the heart cam rotation restricting portion is deleted, whereby the restricting member is added to a general analog chronograph timepiece that does not require restriction of the rotation angle of the heart cam. Is used as a common part.

  As a result, the train wheel itself can be diverted from other products and used in multiple specifications depending on whether or not there is a pin press-fitting process. These parts can be used in common.

  By the present invention, the most difficult heart cam of the analog chronograph movement uses the existing parts in common, but the needle position at the start of the chronograph and the needle position of the maximum measurement time are different, retrograde fan needle display In the product of the specification, it is possible to realize a structure that reliably reverses the chronograph needle by a simple method.

  Details of the present invention will be described below with reference to the drawings.

  1 to 6 are schematic views of an analog chronograph timepiece and its timepiece movement showing a first embodiment of the present invention, FIG. 1 is a plan view of the analog chronograph timepiece, and FIG. 2 is an analog chronograph of FIG. FIG. 3 is a plan view of the main part of the watch movement when the watch movement of the watch is viewed from the back cover side, showing a state in which the chronograph is not operating, and FIG. 3 is a sectional height around the minute chronograph wheel of FIG. 4 is a schematic partial cross-sectional view showing the relationship, FIG. 4 is a plan view of the main part of the timepiece movement showing the state in which the chronograph hands are operated up to the maximum measurement time in the timepiece movement of FIG. 2, and FIG. FIG. 6 is an enlarged view of the main part of the timepiece movement shown in FIGS. 2, 4 and 5. FIG. (A) shows a stopped state of the chronograph, (b) the state of the maximum measurement time of the chronograph, the (c) the state in which the chronograph overruns.

  As shown in FIG. 1, the analog chronograph timepiece of the present invention uses an analog type quartz chronograph movement with a calendar. In addition to hands indicating time such as hour hand, minute hand and second hand indicating normal time, The center chronograph has a second chronograph hand 3b capable of measuring time in units of one second and a minute chronograph hand 4d capable of measuring time up to 30 minutes at the 10 o'clock position. In this embodiment, the minute chronograph hand 4d can measure up to 30 minutes, and the display range thereof is as shown in FIG. 1 at the position of the minute chronograph hand 4d at the start of measurement and when the maximum measurement time has elapsed. The angle difference between the positions of the minute chronograph hands 4d is 180 degrees, and an example of a fan-shaped display range of 180 degrees is shown.

  The two hands at the center of the timepiece other than the second chronograph hand 3b are the hour and minute hands indicating the current time, and the small pointer at the 6 o'clock position is the small second hand indicating the current second by moving in units of 1 second, and the 2 o'clock position. The small pointer is a 24-hour hand for displaying the current time, but since it is not directly related to the present invention, a detailed description thereof will be omitted.

  1 and 2, reference numeral 1 denotes a base material of the timepiece movement 20, and a base plate, 2a, which is a plate-like part that holds components of the timepiece movement 20, such as a train wheel, a winding stem correction mechanism (not shown), and a motor. 2b is a push button that is a member for the user to operate the watch, 3 is a full rotation in 60 seconds, and a second chronograph wheel that drives a second chronograph hand 3b that displays a measurement time in units of 1 second, 4 is a unit of 1 minute The minute chronograph wheel for driving the minute chronograph hand 4d for displaying the measurement result of the chronograph measurement time within the fan-shaped display range, 4a is a minute chronograph axle for which the minute chronograph hand 4d is press-fitted and fixed, 4b is A heart cam press-fitted on the minute chronograph wheel shaft 4a of the minute chronograph wheel 4 which is a part of the train wheel for displaying the measurement time, 5 is used to decelerate the rotation of the second chronograph wheel 3 and distribute the driving force. A chronograph intermediate wheel for transmission to the ronograph wheel 4, 6 holds a wheel train group represented by a second chronograph wheel 3, a minute chronograph wheel 4, and a chronograph intermediate wheel 5 while sandwiching it from the main plate 1. It is a train wheel bridge which is a plate-like component.

  7 is a circuit board on which an unillustrated IC or a crystal resonator is mounted, 8 is a movement of the minute chronograph wheel 4, and a predetermined rotation is applied to the heart cam 4 b in order to return the minute chronograph hand 4 d to zero. Zero return levers, 2a and 2b are push buttons which are external operation members for operating the zero return lever, 9 is a hammer which is a component for returning the minute chronograph hand 4d by movement of the push button 2b, and 10 is a zero return. This is a chronograph presser that is a plate-like component that holds a circuit support (not shown) made of plastic that presses and holds the lever 8, hammer 9 and circuit block 7 by sandwiching it with the base plate 1. In addition, about the same component as FIG. 9, the same number is attached | subjected and the description is abbreviate | omitted.

  1 and 2, the second chronograph hand 3b is press-fitted and fixed to the second chronograph wheel 3, and is driven by a chronograph motor (not shown). The minute chronograph hand 4 d is press-fitted and fixed to the shaft 4 a of the minute chronograph wheel 4, and is interlocked with the second chronograph wheel 3 by the chronograph intermediate wheel 5. Thus, during chronograph measurement, the second chronograph hand 3b displays the measurement time in units of one second, the minute chronograph hand 4d displays the measurement time in one minute units, and both hands 3b and 4d move in conjunction with each other. Yes.

  The clock movement 20 of the analog chronograph timepiece according to the present embodiment has a timer for counting the chronograph measurement time in an IC (not shown), and is not shown when the maximum measurement time of 30 minutes has elapsed. Stop driving the chronograph motor. Thereby, the chronograph hands 3b and 4d are automatically stopped in 30 minutes.

  The heart cam 4b is press-fitted and fixed to the minute chronograph axle 4a, but the heart cam 4b itself has a shape capable of normal rotation, and is the same as the timepiece movement of the conventional analog chronograph timepiece shown in FIG. The parts are commonly used.

  In FIG. 2, unlike the conventional example shown in FIG. 9, a convex portion 8d for restricting the rotation direction of the heart cam 4b is provided at the tip 8a of the zero return lever 8. 2 is a view of the timepiece of FIG. 1 as viewed from the back cover side. Therefore, the minute chronograph wheel 4 is driven counterclockwise (counterclockwise) in FIG. 2, but the convex portion 8d of the zero return lever 8 is In other words, the heart cam 4b is held in a convex shape so as to be held in reverse.

  That is, when the maximum measurement time of 30 minutes elapses, the measurement of the chronograph is terminated by stopping the drive signal from the IC (not shown). In this case, the heart cam 4b is moved from the position shown in FIG. It has moved to a position rotated 180 ° from the position shown (position shown in FIG. 6B to position shown in FIG. 6A). Here, when the push button 2b is pushed to return to zero, the push button 2b pushes the force point 9b of the hammer 9 via the contact spring 10b. As a result, the hammer 9 rotates via the hammer shaft 1b, and the zero return lever 8 is rotated by the hammer lever 9a.

  At this time, the tip portion 8a of the zero return lever 8 pushes the heart cam 4b to zero the minute chronograph wheel 4, but if the tip portion 8a has a straight shape as in the conventional example shown in FIG. It is unclear from the left or right side of the apex of the heart cam 4b due to the effects of part machining accuracy, part position accuracy, etc., and the heart cam 4b may be returned to zero in the forward rotation direction. On the other hand, in the present invention, as shown in FIG. 4 (or FIG. 6B), the convex portion 8d formed at the tip 8a of the zero return lever 8 is in a direction that obstructs the forward zero return direction of the heart cam 4b. Because of the protrusion, the heart cam 4b can always be rotated clockwise as shown in FIG. 6B, that is, the pointer can be returned to the reverse rotation direction 40. As a result, the heart cam 4b can be reliably reversed and returned to zero.

In the analog ronograph timepiece of the present embodiment, basically, when the maximum measurement time is reached, the IC (not shown) stops the chronograph measurement by stopping the driving of the chronograph motor (not shown). During operation of the graph, as described above, the graph is held only by the holding torque of the rotor of the chronograph motor. Therefore, when a strong impact force greater than the holding torque of the rotor is applied due to an impact such as a drop during the operation of the chronograph, the pointer may be displaced. If the amount of displacement of the minute chronograph hand 4d exceeds the limit of the zero return lever 8 causing the heart cam 4b to reversely return to zero due to these extremely strong impacts, the convex portion 8d on the return zero lever 8 as described above. Even if formed, there is a risk that the heart cam 4b is pushed in the forward rotation direction and returned to zero. In the worst case, the heart cam 4b is pushed in the direction of the central axis of the minute chronograph wheel 4, and there is a risk that the heart cam 4b is locked on the spot without being able to return to zero or reverse. is there.

  On the other hand, in the present invention, as shown in FIG. 2 and FIG. 3, plate-like parts that pivotally support a train wheel group represented by the second chronograph wheel 3, the minute chronograph wheel 4, and the chronograph intermediate wheel 5. A hole 6a is formed in the train wheel bridge 6, and a restriction pin 16 having a heart cam rotation restricting portion 16b for restricting the rotation angle of the heart cam 4b is press-fitted and fixed in the hole 6a, and the wheel arranged with a predetermined sectional clearance with the heart cam 4b. It is characterized in that the train holder 6 is also used as a restricting member. The restriction pin 16 constituting the heart cam rotation restricting portion 16b is made of a metal material and has a stepped shape as shown in FIG. 3 and contributes to stabilization of the pushing operation.

  Further, as shown in FIG. 3, the heart cam rotation restricting portion 16b of the restricting pin 16 is arranged at a position overlapping the heart cam 4b in cross section. That is, even when an impact is applied and the heart cam 4b is deviated in the forward direction, the heart cam 4b can be prevented from shifting beyond the limit by restricting the heart cam 4b by the heart cam rotation restricting portion 16b and stopping it.

  Details thereof will be described below. As shown in FIG. 6 (a), when the chronograph is not operating, the outermost peripheral portion of the heart cam rotation restricting portion 16b that is press-fitted and fixed to the train wheel bridge 6 has the heart cam 4b and a predetermined plane gap 11a. A hole 6a is formed at a position to be secured, and the regulation pin 16 is press-fitted and fixed. Accordingly, since the plane gap 11a is secured, the heart cam 4b is always positioned by the initial deflection of the tip 8a of the zero return lever 8 because it is not affected by the restriction pin 16. Further, as shown in FIG. 6B, even when the chronograph stops after a lapse of the maximum measurement time after the chronograph measurement is started, a predetermined plane clearance is provided between the heart cam 4b and the heart cam rotation restricting portion 16b. 11b is secured.

  In this way, by ensuring the plane gaps 11a and 11b between the heart cam 4b and the heart cam rotation restricting portion 16b, the heart cam 4b is caused by machining errors of each component, shaft backlash of the train wheel bridge 6 and the minute chronograph axle 4a, or the like. Absorbs position error. That is, the heart cam rotation restricting portion 16b is an insurance meaning when the minute chronograph wheel 4 is displaced due to an impact or the like. When the normal chronograph is used, the position of the heart cam 4b is set by the return lever 8. It is desirable to decide.

  In principle, a structure in which the plane gaps 11a and 11b are not secured and a structure in which the heart cam 4b always contacts the heart cam rotation restricting portion 16b when the chronograph is operated are possible. However, even when using a normal chronograph that is not subject to sudden impact or the like, the heart cam 4b always collides with the heart cam rotation restricting portion 16b and stops during the zero return operation. Alternatively, there is a risk that the heart cam rotation restricting portion 16b is worn and the nulling operation becomes unstable. Further, when a large impact is received, there is a possibility that the heart cam rotation restricting portion 16b may come off from the train wheel bridge that is press-fitted and fixed.

  In addition, if the positional accuracy of the hole 6a of the train wheel bridge 6 and the accuracy of the diameter of the heart cam rotation restricting portion 16b are out of order, the heart cam 4b contacts the heart cam rotation restricting portion 16b before the maximum measurement time of the chronograph elapses. In some cases, no further measurement is possible. That is, in the example of this product, there is a possibility that the minute chronograph hand 4d may stop in the middle of the sector scale, for example, around 29 minutes before the maximum measurement time of 30 minutes elapses. There is also a possibility of inhibiting the basic function as. For these reasons, it is necessary to ensure the plane gaps 11a and 11b between the heart cam 4b and the heart cam rotation restricting portion 16b in consideration of absorption of processing errors and operational stability of each component.

Next, FIG. 5 and FIG. 6C schematically show the case where an impact is applied during the operation of the chronograph and the heart cam 4b is displaced in the forward rotation direction. In this case, since the minute chronograph wheel 4 is displaced in the forward rotation direction, the heart cam 4b press-fitted and fixed to the minute chronograph wheel shaft 4a is overrun in the forward rotation direction due to an impact, but the heart cam 4b is restricted here. It is restricted by the heart cam rotation restricting portion 16b of the pin 16 and prevents the chronograph wheel 4 from over-rotating further. As a result, the minute chronograph wheel 4 does not rotate any more and stops on the spot. When the push button 2b is pressed in this state, the zero return lever 8 is actuated via the hammer 9 and the heart cam 4b is returned to zero. Here, since the force is applied to the heart cam 4b in the reverse rotation direction 40 by the convex portion 8d at the tip of the zero return lever 8, the heart cam 4b can be reliably reverse zeroed.

  Even if the heart cam 4b rotates due to an impact such as dropping, and the heart cam 4b collides with the heart cam rotation restricting portion 16b, the heart cam rotation restricting portion 16b is formed of a metal material. And no damage will occur.

  In this embodiment, the angle difference between the position of the minute chronograph hand 4d at the start of measurement and the position of the minute chronograph hand 4d at the time of the maximum measurement time is 180 degrees, but if the angle difference is 180 degrees or less, the heart cam Since the stop range of the heart cam 4b restricted by the rotation restricting portion 16b can be set to about 180 degrees at the maximum, even if the phase of the minute chronograph hand 4d, that is, the heart cam 4b is shifted due to an impact or the like, the zero return lever 8 Since the heart cam 4b can be reliably zeroed in the reverse rotation direction 40 by the convex portion 8d at the tip, the angle difference is desirably 180 degrees or less.

  Actually, as long as the heart cam 4b itself has a shape capable of normal zero return, even if the convex portion 8d is formed at the tip of the zero return lever 8, there is a point at which the heart cam 4b returns by normal rotation instead of reverse rotation. . However, since the heart cam 4b is regulated by the heart cam rotation restricting portion 16b before the heart cam 4b rotates to the point at which it returns to zero by normal rotation, the product does not return to zero by normal rotation. The train wheel bridge 6 of this embodiment has a shape in which a hole 6a is added to the wheel train bridge 6 used in the timepiece movement of other analog chronograph timepieces.

  FIG. 7 is a plan view of the main part of a timepiece movement of another analog chronograph timepiece in common use with the train wheel bridge 6 of the timepiece movement of the analog chronograph timepiece according to the present invention as seen from the back cover side. Here, the train wheel bridge 6 is entirely different from the outer peripheral shape, including the position of the hole 6a of the train wheel 6 to be held, except that the restriction pin 16 having the heart cam rotation restricting portion 6b configured as a separate part is deleted from the hole 6a. It has a common shape. In the timepiece movement of FIG. 7, the maximum measurement time of the chronograph is 60 minutes, and the minute chronograph wheel 4 makes one round in 60 minutes. That is, like the conventional analog chronograph timepiece shown in FIG. 9, depending on the position of the heart cam 4b, the minute chronograph wheel 4 may return in a normal rotation, and the reference range is from 31 minutes to 59 minutes. It has become.

  Accordingly, since there is a case where the return is caused by normal rotation, the restriction pin 16 having the heart cam rotation restriction portion 6b is not arranged, but the parts of the train wheel bridge 6 itself can be used with the hole 6a. Yes, parts can be shared. This makes it possible to produce analog chronograph movements with multiple specifications with minimal initial investment, without having to create new molds or use non-common parts with or without punching holes 6a in a common mold. The effect is extremely large.

  Hereinafter, Example 2 of the present invention will be described in detail with reference to the drawings. FIG. 8 is a cross-sectional view of a main part around the minute chronograph wheel 4 of the timepiece movement 30 of the analog chronograph timepiece according to the second embodiment to which the present invention is applied.

  In FIG. 8, the heart cam 4 b is disposed at a position sandwiching the minute chronograph gear 4 c with respect to the train wheel bridge 6. In this case, it is impossible to add the restricting pin 16 constituting the heart cam rotation restricting portion 16b to the train wheel bridge 6 as in the first embodiment, but the holding member constituting the watch movement adjacent to the heart cam 4b. There is a feature that a restriction pin 16 constituting the heart cam rotation restricting portion 12a is press-fitted and fixed to a circuit support base 12 which is a resin molded part, and the circuit support base 12 is also used as a restriction member.

  Thereby, even if it is not the train wheel bridge 6, it becomes possible to arrange the heart cam rotation restricting portion 12a at a position overlapping the heart cam 4b in cross section, and the same effect as in the first embodiment can be obtained. The operation is the same as that in the first embodiment, and a detailed description of the operation is omitted.

  Here, since the circuit support base is formed by injection molding using a polymer resin, the heart cam rotation restricting portion 12 a can be formed as a shape integrated with the circuit support base 12. However, the heart cam rotation restricting portion 12a has a shape for preventing overrun of the heart cam 4b when it receives an impact during use, and may be broken or deformed by the impact. Therefore, the rotation restricting portion 16b is configured. The material of the restriction pin 16 is preferably a metal. That is, even when the restricting portion is formed of a polymer resin product as in the second embodiment, it can be said that it is safer in terms of impact resistance to have a structure in which another metal part is press-fitted and fixed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said content, For example, the maximum measurement time is 10 minutes, such as a product with a maximum measurement time of 45 minutes, such as a soccer timer, and a basketball timer. It can also be applied to products, and it can be said that its application range is extremely wide.

1 is a plan view of an analog chronograph timepiece showing a first embodiment of the present invention. FIG. 2 is a plan view of a main part of the timepiece movement when the timepiece movement of the analog chronograph timepiece of FIG. 1 is viewed from the back cover side. FIG. 3 is a schematic partial cross-sectional view showing a relationship in cross-sectional height around the minute-counting wheel of FIG. 2. FIG. 3 is a plan view of a main part of the timepiece movement showing a state in which the chronograph hands are operated up to a maximum measurement time in the timepiece movement of FIG. FIG. 3 is a plan view of a main part of the timepiece movement showing a state in which the chronograph hands are overrun due to an impact or the like in the timepiece movement of FIG. 2. FIG. 6 is an enlarged view of a main part of the timepiece movement shown in FIGS. 2, 4, and 5, where (a) is a stopped state of the chronograph, (b) is a state at the maximum measurement time of the chronograph, and (c) is a chronograph. Indicates an overrun state. It is the principal part top view which looked at the timepiece movement of the other analog chronograph timepiece which used the train wheel bridge 6 of the timepiece movement of the timepiece of the analog chronograph timepiece of this invention from the back cover side. It is principal part sectional drawing of the periphery of the minute chronograph wheel 4 of the timepiece movement 30 of the analog chronograph timepiece which shows 2nd embodiment to which this invention is applied. It is the principal part top view which looked at the timepiece movement of the conventional analog chronograph timepiece from the back cover side.

Explanation of symbols

1 Ground plate 1a Zero return lever shaft 1b Return lever shaft 2a Push button (2 o'clock position)
2b Push button (4 o'clock position)
3 second chronograph wheel 3a second chronograph hand 4 minute chronograph wheel 4a minute chronograph axle 4b heart cam 4c minute chronograph gear wheel 4d minute chronograph hand 5 chronograph intermediate wheel 6 wheel train receiver 6a wheel train receiving hole 7 circuit board 8 Zero return lever 8a Zero return lever tip 8b Zero return lever pin 8c Zero return lever force point 8d Zero return lever tip convex part 9 Return lever 9a Return lever pin 9b Return lever force point 10 Chronograph presser 10a Chronograph presser contact part 10b Chronograph Graph retainer contact portion 10c Chronograph presser moderation spring portion 11a Plane clearance when chronograph is stopped 11b Plane clearance when chronograph is operated 12 Circuit support 12a Heart cam rotation restricting portion 16 Restricting pin 16b Heart cam rotation restricting portion 18 Returning lever 18a Return Zero lever tip 18b Zero lever 18c Zero return lever force point 20 Clock movement 30 Clock movement 40 Reverse direction 90 Reversing lever position when chronograph is stopped 91 Zero return lever position when chronograph is operated 100 Clock movement 180 Zero return lever position when chronograph is stopped 181 Chrono Zero return lever position during graph operation

Claims (9)

A train wheel to which a pointer for displaying the measurement time is engaged, a heart cam press-fitted and fixed to a part of the train wheel, and a nulling lever for giving a predetermined rotation to the heart cam to nullify the pointer, In an analog chronograph timepiece having an external operation member for operating the return zero lever, wherein the position of the pointer at the start of measurement is different from the position of the pointer when the maximum measurement time has elapsed, a heart cam that regulates the rotation angle of the heart cam An analog chronograph timepiece characterized in that a regulating member having a rotation regulating portion is provided with the heart cam and a predetermined sectional clearance. 2. The analog chronograph timepiece according to claim 1, wherein an angle difference between the position of the pointer at the start of measurement and the position of the pointer when the maximum measurement time elapses is 180 degrees or less. The analog chronograph timepiece according to claim 1, wherein the heart cam rotation restricting portion is formed of a metal material. The analog chronograph timepiece according to any one of claims 1 to 3, wherein the restricting member is a train wheel bridge that holds the train wheel. The analog chronograph timepiece according to claim 4, wherein the regulating member is a holding member constituting a resin-made timepiece movement adjacent to the heart cam. 6. The analog according to claim 1, wherein the heart cam rotation restricting portion has a predetermined plane gap with the heart cam when the chronograph is stopped or when the maximum measurement time of the chronograph has elapsed. Chronograph clock. The analog chronograph timepiece according to any one of claims 1 to 6, wherein a convex portion for restricting a rotation direction of the heart cam is provided at a tip of the return zero lever. The analog chronograph according to any one of claims 1 to 7, wherein the vehicle in which the heart cam is press-fitted and fixed in the train wheel is a minute chronograph wheel for displaying a minute measurement result. clock. The heart cam rotation restricting portion of the restricting member is configured as a separate part, and the heart cam rotation restricting portion is deleted, so that the restriction member is commonly used in a general analog chronograph timepiece that does not require restriction of the rotation angle of the heart cam. 9. The analog chronograph timepiece according to claim 1, wherein the analog chronograph timepiece is used as a part.

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