Patent Abstract:
A calendar timepiece has a main plate having a guide portion and a date indicator driving wheel mounted on the main plate to undergo rotation. A date feed finger is connected to the date indicator driving wheel for rotation therewith to engage the guide portion of the main plate so that the date feed finger is displaced in a generally thickness direction of the main plate. A date indicator has a tooth portion for meshing engagement with the date feed finger when the date feed finger engages the guide portion of the main plate and is displaced in the thickness direction of the main plate so that the date indicator undergoes rotation relative to the main plate to indicate date information during rotation of the date feed finger. A day feed finger is connected to the date indicator driving wheel for rotation therewith. A day indicator is connected to the day feed finger for rotation therewith to indicate a day of the week.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention: 
     The present invention relates to a timepiece having a calendar mechanism and, more particularly, to a timepiece having a small, thin calendar mechanism that prevents erroneous operation of a day indicator. 
     2. Description of the Prior Art: 
     Referring to FIG.  19  and FIG. 20, the conventional timepiece with calendar mechanism, e.g. a movement (mechanical body)  400  of an analog electronic timepiece, has a main plate  402  structuring a base plate of the movement  400 . A dial  404  (shown by the virtual line in FIG. 20) is attached on the movement  400 . 
     In the analog electronic timepiece, of the opposite sides of the main plate  402 , the side the dial  404  exists is referred to as a “back side” of the movement  400  and the side opposite to the side having the dial  404  is referred to as a “front side” of the movement  400 . The train wheel assembled on the “front side” of the movement  400  is referred to as a “front train wheel” and the train wheel assembled on the “back side” of the movement  400  is referred to as a “back train wheel”. 
     On the “front side” of the movement  400  are arranged a battery, a circuit block, a step motor, a front train wheel, a switch device (all not shown). By the rotation of the step motor, the front train wheel is rotated. 
     A center pipe  402   a  is provided on the main plate  402 . An hour wheel  410  is provided rotatable relative to the center pipe  402   a , and rotates twice per day due to rotation of the front train wheel. A date indicator driving wheel  412  is provided to rotate once per day due to rotation of the hour wheel  410 . 
     A date indicator  420  is provided rotatable relative to the main plate in order to indicate date. The date indicator  420  has a date-indicator teeth portion  422  having  31  teeth and a date plate  424  printed with characters to indicate date. A day indicator  430  is provided rotatable relative to the main plate to indicate day of the week. The day indicator  430  has a day star wheel  432  having 7 or 14 or 21 teeth and a day plate printed with characters to indicate day of the week. 
     The date indicator driving wheel  412  is provided with a date feed finger  414  capable of rotating the date indicator  420  by one day per day and a day feed finger  416  capable of rotating the day indicator  430  by one day per day. 
     The date feed finger  414  is structured integral with the date indicator driving wheel  412  through a date feed finger spring portion  414   b . The day feed finger  416  is structured integral with the date indicator driving wheel  412  through a day feed finger spring portion  416   b.    
     The date feed finger  414  is structured to rotate not to enter a rotation path of the day star wheel  432 . 
     However, in the conventional timepiece with calendar mechanism, unless the date feed finger is arranged not to enter a rotation path of the day star wheel, the date feed finger will mesh with the day star wheel resulting in a fear of erroneously operation of the day indicator. 
     Furthermore, in order to reduce the planar size of the timepiece with calendar mechanism while avoiding erroneous operation of the day indicator, there is a need to secure sufficiently great a gap in a thickness direction between the date feed finger and the day star wheel, which tends to increase the thickness of the timepiece. 
     SUMMARY OF THE INVENTION 
     Therefore, in order to solve the foregoing drawbacks in the conventional art, it is an object of the present invention to realize a small-and-thin type timepiece with a calendar mechanism that prevents erroneous operation of the day indicator. 
     Another object of the invention is to realize a timepiece with a calendar mechanism provided with such a date feed mechanism that the date feed finger can positively rotate the date indicator. 
     In order to solve the above problem, the present invention is, in a timepiece with calendar having a main plate structuring a base plate of a movement, a date indicator rotatably provided relative to the main plate to indicate date and having a date indicator teeth portion, a day indicator rotatably provided relative to the main plate to indicate day of the week and having a day star wheel, and a date indicator driving wheel rotating once per day to enable the date indicator to rotate by an amount of one day per day and the day indicator to rotate by an amount of one day per day, characterized in that: the date indicator driving wheel having a date feed finger capable of rotating the date indicator by an amount of one day per day and a day feed finger capable of rotating the day indicator by an amount of one day per day; the date feed finger being structured integral with the date indicator driving wheel through a date feed finger spring portion; the day feed finger being structured integral with the date indicator driving wheel through a day feed finger spring portion; the date feed finger being structured to rotate passing on main plate side of the day star wheel of the day indicator; wherein provided is a date feed finger guide portion to secure meshing in a thickness direction between the date feed finger and the date indicator teeth portion when the date feed finger meshes with the date indicator teeth portion. 
     Also, in the timepiece with calendar mechanism, the date feed finger guide portion is preferably provided on a back side of the main plate. 
     Also, in the timepiece with calendar mechanism, a slant surface is preferably provided in a portion that the date indicator driving wheel rotates and the date feed finger first contacts the date feed finger guide portion. 
     Also, in the timepiece with calendar mechanism, a semispherical convex portion is preferably provided in a portion that the date feed finger contacts the date feed finger guide portion. 
     Also, in the timepiece with calendar mechanism, the day feed finger is preferably structured to pass through on a dial side of the date indicator teeth portion, and the day feed finger being structured to rotate contacting the date feed finger guide portion in order to secure a gap in a thickness direction between the day feed finger and the date indicator teeth portion when the day feed finger rotates through the dial side of the date indicator teeth portion. 
     By the foregoing construction, in the timepiece with calendar mechanism, there is no fear of erroneous operation of the day indicator so that the date feed finger can positively rotate the date indicator. Further, by the foregoing construction it is possible to realize a small, thin timepiece with a calendar mechanism. 
     Also, in the timepiece with calendar mechanism, preferably provided in place of providing the date feed guide portion are a date feed finger guide groove portion to secure a mesh amount in a thickness direction between the date feed finger and a feed operating tooth portion when the date feed finger meshes with the feed operating tooth portion to be fed, an inner guide portion to prevent a decrease of the mesh amount between the date feed finger and the feed operating tooth portion and an outer guide portion to prevent an increase of the mesh amount between the date feed finger and the feed operating tooth portion. 
     By providing an inner guide portion, it is possible to effectively prevent a mesh amount between the date feed finger and the operating tooth portion from decreasing more than required. Also, by providing an outer guide portion, it is possible to effectively prevent a mesh amount between the date feed finger and the operating tooth portion from increasing more than required. Accordingly, by thus structuring, the date feed finger can positively rotate the date indicator. 
     Also, in the timepiece with calendar mechanism, preferably provided is a date feed forward gap secure portion to secure a gap in a planar direction between the date feed finger and a feed waiting tooth portion when the date feed finger rotates through a point near the feed waiting tooth portion to be next fed. 
     By the foregoing construction, it is possible to eliminate the fear that prior to date the date feed finger erroneously operates the date indicator. 
     Furthermore, in the timepiece with calendar mechanism, preferably provided is a date feed rear gap secure portion to secure a gap in a planar direction between the date feed finger and a feed end tooth portion when the date feed finger rotates through a point near the feed end tooth portion having been fed. 
     By the foregoing construction, it is possible to eliminate the fear that after date the date feed finger erroneously operates the date indicator. 
     Also, in the invention, preferably the timepiece with calendar mechanism is structured as an analog electronic timepiece, the timepiece with calendar mechanism having a quartz oscillator structuring source oscillation and a step motor to rotate the front train wheel, the step motor being structured to include a coil block, a stator and a rotor, and one part of the quartz oscillator and one part of the coil block being arranged to overlap with the date indicator. 
     By the foregoing construction, in the timepiece with calendar mechanism, because one part of the quartz oscillator, one part of the coil block and date indicator can be arranged compactly, a small, thin timepiece with a calendar mechanism can be realized. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred form of the present invention is illustrated in the accompanying drawings in which: 
     FIG.  1 . is a fragmentary sectional view showing an embodiment of a timepiece with calendar mechanism of the present invention; 
     FIG.  2 . is a schematic plan view as viewed from a side having a calendar mechanism in the embodiment of the timepiece with calendar mechanism of the invention (showing a state that a date indicator holder and day plate is removed); 
     FIG. 3 is a schematic plan view as viewed from a side having a front train wheel (side opposite to the side the calendar mechanism exists) in the embodiment of the timepiece with calendar mechanism of the invention (showing a state that a train wheel bridge, insulation plate and holder plate is removed); 
     FIG.  4 . is a fragmentary sectional view showing a quartz unit, date indicator driving wheel and coil block in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  5 . is a magnified fragmentary plan view showing a date indicator, date indicator driving wheel and day star wheel in a date feed state in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  6 . is a magnified fragmentary sectional view showing the date feed state of FIG. 5 in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  7 . is a magnified fragmentary plan view showing the date indicator, date indicator driving wheel and day star wheel in a day feed state in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  8 . is a magnified fragmentary sectional view showing the day feed state of FIG. 7 in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  9 . is a magnified fragmentary plan view showing a state a date feed finger positions beneath the day star wheel in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  10 . is a magnified fragmentary sectional view showing the state of FIG. 9 in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  11 . is a magnified fragmentary plan view showing a state in which a day feed finger rides on a main plate base in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  12 . is a magnified fragmentary sectional view showing the state of FIG. 11 in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  13 . is a magnified fragmentary plan view showing a part of the main plate positioned under the date indicator driving wheel and day star wheel in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  14 . is a magnified fragmentary plan view in the line A—A of FIG. 13 in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  15 . is a magnified fragmentary plan view showing a state in which the date feed finger positions near a tooth tip of the date indicator having been fed in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  16 . is a magnified fragmentary sectional view showing the state of FIG. 15 in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  17 . is a fragmentary sectional view showing a case in which the day feed finger does not ride on the main plate base in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  18 . is a fragmentary sectional view showing the case in which the day feed finger does not ride on the main plate base in the embodiment of the timepiece with calendar mechanism of the invention; 
     FIG.  19 . is a magnified fragmentary plan view showing a date indicator, date indicator driving wheel and day star wheel in the conventional timepiece with calendar mechanism; and 
     FIG.  20 . is a magnified fragmentary sectional view of the part shown in FIG. 19 in the conventional timepiece with calendar mechanism. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereunder, an embodiment of a timepiece with calendar mechanism of the present invention will be explained based on the drawings. 
     Although the explanation below is on a structure in which the timepiece with calendar mechanism of the invention is applied to an analog electronic timepiece, the invention is to be applied also to a mechanical timepiece besides the analog electronic timepiece. That is, the concept of “timepiece with calendar mechanism” in the present specification is a concept including “analog electronic timepieces”, “mechanical timepieces” and analog timepieces on all other operation principles. 
     Referring to FIGS. 1-4, a movement (mechanical body)  100  of the timepiece with calendar mechanism of the invention has a main plate  102  defining a base plate for the movement  100 . A dial  104  (shown by the virtual line in FIG. 1) is mounted on the movement  100 . 
     On a “front side” of the movement  100  are arranged a battery  120 , a circuit block  116 , a step motor, a front wheel train, a change-over device (not shown) and so on. The front wheel train rotates due to rotation of the step motor. An IC  118  and a quartz oscillator  122  are attached on the circuit block  116 . The battery  120  constitutes a power source for the timepiece with calendar mechanism. The quartz oscillator  122  constitutes source oscillation for the timepiece with calendar mechanism and oscillates, for example, at 372 or 768 Hertz. 
     The front wheel train is rotatably supported by the main plate  102  and wheel train bridge  112 . A circuit holding plate  114  is provided in a manner holding the circuit block  116  to the train wheel bridge  112 . A battery minus terminal  126  is held to the wheel train bridge  112 . An insulation plate  128  is arranged between the battery minus terminal  126  and the holding plate  114 . 
     The IC  118  includes an oscillator section, a frequency-divider section and a driver section. The oscillator section outputs a reference signal based on oscillation by the quartz oscillator  122 . The frequency-divider section divides an output signal of the oscillator section. The driver section outputs a motor drive signal to drive the step motor based on the output signal of the frequency-divider section. 
     The step motor includes a coil block  130 , a stator  132  and a rotor  134 . When the coil block  130  inputs a motor drive signal, the stator  132  is magnetized to rotate the rotor  134 . The rotor  134  is structured, for example, to rotate 180 degrees per second. 
     Based on rotation of the rotor  134 , a fourth wheel and pinion  142  is structurally rotates through rotation of the fifth wheel and pinion  140 . The fourth wheel and pinion  142  is structured to rotate once per minute. A second hand  144  is attached on the fourth wheel and pinion  142 . The fourth wheel and pinion  142  may be arranged at a center of the timepiece or in a position other than the timepiece center. 
     A wheel train setting lever  170  is provided to be allowed to rotationally operated when drawing out a hand setting stem  110  to a second stage and regulates the position of the fourth wheel and pinion  142 . 
     A third wheel and pinion  150  is structured to rotate based on rotation of the fourth wheel and pinion  142 . A second wheel and pinion  152  is structured to rotate based on rotation of the third wheel and pinion  150 . A minute wheel may be used in place of the center wheel and pinion  152 . A minute hand  164  is attached on the second wheel and pinion  152 . A slip mechanism is provided on the center wheel and pinion  152 . When adjusting the hands by the slip mechanism, the minute hand  154  and an hour hand can be rotated by rotating the hand setting stem  110  while the second hand  144  is stopped. The second wheel and pinion  152  is structured to rotate once per hour. 
     A minute wheel  174  is structured to rotate based on rotation of the second wheel and pinion  152 . A setting wheel  172  is provided which rotates through rotation of a clutch wheel (not shown) when the hand setting stem  110  is drawn to the second stage. When the hand setting stem  110  is drawn to the second stage, structure is made to rotate through rotation of the minute wheel  174  and clutch wheel (not shown). 
     A center pipe  102   a  is provided on the main plate  102 . An hour wheel  160  is rotatably provided on the center pipe  102   a . The hour wheel  160  is structured to rotate once per 12 hours. An hour hand  166  is attached on the hour wheel  160 . 
     By rotating a date indicator driving pinion (not shown) of the hour wheel  160 , a date indicator driving wheel  212  is structurally rotated. The date indicator driving wheel  212  is provided to rotate once per day due to rotation of the hour wheel  160 . 
     A date indicator  220  is provided rotatable relative to the main plate  102  in order to indicate date. The date indicator  220  has a date indicator teeth portion  222  having  31  teeth and a date plate  224  printed with characters to indicate date. A date indicator holder  228  rotatably holds the date indicator  220  relative to the main plate  102 . 
     A day indicator  230  is rotatably provided relative to the main plate  102  in order to indicate day of the week. The day indicator  230  has a day star wheel  232  having 14 teeth and a day plate  234  printed with characters to indicate day of the week. 
     The rotation of the date indicator  220  is regulated by a date jumper  240 . The rotation of the day indicator  230  is regulated by a day jumper  242 . The day jumper  242  is integrally formed with the date indicator holder  228 . 
     A first calendar correction wheel  280  is provided to rotate through rotation of the clutch wheel (not shown) when the hand setting stem  110  is with drawn to a first stage. A second calendar correction wheel  282  is provided to rotate through rotation of the clutch wheel and first calendar correction wheel  280  when the hand setting stem  110  is withdrawn to the first stage. A calendar correction wheel  284  is provided to rotate through rotation of the clutch wheel, first calendar correction wheel  280  and second calendar correction wheel  282  when the hand setting stem  110  is withdrawn to the first stage. The calendar correction wheel  284  is structured to swing only a constant angle about a rotation center of the second calendar correction wheel  282 . A day correction transmission wheel  286  is arranged to rotate the day star wheel  232  by the rotation thereof. 
     When the hand setting stem  110  is withdrawn to the first stage, if the hand setting stem  110  is rotated in a first direction, the calendar correction wheel  284  structurally swings in the first direction and rotates at a constant position to enable the date indicator  220  to rotate. When the hand setting stem  110  is withdrawn to the first stage, if the hand setting stem  110  is rotated in a second direction (direction opposite to the first direction), the calendar correction wheel  284  is structurally swings in the second direction (direction opposite to the first direction) and rotates at a constant position to enable the day correction transmitting wheel  286  to rotate. By rotating the day correction transmitting wheel  286 , the day star wheel  232  can be structurally rotated. 
     Referring to FIG. 4, a part of a quartz oscillator  122  and a part of the coil block  130  arranged on the “front side” are arranged in a manner overlapping the date indicator  220  arranged on a “back side” of the movement  100 . 
     Referring to FIG.  5  and FIG. 6, date indicator teeth  222  includes a feed operation tooth portion  222   b  now to be fed, a feed-waiting tooth portion  222   a  next to be fed, and a fed tooth portion  222   c  having already fed. A date indicator driving wheel  212  has a date feed finger  214  capable of rotating the date indicator  220  by an amount of one day per day and a day feed finger  216  capable of rotating the day indicator  230  by an amount of one day per day. 
     The date feed finger  214  is structured to be integral with the date indicator driving wheel  212  through a date feed finger spring portion  214   b . The day feed finger  216  is structured to be integral with the date indicator driving wheel  212  through a day feed finger spring portion  216   e.    
     A semispherical date feed finger convex portion is provided on the back side (main plate side) of the intersection of the date feed finger  214  and the date feed finger spring portion  214   b.    
     Referring to FIG.  13  and FIG. 14, a guide member or date feed finger guide portion  102   c  is provided on a back side (on a dial side) of the main plate  102  to secure an amount of meshing in a thickness direction of the main plate  102  between the date feed finger  214  and the feed operating tooth portion  222   b  when the date feed finger  214  meshes with the feed operating tooth portion  222   b . Thus the date feed finger guide portion  102   c  constitutes displacing means for displacing the data feed finger  214  in the thickness direction of the main plate  102  to secure meshing engagement between the feed finger  214  and the feed operating tooth portion  222   b . A slant surface  102   d  is provided in an area that a date feed finger convex portion  214   c  of the date feed finger  214  first contacts the date feed finger guide portion  102   c  due to rotation of the date indicator  212 . A slant surface  102   f  is provided in an area that the date feed finger convex portion  214   c  leaves the date feed finger guide portion  102   c . In an area where the date feed finger guide portion  102   c  is not present, a date feed finger escape groove  102   g  is provided on the back side (on the dial side) of the main plate  102 . The date feed finger convex portion  214   c  is structured to rotate facing the date feed finger escape groove portion  102   g  without contacting the date feed finger escape groove portion  102   g . 
     Where teeth count of the day star wheel  232  is fourteen, the day feed finger  216  is structured to feed the day star wheel  232  by two teeth per day. A first day feed portion  216   a  and a second day feed portion  216   b  are structured to respectively feed teeth portions of the day star wheel  232  by one tooth in one time. 
     The day feed finger  216  and the first day feed portion  216   a  have an intersection portion on the back side of which is provided a semispherical first day feed finger convex portion  216   c . The day feed finger  216  and the second day feed portion  216   b  have an intersection portion on the back side of which (on the main plate side) is provided a semispherical second day feed finger convex portion  216   d.    
     Although the teeth count in the teeth portion of the day star wheel  232  was explained as fourteen in the embodiment of the invention shown in FIG.  5  and FIG. 6, the teeth count of the day star wheel  232  may be seven or may be twenty-one. Where the teeth count of the day star wheel  232  is seven, the day feed finger  216  is structured to feed the day star wheel  232  by one tooth per day. Where the teeth count of the day star wheel  232  is twenty-one, the day feed finger  216  is structured to feed the day star wheel  232  by three teeth per day. 
     Meanwhile, the first day feed portion  216   a  and second day feed portion  216   b  provided on the tip of the day feed finger  216  were explained as the respective structures to feed the teeth portion of the day star wheel  232  by one tooth per time. However, the structure may be made such that the one day feed portion provided at the tip of the day feed finger  216  feeds the teeth portion of the day star wheel  232  by two teeth. 
     Referring to FIG.  5  and FIG. 6, in the embodiment of the timepiece with calendar mechanism of the invention, the date feed finger convex portion  214   c  of the date feed finger  214  in a date feed state first contacts a slant surface  102   d . By providing the slant surface  102   d , the date feed finger  214  smoothly operates to move over the date feed finger guide portion  102   c . Next, the date feed finger convex portion  214   c  of the date feed finger  214  operates over the date feed finger guide portion  102   c  of the main plate  102 . By operation of the date feed finger convex portion  214   c  over the date feed finger guide portion  102   c , it is possible to secure meshing in a thickness direction between the date feed finger  214  and the date indicator tooth portion when the date feed finger  214  meshes with the feed operation tooth portion  222   b  of the date indicator  220 . 
     The date feed finger convex portion  214   c  of the date feed finger  214  operates contacting the slant surface  102   f  thus leaving from the date feed guide portion  102   c . By this structure, it is possible to positively feed the date indicator  220  while smoothly rotating the date feed finger  214 . 
     Referring to FIG.  7  and FIG. 8, in the embodiment of the timepiece with calendar mechanism of the invention, in a day feed state the first day feed portion  216   a  and the second feed portion  216   b  provided at the tip of the day feed finger  216  respectively feed one tooth of the teeth portion of the day star wheel  232  in one time. In the day feed state, the first day feed finger convex portion  216   c  and second day feed finger convex portion  216   d  face the date feed finger escape groove portion  102   g  and rotate without contact with the date feed finger escape groove portion  102   g . Consequently, by this structure, the first day feed portion  216   a  operates without contacting the main plate  102  and also the second day feed portion  216   b  operates without contacting the main plate  102 . 
     Referring to FIG.  9  and FIG. 10, in the embodiment of the timepiece with calendar mechanism of the invention, in a state that the date feed finger  214  positions beneath the day star wheel  232 , the date feed finger  214  rotates between the day star wheel  232  and the main plate  102 . That is, the date feed finger  214  rotates passing through the main plate  102  side of the day star wheel  232  of a day indicator  230 . In this state, the date feed finger convex portion  214   c  is facing the date feed finger escape groove portion  102   g  and rotates without contacting the date feed finger escape groove portion  102   g . Consequently, due to this structure, the date feed finger convex portion  214   c  of the date feed finger  214  operates without contacting the main plate  102 . 
     Referring to FIG.  11  and FIG. 12, in a state that the day feed finger  216  is close to the feed operating tooth portion  222   b  of the date indicator  220 , the first day feed finger convex portion  216   c  and second day feed finger convex portion  216   d  of the day feed finger  216  operate riding on the date feed finger guide portion  102   c  of the main plate  102 . That is, the first day feed finger convex portion  216   c  and second day feed finger convex portion  216   d  firstly contact the slant surface  102   d . Next, the first day feed finger convex portion  216   c  and second day feed finger convex portion  216   d  operate over the date feed finger guide portion  102   c  of the main plate  102 . Then, the first day feed finger convex portion  216   c  and second day feed finger convex portion  216   d  operate contacting the slant surface  102   f , leaving from the date feed finger guide portion  102   c . That is, the tip of the first day feed portion  216   a  and the tip of the second day feed portion  216   b  rotate between the date indicator  220  and the day plate  314 . Due to this structure, the day feed finger  216  can be avoided from contacting the date indicator  220  while smoothly rotating the day feed finger  216 . 
     Next, explanation will be made on another embodiment of a timepiece with calendar mechanism of the invention. 
     Referring to FIG.  15  and FIG. 16, in another embodiment of a timepiece with calendar mechanism of the invention, a date feed finger guide groove portion  102   m  is provided on the back side (on the dial side) of the main plate  102  to secure a meshing amount in a thickness direction between the date feed finger  214  and the feed operating tooth portion  222   b  when the date feed finger  214  meshes with the feed operating tooth portion  222   b.    
     An inner guide portion  102   k  is provided on the back side (on the dial side) of the main plate  102  to prevent against decrease in meshing amount between the date feed finger  214  and the feed operating tooth portion  222   b  when the date feed finger meshes with the feed operating tooth portion  222   b . An outer guide portion  102   j  is provided on the back side (on the dial side) of the main plate  102  to prevent against increase in meshing amount between the date feed finger  214  and the feed operating tooth portion  222   b  when the date feed finger meshes with the feed operating tooth portion  222   b . Consequently, the date feed finger guide groove portion  102   m  positions between the outer guide portion  102   j  and the inner guide portion  102   k . The date feed finger convex portion  214   c  operates in the date feed finger guide groove portion  102   m  between the outer guide portion  102   j  and the inner guide portion  102   k.    
     By providing the inner guide portion  102   k , it is possible to effectively prevent the mesh amount between the date feed finger  214  and the feed operating tooth portion  222   b  from decreasing more than required. That is, the inner guide portion  102   k  can prevent the date feed finger  214  from disengages from the feed operating tooth portion  222   b  during date feeding. 
     Also, by providing the outer guide portion  102   j , it is possible to effectively prevent the mesh amount between the date feed finger  214  and the feed operating tooth portion  222   b  from increasing more than required. That is, the outer guide portion  102   j  can prevent the date feed finger  214  from caving in the feed operating tooth portion  222   b  during date feeding. 
     Accordingly, by this structure, the date feed finger  214  can positively rotate the date indicator  220 . 
     Furthermore, it is preferred to provide a slant surface in a location that the date indicator driving wheel  212  rotates and the date feed finger convex portion  214   c  first contacts the date feed finger guide groove portion  102   m . Also, it is also preferred to provide a slant surface in a location that the date feed finger convex portion  214   c  leaves from the date feed finger guide groove portion  102   m . Also, in a position that the date feed finger guide groove portion  102   m  is absent, the date feed finger escape groove portion  102   g  is provided on the back side (on the dial side) of the main plate  102 . That is, the date feed finger convex portion  214   c  is structured to rotate in the date feed finger guide groove portion  102   m.    
     In addition, a date feed forward gap secure portion  102   p  is provided on the back side (on the dial side) of the main plate  102  to secure a clearance in a planar direction between the date feed finger  214  and the feed-waiting teeth portion  222   a  when the date feed finger  214  rotates near the feed-waiting teeth portion  222   a . The date feed forward gap secure portion  102   p  is formed in a convex shape from the outer guide portion  102   j  toward the inner side and in a form of providing the entire with smoothness in order to keep the date feed finger  214  away from the feed-waiting teeth portion  222   a . By this structure, there is no fear that the date feed finger  214  contacts the feed-waiting tooth portion  222   a.    
     In addition, a date feed rear gap secure portion  102   n  is provided on the back side (on the dial side) of the main plate  102  to secure a clearance in the planar direction between the date feed finger  214  and the feed-waiting teeth portion  222   c  when the date feed finger  214  rotates near the feed-end teeth portion  222   c . The date feed rear gap secure portion  102   n  is formed in a convex shape from the outer guide portion  102   j  toward the inner side and in a form of providing the entire with smoothness in order to keep the date feed finger  214  away from the feed-end teeth portion  222   c . By this structure, there is no fear that the date feed finger  214  contacts the feed-end tooth portion  222   c . 
     In a date feed state, the date feed finger portion  214   c  of the date feed finger  214  first contacts the slant surface. Next, the date feed finger convex portion  214   c  of the date feed finger  214  rotates in the date feed finger guide groove portion  102   m  of the main plate  102 . By the operation of the date feed finger convex portion  214   c  in the date feed finger guide groove portion  102   m , when the date feed finger meshes with the feed operating teeth portion  222   b  of the date indicator  220 , it is possible to secure a meshing amount in a thickness direction between the date feed finger  214  and the feed operating teeth portion  222   b . At the same time, it is possible to keep within a constant range the meshing amount in the planar direction between the date feed finger  214  and the date indicator teeth portion. 
     Next, the date feed finger convex portion  214   c  of the date feed finger  214  rotates contacting the date feed finger clearance securing portion  102   n  of the main plate  102 . Then, the date feed finger convex portion  214   c  of the date feed finger  214  operates contacting the slant surface, leaving from the date feed finger guide groove portion  102   m.    
     Next, explanation will be made on still another embodiment of a timepiece with calendar mechanism of the invention. 
     Referring to FIG.  17  and FIG. 18, in still another embodiment of a timepiece with calendar mechanism of the invention, the semispherical first day feed finger convex portion  216   c  is absent in the backside (on the main plate side) of the intersection between the day feed finger  216  and the first day feed portion  216   a.    
     In this embodiment, by providing great a gap between the date indicator teeth portion  222  of the date indicator  220  and the day plate  234 , the tip of the first day feed portion  216   a  and the tip of the second day feed portion  216   b  are structured to rotate between the date indicator  220  and the day plate  234 . 
     Although the embodiments explained above explained the timepiece with a second hand, the structure of the invention is applicable to a timepiece without having a second hand. 
     The present invention, by being structured as explained above, can realize a timepiece with calendar mechanism free from fear of erroneous operation in the day indicator and has a date feed finger capable of positively rotating the date indicator. 
     Furthermore, the present invention can realize a timepiece with calendar mechanism small in size and thickness.

Technology Classification (CPC): 6