Abstract:
A portable timepiece has a timepiece movement disposed in a case band. A pipe extends through and is attached to the case band and has a male screw portion on a part of the pipe that extends outside the case band. A crown has a crown head and a crown shaft, and the crown head has a female screw portion threadedly engaged with the male screw portion and disengageable therefrom in response to rotation of the crown head in a loosening direction accompanied by axial movement of the crown head in a direction away from the case band. The crown shaft has one end portion that extends into the pipe and is connected to a hand setting stem of the timepiece movement and another end portion that extends outside the case band beyond the pipe and slidably contacts an inner peripheral surface of the crown head to support the crown head and guide the axial movement thereof. The crown shaft has a force receiving portion for receiving a rotational force to rotate the hand setting stem, and the crown head has a force transmitting portion that releasably engages with the force receiving portion during axial movement of the crown head away from the case band to enable a rotational force to be transmitted to the force receiving portion by rotating the crown head. The end portion of the crown shaft that slidably contacts the inner peripheral surface of the crown head constitutes the force receiving portion of the crown shaft.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a portable timepiece in which a crown is held so as not to be carelessly rotated by utilizing mesh of screws and a method of fabricating a crown provided to the timepiece. 
     2. Description of the Related Art 
     In a background art, there is a portable timepiece including a screw lock structure for holding a crown so as not to be rotated carelessly by utilizing mesh of screws. According to the screw lock structure, the crown includes a crown shaft for cooperatively moving a hand setting stem and a crown head for rotating the shaft. Further, a shaft end portion of the crown shaft is arranged at outside of a pipe having a male screw portion and fixed to a case band. Along therewith, a peripheral portion of the shaft end portion is formed with a rotational force receiving portion of a deformed shape and the crown head is provided with a female screw portion and a rotational force transmitting portion of a deformed shape. 
     The rotational force transmitting portion is provided with a diameter larger than that of the female screw portion and is formed continuously to the female screw portion. Therefore, from a necessity of working the rotational force transmitting portion, the crown head is formed by a head main body one end directed to a side of the case band of which is opened, and a cap constituting a part separate from the head main body, and the cap is mounted to close other end of the head main body. 
     According to the timepiece, the female screw portion is attachably and detachably brought in mesh with a male screw portion and the crown can be held so as not to be rotated carelessly by a mesh thereof. The rotational force transmitting portion is attachable and detachable to and from the rotational force receiving portion. That is, in the screw lock state in which the female screw portion is brought in mesh with the male screw portion, the rotational force transmitting portion is separated from the rotational force receiving portion. In a state of releasing the screw lock by releasing the mesh of the female screw portion and the male screw portion, in accordance with moving the crown head by an urge force of an elastic member, the rotational force transmitting portion is fitted to the rotational force receiving portion. Therefore, when the crown head is operated to rotate in a state of releasing the screw lock, the rotation is transmitted to the crown shaft by way of the rotational force transmitting portion and the rotational force receiving portion which are fitted together and the hand setting stem can be rotated (refer to, for example, JP-A-2005-127816 (paragraphs 0011-0055, FIG. 1-FIG. 5)). 
     According to the timepiece of Patent Reference 1, there is achieved an advantage of capable of lightly operating a screw locking operation since in operating to rotate to bring the female screw portion of the crown head in mesh with the male screw portion of the pipe in order to achieve the screw lock state, the hand setting stem is not rotated cooperatively therewith. 
     However, when the screw lock is released, during a time period after releasing the mesh of the female screw portion and the male screw portion, until the rotational force transmitting portion is engaged with the rotational force receiving portion, the crown head is not supported and there is a possibility of shaking the crown head. Therefore, there is a case in which the operation of the crown head becomes unstable and the rotational force transmitting portion cannot smoothly been gaged with the rotational force receiving portion. Further, by the same reason, in bringing the female screw portion in mesh with the male screw portion in order to constitute the screw lock state, when the crown head is unstable, there is a case in which the mesh cannot smoothly be carried out and when a user forcibly constitutes the mesh under the state, there is conceivable a concern of damaging the screw portion. 
     Further, according to the timepiece of Patent Reference 1, the female screw portion having a diameter smaller than that of the rotational force transmitting portion and being integral with the crown head is provided continuously to the rotational force transmitting portion. Thereby, when the rotational force transmitting portion having the deformed shape is formed on an inner side of the crown head, the female screw portion constitutes a hindrance against working of the rotational force transmitting portion. Therefore, working using a shaper cannot be carried out. Along therewith, punching cannot be carried out when working is carried out by using a press. In this way, working suitable for mass production performance cannot be carried out, and therefore, special devise is needed for working the rotational force transmitting portion and a concern of being difficult to work the rotational force transmitting portion accurately is conceivable. 
     SUMMARY OF THE INVENTION 
     It is an aspect of the present invention to provide a portable timepiece capable of promoting an operability of a crown head in a state of releasing screw lock. 
     It is another aspect of the present invention to provide a method of fabricating a crown provided to a portable timepiece capable of promoting a workability of a rotational force transmitting portion provided to a crown head of a crown used for achieving the aspect mentioned above. 
     A portable timepiece of the invention is a portable timepiece, wherein a case band including a timepiece movement is attached with a pipe having a male screw portion disposed on an outer side of the case band, a crown connected to a hand setting stem for transmitting a rotational force to the timepiece movement is brought in mesh with the male screw portion attachably and detachably, and the crown is held so as not to be rotated by bringing the crown in mesh with the male screw portion, and is characterized in that a crown guide having a diameter to be brought into contact with an inner peripheral face of a head main body constituting a cylindrical shape of a crown head is provided at a portion arranged at the outside of the pipe of the crown shaft for cooperatively moving the hand setting stem in a state of releasing the crown and the male screw portion from being brought in mesh with each other and covered by the crown head provided to the crown, and a movement in an axial direction of the crown head is guided by the crown guide. 
     According to the invention, the crown guide provided at the crown shaft is lightly brought into contact with or extremely proximate to the inner peripheral face of the crown head, and therefore, the crown head can be supported by the crown guide from the inner side. Therefore, when the crown head is moved in the axial direction in a state of releasing the screw lock for the crown, the movement of the crown head can be guided by the crown guide. Therefore, the crown head can be moved in the axial direction stably so as not to shake the crown head. Thereby, when brought into the screw lock state, the female screw portion of the screw ring can properly be started to be brought in mesh with the male screw portion of the pipe. 
     According to a preferable embodiment of the portable timepiece of the invention, it is characterized that a rotational force transmitting portion including a first engaging portion is provided at an inner face of the head main body in the cylindrical shape provided to the crown head, and a rotational force receiving portion including a second engaging portion formed by a shape in correspondence with the first engaging portion and engaged and detached with and from the first engaging portion by the movement in the axial direction of the crown head serves also as the crown guide. 
     According to the invention, it is not necessary to form the crown guide and the rotational force receiving portion at the crown shaft to be aligned along the axial direction. Therefore, in comparison with the constitution of aligning the crown guide and the rotational force receiving portion, a length of the crown shaft and a length of the crown can be prevented from being prolonged. Along therewith, one of the crown guide and the rotational force receiving portion do not constitute a hindrance in working other thereof as in the constitution of aligning the crown guide and the rotational force receiving portion, and therefore, the crown shaft can easily be worked. 
     Further, a portable time piece of the invention is a portable time piece, wherein a case band including a timepiece movement is attached with a pipe having a male screw portion disposed on an outer side of the case band, a crown connected to a hand setting stem for transmitting a rotational force to the timepiece movement is brought in mesh with the male screw portion attachably and detachably, and the crown is held so as not to be rotated by bringing the crown in mesh with the male screw portion, the crown including a crown shaft including a rotational force receiving portion of a deformed shape formed with a first engaging portion at an outer periphery thereof, having a diameter larger than a diameter of the male screw portion, arranged at outside of the pipe and cooperatively moving the hand setting stem in a state of releasing the crown and the male screw portion from being brought in mesh with each other, a crown head, wherein other end of a head main body opening one end thereof is closed by a closed portion, further, an inner periphery of the head main body includes a rotational force transmitting portion, a ring mounting face in a circular shape, and an inner peripheral face in a circular shape, the rotational force transmitting portion is constituted by a shape having a second engaging portion engaged with and detached from the first engaging portion and fitted attachably and detachably to the rotational force receiving portion, the ring mounting face is formed on the one end side from the rotational force transmitting portion by diameter equal to or larger than a maximum diameter of the rotational force transmitting portion, and the inner peripheral face is formed on the other end side from the rotational force transmitting portion by a diameter equal to or larger than the maximum diameter of the rotational force transmitting portion and a diameter brought into outer contact with the first engaging portion, a screw ring including a female screw portion attachably and detachably brought in mesh with the male screw portion and having a diameter smaller than a diameter of the rotational force receiving portion and mounted to the ring mounting face, and an elastic member squeezed between the crown head and the crown shaft for urging the crown head in a direction of being separated from the case band. 
     According to the invention, the first engaging portion provided to the rotational force receiving portion of the crown shaft is lightly brought into contact with or extremely proximate to the inner peripheral face of the crown head, and therefore, the crown head can be supported by the rotational force receiving portion from the inner side. Therefore, when the crown head is moved in the direction of being separated from the case band by the urge force of the elastic member in accordance with releasing the screw look for the crown, and when the crown head is moved to the case band against the urge force of the elastic member by bringing about the screw lock state from the state of releasing the screw lock for the crown, the movement of the crown head can be guided by the rotational force receiving portion. Therefore, the crown head can be moved in the axial direction stably so as not to shake the crown head, thereby, in bringing about the screw lock state, the female screw portion of the screw ring can properly started to be brought in mesh with the male screw portion of the pipe. When the crown head is moved in the direction of being separated from the case band, the screw ring impinges on the rotational force receiving portion from the side of the case band, and therefore, the crown head can be prevented from being detached by the urge force of the elastic member by constituting a stopper by the rotational force receiving portion. 
     According to the preferable embodiment of the portable timepiece of the invention, an inserting portion formed to be brought into inner contact with the female screw portion is made to be continuous to the male screw portion of the pipe, and a length of the inserting portion is constituted by a length inserted into the screw ring in a state of disengaging the screw ring from being brought in mesh with the male screw portion. 
     According to the mode of the invention, when the crown is detached from the male screw portion, the inserting portion of the pipe is inserted to the screw ring mounted to the crown head, and the screw ring is guided by the inserting portion from the inner side. Thereby, the crown head can be moved in the axial direction by making the crown head stable so as not to be shaken further by the rotational force receiving portion of the crown shaft and the inserting portion of the pipe. 
     According to a preferable embodiment of the portable timepiece of the invention, the first and the second engaging portions are constituted by serrations. 
     According to the mode of the invention, in engaging the second engaging portion provided to the rotational force transmitting portion of the crown head with the first engaging portion provided to the rotational force receiving portion of the crown shaft by releasing the screw lock, when time and labor of rotating the crown head is needed, an amount of the rotation is reduced. In a state of releasing the screw lock in this way, an operability of the crown head for bringing the rotational force transmitting portion in mesh with the rotational force receiving portion is promoted, and therefore, a shift to an operation of cooperatively moving the crown shaft is smooth. 
     According to the preferable embodiment of the portable timepiece of the invention, the head main body and the closed portion are integrally formed. 
     According to the mode of the invention, there is not a seam between the head main body and the closed portion, and therefore, in comparison with a case of having the seam, an adverse influence is not effected on the contact feeling of the finger in operating the crown and also an outlook of the crown can be promoted. 
     Further, there is provided a method of fabricating a crown included to a portable timepiece of the invention, wherein for a head material in which other end of a head main body opening one end is closed by a closed portion, and which includes a first space in a circular shape partitioned by an inner peripheral face of a circular shape having a diameter equal to or larger than a maximum diameter of a worked projected portion between the worked projected portion provided continuously in a peripheral direction at an inner periphery of the head main body and the closed portion and including a second space in a circular shape partitioned by a ring mounting face in a circular shape having a diameter equal to or larger than the maximum diameter of the worked projected portion between the worked projected portion and the opened one end of the head main body, by a work member reaching the first space by crossing the worked projected portion from the second space, the first engaging portion is worked into the worked projected portion, and a crown head formed with a rotational force transmitting portion in a deformed shape is prepared, wherein for a crown shaft material including a shaft main portion and a shaft end portion in a circular shape expanded integrally from an outer periphery of one end portion of the shaft main portion, a second engaging portion brought into inner contact with the inner peripheral face is worked at an outer peripheral portion of the shaft end portion by a work member crossing the outer peripheral portion of the shaft end portion by being moved in an axial direction of the crown shaft material, thereby, a crown shaft formed with a rotational force receiving portion of a shape of being attachably and detachably fitted with the rotational force transmitting portion is prepared, wherein a ring material is worked by a work member penetrating the ring material in the axial direction by crossing an inner peripheral portion of the ring material, thereby, a screw ring formed by including a female screw portion having a diameter smaller than a diameter of the rotational force receiving portion is prepared. The crown head is covered to the crown shaft and the rotational force receiving portion is contained in the first space while squeezing an elastic member in a compressed state between the closed portion of the crown head and the crown shaft. Thereafter, the screw ring is mounted to the ring mounting face by press-fitting the screw ring into the second space. 
     According to the invention, the head material constituting the crown head includes the first space and the second space on the both sides of the worked projected portion provided continuously in the peripheral direction of the inner periphery thereof, the diameters of the ring mounting face formed by the first space and the inner peripheral face formed by the second space are made to be equal to or larger than the maximum diameter of the worked projected portion, and therefore, when the rotational force transmitting portion is formed at the worked projected portion of the head material by working the first engaging portion, the work member for working the first engaging portion is not hindered from crossing to pass through the worked projected portion by the ring mounting face and an inner peripheral face. Therefore, the rotational force transmitting portion can be worked at the crown head by working using a shaper or punching by using a press. 
     According to the portable timepiece of the invention, when the crown head is moved in the axial direction, the movement of the crown head is guided by the rotational force receiving portion from the inner side of the crown head, the crown head is restrained from being shaken in the state of disengaging the screw lock, and therefore, the operability of the crown head in the state of releasing the screw lock can be promoted. 
     According, to the method of fabricating the crown included to the portable timepiece of the invention, the rotational force transmitting portion can be worked for the crown head by working using a shaper or punching using a press, and therefore, a workability of the rotational force transmitting portion of the crown head can be promoted. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view showing a wrist watch according to a first embodiment of the invention. 
         FIG. 2  is a sectional view taken along a line F 2 -F 2  of  FIG. 1  showing a screw lock state of a crown. 
         FIG. 3  is a sectional view taken along the line F 2 -F 2  of  FIG. 1  showing a state of releasing the screw lock state of the crown. 
         FIG. 4  is a sectional view taken along a line F 4 -F 4  of  FIG. 3 . 
         FIG. 5  is a front view showing a crown head provided to the wrist watch of  FIG. 1 . 
         FIG. 6  is a sectional view showing a head material of forming the crown head provided to the wrist watch of  FIG. 1 . 
         FIG. 7  is a sectional view showing a screw ring provided to the wrist watch of  FIG. 1 . 
         FIG. 8  is a sectional view in correspondence with  FIG. 4  showing a crown provided to a wrist watch according to a second embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     A first embodiment of the invention will be explained in reference to  FIG. 1  through  FIG. 7 . 
     In  FIG. 1 , notation  10  designates a wrist watch as a portable timepiece. The wrist watch  10  contains a dial  12  as shown by  FIG. 2  and  FIG. 3  and a timepiece movement  13 , not illustrated, and the like at inside of a timepiece exterior assembly  11 . As the timepiece movement  13 , there is used a mechanical type timepiece movement of a hand winding type constituting a power source by a mainspring, or an automatic winding type, or a type using both of the hand winding and the automatic winding. Further, in place thereof, there can also be used a timepiece movement of a type capable of switching time indication or the like on the dial  12  by selecting a digital indication and an analog indication. 
     As shown by  FIG. 2  and  FIG. 3 , the timepiece exterior assembly  11  is formed by mounting a cover glass  15  in a liquid tight manner to a front face constituted by one face in a thickness direction of a case band  14  made of a metal constituting a ring-like shape and screwing a case back  16  comprising a metal or the like in a liquid tight manner to a back face constituted by the other face in the thickness direction of the case band  14 . The dial  12  is optically recognizable or viewable through the cover glass  15 . The case back  16  is removable. Further, in  FIG. 1  through  FIG. 3 , notation  18  designates a bezel in a ring-like shape attached to the timepiece exterior assembly  11  to be able to be operated to rotate. The bezel  18  can be rotated by constant angles and is held at an arbitrary rotational position by a holding member  19  capable of being deformed elastically and engaged and disengaged to and from the bezel  18 . The bezel  18  and the holding member  19  can be omitted. 
     As shown by  FIG. 2  and  FIG. 3 , a portion of the case band  14  is opened with a pipe attaching hole  17  penetrating the case band  14  in a diameter direction. One end of the pipe attaching hole  17  is opened to a space  14   a  at inside of the case band surrounded by the case band  14 , and other end of the pipe attaching hole  17  is opened to an outer side face  14   b  of the case band  14 . 
     The case band  14  is attached with a pipe  21  by being inserted to the pipe attaching hole  17  from an outer side of the case band by brazing or the like. Notation  22  in  FIG. 2  and  FIG. 3  designates a brazing material. The pipe  21  made of a metal, for example, stainless steel is constituted by a shape of a circular cylinder, both ends in an axial direction thereof are respectively opened, and the pipe  21  includes a pipe end portion  21   a  arranged at an outer portion of the case band  14 , and an outer periphery of the pipe end portion  21   a  includes a male screw portion  24  for holding a crown  31  in a screw lock state. 
     The pipe end portion  21   a  includes an inserting portion  25  continuous to the male screw portion  24  in a direction of being remote from the case band  14 . As shown by  FIG. 3 , the inserting portion  25  is provided with a length inserted to a screw ring  34 , mentioned later, even in a state of releasing screw lock. An outer diameter of the inserting portion  25  is constituted by a diameter which is smaller than a diameter of the male screw portion  24  and brought into contact (inner contact) with a female screw portion  43 , mentioned later, from an inner side thereof. 
     The crown  31  includes a crown shaft  32 , a crown head  33 , the screw ring  34 , an elastic member, for example, a coil spring  35 . 
     The crown shaft  32  is made of, for example, a metal, preferably, stainless steel and includes an inserting shaft portion  32   a  in a shape of a circular column inserted from outside of the case band  14  into the pipe  21 , and a rotational force receiving portion  32   b  constituted by a shaft end portion arranged at outside of the pipe  21  continuously integrally to the inserting shaft portion  32   a  as shown by  FIG. 2  and  FIG. 3 . 
     The rotational force receiving portion  32   b  is expanded in a circular shape from an outer periphery of an end portion of the inserting shaft portion  32   a . A diameter of the rotational force receiving portion  32   b  is not less than an outer diameter of the male screw portion  24 . An outer diameter of the rotational force receiving portion  32   b  is constituted by a size brought into inner contact with an inner peripheral face  46 , mentioned later, that is, brought into contact with the inner peripheral face  46  from an inner side of the crown head  33 , thereby, the rotational force receiving portion  32   b  serves also as a crown guide. 
     Therefore, the rotational force receiving portion  32   b  is constituted by a deformed shape by including a first engaging portion serving as an engagement for receiving a rotational force at an outer peripheral portion thereof. Specifically, as shown by  FIG. 4 , there is formed the rotational force receiving portion  32   b  in a shape of an outer teeth gear by including a serration formed with a plurality of teeth (first engaging portion)  36  projected outwardly at a peripheral portion of the rotational force receiving portion  32   b  and aligned in a peripheral direction of the peripheral portion preferably continuously. Although according to an example of  FIG. 4 , a triangular teeth serration is constituted, the invention is not restricted thereto. The tooth  36  of the rotational force receiving portion  32   b  may be constituted by a spline of a square shape or the like. 
     The crown shaft  32  is provided with a screw hole  37  cut from a front end side of the inserting shaft portion  32   a  along the axial direction and is provided with a spring containing hole  38  opened to a center portion of an end face of the rotational force receiving portion  32   b.    
     A hand setting stem  39  for transmitting the rotational force of the crown  31  to the timepiece movement  13  is screwed from an inner side of the case band  14  to the screw hole  37  of the inserting shaft portion  32   a . The hand setting stem  39  and the crown shaft  32  connected to each other, thereby, cannot be moved in the axial direction. A recessed portion in a ring-like shape formed at an outer periphery of a front end portion of the inserting shaft portion  32   a  is mounted with a waterproof packing  40  in a ring-like shape constituted by an elastic material of rubber or the like. The waterproof packing  40  is elastically brought into close contact with inner peripheries of the ring-like recessed portion and the pipe  21 , thereby, the waterproof is carried out between the inner periphery of the pipe  21  and the crown shaft  32 . 
     The crown head  33  is made of a metal of, for example, stainless steel or the like, and is formed in a cap-like shape by including a head main body  41  one end of which is opened and a closed portion  42  closing other end of the head main body  41  as shown by  FIG. 2  and  FIG. 3 . The head main body  41  and the closed portion  42  are integral as a preferable example. Thereby, there is not a seam between the head main body  41  and the closed portion  42 , and therefore, in comparison with a case of including a seam, an adverse influence is not effected on a contact feeling of the finger in operating the crown  31  and also an outlook of the crown  31  can be promoted. 
     As shown by  FIG. 2 , the head main body  41  is formed by a shape of a circular cylinder constituting a size capable of containing the male screw portion  24  and the inserting portion  25 , and an outer periphery thereof includes recesses and projections  41   a  (refer to  FIG. 4  and  FIG. 5 ) for stopping slipping in being operated to rotate. An opened one end  41   b  of the head main body  41  is made to be brought into contact with and separated from the outer side face  14   b  of the case band  14 . 
     The head main body  41  includes a rotational force transmitting portion  44 , and a ring mounting face  45  and the inner peripheral face  46  provided on both sides of the rotational force transmitting portion  44  at an inner periphery thereof. 
     The rotational force transmitting portion  44  is provided at a middle portion in the axial direction of the head main body  41 . The rotational force transmitting portion  44  is releasably engageable with and disengageable from the rotational force receiving portion  32   b  in accordance with a movement in the axial direction of the crown head  33 , and is constituted by a shape similar to that of the first engaging portion of the rotational force receiving portion  32   b , and therefore, in the case of the embodiment, as exemplified in  FIG. 4  and  FIG. 5 , the rotational force transmitting portion  44  is constituted by a deformed shape. Specifically, the rotational force transmitting portion  44  having a shape of an inner teeth gear is formed by being projected from the inner periphery of the head main body  41  to a center portion of the head main body  41  and including a serration produced by a plurality of teeth (second engaging portions)  44   a  aligned in a peripheral direction of the inner periphery, preferably continuously, serving as an engagement for transmitting the rotational force. Although in the example of  FIG. 4  and  FIG. 5 , a triangular teeth serration is constituted, the invention is not restricted thereto. The tooth  44   a  of the rotational force transmitting portion  44  may be constituted by a spline of a square shape or the like. 
     The ring mounting face  45  is formed by an inner peripheral portion on a side of one end  41   b  of the head main body  41  from the rotational force transmitting portion  44 . As shown by  FIG. 5 , the ring mounting face  45  is constituted by a circular shape. A diameter of the ring mounting face  45  is equal to or larger than a maximum diameter of the rotational force transmitting portion  44 . Here, the maximum diameter of the rotational force transmitting portion  44  indicates a circle passing a tooth bottom of the tooth  44   a  produced by the serration, and the ring mounting face  45  is formed by a diameter larger than that of the tooth bottom circle as a preferable example according to the embodiment. 
     The inner peripheral face  46  is formed by an inner peripheral portion on a side of the closed portion  42  of the head main body  41  from the rotational force transmitting portion  44 . The inner peripheral face  46  is constituted by a circular shape and a length A in the axial direction of the inner peripheral face  46  (refer to  FIG. 3 ) is equal to or larger than an axial direction moving distance B (refer to  FIG. 3 ) of the crown head  33  constituting a reference by the outer side face  14   b  of the case band  14 . A diameter of the inner peripheral face  46  is equal to or larger than the maximum diameter (the tooth bottom circle) of the rotational force transmitting portion  44  and is a diameter at which the inner peripheral face  46  is brought into outer sliding contact with the respective teeth  36  of the rotational force receiving portion  32   b , that is, brought into slidable contact with the respective teeth  36  from an outer side of the rotational force receiving portion  32   b  and is the same as the diameter of the tooth bottom circle of the rotational force transmitting portion  44  according to the embodiment. 
     The screw ring  34  shown in  FIG. 7  and the like is made of, for example, a metal and includes the female screw portion  43  removably brought in mesh with the male screw portion  24  to achieve the screw lock state of the crown  31  at an inner periphery thereof. An inner diameter of the screw ring  34 , that is, a nominal diameter of the female screw portion  43  is smaller than that of the rotational force receiving portion  32   b  and is constituted by a size brought into contact (outer contact) with an outer periphery of the inserting portion  25  from outside thereof. An outer diameter of the screw ring  34  is substantially the same as the diameter of the ring mounting face  45 . The screw ring  34  is mounted to the ring mounting face  45  by being press-fitted to the head main body  41  until impinging on a stepped portion  33   a  (refer to  FIG. 6 ) in a ring-like shape produced by the rotational force transmitting portion  44  and the ring mounting face  45 . Therefore, by the mounting, the screw ring  34  is arranged contiguous to a side of the one end  41   b  relative to the rotational force transmitting portion  44 . 
     The coil spring  35  is contained in the spring containing hole  38  of the crown shaft  32  and is squeezed between a center portion of the closed portion  42  opposed to the containing hole  38  of the crown shaft  32  and the crown shaft  32 . The coil spring  35  always urges the crown head  33  in a direction of separating from the outer side face  14   b  of the case band  14 . 
     In the wrist watch  10  having the above-described constitution,  FIG. 2  shows a state in which the crown  31  is arranged at a position of not being pulled out (generally referred to as ‘zero stage’). At the ‘zero stage’, the female screw portion  43  of the crown  31  is brought in mesh with the male screw portion  24  of the pipe  21 , the one end  41   b  of the head main body  41  and the screw ring  34  are brought into contact with the outer side face  14   b  of the case band  14 , thereby, the crown  31  is positioned to the case band  14 . 
     Along therewith, the inserting portion  25  of the pipe  21  is inserted through the screw ring  34  and the rotational force transmitting portion  44  of the crown head  33  is opposed to the outer periphery of the inserting portion  25 . Further, the rotational force transmitting portion  44  is separated in a direction of the outer side face  14   b  of the case band  14  relative to the rotational force receiving portion  32   b  of the crown shaft  32 , and the rotational force receiving portion  32   b  of the crown head  33  and the rotational force transmitting portion  44  of the crown shaft  32  are maintained in a state of not having a coupling relationship. Under the state, the rotational force receiving portion  32   b  is arranged to be proximate to the inner face of the closed portion  42  of the crown head  33  and front ends of the respective teeth  36  are disposed to be brought into inner contact with the inner peripheral face  46  of the crown head  33 . Therefore, the rotational force receiving portion  32   b  supports the crown head  33  from an inner side. 
     As described above, at the ‘zero stage’, the crown  31  is brought into a state of being locked by the screw. Under the state, the male screw portion  24  and the female screw portion  43  are brought in mesh with each other. Therefore, the crown head  33  is not moved in the axial direction although the coil spring  35  is brought into a state of being strongly compressed between the closed portion  42  of the crown head  33  and the crown shaft  32  and the crown head  33  is urged in the direction of being separated from the case band  14 . 
     When time of the timepiece movement  13  is set, the crown head  33  brought into the screw lock state is pulled out to a position referred to as ‘1 stage’ to be operated to rotate. That is, first, the crown head  33  is rotated in a loosening direction, and the female screw portion  43  is brought into a state of being detached from the male screw portion  24 . In this case, the crown head  33  and the crown shaft  32  are not provided with the coupling relationship, and therefore, the crown shaft  32  is not rotated cooperatively with the crown head  33  in accordance with an operation of rotating the crown head  33  releasing from mesh. 
     Simultaneous with releasing the mesh of the screw portion, by a spring force (urge force) of the coil spring  35 , the crown head  33  is moved to separate from the outer side face  14   b  of the case band  14  along an axial direction of the crown shaft  32 . 
     The crown shaft  32  and the crown head  33  are connected in accordance with a movement in the axial direction of the crown head  33 . That is, the rotational force transmitting portion  44  constituting the shape of the inner teeth gear is fitted to the rotational force receiving portion  32   b  constituting the shape of the outer teeth gear, and the crown shaft  32  and the crown head  33  are coupled to be held to be cooperatively rotated along an axis. 
     Simultaneous therewith, the screw ring  34  having the female screw portion  43  impinges on a side face on a side of the case band  14  of the rotational force receiving portion  32   b , and therefore, the movement of the crown head  33  in the axial direction is restricted by constituting a stopper by the rotational force receiving portion  32   b  and the crown head  33  is stopped from being detached. By the restriction, the coupling, in other words, the engagement of the first engaging portion and the second engaging portion is maintained, and the crown  31  released from the screw lock state is maintained at the pull out position referred to as ‘1 stage’ as shown by  FIG. 3 . Along therewith, the screw ring  34  is arranged to be fitted to be brought into outer contact with the inserting portion  35  of the crown shaft  32 . 
     In connecting the crown shaft  32  and the crown head  33 , there is a case in which time and labor of more or less rotating the crown head  33  is needed. The teeth  44   a  of the rotational force transmitting portion  44  and teeth  36  of the rotational force receiving portion  32   b  are formed by the serrations. Therefore, when the time and labor is needed for bringing the teeth  36  and the teeth  44   a  in mesh with each other as described above, an amount of rotation thereof is constituted by at least an amount of 1 pitch of the teeth. In a state of releasing the screw lock in this way, an operability of the crown head  33  for bringing the rotational force transmitting portion  44  in mesh with the outer peripheral portion of the rotational force receiving portion  32   b  is excellent. 
     By manually rotating the crown head  33  of the crown  31  at the pull out position of the crown head  33  explained above (refer to  FIG. 3 ), rotation of the crown head  33  is transmitted to the crown shaft  32  by way of the rotational force transmitting portion  44  and the rotational force receiving portion  32   b . In accordance therewith, the rotational force is exerted to the timepiece movement  13  by way of the hand setting stem  39 , and therefore, adjustment of the timepiece movement  13  of setting time or the like can be carried out. 
     After the adjustment, the crown  31  is brought into the lock state (refer to  FIG. 2 ) again. The operation of achieving the screw lock state is carried out first, by pushing back the crown head  33  in the direction of the case band  14  against the coil spring  35 , thereafter, the female screw portion  43  of the screw ring  34  provided to the crown  31  is rotated in a fastening direction to be screwed to the male screw portion  24  of the pipe  21 . Thereby, the one end  41   b  of the crown head  33  and the screw ring  34  are brought into contact with the outer side face  14   b  of the case band  14 , and therefore, the crown  31  can be brought into the screw lock state such that the crown  31  is not carelessly rotated in carrying the wrist watch  10  or the like. 
     In the operation of providing the screw lock state, first, in accordance with pushing back the crown head  33  in the direction of the case band  14 , the rotational force transmitting portion  44  is detached from the rotational force receiving portion  32   b , and therefore, connection of the crown head  33  and the crown shaft  32  is released. Further, thereafter, by operating to rotate the crown head  33 , the female screw portion  43  is brought in mesh with the male screw portion  24 . 
     The screw lock operation which is carried out by rotating the crown head  33  in the fastening direction in this way is carried out in a state in which the crown head  33  and the crown shaft  32  are not connected, and therefore, rotation of the crown head  33  in the fastening direction is not transmitted to the crown shaft  32 . 
     In accordance with the screw lock operation to provide the screw lock state as described above, the crown shaft  32  is rotated, rotation is not transmitted to the mechanical type timepiece movement  13 , and therefore, in the screw lock operation, the main spring provided to the timepiece movement  13  is prevented from constituting a load. Therefore, even in a state of, for example, winding up the mainspring considerably, the screw lock operation of the crown  31  can lightly be carried out and the operability is excellent. 
     Further, when the timepiece movement  13  is not of a mechanical type but is provided with a function of changing an operation mode by the crown  31  arranged at the position of ‘zero stage’, as described above, the rotational force is prevented from being propagated to the timepiece movement in accordance with the screw lock operation of the crown  31 , and therefore, the operation mode is not carelessly changed. 
     Further, as described above, in accordance with being able to lightly carry out the screw lock operation of the mechanical type timepiece movement  13  having the mainspring, an excessive rotation operating force is not applied to the male screw portion  24  and the female screw portion  43 , and therefore, durability of the screw portions  23  and  43  can be promoted. 
     Further, as described above, regardless of movement in the axial direction of the crown head  33  in the screw lock operation and in releasing the screw lock state, the crown shaft  32  is not moved in the axial direction. Therefore, connection of the hand setting stem  39  and the crown shaft  32  can be carried out by a simple screwing structure without needing a device for preventing the movement in the axial direction of the crown shaft  32  from being propagated to the hand setting stem  39  at the hand setting stem  39  and the crown shaft  32 . Therefore, cost of working the hand setting stem  39  can be reduced, and therefore, the constitution can contribute to a reduction in cost of a total of the wrist watch. 
     Furthermore, the screw shaft can be adopted for the hand setting stem  39 , and therefore, in assembling the wrist watch  10 , the hand setting stem  39  can be attached to the crown shaft  32  at a later stage without being restricted by preparing a crown attached with a hand setting stem in which the hand setting stem  39  is previously fixed to the crown  31 . Thereby, the hand setting stem  39  previously worked with a screw portion to be maximally long can be cut by a necessary length to be screwed to be connected to the crown shaft  32  by being adapted to a size of the timepiece exterior assembly  11  which differs by a type of the wrist watch  10 , a dimension necessary for achieving the screw lock state and the like. Therefore, in fabrication, general purpose performance of the hand setting stem  39  is increased, the hand setting stem  39  can commonly be used by a number of kinds of the wristwatches  10  and can contribute to a reduction in a cost of the total of the wrist watch  10  in accordance therewith. 
     As described above, in the state of releasing the screw lock, the respective teeth  36  of the rotational force receiving portion  32   b  of the crown shaft  32  are brought into inner contact with the inner peripheral face  46  of the crown head  33 . That is, the respective teeth  36  are slightly brought into contact with or extremely proximate to the inner peripheral face  46 . Thereby, the crown head  33  can be supported by the rotational force receiving portion  32   b  from the inner side. 
     Therefore, when the crown head  33  is moved in the direction of being separated from the case band  14  by the urge force of the coil spring  35  in accordance with releasing the screw lock for the crown  31 , and when the crown head  33  is moved in the direction of the case band  14  against the urge force of the coil spring  35  in bringing about the screw lock state from the state of releasing the screw lock for the crown  31 , the axial movement of the crown head  33  can be guided by the rotational force receiving portion  32   b  throughout a major part of the range of axial movement of the crown  31 . Therefore, the crown head  33  can be moved in the axial direction stably without shaking the crown head  33 . 
     Further, the screw ring  34  is arranged to be brought into outer contact with the inserting portion  25  of the pipe  21  as described above until the female screw portion  43  is started to be brought in mesh with the male screw portion  24  from the state of releasing the screw lock for the crown  31 . In other words, the inserting portion  25  of the pipe  21  is inserted to the screw ring  34  and the screw ring  34  is guided by the inserting portion  25  from the inner side. Also in this respect, the crown head  33  can be moved in the axial direction stably without shaking the crown head  33 . 
     As described above, the crown head  33  can be moved in the axial direction by making the crown head  33  stable so as not to be shaken by the rotational force receiving portion  32   b  of the crown shaft  32  and the inserting portion  25  of the pipe  21 . Thereby, when the crown  31  is brought into the screw lock state, the female screw portion  43  of the screw ring  34  is restrained from being forcibly brought in mesh with the male screw portion  24  of the pipe  21 , and the female screw portion  43  of the screw ring  34  can be started to be properly brought in mesh with the male screw portion  24  of the pipe  21 . 
     Next, a procedure of fabricating the crown  31  will be explained. 
     First, the crown shaft  32 , the crown head  33 , the screw ring  34 , and the coil spring  35  which is not needed to work are prepared. 
     The screw ring  34  is provided by screwing an inner periphery of a material of a ring type, not illustrated. The female screw portion  43  can be formed by the working. In this case, the ring type material which is a part separate from the crown head  33  is used, and therefore, an effective length of the female screw portion  43  in accordance with a width of the material can maximally be ensured. 
     The crown shaft  32  is provided by carrying out necessary working of providing the plurality of teeth  36  or the like for a material of the crown shaft, not illustrated. The material of the crown shaft includes a shaft main portion and a shaft end portion in a circular shape expanded integrally from an outer periphery of one end portion of the shaft main portion to an outer side. The ring-like recessed portion for attaching the waterproof packing  40 , the screw hole  37  and the spring containing hole  38  are machined for the shaft main portion. The plurality of teeth  36  are worked by machining using a shaper or punching using a press by a work member, not illustrated, moved in an axial direction of the material of the crown shaft for the outer peripheral portion of the shaft end portion. 
     The crown head  33  is provided by carrying out necessary working for a head material. As shown by  FIG. 6 , according to the head material  51 , other end of the head main body  41  one end of which is opened is closed by the closed portion  42 , a worked projected portion  52  is provided at an inner periphery of the head main body  41 , and the head material  51  includes a first space  53  and a second space  54  at inside of the head main body  41  by constituting a boundary by the worked projected portion  52 . The worked projected portion  52  constitutes a circular ring shape continuous in a peripheral direction at an inner periphery of the head main body  41 . The first space  53  is partitioned by a maximum diameter of the worked projected portion  52 , that is, the inner peripheral face  46  in a circular shape having a diameter equal to or larger than a diameter of a circle drawn by passing a projected base portion, and is formed between the worked projected portion  52  and the closed portion  42 . The second space  54  is partitioned by the ring mounting face  45  of the circular shape having a diameter equal to or larger than the maximum diameter of the worked projected portion  52  and is formed between the worked projected portion  52  and the opened one end  41   b  of the head main body  41 . 
     The head material  51  is worked for the worked projected portion  52 . In working the worked projected portion  52 , the plurality of teeth  44   a  are worked at the worked projected portion  52  by a work member, not illustrated, reaching the first space  53  from the second space  54  by passing the worked projected portion  52  and the rotational force transmitting portion  44  of a shape attachably and detachably fitted to the rotational force receiving portion  32   b  is formed. In this case, the teeth  44   a  are worked by machining by using a shaper or punching by using a press. Further, a two-dotted chain line in  FIG. 6  indicates a depth of working the worked projected portion  52 . 
     According to the working, by the constitution of the head material  51  for constituting the crown head  33 , the work member working the plurality of teeth  44   a  at the worked projected portion  52  is not hindered from passing through the worked projected portion  52  by the ring mounting face  45  and the inner peripheral face  46 , and therefore, a workability of the rotational force transmitting portion  44  provided to the crown head  33  can be promoted. In addition thereto, the screw ring  34  is not integral with the crown head  33  but is attached to the crown head  33 , and therefore, the screw ring  34  does not constitute a hindrance in working the rotational force transmitting portion  44  for the head material  51 . 
     Therefore, despite that other end of the head material  51  is closed by the closed portion  42 , the rotational force transmitting portion  44  can easily be worked at the worked projected portion  52  by working by using a shaper or punching by using a press suitable for mass production performance and the teeth  44   a  of the rotational force transmitting portion  44  can accurately be worked. 
     Next, the crown shaft  32 , the crown head  33 , the screw ring  34  and the coil spring  35  which are prepared are assembled. 
     First, the crown head  33  is made to cover the crown shaft  32  while squeezing the coil spring  35  in a compressed state between the closed portion  42  of the crown head  33  and the crown shaft  32 . Thereby, the rotational force receiving portion  32   b  is contained in the first space  53 . Thereafter, the screw ring  34  is mounted to the ring mounting face  45  by press-fitting the screw ring  34  into the second space  54  of the crown head  33 . 
     Second Embodiment 
     A second embodiment of the invention will be explained in reference to  FIG. 8 . The second embodiment is basically the same as the first embodiment. Therefore, portions the same as those of the first embodiment are attached with notations the same as those of the first embodiment and an explanation thereof will be omitted, and an explanation will be given of portions different from those of the first embodiment as follows. 
     According to the second embodiment, the first engaging portion  36  provided at an outer peripheral portion of the rotational force receiving portion  32   b  is formed by a regular polygonal shape, specifically, a regular octagonal shape, in accordance therewith, also the second engaging portion  44   a  provided at the rotational force transmitting portion  44  fitted attachably and detachably to the rotational force receiving portion  32   b  is formed by a regular polygonal shape, specifically, a regular octagonal shape. Other than the point, the constitution is the same as that of the first embodiment including a constitution not shown in  FIG. 8 . 
     Therefore, also in the wrist watch  10  of the second embodiment, the problem which the invention is to solve can be solved by achieving an operation the same as that of the first embodiment.