Abstract:
A wrist-portable apparatus has a case housing a rotational display member and an operational shaft for undergoing rotational movement and sliding movement relative to the case so that the operational shaft may be axially displaced between a pushed-in position, in which the operational shaft is pushed into the case, and a drawn-out position, in which the operational shaft is drawn out from the case. A clutch assembly transmits rotational movement of the operational shaft to the display member to rotate the display member when the operational shaft is displaced to the drawn-out position and releases the transmission of the rotational movement of the operational shaft to the display member when the operational shaft is displaced to the pushed-in position. A manual control stem is integrally connected to an end of the operational shaft and is disposed on a side surface portion of the case for controlling rotation of the operational shaft and displacement of the operational shaft to the pushed-in and drawn-out positions.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a wrist-portable equipment, and more particularly to a wrist-portable apparatus provided with a display member rotating independently and separately from a gear train of circumferential divisional hour/minute/second. 
   2. Description of the Prior Art 
   In a wrist-portable equipment, a technology for rotating and operating a display member provided in an interior of a case member by a stem provided in the outside of the case member is currently known.  FIG. 8  is a plan view showing a body of a conventional wristwatch  100 .  FIG. 9  is a side elevational cross-sectional view showing a primary part of the wristwatch  100  described in  FIG. 9 . In  FIGS. 8 and 9 , the wristwatch  100  has a letter plate  102  and a scale ring  103  within a watch case  101 . 
   Also, a stem  104  for rotating the scale ring  103  is mounted independently and separately from a stem  105  for correcting hour/minute/second hands, on the side surface portion of the watch case  101 . This stem  104  is made of a metal member and has a cup-like shape. A cup bottom portion of this stem  104  is formed integrally so as to cover one end portion of a cylindrical operating shaft  106  made of a metal member. The operating shaft is inserted into the watch case  101  by passing through a pipe  107  which is securely provided to and penetrates through the watch case. 
   A gear  109  made of plastic or metal material is fitted into the vicinity of a tip end portion  108  of the inserted operating shaft  106 . This gear  109  is fixed to the operating shaft  106  by means of a ring-shaped fastening member  110  made of metal material. On the other hand, the above-described scale ring  103  is disposed with its display portion  111  facing the side of a watch glass  112 , its bottom portion  113  facing the side of the letter plate  102  and its side portion  114  facing the inner wall of the watch case  101 . The scale ring  103  has a rack  116  on a circumferential portion of its back surface. The scale ring  103  is engaged with the above-described gear  109  in this rack  116 . 
   In this wristwatch  100 , when the scale ring  103  is to be adjusted, the stem  104  is pinched by the fingers to rotate it in the axial direction by the fingers. Then, the operating shaft  106  formed integrally with the stem  104  is also rotated and the gear  109  fixed at its tip end portion  108  is also rotated. When the gear  109  is rotated, the rack  116  of the scale ring  103  engaging therewith is fed so that the scale ring  103  is also rotated. Thus, it is possible to adjust the scale ring  103  in a desired position by controlling the stem  104  while watching the scale ring through the glass  112  of the watch. 
   Thus, in the conventional wristwatch  100 , the scale ring  103  and the stem  104  mounted on the side surface portion of the watch case  101  are always coupled with each other through the operating shaft  106  and the gear  109 . For this reason, there are cases where, when it is mounted on the wrist, the stem  104  is rotated due to its contact with the body, wear cloth or the like and the scale ring  103  is displaced as a result. For this reason, in the conventional wristwatch  100 , a ring-shaped frictional member  117  made of elastic system material is provided on the inner wall surface of the stem  104  to thereby generate friction with the pipe  107  to suppress such an unnecessary rotation and to prevent malfunction of the scale ring  103 . Note that, the member  118  provided on the bottom surface portion  113  of the scale ring  103  is an annular cushion  118  made of elastic system material for preventing the displacement of the scale ring  103  during the rotation. The member  119  provided in the intermediate portion of the operating shaft  106  is an annular water-proof packing  119  made of elastic system material for sealing a gap between the operating shaft  106  and the pipe  107 . 
   However, the malfunction of the above-described scale ring  103  could not be completely prevented by the provision of the cushion  117  as described above. Also, it is necessary to consider frequent and vigorous contact which may take place between the stem  104  and the body or the like in the case where the wristportable equipment is worn while playing a sport or the like. On the other hand, unduly increasing the fastening degree of the above-described cushion  117  in order to prevent the above-described malfunction leads to the necessity of excessive force for rotating the stem  104  for performing adjustment of the scale ring  103 . Thus, there is a certain limitation regarding this approach. 
   SUMMARY OF THE INVENTION 
   Accordingly, in view of the above, an object of the present invention is to provide a wrist-portable apparatus or equipment that may effectively prevent the malfunction of a display member. 
   In order to attain the above-described object, the portable equipment according to this invention is characterized by comprising a case, an internal rotational ring that rotates independently and separately from a gear train of circumferential divisional hour/minute/second within the above-described case, and is used as a display member; an operating shaft that may be pushed in and drawn out from the above-described case; a clutch for transmitting the rotation of the above-described operating shaft to the above-described internal rotational ring and for releasing the transmission of the rotation by pushing in the above-described operating shaft; and a stem provided at one end portion of the above-described operating shaft and disposed on a side surface portion of the above-described case. 
   According to this invention, when the internal rotational ring is to be rotated, the stem is pinched and drawn out from the case by the fingers. Then, the operating shaft fixed to the stem is also shifted in a direction in which the stem is drawn out and the clutch works for effecting connection between the operating shaft and the internal rotational ring. Under this condition, when the stem is rotated, the operating shaft is also rotated and the rotation of the operating shaft is transmitted to the internal rotational ring by means of the clutch. Thus, it is possible to adjust the internal rotational ring while rotating the stem. Also, when the internal rotational ring is to be locked, the stem is pushed into the case. Then, the clutch is released by the opposite operation to the above-described draw operation so that the above-described operating shaft is separated from the internal rotational ring. Under this condition, even if the stem is accidentally rotated due to some reason, since the stem and the internal rotational ring are separated by means of the clutch so that the rotation of the stem is not transmitted to the internal rotational ring. Note that, the display member means a member for displaying letters or figures and includes a letter plate, a scale ring or the like. 
   Also, the wrist-portable equipment according to this invention, is characterized by comprising, in the above-described wrist-portable equipment, a first rotation transmission member fixed by inserting the above-described operating shaft therethrough and a second rotation transmission member provided in the above-described internal rotational ring and to which the rotation from the above-described first rotation transmission member is transmitted, wherein the rotational transmission between these first rotation transmission member and the second rotation transmission member is released by pushing in the above-described operating shaft. 
   In this invention, under the lock condition of the internal rotational ring, the first rotation transmission member and the second rotation transmission member are separated from each other. When this lock is to be released to rotate the internal rotational ring, the stem is pinched and the stem is drawn out of the case by the fingers. Then, the operating shaft provided on the stem is shifted in the direction in which the stem is drawn out together with the first rotation transmission member, and the first rotation transmission member is engaged or brought into frictional contact with the second rotational transmission member formed in the outer circumferential portion of the internal rotational ring. Under this condition, when the stem is rotated by the fingers, the rotating shaft is also rotated and then the first rotation transmission member is also rotated. Then, the second rotation transmission member engaging with this is also rotated and the internal rotational ring is rotated. Thus, the internal rotational ring may be adjusted by rotating the stem. 
   Furthermore, when the internal rotational ring is to be locked, the stem that has been drawn out is pushed into the case. Then, the operating shaft is shifted in the direction in which the stem is drawn out and the rotational transmission between the first rotation transmission member and the second rotation transmission member is released. Thus, the clutch is separated and malfunction of the internal rotational ring is prevented. Note that, it is preferable that the combination of the first rotation transmission member and the second rotation transmission member for constituting the clutch be a combination by which the effective rotation transmission is possible, such as a gear and a rack, a conical frictional member and a friction member or any other such combination. Note that, the transmission of rotation as described herein may include not only the case where direct transmission is established between the first rotation transmission member and the second rotation transmission member but also the case where an intermediate transmission member such as an intermediate gear or the like is used in its intermediate path. 
   Also, the wrist-portable equipment according to this invention is characterized in that the above-described clutch comprises: a bulged portion having a polygonal cross-section and formed in the above-described operating shaft and an intermediate wheel having a through hole for allowing the above-described operating shaft to pass therethrough, engaging on at least one surface with the above-described bulged portion in an inner circumferential surface of the above-described through hole and engaging with the above-described internal rotational ring in its outer circumferential surface, wherein the engagement between the above-described bulged portion and the above-described intermediate wheel is released by pushing in the above-described operating shaft. 
   In this invention, under the lock condition of the internal rotational ring, the bulged portion of the above-described operating shaft and the intermediate wheel are separated from each other. When this lock is to be released to rotate the internal rotational ring, the stem is pinched and the stem is drawn out of the case by the fingers. Then, the operating shaft fixed to the stem is also shifted in the direction in which the stem is drawn out and accordingly the bulged portion formed on the operating shaft is also shifted. Here, the bulged portion that has the above-described polygonal shape is engaged with the inner surface of the through hole provided to the intermediate wheel while rotating the stem. Under this condition, when the stem is rotated by the fingers, the rotating shaft is also rotated and the bulged portion is also rotated accordingly. Then, the intermediate wheel engaging with this is also rotated by the external force from the engagement surface and the internal rotational ring is also rotated. Thus, the internal rotational ring may be adjusted by rotating the stem. Furthermore, when the internal rotational ring is to be locked, the stem that has been drawn out is pushed into the case. Then, the operating shaft is shifted in the direction in which the stem is drawn out and the engagement between the bulged portion of the operating shaft and the inner circumferential surface of the intermediate wheel is released. Thus, the clutch is separated and the malfunction of the internal rotational ring is prevented. 
   Note that, the above-described invention includes the case where the bulged portion has a conical shape, a truncated conical shape and any other polygonal shape and the engagement surface with the above-described intermediate wheel is disposed on the side where the above-described operating shaft is drawn out. In this case, when the internal rotational ring is to be released, the bulged portion of the above-described operating shaft is shifted in the direction in which the stem is drawn out by drawing out the stem. Then, the engagement portion between the bulged portion of the operating shaft and the intermediate wheel is sought by rotating the stem and these are engaged with each other. In this case, since the engagement surface with the intermediate wheel faces the side where the operating shaft is drawn, by the draw force of the above-described stem, the bulged portion is biased to the intermediate wheel by the force applied for drawing the above-described stem. Furthermore, when the operating shaft is shifted in the pushing-in direction by pushing in the stem, the bulged portion of the operating shaft is separated from the inner circumferential surface of the intermediate wheel by pushing in the stem. 
   Also, the wrist-portable equipment according to this invention is characterized in that the above-described clutch comprises: a bulged portion formed in the above-described operating shaft and made of a frictional material; and an intermediate wheel having a through hole for allowing the above-described operating shaft to pass therethrough and engaging with the above-described bulged portion in an inner circumferential surface of the above-described through hole, and engaging with the above-described internal rotational ring in its outer circumferential surface, wherein the engagement between the above-described bulged portion and the above-described intermediate wheel is released by pushing in the above-described operating shaft. 
   In this invention, under the lock condition of the internal rotational ring, the bulged portion of the above-described operating shaft and the intermediate wheel are separated from each other. When this lock is to be released to rotate the internal rotational ring, the stem is pinched and the stem is drawn out of the case by the fingers. Then, the operating shaft fixed to the stem is shifted in the direction in which the stem is drawn out together with the bulged portion. Under this condition, when the stem is rotated by the fingers, the rotating shaft is also rotated and the bulged portion is also rotated. Then, the intermediate wheel engaging with this is also rotated by the frictional force with the above-described bulged portion, and thus the internal rotational ring is also rotated. Thus, the internal rotational ring may be adjusted by rotating the stem. Furthermore, when the internal rotational ring is to be locked, the stem that has been drawn out is pushed into the case. Then, the operating shaft is also shifted in the direction in which the stem is drawn out and the engagement between the bulged portion of the operating shaft and the inner circumferential surface of the intermediate wheel is released. Thus, the clutch is separated and the malfunction of the internal rotational ring is prevented. 
   Note that, the above-described invention includes the case where the bulged portion has a conical shape, a truncated conical shape, a spherical shape and any other curved shape and the engagement surface with the above-described intermediate wheel is disposed on the side where the above-described operating shaft is drawn out. In this case, when the internal rotational ring is to be released, the bulged portion of the above-described operating shaft is shifted in the direction in which the stem is drawn out by the draw operation of the stem. In this case, since the engagement surface with the intermediate wheel faces the side at which the operating shaft is drawn out, the bulged portion is biased toward the intermediate wheel due to the force applied for drawing the above-described stem. Furthermore, when the operating shaft is shifted in the pushing-in direction by pushing in the stem, the bulged portion of the operating shaft is separated from the inner circumferential surface of the intermediate wheel by the push-in operation of the stem. 
   Also, the wrist-portable watch of this invention is characterized by further comprising a fastening means for fastening the above-described stem to the above-described case when the above-described operating shaft is being pushed in. 
   In this invention, when pushing in the above-described shaft, the stem may be fixed to the case by the above-described fastening means. Accordingly, since drawing out of the stem may be further restricted in the state where the above-described clutch is being separated, it is possible to completely prevent malfunction of the internal rotational ring. 
   Also, the wrist-portable equipment according to this invention is characterized by further comprising a cushion made of elastic system material disposed on the side surface of the internal rotational ring and being biased toward the inner wall of the case. According to this invention, the cushion provided on the side surface of the internal rotational ring is biased to the inner wall of the case to thereby prevent any rattling upon the rotation of the internal rotational ring. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred form of the present invention is illustrated in the accompanying drawings in which: 
       FIG. 1  is a cross-sectional view showing a wrist-portable equipment that is a mode of embodiment of this invention; 
       FIG. 2  is a cross-sectional view showing the wrist-portable equipment that is the mode of embodiment of this invention; 
       FIG. 3  is a perspective view showing a clutch portion of the wrist-portable equipment; 
       FIGS. 4   4 A– 4 B are a plan view and a side elevational cross-sectional view, respectively, showing an intermediate wheel; 
       FIGS. 5A–5B  are a frontal view and a side elevation view, respectively showing an operating shaft; 
       FIG. 6  is across-sectional view showing a modification example of the wrist-portable equipment shown in  FIG. 1 ; 
       FIG. 7  is a cross-sectional view showing the modification example of the wrist-portable equipment shown in  FIG. 1 ; 
       FIG. 8  is a plan view showing a conventional wrist-portable equipment; and 
       FIG. 9  is a side elevational cross-sectional view showing a primary part of the conventional wrist-portable equipment shown in  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention will now be described in detail with reference to the accompanying drawings. It is understood that the present invention is not limited to the embodiments described. The structural elements of the embodiments described below may include those to which design alterations may typically be performed by the person skilled in the art. 
     FIGS. 1 and 2  are side elevational cross-sectional views showing the primary part and its vicinity of a wrist-wearable apparatus in the form of a wristwatch  1  in accordance with an embodiment of this invention.  FIG. 1  shows a state where a scale ring  103 , as an internal rotational ring, is locked and  FIG. 2  shows a state where the above-described lock is released.  FIG. 3  is an enlarged perspective view showing a clutch  2  of the wristwatch  1  described in  FIGS. 1 and 2 .  FIGS. 4   4 A– 4 B are a plan view and a side elevational cross-sectional view, respectively showing an intermediate wheel  3  described in  FIG. 3 .  FIGS. 5A–5B  are a frontal view and a side elevational view respectively, showing an operation or operating shaft  4  described in  FIG. 3 . Note that, in  FIGS. 1 to 5 , the same reference numerals are used to indicate the same elements as those of the above-described conventional wristwatch  100  and further explanation therefor will be omitted. 
   In  FIG. 1 , a stem  5  made of metal material and provided to the wrist watch  1  has a cup-shaped outer shell  6  and a cylindrical shaft  8  formed integrally with a bottom portion  7  of the above-described outer shell. A cylindrical operating shaft  4  made of metal material and having a diameter that is substantially half that of this shaft  8  is screwed and mounted coaxially with a rotary shaft of the stem  5  at a tip end of the shaft  8  of the above-described stem  5 . This operating shaft  4  has a bulged portion  11  having a regular octagonal cross-section in the vicinity of its tip end portion  10  (see  FIG. 5 ). A step between this bulged portion  11  and a cylindrical side surface portion  12  is smoothened by a gently tapered slant surface  13 . The above-described operating shaft  4  and the shaft  8  of the stem  5  are inserted into a tubular member comprised of a metal pipe  14  fixed and disposed through a watch case  101 . This pipe  14  and the shaft  8  of the above-described stem  5  are kept in a gap fitting relation. 
   Accordingly, the shaft  8  of the stem  5  may be rotated freely to the pipe  14  for enabling the push-in operation or the draw operation. A tip end portion  10  of the operating shaft  4  inserted into the pipe  14  is located in the interior of the watch case  101  through this pipe  14 . An annular intermediate wheel  3  made of metal material is fitted around the tip end portion  10  of the operating shaft  4 . Note that, in order to prevent the situation in which the operation shaft  4  is pulled apart from the intermediate wheel  3  by the draw operation of the stem  5 , the stop ring  15  is fitted around at the tip end portion  10  of the operating shaft  4 . The inner circumferential surface of the intermediate wheel  3  has a regular octagonal shape that may engage with the bulge portion  11  of the above-described operating shaft  4  in a gap fitting manner (see  FIG. 3 ). Accordingly, the intermediate wheel  3  is engaged with the bulged portion  11  of the above-described operating shaft  4  but not engaged with the cylindrical its surface portion  12 . The intermediate wheel  3  and the bulged portion  11  of the operating shaft  4  form a clutch assembly for transmitting rotation of the operating shaft  4  to the scale ring  103 . Also, the intermediate wheel  3  has a hook-shaped engagement portion  16  on its, top surface and, at this engagement portion  16 , is engaged with an engagement piece  17  formed at an end portion of the above-described pipe  14  and held rotatably. 
   On the other hand, the scale ring  103  provided within the watch case  101  has a rack  116  on its back surface circumferential portion  115 . This rack  116  is engaged with teeth  18  of the above-described intermediate wheel  3 . Thus the intermediate wheel  3  and teeth  18  constitute a gear wheel. Note that, an annular member  118  provided on a bottom surface portion  115  of the scale ring  103  is a cushion  118  made of a rubber-like material for preventing any displacement of the scale ring  103  upon the rotation. Also, an annular member  119  provided on an outer circumferential surface of the operating shaft  4  is an annular waterproof packing  119  made of rubber-like material for sealing a gap between the operating shaft  4  and the pipe  4 . 
   Also, in this wristwatch  1 , the stem  5  has a screw groove  19  on the inner wall surface of its cup-shaped outer shell  6 . The pipe  14  has screw crests  20  at an end portion projecting from the watch case  101 . This screw groove  19  is fitted with the screw crests  20  of the pipe  14  so that the stem  5  may be fixed to the watch case  101 . Also, these screw grooves  19  and screw crests  20  are cut into such a width that the stem  5  may be fixed or released before the bulged portion  11  of the operating shaft  4  and the intermediate wheel  3  are fitted with each other.  FIG. 1  is a side elevational cross-sectional view showing the fixed state and  FIG. 2  is a side elevational cross-sectional view showing the released state. On the other hand, a coil spring  21  is assembled into the interior of the pipe  14  while being kept in the elastically compressed condition. This coil spring  21  biases its one end portion to the engagement piece  17  at the tip end of the pipe  14  and the other end portion to a tip end portion of the shaft  8  of the stem  5 , and works in a direction in which the stem  5  is drawn out from the watch case  101 . 
   In  FIG. 1 , the stem  5  is kept under the fixed condition by the screw structure  19 ,  20  to the pipe  14 . Under this condition, the operating shaft  4  passes through the intermediate wheel  3  before its bulged portion  11  (i.e., the operating shaft  4  is in a pushed-in position). Accordingly, in the same drawing, since the stem  5  and the scale ring  103  are separated from each other, even if the stem  5  is rotated, the scale ring  103  is not rotated. Also, since the stem  5  per se is firmly fixed by means of the screw, even if the watch is brought into contact with the body or the like when the watch is worn, the stem  5  is not easily rotated. 
   When the scale ring  103  is to be adjusted, the outer sheet  6  of the stem  5  is pinched by the fingers and is rotated in a direction in which the screws  19 ,  20  are removed. Then, the screws  19 ,  20  are disengaged before the bulged portion  11  of the operating shaft  4  is fitted with the intermediate wheel  3 . subsequently, the stem  5  is drawn to from the watch case  101  while seeking by the fingertips so that the bulged portion  11  of the operating shaft  4  is fitted with the intermediate wheel  3  (i.e., the operating shaft is in a drawn-out position). Note that, at this time, the coil spring  21  works in a direction in which the stem  5  is drawn from the watch case  101 . Accordingly, the stem  5  is only sought while being lightly rotated to fit the bulged portion  11  of the operating shaft  4  in the intermediate wheel  3 . When the bulged portion  11  of the operating shaft  4  in the intermediate wheel  3 . When the bulged portion  11  is fitted in the intermediate wheel  3 , the stem  5  is rotated in the axial direction. Then, the operating shaft  4  is also rotated, and the intermediate wheel  3  is rotated together with this. Then, the rack  116  of the scale ring  103  is fed by means of the teeth  18  of the intermediate wheel  3  and the scale ring  103  is rotated (see  FIG. 2 ). Thus, it is possible to adjust the scale ring  103  to a desired position while watching the scale ring  103  through the glass  112  of the watch by the stem  5 . 
   Furthermore, when the scale ring  103  is to be locked, the stem  5  is pushed into the watch case  101  straightly without any rotation from this condition. Then, the bulged portion  11  of the operating shaft  4  is removed from the intermediate wheel  3  without any feed of the rack  116  of the scale ring. The screw groove  19  of the stem  5  is screwed and fitted with the screw crests  20  of the pipe  14  while being pushed into the watch case  101  and fixed. 
   According to this wristwatch  1 , in the mounted condition of the watch, the stem  5  may be fixed to the watch case  101  by the screw structure  19 ,  20 . Under this condition, even if the watch is brought into contact with the body or the like, there is no fear that the stem  5  would be drawn out of the watch case  101 . Also, under the condition that the stem  5  is also fixed to the watch case  101 , the operating shaft  4  and the intermediate wheel  3  are separated from each other (see  FIG. 1 ). Accordingly, under this condition, there is no fear of displacement of the scale ring  103 . Thus, according to this wristwatch  1 , it is possible to effectively prevent the malfunction of the scale ring  103 . Note that, in the wristwatch  1  according to this mode of embodiment, the shaft  8  of the stem  5  is a discrete part from the operating shaft  4  but these may be formed integrally with each other as in the modification example to be described later (see  FIG. 6 ). 
   Also, the inner circumferential surface shape of the intermediate wheel  3  and the bulged portion  11  of the above-described operating shaft  4  are not limited to the regular octagonal shape as described above. Also, the shape of the bulged portion  11  of the above-described operating shaft  4  is not limited to the angular post shape but may be an angular conical shape, a truncated angular conical shape, a conical shape, a truncated conical shape or any other tapered shape. Also, the materials of the bulged portion  11  of the above-described operating shaft  4  and the intermediate wheel  3  are not limited to the metal material but may be rubber-like material or any other frictional material. 
   Also, in the mode of this embodiment, the structure of direct engagement of the intermediate wheel  3  and the rack  116  of the scale ring  103  is taken but it is possible to arrange one or more discrete gears (not shown) in the midway of these and to splice the intermediate gear  3  and the rack  116  of the scale ring  103  with each other. Also, in the mode of this embodiment, the rack  116  of the scale ring  103  is formed on the back surface circumferential edge portion of the scale ring  103 . However, the structure is not limited thereto but the rack  116  may be formed on a side surface portion or a top surface portion. 
   Furthermore, in the mode of this embodiment, the cushion  118  of the above-described internal rotational ring is installed between the bottom surface portion of the scale ring  103  and the clockface  102  but the invention is not limited thereto. It is possible to install the cushion  118  between the side surface portion  114  of the scale ring  103  and the inner wall of the watch case  101  (see  FIG. 6 ). 
   Also, the fastening structure of the stem  5  is not limited to the above-described screw structure  19 ,  20  but may be a structure with a bayonet structure (not shown). Also, a discrete stop screw (not shown) is provided to the stem  5  separately from the above-described screw structure  19 ,  20  so that the stem  5  may be fixed by means of this stop screw. The reason for this is that, if it may prevent the draw operation of the stem  5  due to the unintended operation, the malfunction of the scale ring  103  may be prevented. Also, the structure is not limited to the case where the coil spring  21  is provided within the pipe  14  but the coil spring  21  may be installed within the outer shell  7  of the stem  5  (see  FIGS. 6  and  7 ). 
     FIGS. 6 and 7  are side elevation cross-sectional view showing a modification example of a wristwatch  1  in accordance with the mode of the embodiment described in  FIGS. 1 to 5 .  FIG. 6  shows the locked state of the scale ring  103  and  FIG. 7  shows the released state thereof, respectively. Note that, in  FIGS. 6 and 7 , the same reference numerals are used to indicate the same elements as those in the above-described prior art and the mode of embodiment and the explanation therefor will be omitted. 
   In  FIGS. 6 and 7 , the wristwatch  22  has the stem  5  on the side surface of the watch case  101  and has the scale ring  103  in the interior of the watch case  101 . This stem  5  is made of metal material and has a cup-shaped outer shell  7 . Also, a cylindrical shaft  8  is formed integrally with an inner bottom surface portion of the outer shell  7 . Furthermore, a cylindrical operating shaft  23  having a diameter that is substantially half of that of this shaft  8  is formed integrally with the tip end portion of this shaft  8 . Also, the wristwatch  22  has a pipe  14  fixed and provided passing through the watch case  101  from the side surface direction. The shaft  8  of the stem and the operating shaft  23  are inserted into the pipe  14 . The tip end of the operating shaft  23  is introduced into the interior of the watch case  101 , passing through the pipe  14 . 
   The shaft  8  of the stem  5  and the pipe  14  are kept under the gap fitting condition with each other. The stem  5  may perform the rotational operation, the draw operation and the push-in operation to the pipe  14  as desired. Also, a bevel gear  24  made of metal material is fitted in the tip end portion of the operating shaft  23 , with its engagement portion  26  in the draw direction of the operating shaft  23  and fixed by means of a stop ring  15  made of metal material. On the other hand, a rack  116  engaging with the above-described bevel gear  24  is formed in the back surface circumferential edge portion of the scale ring  103 . Note that, an annular water-proof packing  119  made of rubber-like material is provided on the outer circumferential surface of the shaft  8  of the stem  5 . Also, an annular cushion  25  made of rubber-like material for preventing any displacement upon the rotation is provided on a side surface portion  114  and a bottom surface portion  113  of the scale ring  103 . 
   In the wristwatch  22  described in  FIG. 6 , since the stem  5  is fixed to the watch case  101  by means of the screw structure  19 ,  20  and the bevel gear  24  and the rack  116  are kept under the separated condition from each other, the scale ring  103  is not rotated under this condition. Here, when the scale ring  103  is to be adjusted, the stem  5  is pinched and rotated by the fingers to thereby disengage the screw structure  19 ,  20  and separate from the pipe  14 . Then, the stem  5  is drawn out of the watch case  101  so that the operating shaft  23  is shifted in the draw direction. Then, the bevel gear  24  fixed to the tip end of the operating shaft  23  is also shifted to engage with the rack  116  of the scale ring  103  (see  FIG. 7 ). Under this condition, when the stem  5  is rotated, the bevel gear  24  is also rotated, the rack  116  is fed, and the scale ring  103  is also rotated. Thus, it is possible to adjust the scale ring  103  to a desired position while watching the scale ring  103  through the glass  112  of the watch. 
   According this wristwatch  1 , under the mounted condition of the watch, the stem  5  is fixed to the watch case  101  by the screw structure  19 ,  20  and the operating shaft  23  and the intermediate wheel  3  are separated from each other (see  FIG. 1 ). Accordingly, even if the watch is brought into contact with the body or the like, the stem  5  would not be readily rotated. Also, even if the stem is erroneously rotated, there is no displacement in position of the scale ring  103 . Thus, according to this wristwatch  22 , it is possible to effectively prevent the malfunction of the scale ring  103 . Also, the rotational transmission means to the scale ring  103  is formed by a bevel gear  24 , the engagement surface of the gear is directed in the draw direction of the stem  5 . Accordingly, the separation operation from, and the engagement operation with the rack  116  may be performed more easily than those of the post-shaped gear (not shown). 
   Note that, in the wristwatch  22  that is the present modification example, the bevel gear  24  and the rack  116  are used as the engagement means with the scale ring  103  but these may be frictional members having conical shapes or truncated conical shapes. 
   As described above, according to the wrist-portable equipment that is this invention, since under the mounted condition of the instrument, the stem and the internal rotational ring may be separated from each other at the clutch, it is possible to effectively prevent the malfunction of the internal rotational ring caused by the contact between the stem and the body or the like. 
   Also, according to the wrist-portable equipment that is this invention, since the bulged portion of the operating shaft has a polygonal cross-section and is engaged on at least one surface with the inner circumferential surface of the intermediate wheel, the bulged portion is engaged firmly with the inner circumferential surface of the intermediate wheel also in the case where the operating shaft is made of non-frictional material such as metal material or the like. 
   Also, according to the wrist-portable equipment that is this invention, since the bulged portion of the operating shaft is formed of frictional material, it is unnecessary to seek the engagement surface of the clutch by rotating the stem for bringing this bulged portion into contact with the inner circumferential surface of the intermediate wheel. Thus, it is possible to release the lock of the stem with ease. 
   Also, according to the wrist-portable equipment that is this invention, since the stem may be fixed to the case, it is possible to prevent the situation where the stem is erroneously drawn out under the condition that the internal rotational ring is locked. Thus, it is possible to completely prevent the malfunction of the internal rotational ring. 
   Also, according to the wrist-portable equipment that is this invention, since the cushion member is installed also on the side surface of the internal rotational ring, it is possible to prevent the displacement upon the rotation of the internal rotational ring more effectively than in the case of the conventional wrist-portable equipment.