Patent Publication Number: US-11390111-B2

Title: Writing implement

Description:
FIELD OF THE INVENTION 
     The present invention relates to a writing implement. 
     BACKGROUND ART 
     A rotation-type writing implement in which a head crown is rotated with respect to a barrel about an axis of the barrel so as to project/retract a writing body supported in the barrel from/into a front end opening of the barrel has been conventionally known (JP2007-320209A). Since a smooth projecting/retracting motion can be realized by decreasing a frictional resistance of an inside rotation mechanism, such a writing implement has excellent operation feeling. On the other hand, the writing body of a rotation-type writing implement is projected/retracted generally by, while holding the barrel by one hand, holding the head crown by the other hand and by relatively rotating the head crown with respect to the barrel about the axis. Thus, a quick projecting/retracting operation is difficult, and it takes time for the projecting/retracting operation. Thus, there is a room for improving operability. 
     On the other hand, a knock-type writing implement in which, by pushing forward a knock member which projects outside from a rear end opening of the barrel, with respect to a barrel, for example, a writing body supported in the barrel is projected from and retracted into a front end opening of the barrel. Since the projecting/retracting operation can be performed by one hand, the knock-type writing implement can be quickly operated. However, since the writing body is retracted into the barrel with momentum, the writing body may experience a large impact. In addition, click-clack noises may occur upon knocking. Thus, there is a room for improving operation feeling. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above circumstances. Namely, the object of the present invention is to provide a writing implement excellent in both operability and operation feeling. 
     A writing implement according to the present invention comprises: 
     a barrel; 
     a writing body supported by the barrel so as to be relatively movable with respect to the barrel in an axial direction thereof, whereby the writing body is projected from and retracted into a front end of the barrel; 
     a rotation member disposed in the barrel so as to be relatively rotatable with respect to the barrel about an axis thereof, the rotation member being provided with a groove or a slit that helically extends about the axis; and 
     a pressing unit having a moving unit that moves in the groove or the slit, the pressing unit being relatively movable with respect to the barrel in the axial direction, while its relative rotation about the axis being restricted; 
     wherein the pressing unit can be pressed with respect to the barrel, from outside the barrel. 
     The rotation member can be rotated from outside the barrel; 
     when the rotation member is relatively rotated with respect to the barrel about the axis, the moving unit of the pressing unit may be relatively moved with respect to the barrel in the axial direction; and 
     when the pressing unit is pressed forward with respect to the barrel, the rotation member may be relatively rotated with respect to the barrel about the axis. 
     The above writing implement may further comprise a braking unit that decelerates a rotation speed of the rotation member when the rotation member relatively rotates with respect to the barrel about the axis. 
     Alternatively, the above writing implement may further comprises a braking unit having a contact member that is in contact with the rotation member, and urging means that urges the contact member with respect to the barrel in the axial direction so as to bear the contact member against the rotation member. 
     In addition, the urging means may be disposed in front of the rotation member so as to bear the contact member against the rotation member from the front side. 
     In the above writing implement, 
     the rotation member may have a front wall and a rear wall which extend opposite to each other so as to define the groove or the slit; and 
     the front wall may have a bulge, which bulges rearward, near a front end of the groove or the slit. 
     Since the present invention enables a simple projecting/retracting operation by one hand and a quiet and smooth projecting/retracting operation, a writing implement excellent both in operability and operation feeling can be provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic longitudinal sectional view showing a writing implement according to one embodiment of the present invention. 
         FIG. 2  is a schematic elevational view showing an inner tube of the writing implement of  FIG. 1 . 
         FIG. 3  is a schematic longitudinal sectional view showing a rotation member of the writing implement of  FIG. 1 . 
         FIG. 4  is a schematic developed view of the rotation member, which is cut along the line C of  FIG. 3 . 
         FIG. 5A  is an enlarged view showing a part near a front end of a front wall of the rotation member shown in  FIG. 3 . 
         FIG. 5B  is an enlarged view showing a part near a front end of a rear wall of the rotation member shown in  FIG. 3 . 
         FIG. 6A  is a view for describing an operation of the writing implement of  FIG. 1 , showing a state in which a writing body is retracted in a barrel. 
         FIG. 6B  is a view for describing the operation of the writing implement of  FIG. 1 , showing a state in which the writing body is relatively moved forward with respect to the barrel. 
         FIG. 6C  is a view for describing the operation of the writing implement of  FIG. 1 , showing a state in which the writing body is projected from the barrel. 
         FIG. 6D  is a view for describing the operation of the writing implement of  FIG. 1 , showing a state in which the writing body is relatively moved rearward with respect to the barrel. 
         FIG. 7  is a schematic longitudinal sectional view of a writing implement according to a modification example of  FIG. 1 , showing a state in which a writing body is retracted in a barrel. 
         FIG. 8  is a schematic longitudinal sectional view of the writing implement according to the modification example of  FIG. 1 , showing a state in which the writing body is projected from the barrel. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     One embodiment of the present invention is described in detail below, with reference to the attached drawings. 
       FIG. 1  is a schematic longitudinal sectional view showing a writing implement  100  according to one embodiment of the present invention. Note that a writing body  20  is shown in a side view. In addition,  FIG. 2  is a schematic elevational view showing an inner tube  11  of the writing implement  100  of  FIG. 1 .  FIG. 3  is a schematic longitudinal view of a rotation member  30  of the writing implement  100  of  FIG. 1 .  FIG. 4  is a schematic developed view showing the rotation member  30 , which is cut along the line C of  FIG. 3 . 
     As shown in  FIGS. 1 and 3 , the writing implement  100  has a barrel  10 , a writing body  20  supported by the barrel  10 , a rotation member  30  disposed in the barrel  10  and provided with a slit  33   s  that helically extends about an axis L, and a pressing unit  40  having a moving unit  41  that moves in the slit  33   s . In the example shown in  FIG. 1 , the writing implement  100  is a fountain pen. However, not limited thereto, the writing implement  100  may be various writing implements such as a ball-point pen, a mechanical pencil, a marker, etc. As shown in  FIG. 1 , the writing body  20  is supported by the barrel  10  so as to be relatively movable with respect to the barrel  10  in an axial direction da thereof. A pen point  21  is configured to be projected from and retracted into an opening  10   a  delimited in a front end of the barrel  10 . 
     As shown in  FIG. 1 , the barrel  10  has a barrel body  13 , and an inside tube  11  disposed inside the barrel body  13 . As shown in  FIG. 2 , a slot  12  extending along the axial direction da is formed in the inside tube  11 .  FIG. 2  shows the inside shaft  11  of  FIG. 1  seen from above. As shown in  FIG. 1 , the slot  12  has a width capable of accommodating the moving unit  41  of the pressing unit  40 , and is symmetrically provided with respect to an axis L. 
     As shown in  FIGS. 3 and 4 , the rotation member  30  is a cylindrical member disposed in the barrel  10  so as to be relatively rotatable with respect to the barrel  10  about its axis L. The rotation member  30  has a cylindrical rotation member body  33 , a front wall  31 , and a rear wall  32 . The front wall  31  and the rear wall  32  extend opposite to each other so as to define two slits  33   s . The two slits  33   s  extend helically about the axis L (see  FIG. 1 ) with a 180° phase difference. As shown in  FIG. 4 , each slit  33   s  extends forward (left in  FIG. 4 ) from a position near a rear end  33   r  of the rotation member body  33  at a substantially uniform inclination. 
     On the other hand, the inclination of each slit  33   s  changes at an area near a front end  33   f  of the rotation member body  33 .  FIG. 5A  is an enlarged view showing a part near a front end of the front wall  31  of the slit  33   s  of the rotation member  30  shown in  FIG. 3 . As shown in  FIG. 5A , the front wall  31  has a bulge  31   e , which bulges rearward (right in  FIG. 5A ), near a front end  33   sf  of the slit  33   s . As shown in  FIG. 5A , in the bulge  31   e , when seen from above, the front wall  31  has a shape in which a tangent line and a vector that goes rearward along the axial direction da always define an acute angle (0°&lt;θ1&lt;θ2&lt;90°). 
       FIG. 5B  is an enlarged view showing a part near a front end of the rear wall  32  of the rotation member  30  shown in  FIG. 3 . As shown in  FIG. 5B , a detent portion  32   e  bulging forward is formed near the front end of the rear wall  32  of each slit  33   s . The rear wall  32  has a shape in which, when seen from above, an angle defined between a tangent line of the rear wall  32  and a vector that goes rearward along the axial direction da changes from an obtuse angle θ 3 , which is before the detent portion  32   e , to an acute angle θ 4 , which is after the detent portion  32   e.    
     Returning to  FIG. 1 , a relative rearward movement of the writing body  20  with respect to the barrel  10  is restricted because a rear end of the writing body  20  is in contact with the pressing unit  40 . The writing body  20  is urged rearward with respect to the barrel  10  by a coil spring  50 . As illustrated, the coil spring  50  is compressed between a barrel side locking portion  15 , which is provided on an inner surface of the barrel body  13 , and a writing-body side locking portion  22 , which is provided on the writing body  20  behind the barrel side locking portion  15 . 
     As shown in  FIG. 1 , the pressing unit  40  extends outside from a rear end of the barrel  10  and can be pressed forward from outside the barrel  10 . The pressing unit  40  is disposed in the inner tube  11  to pass through the rotation member  30  in the axial direction da and is relatively movable with respect to the barrel  10  in the axial direction da. The moving unit  41  of the pressing unit  40  passes radially through both the two slits  33   s  of the rotation member  30 , and both ends thereof are positioned in the slot  12  of the inner tube  11 . A rear end portion  35  of the rotation member  30  extends outside from the rear end of the inner tube  11 . A head crown  34  is attached to the rear end portion  35 . A relative forward movement of the head crown  34  with respect to the inner tube  11  is restricted because the head crown  34  is in contact with the rear end of the inner tube  11 . Thus, even when the rotation member  30  is pressed forward by the pressing unit  40 , the rotation member  30  does not relatively move forward with respect to the barrel  10  (inner tube  11 ). Further, although not shown, grease is applied between the pressing unit  40  and the rotation member  30 , and between the rotation member  30  and the inner tube  11 . 
     Next, an operation of the above writing implement  100  is described with reference to  FIGS. 6A to 6D . 
       FIGS. 6A to 6D  are views for describing an operation of the writing implement  100  of  FIG. 1 . In  FIGS. 6A to 6D , the writing body  20 , the rotation member  30  and the pressing unit  40  are pulled out from  FIG. 1 , the rotation member  30  is shown in a developed view, and the position of the slot  12  of the inner shaft  11  is overlapped.  FIG. 6A  shows a state in which the writing body  20  is retracted in the barrel  10 ,  FIG. 6B  shows a state in which the writing body  20  is relatively moved forward with respect to the barrel  10 ,  FIG. 6C  shows a state in which the writing body  20  projects from the barrel  10 , and  FIG. 6D  shows a state in which the writing body  20  is relatively moved rearward with respect to the barrel  10 . 
     Herein, as shown in  FIG. 6A , the state in which the pen point  21  of the writing body  20  is completely retracted in the barrel  10  is described as an initial state. In this initial state, the moving unit  41  of the pressing unit  40  is positioned at the respective rear ends of the slit  33   s  of the rotation member  30  and the slot  12  of the inner tube  11 . This state is maintained by the coil spring  50  which urges rearward the writing body  20  with respect to the barrel  10 . 
     In the writing implement  100 , when the pressing unit  40  is moved forward with respect to the barrel  10  with a force F (see  FIG. 6B ) from the state shown in  FIG. 6A , the moving unit  41  presses the front wall  31  of the rotation member  30 . Due to this pressing, the front wall  31  and the moving unit  41  are subjected to forces opposed to each other in a direction orthogonal to the inclination of the front wall  31 . Thus, these forces include a component in the axial direction da of the barrel  10 , and a component in a direction orthogonal to the axial direction da. Since the both ends of the moving unit  41  are positioned in the slot  12  of the inner tube  11 , relative rotation of the moving unit  41  with respect to the inner shaft  11  about the axis L is restricted. Thus, as shown in  FIG. 6B , the moving unit  41  relatively moves forward along the slot  12 , without relatively rotating with respect to the barrel  10 . As a result, when seen from behind, the rotation member  30  is relatively rotated clockwise with respect to the barrel  10 , and the writing body  20  is relatively moved forward with respect to the barrel  10  while compressing the coil spring  50 . In accordance with the relative rotation of the rotation member  30  with respect to the barrel  10 , the head crown  34  is relatively rotated with respect to the barrel  10  about the axis L (see  FIG. 6B ). 
     A force required for relatively moving forward the pressing unit  40  with respect to the barrel  10  is a resultant force of a counterforce received by the pressing unit  41  from the front wall  31  of the rotation member  30 , and an urging force by the coil spring  50 . Until the moving unit  41  of the pressing unit  40  reaches the bulge  31   e  of the rotation member  30 , the inclination of the front wall  31  of the rotation member  30  is constant. Thus, the counterforce received by the moving unit  41  from the front wall  31  of the rotation member  30  is substantially constant, irrespectively of the relative positional relationship between the rotation member  30  and the pressing unit  40 . On the other hand, the urging force by the coil spring  50  increases at a constant rate as the pressing unit  40  relatively moves forward with respect to the barrel  10 . Thus, the force required for relatively moving forward the pressing unit  40  with respect to the barrel  10  increases at a constant rate. 
     When the moving unit  41  of the pressing unit  40  has reached the bulge  31   e  of the rotation member  30 , the inclination of the front wall  31  of the rotation member  30  becomes steeper with respect to the axis L (see  FIG. 5 ). Thus, a ratio of a component of force that acts to relatively rotate the rotation member  30  with respect to the barrel  10  about the axis L, out of the force of the moving unit  40  that acts on the front wall  31  of the rotation member  30 , decreases. In other words, it is necessary to act a larger pressing force on the pressing unit in order to continuously relatively rotate the rotation member  30  with respect to the barrel  10  about the axis L. Namely, when the moving unit  41  of the pressing unit  40  has reached the bulge  31   e  of the rotation member  30 , a heavy operation feeling is provided to a user who presses the pressing unit  40 . 
     Then, when the moving unit  41  of the pressing unit  40  has got over an apex of the bulge  31   e  of the rotation member  30 , the inclination of the front wall  31  now becomes more gentle with respect to the axis L (see  FIG. 5A ). Thus, a ratio of the component of force that acts to relatively rotate the rotation member  30  with respect to the barrel  10  about the axis L, out of the force of the moving unit  40  that acts on the front wall  31  of the rotation member  30 , increases. In other words, it is sufficient to act a smaller pressing force on the pressing unit  40  in order to continuously relatively rotate the rotation member  30  with respect to the barrel  10  about the axis L. Namely, when the moving unit  41  of the pressing unit  40  has got over the apex of the bulge  31   e  of the rotation member  30 , a light operation feeling is provided to the user who presses the pressing unit  40 . Thus, immediately before the moving unit  41  of the pressing unit  40  is positioned at the front end  33   sf  of the slit  33   s , a click feeling is provided to the user. Further, during this operation, a quiet and smooth operation feeling is provided by the effect of the grease applied between the rotation member  30  and the inner shaft  11 . 
     Due to the click feeling, the user can perceive that the writing body  20  has been relatively moved up to the frontmost point with respect to the barrel  10 . Then, when the pressing force F acting on the pressing unit  40  is released, the writing body  20  is urged rearward with respect to the barrel  10  by the urging force of the coil spring  50 . Thus, the moving unit  41  of the pressing unit  40  is relatively moved rearward with respect to the barrel  10  so as to bear against the rear wall  32  of the rotation member  30  (see  FIG. 6C ). At this time, when seen from behind, the detent portion  32   e  of the rotation member is located at a position advanced clockwise from the moving unit  41  about the axis L. As described above, since a part of the detent portion  32   e  and the vector that goes rearward along the axial direction da define the obtuse angle θ 3  (see  FIG. 5B ), there is no possibility that the rotation member  30  is relatively rotated with respect to the barrel  10  about the axis L, even when the moving unit  41  presses rearward the rear wall  32  of the rotation member  30  by the urging force of the coil spring  50 . 
     By means of the above operation, the operation for exposing the writing body  20  from the front end of the barrel  10  is completed. Then, the user grips the barrel  10  and moves the barrel  10  as desired for writing, while the pen point  21  is in contact with a paper sheet. 
     After the writing, when seen from behind, the user relatively rotates counterclockwise the head crown  34  with respect to the barrel  10 . At this time, the rotation member  30  together with the head crown  34  is relatively rotated with respect to the barrel  10  about the axis L, so that the detent portion  32  of the rotation member  30  presses forward the moving unit  41  of the pressing unit  40  with respect to the barrel  10 . Thus, while the writing body  20  compresses the coil spring  50 , the moving unit  41  gets over the detent portion  32   e . After the moving unit  41  has got over the detent portion  32   e , the writing body  20  is relatively moved rearward with respect to the barrel  10  by the urging force of the coil spring  50  as a driving force, and the pressing unit  40  in contact with the writing body  20  is relatively moved rearward with respect to the barrel  10 . Thus, it is not necessary for the user to relatively rotate the head crown  34  counterclockwise continuously. During the relative movement of the pressing unit  40  with respect to the barrel  10 , the moving unit  41  relatively moves rearward with respect to the barrel  10  along the slot  12  of the inner shaft  11  (see  FIG. 6D ), while relatively rotating counterclockwise the rotation member  30  with respect to the barrel  10  when seen from behind. This relative movement continues until the moving unit  41  reaches the rear end  33   sr  of the slit  33   s . Thus, the initial state shown in  FIG. 6A  is restored. Also in the relative rearward movement of the pressing unit  40  with respect to the barrel  10 , a quiet and smooth operation feeling can be provided by the effect of the grease. 
     Note that, in the writing implement  100 , the pen point  21  of the writing body  20  can be projected from the barrel  10 , also by relatively rotating the head crown  34  with respect to the barrel  10  about the axis L. In this case, in the initial state shown in  FIG. 6A , when seen from behind, by relatively rotating clockwise the head crown  34  about the axis L with respect to the barrel  10 , the moving unit  41  moves forward in the slot  12  of the inner tube  11 , by a force received from the rear wall  32  of the rotation member  30 . Thus, the writing body  20  relatively moves forward with respect to the barrel  10  while compressing the coil spring  50 , so that the pen point  21  is gradually exposed from the barrel  10 . In this manner, when the writing body  20  is exposed from the front end of the barrel  10  by the rotational operation of the head crown  34 , the rear wall  32  of the rotation member  30  presses the moving unit  41 . Thus, in this case, differently from the aforementioned pressing operation of the pressing unit  40 , the interaction between the front wall  31  of the rotation member  30  and the moving unit  41  does not occur. 
     Then, immediately before the moving unit  41  of the pressing unit  40  reaches the front end  33   sf  of the slit  33   s  of the rotation member  30 , the moving unit  41  gets over the detent portion  32   e . Thus, as described above, there is no possibility that the moving unit  41  relatively moves rearward with respect to the barrel  10 , even when the moving unit  41  presses rearward the rear wall  32  of the rotation member  30  by the urging force of the coil spring  50 . Namely, the state in which the pen point  21  of the writing body  20  is exposed from the barrel  10  can be stably maintained. Since a procedure for retracting the pen point  21  of the writing body  20  into the barrel  10  after writing is the same as the procedure described with reference to  FIGS. 6C and 6D , description thereof is omitted here. 
     According to the aforementioned writing implement  100 , by pressing forward the pressing unit  40  with respect to the barrel  10 , the pen point  21  of the writing body  20  is exposed from the barrel  10 , while the rotation member  30  is relatively rotated with respect to the barrel  10  about the axis L smoothly. Namely, according to the present invention, since the writing body  20  can be quietly and smoothly projected from and retracted into the barrel  10  by a simple one-hand operation, the writing implement  100  excellent in both operability and operation feeling can be provided. 
     In addition, the rotation member  30  can be rotated outside from the barrel  10  through the head crown  34 . Thus, by relatively rotating the rotation member  30  with respect to the barrel  10  about the axis L, the moving unit  41  of the pressing unit  40  is relatively moved with respect to the barrel  10  in the axial direction da. By pressing forward the pressing unit  40  with respect to the barrel  10 , the rotation member  30  is relatively rotated with respect to the barrel  10  about the axis L. Thus, either by means of the forward pressing operation of the pressing unit  40  with respect to the barrel  10 , or by the rotational operation of the rotation member  30  about the axis L through the head crown  34 , the pen point  21  of the writing body  20  can be exposed from the barrel  10 . 
     Further, the rotation member  30  has the front wall  31  and the rear wall  32  which extend opposite to each other so as to define the slit  33   s , and the front wall  31  has the bulge  31   e , which bulges rearward, near the front end  33   sf  of the slit  33   s . Thus, when the operation for pushing forward the pressing unit  40  with respect to the barrel  10  so as to expose the pen point  21  of the writing body  20  from the barrel  10  is completed, a suitable click feeling can be provided to a user. 
     Next, a modification example of the writing implement  100  of  FIG. 1  is described. 
       FIGS. 7 and 8  are schematic longitudinal sectional views showing a writing implement  200  according to a modification example of  FIG. 1 .  FIG. 7  shows a state in which the writing body  20  is retracted in the barrel  10 , and  FIG. 8  shows a state in which the writing body  20  is projected from the barrel  10 . 
     As shown in  FIG. 7 , the writing implement  200  differs from the writing implement  100  shown in  FIG. 1  in that it further comprises a braking unit  260  that decelerates a rotation speed of the rotation member  30  when the rotation member  30  relatively rotates with respect to the barrel  10  about the axis L. The braking unit  260  has a contact member  262  that is in contact with the rotation member  30 , and urging means  261  that urges the contact member  262  with respect to the barrel  10  in the axial direction da so as to bear the contact member  262  against the rotation member  30 . A relative rotation of the contact member  262  with respect to the barrel  10  about the axis L is restricted. In the example shown in  FIG. 7 , the urging means  261  is disposed in a compressed state between the barrel  10  (barrel body  13 ) and the contact member  262 . Namely, the urging means  261  is disposed in front of the rotation member  30  so as to bear the contact member  262  against the rotation member  30  from the front side. The remaining structure is substantially the same as that of the writing implement  100  shown in  FIG. 1 . Thus, in  FIGS. 7 and 8 , the same symbol is given to a constituent element common to that of the writing implement  100  of  FIG. 1 , and detailed description thereof is omitted. 
     In such a writing implement  200 , a main operation for projecting/retracting the writing body  20  from/into the barrel  10  is common to the operation of the writing implement  100  described with reference to  FIGS. 6A to 6D . However, in the writing implement  200 , a rotation speed of the relative rotation of the rotation member  30  with respect to the barrel  10  about the axis L is decelerated by a frictional force acting on a contact part between the rotation member  30  and the contact member  262 . Namely, upon completion of writing with the writing implement  200 , when the head crown  34  is relatively rotated counterclockwise seen from behind by a user with respect to the barrel  10 , the rotation member  30  is relatively rotated with respect to the barrel  10  about the axis L, in accordance with the relative rotation. When the moving unit  41  of the pressing unit  40  has got over the detent portion  32   e  of the rotation member  30 , as described above, the writing body  20  is relatively moved rearward with respect to the barrel  10  by the urging force of the coil spring  50 . Thus, the pressing unit  40  in contact with the writing body  20  relatively moves rearward with respect to the barrel  10 , while relatively rotating the rotation member  30  with respect to the barrel  10  about the axis L. During this relative movement, due to the presence of the braking unit  260 , the rotation member  30  and the head crown  34  attached to the rear end portion  35  of the rotation member  30  are relatively rotated with respect to the barrel  10  about the axis L comparatively slowly. Thus, the pressing unit  40  returns to the initial state shown in  FIG. 7  comparatively slowly. 
     According to the aforementioned writing implement  200 , in addition to the same effect as that of the writing implement  100 , when the writing body  20  is projected from and retracted into the barrel  10 , a more quiet and smooth operation feeling than that of the writing implement  100  can be provided due to the presence of the braking unit  260 . Further, when the writing body  20  is projected from and retracted into the barrel  10 , in particular, when the writing body  20  is retracted into the barrel  10  so that the moving unit  41  comes into contact with the rear end  33   sr  of the slit  33   s , it can be effectively prevented that the writing body may experience a large impact, whereby risk in which ink spatters from the pen point  21  can be reduced. 
     In addition, when the writing body  20  is retracted into the barrel  10 , a projecting motion of the pressing unit  40  is carried out at the rear end of the barrel  10 , correspondingly to the retracting motion of the pen point  21  performed in front of the barrel  10 . The projecting motion is performed at a low speed due to the presence of the braking unit  260 . In accordance therewith, the head crown  34  disposed behind the barrel  10  is rotated slowly. Thus, the motions of the both members can be easily perceived visually, so that a user can easily feel a functional character. Further, an outer circumferential surface of the head crown  34  exposed from the barrel  10  may be subjected to a knurling process or a diamond-cutting process. In this case, during the operation (rotation) of the crown head  34 , an ornamental effect can be obtained by the crown head  34  that reflects light in various directions. In addition, such a process also serves as non-slip means, the rotational operation is facilitated. Moreover, even when the grease applied between the pressing unit  40  and the rotation member  30  and between the rotation member  30  and the inner tube  11  deteriorates because of long-term use, a quiet and smooth operation feeling can be maintained. In addition, even in a case where no grease is applied, a quiet and smooth operation can be provided. 
     In addition, the braking unit  260  has the contact member  262  that is in contact with the rotation member  30 , and the urging means  261  that urges the contact member  262  with respect to the barrel  10  in the axial direction da so as to bear the contact member  262  against the rotation member  30 . Thus, since the contact member  262  bears against the rotation member  30  at a constant pressing force, the rotation member  30  can stably receive a constant frictional force. 
     Furthermore, in the writing implement  200 , since the urging means  261  is disposed in front of the rotation member  30  so as to bear the contact member  262  against the rotation member  30  from the front side, a space for the braking unit  260  can be ensured more easily in front of the rotation member  30  than behind thereof, whereby a degree of freedom in design of the braking unit  260  is high. That is to say, a material of the contact member  262  and a spring constant of the urging means  261 , which determine a frictional force acting on the rotation member  30 , can be easily set as desired. 
     Note that the braking unit  260  may be disposed behind the rotation member  30 . Namely, the urging means  261  may be disposed behind the rotation member  30  so as to bear the contact member  262  against the rotation member  30  from the rear side. Also in this case, the same effect can be achieved. In addition, the braking unit  260  may be disposed laterally to the rotation member  30 . Namely, the urging means  261  may be disposed laterally to the rotation member  30  so as to bear the contact member  262  against the rotation member  30  from the lateral side. Further, the braking unit  260  is not limited to the combination of the urging means  261  and the contact member  262 . For example, a member such as an O-ring made of rubber or elastomer, which can provide a desired frictional force, may be employed, and such a member may be disposed in a clearance between the barrel  10  and the rotation member  30 . 
     In addition, in the above description, the example of the writing implement  100  or  200  in which the slits  33   s  are formed by the front wall  31  and the rear wall  32  of the rotation member  30  is described. However, as long as the moving unit  41  can be guided, grooves or the like may be formed instead of the slits  33   s . Also in this case, the rotation member  30  can be relatively rotated with respect to the barrel  10  about the axis L suitably, by the moving unit  41  of the pressing unit  40 . 
     In addition, in the above description, the example in which the pressing unit  40  is projected rearward from the rear end of the barrel  10 . However, another example is possible in which a clip (not shown) disposed on a lateral surface of the barrel  10  (inner shaft  11 ) functions as a pressing unit as a so-called clip slide type. Alternatively, the writing implement may be of a side knock type in which an operation unit capable of being pushed in the radial direction of the barrel  10  is provided on the side surface of the barrel  10 . In this case, a suitable mechanism that converts a pushing force of the operation unit in the radial direction of the barrel  10  to a force in the axial direction da of the barrel  10  is employed.