Abstract:
A locking device for locking an opening-and-closing moving body in a stopped position includes a striker body disposed on one of a striking part of the opening-and-closing moving body and a struck part of a non-moving body hitting against the striking part of the moving body in the stopped position, and a catcher body disposed on the other of the striking part of the moving body and the struck part of the non-moving body. The catcher body includes an inner part with a receiving part for receiving the striker body, an outer part for holding the inner part, a forcing device for urging the inner part, and a damping device for damping the inner part. The forcing device urges the inner part to engage the outer part and stop when the inner part is situated in a forward position.

Description:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT 
   The invention relates to a locking device for locking an opening-and-closing moving body such as a sliding door or a drawer in a stopped position such as a completely closed position so as to stably maintain a stopped state. 
   Patent Document 1 has disclosed a shock-absorbing device for absorbing an impact when a sliding door is closed by inserting a dovetail-shaped part provided on a slider into a dovetail-shaped part provided on a receiving member while the sliding door is moving to a stopped position. 
   With such a shock-absorbing device, it is difficult to completely absorb an impact when the sliding door moves toward the closed direction at an excessive speed. Also, when the speed of movement is too small, the sliding door would stop before completely closed. 
   Patent Document 1: Japanese Patent Publication (Kokai) No. 08-21147 
   The problem that the invention attempts to solve resides in that the stopped state of an opening-and-closing moving body can be produced properly, and it can be maintained stably, regardless of the speed of movement of the opening-and-closing moving body toward the stopped position, and in addition, that the stopping can be accomplished gently. 
   Further objects and advantages of the invention will be apparent from the following description of the invention. 
   SUMMARY OF THE INVENTION 
   In order to solve said problem, in this invention, a locking device for locking opening-and-closing moving body in stopped position includes the following features (1) to (5).
     (1) The locking device includes a striker body which is provided on either a striking part of an opening-and-closing moving body which is struck against a struck part of a non-moving body in a stopped position or a struck part of the non-moving body, and a catcher body which is provided on the other of these;   (2) the catcher body includes an inner part which has a receiving part for the striker body, an outer part which holds the inner part to be capable of moving forward and backward and rotating around a longitudinal axis of the inner part, a forcing device which normally forces the inner part in the backward direction of drawing into the outer part, and a damping device which applies damping to the movement of the inner part in the backward direction by the forcing device;   (3) in the forward position of the inner part, by the forcing of the forcing device, a part of the inner part is caught on the outer part, and the backward movement of the inner part by the forcing is checked;   (4) the inner part is rotated by the striker body which enters the receiving part of the inner part in the forward position accompanying the movement of the opening-and-closing moving body toward the stopped position, and   (5) the striker body is locked in the receiving part by the rotation, and the checking of the backward movement of the inner part is released.   

   When the opening-and-closing moving body is moved toward the stopped position, the striker body enters the receiving part of the inner part of the catcher body. Accordingly, the inner part in the forward position is rotated. By this rotation, the striker body couples with the inner part. In addition, a backward movement of the inner part is allowed. Accordingly, the inner part in the forward position is moved in the backward direction by the forcing of the forcing device, and by the backward movement of the inner part, the striker body also is drawn into the depth of the catcher body. Accordingly, a state in which the striking part of the opening-and-closing moving body and the struck part of the non-moving body are mutually striking is produced compulsorily, and the state can be maintained stably. Even if the speed of the movement toward the stopped position of the opening-and-closing moving body is comparatively small, the opening-and-closing moving body can be moved assuredly up to the expected stopped position of the opening-and-closing moving body, in which the striking part and struck part are mutually striking by the coupling between the striker body and the inner part. In such a locking device, because it has the damping device which applies damping to the backward movement of the inner part by the forcing device, even if the speed of the movement of the opening-and-closing moving body toward the stopped position is comparatively large, this can be attenuated, and the striking part and struck part strike firmly without an impact noise. 
   In order to solve the problems, in the invention, a locking device for locking an opening-and-closing moving body in a stopped position includes the following features (1)–(8).
     (1) The locking device includes a striker body which is provided on either a striking part of an opening-and-closing moving body which is struck against a struck part of a non-moving body in a stopped position or a struck part of the non-moving body, and a catcher body which is provided on the other of these;   (2) the striker body includes a shaft part which extends along the direction of movement of the opening-and-closing moving body, and a locking projection which projects out sideways from the side of the shaft part;   (3) the catcher body includes an inner part which has a receiving part for the striker body, an outer part which holds the inner part to be capable of moving forward and backward and rotating around a longitudinal axis of the inner part, a forcing device which normally forces the inner part in the backward direction of drawing into the outer part, and a damping device which applies damping to the movement of the inner part in the backward direction by the forcing device;   (4) in the receiving part of the inner part, there is formed a catch groove which is formed of an entrance groove part which follows the receiving direction of the striker body, and a deep side groove part which is connected to the deep end of the entrance groove part and extends toward a direction intersecting the receiving direction while making a corner in the place of connection;   (5) in either of the inner part or the outer part, there is formed a lock groove which is formed of a straight groove part which follows the direction of movement of the inner part, and a front side groove part which is connected to the front end of the straight groove part and extends toward a direction intersecting the direction of movement while making a corner in the place of connection, and a lock projection which enters the lock groove is formed in the other of these;   (6) in the forward position of the inner part, the lock projection is caught in the front end groove part of the lock groove by the forcing of the forcing device;   (7) the locking projection of the striker body which enters the receiving part of the inner part in the forward position accompanying the movement of the opening-and-closing moving body toward the stopped position is pushed against the outer corner part of the corner of the catch groove and the inner part is rotated forward; and   (8) the locking projection is caught in the deep side groove part of the catch groove by the forward rotation, and the lock projection in the front side groove part of the lock groove enters the straight groove part.   

   When the opening-and-closing moving body is moved toward the stopped position, the striker body enters the receiving part of the inner part of the catcher body, and the locking projection of the striker body enters the catch groove. The locking projection of the striker body in the catch groove is pushed against the outer corner part of the corner of the catch groove, thereby rotating the inner part forward in the forward position. By this forward rotation, the locking projection of the striker body enters the deep side groove part of the catch groove, thereby engaging the striker body with the inner part. In addition, by this forward rotation, the lock projection of the inner part is removed from the front side groove part of the lock groove, and enters the straight groove part. Because the inner part in the forward position is normally forced in the backward direction by the forcing of the forcing device, the inner part is moved backward by the entering of the lock projection the straight groove part. By the backward movement of the inner part, the striker body also is drawn into the depth of the catcher body. Accordingly, a state in which the mutual striking between the striking part of the opening-and-closing moving body and the struck part of the non-moving body is produced compulsorily, and the state can be maintained stably. Even if the speed of the movement toward the stopped position of the opening-and-closing moving body is comparatively small, the opening-and-closing moving body can be moved assuredly up to the expected stopped position of the opening-and-closing moving body, in which the striking part and struck part are mutually striking by the coupling between the striker body and the inner part. In such s locking device, because it has a damping device which applies damping to the backward movement of the inner part by the forcing device, even if the speed of the movement toward the stopped position of the opening-and-closing moving body is comparatively large, this can be attenuated, and the striking part and struck part strike firmly without an impact noise. 
   Accompanying the movement of the inner part toward the forward position by operation of the opening-and-closing moving body to be moved toward the original position, in the stopped position with the locking projection of the striker body being caught in the deep side groove part of the catch groove of the inner part in the backward position, the lock projection is pushed against the outer corner part of the corner of the lock groove and the inner part is rotated in reverse. The locking projection is removed from the deep side groove part of the catch groove by this reverse rotation. 
   By moving the opening-and-closing moving body in the stopped position toward the original position, the lock projection of the inner part again enters the front side groove part of the lock groove whereby the inner part is restored to the forward position, and the state can be maintained. In addition, the coupling between the inner part and striker body is released whereby the striker can be removed from the receiving part of the inner part, and the state of maintaining the stopped position of the opening-and-closing moving body by the locking device can be released smoothly with one action. 
   On the side of the entrance of the entrance groove part of the catch groove on the receiving part of the inner part, there is formed a cam surface which is struck by the locking projection by striking the striker body on the inner part rotated forward and moved to the backward position by erroneous operation, and causes the inner part to rotate in reverse, so that the locking projection enters the catch groove. 
   If the opening-and-closing moving body is moved toward the stopped position from a state in which the inner part is erroneously moved backward, the locking projection of the striker body is struck on the cam surface, and the inner part is rotated in reverse. Accordingly, it is possible to make the locking projection of the striker body enter the catch groove. When the locking projection of the striker body enters the catch groove, the locking projection is pushed against the outer corner part of the corner of the catch groove, the inner part is rotated forward, the locking projection is caught in the deep side groove part of the catch groove, and a state being the same as when the striker body is received by the catcher body is produced correctly. 
   The locking projections are formed respectively on both the left and right sides of the striker body. In addition, catch grooves, lock grooves, and lock projections are formed respectively on one side and the other side of an imaginary plane including the central axial line of the inner part following the longitudinal direction of this inner part. 
   Accordingly, the inner part can be rotated forward smoothly accompanying the movement toward the stopped position of the opening-and-closing moving body. By moving the opening-and-closing moving body toward the original position from the stopped position of the opening-and-closing moving body having the striker body coupled with the inner part by this forward rotation, a state in which the inner part is restored to the forward position while smoothly rotating the inner part in reverse to release such coupling can be maintained. 
   The damping device comprises a cylinder which is provided on either of the inner part or the outer part, a head part which has an orifice which divides the space inside this cylinder into two parts, and a shaft part which is provided on the other of the inner part or the outer part and supports the head part having been inserted inside this cylinder. The damping force is generated by fluid resistance of a fluid passing through the orifice by backward movement of the inner part. 
   When the inner part in the forward position is moved backward by the force of the forcing device, accompanying this, the head part inside the cylinder is moved or relatively moved while the fluid is passed through the orifice provided on this head part. Accordingly, the damping can be applied properly to the movement of the inner part. 
   A flow channel of the fluid reaching the orifice is made narrower as the pushing-in speed of the inner part becomes greater. 
   As the speed of movement or relative movement of the head part, that is, the speed of backward movement of the inner part constituting the locking device, that is, the speed of movement of the opening-and-closing moving body toward the stopped position, becomes greater, the damping force on the backward movement can be made greater. The striking part and struck part are mutually striking in a manner such that an impact noise is not made regardless of the speed of the movement toward the stopped position of the opening-and-closing moving body. 
   In the locking device of the invention, the stopped state of an opening-and-closing moving body can be produced properly, and it can be maintained stably, regardless of the speed of the movement of the opening-and-closing moving body toward that stopped position. Also, the stopping can be accomplished gently. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional plan view of essential components of a locking device; 
       FIG. 2  is a sectional side view of the essential components of the same; 
       FIG. 3  is a front view of a catcher body ( 2 ); 
       FIG. 4(   a ) is a sectional side view of the essential components of the locking device,  FIG. 4(   b ) is a sectional plan view of the essential components, and  FIG. 4(   c ) is a front view of the catcher body ( 2 ) (a striker body ( 1 ) is shown in section taken along line  4 ( c )— 4 ( c ) in  FIG. 2 . Same below up to  FIG. 13(   c )) 
       FIG. 5(   a ) is a sectional side view of the essential components of the locking device,  FIG. 5(   b ) is a sectional plan view of the essential components, and  FIG. 5(   c ) is a front view of the catcher body ( 2 ); 
       FIG. 6(   a ) is a sectional side view of the essential components of the locking device,  FIG. 6(   b ) is a sectional plan view of the essential components, and  FIG. 6(   c ) is a front view of the catcher body ( 2 ); 
       FIG. 7(   a ) is a sectional side view of the essential components of the locking device,  FIG. 7(   b ) is a sectional plan view of the essential components, and  FIG. 7(   c ) is a front view of the catcher body ( 2 ); 
       FIG. 8(   a ) is a sectional side view of the essential components of the locking device,  FIG. 8(   b ) is a sectional plan view of the essential components, and  FIG. 8(   c ) is a front view of the catcher body ( 2 ); 
       FIG. 9(   a ) is a sectional side view of the essential components of the locking device,  FIG. 9(   b ) is a sectional plan view of the essential components, and  FIG. 9(   c ) is a front view of the catcher body ( 2 ); 
       FIG. 10(   a ) is a sectional side view of the essential components of the locking device,  FIG. 10(   b ) is a sectional plan view of the essential components, and  FIG. 10(   c ) is a front view of the catcher body ( 2 ); 
       FIG. 11(   a ) is a sectional side view of the essential components of the locking device,  FIG. 11(   b ) is a sectional plan view of the essential components, and  FIG. 11(   c ) is a front view of the catcher body ( 2 ); 
       FIG. 12(   a ) is a sectional side view of the essential components of the locking device,  FIG. 12(   b ) is a sectional plan view of the essential components, and  FIG. 12(   c ) is a front view of the catcher body ( 2 ); and 
       FIG. 13(   a ) is a sectional side view of the essential components of the locking device,  FIG. 13(   b ) is a sectional plan view of the essential components, and  FIG. 13(   c ) is a front view of the catcher body ( 2 ). 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Hereunder, preferred embodiments for implementing the invention will be explained with reference to  FIG. 1  through  FIG. 13(   a )– 13 ( c ). 
     FIG. 1  shows a striker body  1  and a catcher body  2  constituting a locking device in a disassembled state viewed from above, and  FIG. 2  shows the striker body  1  and the catcher body  2  viewed from a side.  FIG. 3  shows the catcher body  2  viewed from a right side in  FIG. 2 . 
     FIG. 4(   a )– 4 ( c ) through  FIG. 13(   a )– 13 ( c ) show each operation of the locking device for each stage so as to make the operation easier to understand. When an opening-and-closing moving body  3  is moved toward a stopped position (moved forward), the striker body  1  and the catcher body  2  are locked in the order of  FIGS. 4(   a )– 4 ( c ),  FIGS. 5(   a )– 5 ( c ) and  FIGS. 6(   a )– 6 ( c ), and the opening-and-closing moving body  3  is positioned at the stopped position (position in  FIGS. 6(   a )– 6 ( c )) by this locking. When the opening-and-closing moving body  3  in the stopped position is moved toward the original position (moved back), the locking between the striker body  1  and the catcher body  2  is released in the order of  FIGS. 7(   a )– 7 ( c ),  FIGS. 8(   a )– 8 ( c ), and  FIGS. 9(   a )– 9 ( c ). In the case that an inner part  20  of the catcher body  2  is moved backward by an erroneous operation while in a state in which the striker body  1  is not inserted into the catcher body  2 , when the opening-and-closing moving body  3  is moved toward the stopped position so as to cause the striker body  1  to be inserted into the catcher body  2 , the striker body  1  and the catcher body  2  are locked in the order of  FIGS. 10(   a )– 10 ( c ),  FIGS. 11(   a )– 11 ( c ),  FIGS. 12(   a )– 12 ( c ), and  FIGS. 13(   a )– 13 ( c ), and the opening-and-closing moving body  3  is positioned at the stopped position by this locking. 
   The locking device pertaining to the embodiment is for locking the opening-and-closing moving body  3  such as a sliding door  30  or drawer in the stopped position so as to stably maintain this stopped state. 
   For example, in the case that it is used in a sliding door  30 , the state in which the sliding door  30  closes an open part is maintained by the locking device. 
   Also, in the case that it is used in a drawer, the state in which the drawer is housed and the open part of the drawer housing body is closed by the front plate part of the drawer is maintained by the locking device. 
   The locking device has the striker body  1  and the catcher body  2 . 
   The striker body  1  is provided on either a striking part  31  of the opening-and-closing moving body  3  (for example, an end part  32  positioned at a front of movement of the sliding door  30  when it is moved to be closed in) which is struck against a struck part  42  of a non-moving body  4  (for example, an inner surface part  41  of an open part of a building, or the like, which is closed to be capable of opening by the sliding door  30 ) in a stopped position, or is provided on the struck part  42  of the non-moving body  2 , and the catcher body  2  is provided on the other of these. 
   (Striker Body  1 ) 
   The striker body  1  has a shaft part  10  which extends following the direction of movement of the opening-and-closing moving body  3 , and a locking projection  11  which projects out sideways from the side of the shaft part  10 . 
   In the illustrated example, the striker body  1  is one surface of a roughly rectangular plate-shaped attachment plate  12 , and it is constituted such that one end of a bar-shaped shaft part  10  is integrally connected in a position at about the middle in a longitudinal direction. The shaft part  10  projects out in a direction orthogonal to one surface of the attachment plate  12 . In such attachment plate  12 , insertion holes  13  for screws, or the like, are formed respectively on both sides surrounding the shaft part  10 . In the illustrated example, the striker body  1  is provided on a sliding door frame  40 , that is, the non-moving body  4 , by fixing the other side of the attachment plate  12  to the sliding door frame  40  which constitutes the inner surface part of the open part which is closed by the sliding door  30  using screws, or the like, inserted into the insertion holes  13 . In the illustrated example, the striker body  1  is attached to the sliding door frame  40  in a manner such that the shaft part  10  projects out toward the lateral direction from the sliding door frame  40  which follows the vertical direction. Also, in the illustrated example, the shaft part  10  of such striker body  1  is constituted roughly as a circle in section in the direction orthogonal to its axial line. Also, in the illustrated example, locking projections  11  are provided respectively in positions on both sides in the diameter direction of the other end part of such shaft part  10 . The locking projections  11  in the two places are constituted so as to have the same dimensions and same shape, and in addition, one projects out upwardly and the other one projects out downwardly. 
   (Catcher Body  2 ) 
   The catcher body  2  has an inner part  20  which has a receiving part  201  for the striker body  1 , an outer part  21  which holds the inner part  20  to be capable of moving forward and backward and to be capable of rotating centered on the longitudinal axis of the inner part  20 , a forcing device  22  which normally forces the inner part  20  in the backward direction of drawing into the outer part  21 , and a damping device  23  which applies damping to the movement in the backward direction (movement toward the left side in  FIGS. 4(   a )– 4 ( c )) of the inner part  20  by the forcing device  22 . 
   In the illustrated example, the inner part  20  is held, and in addition, the forcing device  22  and the damping device  23  are held inside the outer part  21  which has a cylindrical shape in which one cylinder end is open and the other cylinder end is closed. Also, in the illustrated example, the catcher body  2  is provided on the sliding door  30 , that is, the opening-and-closing moving body  3 , by first inserting the other end side of the inner part  20  into the attachment hole  33  which is open in the end part  32  positioned on the front side of movement when the sliding door  30  is moved to be closed and continues inside the sliding door  30  in a direction following the direction of movement of the sliding door  30 . In the illustrated example, the one cylinder end of the inner part  20  thus inserted is positioned about on the same surface as the surface of the end part  32  of the sliding door  30 . 
   (Catcher Body  2 /Inner Part  20 ) 
   In the illustrated example, the inner part  20  has a main body part  202  which has a cylindrical shape in which both cylinder ends are open. The main body part  202  is divided by a dividing wall  202   a  into two parts, being a forward chamber  202   b  which is narrow in depth, and a rear chamber  202   c  which is wide in depth. Also, the forward chamber  202   b  serves as the receiving part  201 . 
   In the receiving part  201  of the inner part  20 , there is formed a catch groove  203  which is formed of an entrance groove part  203   a  which follows the receiving direction of the striker body  1 , and a deep side groove part  203   c  which is connected to the deep end of the entrance groove part  203   a  and extends toward a direction intersecting the receiving direction while making a corner  203   b  in the place of connection. 
   In the illustrated example, a circular flange  202   d  which projects outwardly is formed on the front cylinder end of the main body part  202 . In the circular flange  202   d , introduction cavities  202   f  for the locking projections  11  of the striker body  1 , which are connected to the cylinder front end opening  202   e  and extend to the side, are formed respectively on both sides in the diameter direction of the cylinder front end opening  202   e  of this main body part  202 , and the introduction cavity  202   f  serves as an entrance of the entrance groove part  203   a  of the catch groove  203 . 
   The catch groove  203  is constituted as a notch shape which passes through the side wall of the forward chamber  202   b  of the main body part  202 . Also, the entrance groove part  203   a  continues straight following the cylinder axis of the forward chamber  202   b  up to a position at about the middle in the longitudinal direction of this forward chamber  202   b . An inner corner part  203   d  and an outer corner part  203   e  are formed in the place of connection between the deep side groove part  203   c  and the entrance groove part  203   a . In the illustrated example, the outer corner part  203   e  has a slope about 30 degrees relative to the cylinder axial line of the forward chamber  202   b . The inner corner part  203   d  is roughly parallel to the outer corner part  203   e , and is shorter than the outer corner part  203   e . A part ahead of the inner corner part  203   d  of the deep side groove part  203   c  extends in a direction roughly orthogonal to the cylinder axial line of the forward chamber  202   b . In the deepest part of the deep side groove part  203   c , there is formed a catching surface  203   f  for the locking projection  11  of the striker body  1 , which is oriented toward the rear. 
   In the illustrated example, the catch grooves  203  are formed respectively on one side and the other side of a second imaginary plane y including the central axial line of the inner part  20 , that is, the cylinder axial line of the inner part  20  following the longitudinal direction of the inner part  20 . A pair of catch grooves  203  is formed such that when viewing the inner part  20  in the direction of viewing one catch groove  203  from the front, the other catch groove  203  positioned on the back side is vertically inverted to the catch groove  203  on the one side. 
   On the outside of the rear chamber  202   c  in the inner part  20  in the vicinity of the position of formation of the dividing wall  202   a , there is formed a lock projection  204  which enters a lock groove  213  (described later). In the illustrated example, the lock projections  204  are formed respectively on both sides in the diameter direction of the inner part  20 . A line part joining the positions of formation of the pair of catch grooves  203  has about a 90 degree angle to a line part joining the positions of formation of the pair of lock projections  204 . 
   A circular flange  202   g  which projects outwardly is formed also on the rear cylinder end of the main body part  202  of the inner part  20 . 
   (Catcher Body  2 /Outer Part  21 ) 
   In the illustrated example, the outer part  21  is constituted by combining an inner cylinder body  210  which has an inner diameter about equal to the outer diameter of the inner part  20  and both cylinder ends open, and an outer cylinder body  214  which has an inner diameter about equal to the outer diameter of the inner cylinder body  210  and the cylinder front end (right side in  FIGS. 4(   a )– 4 ( c )) open and the cylinder rear end (left side in  FIGS. 4(   a )– 4 ( c )) closed. The cylinder front end (right side in  FIGS. 4(   a )– 4 ( c )) of the inner cylinder body  210  is connected in a position at about the middle in the length direction of the roughly rectangular plate-shaped attachment plate  211 . The attachment plate  211  is pierced through by the open cylinder front end of the inner cylinder body  210 . In such attachment plate  211 , insertion holes  212  for screws, or the like, are formed respectively on both sides surrounding the position of connection of the inner cylinder body  210 . In the illustrated example, the catcher body  2  is provided on the sliding door  30  by fixing the attachment plate  211  to the surface of the end part  32  of the sliding door  30  using a screw, or the like, inserted into the insertion holes  212 . 
   In the illustrated example, the total length of the inner cylinder body  210  is constituted to become shorter than the total length of the main body part  202  of the inner, part  20  and the outer cylinder body  214 . Furthermore, the total length of the main body part  202  of the inner part  20  is constituted to become shorter than the total length of the outer cylinder body  214 . In the illustrated example, the inner cylinder body  210 , the outer cylinder body  214 , and the main body part  202  of the inner part  20  are assembled together by inserting the inner cylinder body  210  with the cylinder rear end side of the inner cylinder body  210  first into the outer cylinder body  214  from the cylinder front end of the outer cylinder body  214 , up to a position where the cylinder front end of the outer cylinder body  214  is butted against the back surface of the attachment plate of the inner cylinder body  210 , and in addition, by winding a compression coil spring  220  on the outside of the main body part  202  of the inner part  20  in a manner such that the front end of the spring is pushed against the cylinder rear end of the inner cylinder body  210  thus inserted, and the rear end of the spring is pushed against the circular flange  202   g  formed on the cylinder rear end of the main body part  202  of the inner part  20 . In the illustrated example, the spring  220  functions as the forcing device  22 . 
   In this embodiment, in the outer part  21 , there is formed a lock groove  213  which is formed of a straight groove part  213   a  which follows the direction of movement of the inner part  20 , and a front side groove part  213   c  which is connected to the front end of the straight groove part  213   a  and extends toward a direction intersecting the direction of movement while making a corner  213   b  in the place of connection. In addition, a lock projection  204  which enters the lock groove  213  is formed on the inner part  20 . 
   In the illustrated example, the straight groove part  213   a  of the lock groove  213  is formed so as to extend following the cylinder axis of the outer part  21 . The front side groove part  213   c  extends in a direction roughly orthogonal to the cylinder axis of this outer part  21 . In the illustrated example, an outer corner part  213   d  of the corner formed in the place of connection between such straight groove part  213   a  and front side groove part  213   c  is formed in an R-shape. A catching surface  213   e  of the lock projection  204 , which is provided on the front side, is formed by this front side groove part  213   c . In the illustrated example, the lock groove  213  has a rear side groove part  213   f  which is connected to the rear end of the straight groove part  213   a  and extends in a direction roughly orthogonal to the cylinder axis of the outer part  21 . The rear side groove part  213   f  extends in the same direction as the front side groove part  213   c , so that the lock groove  213  presents a roughly square bracket shape viewed from the side. 
   In the illustrated example, the lock grooves  213  are formed respectively on one side and the other side of an imaginary plane surrounding the longitudinal axis of the inner part  20 , that is, a first imaginary plane x surrounding the cylinder axial line of the outer part  21 . A pair of lock grooves  213  is formed such that when viewing the inner part  20  in the direction of viewing one lock groove  213  from the front, the other lock groove  213  positioned on the back side is vertically inverted to the lock groove  213  on the one side. 
   In this embodiment, in the forward position of the inner part  20 , the lock projection  204  is caught on the catching surface  213   e  of the front side groove part  213   c  of the lock groove  213  by the forcing of the forcing device  22 , whereby the forward state is maintained. 
   The locking projection  11  of the striker body  1  which enters the receiving part  201  of the inner part  20  in the forward position accompanying the movement of the opening-and-closing moving body  3  toward the stopped position is pushed against the outer corner part  203   e  of the corner of the catch groove  203  and the inner part  20  is rotated forward. The locking projection  11  is caught on the catching surface  203   f  of the deep side groove part  203   c  of the catch groove  203  by the forward rotation. The lock projection  204  which is in the front side groove part  213   c  of the lock groove  213  part enters the straight groove part  213   a.    
   (Function) 
   When the opening-and-closing moving body  3  is moved toward the stopped position, the striker body  1  enters the receiving part  201  of the inner part  20  of the catcher body  2 , and the locking projection  11  of the striker body  1  enters the catch groove  203  ( FIGS. 4(   a )– 4 ( c )). The locking projection  11  of the striker body  1  in the catch groove  203  is pushed against the outer corner part  203   e  of the corner of this catch groove  203 , and by this, the inner part  20  in the forward position is rotated forward ( FIGS. 4(   a )– 4 ( c ) to  FIGS. 5(   a )– 5 ( c )). By this forward rotation, the locking projection  11  of the striker body  1  enters the deep side groove part  203   c  of the catch groove  203 , and by this, the striker body  1  is coupled with the inner part  20  ( FIGS. 5(   a )– 5 ( c )). In addition, by this forward rotation, the lock projection  204  of the inner part  20  is removed from the front side groove part  213   c  of the lock groove  213  part and enters the straight groove part  213   a . Because the inner part  20  in the forward position is normally forced in the backward direction by the forcing of the forcing device  22 , the inner part  20  is moved backward by the entering of the lock projection  204  inside the straight groove part  213   a . By the backward movement of the inner part  20 , the striker body  1  also is drawn into the depth of the catcher body  2  ( FIGS. 6(   a )– 6 ( c )). Accordingly, a state in which the striking part  31  of the opening-and-closing moving body  3  and the struck part  42  of the non-moving body  4  are mutually striking is produced compulsorily, and the state can be maintained stably. Even if the speed of movement toward the stopped position of the opening-and-closing moving body  3  is comparatively small, the opening-and-closing moving body  3  can be moved assuredly up to the expected stopped position of the opening-and-closing moving body  3 , in which the striking part  31  and struck part  42  are mutually striking by the coupling between the striker body  1  and the inner part  20 . 
   For example, in the case that the locking device is used in the sliding door  30 , a state in which the sliding door  30  closes the open part without a gap can be produced assuredly accompanying the closing operation of the sliding door  30 , and the state can be maintained stably. 
   Because the locking device has the damping device  23  which applies damping to the backward movement of the inner part  20  by the forcing device  22 , even if the speed of movement toward the stopped position of the opening-and-closing moving body  3  is comparatively large, this can be attenuated, and the striking part  31  and struck part  42  strike firmly and without an impact noise. 
   (Damping Device  23 ) 
   In the illustrated example, such damping device  23  comprises:
     (1) a cylinder  230  which is provided on the inner part  20 ,   (2) a head part  231  which has an orifice  231   a  which divides the space inside the cylinder  230  into two parts, and   (3) a shaft part  232  which is provided on the outer part  21  and supports the head part  231  inserted into the cylinder  30 ; and   (4) the damping force is generated by fluid resistance of a fluid passing through the orifice  231   a  by backward movement of the inner part  20 .   

   Concretely, in the illustrated example, the cylinder  230  is built into the rear chamber  202   c  of the main body part  202  of the inner part  20 . The rear end of the shaft part  232  is built into the rear end of the outer cylinder body  214  of the outer part  21 . A first compression coil spring  233  is interposed between the front end of the shaft part  232  and the front end of the cylinder  230 , and when not operating, the head part  231  is positioned to the rear end side of the cylinder  230 . The inside of the cylinder  230  typically is filled with a viscous fluid such as silicon oil as said fluid ( FIG. 1 ). 
   When the inner part  20  in the forward position is moved backward by the forcing of the forcing device  22 , accompanying this, the cylinder  230  is moved backward while the fluid is passed through the orifice  231   a  provided on the head part  231 . By this, the damping can be applied properly to the movement of this inner part  20 . 
   In this embodiment, the flow channel  236  of the fluid reaching the orifice  231   a  is made narrower as the pushing-in speed of the inner part  20  becomes greater. 
   Concretely, in the illustrated example, the head part  231  is combined on the shaft part  232  to be capable of moving forward and backward following the axial direction of the shaft part  232 , and in addition, a cylindrical part  231   b  is formed to the rear of the head part  231 . The head part  231  is normally forced forward by a second compression coil spring  235  which is interposed between a flow channel formation  234  provided on the shaft part  232  and the back surface of this head part  231  so as to be positioned inside the cylindrical part  231   b  of the head part  231 . The fluid passes through the flow channel  236  between the outer surface of the flow channel formation  234  and the inner surface of the cylindrical part  231   b . The flow channel formation  234  is constituted such that the outer diameter is made larger gradually as it goes backward. As the speed of movement of the cylinder  230 , that is, the speed of backward movement of the inner part  20  constituting the locking device, that is, the speed of movement of closing of the opening-and-closing moving body  3 , becomes greater, the head part  231  is moved backward in opposition to the forcing of the second compression coil spring  235  by the resistance of the fluid accompanying the movement of the cylinder  230 , and the flow channel  236  is made narrower. 
   By this, in this embodiment, as the speed of backward movement of the inner part  20  constituting the locking device, that is, the speed of closing of the opening-and-closing moving body  3 , becomes greater, the damping force on the backward movement can be made greater. The striking part  31  and struck part  42  are mutually striking in a manner such that an impact noise is not made regardless of the magnitude of the speed of movement toward the stopped position of the opening-and-closing moving body  3 . As the damping device  23 , more concretely, that which is described in Japanese Patent Application (Kokai) No. 2003-433572, which was previously disclosed by the present applicants, can be used. 
   (Other Structure) 
   In this embodiment, by moving the opening-and-closing moving body  3  from the stopped position of this opening-and-closing moving body  3 , in which the locking projection  11  of the striker body  1  is caught in the deep side groove part  203   c  of the catch groove  203  of the inner part  20  in the backward position, toward the original position, that is, by moving the sliding door  30  in the opening direction in the illustrated example, the lock projection  204  is pushed against the outer corner part  213   d  of the corner of the lock groove  213  and the inner part  20  is rotated in reverse accompanying the moving of the inner part  20  toward the forward position. By this reverse rotation, the locking projection  11  is removed from the deep side groove part  203   c  of the catch groove  203 . 
   In the illustrated example, when the inner part  20  is moved forward accompanying the movement of the opening-and-closing moving body  3  toward the original position from the stopped position ( FIGS. 7(   a )– 7 ( c )), the lock projection  204  of the inner part  20  is moved from the rear end of the lock groove  213  to the front end, and in addition, it is pushed from the rear against the outer corner part  213   d  of the corner of the R-shaped lock groove  213  as previously noted, and by this pushing, the inner part  20  is rotated in reverse ( FIGS. 8(   a )– 8 ( c )). 
   By this, in this embodiment, by moving the opening-and-closing moving body  3  in the stopped position in the opening direction, the lock projection  204  of the inner part  20  again enters the front side groove part  213   c  of the lock groove  213  whereby the inner part  20  is restored to the forward position, and this state can be maintained. In addition, the coupling between the inner part  20  and striker is released whereby the striker body  1  can be removed from the receiving part  201  of the inner part  20 . The state of maintaining the stopped position of the opening-and-closing moving body  3  by the locking device can be released smoothly with one action ( FIGS. 9(   a )– 9 ( c )). 
   In this embodiment, on the side of the entrance of the entrance groove part  203   a  of the catch groove  203  on the receiving part  201  of the inner part  20 , there is formed a cam surface  203   g  which is struck by the locking projection  11  by striking the striker body  1  on the inner part  20  rotated forward and moved to the backward position by an erroneous operation, and causes the inner part  20  to rotate in reverse so that the locking projection  11  enters the catch groove  203 . 
   In the illustrated example, on each side of a pair of introduction cavities  202   f  formed in the cylinder front end of the main body part  202  of the inner part  20  for the locking projection  11  of the striker body  1 , there is formed a cam surface  203   g  which has a slope that gradually retreats as it approaches the introduction cavity  202   f . In the case that the inner part  20  rotates forward erroneously in a state in which the striker body  1  is not inserted inside the receiving part  201  of the inner part  20 , that is, when the opening-and-closing moving body  3  is not moved to the stopped position, the locking projection  11  can strike the cam surface  203   g  of the inner part  20  moved backward by the forcing of the forcing device  22  by moving the opening-and-closing moving body  3  toward the stopped position. 
   If the opening-and-closing moving body  3  is moved toward the stopped position from a state in which the inner part  20  is erroneously moved backward, the locking projection  11  of the striker body  1  is struck on the cam surface  203   g , and the inner part  20  is rotated in reverse ( FIGS. 10(   a )– 10 ( c )). By this, it becomes possible to make the locking projection  11  of the striker body  1  enter into the catch groove  203  ( FIGS. 11(   a )– 11 ( c )). At this time, the lock projection  204 . of  the inner part  20  is positioned at the rear end of the lock groove  213 . Because the rear side groove part  213   f  is formed at the rear end of the lock groove  213 , this reverse rotation is not obstructed ( FIGS. 11(   a )– 11 ( c )). When the locking projection  11  of the striker body  1  enters the catch groove  203 , the locking projection  11  is pushed against the outer corner part  203   e  of the corner of the catch groove  203 , the inner part  20  is rotated forward, the locking projection  11  is caught in the deep side groove part  203   c  of the catch groove  203 , and a state being the same as when the striker body  1  is received by the catcher body  2  is produced correctly ( FIGS. 12(   a )– 12 ( c ) to  FIGS. 13(   a )– 13 ( c )). 
   In this embodiment, the locking projections  11  are formed respectively on both the left and right sides of the striker body  1 . In addition, the catch grooves  203 , lock grooves  213 , and lock projections  204  are formed respectively on one side and the other side of an imaginary plane including the central axial line of the inner part  20  following the longitudinal direction of this inner part  20 . 
   In the illustrated example, the lock grooves  213  and lock projections  204  are formed on both sides of the first imaginary plane x including the central axial line of the inner part  20 . The catch grooves  203  are formed on both sides of the second imaginary plane y orthogonal to this first imaginary plane x and including the central axial line of the inner part  20 . 
   As a result, in this embodiment, the inner part  20  can be rotated forward smoothly accompanying the movement toward the stopped position of the opening-and-closing moving body  3 . By moving the opening-and-closing moving body  3  toward the opening direction from the stopped position of the opening-and-closing moving body  3  having the striker body  1  coupled with the inner part  20  by this forward rotation, a state in which the inner part  20  is restored to the forward position while smoothly rotating the inner part  20  in reverse to release such coupling can be maintained. 
   The disclosure of Japanese Patent Application No. 2004-193351, filed on Jun. 30, 2004, is incorporated in the application. 
   While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.