Patent Publication Number: US-2022219745-A1

Title: Carrier device with coupling mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2021-004118, filed Jan. 14, 2021, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a carrier device comprising a coupling mechanism for coupling, for example, a caster-mounted carriage to an automatic controlled vehicle. 
     2. DESCRIPTION OF THE RELATED ART 
     In production sites such as factories, warehouses and the like, caster-mounted carriages are used to move objects to be carried. The caster-mounted carriages may be carts or wagons. To move the carriages to desired locations, an automatic controlled vehicle may be used. In this case, each carriage is coupled to the automatic controlled vehicle via a coupling mechanism. The coupling mechanism couples the carriage and the automatic controlled vehicle to each other as needed. The coupling mechanism can also decouple the carriage from the automatic controlled vehicle. 
     JP 2013-232078 A (Patent Literature 1) describes an automatic controlled vehicle including a coupling mechanism that uses a coupling pin. The automatic controlled vehicle is configured to be able to enter the undersides of carriages. The coupling mechanism includes a coupling pin, a drive mechanism for moving the coupling pin in the vertical direction, and a pin receiving portion. The coupling pin is provided on an upper surface of the automatic controlled vehicle. The pin receiving portion is provided on the lower surface of the carriage. The coupling pin is ascended by the drive mechanism, and then, the coupling pin is inserted to the pin receiving portion. Thus, the carriage is coupled to the automatic controlled vehicle. 
     JP 2019-162953 A (Patent Literature 2) describes an automatic controlled vehicle including a coupling portion. The coupling portion includes a coupling rod and a clamping mechanism. The coupling rod is provided on the lower surface of the carriage. The clamping mechanism is provided on the upper surface of the automatic controlled vehicle. While the automatic controlled vehicle is inserted underneath the carriage, the coupling rod is grasped with the clamping mechanism. Thus, the carriage is coupled to the automatic controlled vehicle. 
     JP 201.8-24415 A (Patent Literature 3) describes an automatic controlled vehicle comprising a guide portion and a coupling mechanism. The first example of the coupling mechanism described in Patent Literature 3 includes a pair of guide portions, a coupled member and a coupling pin. The pair of guide portions are provided on the upper surface of the automatic controlled vehicle. The coupled member is provided on the lower surface of the carriage. The coupling pin is movable along the horizontal direction. The coupled member includes a pin receiving hole formed therein to insert the coupling pin thereto. While the coupled member is inserted between the guide portions, the coupling pin is inserted to the pin receiving hole. Thus, the carriage is coupled to the automatic controlled vehicle. 
     The second example of the coupling mechanism in Patent Literature 3 comprises a pair of guide portions, a pair of coupling shafts and a coupling member. The pair of guide portions are provided on the upper surface of the automatic controlled vehicle. The pair of coupling shafts are provided on the lower surface of the carriage. The coupling member is movable along the horizontal direction. While the coupling shafts are inserted between the guide portions, the coupling member is pressed against the coupling shafts. Thus, the carriage is coupled to the automatic controlled vehicle. 
     In the coupling mechanism described in Patent Literature 1, the coupling pin is inserted to the pin receiving portion. With this structure, if the relative positions of the automatic controlled vehicle and the carriage are shifted even slightly during coupling, the coupling pin cannot be inserted to the pin receiving portion. 
     The clamping mechanism described in the above-mentioned patent document 2 can be used even if the positioning accuracy of the automatic controlled vehicle relative to the carriage may be loose. However, when the automatic controlled vehicle and the carriage turned around the vertical axis, excessive load is applied to the clamping mechanism, which undesirably may easily cause damage to the clamping mechanism. 
     In the first example of Patent Literature 3, the horizontally movable metal-made coupling pin is inserted to the pin receiving hole of the metal-made coupled member. With such a structure, contact noise between the coupling pin and the pin receiving hole and vibration thereof are problematic. Especially in clean rooms where a clean environment is required, the generation of fine particles (micro-particles) by friction between metals creates a major problem. In the second example of Patent Literature 3, the coupling member is pressed against the coupling shaft. In such a structure, it is necessary to keep pressing the coupling member against the coupling rod with a large force. Therefore, a great amount of consumption energy is involved, placing a heavy load on the battery. Further, the rigidities of the coupling member and the coupling shaft need to be considerably increased. 
     The present invention provides a carrier device comprising a coupling mechanism that has a large coupling strength between the automatic controlled vehicle and the carriage and also can suppress generation of dust such as metal particles. 
     BRIEF SUMMARY OF THE INVENTION 
     According to one embodiment, a carrier device comprises a coupling mechanism that couples an automatic controlled vehicle to a carriage. The coupling mechanism comprises a first shaft member, a second shaft member and a third shaft member. The first shaft member and the second shaft member are disposed on the carriage with an interval therebetween in a horizontal direction. The first shaft member and the second shaft member each extend downward from the carriage. The third shaft member is disposed between the first shaft member and the second shaft member. The third shaft member extends downward from the carriage. 
     The automatic controlled vehicle comprises a guide rail section, a lock member and an actuator. The guide rail section includes a pair of rail members extending in the horizontal direction. The guide rail section comprises a gap formed between the pair of rail members. In to the gap, the first shaft member and the second shaft member can enter. The lock member is movable between a first position and a second position. The lock member is separated from the third shaft member when moved to the first position. The lock member is fitted with the third shaft member when moved to the second position. The actuator moves the lock member between the first position and the second position. 
     According to a carrier device comprising a coupling mechanism according to this embodiment, a large coupling strength can be obtained between the automatic controlled vehicle and the carriage, and further the generation of dust can be suppressed. 
     In the above-provided embodiment, the first shaft member may include a first roller portion, the second shaft member may include a second roller portion, and the third shaft member may include a third roller portion. The first roller portion rotates around a first axis extending along vertical direction. The second roller portion rotates around a second axis extending along the vertical direction. The third roller portion rotates around a third axis extending along the vertical direction. 
     The first roller portion, the second roller portion and the third roller portion are made of a material having rubber elasticity. The diameter of the first roller portion and the diameter of the second roller portion are equivalent to each other. The diameter of the third roller portion may be less than the diameter of the first roller portion and the diameter of the second roller portion. 
     The guide rail section comprises straight portions, a first expanding portion and a second expanding portion. The straight portions form longitudinal parts of the pair of rail members and are parallel to each other. In the first expanding portion, the gap expands as a distance from one end of the straight portions increases. In the second expanding portion, the gap expands as a distance from the other end of the straight portion increases. 
     The lock member may include one side surface and the other side surface along a direction of movement of the lock member. The lock member may include an end portion including a pair of guide surfaces. The distance between the guide surfaces decreases from the respective side surfaces toward the end surface of the lock member. Further, the lock member may include a fitting portion. The fitting portion comprises a recess portion to fit with the third roller portion. 
     Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
         FIG. 1  is a perspective view of a carrier device according to one embodiment. 
         FIG. 2  is a perspective view of the carrier device shown in  FIG. 1  while an automatic controlled vehicle thereof and a carriage are separated from each other. 
         FIG. 3  is a front view partially showing the carrier device. 
         FIG. 4  is a side view partially showing the carrier device. 
         FIG. 5  is a plan view of the automatic controlled vehicle of the carrier device. 
         FIG. 6  is a plan view showing the automatic controlled vehicle of the carrier device and a part of the carriage. 
         FIG. 7  is a plan view showing a state where the carriage is coupled by the lock member to the carrier device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A carrier device according to one embodiment will be described with reference to  FIGS. 1 to 7 . 
       FIG. 1  is a perspective diagram showing a carrier device  10 . The carrier device  10  includes an automatic controlled vehicle  11 , a carriage  12  and a coupling mechanism  13 . The coupling mechanism  13  has the function of coupling the automatic controlled vehicle  11  and the carriage  12  to each other.  FIG. 2  shows the state where the automatic controlled vehicle  11  is separated from the carriage  12 .  FIG. 3  shows a front view of a part of the carrier device  10 , and  FIG. 4  shows a side view of a part of the carrier device  10 . 
     The automatic controlled vehicle  11  will be explained in detail later, and the carriage  12  will be explained first. 
     The carriage  12  comprises a frame structure  20 , casters  21 ,  22 ,  23  and  24 , a first shaft member  31 , a second shaft member  32  and a third shaft member  33 . The shaft members  31 ,  32  and  33  are provided in the frame structure  20 . The shaft members  31 ,  32  and  33  forms a part of the coupling mechanism  13 . In an upper portion of the frame structure  20 , a loading section  35  (shown in  FIGS. 1 and 2 ) is formed for loading an object to be carried thereon. 
     The frame structure  20  includes a pair of lower frames  36  and  37 , a vertical frame  38 , upper frames  40 ,  41  and  42 , a reinforcing member  43  and the like. The vertical frame  38  extends along the vertical direction. Under the upper frames  40 ,  41  and  42 , a space section  45  is formed. To the space section  45 , the automatic controlled vehicle  11  can enter from the horizontal direction. 
     The casters  21  and  22  are provided on respective ends of the lower frame  36 . The casters  23  and  24  are also provided on respective ends of the other lower frame  37 . The casters  21 ,  22 ,  23  and  24  can each rotate around a vertical axis. The casters  21 ,  22 ,  23  and  24  can change their orientations according to the direction of movement of the carriage  12 . 
     The first shaft member  31  is provided at a position of the upper frame  41 , which is closer to one longitudinal end  41   a  thereof. The first shaft member  31  is disposed on the lower surface of the upper frame  41 . The first shaft member  31  extends downward from the upper frame  41 . The first shaft member  31  includes a first roller portion  51  which is freely rotatable. The first roller portion  51  is made, for example, from a material having rubber elasticity, such as a urethane elastomer. The first roller portion  51  can swivel around a first axial line X 1  (shown in  FIG. 4 ) extending along the vertical direction. 
     The second shaft member  32  is provided at a position of the upper frame  41 , which is closer to a longitudinal other end  41   b  thereof. The second shaft member  32  is disposed on the lower surface of the upper frame  41 . The second shaft member  32  extends downwards from the upper frame  41 . The second shaft member  32  includes a second roller portion  52  which is freely rotatable. 
     As in the case of the first roller portion  51 , the second roller portion  52  is made, for example, from a rubber elastic material such as a urethane elastomer. The second roller portion  52  can swivel around a second axial line X 2  (shown in  FIG. 4 ) extending along the vertical direction. A diameter D 2  of the second roller portion  52  (shown in  FIG. 6 ) is the same as a diameter D 1  of the first roller portion  51 . 
     The third shaft member  33  is provided between the first shaft member  31  and the second shaft member  32 . The third shaft member  33  is located approximately at the longitudinal center of the upper frame  41 . The third shaft member  33  is disposed on the lower surface of the upper frame  41 . The third shaft member  33  extends downwards from the upper frame  41 . The third shaft member  33  includes a third roller portion  53  which is freely rotatable. 
     The third roller portion  53  is made from a material having rubber elasticity, as in the case of the first roller portion  51  and the second roller portion  52 . The third roller portion  53  can swivel around a third axial line X 3  (shown in  FIG. 4 ) extending along the vertical direction. A diameter D 3  (shown in  FIG. 6 ) of the third roller portion  53  is less than the respective diameters D 1  and D 2  of the first and second roller portions  51  and  52 . 
     As shown in  FIG. 7 , the first shaft member  31 , the second shaft member  32  and the third shaft member  33  are arranged along a virtual straight line M 1  when viewed from above. The virtual straight line M 1  extends along the horizontal direction. As shown in  FIG. 2 , the first shaft member  31  and the second shaft member  32  are disposed on the upper frame  41  with a predetermined distance S 1  therebetween with respect to each other along the horizontal direction. 
     A distance S 2  from the first shaft member  31  to the third shaft member  33  is equivalent to a distance S 3  from the second shaft member  32  to the third shaft member  33 . That is, the first shaft member  31  and the second shaft member  32  are arranged in symmetrical positions with respect to the third shaft member  33  interposed therebetween. 
     Next, the automatic controlled vehicle  11  will be described. 
       FIG. 5  is a plan view showing the automatic controlled vehicle  11 . The automatic controlled vehicle  11  includes a vehicle main body  61  and a coupling unit  62 . The vehicle main body  61  includes a traveling mechanism  60  (shown in  FIG. 2 ). The traveling mechanism  60  is covered by a cover member  63 . The coupling unit  62  is disposed on top of the vehicle main body  61 . The vehicle main body  61  contains software and electrical components for controlling automatic operation. The vehicle main body  61  runs along a predetermined travel path. 
     The traveling mechanism  60  comprises wheels. The vehicle main body  61  moves in a first direction (indicated by arrow F 1 ) and a second direction (indicated by arrow F 2 ) by the traveling mechanism  60 . The traveling mechanism  60  also comprises a steering mechanism. The vehicle main body  61  can be swiveled around the vertical axis Z 1  by the steering mechanism. That is, the vehicle main body  61  can swivel in the first rotational direction indicated by the arrow R 1  and in the second rotational direction indicated by the arrow R 2  in  FIG. 2 . 
     The coupling unit  62  is provided on top of the vehicle main body  61 . The coupling unit  62  forms a part of the coupling mechanism  13 . The coupling unit  62  includes a base plate  70 , a guide rail section  73  including a pair of rail members  71  and  72 , a lock member  74 , an actuator  75  (shown in  FIGS. 3 and 4 ), a detecting section  77  including a plurality of sensors  76 , a display section  78  and the like. The base plate  70  expands in substantially horizontal direction. The pair of rail members  71  and  72  are disposed on top of the base plate  70 . The lock member  74  is moved along the horizontal direction by the actuator  75 . The detecting section  77  has the function of detecting the roller portions  51  and  52 . The base plate  70  is fixed to the upper surface of the vehicle main body  61  by a plurality of fixing members  79  such as bolts. 
     The pair of rail members  71  and  72  are each made of, for example, a metal plate. The rail members  71  and  72  are fixed to the base plate  70  by fixing members  80  (shown in  FIGS. 5 to 7 ). The rail members  71  and  72  includes straight portions  71   a  and  72   a , respectively. The straight portions  71   a  and  72   a  are parallel to each other and extend along the horizontal direction. The straight portions  71   a  and  72   a  form longitudinal parts of the rail members  71  and  72 , respectively. 
     Between the straight portions  71   a  and  72   a , a gap G 1  (shown in  FIG. 6 ) is formed. The gap G 1  is slightly greater than the diameter D 1  of the first roller  51 . The gap G 1  is slightly greater than the diameter D 2  of the second roller portion  52 . For example, the gap G 1  is 1 nm to several mm greater than the diameter D 1  of the first roller  51 . The gap G 1  is 1 mm to several mm greater than the diameter D 2  of the second roller portion  56 . With this structure, the first roller portion  51  and the second roller portion  52  can enter the gap G 1 . 
     At one end side of the guide rail section  73 , a first expanding portion  73   a  is formed. At the other end side of the guide rail section  73 , a second expanding portion  73   b  is formed.  FIG. 6  is a plan view of the automatic controlled vehicle  11  viewed from above. As viewed from above, the guide rail section  73  incudes the first expanding portion  73   a  and the second expanding portion  73   b . In the first expanding portion  73   a , as the distance from one end of the straight portion  71   a  or  72   a  increases, the distance (gap G 1 ) between the rail members  71  and  72  increases. An inlet width W 1  of the first expanding portion  73   a  is twice or more the diameter D 1  of the first roller portion  51 . The inlet width W 1  is also twice or more the diameter D 2  of the second roller portion  52 . With this structure, the first roller portion  51  and the second roller portion  52  can each easily enter between the rail members  71  and  72 . 
     In the second expanding portion  73   b , as the distance from the other end of the straight portion  71   a  or  72   a  increases, the distance (gap G 1 ) between the rail members  71  and  72  increases. An inlet width W 2  of the second expanding portion  73   b  is twice or more the diameter D 1  of the first roller portion  51 . The inlet width W 2  is also twice or more the diameter D 2  of the second roller portion  52 . With this structure, the first roller portion  51  and the second roller portion  52  can each easily enter between the rail members  71  and  72 . 
     The detecting section  77  including a plurality of sensors  76  detects the roller portions  51  and  52  when the automatic controlled vehicle  11  enters the space section  45  of the carriage  12 . In the rail members  71  and  72 , openings  81  (shown in  FIG. 4 ) are formed at positions corresponding to the sensors  76 . Light for sensing is detected by the detecting section  77  through the openings  81 . 
     As shown in  FIGS. 5 to 7 , a groove  85  is formed in the base plate  70 . The groove  85  extends in a direction perpendicular to the straight portions  71   a  and  72   a  of the rail members  71  and  72 . The lock member  74  can move horizontally along the groove  85 . The lock member  74  moves over between a first position (a standby position) shown in  FIGS. 5 and 6  and a second position (a locked position) shown in  FIG. 7 . The actuator  75  (shown in  FIGS. 3 and 4 ) is provided on the base plate  70 . The actuator  75  moves the lock member  74  to the first position and the second position. For example, the actuator  75  is a ball screw mechanism with a servo motor as the driving source. 
     As viewing the automatic controlled vehicle  11  from above, the lock member  74  includes one side surface  90 , the other side surface  91 , an end portion  95  and a fitting portion  100 . The one side surface  90  and the other side surface  91  each extend along a direction parallel to the groove  85 . The end portion  95  includes an end surface  92  and guide surfaces  93  and  94 . The fitting portion  100  includes an opening  96  and a recess portion  97 . The side surfaces  90  and  91  each extend along the direction of movement of the lock member  74 . The lock member  74  moves between the first position and the second position. The end surface  92  is formed in a front side with respect to the direction of movement of the lock member  74  from the first position to the second position. 
     In  FIG. 7 , a distance L 1  is measured between one side surface  90  of the lock member  74  and the other side surface  91 , a distance L 2  is measured between the first roller portion  51  and the second roller portion  52 . The end surface  92  has a width L 3 . Here, L 1  is slightly less than L 2 . For example, L 1  is a few millimeters less than L 2 , and L 3  is sufficiently less than L 2 . That is, the relationship can be expressed as: L 2 &gt;L 1 &gt;L 3 . Between the side surface  90  and the end surface  92 , a first guide surface  93  is formed to diagonally extend. Between the other side surface  91  and the end surface  92 , a second guide surface  94  is formed to diagonally extend. 
     The guide surfaces  93  and  94  are formed on the end portion  95  of the lock member  74 , and therefore the width of the end portion  95  decreases in a tapered form from the side surfaces  90  and  91  towards the end surface  92 . Since the guide surfaces  93  and  94  are formed on the end portion  95 , the lock member  74  can enter between the first shaft member  31  and the second shaft member  32  even if the relative positions of the automatic controlled vehicle  11  and the carriage  12  are slightly displaced with respect to each other. 
     The fitting portion  100  is formed in the end portion  95  of the lock member  74 . The fitting portion  100  comprises the opening  96  and the recess portion  97 . The opening  96  has such a size as to allow the third roller portion  53  to easily enter. The recess portion  97  has such a size for the third roller portion  53  to fit thereinto. The opening  96  and the recess portion  97  are formed in the center of the end surface  92  along the width direction. As shown in  FIG. 6 , the recess portion  97  has the width L 4 . The third roller portion  53  has a diameter D 3 . The width L 4  is slightly greater than the diameter D 3 . 
     The opening  96  is open to the end surface  92  of the lock member  74 . The width L 5  of the opening  96  (shown in  FIG. 6 ) is sufficiently larger than the diameter D 3  of the third roller portion  53 . As shown in  FIG. 6 , the lock member  74  is away from the third shaft member  33  when the lock member  74  is moved to the first position. 
       FIG. 7  illustrates the state where the lock member  74  has been moved from the first position to the second position. When the lock member  74  is moved from the first position to the second position, the third roller portion  53  enters the opening  96 , which is wide and then fits into the recess portion  97 . At this time, the lock member  74  is positioned between the first roller portion  51  and the second roller portion  52 . 
     Now, the operation of the carrier device  10  of this embodiment will be described. 
     First, towards the carriage  12 , which is stopped, the automatic controlled vehicle  11  moves in a direction approaching the carriage  12 . Then, the automatic controlled vehicle  11  enters the space section  45  inside the carriage  12 . When the automatic controlled vehicle  11  enters the inside of the carriage  12 , the vehicle  11  moves forward toward the gap G 1  in the guide rail section  73 . According to the moving direction of the automatic controlled vehicle  11 , the first roller portion  51  or the second roller portion  52  is guided by the first expanding portion  73   a  or the second expanding portion  73   b . Then, the roller portions  51  and  52  enter the gap G 1  of the guide rail section  73 . 
     The gap G 1  of the guide rail section  73  is greater than the diameter D 1  of the first roller portion  51  and the diameter D 2  of the second roller portion  52 . With this structure, when the first roller portion  51  and the second roller portion  52  enter the gap G 1 , the first roller portion  51  and the second roller portion  52  are rotated while touching one of the rail members  71  and  72 , respectively. Thus, the roller portions  51  and  52  are rotated, it is possible to avoid generation of dust, which may be caused by the first roller portion  51  and the second roller portion  52  rubbing against the guide rail section  73 . 
       FIG. 6  illustrates the state where the automatic controlled vehicle  11  has been moved to a predetermined position (the coupling position) with respect to the roller portions  51  and  52  of the carriage  12 . At this time, the lock member  74  is located at the first position (the standby position). When the automatic controlled vehicle  11  is moved to a predetermined position with respect to the carriage  12 , the roller portions  51  and  52  are detected by the sensors  76 , and the automatic controlled vehicle  11  is stopped. At this time, the roller portions  51  and  52  are located in the gap G 1  of the guide rail section  73 . 
       FIG. 7  illustrates the state where the lock member  74  has been moved to the second position (the lock position). The lock member  74  is moved from the first position to the second position by the actuator  75  (shown in  FIGS. 3 and 4 ). When the lock member  74  is moved to the second position, the relative positions of the automatic controlled vehicle  11  and the carriage  12  may be displaced with respect to each other along the length direction of the guide rail section  73 . In that case, the first roller portion  51  or the second roller portion  52  is brought into contact with the first guide surface  93  or the second guide surface  94 . 
     While the first roller portion  51  or the second roller portion  52  in contact with the first guide surface  93  or the second guide surface  94 , the lock member  74  moves toward the second position. Accordingly, the first roller portion  51  or the second roller portion  52  is rotated. In this manner, it is possible to avoid generation of particles (dust), which may occur when the lock member  74  moves to the second position. 
     When the lock member  74  reaches the second position as shown in  FIG. 7 , the third roller portion  53  passes through the opening  96  of the fitting portion  100  and enters the recess portion  97 . Here, the width L 4  of the recess portion  97  (shown in  FIG. 6 ) is slightly greater than the diameter D 3  of the third roller portion  53 . When the third roller portion  53  is brought into contact with the inner surface of the recess  97 , the third roller portion  53  is rotated. In this manner, it is possible to avoid dust generation when the third roller portion  53  enters the recess  97 , which may occur between these members rubbing against each other. 
     In a state where the third roller portion  53  enters the recess  97  of the fitting portion  100 , the automatic controlled vehicle  11  runs. For example, the automatic controlled vehicle  11  moves in the first direction F 1  (shown in  FIG. 1 ) or the second direction F 2 . Here, the third roller portion  53  is fit with the recess portion  97 , and therefore to the automatic controlled vehicle  11  and the carriage  12  can be securely coupled to each other against the load applied to the coupling mechanism  13  when running. 
     The first roller portion  51  and the second roller portion  52  are located in the gap G 1  of the guide rail section  73 . Therefore, the guide rail section  73  inhibits the automatic controlled vehicle  11  and the carriage  12  from moving in the width direction with relative to each other. When the automatic controlled vehicle  11  and the carriage  12  swivel around the vertical axis Z 1 , a load (torque) in the rotational direction is applied to the coupling mechanism  13 . Against such a load in the rotational direction, the coupling mechanism  13  can exhibit a great deal of strength. 
     While the automatic controlled vehicle  11  and the carriage  12  are coupled to each other, the automatic controlled vehicle  11  automatically runs along a predetermined route. As a result, the object to be carried on the carriage  12  are carried to the predetermined location. The automatic controlled vehicle  11  and the carriage  12  may swivel around the vertical axis Z 1  to change direction. When the automatic controlled vehicle  11  swivel around the vertical axis Z 1 , the casters  21 ,  22 ,  23  and  24  are turned and rotated. Therefore, a large force is applied to the coupling mechanism  13 . 
     Against swiveling around the vertical axis Z 1 , the first roller portion  51  and the second roller portion  52  are constrained by the guide rail section  73 . Further, the third roller portion  53  is fixed by the fitting portion  100  of the lock member  74 . With this structure, the coupling mechanism  13  can exhibit a great deal of strength against the load created when the automatic controlled vehicle  11  and the carriage  12  move relative to each other in back and forth direction or swivel around the vertical axis Z 1 . 
     When implementing the present invention, it is only natural to carry out by remodeling specific embodiments thereof in various ways, for the specific structures of the automatic controlled vehicle and the carriage, as well as, for example, the first to third shaft members, roller portions, guide rail sections, lock members, actuators, etc., which constitute the coupling mechanism. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.