Patent Publication Number: US-2006010833-A1

Title: Contents-filling vessel reversing apparatus

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a contents-filling vessel reversing apparatus for use in a bag packaging machine, namely an apparatus for reversing a vessel accommodating contents to be filled into a container such as, for example, a packaging bag. More specifically, the present invention relates to a contents-filling vessel reversing apparatus for reversing a vessel accommodating contents to be filled into a container from a upright state to an inverted state, thereby dropping downward and filling the contents into a packaging container disposed underneath, when foods or the like are packaged in the packaging container.  
      2. Prior Art  
      In the automatic packaging of foods and the like, filling of contents is usually carried out as follows, namely, vessels accommodating a predetermined amount of contents such as foods or the like to be filled in a packaging container are successively supplied in a upright state, this vessel in the upright state is held by a holding device and the holding device is rotated in a vertical plane around a predetermined center of rotation to reverse the vessel into an inverted state, thereby dropping downward and filling the contents into a packaging container disposed underneath. An example of this kind of the apparatus for reversing a vessel is disclosed in, for example, Japanese Non-examined Patent Application No. 8-282602.  
      With the reversing apparatus disclosed in this publication, a vessel in an upright state is supplied to a vessel accommodation part of the reversing device, this reversing device is rotated 180 degrees around a rotating shaft to reverse the vessel, and the reversing device is once stopped at this position to drop the vessel downward. The vessel collides with and received by a vessel receiving table disposed below, thereby ejecting downwardly the contents accommodated in it.  
      One of alternatives to the arrangement mentioned above is to grip the vessel on the outer circumference thereof or the upper/lower ends thereof by a pair of gripping members capable of approaching to and separating away from each other.  
      In either case, a vessel is reversed by rotating the holding members or gripping members around an axis. For ejecting the contents from a vessel, most of the apparatuses or devices in the prior art comprises arrangements similar to the arrangements disclosed in Japanese Non-examined Patent Application No. 8-282602 where a vessel is discharged and collides with a stopper to eject the contents by making use of the impact caused. There are also some cases where a vessel is not discharged when the holding member is rotated 180 degrees and stopped, while the contents are ejected from the vessel due to a shock caused at the stopping. Even in these cases, the vessel is dropped downwardly after ejection of the contents and stopped and received by a stopper for collection.  
      In the meantime, with a reversing apparatus of this kind, there is a subject of how to set the rotating speed of the holding members or the like used therein. In other words, if the rotating speed is low, the contents in the vessel may run out when the vessel is tilted to a position where the mouth thereof faces obliquely and downwardly during the rotation. This phenomenon may be caused easily especially with solid materials so-called bulky substances and becomes remarkable as the amount of the contents to be filled increases. If the rotating speed is increased in order to prevent this problem and to improve work efficiency, the contents accommodated in the vessel may fly out from the vessel at an undesired position during the rotation in the tangential direction of the rotary trajectory due to increased centrifugal force.  
      Other disadvantages attributable to high-speeding have also been found. Namely, if the rotating speed is increased, an impact caused by collision of the vessel with the stopper becomes great, accordingly resulting in chipping of the vessel and in mixing of fragments into the packaging container. The noise problem due to collision is also serious.  
      According to Japanese Utility Model Registration No. 2539246, a vessel is held on the outer end of an arm and the arm is stopped suddenly when rotated 180 degrees, thereby discharging the contents from the vessel due to inertia force. If the contents to be filled are solid matters, however, the same problems as experienced with the apparatus disclosed in Japanese Non-examined Patent Application No. 8-282602 referred to above will arise. In addition, if a higher speed is employed for contents to be filled with a higher viscosity, they will not drop directly underneath when the arm is stopped, but there is a tendency that they are discharged in a direction along with the rotary trajectory of the arm, which results in the problems that the contents to be filled are adhered to the side wall of a guide.  
     SUMMARY OF THE INVENTION  
      The present invention is made in light of the problems with the prior art as mentioned above. An object of the present invention is to present a contents-filling vessel reversing apparatus by which processing capability can be improved without causing flying out of contents from a vessel even if the rotating speed of the holding member is increased.  
      It is also another object of the present invention to solve the problems such as chipping of the vessels and noise generation resulting from high-speeding as seen in the prior art by adopting arrangements for ejecting contents from the vessel without causing a collision of the vessel directly with a stopper.  
      Among the problems seen in the conventional apparatuses; regarding the problem of flying out of contents from the vessel, the inventors of the present invention paid attention to the fact that, in the conventional apparatuses, the center of rotation of the vessel gripping members is set to the same height as that of the center of a vessel located at the holding position, and found that this could be resolved by setting the center of rotation of the vessel gripping members at a height higher than the center position of the vessel located at the holding position. It has also been found out that it is possible to solve the problems of chipping of the vessels and noise generation by handing a vessel over to a vessel carrying-out apparatus on the way of a process when the holding member is returning back to the original position for receiving a next vessel without dropping the vessel at the position where the vessel is reversed.  
      More specifically, in order to solve the problems and to accomplish the objects mentioned above, the present invention presents a contents-filling vessel reversing apparatus for reversing a contents-filling vessel accommodating contents to be filled from an upright state to a nearly inverted state, thereby dropping downward and filling the contents into a packaging container disposed underneath, said apparatus comprising 
          a vessel holding member for holding said vessel supplied to a holding position, said vessel holding member being designed to rotate in a vertical plane around a center of rotation,     wherein the position of said center of rotation is set higher than the position of the center in the vertical direction of said vessel positioned at said holding position.        

      With these features, the centrifugal force acting on the vessel or the contents in the vessel during the reversing operation is directed obliquely backward with regard to the direction of movement of the vessel, and acts to force the contents toward the bottom of the vessel, thereby preventing the contents from flying out from the vessel. Therefore, even contents with low adhesion, namely so-called bulky substance, can be dealt with at a high rotational speed at which contents could fly out when the conventional apparatus mentioned above is used. If desired, further high-speeding is possible.  
      According to another embodiment of the invention, said holding member comprises a pair of gripping members attached to the rotating device and being capable of approaching to and separating away from each other to grip and to release said vessel, and 
          said apparatus further comprises:     a reversing device including a rotating device equipped with a main rotating member rotatable around said center of rotation, said rotating device rotating intermittently the main rotating member in one direction and stopping the main rotating member at a first and a second positions, and said gripping members attached to said rotating device, said gripping members being designed to stop at a gripping stop position where said gripping members can grip a vessel supplied in said upright state when said main rotating member stops at the first stop position, and to stop at a reversal stop position where said vessel is held in said nearly inverted state when said main rotating member stops at the second position;     a reversal stop position regulating device for regulating said reversal stop position of said gripping members;     an empty vessel carrying-out device provided at an empty vessel discharging position on the way along which said gripping members return from said reversal stop position to said gripping stop position, said empty vessel carrying-out device receiving an empty vessel from which the contents to be filled have been ejected and transferring it to downstream process; and     a gripping member opening/closing apparatus for making said gripping members close to grip a vessel at said gripping stop position and for making said gripping members open at said empty vessel discharging position, thereby discharging the empty vessel towards said empty vessel carrying-out device.        

      In the apparatus with the compositions mentioned above, the gripping members grip a vessel and rotate, and when the gripping members stop at the reversal stop position, the vessel is in a reversed state and stopped, thereby discharging the contents in the vessel due to the inertia force. The empty vessel is still griped by the gripping members even after it is reversed and the contents is discharged, and is released towards the vessel carrying-out device on the way returning to the gripping stop position. Therefore, there is no direct collision of a vessel with a stopper plate as observed in the prior art and problems of chipping of vessels, entry of foreign matters into a packaging container and deterioration of working environments do not occur.  
      Further, the reversal stop position can be regulated to any desired position by the reversal stop position regulating device and, therefore, it is possible to regulate the reversal stop position according to properties and amount of the contents to be filled, processing rate or the like to ensure accurate dropping of the contents into a packaging container disposed directly underneath.  
      According to another embodiment, the main rotating member comprises a main rotating shaft rotating intermittently in one direction every 180 degrees, and the rotating device further comprises a supporting shaft supported by the main rotating shaft in parallel to the main rotating shaft in an axial direction and designed to be reciprocally rotatable around an axis thereof between an initial position and a rotated position. The contents-filling vessel reversing apparatus further comprises a supporting shaft rotating device for rotating the supporting shaft. The reversing stop position regulating device regulates the rotated position of the supporting shaft, and the pair of gripping members are mounted on one end of the supporting shaft.  
      With these compositions mentioned above, the supporting shaft rotating device is designed to change the relative position of the supporting shaft to the main rotating shaft in the direction of rotation by turning the supporting shaft. Therefore, even when two sets of gripping members are provided and these are rotated intermittently every 180 degrees by the reversing device, it is possible to change the reversal stop position while the gripping stop position is fixed.  
      As noted, the supporting shaft is rotated during the reversal operation. By setting appropriately the way of rotating of the supporting shaft, for example by not tilting the vessel greatly at the earlier stage of reversal and tilting the vessel rapidly and greatly at the last end stage of reversal, depending on type, properties, and amount of contents to be filled, it is possible to prevent the contents from flying out from the vessel at an stage earlier than desired.  
      According to another embodiment of the present invention, the supporting shaft is formed to be hollow, and the gripping member opening/closing device comprises a sliding shaft inserted into the hollow section of the supporting shaft and movable in the axial direction. The sliding shaft is connected at one end to the gripping members, and the gripping members are opened and closed interlockingly with the axial direction movement of the sliding shaft.  
      According to the composition mentioned above where a sliding shaft is disposed within a supporting shaft, peripheral arrangement of the reversal mechanism of the apparatus can be made compact, and ease of cleaning is improved.  
      According to another embodiment, the supporting shaft rotating device is equipped with a grooved cam securely positioned with an axis thereof coinciding with the axis of said main rotating shaft, a lever fixed to the other end of said supporting shaft and a cam roller mounted on the lever so as to roll in and move along a groove formed in the grooved cam. Further, in a predetermined range in the groove extending in the opposite directions from a position corresponding to the rotated position of the supporting shaft, at least a radius of curvature of an inner wall of said groove is made shorter than a radius of curvature of the inner wall in a rest range in the groove so that a width of the groove in said predetermined range is larger than a width of the groove in the rest range. Still further, the reversal stop regulating device is provided with a positioning stopper which abuts against the lever to position the lever at the reversal stop position, and a stopper position regulating device for regulating the position of the stopper.  
      According to the compositions mentioned above, it is possible to change the reversal stop position only by adjusting the position of the stopper, and the gripping stop position is unchanged even when the reversal stop position is changed. Therefore, the adjustment can be done easily.  
      According to yet another embodiment of the present invention, two supporting shafts are provided symmetrically with respect to the axis of the main rotating shaft, and each of the supporting shafts is provided with a pair of the gripping members. Therefore it is possible to improve processing capability of the apparatus.  
      As noted above, according to the present invention, even in the case the contents to be filled are ones with low adhesion, namely so-called bulky substance, it is possible to prevent the contents from flying out from the vessel during rotation even when rotated at a high rotational speed, thereby improving processing capability. With the conventional art mentioned above, when dealing with relatively large amount of bulky contents, spilling out or flying out of the contents happens at any rotational speed and therefore, complete filling is not possible. According to the present invention, however, filling of such a large amount of bulky contents can be done surely. Besides, chipping of the vessel in use can be prevented, thereby preventing entry of foreign matters into the packaging container, and noise generation can be reduced, thereby contributing to improvement of working environments. Moreover, it is possible to drop, at the reversal position, contents surely into a packaging container disposed underneath. Regulations for this purpose can also be done easily. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a partly sectioned front view showing a apparatus for reversing a vessel accommodating contents to be filled according to a preferred embodiment of the present invention,  
       FIG. 2  is a partly sectioned plan view thereof,  
       FIG. 3  is a partly sectioned right side view thereof,  
       FIG. 4  is a rear view showing the principal part of the apparatus,  
       FIG. 5  is a plan view showing a stopper mechanism,  
       FIG. 6  is a right side view showing the principal part of the stopper mechanism, and  
       FIG. 7  is a diagrammatic view showing relationship between the height of the center of rotation of the vessel and the height of the center of the vessel. 
    
    
     DETAILED EXPLANATION OF PREFERRED EMBODIMENTS  
      Referring now to the drawings, a preferred embodiment of the present invention will be explained hereinafter.  FIG. 1  is a partly sectioned front view showing a contents-filling vessel reversing apparatus  1  (referred to simply as “apparatus” hereinafter) for reversing a contents-filling vessel (referred to simply as “vessel” hereinafter) accommodating contents to be filled according to a preferred embodiment of the present invention.  FIG. 2  is a sectional plan view,  FIG. 3  is a partly sectioned side view, and  FIG. 4  is a rear view showing the principal part of the apparatus. According to the present embodiment, two sets of mechanisms for gripping and reversing a vessel Y are provided as will be described hereinafter.  
      The apparatus  1  has a machinery mount  2 . A stand  3  is erected on the machinery mount  2 , and a frame  4  in a nearly box-shaped configuration is secured on the stand  3 . Two vertical wall portions  5 ,  6  are formed in parallel with and separated from each other above and below at the lower part of the frame  4  as viewed in  FIG. 2 . The walls form supporting parts  5 ,  6  for a main rotating shaft  7 . The main rotating shaft  7  is supported through bearings  8 ,  8  disposed at the opposite ends thereof. Two through holes are formed through the shaft  7  at right and left symmetrical positions with respect to the center of the main rotating shaft  7 . Supporting shafts  9 ,  10  are inserted through the through holes, respectively, and are rotatably supported by bearings  11  disposed at the opposite ends of the main rotating shaft  7 , respectively. (For convenience of explanation, one shown at the left in  FIG. 2  is referred to as a first supporting shaft  9  while one shown at the right is referred to as a second supporting shaft  10 . When no discrimination is needed or they are identified unmistakably, however, they are simply referred to as supporting shaft  9  or supporting shaft  10 .) The supporting shafts  9 ,  10 , and members associated therewith and constructions thereof are identical. Therefore, the following description mainly deals with the supporting shaft  9  and the associated members only.  
      In the figures, the supporting shaft  9  and the associated members are at a gripping stop position capable of gripping a vessel Y, while the supporting shaft  10  and the associated members are at a reversal stop position, i.e. vessel Y is in a nearly inverted state. The vessel Y according to the present embodiment is a cylindrical vessel having a bottom and is supplied successively by a supply conveyor  71  to the position shown (see  FIG. 1 ).  
      A through hole is formed through the supporting shaft  9 , and a sliding shaft  12  is inserted through this through hole. Although the sliding shaft  12  is movable in the axial direction, no turning is possible. One end of the sliding shaft  12  (lower side in  FIG. 2 ) is projected from the supporting shaft  9 , and a cylindrical part  14  formed at the base part of a gripping member supporting block  13  is fitted on this projecting portion. The block  13  is fixed to an flange part  9   a  formed at one end of the supporting shaft  9 . The supporting block  13  is equipped with a fork part  15 , and a left gripping member  16  and a right gripping member  17  which rotate together with supporting pins  16   a ,  17   a , respectively, are mounted on the respective tip ends of the fork part  15 .  
      A link linkage member  18  is securely mounted on the end of the sliding shaft  12  projecting from the cylindrical part  14  of the gripping member supporting block  13 . On the opposite side surface of the cylindrical part  14 , one end of a link  18   a  is rotatably connected to the link linkage member  18  (see the second supporting shaft  10  and the associated members in  FIG. 2 .), and one end of connecting arm part  17   b  of the right gripping member  17  is rotatably connected to the other end of the link  18   a . An engagement pin  19  is fixed to stand on an engagement arm part  17   c  of the right gripping member  17  extending in a direction nearly orthogonal to the connecting arm part  17   b , and an elongated hole  16   c  formed through a linking arm part  16   b  of the left gripping member  16  is fitted to this pin  19  so that a motion is transmitted between both gripping members  16 ,  17 .  
      A spring receiving part  12   a  with an increased diameter is formed on the sliding shaft  12  at a portion inside of the cylindrical part  14  of the gripping member supporting block  13 , and a compression spring  20  is disposed between this receiving part  12   a  and an inside end face of the cylindrical part  14  of the supporting block  13 . Therefore, this spring acts to urge the right and left gripping members  16 ,  17  in the closing direction.  
      A roller  21  is attached to the opposite end of the sliding shaft  12  through an attachment shaft  22 . With regard to this roller  21 , a gripping member opening/closing cam  25  is disposed and securely mounted on the front end of a rod  24   a  of an air cylinder  24  that is mounted on the frame  4  through an attachment bracket  23 . The opening/closing cam  25  is in the shape of a nearly semicircle ring (see  FIG. 4 ), and a face thereof facing the roller  21  comprises flat part  25   a  and inclined part  25   b . The inclined part  25   b  inclines in a direction where it is gradually separated away more from the roller  21  as going towards the end thereof (see  FIGS. 2 and 4 , in this condition illustrated, the roller  21  associated with the first supporting shaft  9  is placed on the flat part  25   a  and the roller  21  associated with the second supporting shaft  10  is disengaged from the cam  25 ).  
      When the main rotating shaft  7  is in the stationary state and the first supporting shaft  9  and the associated sliding shaft  12  are in the position shown in  FIG. 2 , the air cylinder  24  is actuated to retract its rod  24   a , the cam  25  is moved backwardly, and the gripping members  16 ,  17  are closed, thereby gripping the vessel Y. The main rotating shaft then starts to rotate (in the present embodiment, it rotates in the clockwise direction as viewed in  FIG. 1  and in the counterclockwise direction as viewed in  FIG. 4 ). And when the roller  21  associated with the first supporting shaft  9  is disengaged from the cam  25 , the air cylinder  24  is actuated in the reverse direction, thereby returning the cam  25  to its original position. As will be described later, after the main rotating shaft  7  is stopped at the reversal stop position where the vessel Y is reversed (in the drawings, the second supporting shaft  10  is in this position), and when it resumes rotating in the same direction in order to return to the gripping stop position, the roller  21  is rested on the inclined part  25   b  of the cam  25  on the way of returning, and then on the flat part  25   a , thereby opening again gripping members  16 ,  17 . This will be described again later.  
      Next, a mechanism for reversing the vessel Y will be described. Numeral  31  denotes a motor mounted on the main rotating shaft supporting part  6  of the frame  4  (see  FIG. 2 ). An output shaft  32  of the motor  31  extends through the supporting part  6 , and a driving gear  33  located between the supporting parts  5  and  6  is fixed to the front end thereof. This driving gear  33  meshes with a driven gear  34  fixed to the main rotating shaft  7 . According to the present embodiment, the motor  31  turns intermittently in the same direction to rotate the main rotating shaft  7  every 180 degrees in the clockwise direction as viewed in  FIG. 1  and in the counterclockwise direction as viewed in  FIG. 4 . In this case, the supporting shafts  9 ,  10  are also rotated in one around the center of the main rotating shaft  7 . Therefore, the vessel Y gripped by the gripping members  16 , 17  attached to the supporting shafts  9 , 10  also rotate around the axis of the main rotating shaft  7 . As clearly illustrated in  FIG. 1 , the axis of the main rotating shaft  7 , and, therefore, also the center of rotation of the gripping members  16 , 17  is situated at a position higher than the center in the vertical direction of the vessel in the upright state supplied to the gripping stop position. This point will be explained later again.  
      In  FIG. 2 , a cam lever  35  is fixedly secured at one end thereof to the end part of the supporting shafts  9  ( 10 ) projecting upwardly from the main rotating shaft  7  (see  FIG. 4 ). A cam roller  36  is mounted on the other end of the lever  35 . Corresponding to these cam rollers  36 , a grooved cam  37  is fixed to the main rotating shaft supporting part  6 . A groove  38  is formed on the cam  37  and the cam roller  36  is fitted in and rolls along the groove  38 . The groove  38  is provided with a uniform part  38   a  where the inside and outside walls  39  and  40  of the groove  38  are concentric with each other, having its center at the center of the main rotating shaft  7 . The width of the uniform part  38   a  of the groove  38  nearly corresponds to the diameter of the cam roller  36 . The groove  38  is also provided with an enlarged part  38   b  with an increased width. Namely, the inside wall  39  has a concentric part  39   a , and a displacement part  39   b  where the radius of curvature is decreased gradually and is increased gradually again as going in the counterclockwise direction from the left upper part to the lower part in  FIG. 4 . Further, the outside wall  40  has a concentric part  40   a , and a displacement part  40   b  where the radius of curvature is increased gradually and is decreased again at the upper part. Therefore, the supporting shafts  9 ,  10  are unable to rotate as long as the cam roller  36  is located in the uniform part  38   a  while rotating is possible in the enlarged part  38   b.    
      In  FIG. 4 , corresponding to the end part of the cam lever  35  associated with the second supporting shaft  10  on which end part the cam roller  36  is mounted, there is a stopper mechanism  45  for regulating the stop position or the reversal position of the gripping members  16 ,  17  mounted on this cam lever  35  and, thus the position of the second supporting shaft  10 .  
      In addition to  FIG. 4 , referring to  FIGS. 5 and 6 ,  FIG. 5  is a plan view showing details of the stopper mechanism  45  and  FIG. 6  is its right side view. Numeral  46  denotes a rail of the stopper mechanism  45  that is secured to the main rotating shaft supporting part  6  of the frame  4 . In  FIGS. 4 and 5 , a slide member  47  is mounted on the rail  46  to be movable in the lateral direction as viewed in  FIGS. 4 and 5 . A slide plate  48  is fixed integrally on the slide member  47 , a stopper roller  50  is mounted on the left side end part of the slide plate  48  as viewed in  FIG. 5  by a supporting shaft  49 , and a contacting part  51  contacting a shock absorber  52  (which will be described later) is provided on the slide plate  48  to stand on the right side of the roller  50 . Responding to the contacting part  51 , the shock absorber  52  is mounted on the main rotating shaft supporting part  6  through a bracket  54 . The contacting part  51  of the slide plate  48  is provided to contact with a contacting shaft  53  of the shock absorber  52 . The position of this shock absorber  52  is adjustable in the axial direction of the contacting shaft  53 .  
      When the main rotating shaft  7  starts to rotate from the state shown in  FIG. 1 , etc., the first supporting shaft  9  is unable to rotate around its axis during an early stage, since the cam roller  36  on the cam lever  35  attached to the shat  9  moves along and rolls in such a portion where the width of the groove  38  of the cam  37  is uniform, and the shaft  9  simply rotates or does a revolution around the axis of the main rotating shaft  7  integrally with the main rotating shaft  7 . When the cam roller  36  comes to the displacement part  40   b  of the outside wall  40  of the groove  38  and further to the displacement part  39   b  of the inside wall, the width of the groove  38  becomes greater than the diameter of the cam roller  36 . In this occasion, due to a load exerted to the supporting shaft  9 , the cam roller  36  moves in such a manner that the cam roller  36  rolls on the inside wall  39   b , and the cam lever  35  and the supporting shaft  9  rotate around the axis of the supporting shaft  9  in the clockwise direction as viewed in  FIG. 4 . In other words, the cam lever  35  and the gripping members  16 ,  17  attached to the lever  35  rotate around the axis os the main shaft  7  in a slightly delayed state with regard to the main rotating shaft  7 .  
      When the main rotating shaft  7  is turned 180 degrees and is stopped, the cam lever  35  and the supporting shaft  9  now rotate counterclockwise around the axis of the supporting shaft  9 , since the gripping members  16 ,  17  continue their motion due to the inertia force. The end part of the cam lever  35  on which the cam roller  36  is mounted collides with the stopper roller  50  described previously, and the cam lever  35 , and thus the supporting shaft  9  also stop while the impact is being absorbed by the shock absorber  52 . In FIGS.  1  to  4 , the second supporting shaft  10  and the associated members are corresponding to this state. On this occasion, the vessel Y stops suddenly in a nearly reversed state as shown in  FIG. 1 , thereby discharging the contents accommodated in it into a guide cylinder  56  located underneath. As illustrated, the vessel Y is not in a completely inverted state. This is because considerations are given to the direction along which the contents in the vessel Y are discharged at the sudden stop of the vessel Y, which considerations are dealt with in the description of the prior art mentioned above. The direction of discharging can be set in the optimum state by regulating the final stop position of gripping members  16 ,  17 , i.e., the reversal stop position, by regulating the position of the shock absorber  52  of the stopper mechanism  45  described previously.  
      Next, the main rotating shaft  7  again resumes rotating in the same direction at a predetermined timing, and the second supporting shaft  10  positioned at the reversal stop position in the figures starts returning movement to the gripping stop position described previously where the first supporting shaft  9  exists in the figures. As the main rotating shaft  7  rotates, the supporting shaft  10  rotates together with the main rotating shaft  7  in such a manner that the cam lever  35  presses the shock absorber  52  through the stopper roller  50 , and the cam lever  35  is disengaged from the stopper roller  50 . When the cam roller  36  rolls on and moves along such a portion where the radius of curvature of the displacement part  39   b  of the inside wall  39  of the groove  38  becomes greater gradually, the supporting shaft  10  rotates by a predetermined angle in the direction opposite to the previous one, and the positional relationship between the supporting shaft  10  and the main rotating shaft  7  is restored to the original state.  
      Meanwhile, when the main rotating shaft  7  rotates in this returning process, the roller  21  attached to the sliding shaft  12  described previously rests on the inclined part  25   b  of the gripping member opening/closing cam  25  also described previously, and then rides on the flat part  25   a  at a predetermined turning position to open the gripping members  16 ,  17 , thereby discharging the vessel Y having being gripped till then. This is the vessel discharging position, at which a vessel carrying-out apparatus  61  is disposed for receiving emptied vessels and transferring them to downstream process (see  FIGS. 1, 3 ). The operations of discharging the vessel Y are carried out while the main rotating shaft  7  continues rotating.  
      The vessel carrying-out apparatus  61  is equipped with an empty vessel collection conveyor  62 , and a vessel collection guide  63  is mounted on the stand  3  by a bracket  64 . The guide  63  extends between a receiving side end of the conveyor  62  and a cutout  56   a  formed through the guide cylinder  56 . The vessel Y being griped by the gripping members  16 ,  17  can pass through the cutout  56   a . The gripping members  16 ,  17  open, and the empty vessel Y discharged and received on the empty vessel collection guide  63  moves onto the conveyor  62  and is transferred to downstream process while being guided by guide bars  65 . The main rotating shaft  7  continues rotating, and stops after rotated by 180 degrees, while the gripping members  16 ,  17  return to the gripping stop position in the opened state.  
      Referring to  FIG. 7 , detailed explanation will be given regarding the arrangement where the axis of the main rotating shaft is situated at a position higher than the center of a vessel in the upright state supplied to the gripping stop position. In  FIG. 7 , symbols O and O′ respectively denote the center of rotation of the gripping members  16 , 17  employed in the present invention and the center of rotation of the gripping members  16 , 17  employed in the conventional reversing apparatus with respect to the vessel Y supplied to the same gripping stop position. The figure shows the manner of the rotation of the vessel Y in the present invention which is shown by solid lines and of the vessel Y′ in the conventional apparatus which is shown by double dashed chain lines. Centrifugal force acting in each case is indicated by arrows V and V′, respectively.  
      As it is apparent from  FIG. 7 , in the conventional case, when vessel Y′ is rotated, the direction of centrifugal force V′ acting on vessel Y′, i.e., on the contents inside, is orthogonal to the direction of movement of the vessel Y′. In contrast, in the embodiment of the present invention, it is oriented obliquely backward with regard to the direction of movement of the vessel Y In other words, the centrifugal force V generated in the present invention acts to force the contents in the vessel Y toward the part of the cylindrical side wall of the vessel farther from the center of rotation of the vessel Y and, therefore acts to force the contents toward the bottom of the vessel Y Namely, the contents in the vessel Y are forced in the direction opposite to the direction of the movement of the vessel Y, thereby preventing the contents from flying out from the vessel Y during rotating. When the center of rotation of the main rotating shaft  7  is situated at a position higher than that shown in  FIGS. 1 and 7 , the direction of action of the centrifugal force V is tilted further to the left in  FIG. 7 , thereby enhancing tendency of forcing the contents toward the bottom of the vessel Y.  
      In the embodiment mentioned above, the gripping members  16 ,  17  which grip the vessel on the outer circumference thereof in cooperation are used as a holding member for folding the vessel Y. Alternatively, however, these members may be such a type of gripping members that grip the vessel on the upper and lower ends thereof. Further, this is not limited to the embodiment where a pair of gripping members are used, and, for example, a reversing apparatus (holding member) disclosed in Japanese Non-examined Patent Application No. 8-282602 given as an example of conventional art may be used.  
      According to the present embodiment described above, it is designed that the rotating speed of the motor  31  changes with two steps mode during one operation. In other words, since discharging an empty vessel Y at too high speed may cause problems, a relatively low-speed is employed in the stages before completion of discharging of the vessel, and then the speed is shifted to a higher speed after discharging the vessel, thereby ensuring reliable and thorough ejection of the contents accommodated in the vessel Y at the reversal stop position.  
      Although, according to the embodiment described above, two supporting shafts are provided and two sets of gripping members are used for one main rotating shaft, when one set of gripping members is used, the gripping members can be mounted directly on the main rotating shaft. On this occasion, a servo motor may be used as a driving motor for appropriately regulating the rotational angle from the gripping stop position to the reversal stop position and the rotational angle in the returning process from the reversal stop position to the gripping stop position, so that the stopper mechanism used in the embodiment described above is unnecessary.