Abstract:
A contents-filling apparatus for use in a bag packaging machine. The apparatus comprises a reversing device including a rotating device for rotating intermittently a main rotating member around an axis thereof in one direction and for stopping the rotating member at a first and a second positions, and a pair of gripping members attached to the rotating device and being capable of gripping and releasing said vessel. The gripping members are designed to stop at a gripping stop position where said gripping members can grip a vessel in an upright state when said main rotating member stops at the first stop position, and stop at a reversal stop position where said vessel is held in a nearly inverted state when said main rotating member stops at the second positions. The apparatus further comprises a reversal stop position regulating device for regulating said reversal stop position, an empty vessel carrying-out device provided at an empty vessel discharging position on the way along which said gripping members returns from said reversal stop position to said gripping stop position, said empty vessel carrying-out device receiving an empty vessel and transferring it to downstream process; and a gripping member opening/closing apparatus for making said gripping members close to grip a vessel and for making said gripping members opens, thereby discharging the empty vessel towards an empty vessel carrying-out device.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     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. The present invention also relates to a contents-filling vessel for accommodating contents to be filled into a packaging container which vessel are suitable for use with the contents-filling vessel reversing apparatus.  
         [0003]     2. Prior Art  
         [0004]     In automatic packaging of foods and the like, filling of contents to be filled is usually carried out in such manner that vessels each accommodating a predetermined amount of contents such as foods or the like to be filled into a packaging container are supplied successively, this vessel is griped by such as, for example, a pair of gripping members which are capable of approaching to and separating away from each other, then the vessel is reversed from an upright state to a reversed state by rotating these gripping members in a vertical plane around a predetermined axis to drop the contents in the vessel into a packaging container disposed underneath. An example of the reversing apparatus of this type is described in, for example, Japanese Utility Model Publication No. H 7-20007.  
         [0005]     With a reversing apparatus described in this publication, a vessel is held by gripping members provided at one end of an rotating arm and the vessel is reversed from an upright state to an inversed state by rotating the arm by approximately 180 degrees, and the vessel still in a being accelerated state is released at this reversed position. The vessel is then hit and stopped by such as a stopper plate or the like to discharge the contents contained in the vessel downwardly. Therefore, a big impact noise is generated at hitting, thereby resulting in one of causes responsible for deteriorated working environments. Further, the vessel may be chipped in part when hitting on the stopper, which may poses a problem that fragments generated are mixed into the packaging container (vessels made of resin are used in many cases).  
         [0006]     Next, according to Japanese Patent Publication No. 2929476, a cushion member made of, for example, rubber or the like is provided at the stopper portion. Although the impact noise is reduced to a certain extent, this attempt is still not deemed satisfactory. Due to repeated hitting, the rubber as the cushion member as well as the vessel are worn and in some cases, fragments are mixed into the contents to be filled. Besides, in the case viscosity of the contents is relatively high, discharging of the contents from the vessel may become imperfect due to the cushioning action of the cushion member.  
         [0007]     According to Japanese Utility Model Laid-open No. 2539246, when an arm stops at the position rotated by 180 degrees, contents in the vessel are discharged downwardly due to inertia force. The vessel is then released to drop downward, and stopped by hitting a stopper plate. Although, compared with the above-mentioned two examples, the problems associated with the impact is relaxed, this proposal does not present a perfect solution. If the reversing speed is increased in an attempt to improve the processing capability of the apparatus and to accomplish perfect discharge of the contents from the vessel, the contents discharged from the vessel do not drop directly downward when the arm is stopped, but rather tend to be discharged in the direction along with the arm rotating trajectory. In the result, adhesion of the contents to the side wall of the guide may take place, thereby causing another problem that the contents are not filled surely into the packaging container.  
         [0008]     For the vessel used in the conventional contents-filling vessel reversing apparatus including the above-mentioned examples, the vessels usually have a smooth outer circumference, upper and lower end faces free from projections and depressions. In the meantime, engaging surfaces of a pair of gripping members for gripping the vessel is also formed smooth. Therefore, it is necessary to grip the vessel with a considerably strong force in order to prevent the vessel from slipping off from the gripping members when the vessel is reversed. In some cases, a small portion of the contents may adhere onto the outer circumference of the vessel. Especially when the contents contain oily substance, the strength of the gripping force should be set at a higher level. Accordingly, wear of the vessel becomes excessive and durability becomes poor. Besides, there is a possibility that foreign matters generated by wear are mixed into the contents.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention is made in light of the problems with the prior art as mentioned above. The object of the present invention is to present a contents-filling vessel reversing apparatus capable of discharging the contents from the vessel without hitting it against a stopper or the like, thereby preventing generation of noises to realize favorable working environments, and in addition, avoiding breakage of the vessel and preventing entry of fragments of the vessel into the contents to be filled.  
         [0010]     It is another object of the present invention to present a contents-filling vessel reversing apparatus that enables improvement of the processing capability and ensures filling of contents into a packaging container regardless of the type, properties and amount of the contents to be filled.  
         [0011]     Further it is another object of the present invention to present a contents-filling vessel reversing apparatus that does not need so strong gripping force as required in the conventional apparatus and enables improvements of wear and durability of contents-filling vessels used.  
         [0012]     Still another object of the present invention is to present a contents-filling vessel for accommodating contents to be filled into a packaging container which can be used favorably with the above-mentioned contents-filling vessel reversing apparatus.  
         [0013]     In order to solve the problems as discussed above and to accomplish the objects mentioned above, the present invention presents: 
        a contents-filling vessel reversing apparatus for reversing a vessel accommodating contents to be filled from a upright state to a nearly inverted state, thereby dropping downward and filling the contents into a packaging container disposed underneath, said apparatus comprising:     a reversing device including a rotating device equipped with a main rotating member rotatable around an axis thereof for rotating intermittently the main rotating member in one direction and for stopping the main rotating member at a first and a second positions, and 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, 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 the empty vessel carrying-out device.        
 
         [0019]     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.  
         [0020]     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.  
         [0021]     According to one 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.  
         [0022]     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.  
         [0023]     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.  
         [0024]     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.  
         [0025]     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.  
         [0026]     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.  
         [0027]     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.  
         [0028]     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.  
         [0029]     According to yet another embodiment of the present invention, the gripping members grip the vessel on the outer circumference thereof. The vessel is provided with a thin strip projection or a groove formed on the outer circumference and extending over the entire circumference of the vessel, while each of the gripping members is provided with a groove or a thin strip projection formed on the gripping face opposing to the vessel to engage with the thin strip projection or the groove on the vessel. This configuration ensures gripping of the vessel, and the vessel would not disengage erroneously from the gripping members. Therefore, it is not necessary to grip the vessel with excessively strong force, thereby preventing breakage or the like of the vessel. Further, projections or grooves having a nearly circular or trapezoidal section can make reliable and stable the engagement between the thin strip projection and the groove respectively provided on the vessel and gripping members. Besides, if a groove is formed on the vessel, breakage of the vessel due to collision of fellow thin strip projections of adjacent vessels as may be observed when the thin strip projection is formed on the vessel can be avoided.  
         [0030]     According to yet another embodiment of the present invention, the rotational speed of the main rotating member changes with at least two steps mode. A low speed may be employed during a first movement stage when the gripping members move from the reversal stop position to the vessel discharging position, and a speed higher than that of the first movement stage may be employed during a second movement stage when the gripping member move later to the gripping stop position. This make it possible to perform reliable delivery of an empty vessel to the empty vessel carrying-out device as well as reliable ejection of the contents from the vessel.  
         [0031]     In addition, the present invention presents a contents-filling vessel for accommodating contents to be filled for preferable use with the above-mentioned contents-filling vessel reversing apparatus. The vessel is provided with a groove or a thin strip projection formed on the outer circumference thereof and extending over the entire circumference thereof.  
         [0032]     In one embodiment, the sectional profile of the groove or thin strip projection is nearly semicircular or trapezoidal in section.  
         [0033]     As discussed above, according to the present invention, breakage of a vessel during operation can be prevented and entry of foreign matters into packaging containers can be prevented. Further, noise generation can be reduced, which contributes to improvement of working environments. Furthermore, it is possible to prevent the contents in the vessel from erroneously flying out from the vessel at an undesired stage during operation, and the contents can be dropped surely into a packaging container located directly below the reversal position. Adjustments for this purpose can easily be done. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0034]      FIG. 1  is a partly sectioned front view of a contents-filling vessel reversing apparatus according to a preferred embodiment of the present invention,  
         [0035]      FIG. 2  is a partly sectioned plan view thereof,  
         [0036]      FIG. 3  is a partly sectioned right side view thereof,  
         [0037]      FIG. 4  is a rear view showing the principal portion of the apparatus,  
         [0038]      FIG. 5  is a plan view showing a stopper mechanism used in the apparatus,  
         [0039]      FIG. 6  is a right side view of the stopper mechanism,  
         [0040]      FIG. 7   a  is a sectional view of a contents-filling vessel used with the apparatus, and  
         [0041]      FIG. 7   b  is a sectional view showing another embodiment of a contents-filling vessel.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0042]     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.  
         [0043]     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.  
         [0044]     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 ).  
         [0045]     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 .  
         [0046]     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 .  
         [0047]     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.  
         [0048]     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 ).  
         [0049]     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.  
         [0050]     Referring to  FIG. 7 , the vessel Y and the gripping members  16 ,  17  will be described. The vessel Y is different from the conventional vessels which are formed with a smooth outer circumference. Namely, the vessel Y has, as shown in  FIG. 7   a , on its outer circumference, a groove Ya with a nearly semicircular section extending entirely in the circumferential direction, and corresponding to this configuration, thin strip projections  16   d ,  17   d  with a nearly semicircular section are respectively formed on the inside surface of the gripping members  16 , 17  for gripping the vessel Y When the vessel Y is griped by the gripping members  16 ,  17 , these projections  16   d ,  17   d  are engaged with the groove Ya, thereby enabling the member  16 , 17  to grip the vessel Y more securely compared with the conventional vessels, and the vessel Y would not disengaged erroneously from the gripping members  16 , 17 . Therefore, there is no need for gripping the vessel Y with an excessive force. Profiles of groove Ya and the projections  16   d , 17   d  are not limited to the semicircular shape. For example, a trapezoidal section as shown in  FIG. 7   b  may be employed. Further, a projection may be provided on the vessel Y while grooves may respectively be formed on the gripping members  16 , 17 . The groove Ya according to the present embodiment is formed at a position lower than the center in the height direction of the vessel.  
         [0051]     Referring again to FIGS.  1  to  4 , 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 .  
         [0052]     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.    
         [0053]     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 .  
         [0054]     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 .  
         [0055]     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 of the main shaft  7  in a slightly delayed state with regard to the main rotating shaft  7 .  
         [0056]     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 consideration is 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.  
         [0057]     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.  
         [0058]     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.  
         [0059]     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.  
         [0060]     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, 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.  
         [0061]     According to the embodiment described above, two supporting shafts are provided and two sets of gripping members are used for one main rotating shaft. However, when only 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.