Abstract:
A feeder system for feeding objects to object-carriers of a machine for processing the objects, in particular a printing machine, includes a reciprocating finger for pushing each object directly towards an object-carrier to place the object on the object-carrier; the finger being carried by a reciprocating carriage slidably mounted on a chassis and rotatably mounted on the carriage so that it can occupy at least an operational position in which it can push an object when it is moved and a retracted position in which it can avoid an object when it is moved.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to machines for processing objects, for example printing machines including a turret, which can rotate about its axis and which carries a plurality of object-carriers radially at its periphery via supports which are in turn rotatably mounted on the turret, and a plurality of workstations distributed circumferentially around the turret, in line with the trajectory of the object-carriers, and some of which are printing stations while others are processing stations, for example drying, varnishing, flame treatment, dust removal or other stations. 
     DESCRIPTION OF THE RELATED ART 
     The printing machines are used to print circular objects, for example, such as flexible tubes made of synthetic or other materials and to be printed with several different colours in succession; in this case the object-carriers are cylindrical mandrels onto which the objects are threaded. 
     Feeder systems are of course provided for feeding the object-carriers with the objects. 
     Until now the feeder systems have included a finger, generally of cylindrical shape, reciprocating along its axis and adapted to push each object directly towards an object-carrier. 
     Although these systems operate well, they nevertheless have the disadvantage that, to access the next object to be pushed, the finger must be retracted by a distance at least equal to the length of the object, and that it is only after this movement, which frees the space for the next object, that the next object can take up its place. 
     SUMMARY OF THE INVENTION 
     The subject matter of the present invention is a feeder system in which the next object to be pushed takes up its place before the finger has effected its retraction stroke, which increases the feed rate. 
     In accordance with the invention, a feeder system for feeding objects to object-carriers of a machine for processing the objects, in particular a printing machine, said system including a reciprocating finger for pushing each object directly towards an object-carrier to place the object on said object-carrier, is characterised in that said finger is carried by a reciprocating carriage slidably mounted on a chassis and is rotatably mounted on said carriage so that it can occupy at least an operational position in which it can push an object when it is moved and a retracted position in which it can avoid an object when it is moved. 
     Said finger is advantageously also subjected to the action of spring means which urge it towards its retracted position and locking means are provided for temporarily retaining the finger in its operational position against the action of the spring means. 
     The finger is preferably fastened to a shaft rotatably mounted on the carriage and the spring means comprise a spiral spring wound around said shaft. 
     The locking means advantageously comprise a plunger mounted to slide in a direction orthogonal to the rotation axis of the finger. 
     In the position of the plunger in which the shaft is locked relative to the carriage the outside surface of the plunger preferably cooperates with a flat surface formed on the shaft. 
     The plunger advantageously has a peripheral groove which in the position in which the shaft is unlocked is in line with said flat surface. 
     The carriage preferably reciprocates between two abutments carried by the chassis. 
     The plunger is advantageously adapted to cooperate with the abutment in its locking position and with the abutment in its unlocking position, the carriage being in line with said abutments in each of those positions. 
     The finger preferably includes an operational position selector ramp adapted to cooperate with a fixed roller carried by the chassis. 
     The invention also provides a machine, in particular a printing machine, including object-carriers and a feeder system for feeding the object-carriers with objects, characterised in that the feeder system is a system as defined above. 
     The objects are advantageously carried by an inclined table. 
     The objects are preferably retained by a rim of the table and the rim is parallel to the rotation axis of the finger. 
     Said finger is advantageously generally C-shaped and straddles said rim. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To explain further the subject matter of the invention, an embodiment of the invention shown in the accompanying drawings will now be described by way of purely illustrative and non-limiting example. 
     In the drawings 
     FIG. 1 is a partial elevation view of a machine equipped with a feeder system according to the invention; 
     FIG. 2 is a partial view of FIG. 1 showing in section a carriage carrying a finger; 
     FIG. 3 is a partial bottom view relative to FIG. 1 showing a drive link of the carriage; 
     FIG. 4 is a partial view as seen in the direction of the arrow IV in FIG. 1; and 
     FIGS. 5 to  10  are views analogous to FIG. 4 showing various steps in the operation of the feeder system. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The figures show, by way of example, the application of the invention to the situation in which the objects to be printed are flexible tubes, for example, intended to contain a more or less paste-like product, such as cream, which tubes include a body and a bottom. The body is globally cylindrical and its cross section is substantially circular. 
     The printing machine used to print these objects, only part of which is shown in the figures, is of the type described in U.S. Pat. No. 6,164,199, for example, and globally comprises, as known in the art, a turret which is rotatable on a frame about is axis, which in this instance is a vertical axis, and which carries radially at its periphery a plurality of object-carriers each of which is in turn rotatably mounted on the turret by means of a respective support, their rotation axes being orthogonal to the axis of the turret in this example, and therefore horizontal. 
     The turret is generally a simple circular contour plate rotatably mounted on a table that is part of the frame. This is known in the art. 
     The turret is driven stepwise in rotation by a motor associated with an indexing device. This is known in the art. 
     Because the objects to be printed are flexible tubes, the object-carriers are cylindrical mandrels onto which the objects are simply threaded. 
     The corresponding arrangements are well known in the art and are not described in more detail here. 
     The printing machine includes a plurality of workstations which are circumferentially distributed around the turret in line with the trajectory of the object-carriers and some of which are printing stations while others are processing stations. This is known in the art. 
     The system is completed by a loading and offloading station and workstations for processing the objects before they are printed, for example a flame treatment and dust removal station and a varnishing station followed by a drying station. 
     The machine includes a feeder system shown in FIGS. 1 to  4  adapted to feed objects to the object-carriers. 
     The cylindrical objects  10  are perpendicular to the plane of FIGS. 1 and 2 and are placed on an inclined table  23 ; they are caused to come into contact with each other by their weight alone, with the first object  10 A abutted against a transverse rim  24  of the inclined table  23 . 
     A feed finger  11  is carried by a carriage  12  slidably mounted on a chassis  13 . The carriage  12  reciprocates; to this end, it is fastened by arms  26  to a sled  27  in turn slidably mounted on a rail  28 ; the sled  27  is coupled to a link  29  in turn coupled to a crank  30  (see FIG. 3) fastened to the shaft  36  of a motor incorporated in the machine. 
     Accordingly, when the shaft  36  turns, the sled  27  is moved on the rail  28  with a reciprocating motion that is transmitted by the arm  26  to the carriage  12 . 
     The finger  11  is cut and bent to shape from sheet metal and includes a plane body  31  and a plane beak  32  in a plane perpendicular to the plane body  31 ; the beak  32  and the body  31  have a generally C-shaped configuration so that the body  31  and the beak  32  can be placed on respective opposite sides of the rim  24  of the inclined table  23 ; the body  31  is parallel to the rim  24  and the beak  32  is transverse to the objects  10 . 
     The carriage  12  includes a bore  33  in which is rotatably mounted a shaft  16  fastened to the plane body  31 , in this example perpendicularly to said body  31 , and therefore fastened to the finger  11 . 
     The shaft  16  incorporates a cut-out whose back defines a flat surface  17  parallel to the axis of the shaft  16  (see FIG.  2 ). 
     The shaft  16  is surrounded by a spiral spring  14  one end of which is carried by the plane body  31  of the finger  11  and whose other end is fastened to the carriage  12 ; accordingly, the spiral spring  14  bears against the carriage  12  and urges the finger  11  to rotate in the direction which raises the beak  32 , as explained below. 
     The axis of a cylindrical passage through the carriage  12  is orthogonal to the axis of the bore  33  and tangential to said bore  33 ; a plunger  15  is slidably mounted in said passage; for the plunger  15  to be able to serve as a locking member for immobilising the shaft  16  relative to the carriage  12  in the bore  33 , its diameter is such that it is tangential to the flat surface  17  on the shaft  16 ; to unlock the shaft  16 , the plunger has a groove  18  (see FIG. 2) whose depth is such that when said groove  18  is in line with the flat surface  17 , after the plunger  15  has been moved to bring this about, the shaft  16  is free to rotate inside the bore  33 . 
     As it reciprocates, the carriage  12  moves between two abutments  21  and  22  carried by the chassis  13 , in this example by means of a spacer  25 ; one abutment  21  is the inside face of a plate  42  fixed to the end of the spacer  25  and the other abutment  22  is the inside face of one flange of an L-shaped bracket  42  fixed to the top face of the spacer  25 . 
     In this example the spacer  25  is parallel to the rail  28  and inclined at an angle equal to the angle of inclination of the table  23 , as can be seen in FIGS. 1 and 2. This is not necessarily the case, however. 
     The length of the plunger  15  is greater than that of the passage through the carriage  12  in which it is housed, so that in each extreme position of the carriage  12 , in line with the abutment  21  or  22 , the plunger  15  is adapted to cooperate with each abutment and to be moved one way or the other; when it is cooperating with the abutment  21  (FIG. 4) the plunger  15  is in the position which unlocks the shaft  16 , and the groove  18  is in line with the flat surface  17 , and when it is cooperating with the abutment  22  (FIG. 8) the plunger  15  is in the position which locks the shaft  16 , and the groove  18  is no longer in line with the flat surface  17 . 
     This is how the feeder system according to the invention works. 
     In FIG. 4, the finger  11  is at the end of its operational stroke and the beak  32  of the finger  11  has threaded the hollow cylindrical object  10 A onto the object-carrier mandrel, not shown; the plunger  15  is cooperating with the unlocking abutment  21  and the shaft  16  can be turned in the carriage  12  by the spiral spring  14 ; in this example it is preferred that the finger  11  rest momentarily in this position, a heel-piece  34  of the finger  11  cooperating with a roller  35  at a greater distance from the abutment  21  than the rotation axis of the shaft  16 , and said roller  35  being carried by a support  44  attached to the end plate  41 . 
     During its return stroke (FIG. 5) the finger  11  turns about its axis, progressively freeing the passage for the next object  10 B to take up its position; at about the half-way point of its return stroke (FIG. 6) the heel-piece  34  leaves the roller  35  and the back of the finger  11  abuts against a roller  20  at the end of a boom  43  carried by the L-shaped bracket  42 . 
     Note that in this position the next object  10 B is ready to be threaded onto the object-carrier even though the finger  11 , i.e. the carriage  12 , is only at the half-way point of its travel. 
     As the return movement of the carriage  12  continues, a ramp  19  on the finger  11  cooperates with the roller  20  to return the finger  11  to its operational position against the action of the spring  14  (see FIG.  7 ). 
     The cooperation of the plunger  15  with the locking abutment  22  (FIG. 8) immobilises the shaft  16 , and therefore the finger  11 , in this position, which it retains until it takes up the object  10 B (FIG.  9 ); the operational travel of the carriage  12  continuing, the plunger  15  comes into contact with the abutment  21  (FIG. 10) and then unlocks the shaft  16  while the object  10 B is threaded onto the object-carrier: the situation is therefore that of FIG. 4 again, and a new cycle begins.