Abstract:
A manipulator for transporting work pieces, especially between two subsequent molding presses of a press working line, including a moving mechanism allowing three dimensional movements on the path between the molding presses, a supplemental arm attached to the moving mechanism and connected to this moving mechanism via a support member that allows a swiveling movement of the supplemental arm around a vertical axis of the support member as well as a translation movement of the supplemental arm with respect to the support member, and a tool support provided at the outer end of a supplemental arm, the tool support being rotatable around a horizontal first axis and around a second axis perpendicular to the first axis, the tool support including a tool reception that is rotatable around a third axis perpendicular with respect to the second axis.

Description:
BACKGROUND OF THE INVENTION 
     The present invention refers to a manipulator for transferring work pieces, especially between two subsequent molding presses within a molding press line, comprising a moving mechanism for performing three dimensional movements on the path between the two molding presses. 
     Manipulators are known in a large variety. Some of these manipulators comprise a pivotable manipulator arm with at least two limbs that are connected pivotable around a horizontal axis. By this pivoting or folding movement, the distance from the outer end of the manipulator arm to its support can be shortened or prolonged. Moreover, the height of the outer end of the manipulator arm can be changed by suitable pivoting movements of the two limbs of the arm around their horizontal pivot axis. 
     When work pieces between two molding presses are transferred, it must be considered that there is not much space between the molding presses, and the space between the upper press tool and the lower press tool of one press is very shallow. For this reason this is a common problem to transfer relatively large work pieces from one molding press into another. If manipulators of the above kind are used for this purpose, comprising foldable arms, the support basis of the adjacent molding presses as well as the support of the manipulator itself obstruct the movement, because the manipulator arm follows a circular arc path during the pivoting movement with its outer end and approaches the basis of the molding presses. 
     Moreover, another problem is related to the construction of such manipulators, because their movement during the transfer of the work pieces is relatively time consuming and takes much energy. 
     Apart from the above mentioned manipulators comprising a pivoting arm, there are also so-called linear robots with a relatively simple construction that perform a relatively simple linear transfer movement between the molding presses. However, the known linear robots only comprise very few degrees of freedom in the movement of the work pieces, and so they are not suited for the use in a molding press line. Pivot arm manipulators as well as linear robots both have the common problem that the tool support at the end of the manipulator arm has a construction height that makes the insertion of work pieces in a relatively shallow space within the molding press very difficult. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a manipulator of the above kind that allows a movement of the work piece with many degrees of freedom and low expense of time and energy. In particular the transfer of a work piece in the small space between the molding presses and an insertion of an end of manipulator arm in the shallow space between the press tools shall be possible. 
     According to the present invention, this object is achieved by a manipulator comprising the features of the claims. 
     According to the present invention, a supplemental arm is attached to the moving mechanism via a support member that allows a pivoting movement of the supplemental arm around the vertical axis of the support member as well as a linear transfer movement of the supplemental arm with respect to the support member. This turning ability in connection with the option to extend the supplemental arm with respect to the original manipulator arm provides a high flexibility. In particular the distance between the tool support and the support basis of the manipulator can be shortened or prolonged by the linear extraction and contraction movement, without folding the manipulator arm or moving it in another way of operation. 
     At the end of the supplemental arm, a tool support is provided that can be pivoted around a horizontal first axis and around a second axis that stands particular with respect to the first axis. Therefore the tool support can be moved freely in space to provide a relatively free position of the workpiece that is supported by the tool. The tool reception of the tool support is additionally turnable around the third axis that stands perpendicular to the second axis. By this there are additional degrees of freedom for the tool at the tool support. 
     In particular it is possible to pivot the second axis of the tool support by turning it around the horizontal first axis into a horizontal position and to position the tool reception by turning around the second axis also into the horizontal plane, with the result that all three axis are in the same horizontal plane. In this position the end of the supplemental arm with the tool support and the tool reception has all together a relatively low height and allows an insertion of the workpiece into a relatively shallow press space. This introduction can be performed mainly by a linear extraction of the supplemental arm at its support member. 
     Because the construction according to the present invention provided advantages with respect to its building height in taking and inserting the workpiece in and out of the moulding press, the workpiece can be turned and pivoted freely in the space between the two molding presses because of the large number of degrees of freedom, additional to a linear movability performed by a supplemental arm towards the manipulator support basis or away from it. The respective movements can be performed with relatively low effort of time and energy. 
     Preferably the tool support is received within a rotation support for rotating around the second axis, while the rotation support itself is held at the end of the supplemental arm rotatable around the first axis. 
     The tool reception is provided preferably as a bar-shaped holder, with the bar axis representing a third axis. 
     According to a preferred embodiment of the present invention, the end of the supplemental arm comprises an articulated joint member that is pivotable around a vertical axis and its end supporting the third axis. 
     With this articulated joint member, the tool support can also be held pivotable at the end of the supplemental arm in a position for moving into the press space, in which the first, second and third axis lie in a common horizontal plane. This pivoting within the horizontal plane around the axis of the articulated joint member can provide a small angular inclination of the supplemental arm with respect to the introduction direction. 
     Preferably the articulated joint member is fork-shaped and receives the rotation support from both sides. 
     According to another preferred embodiment of the present invention, the moving mechanism comprises a horizontal beam at which the support member is supported movably along the length of the beam and movable in a vertical direction. 
     The beam is provided for bridging a longer path within the space between the adjacent molding presses. Between the ends of the horizontal beam, the support member for the supplemental arm is moved, and it can perform the above described movements for introducing and taking workpieces in its respective end positions. 
     According to another preferred embodiment, the manipulator comprises a foldable arm with a plurality of limbs, while the supplemental arm is provided at the end of this foldable arm. 
     By the supplemental arm, the above described disadvantages of a foldable manipulator arm are compensated at least partially, because the provision of the flat supplemental arm decreases the danger of collision of the folded parts of the manipulator arm with the support basis of the molding press. 
     Preferably one or more motors are provided for performing the rotation around the first axis, the second axis and/or around the third axis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following a preferred embodiment of the present invention is described with respect to the following accompanying figures. 
         FIG. 1 to 3  show a preferred embodiment of a manipulator according to the present invention within a molding press line; 
         FIG. 4  is a perspective detailed view of the manipulator from the  FIG. 1 to 3 ; 
         FIGS. 5A and 5B  are side views of the shown embodiment of the manipulator according to the present invention into different positions of the tool support; and 
         FIGS. 6 and 7  are a side view and one perspective view of the manipulator according to the present invention in another position of the tool support. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows two subsequent molding presses  10 , 12  within a molding press line in a schematic manner. Between the molding presses, a manipulator  14  according to the present invention is provided for transferring a workpiece  16  from a first press  10  into the subsequent second press  12 . Press  10  comprises a taking position  18  on top of the lower half  20  of a press tool  22 , while the second press  12  comprises a reception position  24  on top of the lower half  26  of its press tool  28 . The manipulator  14  is provided for taking the workpiece  16  after the pressing operation within the first press  10  from the taking position  18  and to transfer it into the reception position  24  of the second press  12 . 
     For this purpose the manipulator  14  comprises a horizontal beam  30  extending within the space between the two presses  10 , 12 . At the beam  30 , rails  32  are provided onto which a horizontal carriage  34  is movable between both ends of the beam  30 . At the horizontal carriage  34 , a vertically movable vertical carriage  36  is provided that comprises a support member  38  at its lower end. This support member  38  supports a supplemental arm  40  that can be shifted with respect to the support member  38  in the longitudinal direction of the supplemental arm  40  and can be pivoted around the vertical axis of the support member  38 . 
     At the end of the supplemental arm  40  a tool support  42  is provided in a way that is described in the following, said tool support  42  being tiltable and turnable around different axes. The tool support  42  supports a tool  44  for transporting the work piece  16 . Because of the moving mechanism formed by the horizontal beam  30 , the horizontal carriage  34  and the vertical carriage  36 , the tool support  42  can practically reach each any desired point within the space between the presses  10 , 12  between the taking position  18  and the reception position  24 . 
     While  FIG. 1  shows an intermediate position in which the supplemental arm  40  stands vertically with respect to the beam  30 ,  FIG. 2  shows an extremely extracted position of the supplemental arm  40  in which the workpiece  16  is taken from the first molding press  10 , while  FIG. 3  shows a position between the position of  FIG. 2  and position of  FIG. 1 , in which the supplemental arm  40  is partially contracted towards the support member  38  but still oriented in the longitudinal direction parallel to the beam  30 , before it is pivoted into the position of  FIG. 1 . In the following movement for inserting the workpiece  16  into the subsequent molding press  12 , the supplemental arm  40  is pivoted further in the same turning direction with respect to the support member  38  so that the reception position  24  for the workpiece  16  is reached. 
     It can be taken from  FIG. 2  that the tool support  42  at the end of the supplemental arm  40  within the press room of the first molding press  10  between the two halves of the press tool  22  takes a different position from that shown in  FIGS. 1 and 3 . This change of position of the tool support is possible due to a construction that will be described in more detail in connection with  FIG. 4 . 
       FIG. 4  shows an extracted portion of the supplemental arm  40  that is held at the end of the support member  38 . The end  46  of the supplemental arm  40  carries an articulated joint member  48  that is fork-shaped and that is pivotable with respect to the fixed end  46  of the supplemental arm  40  around a vertical axis A 0 . The pivoting space of the articulated joint member  48  is delimited in a lateral direction by lateral stoppers  50 , 52  formed by the vertical side walls of the hollow profile that form the supplemental arm  40 . For pivoting the articulated joint member  48 , a motor drive is provided that is not further explained here. 
     The fork-shaped articulated joint member  48  comprises two parallel flat bracket arms  54 , 56 . Between these bracket arms  54 , 56  a rotation support  58  for rotatably supporting the tool support  42  is received. The rotation support  58  itself is held pivotable between the bracket arms  54 , 56  of the articulated joint member  48  and can be turned around a horizontal axis A 1  that stands perpendicular with respect to the rotation axis A 2  of the tool support  42 . This rotation axis A 1  of the rotation support  58  shall be designated as first axis A 1  in the following, while the rotation axis A 2  of the tool support  42  will be designated as second axis. The turning of the rotation support  58  between the bracket arms  54 , 56  is performed by means of motor drives  62 , 64  that are provided at the outer sides of the bracket arms  54 , 56 . For turning the tool support  42  another motor drive  66  is provided on the second axis A 2  between the bracket arms  54 , 56 . 
     The tool support  42  comprises a pin  68  that is received with one of its ends within a rotation support  58 . Rod-shaped tool receptions  70 , 72  extend from the remaining free end of the pin  68 , and their rod axis lie on a common third axis A 3  that stands perpendicular to the second axis A 2 . The tool receptions  70 , 72  are turnable around the third axis A 3  at the pin  68 . The turning is performed by a corresponding rotation drive  74 , 76  for turning the respective tool reception  70 , 72  with respect to the pin  68 . Each tool reception  70 , 72  carries one portion of a tool for lifting the workpiece  16 . 
     While the tool support  42  can be turned around the first axis A 1  and around the second axis A 2 , so that the rod-shaped tool receptions  70 , 72  can take the desired position in space, the workpiece  16  can be positioned by rotating the tool receptions  70 , 72  around the third axis A 3 . This provides a great number of degrees of freedom in the movement of the workpiece  16 . Moreover, the tool support  42  can take the flat position shown in  FIG. 4 , in which all three axes A 1 , A 2  and A 3  lie within a common horizontal plane, and the rod-shaped tool receptions  70 , 72  are positioned by turning around the third axis A 3  so that the workpiece itself takes a horizontal position. In this position the workpiece  16  can also be introduced into a space between the two pressing tools of a molding press  10 , 12  that is relatively shallow. 
     From this position the tool support  42  can be moved into a position as shown, for example, in  FIG. 5B .  FIGS. 5A and 5B  represent lateral views of the present embodiment of a manipulator according to the present invention into different positions of the tool support  42 , namely the position according to  FIG. 5A , which has already been described with respect to  FIG. 2 , and the position according to  FIG. 5B , corresponding to  FIGS. 1 and 3 . 
     When the tool support  42  is turned around the first axis A 1  from the position of  FIG. 5A , in which the second axis A 2  lies horizontally, with the result that a second axis A 2  stands vertical, the position of  FIG. 5B  is reached. It is clearly shown that in the position of  FIG. 5B  the tool support  42  has a much greater construction height than in the preceding according to  FIG. 5A . Therefore the flat position of  FIG. 5A  is preferred to introduce a workpiece  16  into a molding press  10 , 12  or to take it from the press. During the transfer from the position of  FIG. 5A  into the position of  FIG. 5B , the horizontal orientation of the workpiece  16  can be maintained due to the turnability of the rod-shaped tool receptions  70 , 72  around the third axis A 3 , compensating the rotation around the first axis A 1 . The third axis A 3  as the rod axis of the tool receptions  70 , 72  is then pivoted around the horizontal first axis A 1 , while both axes are held parallel. 
     The inventive axis construction of the tool support  42  also provides other applications.  FIG. 6  shows a situation in which the second axis A 2  lies in the horizontal plane and the tool receptions  70 , 72  are turned around their rod axes, mainly around third axis A 3  in a way that the workpiece  16  takes a vertical position. Such a position can be useful in cases in which the workpiece  16  must be taken from a vertical position and must also be deposited in a vertical position. During the transfer from one position into the other, the workpiece  16  can take any desired position, depending on the space between the two molding press stations. 
     The situation of  FIG. 6  is also shown in a perspective manner in  FIG. 7 . It can be seen that the rod-shaped tool receptions  70 , 72  are turned with respect to the position of  FIG. 4  around 90° around the pin  68  so that the vertical position of the workpiece  16  is reached.