1. Technical Field
This invention relates to an apparatus and method for inverting and transferring parts between two workstations and, more particularly, for inverting the parts as well as transferring them.
2. Discussion
Transfer machines are used to automatically transfer parts between two workstations. These workstations can, for example, be two metal stamping presses which perform sequential operations on a workpiece. In some instances it is preferable for one of the presses to operate on an opposite side of the workpiece. Thus, it becomes necessary to turnover or invert the workpiece 180.degree. about a horizontal axis.
Various attempts to accomplish this function have been made. U.S. Pat. No. 3,921,822 to Dickson generally discloses a machine having jaws which pick up a part at a loading station and place the part at a delivery station. The machine may be adapted to turn the part over, end over end, during its transfer between the stations. In U.S. Pat. No. 2,904,192 to Reynolds et al a transfer device is disclosed for light bulbs that inverts the bulb during its travel. U.S. Pat. No. 3,941,240 discloses grippers which engage and invert the workpiece. U.S. Pat. No. 4,493,450 to Yuzui likewise discloses machinery that inverts the part. The patent to Wenzel (U.S. Pat. No. 730,424) generally discloses a rack and gear arrangement for inverting bottles.
U.S. Pat. No. 3,342,125 to Curran generally discloses apparatus for reversing a workpiece in an automated press line. Some of the disadvantages of the approach taken in this patent are that the turnover equipment is connected to the presses in such a manner that it cannot be easily removed to obtain access to the presses for die changeover purposes and the like. In addition, this prior approach is not easily modified to accommodate different parts nor is it easily moveable to different locations within the production plant.