| 摘要 |
<p>Preforms (4) are transferred individually to forms stacks in one or more parallel stacking channels (10) up to a prescribed number. An ejector plate (13) pushes a completed stack (11) forwards towards a channel outlet (17) or a position for stack removal (18). During or following the pushing movement the ejector plate acts as a counter support or stop plate to a newly growing stack (12) behind it. The ejector plate (13) moves into a position in which it faces the first preform of a newly growing stack (12). The ejector plate is held and/or moved with either a degree of play relative to the first preform or contact with the preform end face (23). Forward movement of the plate is at a creeping speed equivalent to the stepped growth of the newest stack and/or with the same speed as the first transferred preform of this stack. A completed stack is moved by the ejector towards the outlet (17) of a stacking channel before a newly growing stack is completed. The latter movement may be at a higher speed or a combination of the creeping speed and a higher speed. Higher speed commences when the newest stack is 33-75%, preferably 50-67%, of its final length. Following ejection of a stack the ejector plate returns to its starting position (A) behind the most recently transferred preform (15). After contact with the latter preform the ejector plate moves forwards over a section at a speed higher than the creeping speed. An independent claim is also included for a stack holder used in the process which has one or more stacking channels (10) for receiving preforms (4) from a punching or forming tool (1) and an ejector plate (13) which can be moved in and out of the stacking channel as well as moving along the channel. A motor drive unit for the plate is linked to a control unit allowing it to be operated at a creeping speed corresponding to the stepped increase in stack growth.</p> |
