| 摘要 |
<p>The lower folders (P1, P2) of the packaging machine are driven by a rod and crank system (1, 2) moved by an electric motor (5) with control of speed and phase, regulated by an electronic processor (7) with a corresponding programming and dialogue unit (8). The rod and crank system is designed and arranged in such a way that, when the folders are closed, the rod (1) is aligned with the crank (2), and this position (K) is taken to be the zero position by the said processor and is detected for this purpose by a sensor (6). To drive the folders through a complete cycle of closing and opening, the motor (5) has to execute only one pulse, to transfer the rod and crank system from one to the other of two limit positions (K1, K2), spaced apart from the said zero position by an identical distance which is variable, according to the format of the products to be packaged, by means of the said programming unit (8). The rod and crank system is also preferably designed in such a way that, when the product has the maximum format, the motor (5) executes intermittent rotations through 360 DEG , always in the same direction, with a cyclical stop in a position opposite to the zero position (K). <IMAGE></p> |
