| 摘要 |
The device comprises two paddles 1 each one of them being connected to a bar 3, the extremities of which are placed within a cam track. The cam track is formed in the surface turned towards the working zone of support 18 which is located corresponding to both the lateral extremities of the device. The motion of the bars 3 and therefore of the paddles 1 along the cam track 8 which has a rectilinear section 8' and a section of circular sector 8'', is determined for each bar by a pair of connecting rods 7 which has a slit 7. The two ends of the bars 3 close to the extremities are placed in the slit. The four connecting rods 7 rotate synchronously, the rods corresponding to the same paddle being in the same direction, the rods corresponding to the same side of the device being opposite to the other. The device also comprises arms 4 and pin 5 capable of preventing motions of the bars which could be inconsistent with the paddles during the working operation in the phase where they follow a rectilinear motion and are placed in contact one with the other. <IMAGE> |
