摘要 |
1. Work piece loader or extractor including a mobile carriage (5) movable horizontally along a fixed frame (1), a vertically movable slide (17) mounted on the carriage (5) and carrying a support (28) with gripping means (29a-29b) adapted for gripping a metal sheet or a work piece, a first motor (16) associated with drive means for moving the carraige horizontally and a second motor (27) for moving the slide vertically, these two motors being fixedly mounted on the frame (1) and the output shaft of the second motor (27) being connected to a horizontal splined shaft (22) mounted for rotation on and along the frame and on which is slidably keyed a pinion (21) immobilized laterally with respect to the slide (17), characterized in that said pinion (21) is engaged with a vertical rack (21) fixed to the slide (17), in that said loader includes means (32-33-34-35) for counterbalancing the torque exerted on this splined shaft (22) by the weight of the slide (17) and of the support 28) equipped with gripping means (29) and in that these counterbalancing means include an actuating cylinder (33) controlling a counterbalance rack (32) which is engaged with a pinion fixed on the splined shaft (22), means (34-35) preventing said rack (32) from being rotated by the splined shaft (22). |