| 摘要 |
PCT No. PCT/EP91/02506 Sec. 371 Date Jun. 28, 1993 Sec. 102(e) Date Jun. 28, 1993 PCT Filed Dec. 23, 1991 PCT Pub. No. WO92/12362 PCT Pub. Date Jul. 23, 1992.A two-speed linear actuator with high thrust and a high speed of translation for a machine, particularly a bending press. A linear actuator for a machine, particularly a bending press, having first and second bodies (2, 4) mounted for sliding relative to each other and a male-and-female screw mechanism (14) for controlling a relative sliding movement of the two bodies along a working line. The male screw (16) and the female screw (27) are supported for rotation by the first and second bodies (2, 4) and can be rotated by respective electric motors (24, 38). The motors (24, 38) are associated with respective speed-reduction devices (22, 26 and respectively 36) having substantially different reduction ratios. The actuator further includes a braking device (42, 44) associated with the member of the male-and-female screw mechanism (14) which is connected to the speed reduction device (22, 26) with the lower reduction ratio. |
