| 摘要 |
PCT No. PCT/AT87/00002 Sec. 371 Date Nov. 9, 1987 Sec. 102(e) Date Nov. 9, 1987 PCT Filed Jan. 20, 1987 PCT Pub. No. WO87/04483 PCT Pub. Date Jul. 30, 1987.The invention is directed to a penumatic or hydraulic drive for opening and closing of doors, in which the linear motion of a double-acting piston 5 driven by a pressure medium is converted into a rotary motion of a spindle 2 through a piston rod 6 and a helical gear box 3. Herein a blocking lever 10 supported in a stationary manner is provided, which in the closed position of the door engages under the action of a spring 18 at a part 11 connected with a piston 5, wherein said blocking lever secures the piston in its end position and is held in its open position counter to the force of an additional spring 15 by a power cylinder 14 acted upon by the pressure means. |
