| 摘要 |
PCT No. PCT/SE87/00433 Sec. 371 Date May 22, 1989 Sec. 102(e) Date May 22, 1989 PCT Filed Sep. 25, 1987 PCT Pub. No. WO88/02478 PCT Pub. Date Apr. 7, 1988.Method and device for indicating overload are provided for a load suspended from a hoist. The hoist comprises a slip-ring induction motor (1). The input power together with the angular acceleration of the motor are metered. Then the metered values are compiled in a computer (5) by means of a suggested formula in order to estimate the hook load. The lift will be stopped, if the hook load continuously exceeds a predetermined value during a predetermined time. |
