HOIST DEVICE COMPRISING A LINEAR ACTUATOR WITH A MANUAL LOWERING DEVICE

摘要

This invention relates to a hoist device comprising a linear actuator, said linear actuator (6) comprising an electric motor drive (5), an outer tube (7) and an inner tube (8) that is axially movable in an out of the outer tube (7), said hoist device (1, 13, 12) comprising a lifting arm (1) and a frame structure (12, 13), wherein said lifting arm (1) is pivotally attached to said frame structure (12, 13) and said linear actuator (6) is pivotally attached at one end to said frame structure (12, 13) and at a second end to said lifting arm (1), wherein further a manual lowering device (9) arranged to enable lowering of said lifting arm (1) without use of said motor drive (5), said lowering device (9) being connected between the outer end of the inner tube (8) and an attachment device (10) of said lifting arm (1), said manual lowering device (9) comprising a stationary part (22), a rotatable part (23), a coupling (24) and a manually an operated transmission device (20, 21), wherein said stationary part (22) includes a first threaded member (201D, 319B), preferably in the form of a stub shaft, and said rotatable part (23) is connected to a threaded, clamp activating second threaded member (215, 315), preferably in the form of a nut device, interacting with said first threaded member (201D, 319B), wherein the axial position of said clamp activating second threaded member (215, 315) is arranged to control said coupling (24) to be in engaged or disengaged state and wherein said manually operated transmission device (20, 21) is arranged to control the axial position of said clamp activating second threaded member (215, 315).