GB1148995A - Cable Winch Assembly - Google Patents

Abstract

1,148,995. Constant tension winches. THEODORE J. KOENIG. 19 Jan., 1968 [25 Oct., 1967], No. 3109/68. Heading B8B. The drive for the drum shaft 45 of a constant tension winch comprises an electric motor shaft carrying a sun gear, a carrier freely rotatable on the shaft and carrying planet gears engageable with the sun gear and an internal ring gear, and a reduction gear drive 42, 44 (part only shown between the carrier and the shaft 45, the ring gear and motor shaft which are clutchable to each other being each provided with a brake. The clutch and ring gear brake are jointly electrically operable to give either a low speed or a straight through drive to the reduction gear 42, 44, the low speed drive being normally in operation. A winching drum 52 is freely rotatably mounted on the drum shaft 45 and is drivably connected therewith through a compression spring 60 connecting an ear 58 on one flange 55 of the drum with an ear 57 on a flanged hub 50 keyed to the drum shaft 45. With this arrangement, the compression of the spring 60, i.e. the relative rotation between the drum 52 and the shaft 45, is a measure of the tension T in a cable 62 wound on the drum. This relative rotation is translated into axial movement of a sleeve 68 freely mounted on the shaft 45 and having a projection 70 which is connected via pivoted links 72, 74 to the drum at 78 and to a projection 66 keyed to the shaft 45. The axial movement of the sleeve 68 is transmitted through a linkage system to control the electric drive motor whereby a substantially constant tension in the cable 62 is automatically maintained. If after a fixed time the cable tension has not reached a pre-determined value, the drive motor torque is increased automatically at intervals until either the tension is reached or the motor cuts out and the brakes are applied to lock the system. If during cable pay-out, the motor voltage is increased to a pre-determined level due to rapid over-riding of the system by the cable, a voltage sensing relay operates to energize the ring gear brake and clutch, producing the straight-through drive to the motor whereby its speed is reduced.