A spool may include a drum rotatably supported on an axle shaft and flanges integrally formed with opposite ends of the drum. The drum has a continuous groove on the outer surface of the drum to guide the movement of the safety wireline. Both of the flanges may include an opening, internal threads circumscribing the opening, and a plurality of mechanical brakes. Each of the mechanical brakes may include a rotor rotatably supported on the axle shaft of the spool and a pawl arranged within the opening. The pawl is pivotally linked to the rotor such that when the rotation of the axle shaft is in a direction and at a rotation speed that exceeds a threshold then the pawl is moved by centrifugal force and engages with the internal threads circumscribing the opening and does not permit the spool to rotate.

When a holding unit is lowered, a control unit gradually increases the lowering velocity of the holding unit toward a target lowering velocity, performs a constant velocity lowering operation of maintaining the lowering velocity of the holding unit at the target lowering velocity, and then gradually decreases the lowering velocity of the holding unit from the target lowering velocity to stop the holding unit. The control unit controls the drive unit to gradually increase the rotational velocity of the pulleys in response to a gradual decrease in the diameter of the outer surface of the belt wound-up around the pulley by unwinding in the constant velocity lowering operation.

When a holding unit is lowered, a control unit gradually increases the lowering velocity of the holding unit toward a target lowering velocity, performs a constant velocity lowering operation of maintaining the lowering velocity of the holding unit at the target lowering velocity, and then gradually decreases the lowering velocity of the holding unit from the target lowering velocity to stop the holding unit. The control unit controls the drive unit to gradually increase the rotational velocity of the pulleys in response to a gradual decrease in the diameter of the outer surface of the belt wound-up around the pulley by unwinding in the constant velocity lowering operation.

A cable winch (100) for deploying and retracting a cable (50) during the installation of powerline cables on transmission towers. The cable winch (100) includes a base frame (102), a spool (110), a drive system (120), a sensor system (200), and a control system (300). The spool (110) is mounted for rotation on the base frame (102) and the cable (50) is releasably securable to the spool (110). The drive system (120) is able to drive rotation of the spool (110) to either pay out or wind in the cable (50) along a cable path. The cable path passes through the sensor system (200), which has a first sensor (244) able to detect and output tension data in relation to the tension in the cable (50) passing through the sensor system (200). The control system (300) is adapted to receive the tension data output by the sensor system (200) and modulate the speed and torque of the drive system (120) in order to maintain a predetermined tension in the cable (50).

A cable winch (100) for deploying and retracting a cable (50) during the installation of powerline cables on transmission towers. The cable winch (100) includes a base frame (102), a spool (110), a drive system (120), a sensor system (200), and a control system (300). The spool (110) is mounted for rotation on the base frame (102) and the cable (50) is releasably securable to the spool (110). The drive system (120) is able to drive rotation of the spool (110) to either pay out or wind in the cable (50) along a cable path. The cable path passes through the sensor system (200), which has a first sensor (244) able to detect and output tension data in relation to the tension in the cable (50) passing through the sensor system (200). The control system (300) is adapted to receive the tension data output by the sensor system (200) and modulate the speed and torque of the drive system (120) in order to maintain a predetermined tension in the cable (50).

A cable drive unit (1) for use with a free stall cleaning system (101). The cable drive unit (1) includes a base frame (3), a support frame (5) being displaceable with respect to the base frame (3) via a corresponding displacement assembly (7), and a drum (9) pivotably mountable about the support frame (5) and displaceable therewith for receiving a cable (11) to be wound about said drum (9). Also described is a kit for assembling a cable drive unit (1) and a free stall cleaning system (101). Also described is a method of winding a cable (11) of a free stall cleaning system (101) about a drum (9) via the present cable drive unit (1).

The present invention is directed to a self-locking non-backdrivable gear system. The gear system may comprise a primary motor input and self-lubricating gear box. The primary motor input is for rotation of the gearbox about the axis of a drive shaft. The gearbox may comprise an input ring gear, one or more planet locking gears, fixed spur gear, and output spur gear. In operation, rotation of the primary motor input causes rotation of the ring gear which causes rotation of the planet locking gear which causes rotation of the output spur gear which causes rotation of the drive shaft. However, in the absence of rotation of the ring gear, a rotational force applied to the output spur gear causes the gear teeth on the fixed and output spur gears to lock the planet gear in place.

The present invention is directed to a self-locking non-backdrivable gear system. The gear system may comprise a primary motor input and self-lubricating gear box. The primary motor input is for rotation of the gearbox about the axis of a drive shaft. The gearbox may comprise an input ring gear, one or more planet locking gears, fixed spur gear, and output spur gear. In operation, rotation of the primary motor input causes rotation of the ring gear which causes rotation of the planet locking gear which causes rotation of the output spur gear which causes rotation of the drive shaft. However, in the absence of rotation of the ring gear, a rotational force applied to the output spur gear causes the gear teeth on the fixed and output spur gears to lock the planet gear in place.

This invention relates to a cable drive unit (1) for use with a free stall cleaning system (101). The cable drive unit (1) includes a base frame (3), a support frame (5) being displaceable with respect to the base frame (3) via a corresponding displacement assembly (7), and a drum (9) pivotably mountable about the support frame (5) and displaceable therewith for receiving a cable (11) to be wound about said drum (9). Also described is a kit for assembling a cable drive unit (1) and a free stall cleaning system (101). The invention further includes a method of winding a cable (11) of a free stall cleaning system (101) about a drum (9) via the present cable drive unit (1).

The present invention is directed to a self-locking non-backdrivable gear system. The gear system may comprise a primary motor input and gear box. The primary motor input is for rotation of the gearbox about the axis of a drive shaft. The gearbox may comprise an input ring gear, one or more locking gears, fixed gear, and output gear. In operation, rotation of the primary motor input causes rotation of the ring gear which causes rotation of the locking gear which causes rotation of the output gear which causes rotation of the drive shaft. However, in the absence of rotation of the ring gear, a rotational force applied to the output gear causes the gear teeth on the fixed and output gears to lock the gear in place.