SYRACUSE, NY — J. R. Clancy has developed a new braking system for its PowerLift hoist system. “Our engineering department has developed an even faster acting load brake, to catch any failure before it becomes a runaway,” said Mike Murphy, president. PowerLifts have a dual braking system — the primary brake is on the motor, and stops the motor at the end of a move. The load brake is a redundant brake acting on the drum shaft for added safety. Since it’s on the output side of the gearbox, it’s a much heavier (and more expensive) brake than the primary brake.
“The current load brake is a Weston brake,” said J. R. Clancy engineer Pete Svitavsky. “It has some great features such as self adjustment and purely mechanical ‘self energizing’ actuation. However, due to the amount of energy it absorbs whenever the machine moves downward, there is a practical limit to the size and speed of the load it can control.”
The new electric brake is spring-applied and electrically released, acting on the drum shaft. In contrast to the Weston brake, which is applied each time the load is lowered, the new brake is not applied during normal operation, reducing wear and noise.
Speed sensors on the motor and drum shaft let the system compare the actual speed with both the commanded speed and maximum speed. The sensors can also monitor the integrity of the shafting and gearbox for an added level of security. These sensors can detect problems at the moment they occur and respond quickly. This minimizes the stopping distance as well as the forces on the rigging and the payload.
PowerLifts with SureBrake II will begin shipping in the late summer.
For more information, please visit www.jrclancy.com.
