ABSTRACT
Hewlett-Packard lifting guidelines and analysis using common ergonomic evaluation tools indicated that manual replacement of heater cores in horizontal furnaces was unacceptable and engineering intervention was required. The design was guided by a number of physical constraints and worker requirements, for example, weight of and access to the heater cores, accessibility to maintenance bays, and the need for elevated work platforms. The cooperative risk reduction effort took a year and involved maintenance technicians, HP’s ergonomics engineer, and engineers from the hoist vendor. The final design employs a strap and roller end-effector with a two-arm articulated manipulator mounted to a counterweighted ball screw type vertical hoist. The hoist has the ability to hold the heater core securely while allowing technicians to place it in position for installation It is also compatible with the requirements of a Class 100 clean room, is powered by an internal power supply with integral charging unit, and has casters which allow for mobility. Using the hoist, the technicians can now perform the replacement procedure without manual lifting of the cores or exceeding standards for lifting and pushing forces. A follow-up survey indicated a high level of satisfaction by the users of the new system.
