A servo-motor pump drive is at the heart of a new series of electric/hydraulic presses said to be quieter, faster, and more precise than standard hydraulic models and more economical than all-electrics.

A servo-motor pump drive is at the heart of a new series of electric/hydraulic presses said to be quieter, faster, and more precise than standard hydraulic models and more economical than all-electrics. The new E-series from Boy Machines Inc., Exton, Pa., is available in two models of 60 and 100 tons. Boy says the variable-speed servo pump motor uses less than half as much energy as a fully hydraulic machine with variable-displacement pumps that run at constant speed. Other features include improved precision: Repeatability measurements showed a max. deviation in part weight of 0.115% from average value. The E-series also emits 20% lower noise than a standard machine. It costs about 5% more than previous Boy hydraulic presses.