The Body and Scotch-Yoke

The body configuration is computer designed to optimize the transmission of force through the piston rod to the torque plug. Sturdy bearing surfaces assure effective sealing and long life through efficient torque transmission. A thrust pin is secured to the piston rod, and a roller is placed over the pin to allow free movement within the slot of the torque plug. This acts to reduce friction and wear. The torque plug has a closed cast slot; it is not open on one end. As a result, there will be no lost motion due to springing open under high torques. Obviously, to obtain maximum efficiency, all tolerances are closely held.

More than economy, efficiency means dependability. For example, the journals of the torque plug provide wide bearing surfaces for ease of rotation. These also resist side thrust and wear caused by possible misalignment in mounting to a valve or damper. The piston rod slides through bronze bearings secured between the body and the cylinder adapter or rod cover. The bearing is designed to minimize friction, but the area is sufficient to counter side thrust and wear.