| 摘要 |
Variable displacement pistons are produced wherein hollow piston bodies are integrally formed with associated actuator arms to ensure proper alignment o f the bodies and rods. The process utilizes a two-axis press (40) to first for m a pair of actuator arms (14', 14'') by working a blank of metallic material along a first axis (30) between opposing members (42, 44) of a die assembly. With the die assembly still closed after formation of the actuator arms (14' , 14''), a pair of hollow piston bodies (12', 12'') are formed by extruding th e remainder of the blank of metallic material along a second axis (32). The hollow piston bodies (12', 12'') are axially aligned and integrally formed with respective ones of the actuator arms (14', 14''). A piston head is weld ed to the end of each hollow piston body which is then machined. By separating the actuator arms from one another, a pair of variable displacement compress or pistons having hollow piston bodies axially aligned and integrally formed wi th respective actuator arms are thus formed. |
