Patent ID: 8087316

Claim:
A Scotch yoke actuator comprising: a dual yoke having a center and first and second yoke ends, the first and second ends being symmetrical about the center, said first yoke end having a first yoke slot, said second yoke end having a second yoke slot; a rotatable shaft attachment point at the center of said dual yoke whereby the dual yoke can be attached to a rotatable shaft oriented perpendicular to a plane that contains said yoke slots; first and second pushing shafts, said first pushing shaft being coupled to said first end of said dual yoke, said second pushing shaft being coupled to said second end of said dual yoke, wherein each pushing shaft extends from the dual yoke in substantially one direction, the first and second pushing shafts extending from the dual yoke in opposite directions; and a pair of pushing devices disposed on diametrically opposite sides of said rotatable shaft attachment point and operatively connected to said first and second pushing shafts, respectively, said first pushing shaft being movable in a first direction along a first axis by said first pushing device, said second pushing shaft being movable in a second, opposite direction along a second axis by said second pushing device, said first and second axes being substantially parallel to one another and on diametrically opposite sides of said rotatable shaft attachment point, said first pushing device pushing said first pushing shaft in said first direction substantially simultaneously with said second pushing device pushing said second pushing shaft in said second direction, whereby end loading forces applied to a rotatable shaft connected to said rotatable shaft attachment point are cancelled and eliminated.