Patent ID: 7175403

Claim:
A rotary actuator comprising; an actuator housing; a rotor having an axis of rotation mounted in the housing and including at least one rotor vane rotatable with the rotor, the rotor vane having a first edge parallel to the axis of rotation and a second edge extending from the first edge, the rotor including a vane opening in said first edge into a first vane channel in said at least one vane; an endplate in the housing adjacent said rotor vane second edge; a vane seal on said rotor vane first edge over the vane opening and engaging said actuator housing, said at least one rotor vane and said vane seal dividing said actuator housing into a first chamber and a second chamber; a corner seal mounted in a corner seal recess in said endplate, said corner seal being shiftable between a first position contacting said rotor vane second edge to form a seal between said first chamber and said second chamber and a second position allowing fluid communication between said first chamber and said second chamber; and a second vane channel in fluid communication with said first vane channel and said corner seal recess; said vane seal being mounted to expose said vane opening to pressure in said first chamber when the pressure in said first chamber is greater than the pressure in said second chamber and to expose said vane opening to the pressure in the second chamber when the pressure in the second chamber is greater than the pressure in the first chamber; whereby, the higher pressure of the pressures in the first chamber and the second chamber is applied against the corner seal via the first vane channel, the second vane channel and the corner seal recess to maintain said corner seal in said first position.