Patent ID: 7007447
Filing Date: 2006-03-07
Classification: A01B,A01D,F15B

Abstract:
1. A self-contained actuator device adapted to move an object, the actuator device comprising: a housing containing a substantially fixed mass of air sufficient to operate the actuator device, the housing substantially sealed such that the substantially fixed mass of air is maintained therein; a movable piston positioned in the housing and separating the housing into a first chamber and a second chamber, the piston being movable along a longitudinal axis in response to changes in air pressure in the first and second chambers; a rod coupled to the piston for movement with the piston, the rod extending through the first chamber and at least partially extending outside of the housing to couple to the object; and an air transfer device positioned in the second chamber of the housing, the air transfer device selectively energized based upon air pressure in the first chamber to transfer air from the second chamber of the housing to the first chamber of the housing, thereby moving the piston and the rod in a retracting directions, wherein to move the piston and the rod in an extending direction, air is vented from the first chamber to the second chamber.