Patent ID: 6170797
Filing Date: 2001-01-09
Classification: F15B,F16K

Abstract:
In a rotary actuator of the type wherein two end plates are connected to both ends, respectively, of a cylinder body, and a piston is slidably fitted in a cylinder bore in said cylinder body, and wherein an output shaft is disposed to extend in a direction approximately perpendicular to an axis of said piston, so that a reciprocating motion of said piston is converted into a rotational motion of said output shaft,the improvement wherein said cylinder body is produced from an extruded material formed by extrusion; a section of said extruded material that is perpendicular to a direction of extrusion of said extruded material is circular at an inner periphery thereof and has upwardly, downwardly, leftwardly and rightwardly projecting thick-walled portions at an outer periphery thereof; and outer peripheral portions of said section, exclusive of said projecting thick-walled portions, are generally formed from circular arcs and define with said circular inner periphery generally arcuate wall portions that are thinner than said thick-walled portions.