Patent ID: 6059049
Filing Date: 2000-05-09
Classification: B25F

Abstract:
An air cylinder apparatus for a pneumatically driven power tool, the power tool having an outer housing and a rotor, which is journalled within the outer housing and which is provided with a fixed front shaft and a fixed rear shaft that are coaxial with each other, said air cylinder apparatus comprising:a unitary outer cylinder member having a front end surface with a bearing accommodating recess, a front bearing plate, and a hollow cylindrical wall, which extends rearward from said front bearing plate and which defines a cylindrical chamber therein, said front bearing plate having a front bearing hole that is formed through a central portion thereof and that is adapted to permit extension of the front shaft of the rotor therethrough, said cylindrical chamber being eccentric from said front bearing hole, said cylindrical wall having an inner surface, which is formed with at least one exhaust port, an axially extending forward guideway, and an axially extending reverse guideway;a cylindrical inner wall member press fitted within said cylindrical wall of said outer cylinder member and having at least one air port that is formed therethrough and that is communicated with said exhaust port in said outer cylinder member, a forward inlet port that is communicated with said forward guideway in said outer cylinder member, a reverse inlet port that is communicated with said reverse guideway in said outer cylinder member, and two spaced adjacent axial sides that define an open-ended axial slot therebetween, so that said inner wall member can be compressed in a radial direction, thereby removing said inner wall member from said outer cylinder member;a rear bearing member mounted removably on a rear end of said cylindrical wall of said outer cylinder member and having a rear end surface with a bearing accommodating recess, a rear bearing hole that is aligned with said front bearing hole in said front bearing plate and that is adapted to permit extension of the rear shaft of the rotor therethrough, a forward passageway and a reverse passageway that guide air into said inner wall member; andtwo bearings disposed respectively within said bearing accommodating recesses in said outer cylinder member and said rear bearing member and adapted to journal the front and rear shafts of the rotor thereon.