Valve and handle for an air operated tool, and method of fluid control

Claim 1

A fluid operated tool comprising a one-piece pistol grip handle and cylinder cap, a trigger on said handle, said cylinder cap having an open front end, a cylinder detachably secured within said cylinder cap and having a piston slidable therein, said cylinder having a reduced outer diameter rearward end forming an annular port surrounding said rearward cylinder end, said cylinder having its terminal inner edge in abuting engagement with said cylinder cap and being provided with notch means communicating said annular port and said cylinder, a pressurized fluid inlet in said handle, passage means in said handle connecting said inlet and said annular port, a ball check valve in said passage means normally preventing flow of pressurized fluid to said annular port, valve means operable by said trigger to open said check valve, said valve means including a tapered projection extending into a cylindrical bore forming a part of said passage means, said cylindrical bore communicating with the atmosphere, whereby initial movement of said trigger unseats said ball check valve and communicates an inlet in said annular port, and continued movement of said trigger past said initial movement brings the larger part of said tapered projection into said cylindrical bore and progressively restricts communication of said cylindrical bore with the atmosphere.