Sleeve for a pneumatic fastener-driving tool

摘要

A fastener driving tool (10) including a housing (12) enclosing a cylinder (18) having a lower end provided with a resilient bumper (72), a return air chamber (60) in communication with the lower end of the cylinder (18) and a piston (26) dimensioned for reciprocation within the cylinder (18) to impact the bumper (72) at an end of the cylinder (18) and having a driver blade (28) depending therefrom for striking fasteners. At least one inlet opening (62) is disposed in the cylinder (18) and in communication with the return air chamber (60) and at least one outlet opening (64) is disposed in the cylinder (18) and spaced from the at least one inlet opening (62). The at least outlet opening (64) is in communication with the return air chamber (60) and aligned with the piston (26) so that each outlet opening (64) is closed by the piston (26) to seal the cylinder (18) from air loss as the piston (26) impacts the bumper (72) and traps a residual volume of air in the sealed cylinder (18) below the piston (26) to damp impact of the piston (26) upon the bumper (72).