Sound-dampened driving apparatus for fasteners

A sound and recall-dampened driving apparatus for fasteners, which apparatus includes a housing defining a main working piston cylinder and a cylindrical housing bore thereabove and a main valve means positioned in said cylindrical housing bore above the working piston cylinder and defining a chamber between the valve means and the end of the housing bore, which valve means includes a valve member movable from a lower position, wherein the valve member separates the working piston cylinder from a source of compressed air and connects the cylinder with the atmosphere, to an upper position, wherein the valve member connects the working piston cylinder to the source of compressed air while blocking the connection of the cylinder with the atmosphere, and in which the chamber defined above the main valve member and the end of said cylindrical housing bore is alternately connected to the atmosphere or compressed air, and sound and recoil-dampening means positioned in the chamber above the main valve member, said sound and recoil-dampening means including a delaying disc positioned in and supported for limited axial movement above the main valve member, said delaying disc having a central opening for receiving and guiding an axial flange of the valve member, wherein said delaying disc is formed of a relatively heavy metallic material whereas said valve member is formed of a light synthetic material, a further chamber between said delaying disc and said valve member being alternatively connected to the atmosphere and a source of compressed air, and a resiliently elastic dampening material positioned between said delaying disc and the end of said cylindrical housing bore to bias said delaying disc away from said end of said cylindrical housing bore when said further chamber between said delaying disc and said valve member is connected to compressed air to press said delaying disc against said resiliently elastic dampening material.