Portable pneumatic percussive tool

Abstract

A tool comprises a body, a hammer accommodated in the body, a working implement removably received in the front end portion of the body, a differential spring having one end connected to the front end part of the body, and the other end of a tapered shape resting with its inner surface against the tapered outer surface of a sleeve, which embraces the working implement, in the direction of the rear end of the body so as to urge the sleeve with its rear end face against the front end face of the body and with the inner surface against the outer surface of the working implement, whereby the sleeve together with the spring form a resilient coupling between the body and the working implement, said coupling allowing the working implement to move forward at the instant of blow, with the working implement being jammed in the material being demolished, due to the expansion of the spring, while after the delivery of a blow said coupling causing the body to move forward under the action of the spring being contracted, whereby vibration of the body in the direction toward the operator is lowered and the thrust force to be exerted upon the handle is reduced. The invention is aimed at lowering vibration of the tool body.