Abstract: A tool assembly of the automatic hammering or roto-hammering type and a handle assembly therefor. The tool assembly includes a breaking tool having a longitudinal axis. The handle assembly includes a head fixedly interconnected with the tool and two handles pivotally interconnected with the head. The handles include elongated crossed levers and are each provided with biasing members biasing the handles towards the head.

Abstract: The invention concerns an anti-freezing device for pneumatic tools to avoid the immobilization of the striker piston because of freezing up. A thermally insulating sleeve, broken only at the level of the air exhaust apertures of the cylinder, separates the body of the hammer from an annular chamber into which the apertures open. An exhaust passage connects the annular chamber with the exterior and extends along the external wall of the exhaust silencer parallel to the striker piston. The exhaust silencer also is provided, above and below the annular chamber with two hermetically sealed chambers, which prevent the cooling of the naturally hot zones of the hammer by the air in the exhaust passage.

Abstract: A compressed air distribution system to control the movement of a reciprocating concrete breaking jackhammer wherein a plastic distributor made of two individual pieces is provided with a seat on each piece for a pellet moving therebetween is disclosed. The efficiency of the distributor is significantly increased as a result of the reduction of shock loading on the seats as well as the virtual elimination of vibration as a result of rebounding of the pellet. These improvements significantly increase machine performance and lowers the manufacturing cost.

Abstract: A reciprocating piston jack-hammer is provided with an easily detachable air distribution mechanism, a resilient casing for muffling the noise by the emitted air, and a shock absorbing housing. A cylindrical tube houses the reciprocating piston and has molded thereabout a housing with air channels between the housing and the tube. The handle of the jack-hammer has a cavity and a mechanism which controls the supply of compressed air to the distribution system. The distribution system employs two parts, one disposed in the other, with an oscillating pellet between the two parts, which oscillating pellet serves to distribute the incoming compressed air either to drive the piston or to direct the air to a piston relief channel, thereby returning the piston to the upper position. Upon return of the piston to its upper position, the air is exhausted from the cylinder below the piston out to a muffling exhaust chamber, out to the atmosphere.

Abstract: The invention is a rotary drive system for a jack hammer which incorporates a plurality of annular sleeves to transfer the motion generated by the piston to the tool holder and thereby allows the piston to strike the tool when the piston moves in the forward direction. Upon the return stroke of the piston, the annular sleeves are provided with mutually engaging helical splined teeth which causes a partial rotation of the tool holder and thereby provides rotation of the tool holder prior to the piston's next impact with the tool. All of the components are annular and, therefore, easily assembled into the bore of the jack hammer housing. Also, the use of helical splines significantly reduces the frictional resistance of the complete system.

Abstract: The invention is a unique air inlet control system for a distributor of a jack-hammer wherein the inlet control valve is mounted in the inlet passage so as to be pivotally movable by a sliding rod which is in intimate contact with the control trigger mounted in the handle as well as the valve body. The arrangement permits any force that is applied to the control trigger to be translocated to the valve body and thereby unseat the valve body. Further, when the force is removed from the control trigger, the compressed air acts on the sliding rod to allow the valve body to return to a sealed position.

Abstract: The invention permits the interchangeability of a variety of shifters on the same housing of a jack hammer. The one piece housing is provided with two appropriately placed lugs with coaxial holes which intersect with the central bore of the housing. By utilizing an appropriate sleeve, this housing can be used regardless of whether a spring pin type or a latch type shifter is used. With a spring pin shifter, the coaxial holes are used to lock the shifter in place and thereby contain the tool within the sleeve. With a latch type shifter, a groove in the sleeve is aligned with the coaxial holes permitting the insertion of a pin to hold the sleeve in the housing. Flanges on the sleeve provide the appropriate mounting means for the latch.