Abstract: An apparatus for generating impacts which has a hydraulic cylinder and a reciprocating piston. The hydraulic cylinder has an impact chamber, a cavity which receives and diverts fluid, and a throat which connects the impact chamber with the cavity. When the pressure line is connected to the cavity, the piston is lifted to an upper position. When the overflow line is connected to the cavity, the piston drops down such that the piston enters and covers the throat at the impact chamber. The pressure in the chamber remains low as the chamber is sealed by the piston entering the throat, where the energy loss is insignificant. The piston enters into the throat such that it is stopped and presses against the fluid inside the impact chamber, and thereby generates an impact therein. The piston is lifted up to repeat the cycle, when the cavity is connected to the pressure line.

Abstract: A tool for driving a nail or other fastener is actuated by a caseless propellant charge formed of combustible material that is transported into a combustion chamber on a strip. The propellant charge is ignited by striking a sensitizer portion of the charge at an oblique angle. The ignition member intermixes the sensitizer material with an oxidizer layer of the surface of the propellant charge, resulting in combustion of the charge. When ignited, the propellant charge is compressingly interposed between an orifice plate and a movable portion of the combustion chamber. The orifice plate includes a pedestal with an annular compression surface that separates the surface of the ignition area from the remaining surfaces of the charge, insuring that ignition gases are forced through the charge. An annular C-shaped ring is interposed between the orifice plate and the movable portion of the combustion chamber.

Abstract: An explosive powder charge operated setting tool contains a channel (7) located between an inner piston guide (2) for a piston (1) and an outer housing part (6). At the rear end of the tool, the channel (7) continues in a carrier (3) and can be in communication with a cartridge receptacle (4) in the carrier (3). In its front region, the channel (7) is connected via a first opening (2c) in the piston guide (2) with a guide bore (2a) for the piston (1). Towards the rear end of the channel (7) there is a valve arrangement for forming a propellant gas storage space connected through the first opening (2c) to the guide bore (2a). Propellant gases within the storage space are compressed by the piston (1) driven in the setting direction and, after completion of the driving or setting procedure, serve to return the piston (1) back into its rear starting position by expansion of the storage space gases.

Abstract: A pneumatic tool includes: a main cylinder having an operating lever for on-off control for the supply of compressed air into the pneumatic tool, a barrel member resiliently coupled to the main cylinder and having a tool unit secured at its front end portion, and an automatically closed throttle valve held in the main cylinder, whereby upon touching on a working object when starting the pounding job, the barrel member will be retracted to open the throttle valve for performing the pneumatic operation by the pneumatic tool; and when subjected to no load condition, the throttle valve will be restored and closed automatically to temporarily stop the pounding of the pneumatic tool to minimize vibration hazard, and an air cushion is inherently formed between the barrel member and the main cylinder for dampening or absorbing the vibration shock of the pneumatic tool.

Abstract: The impact hammer comprises a working piston (22) which is displaceable within a working cylinder (21) and controlled by a control means (40,41) in such a manner that it exerts impacts onto an anvil surface (23) of an adapter (24) which can be connected to the object to be advanced. When retracting the object, a return impact piston (51) exerts impacts onto the adapter (24) in opposite direction. Thereby, it is achieved that the object can be better released from the drill hole.

Abstract: Rock drilling device for drilling with a drill string comprising a set of tubes (1) and a set of rods (2) arranged centrally in the set of tubes.

Abstract: A fastener driving tool prevents the tool from twice striking, so-called double-driving in a single driving operation. A portion closing the lower end of a cylinder of the tool is formed with an annular recess to receive a ring bumper as a shock absorber of a piston. The recess has a sufficient depth to move a lower portion of the bumper downward and upward. The bumper is fittingly pressed into the recess to form an air chamber in the recess closed by the lower end of the bumper. A check valve is positioned between the air chamber and a supply of the pressurized air to feed the pressurized air to the air chamber so that the pressurized air is further compressed by the bumper which is downwardly moved by the abrupt downward movement of the piston. Thus, greater reaction force is applied from the air chamber to the lower portion of the bumper so as to prevent a driver of the tool from the double-driving.

Abstract: A battering ram device is provided for allowing quick forcible entry through locked closures. The device includes a ram that slides within and partially out of a housing. The ram is connected to a piston which also slides within a cylindrical housing. The housing is connected to a firing mechanism that uses an explosive cartridge for driving the piston forwardly and subsequently forcing the ram partially out of its housing to deliver a blow to a closure. The piston and cylinder further include an energy absorbing mechanism for retarding the motion of the ram once it penetrates through a closure. The ram can be configured as a thin rectangular piece for allowing the ram to fit between a door knob and jamb of most doors. Other ram configurations include a punch for effectively knocking out a door lock of a steel or metal door, and a shearing head for effectively cutting a steel cable, bar, or wire.

Abstract: A percussion drilling apparatus having an outer casing, a fluted inner sleeve affixed to the outer casing, a hammer piston having a longitudinal opening therethrough adapted to fit around extensions of a cyclic valve positioned at the top of the inner casing, and a foot valve mounted atop a drilling bit at the bottom of the apparatus. An air channel positioned between the inner sleeve and outer casing is adapted to cooperate with channels on a reciprocating hammer piston to alternately drive the hammer piston up and down.

Abstract: This heavy duty equipment comprises a working cylinder, a striking piston, an upper lid and a holder of a drill bit. An anterior side duct in the wall of an upper working space of the working cylinder, communicating via an upper filling duct and a posterior side duct with a storage space provided in the upper lid, and an anterior bypass duct communicating via an axial duct in an axial pin and a posterior bypass duct with the storage space, axially define in the upper working space of the working cylinder, a compression space confined by the inner wall of the working cylinder, and further by an anterior face of the upper lid and by the external surface of the axial pin. The upper lid together with the axial pin and the in-built storage space form an assembly group in which a water valve is received.

Abstract: A reversible impact-operated boring tool and a method for reversing the direction of operation of the same rapidly and safely is disclosed. The tool according to the invention possesses a second supply line for supplying pressurized fluid to the tool. The second supply line provides pressurized fluid to a directional valve within the tool. The tool operates in the forward mode for borrowing into the soil when pressurized fluid is supplied to this directional valve. When the pressurized fluid supply is terminated and the fluid is exhausted from the valve, the tool operates in the reverse mode. The tool according to the invention can be reversed safely without any need for hose manipulation and without turning off the primary fluid supply line.

Abstract: The percussion device which can be used as a hammer drill has a drive piston for driving an overhung percussion piston which is mounted between two air cushions. Depending on the percussion travel of the percussion piston, the percussion air cushion is reversed so that a respective partial quantity is passed around the percussion piston to the opposite side by a central bypass. A no-load bypass is also provided to vent the recoil air cushion to the percussion cushion for a no-load condition. A third bypass bridges the drive piston in the top dead center position to communicate an annular chamber to the rear of the drive piston with the percussion cushion.