Abstract: A hydraulic hammer is disclosed having a piston and an accumulator membrane disposed external and co-axial to the piston. Additionally, a sleeve is disposed between the piston and accumulator membrane, wherein the sleeve has a plurality of radial passages formed therein that fluidly connect the accumulator membrane with the piston.

Abstract: The invention relates to a percussion device having a body and a percussion piston moving therein, pressure fluid spaces in the rear and front ends of the percussion piston and pressure fluid channels for feeding pressure fluid into the percussion device. The percussion piston and the control valve comprise surfaces, which, when aligned, substantially close the pressure fluid flow from the pressure fluid space locating behind the percussion piston in front of the control valve, whereby the produced pressure displaces the control valve to another position.

Abstract: A self-adjusting end position damping arrangement includes a stroke space 9 which is delimited by a movable stroke element 7, 24 and a part of the pneumatic cylinder 1, with the stroke space 9 being connected via a connecting duct 14 to the working pressure P1 which acts on the cylinder piston 22 or to the ventilation pressure (P3) in the outlet duct 3 and the stroke element 7, 24 being acted on via a damping duct 16 by the damping pressure P2 in the damping volume 19, a non-return valve 12 is arranged in the connecting duct 14 upstream of the stroke space 9, which non-return valve 12 blocks in the direction of the working pressure P1 or the ventilation pressure (P3), respectively, and a ventilation duct 5 is provided, which ventilation duct 5 can be opened by means of the movable stroke element 7, 24 and which is connected to an outlet duct 3.

Abstract: According to one aspect of the invention hydraulic pressure pulses are created in a rock drill machine utilizing a rod (7, 7a, 7b) made of a magnetostrictive material arranged in one or more actuators (5, 5a, 5b), which exposes an impulse piston (3) in a pulse cylinder (1) to said hydraulic pressure pulses, whereby mechanical pressure pulses being transferred to a drill steel of the rock drill machine are generated in the impulse piston (3).

Abstract: A system to provide mechanical energy to well-head equipment by directing pressurized gas existing in nearby pipelines to an engine. The engine is a linearly reciprocating piston in a closed cylinder driven by pressure differentials between the gas on either side of its piston, the differential being controlled by a switching valve which directs higher and lower pressured gas to the appropriate side of the piston, and which recirculates spent gas from the lower pressure side of the piston back to the pipeline. The system is a closed system, and avoids venting or flaring gas used in the engine.

Abstract: A check valve system is for a fluid-actuated percussive drill assembly including a casing, a backhead connected with and extending into the casing, and a fluid distributor disposed within the casing. The backhead has a central axis, a supply passage extending along the axis, and an outer surface section extending circumferentially about the axis and disposed within the casing. The check valve system includes a port extending between the outer circumferential surface section of the backhead and the supply passage. Preferably, several ports are spaced circumferentially about the backhead outer surface. An annular check valve is disposed about the outer circumferential surface section of the backhead and is configured to alternately permit fluid flow through the backhead port and substantially seal the backhead port.

Abstract: A check valve system is for a fluid-actuated percussive drill assembly including a casing, a backhead connected with and extending into the casing, and a fluid distributor disposed within the casing. The backhead has a central axis, a supply passage extending along the axis, and an outer surface section extending circumferentially about the axis and disposed within the casing. The check valve system includes a port extending between the outer circumferential surface section of the backhead and the supply passage. Preferably, several ports are spaced circumferentially about the backhead outer surface. An annular check valve is disposed about the outer circumferential surface section of the backhead and is configured to alternately permit fluid flow through the backhead port and substantially seal the backhead port.

Abstract: A sealing and venting system including an improved piston is for a drill assembly. The drill assembly includes a fluid distributor within the casing with an elongated guide portion having an outer surface, a passage through the guide portion and a port between the outer surface and the passage. The improved piston is slidable within the casing and has an interior surface disposeable about the outer surface of the guide portion. A valve chamber, an exhaust chamber and a drive chamber are defined within the casing. The system includes a sealing surface disposed within the piston passage and slidably engageable with the outer surface of the guide portion to provide a seal between the piston and the distributor. The sealing surface prevents fluid communication between the drive chamber and the exhaust chamber when the sealing surface engages the outer surface of the guide portion, and is provided by an interior surface section of the piston body or by a separate ring seal.

Abstract: In a valve arrangement in pneumatic impact motors (10), the housing (40) of a distribution valve has the form of a plastic bowl (46) which is flanged outwardly at the opening and the bottom thereof. A flat valve (50) is movable between the bowl bottom, which forms one valve seat (51) of the valve housing (40), and a bowl cover member (53), which forms the other valve seat (52). The bowl flanges (47, 48) define therebetween a groove which connects with a delivery channel (39) provided in the impact motor (10), this channel delivering compressed air to the flat valve (50) mounted inside the bowl (46). The bowl wall located between the flanges (47, 48) includes calibrated side openings (57, 58) which control the delivery of compressed air to respective valve seats (51, 52) on respective sides of the flat valve (50), this air delivery being an adapted and calibrated delivery.

Abstract: An improved hydraulic motor includes a cylinder having a head end and a rod end, and a piston reciprocable in the cylinder dividing it into a first expansible chamber toward the head end and a second expansible chamber toward the rod end. Fluid under pressure from a supply source is continually delivered to the second chamber. A fluid directional valve controls the delivery of fluid to and exhaust of fluid from the first chamber for reciprocating the piston within the cylinder. The piston has valving associated therewith for controlling the operation, in conjunction with a relay valve, of the fluid directional valve.

Abstract: A hammer of the type having an impact tool driven by pressurized fluid has a hammer body portion with a closed rearward end and an open forward end and a piston longitudinally movably housed within the hammer body portion for striking a tool mounted at the open forward end of the hammer body portion, to thereby impact an object with the tool. The hammer has a fluid valve housed within the closed rearward end of the hammer body portion rearwardly of the piston and in communication with a source of high pressure fluid for driving the piston. The fluid valve has a valve body portion defining an interior chamber and a continuous exterior side wall, and a longitudinal opening in communication with the interior chamber. The valve body has a first body portion and second body portion which is identical to the first body portion and positioned longitudinally in relation thereto within the closed rearward end of the hammer body portion.

Abstract: A piston valve diaphragm for a percussion apparatus including a valve portion having a diaphragm bore and a fluid supply source. A piston having a first piston surface and a second piston surface are also included. A diaphragm is mounted in the diaphragm bore and is displaceable in a first direction which permits fluid communication between the fluid supply source and the first piston surface and limits fluid passage between the fluid supply source and the second piston surface. Displacement of the diaphragm in a second direction permits fluid communication between the fluid supply source and the second piston surface and limits fluid passage between the fluid supply and the first piston surface. The diaphragm may be formed entirely from a flexible material or may contain a rigid center portion with flexible edge portion.

Abstract: A fluid actuated percussion rock drill comprising a hollow wear sleeve and a piston slidingly disposed within the wear sleeve. Drive and return pressure surfaces bias the piston between drive and return positions, respectively. A high pressure port is included. A return chamber is exposed to the return pressure surface. A drive chamber is exposed to the drive pressure surface. A pressure sensitive valve is movable between an open and a closed position. When the valve is in the open position, the high pressure port is connected to the drive chamber. The valve includes a first valve pressure surface for exposure to the drive chamber and a second pressure surface for exposure to the high pressure port. A third valve pressure surface is exposed to an outlet pressure port. The volume of fluid travels between the high pressure port and the drive chamber when the valve is in an open position can be limited as desired for different drill applications.

Abstract: A fluid operable engine has a cylinder in which a piston slides up and down. The cylinder has a cylindrical wall and two end walls. The piston divides the cylinder into two chambers. The piston is hollow, has a cylindrical wall and two end walls, with a rigid tube extending from and through one end wall of the piston through an adjacent end wall of the cylinder so that the interior of the piston communicates with the exterior through the tube. The cylinder has an aperture in each end wall or in its cylindrical wall close to the end walls and the piston has an opening in each of its end walls. A closure member is provided for alternately closing the openings or the apertures as the piston reaches each end wall. The engine is operated either in a positive or negative manner, with fluid being charged into or sucked from the piston or the cylinder. The openings may be closed from within or without and the apertures may be closed from inside or outside. The closure member may be mechanically or fluid operable.

Abstract: Control valve means for a driving tool operated with compressed air for the driving of fasteners into workpieces. Through a specific design of the main and the auxiliary valve and through a connection to the piston return chamber the control of the valves are brought into synchronization with the movement of the working piston. By this, high repetition frequencies can be achieved. Further, in the mode "automatic operation" also single shot operation is possible.

Abstract: A piston for a striker is displaceable in a cylinder and forms compartments on opposite sides which can selectively be connected by hydraulically controlled valve elements to a pump and to an accumulator. A hydraulic controller for the valve elements initially connects a compartment on one side of the piston to contribute the pressure from a respective compartment to the accumulator during a lifting operation, cuts off the valve element affording this pressure accumulation to brake the piston, and other such valve elements enable the accumulator to be charged with the piston in its raised position so that, upon triggering by the controller of the valve elements, the pressure which drives the ram is equal to the total pressure delivered by the accumulator and the pump to the piston.

Abstract: A control valve assembly for a pneumatic paving breaker which enables the maximum amount of energy to be imparted to the piston on its working stoke while restricting the energy imparted to the piston on its return stroke and which utilizes a reduced consumption of air, has an optimum speed of response and is relatively cheap to manufacture. This is achieved by having a valve member in the form of a pure cylindrical slug which reciprocates in a valve block in which it is a clearance fit.

Abstract: A compressed-air pile-driver, especially for axially insertable tools, including a ram arranged in a housing. The interior of the housing is divided by the ram respectively into an upper compression or expansion chamber and a lower compression or expansion chamber, which can each be alternately connected to a compressed-air source via air connection pipes and a control valve, with each having an air-outlet orifice opened alternately by the ram. In the upper expansion chamber, a pressure chamber, into which the upper air connection pipe of the upper expansion chamber opens, is divided off by an intermediate plate which is approximately parallel to the end face of the ram. Located in the intermediate plate is at least one orifice which connects the pressure chamber to the upper expansion chamber, and which is closed in a leak-proof manner by the ram in its upper dead-center position, the ram additionally being retained firmly in its upper dead-center position by a retaining device.

Abstract: A paving breaker for the construction industry of the type having a vibrating moil point or tool steel impacted by a pneumatically reciprocated piston including a double walled cylinder slidably receiving the piston designed so that the space between the inner and outer walls of the cylinder forms a passageway for delivery of piston return air to the lower cylinder chamber and the space also forms an accumulator for air compressed by the piston during the lower part of its power stroke. In one embodiment an outer cylinder sleeve is mounted on an elastomeric member surrounding an inner cylinder sleeve, and is free to reciprocate a limited distance in the housing to partly balance the reaction forces of the piston. This double walled cylinder is surrounded by rectangular polyurethane covers that form an air exhaust space around the cylinder so that exhaust air assists in cooling the cylinder.

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: This invention pertains to a fluid actuator having piston chambers, a piston maintained within said chambers, a valve means for reciprocating the piston and a pressure control means for varying the force to the valve means wherein the reciprocating frequency of the piston is modulated.

Abstract: A hand-operated pneumatic impact machine comprising a hollow body with an axially-reciprocating impact ram inside which forms, together with the body, variable-volume working chambers. It also comprises a distributing space communicating with the working chambers and with a source of compressed air. There also is a valve in the form of a cylindrical bushing whose inner surface covers at least one hole which admits compressed air into the distributing space, the compressed air forcing the valve to cover alternately the inlet channels of the working chambers for reciprocating the impact ram. The valve has at least one longitudinal channel which is in constant communication with the source of compressed air through a hole which connects the distributing space with the source of compressed air, the channel being intended to deliver compressed air to the inlet channels of the working chambers.

Abstract: An impactor apparatus including novel means for actuation of a motive fluid flow control valve or comparable motive fluid control means.

Abstract: A pneumatic drive for a hammer tool has a cylinder; a piston slidably received in the cylinder and dividing the inner space of the cylinder into two cylinder chambers; a drive output member formed as a piston rod attached to the piston and projecting from the cylinder; a pressure-responsive valve for admitting compressed air alternately to the cylinder chambers; and a plurality of spaced, serially arranged cylindrical discharge ports in the cylinder wall for releasing compressed air alternately from the cylinder chambers dependent upon the position of the piston with respect to the discharge ports.

Abstract: Fluid-actuated percussion mechanism includes a housing with an internal cylindrical space receiving a reciprocating piston dividing the space into a working stroke chamber and an idle stroke chamber. The mechanism further includes fluid distributing means mounted in the housing and communicating the chambers and the source of the working fluid. The housing also accommodates a work-performing member adapted to receive impacts from the piston. The distribution means includes at the inlet of at least one of the chambers a valve made in the form of a resilient annular element. The surface of the distribution means has made therein valve seats of which the number corresponds to that of inlets for supplying the working fluid into the chamber.

Abstract: A demolition tool for breaking solid materials, particularly rock or concrete in tunnelling, mining, demolishing and excavating applications. The tool has a single impactor (1) of the projectile type which is driven by high pressure liquid towards the material to be broken. A gas pressure accumulator (2) is included for storing high pressure energy. This energy is transferred at a high rate through short, wide and streamlined channel means (8, 13, 57, 9), having high capacity and low flow losses, to the impactor (1). Valve means (7) is provided in the channel means so that the accumulator (2) can be recharged during the return stroke of the impactor, giving a high repetition rate. A low pressure annular accumulator (5) drives the impactor during the return stroke.

Abstract: A hydraulically operated reciprocating piston and a differential force operated valve are both in continuous fluid contact with a pressurized cushion chamber as well as the piston chamber pressure. The valve position is a function of the cushion chamber pressure. The cushion chamber pressure is a function of the axial position of the piston. The values of these functions are such that the piston is reciprocated when the machine is operated. The valve is a sleeve coaxial with the piston.

Abstract: In a percussion tool a means is provided for delaying the manifestation, on a valve means sensitive to such change in pressure, of a change in pressure of the fluid applied to the hammer piston at one end thereof and which drives such hammer piston in its working stroke, the valve means being that means which serves to control the inlet and exhaust parts of the fluid circuit which applies pressure to the other end of the piston.

Abstract: Impact tools are described which are capable of developing percussive forces for rock drilling and other repetitive high force applications. A hydroacoustic oscillator contained in such tools includes a hammer and a valve mechanism which is actuated by the hammer for controlling the flow of pressurized fluid so as to establish pressure variations which sustain the oscillation of the hammer. A number of alternative valve mechanisms are disclosed, each including a valve element, the motion of which is controlled by controlling the flow of fluid with respect to the valve element as the hammer and valve element move relative to each other. Such flow control is afforded by chambers defined by the valve element; hydraulic fluid flow with respect to which is controlled so as to determine the deceleration of the valve element and the motion of the element in its actuation by the hammer.

Abstract: An improved air reversing valve, as for use with a pneumatic scaler, chisel or the like, comprising throttling means between the two sides of the valve disc whereby the tool's performance characteristics are generally improved. Additionally, the valve is made multi-element whereby its manufacture is simplified, as by powdered metal casting internal passageways in facing surfaces of adjacent parts, rather than cross drilling or the like.

Abstract: A fluid operable engine has a cylinder in which a piston slides up and down. The cylinder has a cylinder wall and two end walls. The piston divides the cylinder into two chambers. The piston is hollow, has a cylindrical wall and two end walls, with a rigid tube extending from and through one end wall of the piston through an adjacent end wall of the cylinder so that the interior of the piston communicates with the exterior through the tube. The cylinder has an aperture in each end wall or in its cylindrical wall close to the end walls and the piston has an opening in each of its end walls. A closure member is provided for alternately closing the openings or the apertures as the piston reaches each end wall. The engine is operated either in a positive or negative manner, with fluid being charged into or sucked from the piston or the cylinder. The openings may be closed from within or without and the apertures may be closed from inside or outside. The closure member may be mechanically or fluid operable.