Abstract: A single supply line feeds hydraulic fluid under pressure to a hydraulic percussive machine with a percussion motor and a rotation motor. A constant flow device is positioned between the supply line and the rotation motor.

Abstract: An arrangement for mounting of a rotation element in a drilling machine comprising a body (1) and a rotation element (8) mounted by means of bearing surfaces (8a, 8b) rotatably in the body for rotation of a drill shank (9). The rotation element is rotated by a rotation machinery (10) in engagement with a gear ring (11) of the rotation provided in the rotation element between the bearing surfaces. In order to replace the rotation element without having to disassemble the body, the rotation element is mounted at both ends thereof in the radial direction in an integral body part (3), and the bearing surfaces and the gear ring are arranged in a stepped manner so that the rotation element is removable from the integral body part axially through one end (3c) thereof.

Abstract: A body construction for a drilling machine comprising a body provided with end covers, a percussion means mounted in the body, and a rotation means positioned on an axial extension of the percussion means for rotating a shank. In order to avoid the use of conventional tie rods, the body is formed by an integral body part, and housings for the percussion and the rotation means are formed in the body part in such a way that the percussion and the rotation means can be replaced through the corresponding end covers without having to detach from the body anything else but the end covers of the body part.

Abstract: A hammer drill includes a unit for supplying impact force to a tool inserted into the hammer drill and a unit for supplying rotational forces to the tool. A first drive motor drives the impact force unit and a second drive motor drives the rotational force unit. The motors can be operated independently of one another. A first drive train interconnects the first drive motor to the impact force unit and a second drive train interconnects the second drive motor and the rotational force unit. A coupling device interconnects the first and second drive trains so that at least one of the impact force unit the rotational force unit can be selectively driven by both the first and second motors.

Abstract: A hydraulically powered impact device for rock drilling having an impact piston driven by a hydraulic drive unit and a shank rod adapted to be struck by the impact piston. A motor imparts a rotary motion to the shank rod by rotating a sleeve through a gear train. The sleeve is rotatably mounted around the shank rod. A chuck is splined to the shank rod and a dog clutch is provided between the sleeve and the chuck for engaging both. A fluid passage is formed for introducing lubricant fluid stored in a gear casing into a chamber accommodating the dog clutch. The fluid passages includes a valve which is held open as long as the cover is connected to the main casing.

Abstract: A method and apparatus for driving a hollow pile into the ground. By using a hollow rod having a short auger fixedly secured to a leading end portion thereof, excavated earth and sand are lifted to and around the upper portion of the auger where compressed air is spouted from nozzle orifices formed in the hollow rod thereby lifting the excavated earth and sand through the hollow pile and consequently discharging the same from the hollow pile. As earth and sand are discharged from the hollow pile, the pile is sunk or driven into the ground.

Abstract: A percussion drill machine includes a drill shaft with a chuck for a drilling tool and a percussion device for imparting percussive force to the drilling tool held in the chuck. Each of the driving shaft and the percussive device has a separate electrical motor. The electrical motors can have a common stator or each motor may have its own stator. Each electrical motor has its own rotor and shaft. The shafts can be arranged coaxially with one being a hollow shaft laterally encircling the other. In another arrangement the shafts can be disposed in laterally spaced parallel relation.

Abstract: A single hydraulic supply line feeds fluid under pressure to a hydraulic percussive machine with a percussion motor and a rotation motor. The feed passes through two valves of the constant volume priority flow dividing type. The first valve gives priority to the percussion motor to the extent of establishing idling speed. The second valve in the bypass of the first valve gives priority to the rotation motor while its bypass reaches the percussion motor. Working speed of the percussion motor can only be obtained after the rotation motor is up to speed and control of the feed above the priorities controls the percussion motor speed only.

Abstract: A pneumatic motor for rock drills and the like having a reciprocating piston with valves at its opposite ends for valving motive air to the piston head from both ends of the cylinder. Large receivers are provided near the respective valves to accommodate availability of air on demand from the valves and to dampen pressure fluctuations. One of the receivers is connected to an external source of fluid under pressure; while the two receivers are interconnected by tubing external to the pneumatic motor itself. This permits the cylinder for the piston to comprise a simple tube provided with exhaust ports only. Additionally, exhaust air and oil from an air motor, which rotates the rock drill, are directed into the area between the lower end of the reciprocating piston and a striking bar for the drill rod to lubricate the reciprocating parts.

Abstract: A mechanism for reversing the direction of rotation in a drilling apparatus comprising a feeding beam (1) and a drilling machine (3) supported by the beam for longitudinal movement back and forth along the beam in a drilling direction (A) and an opposite return direction (B) by a feeding mechanism (4). The drilling machine is provided with a pressure medium driven rotating device (9) for rotating a drilling rod and with a reversing valve (13) connected to the pressure medium system of the rotating device. The reversing valve is provided with a spindle rotatable between two positions in which the rotating device rotates the drilling rod in opposite directions. The reversing mechanism comprises two actuating elements (24,27) rotatable with respect to each other. One element (24) is in rotational engagement with the spindle and is moved axially together with the spindle at least at the end of the return direction of the drilling machine.

Abstract: A striking apparatus that includes a reciprocating striking piston operable by a pressure mechanism, a cylindrical body, the improvement comprising a sleeve bushing mounted inside of the cylindrical body in slidably fitted assembly therewith. The sleeve bushing has a drive gear at one end for rotary engagement with a drive motor. A rotary tool and piston shank and piston are all integrally combined as a one piece unit and at least partly received in coaxial alignment within the tubular bushing. Spline gearage exists between the tubular bushing and the piston shank enabling co-rotational rotary movement together upon actuation of the drive gear through operation of a drive motor operatively connected therewith. A piston cylinder in the cylindrical body along with the piston is reciprocably movable in the piston cylinder. The shank has a shank face facing in the direction opposing the striking piston and with the shank face transferring the feed force from the body through the sleeve bushing to the rotary tool.

Abstract: A pile driver assembly comprising a lead, a hammer supported for longitudinal movement along the lead, a helmet at the lower end of the lead configured to receive the end of a noncircular pile, a pile guide supported for longitudinal movement along the lead and having a cross-section configured to receive the pile, and a pile rotator supported near the lower end of the lead and configured to receive the pile, the pile rotator centering and rotating the noncircular pile.

Abstract: A rock drilling method according to which the drill is subjected to successive axial strikes and is rotated around its longitudinal axis. The direction of rotation is repeatedly reversed after the drill has rotated at least one revolution in one direction.

Abstract: This invention relates to improvements in working member assemblies and is described hereinbelow with particular reference to a novel striking bar assembly for use in open front type rock drills.

Abstract: A rock drill in which there is provided an impact unit, a front head with a tool holder and rotary drive means defined by a conventional pneumatic motor having a stator in the form of a cylindrical body, a rotor accommodated in said stator and having a symmetrical cam having a uniform convexo-concavo shape with lobes of said rotor cams being engaged with the inner cylindrical surface of the stator thereby forming chambers; spring-loaded vanes are accommodated in slots provided in the stator, with said vanes being engaged with the cam surface of the rotor and dividing the chambers into work chambers and idle chambers, the number of pairs of said vanes being one less than that of the chambers; each of the work chambers is in communication with channels supplying compressed air, while each of the idle chambers is in communication with channels leading to the atmosphere. Under the action of compressed air admitted into the work chambers, the rotor is rotated along with a drill bit attached thereto.

Abstract: A hydraulic rotary percussive drill which is adapted to operate as a drill for installing rock bolts in mines is described. The drill is configured so that the shank (which holds the drill steel and bit) forms a right angle with the impact mechanism, thereby reducing the height of the drill and providing longer lengths of drill steel feed in a confined environment. A hydraulic spring force coupler transfers the impact energy from the impact mechanism to the shank, steel and bit and shapes the energy so as to provide force pulses of such length as to couple efficiently the percussive energy to the rock being drilled while reducing the strain in the steel and bit. A rotation mechanism may be mounted in the same leg of the right angle as the shank, steel and bit to rotate the steel and bit independently from the percussive action.

Abstract: A rock drill is mounted on a cradle that is axially displaceably mounted on a feed beam. The drill has a front aperture for receiving the rear end of a drill string. The drill string is freely insertable into and retractable out of a rotation transmitting wear bushing in the aperture, and a drill string retainer is mounted on the cradle. The wear bushing is also freely retractable out of the drill, and it is also held in position by the drill string retainer. The rear end of the drill is mounted to the cradle by means of a hinge connection so that the front end of the drill can be swung up when the wear bushing is to be replaced.

Abstract: A reciprocating hydraulic motor, for example for a rotary percussive drilling head, includes a piston and cylinder having a piston face exposed to the pressure in a compression chamber which is connected through ports controlled by the piston to a supply pressure at one end portion of its stroke, and to exhaust at an opposite end portion of the stroke, while between these end portions of the stroke is a compression/expansion travel during which the compression chamber is closed and the liquid in it alternately expands over a higher range of pressure and is compressed over a lower range of pressure.For returning the piston, in the direction in which liquid is compressed, one of two opposed faces of the piston is exposed to the pressure in a biasing chamber which communicates permanently with a constant pressure supply while the other communicates with the compression chamber.

Abstract: A rock drill having a hydraulic pressure reservoir formed by the drill housing, and an anvil rotation mechanism enclosed in the housing. A piston of substantial length and a mechanical hydro-operated valve means, provide favorable pulse duration and low impact velocity. The piston has only two sliding seal diameters which permits simplified valve and cylinder configuration. The friction surfaces of the fronthead drill assembly are lubricated and cooled by integration with the circulating hydraulic system. A floating seal cartridge between the piston and anvil, tends to rotate the piston with the anvil to minimize rotative scrubbing at impact.

Abstract: A hydraulic percussive machine comprising a cylinder, a piston reciprocable up and down in the cylinder, an inlet for hydraulic fluid to the machine, an outlet for hydraulic fluid from the machine, valve and timing means for controlling the operation of the piston, a chuck for holding a tool, a mechanism for rotating the chuck, a cushioning flange on the piston, a dashpot space in the cylinder adapted to be entered by the flange on overtravel of the piston on its downstroke, and a first connection for feeding fluid trapped under pressure in the dashpot space to the chuck driving mechanism as a motive for that means.

Abstract: A portable power tool wherein the housing contains a pump, a tank for a supply of oil for the pump, an electric motor for the pump and one or more hydraulic motors which receive pressurized oil from the pump and impart movements to a rotary and/or reciprocable tool, such as a rock drill or chisel. The motor which imparts reciprocatory movements to the tool is a cylinder and piston unit whose piston is rigid with a piston rod serving to strike against the tool whenever the piston performs a forward stroke. A valve assembly having a motor-driven rotary spool controls the flow of pressurized fluid to and the outflow of spent fluid from the cylinder. A spring brakes the rearward movements of the piston, and a bladder type accumulator is connected with the outlet of the pump. The tank is cooled by currents of air which are induced by a blower on the output shaft of the electric motor and which cool the electric motor before they reach cooling fins provided at the outer side of the tank.

Abstract: An air percussion boring machine comprising a percussion means, a front head with a boring tool holder, a rear head with a hole mouth washer and a boring tool rotation mechanism synchronized with the percussion means. The boring tool rotation mechanism is provided with a stator with blades secured on its internal surface at an equal distance from each other. Installed inside the stator is a rotor with blades whose number is equal to the number of stator blades. Arranged in the rotor cavity is a sleeve wherein pawls are hinged, the pawls having means for pressing the pawls to a ratchet coupled to a tail piece of the boring tool for rotating it. The pawls in each pair are coupled to each other and are used to rotate the ratchet clockwise and counterclockwise. The means for pressing the pawls to the ratchet is made in the form of air power cylinders with pistons contacting the pawls.

Abstract: An hydraulically operated striking apparatus for driving a rock drill comprises a body having an axial, cylindrical, interior space with an inwardly protruding annular member. A cylindrical piston is positioned in the space in sliding contact with the protruding annular member, and the piston has a canal in its outer surface. The body, the annular member and the piston define two annular spaces and an annular distributing valve is caused to slide within one of the spaces under fluid pressure. The two spaces communicate with each other by means of the piston canal when the piston is in a first slidable position, and the protruding annular member prevents communication between the two spaces when the piston is in a second slidable position. The piston is provided with an axially disposed extension which, in combination with an outlet, serves to permit a third annular axial space to communicate with either an inlet or an outlet at all times.

Abstract: A rock drilling apparatus comprises a hydraulically rotated drill, a percussion motor having a piston which transfers impact energy to the drill, the piston defining together with the machine housing first and second pressure chambers for receiving pressure liquid to move the piston, the percussion motor having a hydraulic circuit including a high pressure side and a low pressure side, a pressure liquid distributing valve having a control input for receiving a control pressure, the distributing valve being located in the hydraulic circuit of the percussion motor for alternately connecting at least one of the pressure chambers to the high pressure side and low pressure side, respectively, of the hydraulic circuit in response to the control pressure, the hydraulic circuit for rotating the drill being separate from the hydraulic circuit of the percussion motor and including a high pressure side and a low pressure side separate from the high and low pressure sides of the percussion motor, a control valve for cont

Abstract: An improved fluid operated rock drill apparatus having all fluid connections thereto secured to the yoke of the drill assembly by a unitary connector means. The yoke is centrally located so that the high pressure fluid being directed to the rock drill hammer piston flows through a path of reduced length resulting in a more efficient operation.

Abstract: A portable power tool wherein the housing contains a pump, a tank for a supply of oil for the pump, an electric motor for the pump and one or more hydraulic motors which receive pressurized oil from the pump and impart movements to a rotary and/or reciprocable tool, such as a rock drill or chisel. The motor which imparts reciprocatory movements to the tool is a cylinder and piston unit whose piston is rigid with a piston rod serving to strike against the tool whenever the piston performs a forward stroke. A valve assembly having a motor-driven rotary spool controls the flow of pressurized fluid to and the outflow of spent fluid from the cylinder. A spring brakes the rearward movements of the piston, and a bladder type accumulator is connected with the outlet of the pump. The tank is cooled by currents of air which are induced by a blower on the output shaft of the electric motor and which cool the electric motor before they reach cooling fins provided at the outer side of the tank.

Abstract: A drill housing is pivotally connected to the forward end portion of a boom member that swings upwardly from a frame of a mobile drilling machine. A hydraulic motor is secured to the gear housing and provides rotary power from a drive shaft through a pair of meshing gears to a drill chuck that is arranged to receive a drill bit or a roof bolt. A percussion weight is concentrically positioned within the drill housing and is axially aligned with the drill bit for imparting percussive forces to the drill bit. The percussion control is maintained through a servovalve that is supported on the drill housing and is controlled remotely by an electronic control module. The servovalve controls the flow of pressurized fluid from a source through ports in the drill housing connected to the servovalve by conduits to actuate a piston member for oscillation within the drill housing. Oscillation of the piston imparts a percussive force upon the percussion weight which is transmitted to the drill bit.

Abstract: A rock drill wherein a piston is the only moving hammer part and such piston is movable without independent valve means or the like.