Abstract: An electromagnetic pile driver has an elongated guide in which a magnetic core is permitted to fall by gravity to impact against an anvil transmitting the impact energy to the pile. The core is raised by a coil in a ferromagnetic sheath disposed at an upper portion of the guide and an upper anvil can be provided and coupled to the pile when the apparatus is used for withdrawing piling. The coil is energized by the control discharge of a capacitor.

Abstract: A hand-held electrically powered hammer tool with a rotor-type electromotor (17) and a hammer mechanism (14) arranged in a machine housing (13). The hammer mechanism (14) includes a drive shaft (24) with an excentric crank pin (35) thereon for a piston rod (43) connected to a drive piston (40) reciprocably movable in a cylinder (42) for driving a hammer piston (41) towards a working tool (16) via an air cushion (44) between the two pistons. The drive shaft for the hammer mechanism (14) is also the rotor shaft of the electromotor (17) so that the hammer mechanism and the motor are driven by the same speed. The electromagnetically active parts (23,49) of the rotor (18) are located outside of and surround the corresponding parts (21, 22) of the electromotor stator (19) thus enabling the rotor also to be a flywheel and a fanwheel.

Abstract: The present invention relates to a new and improved piezoelectric high voltage impact mechanism including a hollow housing means having groove means with two portions and a shoulder portion at their juncture, provided on its inner surface, an actuator means having two projections slidably received in the upper portion of the groove means, a hammer means with two lug members movably received in the lower portion of the groove means and an actuating spring means torsionally connecting the actuator means and the hammer means so that the hammer is held on the shoulder in the housing as actuation is initiated. Energy is stored in the spring during actuation and the actuator pushes the hammer off the shoulder, initiating an impact in a straight-line avoiding unnecessary dispersal of energy and ensuring a stable high voltage pulse.

Abstract: A motor-driven hammer may include an air motor, a DC motor operated from rechargeable batteries, or an AC motor operated from the commerical power supply. In one embodiment, the motor is coupled to reciprocate the hammer head by way of a cam is a tension spring. In the second embodiment a compression spring is employed in conjunction with a cam which releases the hammer head upon full compression of the spring.

Abstract: Power driving apparatus includes a body portion, a power supplying portion, an actuating portion, a drive portion, a biasing portion and a surface contacting portion. The body portion includes a vertically oriented elongated tubular section, the tubular section including a substantially open lower end. The power supplying portion includes a power source affixed to the body portion spaced from the open lower end thereof, the power source including an output shaft member disposed transversely of the body portion. The actuating portion includes a rotatable eccentric supported transversely axially within the body portion, the eccentric being spaced from the open lower body end substantially parallel to the output shaft member. An arm member has one end pivotally connected to the eccentric and extends therefrom downwardly toward the open lower body end. A weighted hammer section is supended from a lower free end of the arm member and disposed within the body portion.

Abstract: An electrically driven hammer machine comprising a driving piston (103) and a hammer piston (104) driven by the driving piston via a pressure gas cushion (106). The driving piston is driven by a brushless alternating current motor (101) via a crank mechanism (105). A solid state inverter (107) in the power supply conduit (102) supplies power of variable amplitude and frequency to the motor.

Abstract: An electrically-operated multi-needle chisel tool including a housing having a front portion and a rear portion. An electric motor is mounted in the rear portion. A cylinder extends forwardly from the front portion of the housing. A piston is disposed in said cylinder for reciprocable linear motion which is converted from the rotary motion of the motor. An anvil is axially slidably supported in the cylinder and positioned forward of the piston so as to be hit by the piston. A needle supporter is axially slidably supported in the cylinder and positioned forward of the anvil so as to be hit by the anvil. A number of needle chisels are individually supported by the needle supporter for axially slidable movement, and a return spring disposed in the cylinder for returning the needle supporter, the piston, the anvil and the needle supporter being adapted to be synchronously reciprocated by the motor. The piston includes a base portion and a reduced diameter shaft portion extending forwardly from the base portion.

Abstract: Disclosed herein is a percussive tool having a piston and a ram slidably mounted within a cylinder which is axially displaceable. An air chamber is defined in front of the ram, and the cylinder has exhaust openings formed therein. With the cylinder in its retracted position, the exhaust openings communicate with the front air chamber so that the air cushion therein is vented during forward movement of the ram, and with the cylinder in its advanced position, the exhaust openings are closed to seal the air chamber so that the ram is limited in its rearward movements.

Abstract: In a drill hammer a motor driven striking mechanism is provided with two air cushions of changeable volumes, through which impact energy is transmitted from the motor to a reciprocating striker which in turn transmits the energy to a tool of the drill hammer. When the striker moves in the direction towards the tool both air cushions act on the striker whereas when the striker moves away from the tool only one of two air cushions acts on the striker.

Abstract: In a drive-in apparatus for driving fasteners such as clips, nails, tacks, staples and the like in a workpiece, a solenoid for actuating impact blade which ejects the fastener is movably arranged in the apparatus housing. The solenoid includes an exciter coil formed with a central opening in which a cylindrical armature connected to the impact blade is magnetically accelerated in forward direction and returns to the starting position by a resetting spring. The exciter coil is also movably guided within the housing and spring biased in the forward direction by another biasing spring having a progressive elasticity characteristic. Depending on the steepness of the characteristic line of the second biasing spring, the backstrokes of the apparatus and the force necessary for tacking operation can be adjusted in broad range.

Abstract: A power tool has a changeover mechanism for varying at least one operational mode of the power tool. A rotatable control member having a lateral periphery is connected to the changeover mechanism. A detachable cover plate, forming part of the housing of the power tool, has an aperture therein through which the control member protrudes, and the lateral periphery of the control member is covered by the cover plate. A latching arrangement comprises a first latch component formed in said lateral periphery, and a second latch component located on the underside of the cover plate, the first and second latch components cooperating to retain the control member in a selected position, and one of these latch components is resilient. Preferably the second latch component is resilient and may be formed integrally with the cover plate. The cover plate may have two apertures for two control members with a common resilient latch member on the cover plate for both control members.

Abstract: A hand-held power tool, for example a rotary percussive drill, includes a component for undergoing linear movement and a bearing support for the component. The bearing support comprises a cylinder formed from sheet metal strip with the longitudinal edges spaced to form a gap in the wall of the cylinder. By making the bearing support from a sheet metal strip and providing a gap in the cylinder wall considerable cost savings are achieved.

Abstract: A hand-held motor-driven percussion tool comprises a piston driven over an air cushion and acting over an axially movable anvil on the inner end of a tool axially movable in a tool receiver provided at one end of a tool housing. The anvil has an annular collar located in the cavity of an impact body which is movable in the direction of the impact of the piston against a cushioning ring. The impact body has an abutment face adapted to be engaged by a collar of the anvil when the latter is driven by the piston. A face of the impact body facing away from the cushioning ring is directed toward a part fixedly connected with the tool housing. The mass of the impact body is for instance 10% greater than that of the anvil. If the tool during operation is withdrawn from a workpiece, then the flange of the anvil impinges upon the abutment face of the impact body and accelerates the latter towards the cushioning ring.

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 power operated tool includes a prime mover, an output member and a power transmission mechanism arranged to transmit rotary motion of the prime mover to a reciprocatory output member. The power transmission mechanism includes a first member mounted for reciprocating motion, a link coupled at one end to the first member, and a second member mounted for rotation about an axis transverse to the path of reciprocating motion of the first member. The arrangement is such that rotation of the second member reciprocates the first member and also imparts a cyclic partial rotation to the first member during said reciprocation. The second member has a bore therein spaced from the axis of rotation and inclined there towards. The bore has an axis which intersects the axis of rotation at an angle of about one quarter of the angle through which the first member partially rotates.

Abstract: A Precipitator Rapper is disclosed having a non-magnetic tube adjustably attached to a solenoid and a hammer extending through the solenoid and through the tube. The solenoid is adjustable toward and away from the precipitator and the tube has a removal cap on the end remote from the precipitator that can be removed so that an accurate measurement can be made from the hammer to the outer end of the tube. This enables a person to accurately adjust the hammer relative to the tube.

Abstract: The present invention relates to pile-driving apparatus, particularly for under-water use. The pile driver basically comprises a linear induction motor having a tubular stator including a plurality of axially spaced stator coils. The slider or armature of the motor comprises the pile to be driven.

Abstract: Semi-automatic, powered nailing is provided preferably by power from a commercially available electric impact torque wrench. The wrench is fitted with a hammer mechanism converting wrench torque to hammer blows. The hammer provides power to a nail feeding mechanism. The nails are in strips in which the nails are in a series one behind another. The feeding mechanism severs the series of nails and/or completes the formation of nails. The nails preferably are formed by hollow tubing cut between nails defining a plurality of points therearound on one side of the plane of nail division and defining a plurality of head forming tabs therearound on the other side of the plane of nail division.

Abstract: A carpet stretcher device comprising a body case having a handle fixed to the upper surface thereof, an electromagnetic coil axially installed in the body case, a plunger axially slidably fitted in the inner surface of the electromagnetic coil and normally urge rearwardly by a spring, and a spindle fixed to the rear end of an engaging head for engagement with carpets and axially slidably fitted in the front end of the body case, the arrangement being such that upon energization of the electromagnetic coil the plunger is advanced to strike the rear end of the engaging head with its front end.

Abstract: An impact device (15) applies hammer-like blows, or impact forces, to a metallic support frame (13) from which high-voltage electrodes (10) are suspended in an electrostatic precipitator in order to dislodge accumulated particulates from high-voltage electrodes (10). The impact device (15) is electrically isolated by an insulator (19) from metallic components of the precipitator other than the support frame (13) and components electrically connected to the support frame (13). The insulator (19) has a bore (18) that accommodates movement of the impact device (15) from a withdrawn position away from the support frame (13) to an impact position in contact with the support frame (13) upon energization and de-energization of a solenoid (17). The insulator (19) remains unstressed as the impact device (15) contacts the support frame (13).

Abstract: An electrically operated tool is disclosed for inserting one or more insulated electrical wires into a barrel shaped, slotted terminal. A modified solenoid provides a hammer action power stroke which is initiated by partially retracting the toolhead inwardly of the tool upon movement of the tool against the barrel terminal. A trigger circuit applies line voltage to the solenoid windings, saturating the core, to provide rapid power stroke, so that the solenoid armature hammers against a strike plate of the toolhead. The trigger circuit includes a high and low power adjustment.

Abstract: A hand-held power tool has a tool holder for holding a tool, a striking mechanism including a cylindrical sleeve, a drive piston reciprocable in the sleeve, and a striker actuated by the latter, and a drive motor located axially parallel with and laterally adjacent to the cylindrical sleeve. The drive motor transmits the movement to the striking mechanism through a crank drive which is a one-stage crank drive and has a drive train extending transversely to a longitudinal axis of the cylindrical sleeve. The crank drive includes a rotatable shaft, a bevel gear fixedly mounted on one end portion of the drive shaft and meshing with a drive pinion of the motor, and a crank lever mounted on the other end portion of the drive shaft and connected with the drive piston of the striking mechanism. A fan is mounted on the motor shaft and operative for aspirating air, so that air flows through the motor, then flows around the cylindrical sleeve of the striking mechanism and then discharges toward the tool holder.

Abstract: A method for disintegrating a material comprises acting on the material being disintegrated with shock waves produced upon applying individual electromagnetic field pulses to a current-conducting element arranged in a close proximity to the material being disintegrated. An apparatus for disintegrating a material comprises a unit forming electromagnetic field pulses connected to a current source and arranged in a close proximity to the current-conducting element.

Abstract: A percussive tool includes a tool member and a member imparting strikes to the former. The tool member is located in a tool casing which is movable relative to a housing. A spring is located between the tool casing and the housing so as to substantially prevent transmission of impacts from the former to the latter. The tool housing is provide with a recess at a trailing end thereof into which a leading end of the imparting member can be received whereby the imparting member does not make contact with the tool casing. The axial length of the recess is such that when the tool casing is urged rearwardly to its initial position, a wall surrounding the recess surrounds the leading end of the imparting member.

Abstract: A power hammer having an elongated hammer element disposed in a tubular housing for reciprocating motion therein and having a cylindrical cam concentrically mounted with respect to the tubular housing for displacing the hammer element against the force of a compression spring. When a point in the cam profile is reached which drops off abruptly, the hammer element is driven against an anvil member also disposed in the tubular housing. The cam is adapted to be driven by either an electric motor or another suitable source of rotational power.

Abstract: The housing for electric tools comprises a one-piece plastic construction and includes a handle part and a hollow housing part having a metal jacket therein which defines various cavities and bearing bushes and bores for the elements of a drive motor and an eccentric drive for a hammer drill.

Abstract: An apparatus for utilizing electromagnetic energy for producing high impact forces by means of a ram propelled against a work piece. The work center of the apparatus includes a ram assembly of bolted construction having a hollow ram shaft, which ram assembly includes a gap between opposing conductive surfaces including associated fastener screws of driving disc and ram shaft of at least about five-sixteenths of an inch. A solid mass recoil assembly provides integral housing and recoil mass, enabling aerostatic bearing functioning, and also lowers shock and vibration levels to operator and equipment.

Abstract: A mechanical vibrator or tapper is shown in which a high intensity permanent magnet armature moves within the field of a coil of wire wound about the magnet. The magnet is guided for reciprocal motion within a spool containing the winding and strikes impact pads at opposite ends of the central spool opening. The magnet consists of two permanent magnets bonded to one another with like poles facing one another and is freely movable within the spool opening and is guided therein. A permanent magnet is fixed at one end of the spool opening and forces the permanent magnet assembly to reverse its motion after the magnet field of the winding drives the armature magnet against the impact pad at that end of the spool opening, and the magnetic field of the coil goes to zero. An oscillator circuit for driving the system is contained on printed circuit boards mounted within the housing which encloses the vibrator structure. The housing is crimped together in its final assembly.

Abstract: An apparatus for utilizing electromagnetic energy for producing high impact forces by means of a ram propelled against a work piece. The work center of the apparatus includes a ram assembly of bolted construction having a hollow ram shaft, which ram assembly includes a gap between opposing conductive surfaces including associated fastener screws of driving disc and ram shaft of at least about five-sixteenths of an inch. A solid mass recoil assembly provides integral housing and recoil mass, enabling aerostatic bearing functioning, and also lowers shock and vibration levels to operator and equipment.

Abstract: An electrode rapper assembly for electrostatic precipitators which increases the life of switches used to energize the rapper and will not be damaged if improperly connected. The rapper assembly has a solenoid and two diode rectifiers, one being connected in parallel with the solenoid coil and the other in series with the coil.

Abstract: Rotary-powered exciter-reciprocative means are disclosed by which improvements in efficiency and effectiveness of impact devices, effected by important reductions of wasteful extraneous harmonic vibrations through the use of long double connecting rods, are obtainable in selected embodiments incorporating gearing, by which a smaller lighter weight rotary motor of different rotational frequency from that of the impacting can be utilized.

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 electric hammer comprising a housing accommodating a stator, a hammer piston reciprocably mounted in the stator, and a shock absorber including a resilient member and an intermediate member disposed between the hammer piston and the resilient member, the mass of the intermediate member being greater than that of the hammer piston.

Abstract: A power driven crankshaft is mounted on a frame and is connected by a pair of connecting rods to a coupler body, having guide means thereon to limit movement of the body to straight line reciprocation. Selected positioning and arrangement of crankshaft, bearings, connecting rods, journals, wrist pins, power drive means, reciprocating body guide means and selected crankarm result in high impact force being delivered to an impact tool with significantly reduced energy loss caused by oscillatory structural deflections spurious vibrations, and rotations. An improved coupler incorporates an air spring with selected central vent means resulting in nearly constant spring stiffness.