Abstract: The invention relates to a hammering device for influencing the subsurfaces of workpieces comprising a beating tool for acting on the workpiece, a beating mechanism which has a first beater for producing a beating pulse on the beating tool, and a drive for driving the beating mechanism, wherein the beating mechanism has at least a second beater for producing a beating pulse on the beating tool. According to the invention, it is intended for the beating mechanism to comprise a drive shaft that extends along a drive axis and a wobble ring for transforming a rotational movement of the drive shaft into a translational movement, and the first beater and the second beater to be driven by the wobble ring.

Abstract: A plurality of weight hammers (7,8) are provided, and each of the plurality of weight hammers has a shape for substantially evenly applying a hammering force with respect to a surface to be hammered of an object to be hammered (11), about a center line of the object to be hammered. Rotors (9, 10) for driving the weight hammers (7,8) are provided to the same rotating shaft (22) in such a positional relation that an engagement claw (9a) of one rotor (9) engages and drives one weight hammer (7), and, when engagement of the weight hammer (7) is released, an engagement claw (10a) of another rotor (10) in driving engages another weight hammer (8). The rotors are driven by the same driving means (26).

Abstract: An arrangement for installing building elements, such as piles and tunnel sections, into a ground formation, where a building element is provided. Two or more impact drivers for delivering blows to the element are mounted on or operatively connected to the element. Accordingly, large elements, such as monopiles for wind turbines, which may comprise a steel tube having a diameter in excess of 5 meters, or even tunnel sections, can be installed by utilizing a number of relatively small impact drivers.

Abstract: A powered hammer includes a housing, a tool holder coupled to the housing and configured to hold a tool, a motor within the housing, a piston slideably mounted within the housing, a drive mechanism that converts rotary output of the motor into a reciprocating motion of the piston, a ram slideably mounted forward of the piston and that is reciprocatingly driven by the piston, and a beat piece support mounted in the housing forward of the ram. A beat piece is slideably supported by the beat piece support. The beat piece is repetitively struck by the ram and that in turn repetitively strikes an end of a tool when the tool is held in the tool holder to transfer the momentum of the ram to a tool. The beat piece support includes a seal that is slidingly engaged by the beat piece. The seal includes an absorbent material.

Abstract: An impact mechanism for a hammer drill, which has a housing and a drill bit protruding outside the housing, is provided. The mechanism includes firstly an impact platform within the housing; the impact platform is in connection with the drill bit for receiving impact forces and for transferring the impact forces to the drill bit. The mechanism also has a plurality of cams within the housing, and the plurality of cams are angularly spaced apart and arranged about an axis of rotation. The mechanism further includes a plurality of hammers placed within the housing and interactable with both the impact platform and the plurality of cams. The plurality of hammers are angularly spaced apart and arranged about the axis of rotation, and each hammer is capable of reciprocating along the axis for exerting the impact forces on the impact platform.

Abstract: The conventional rapper design is improved to provide longer service without maintenance and easier access at less cost when service is required by, among other things, redesign of the hammer assembly, hammer shaft and lever assemblies, and the hammer assembly housings. Design improvements include the provision of access panels on the housings, a guide and lock mechanism for removing and inserting the hammer assembly out of and into the hammer assembly housing, providing the hammer with a removal, and keyed engagements of hammer shaft assembly components.

Abstract: The breaker device for removing the tops of columns comprises a support structure composed of a plurality identical chain elements reciprocally linked by link couplings to form a closed chain which can surround a column which is to be topped. Each chain element bears a jackhammer provided with a plurality of interchangeable breaker punches, of varying lengths. Each chain element exhibits a plurality of holes which are distanced from the link couplings and which are for linking the chain elements. Each hole is aligned with a corresponding hole of an adjacent chain element. A pin is used for blocking adjacent chain elements in predetermined positions. The invention is useful for breaking the stop of a reinforced-concrete column without damaging the reinforcement elements thereof. The device can be adapted to columns having different diameters.

Abstract: A substrate breaking apparatus and method including a frame and a plurality of independently controlled hammers movable between a lowered position and a raised position.

Abstract: An impact device having a housing with hollow cylindrical aperture therein. The cylindrical aperture has a rotatable member within. The rotatable member has axial multiple rods thereon. On each rod of the rotatable member there are captive annular masses with a central aperture larger than the diameter of the rod to permit radial movement of the masses with respect to the rod. The rotatable member is driven by a motor and in turn rotates the annular masses which strike impact tools also supported within the housing. The kinetic energy of the annular masses is thereby transmitted via the impact tools to the outside of the impact device.

Abstract: The percussion mechanism of this device, comprising a cylinder, a free piston, an anvil, a tool holder in which a bundle of needles is disposed, the heads of which are applied to the anvil, is mounted to slide in a tubular housing between two springs used to insulate dynamically the percussion mechanism of the housing and of the handle which holds it. The cylinder is mounted in the housing by a suspension comprising two annular seals and the cylinder is set with a clearance so that the centering provided by the seals insulates mechanically the cylinder of the housing and reduces the transmission of vibrations.

Abstract: A surface-chiseling machine for refractory, concrete or other materials is disclosed, which includes a piston having at its one end a step portion and on a side periphery at its other end a through-hole, and a cylinder forming a first air chamber on a closed side of the step portion of the piston, forming an exhaust channel communicated with the through-hole of the piston and having an air hole for feeding a compressed air to the first air chamber. The cylinder at its rear end is closed with a back head for forming therein a second air chamber, while at its front end is closed with a front head which is provided with a plurality of chisel-inserting holes, into which are inserted chisels with their rear ends being contactable directly with a front face of the piston for providing a striking action on the chisels.

Abstract: The invention concerns a consolidating plank for a highway finishing machine the basic plank body of which is lengthenable by a manually attachable plank or by an extendible plank. For creating such a high compacting effect that a subsequent following compaction is saved, a stamp unit having at least two stamps is provided, which stamps have a common eccentric support.

Abstract: A chopping hand tool, including a slidable hammer along a handle of the tool for striking against a hammer stop mounted on the handle, so to transmit the hammer striking force to a toothed edge of a blade affixed to one end of the handle, so that the toothed edge is used to chip materials against which it is applied.

Abstract: A knocking arrangement for cleaning electrodes of an electric precipitator has a plurality of hammer members mounted on a rotary shaft, a plurality of anvil members arranged so that the hammer members strike against the anvil members, and connecting elements including a V-shaped holding member with a closed end portion embracing one frame member of a frame of the precipitator, and an open end portion provided with two projections, wherein a wedge member carrying the anvil member is received into the holding member between the projections and the one frame member.

Abstract: Conventional apparatus for assembling a track chain tend to impose undesireable bending moments and residual loads thereon. The apparatus (22) of this invention overcomes these problems by providing a pair of movable pressure heads (26,28) registering with first and second contact points (142,144) on opposite ends of a chain link (134) and a pressure equalizing plate (68) for sensing the resistance force at each contact point (142,144) to direct an increased pressure to a selected one of the contact points (142,144) in response to the differential between the resistance forces at the contact points (142,144).

Abstract: An elongated tool is mounted for reciprocal motion on a support frame. A plurality of resonant force transmitting beams each having an input, an output, and at least one resonant node, are supported by the frame so their outputs are spaced apart adjacent to the length of the tool. A sonic generator operating at or near the resonant frequency of the beams is coupled to the beam inputs to produce at the beam outputs resonant vibration about a neutral position. Each beam is pivotally mounted for rotation about its resonant node and such rotation is rigidly limited such that the spacing between the neutral position of the output of each beam and the tool is the same, which synchronizes coupling of force from the beam outputs to the tool. The pivotal node support comprises a closed hollow annular elastic housing and a fluid filling the housing.

Abstract: An impact mechanism for rock breaking, pile driving and pile extracting, and the like, includes a head assembly (18) with a pair of shank members (24,26) movably mounted thereto and flywheel (76,78) and eccentric crankshaft parts (74) rotated by a motor (84). The crankshaft parts (74) intermittently contact one of the shank members (24,26) to drive it outwardly from the head assembly (18) by transmitting flywheel energy thereto. A biasing and dampening device (110) associated with each shank member (24,26) absorbs rebound energy from the shank member (24,26) and maintains the shank members (24,26) disengaged from the crankshaft parts (74) until it is positively urged thereagainst. The head assembly (18) is movably mounted at the end of an articulated arm (10) for maneuvering it into desired work position.

Abstract: The invention herein relates to an undercutting device which is provided with a substantially tubular body adapted to be placed within a parallel-sided hole. A rotary percussion head is provided at one end of the body and has one or more cutting tools which extend radially therefrom at an obtuse angle and which cutting tools are adapted to cut outwardly from the radius of the body, means are provided for rotating the head about the axis of the body and for operating the percussion head at one predetermined depth in the hole so that the cutting tools may act on the wall of the parallel-sided hole.

Abstract: A multi-vibro pile hammer comprising a plurality of vibro pile hammers having vibration generating units adapted to generate vibrations with different phases and in synchronism with one another, and the arrangement is made such that vibrations to be transmitted through the ground between the piles or sheet piles held by the hammers so as to be driven underground or pulled out therefrom can be counteracted thereby reducing the vibration transmitting region remarkably.