Abstract: The invention provides a novel jackhammer that utilizes ultrasonic and/or sonic vibrations as source of power. It is easy to operate and does not require extensive training, requiring substantially less physical capabilities from the user and thereby increasing the pool of potential operators. An important safety benefit is that it does not fracture resilient or compliant materials such as cable channels and conduits, tubing, plumbing, cabling and other embedded fixtures that may be encountered along the impact path. While the ultrasonic/sonic jackhammer of the invention is able to cut concrete and asphalt, it generates little back-propagated shocks or vibrations onto the mounting fixture, and can be operated from an automatic platform or robotic system.

Abstract: The tool comprises an engine for propelling a piston including a shaft for driving a fastening member into a supporting material and through a pin guide, with means for adjusting the depth of drive of the piston shaft outside the pin guide at the end of the propulsion and at the stop of the piston in abutment against stop means. The pin guide is mounted free in translation and the depth of drive adjusting means comprise an adjustment knurl with a knurl shaft arranged so as to be in abutment against the pin guide and to push the pin guide forwards under the rotation action of the knurl.

Abstract: A vibration generator for a vibration pile driver has imbalance masses that can rotate and which are disposed on shafts. The rotational position of the imbalance masses can be adjusted relative to one another. A control and regulation circuit is provided which has a memory unit for storing ground composition data sets or task-specific default data sets with defined operational characteristic variables. The unit also has sensors for continuous detection of the defined operational characteristic variables, an evaluation unit for comparing the operational characteristic variables that are determined with the operational characteristic variables of the selected default data set, a regulation device for regulating the vibration generator, and a control device for controlling the adjustment of the rotational position of the imbalance masses relative to one another. The vibration generator is part of a vibration pile driver.

Abstract: A vibratory pile driver configured to insert curved sheet pile beneath a conduit by rotating the pile driver about a fixed pivot element to advance the curved sheet pile along a fixed arc. In one exemplary embodiment, the distance between the fixed pivot element and the clamps that secured the curved sheet pile to the pile driver is the same as the radius of curvature of the curved sheet pile. In another exemplary embodiment, when the curved sheet pile is secured to the pile driver by the clamps, the center of the radius of curvature of the curved sheet pile lies substantially on the rotational axis of the fixed pivot element. In this embodiment, the vibratory pile driver may be rotated about the fixed pivot element to advance the curved sheet pile along an arc having curvature substantially identical to the radius of curvature of the curved sheet pile.

Abstract: A sonic drilling apparatus having a work piston within a cylinder chamber to provide a vibratory force through the alternate application of fluid under pressure into the bore above and below the piston in a manner that the piston will be forced to reciprocate within the bore. The cylinder chamber includes an inlet gallery to allow fluid under pressure to pass into the bore above a first face of the work piston and an exhaust gallery to allow fluid to escape from the bore below the second face of the work piston. A relief bypass is provided to prevent excessive build up of pressure in the bore during the reciprocating movement of the work piston.

Abstract: A concrete drill for drilling concrete or the like by a diamond bit (5) attached to a front end of a bit drive shaft (4) projected forward from a main body (1) by driving to rotate the bit drive shaft (4) by a drive source (2) contained in the main body (1) in which the main body (1) is provided with a vibrating apparatus (8) for exerting a vibrating force a magnitude which is pulsated to change along the bit drive shaft (4) to the main body (1).

Abstract: A pile driver includes an attachment frame fixed to a work arm of appropriate construction equipment that serves as a base machine, a vibration cylinder actuated and controlled by an electro-hydraulic hydraulic servo-valve and mounted on the attachment frame through a rubber buffer, and a counter weight and a chucking means for gripping a pile to be driven K provided on the axial ends, that is, on the cylinder base and on the forward end of the piston, the pile being held in such a manner that the drive direction coincides with the axis of the vibration cylinder.

Abstract: A low velocity, high mass ram is connected to the cutting tool. The cutting tool has an array of impact forward and side buttons or bars which form chip-forming spaces there between. The side buttons or bars advantageously cut a gage in the slot. A method of slot kerfing which cuts the kerf on an angle.

Abstract: The reciprocably supported member is accompanied by means whereby its stroke can be relocated so that it can be used to drive its support if desired, even while it is simultaneously driving a tool or the like connected therewith. Also, the member may have its own onboard drive means; as well as onboard means for removing any debris that the tool generates. The drive means may comprise a combustion engine and the debris removal means may use the combustion gases of the engine as a flush medium for the same. Ordinarily, the flush medium is discharged adjacent the outer periphery of the working face of the tool and removes the debris through apertures adjacent the outer peripheral edge of the same. Other features are also described.

Abstract: A fastener driving tool includes a housing assembly with a nosepiece assembly defining a drive track. A driving mechanism is housed within the housing assembly to drive a fastener through the drive track and into a workpiece in response to a trigger. The tool includes a safety trip assembly which includes a trigger enabling portion and a workpiece engaging portion and is movable between an extended disabling position and a retracted enabling position. The safety trip assembly is biased toward the extended position and is moved toward the retracted position by engagement between the workpiece and the workpiece engaging member. The workpiece engaging portion is movable to permit adjustment of a length of the safety trip assembly. The safety trip assembly includes a coupling mechanism including a fixed locking structure formed on an exterior portion of the workpiece engaging portion and a manually operable locking mechanism.