An efficiency-enhanced resonant system is provided with a backing mass connected to a linear vibrator, a parasitic mass connected to the linear vibrator, a positioning spring, a connecting device, and external biasing springs. The linear vibrator provides vibrating force to the parasitic mass which is connected to the connecting device, grasping a working implement. The use of separate positioning spring and external biasing springs accommodates a tuned system that balances the reduction in backing mass movement, avoids backing mass resonance within the working range of frequencies, and maintains a minimized linear vibrator stroke within the optimal range for one-dimensional implements within desired frequency ranges. The linear vibrator provides vibration that manifests as a frequency range of the natural frequency of the combined assembly of the parasitic mass, positioning spring, external biasing springs, connecting device, and implement, so that the resonant system efficiently performs work with minimized wasted energy.

A vibratory compactor is provided. The vibratory compactor may include a compactor plate, a frame coupled to the compactor plate, wherein the frame may include an inner space and a housing. The frame may include a plurality of mounting brackets coupled between a first side member and a second side member of the frame. The vibratory compactor may include a vibration generation device coupled to the compactor plate within the inner space of the frame. The vibratory compactor may include a plurality of isolators, each isolator coupled to one mounting bracket of the plurality of mounting brackets. The housing may be coupled to the plurality of isolators, wherein the housing may include couplers removably coupled to a top surface of the housing. The couplers may be configured for coupling the vibratory compactor to an excavator type vehicle.

A device and a method for generating percussive pulses or vibrations for a construction machine, in which a piston is reversibly reciprocated in a working space in a housing between a first reversal point and a second reversal point, wherein, for the purpose of generating the percussive pulses or vibrations, the piston is set into a reversible movement by a pressure fluid and the pressure fluid is led into and out of the working space in the region of the first reversal point and the second reversal point. The position of the piston is detected by way of a sensor, in that depending on the detected position of the piston a control unit controls at least one controllable valve, through which pressure fluid is led into and/or out of the working space, wherein by the control unit the movement of the piston is controlled.

A device and a method for generating percussive pulses or vibrations for a construction machine, in which a piston is reversibly reciprocated in a working space in a housing between a first reversal point and a second reversal point, wherein, for the purpose of generating the percussive pulses or vibrations, the piston is set into a reversible movement by a pressure fluid and the pressure fluid is led into and out of the working space in the region of the first reversal point and the second reversal point. The position of the piston is detected by way of a sensor, in that depending on the detected position of the piston a control unit controls at least one controllable valve, through which pressure fluid is led into and/or out of the working space, wherein by the control unit the movement of the piston is controlled.

A roller tube concrete finishing machine includes retractable vibration gangs that can be selectively immersed within wet concrete and then retracted with parallelogram linkage. Spaced-apart, drive parallel rollers are journaled between frame ends for supporting and propelling the machine upon and between parallel form rails. A front roller provide a strike-off function. The vibration gangs are deployed by a retractable, parallelogram linkage that moves them forwardly and downwardly for operation, or which retracts the vibrators inwardly and upwardly relative to the frame. When the vibrators are retracted, the are withdrawn upwardly from the concrete and retracted rearwardly towards the machine front to reduce machine dimensions. Substantial retraction of the vibrators prevents subsequent interference with the rebar below. Vibrator retraction reduces overall machine dimensions for clearance and shipping purposes, with gang vibration arrays nested upwardly and inwardly proximate the front of the machine.

An agitator for vibrating a drill string includes an agitator housing, a rotor and an agitation mass. The drill string has a central axis. The rotor is coupled to the agitator housing and being rotatable about an agitator axis. The agitation mass is coupled to the rotor and is rotatable about the agitator axis. During rotation, a center of mass of the agitation mass is spaced apart from the agitator axis to cause deflection of the agitator axis relative to the central axis to produce vibration in the drill string.

A pile driving adapter includes an upper attachment portion for selectively attaching the adapter to a drill head and a lower housing portion including at least a first outer wall. The pile driving adapter further includes at least one actuator including a first portion slidably mounted to the lower housing portion and a second portion configured to expand from the first portion in a direction perpendicular to the first outer wall. The first portion may be slidably mounted to the lower housing portion via a sliding mount, and the lower housing portion may include at least one elongate slot for receiving at least a portion of the sliding mount. The pile driving adapter advantageously couples the drill head and the member to be driven so as to reliably transfer sonic energy.

A pile driving adapter includes an upper attachment portion for selectively attaching the adapter to a drill head and a lower housing portion including at least a first outer wall. The pile driving adapter further includes at least one actuator including a first portion slidably mounted to the lower housing portion and a second portion configured to expand from the first portion in a direction perpendicular to the first outer wall. The first portion may be slidably mounted to the lower housing portion via a sliding mount, and the lower housing portion may include at least one elongate slot for receiving at least a portion of the sliding mount. The pile driving adapter advantageously couples the drill head and the member to be driven so as to reliably transfer sonic energy.

In one embodiment, a centrifugal force generating device comprises a first hydraulic rotor, a second hydraulic rotor, and one or more hydraulic control valves. The first hydraulic rotor comprises a first mass and is configured to rotationally drive the first mass around a first axis of rotation using a first flow of hydraulic fluid through the first hydraulic rotor. The second hydraulic rotor comprises a second mass and is configured to rotationally drive the second mass around a second axis of rotation using a second flow of hydraulic fluid through the second hydraulic rotor. The one or more hydraulic control valves are configured to control the first flow of hydraulic fluid through the first hydraulic rotor and the second flow of hydraulic fluid through the second hydraulic rotor.

Provided in a tamping unit for tamping a track are squeezing drives (14) for a squeezing motion of tamping tines. In a hydraulic cylinder (19)having a squeezing piston (17) with a piston rod (18)of the squeezing drive (14), a first pressure chamber (20) for producing the squeezing motion (8) is provided. Additionally arranged is a second pressure chamber (21) for producing an opening motion directed opposite to the squeezing motion, and a third pressure chamber (22) provided for producing vibrations.