A compactor includes a plate, a shaft rotatably supported upon the plate, an electric motor configured to cause rotation of the shaft, and an eccentric mass arranged to rotate on the shaft, causing the plate to vibrate in response to rotation of the eccentric mass. The eccentric mass is configured to translate along the shaft.

A stand-alone motor unit includes a base having a first side and a second side adjacent the first side, an electric motor arranged in the base and including an output shaft, a power take-off shaft receiving torque from the motor and protruding from the second side of the base, a battery pack, and a battery module removably coupled to the base. The battery module includes a side wall and a battery receptacle for receiving the battery pack for providing power to the motor when the battery module is coupled to the base. The battery module is configured to be coupled to the base in a first position, in which the side wall of the battery module is parallel with the second side of the base, and in a second position, in which the side wall is perpendicular to the second side of the base.

A rammer includes: an outer cylinder (31); an inner cylinder (32) slidably contacted with an inside of the outer cylinder (31); a slider (33) connected to a connecting rod (14) and slidably provided in the inner cylinder (32); a first coil spring (34) housed in the upper part of the inner cylinder (32); and a second coil spring (35) housed in the lower part of the inner cylinder (32), wherein the slider (33) is disposed between the first coil spring (34) and the second coil spring (35), wherein a crank shaft has a rotational axis disposed orthogonally to the moving direction, and the first coil spring (34) and the second coil spring (35) have respectively different winding directions to each other.

A rammer includes: an outer cylinder (31); an inner cylinder (32) slidably contacted with an inside of the outer cylinder (31); a slider (33) connected to a connecting rod (14) and slidably provided in the inner cylinder (32); a first coil spring (34) housed in the upper part of the inner cylinder (32); and a second coil spring (35) housed in the lower part of the inner cylinder (32), wherein the slider (33) is disposed between the first coil spring (34) and the second coil spring (35), wherein a crank shaft has a rotational axis disposed orthogonally to the moving direction, and the first coil spring (34) and the second coil spring (35) have respectively different winding directions to each other.

A rammer includes: an engine; a reciprocating mechanism (3) including a crank shaft (13) and a connecting rod (14), and configure to convert a rotational force of the engine into a reciprocatory force; a leg part disposed in a forward inclined position in a traveling direction and configure to be moved up and down by the connecting rod (14); and a compacting plate disposed on a bottom end of the leg part. The crank shaft (13) is disposed orthogonally to the traveling direction. The reciprocating mechanism (3) includes a belt reduction mechanism (16) and a gear reduction mechanism (17).

A rammer includes: an engine; a reciprocating mechanism (3) including a crank shaft (13) and a connecting rod (14), and configure to convert a rotational force of the engine into a reciprocatory force; a leg part disposed in a forward inclined position in a traveling direction and configure to be moved up and down by the connecting rod (14); and a compacting plate disposed on a bottom end of the leg part. The crank shaft (13) is disposed orthogonally to the traveling direction. The reciprocating mechanism (3) includes a belt reduction mechanism (16) and a gear reduction mechanism (17).

A hand-guided ground compaction machine, in particular a vibratory tamper or vibration plate compactor, having a superstructure, a drive device arranged on the superstructure and having at least one drive shaft, a substructure having a compaction plate driven by the drive device, and a sensor device comprising an accelerometer for determining the ground stiffness of a ground to be compacted, wherein the sensor device is supplied with electrical power, in particular solely, by a generator driven by the at least one drive shaft.

A hand-guided ground compaction machine, in particular a vibratory tamper or vibration plate compactor, having a superstructure, a drive device arranged on the superstructure and having at least one drive shaft, a substructure having a compaction plate driven by the drive device, and a sensor device comprising an accelerometer for determining the ground stiffness of a ground to be compacted, wherein the sensor device is supplied with electrical power, in particular solely, by a generator driven by the at least one drive shaft.

An apparatus for leveling a concrete screed having a frame and a screed head secured thereto includes a plurality of vertically adjustable leveling legs driven by a plurality of electrical actuators responsive to a command supplied by a user interface.

An apparatus for screeding concrete to produce a level finished surface includes a frame assembly having an integral screed head having at least one member for contacting said concrete, a leveling assembly secured to the frame assembly having a plurality of vertically adjustable leveling legs capable of extension and retraction and a plurality of wheels secured to the leveling legs, each capable of rotation around a vertical axis for steering.