A driver capable of suppressing increase in a load torque of a motor when a striking mechanism is moved by the torque of the motor against a force of a first moving mechanism is provided. The driver includes a striking mechanism 12 movable in a first direction B1 and a second direction B2 opposite to the first direction B1 and a first moving mechanism configured to move the striking mechanism 12 in the first direction B1 to strike a fastener, and the driver further includes a motor, a second moving mechanism 45 rotated by the torque of the motor and configured to move the striking mechanism 12 in the second direction against a force of the first moving mechanism, and torque suppression mechanisms 45A to 45H configured to suppress increase in the torque of the motor when the striking mechanism 12 is moved in the second direction B2.

A method of retaining a hammer tool in the front head of a powercell assembly of a hammer assembly includes biasing a hammer tool retaining pin such that a portion of the tool retaining pin extends into a tool receiving bore of the front head of the powercell assembly, holding a hammer tool in the tool receiving bore of the front head of the powercell assembly via the tool retaining pin, and releasing the hammer tool remotely from the hammer assembly.

An impact tool includes a tool-accessory holding part, a body and a first hammering member. The tool-accessory holding part has a through hole extending in a hammering-axis direction and is configured to hold the tool accessory inserted into the through hole to be movable in the hammering-axis direction. The body is connected to the tool-accessory holding part in the hammering-axis direction and has an internal space communicating with the through hole. The first hammering member is linearly movable in the hammering-axis direction and configured to drive the tool accessory in the hammering-axis direction by colliding with the tool accessory. The tool-accessory holding part and the body are connected in the hammering-axis direction via a first elastic element to be movable relative to each other. A second elastic element is interposed between the first hammering member and the body in a radial direction with respect to the hammering axis.

A hydraulic, pneumatic, gasoline, diesel, or electric tool may include a spindle that is adapted for rotational movement. A swing arm may be coupled to the spindle such that rotational motion of the spindle is transferred to the swing arm. The swing arm makes contact with a piston such that the rotational motion causes the piston to move along a linear path. The piston may interact with an energy storage medium when the swing arm moves the piston in the first direction, causing energy to be stored in the energy storage medium. As the swing arm continues to rotate, the swing arm may lose contact with the piston, thus allowing the energy storage medium to urge the piston in a second direction opposite the first direction to strike an anvil. The swing arm may be a multiple roller swing arm. The energy storage medium may be a compound spring assembly.

A power tool, such as a rotary hammer or hammer drill, includes a first housing that contains a motor and a drive mechanism for linearly reciprocally driving a tool accessory, and a second housing that includes a handle, a first portion and a second portion. At least one elastic element connects the first and second housings such that the handle is biased away from the first housing. A first set of sliding contact surfaces is defined on or connected to the first housing and the first portion of the second housing. A second set of sliding contact surfaces is defined on or connected to the first housing and the second portion of the second housing. The first and second sets of sliding contact surfaces are located on opposite sides of the motor such that the rotational axis of the motor intersects the first and second sets of sliding contact surfaces.

A hand tool device has a tool spindle and a hammer mechanism which includes a hammer and at least one curve guide driving the hammer at least during a hammer drilling operation. The tool spindle has at least one bearing surface on which the hammer is movably supported in at least one operating state.

It is an object of the invention to provide rational structure for vibration proofing in hammering operation. A driving motor 110 and a striking mechanism 140 are provided in a first body element 101a, and a handle 109 and a battery mounting part 160 are provided in a second body element 101b. The first and second body elements 101a, 101b are moved with respect to each other via a biasing member 181 when vibration is caused by driving of the striking mechanism 140. Further, a first region 100a close to the striking mechanism 140 forms a long-distance moving region 200 in which the first and second body elements 101a, 101b move a longer distance in a longitudinal direction than in the second region 100b less close to the striking mechanism 140.

An impact tool for machining workpieces has an impact mechanism which is arranged in a housing and is suitable for transmitting an oscillating movement to a machining tip arranged in an axial direction, wherein the impact mechanism can be displaced against the housing between a lower stop point and an upper stop point in the axial direction, wherein a device for generating a constant or variable contact pressure of the machining tip is arranged between the housing and the impact mechanism, such that after a prestressing path of the impact mechanism from the lower stop point, the machining tip is additionally subjected to the contact pressure.

A hydraulic, pneumatic, gasoline, diesel, or electric tool may include a spindle that is adapted for rotational movement. A swing arm may be coupled to the spindle such that rotational motion of the spindle is transferred to the swing arm. The swing arm makes contact with a piston such that the rotational motion causes the piston to move along a linear path. The piston may interact with an energy storage medium when the swing arm moves the piston in the first direction, causing energy to be stored in the energy storage medium. As the swing arm continues to rotate, the swing arm may lose contact with the piston, thus allowing the energy storage medium to urge the piston in a second direction opposite the first direction to strike an anvil. The swing arm may be a multiple roller swing arm. The energy storage medium may be a compound spring assembly.

A force-limiting and damping device has a body, a tapping element, and an elastic element. The body has a connecting segment and a holding segment. The connecting segment is formed on an end of the body and has a mounting hole. The holding segment is formed on the body opposite the connecting segment. The tapping element is connected to the body to move relative to the connecting segment. The elastic element is mounted between the tapping element and the connecting segment to abut against the tapping element and to enable the tapping element to move relative to the connecting segment. The structural relationship between the connecting segment, the tapping element, and the elastic element may provide a delayed rebound and damping effect to the reaction force, and the applied force is continuously transferred to a tapping object. This may reduce noise and the loss of energy.