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 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 pneumatic impact tool having a vibration reducing structure includes a handle with a bucket member and a directional control valve. A tube member including a cylindrical wall and a chamber is coupled with the bucket member. The chamber is divided into a front and a rear chamber portion by a hammer member. Gas may be guided into the front or the rear chamber portion by the directional control valve. A vent is disposed on the cylindrical wall. An exhaust channel which communicates with the front chamber portion and not communicates with the rear chamber portion is disposed on an outer peripheral surface of the hammer member. The hammer member is pushed to return if gas is guided into the front chamber portion. Gas in the front chamber portion is exhausted when the exhaust channel communicates with the vent.

Device (30) for making a hole in a golf green (100), comprising a cutting cylinder (4) with an open end being freely movable along the longitudinal direction; guide means (1) defining a weight path having a first endpoint and a second endpoint; a weight (5) guidedly movable along said weight path; a weight propulsion device, arranged to propel the weight reciprocally so that it strikes against the cutting cylinder; and a soil expulsion piston (9), movable inside said cutting cylinder.

The invention is characterised in that the device further comprises a piston driving mechanism, arranged to transfer a force from said weight is propulsion device to the piston to drive it towards said open end; and an expulsion activating mechanism, arranged to engage and disengage the piston driving mechanism in relation to the weight propulsion device.

The invention also relates to a method.

Device (30) for making a hole in a golf green (100), comprising a cutting cylinder (4) with an open end being freely movable along the longitudinal direction; guide means (1) defining a weight path having a first endpoint and a second endpoint; a weight (5) guidedly movable along said weight path; a weight propulsion device, arranged to propel the weight reciprocally so that it strikes against the cutting cylinder; and a soil expulsion piston (9), movable inside said cutting cylinder.

The invention is characterised in that the device further comprises a piston driving mechanism, arranged to transfer a force from said weight is propulsion device to the piston to drive it towards said open end; and an expulsion activating mechanism, arranged to engage and disengage the piston driving mechanism in relation to the weight propulsion device.

The invention also relates to a method.

The hydraulic rotary-percussive hammer drill includes a body; a shank; a striking piston configured to hit the shank; a stop piston configured to position the shank in a predetermined balanced position, the body and the stop piston delimiting a first control chamber permanently connected to a high-pressure fluid feed-in conduit and configured to urge the stop piston forwards, and a second control chamber configured to urge the stop piston forwards. The hydraulic rotary-percussive hammer drill comprises a fluidic communication channel opening into the second control chamber, configured to supply the second control chamber with high-pressure fluid and provided with a calibrated orifice.

The present application discloses a pneumatic chipping hammer, and relates to a pneumatic impact tool, which comprises a handle part, the handle part being a hollow member; a main power part, one end of the main power part being connected to the handle part, and principal axes of the handle part and the main power part forming a certain angle; and a chisel part, the chisel part being detachably connected to the other end of the main power part, wherein the direction of mounting the chisel part on the main power part can be changed. According to the pneumatic chipping hammer of the present application, the mounting direction of the chisel part on the main power part is changed by the locking member, and therefore the angle between the principal axes of the handle part and the main power part can be 5-85 degrees, so that a handle is inclined to further achieve different purposes and be suitable for people with different heights.

A hydraulic hammering device enables an auto-stroke mode and an idle strike prevention mode to coexist with a simple circuit configuration. A first control valve controls advancing and retracting movements of a piston and a second control valve select either the auto-stroke mode and the idle strike prevention mode. To the second control valve, a shared spool is slidably fitted and a mode selection means is disposed. When the mode selection means allows supply of pressurized oil to an auto-stroke setting portion of the shared spool and prohibits discharge of pressurized oil from an idle strike prevention setting portion, the auto-stroke mode is selected. When prohibiting supply of pressurized oil to the auto-stroke setting portion and allowing discharge of pressurized oil from the idle strike prevention setting portion, the idle strike prevention mode is selected.

A hydraulic hammering device enables an auto-stroke mode and an idle strike prevention mode to coexist with a simple circuit configuration. A first control valve controls advancing and retracting movements of a piston and a second control valve select either the auto-stroke mode and the idle strike prevention mode. To the second control valve, a shared spool is slidably fitted and a mode selection means is disposed. When the mode selection means allows supply of pressurized oil to an auto-stroke setting portion of the shared spool and prohibits discharge of pressurized oil from an idle strike prevention setting portion, the auto-stroke mode is selected. When prohibiting supply of pressurized oil to the auto-stroke setting portion and allowing discharge of pressurized oil from the idle strike prevention setting portion, the idle strike prevention mode is selected.

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.