Abstract: A hammer drill includes a motor; a spindle rotatingly driven by the motor and holding an output bit; a motion conversion member for converting rotational movement of the motor to reciprocating movement; a striker reciprocatingly driven by the motion conversion member for applying an axial striking force to the output bit; a striking-motion-releasing mechanism for releasing the striking force applying action exercised by the striker; and a tightening-torque adjusting clutch for interrupting the transfer of the rotational force to the output bit by increasing a load torque.

Abstract: A hammer drill includes a motor; a spindle rotatingly driven by the motor and holding an output bit; a motion conversion member for converting rotational movement of the motor to reciprocating movement; a striker reciprocatingly driven by the motion conversion member for applying an axial striking force to the output bit; a striking-motion-releasing mechanism for releasing the striking force applying action exercised by the striker; and a tightening-torque adjusting clutch for interrupting the transfer of the rotational force to the output bit by increasing a load torque.

Abstract: A hammer drill includes a motor; a spindle rotatingly driven by the motor and holding an output bit; a motion conversion member for converting rotational movement of the motor to reciprocating movement; a striker reciprocatingly driven by the motion conversion member for applying an axial striking force to the output bit; a striking-motion-releasing mechanism for releasing the striking force applying action exercised by the striker; and a tightening-torque adjusting clutch for interrupting the transfer of the rotational force to the output bit by increasing a load torque.

Abstract: A power impact tool includes a main body accommodating a chuck at a front end portion thereof; a clutch handle for setting a torque applied to the chuck; a grip including a base portion; a free end portion; and a reinforcing connecting portion connected to the front end portion of the main body at the back of the clutch handle and to the free end portion of the grip. The reinforcing connecting portion is disposed in front of the grip; and a part protruded most forward among the reinforcing connecting portion is located directly in front of the trigger switch disposed at the base portion of the grip. A part of the reinforcing connecting portion disposed behind the clutch handle retreats backward toward the free end portion of the grip.

Abstract: A power impact tool includes a main body accommodating a chuck at a front end portion thereof; a clutch handle for setting a torque applied to the chuck; a grip including a base portion; a free end portion; and a reinforcing connecting portion connected to the front end portion of the main body at the back of the clutch handle and to the free end portion of the grip. The reinforcing connecting portion is disposed in front of the grip; and a part protruded most forward among the reinforcing connecting portion is located directly in front of the trigger switch disposed at the base portion of the grip. A part of the reinforcing connecting portion disposed behind the clutch handle retreats backward toward the free end portion of the grip.

Abstract: A power impact tool adapter, for use in installing a bit to be used in a striking-motion-deactivated mode to a power impact tool, includes an SDS type shank portion to be held by a chuck; closed grooves to be mated with sprung balls to prevent the release of the bit; and slide grooves to be slidably mated with wedges applying a rotational force to the bit. An axial length of each slide groove is shorter than that of a slide groove of a standard SDS shank such that the end of the shank portion is prevented from contacting a striking member of the power impact tool which applies a striking force to the bit.

Abstract: A hammer drill includes a motor; a spindle rotatingly driven by the motor and holding an output bit; a motion conversion member for converting rotational movement of the motor to reciprocating movement; a striker reciprocatingly driven by the motion conversion member for applying an axial striking force to the output bit; a striking-motion-releasing mechanism for releasing the striking force applying action exercised by the striker; and a tightening-torque adjusting clutch for interrupting the transfer of the rotational force to the output bit by increasing a load torque.

Abstract: A saw tool comprises a housing for incorporating a driving device therein, a base attached to the housing, a driving arm connected to the driving device to effect a reciprocating orbital motion, and a saw blade attached to the driving arm and extending through a slit in the base. The saw blade has a first saw tooth section formed on a top end thereof for biting a workpiece and a second saw tooth section formed on one side thereof. A rectangular through-hole can be accurately and rapidly formed in a workpiece such as a plaster board or veneer board, etc., with this saw tool.

Abstract: A depth adjuster for a rotary tool such as a screwdriver having a tool bit projecting through a nose provided at the front end of the rotary tool. The depth adjustor comprises a locator sleeve mounted on the nose to project on the front end of the tool in such a manner as to surround the tool bit. The locator sleeve has an internal thread engaged with an external thread on the nose so as to be axially movable relative to the nose and the tool bit as the sleeve rotates about the nose. A lock ring is fitted on the nose to be rotatively fixed but axially movable relative thereto. The lock ring is biased towards the locator sleeve by a spring for locking engagement into the locator sleeve so as to rotatively fix the locator sleeve around the nose, whereby retaining the locator sleeve at a desired axial position relative to the nose.

Abstract: A keyless chuck for a rotary tool comprises a chuck body which is adapted to be coupled at its one end to a drive spindle of a drive source and coupled at the other end to a tool bit for establishing a driving connection from the drive source to the tool bit. Relatively rotatable to the chuck body is a sleeve ring which is operatively connected to a set of gripping jaws for tightening the gripping jaws on the tool bit upon being rotated in one direction and loosening the same upon being rotated in the opposite direction. A one-way clutch is provided to rotatively fix the sleeve ring to the chuck body when the chuck body is driven to rotate in the direction of turning the tool bit reversely.

Abstract: A keyless chuck for a rotary tool comprises a chuck body which is adapted to be coupled at its one end to a drive spindle of a drive source and coupled at the other end to a tool bit for establishing a driving connection from the drive source to the tool bit. Relatively rotatable to the chuck body is a handle ring which is operatively connected to a set of gripping jaws for tightening the gripping jaws on the tool bit upon being rotated in one direction and loosening the same upon being rotated in the opposite direction. The handle ring is disposed on the chuck body in such a manner as to coincide the rotating direction of the handle ring for tightening the gripping jaws with the reverse rotating direction of the chuck body for removing the tool bit from a workpiece.