Abstract: A vibration drill unit capable of obtaining an intensive drilling force. The vibration drill unit includes a first ratchet, anon-rotatable second ratchet having a claw engageable with the claw of the first ratchet, and a main body frame for accommodating a motor, a spindle, the first ratchet and the second ratchet. The respective claws of the first ratchet and the second ratchet include the first inclined surfaces formed so as to be engaged in the rotation direction by rotations of the first ratchet and so as to be separated from each other, the second inclined surfaces having greater inclination in the reversed direction than the first inclined surfaces, top parts that link the upper parts of both inclined surfaces to each other, and flat parts that link the bottom parts of both inclined surfaces to each other.

Abstract: A compact drilling system capable of improving working efficiency. The drilling system includes a drilling machine and a compressor. A control circuit controls performances of a drill motor in the drilling machine and an air compression motor in the compressor based on the detection result of a pressure sensor that detects a pressure within an air tank provided in the compressor. When one of the motors is activated, the other motor is not allowed to be operated and only when the drill motor is activated, compressed air is supplied from the air tank to the drilling machine. An electrical socket is provided in the compressor. A power cord extending from the drilling machine can be connected to the socket.

Abstract: An impact hammer drill capable of performing drilling operation at a high speed with low noise and without requiring a large thrust. The drill includes a main shaft rotatable by an output shaft of a motor, and a spindle having an impact-receiving section and disposed over the main shaft slidably in its axial direction and rotatable together with the rotation of the main shaft. A piston is reciprocatingly slidably disposed over the main shaft for impacting against the impact-receiving section. A piston drive unit is disposed for driving the piston with a compressed fluid. A compressed fluid supplying unit is disposed for supplying the compressed fluid to the piston drive unit. A drill bit is attachable to the spindle. When performing drilling operation, the drill bit is imparted with a combined rotational motion and the reciprocal impact motion.

Abstract: A light weight saber saw with reduced numbers of mechanical components and capable of preventing liquid and dust from entering interior of a housing. A plunger reciprocates only in its axial direction in conformity with a longitudinal direction of the housing. A blade holding portion is pivotally movably connected to a front end of the plunger. The blade holding portion includes a plunger chip through which a rear end of a blade is insertable, and a blade holder covering the plunger chip. The blade holder has a track side corresponding to tooth side of the blade, and a track having an inclined track surface is provided at the track side. The housing rotatably supports a roller in rolling contact with the track surface. When the blade is retractingly moved into the housing, the blade holding portion and the blade are pivotally moved totether toward a workpiece by the contact between the roller and the track surface.

Abstract: A vibration drill unit capable of obtaining an intensive drilling force. The vibration drill unit includes a first ratchet, anon-rotatable second ratchet having a claw engageable with the claw of the first ratchet, and a main body frame for accommodating a motor, a spindle, the first ratchet and the second ratchet. The respective claws of the first ratchet and the second ratchet include the first inclined surfaces formed so as to be engaged in the rotation direction by rotations of the first ratchet and so as to be separated from each other, the second inclined surfaces 34a-2 and 35a-2 having greater inclination in the reversed direction than the first inclined surfaces, top parts that link the upper parts of both inclined surfaces to each other, and flat parts that link the bottom parts of both inclined surfaces to each other.

Abstract: A compact drilling system capable of improving working efficiency. The drilling system includes a drilling machine and a compressor. A control circuit controls performances of a drill motor in the drilling machine and an air compression motor in the compressor based on the detection result of a pressure sensor that detects a pressure within an air tank provided in the compressor. When one of the motors is activated, the other motor is not allowed to be operated and only when the drill motor is activated, compressed air is supplied from the air tank to the drilling machine. An electrical socket is provided in the compressor. A power cord extending from the drilling machine can be connected to the socket.

Abstract: A drilling machine capable of performing drilling operation at a high speed with low noise and without requiring a large thrust. The drilling machine includes a main shaft rotatable by an output shaft of a motor, and a spindle having an impact-receiving section and disposed over the main shaft slidably in its axial direction and rotatable together with the rotation of the main shaft. A piston 25 is reciprocatingly slidably disposed over the main shaft for impacting against the impact-receiving section. A piston drive unit is disposed for driving the piston with a compressed fluid. A compressed fluid supplying unit is disposed for supplying the compressed fluid to the piston drive unit. A drill bit is attachable to the spindle. When performing drilling operation, the drill bit is imparted with a combined rotational motion and the reciprocal impact motion.

Abstract: A light weight saber saw with reduced numbers of mechanical components and capable of preventing liquid and dust from entering interior of a housing. A plunger reciprocates only in its axial direction in conformity with a longitudinal direction of the housing. A blade holding portion is pivotally movably connected to a front end of the plunger. The blade holding portion includes a plunger chip through which a rear end of a blade is insertable, and a blade holder covering the plunger chip. The blade holder has a track side corresponding to tooth side of the blade, and a track having an inclined track surface is provided at the track side. The housing rotatably supports a roller in rolling contact with the track surface. When the blade is retractingly moved into the housing, the blade holding portion and the blade are pivotally moved totether toward a workpiece by the contact between the roller and the track surface.

Abstract: A first switching member, having a claw portion engageable with a claw portion of a first gear, is slidably mounted on a crank shaft without causing any relative rotation therebetween. A first urging member resiliently urges the first switching member so that the claw portion of the first switching member is engaged with the claw portion of the first gear. A second switching member, having a claw portion engageable with a claw portion of a second gear, is slidably mounted on an intermediate shaft without causing any relative rotation therebetween. A second urging member resiliently urges the second switching member so that the claw portion of the second switching member is engaged with the claw portion of the second gear.

Abstract: A first switching member, having a claw portion engageable with a claw portion of a first gear, is slidably mounted on a crank shaft without causing any relative rotation therebetween. A first urging member resiliently urges the first switching member so that the claw portion of the first switching member is engaged with the claw portion of the first gear. A second switching member, having a claw portion engageable with a claw portion of a second gear, is slidably mounted on an intermediate shaft without causing any relative rotation therebetween. A second urging member resiliently urges the second switching member so that the claw portion of the second switching member is engaged with the claw portion of the second gear.

Abstract: A second pinion is rotatably supported around an intermediate shaft and slidable in an axial direction of the intermediate shaft. A pinion sleeve is fixed to the intermediate shaft. A first clutch mechanism selectively engages and disengages the second pinion with and from the pinion sleeve to selectively transmit and interrupt a rotational force of a motor to a tool attached on a front end of a hammer drill. A sleeve is supported around the intermediate shaft so as not to be rotatable about the intermediate shaft but slidable in the axial direction of the intermediate shaft. A motion converting member is rotatably supported around the intermediate shaft. The motion converting member converts the rotational force of the motor into the percussion force. A second clutch mechanism selectively engages and disengages the motion converting member with and from the sleeve to selectively transmit and interrupt the percussion force to the tool.

Abstract: A power-driven impact drill includes a spindle extending at a right angle to the axis of rotation of a drill bit, a rotational first hammer slidably mounted on the spindle for co-rotation therewith, and a reciprocal second hammer slidably disposed in front of the drill bit. When the rotation of the first hammer is arrested by the second hammer, the first hammer is caused by a cam mechanism to retract along the spindle in a direction away from the second hammer against the force of a first hammer spring. Upon disengagement with the second hammer, the first hammer is permitted by the cam mechanism to slide back into engagement with the second hammer under the force of the first hammer spring while it is rotated by the spindle. In this instance, the angular velocity of the first hammer received by the spindle is enhanced by the force stored in the compressed first hammer spring so that a large impact power is imposed to the rotating drill via the second hammer without substantial loss.