A quick clamping device for a portable power tool includes at least one rotatably drivable output shaft, at least one clamping unit, at least one operating unit, and at least one uncoupling unit. The clamping unit, for tool-free fastening of an insert tool unit to the output shaft, includes at least one movably mounted clamping element for applying clamping force to the insert tool unit in a clamping position of the clamping element. The operating unit is configured to move the clamping element into the clamping position and/or into a release position of the clamping element. In the release position, the insert tool unit can be removed from the clamping unit. The at least one uncoupling unit is configured to uncouple the operating unit from the clamping unit in accordance with the rotational speed of the output shaft.

A cutting tool holding mechanism for detachably holding a cutting tool includes: a collet chuck configured to clamp and unclamp the cutting tool; a piston disposed deeper on the proximal side of the spindle than the collet chuck and configured to urge the collet chuck by the pressure of a fluid supplied from the proximal side of the spindle in the direction from the proximal side toward the distal end side of the spindle so that the collet chuck unclamps the cutting tool; a spool valve provided in the piston and configured to open thanks to centrifugal force at the time when the spindle is turned, so as to supply the fluid fed from the spindle side to the cutting tool.

A fixture for machining wheel outer rim without trace includes a positioning and clamping portion and a flexible support portion. A base is fixed on a bottom plate, and a screw is configured to compress an expanding pressure plate during being tightened so that the outer circumference of an expanding sleeve expands a center hole of a wheel; and the positioning columns are inserted into bolt holes of the wheel. A lower pressure plate is fixed on the base, and limiting columns and an upper pressure plate are installed on the lower pressure plate, with steel balls and rubber strip being enclosed in a space formed by the lower pressure plate and the upper pressure plate. The fixture meets the requirement for machining the wheel outer rim without trace, has the characteristics of simple structure, convenient manufacture, stable performance and precision, and meets the requirements of automatic production.

A diameter expansion drill bit used to expand the diameter of a part of a prepared hole bored in a frame by grinding includes: a cutting-blade portion that has a plurality of separate cutting-blade portions; a cutting-blade holding portion that slidably holds the plurality of separate cutting-blade portions in a radial direction; and a shank portion that supports the cutting-blade holding portion. The plurality of separate cutting-blade portions is arranged in a peripheral direction and arranged over a plurality of stages in a shaft direction, and the plurality of separate cutting-blade portions of the respective stages is caused to slide by a centrifugal force resulting from rotation so as to spread to an outside in the radial direction with respect to the cutting-blade holding portion.

An actuatable boring bar is configured to place a cutting insert cartridge received onto the boring bar in a cutting position when the centrifugal force generated by the rotation of the boring bar about the rotation axis reaches a centrifugal force threshold and in a non-cutting position when the centrifugal force generated by the rotation of the boring bar about the rotation axis is below the centrifugal force threshold. The boring bar is further configured so that the cutting insert cartridge can be set-up onto the boring bar in the cutting position.

A cutting tool holding mechanism for detachably holding a cutting tool includes: a collet chuck configured to clamp and unclamp the cutting tool; a piston disposed deeper on the proximal side of the spindle than the collet chuck and configured to urge the collet chuck by the pressure of a fluid supplied from the proximal side of the spindle in the direction from the proximal side toward the distal end side of the spindle so that the collet chuck unclamps the cutting tool; a spool valve provided in the piston and configured to open thanks to centrifugal force at the time when the spindle is turned, so as to supply the fluid fed from the spindle side to the cutting tool.

A tool accessory used to apply different volumes of a cutting fluid to the tap under CNC control by causing the machine to undergo different pump cycles in which the rotational speed of the tool is increased above the tapping rotated and then quickly returned to the tapping rotation. The tool includes a tapping head, a reservoir filled with cutting fluid, a centrifugal force-reactive pump and at least two discharge nozzles. The pump includes a plurality of biased piston springs that are forced outward and store centripetal force when the tool is rotated at speeds above normal tapping speed. When the rotational speed of the tool is reduced, the piston springs overcome the centrifugal forces and force cutting fluid through the discharge nozzles. The volume of cutting fluid discharged is controlled by adjusting the viscosity of the cutting fluid, the tool's maximum speed, by using different size discharge nozzles, and by using different pump cycles.

The cleaning device is for cleaning a pipe before lining of the pipe and for removing a collapsed liner inside the pipe. The cleaning device has a connector for a drive shaft, a body rotatable around a rotation axis with the drive shaft and grinding cutters pivotally attached to the body by pins. The cutters have cutting edges provided on outer periphery of the cleaning device and the pivotal connection to the body allows for the cutters to turn and increase the diameter of the cleaning device until the cutters face an obstacle.

A diameter expansion drill bit used to expand the diameter of a part of a prepared hole bored in a frame by grinding includes: a cutting-blade portion that has a plurality of separate cutting-blade portions; a cutting-blade holding portion that slidably holds the plurality of separate cutting-blade portions in a radial direction; and a shank portion that supports the cutting-blade holding portion. The plurality of separate cutting-blade portions is arranged in a peripheral direction and arranged over a plurality of stages in a shaft direction, and the plurality of separate cutting-blade portions of the respective stages is caused to slide by a centrifugal force resulting from rotation so as to spread to an outside in the radial direction with respect to the cutting-blade holding portion.

To provide a method for forming an anchor hole and a diameter expansion device by which a centrifugal force can be appropriately adjusted when a cutting-blade portion is moved in a radial direction by the centrifugal force to grind a diameter expansion portion. In a method for forming an anchor hole for a post-installed anchor in which a diameter expansion drill bit is inserted and rotated in a prepared-hole portion bored in a concrete fixing body and a cutting-blade portion of the diameter expansion drill bit is moved in a radial direction by a centrifugal force to grind a part of the prepared-hole portion to form a diameter expansion portion, the minimum value of the centrifugal force applied to grind the diameter expansion portion is 0.75 N and preferably 1.1 N.