A method for treating an interior weld joint located along an inner surface of a pipe includes the steps of: (a) advancing an internal grinder device within the pipe to the interior weld joint, wherein the internal grinder device includes a hollow housing that has a first open end and a first grinding implement that is disposed within the hollow housing and coupled thereto with a first biasing member; and (b) controllably rotating the hollow housing to at least a threshold speed at which time and under centrifugal force, the first grinding implement moves from an at rest retracted position to a deployed position in which the first grinding implement extends radially beyond the first open end for contacting and grinding the interior weld joint as the hollow housing and the first grinding implement are rotated.

A pipe spinning power drill accessory a stem, shaft, first knurled assembly, second knurled assembly, first state, and second state. The first knurled assembly and the second knurled assembly are each cylindrically shaped. The first knurled assembly is centrally affixed to the stem. The shaft is centrally affixed to the first knurled assembly opposite the stem. The second knurled assembly is centrally affixed to the shaft opposite the first knurled assembly. The first knurled assembly and the second knurled assembly each selectively expand laterally. In the first state, the first knurled assembly and the second knurled assembly are each not laterally expanded. In the second state, at least one of the first knurled assembly and the second knurled assembly are laterally expanded. The stem is configured to be inserted into a chuck of a power drill. The stem is cross-sectionally hexagonally shaped and includes a region of decreased diameter.

A pipe spinning power drill accessory a stem, shaft, first knurled assembly, second knurled assembly, first state, and second state. The first knurled assembly and the second knurled assembly are each cylindrically shaped. The first knurled assembly is centrally affixed to the stem. The shaft is centrally affixed to the first knurled assembly opposite the stem. The second knurled assembly is centrally affixed to the shaft opposite the first knurled assembly. The first knurled assembly and the second knurled assembly each selectively expand laterally. In the first state, the first knurled assembly and the second knurled assembly are each not laterally expanded. In the second state, at least one of the first knurled assembly and the second knurled assembly are laterally expanded. The stem is configured to be inserted into a chuck of a power drill. The stem is cross-sectionally hexagonally shaped and includes a region of decreased diameter.

A cutting head operated by a centrifugal force according to an embodiment of the present invention includes: an external housing that is rotatable; an internal housing installed within the external housing so as to be able to advance and retreat in a diameter direction, advanced toward a cut surface of a workpiece positioned outside the external housing by a centrifugal force according to rotation of the external housing, and retreated in a direction that becomes distant from the cut surface by an elastic member while the centrifugal force disappears; and a cutting tool unit provided in the internal housing and processing a groove in the cut surface while being advanced and retreated by a micro advance and retreat member.

A method for treating an interior weld joint located along an inner surface of a pipe includes the steps of: (a) advancing an internal grinder device within the pipe to the interior weld joint, wherein the internal grinder device includes a hollow housing that has a first open end and a first grinding implement that is disposed within the hollow housing and coupled thereto with a first biasing member; and (b) controllably rotating the hollow housing to at least a threshold speed at which time and under centrifugal force, the first grinding implement moves from an at rest retracted position to a deployed position in which the first grinding implement extends radially beyond the first open end for contacting and grinding the interior weld joint as the hollow housing and the first grinding implement are rotated.

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 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.

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.

A cutting head operated by a centrifugal force according to an embodiment of the present invention includes: an external housing that is rotatable; an internal housing installed within the external housing so as to be able to advance and retreat in a diameter direction, advanced toward a cut surface of a workpiece positioned outside the external housing by a centrifugal force according to rotation of the external housing, and retreated in a direction that becomes distant from the cut surface by an elastic member while the centrifugal force disappears; and a cutting tool unit provided in the internal housing and processing a groove in the cut surface while being advanced and retreated by a micro advance and retreat member.

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.