Abstract: There is provided a tool for repair of damaged threads of screws, including a body (2) having a projecting portion (4) for accommodating a screw to be repaired and having two recessed major surfaces; a cutting blade (6), having a rear end hingedly articulated to the body (2), and a front end in the shape of a cutting face (46) substantially fitting the type of thread to be repaired; a guide blade (7) having a rear end hingedly articulated to the body (2), and a front end substantially fitting the type of thread to be repaired, the guide blade projecting beyond the cutting face of the cutting blade, and; means (10, 12, 14) to alter the distance between the front ends and the projecting body portion (4) to accommodate screws of different diameters.

Abstract: A fast-acting die head that is particularly well-suited for use with small-size workpieces employs a set of chasers, each formed as a single piece and having a nose portion that provides two force-receiving surface elements. One of the surface elements is disposed to coact with a camming ring, which is moved axially thereover to close the chasers radially upon the workpiece; the other, underlying surface element receives the force of a spring-loaded plunger, which acts to thrust the associated chaser to an open position when the closing force of the camming ring is removed.

Abstract: An apparatus for machining an end of a tube clamped within the apparatus and including a tool head rotatable about the axis of the tube, a plurality of tool holders including tools arranged about the tool head and radially moveable with respect to the axis, a plurality of push rods uniformly positioned about the tool head and axially parallel to the axis including oblique toothing positioned about one end thereof and a frame connected to the push rods and being displaceable along the axis to provide axial movement to the push rods. A transmission device including toothing for engaging the toothing on the push rods is positioned between the tool holders and push rods for imparting radial movement to the tool holders and tools connected thereto based upon axial movement of the push rods.

Abstract: An adjustable die assembly having a ring structure with a clear central aperture for locating the ring structure along an axial length of a rod to have threads repaired or cut, and having a plurality of thread cutting chaser inserts connected to tool blocks which are slidable radially on said ring, each tool block connected to a threaded adjustment shaft, threaded into said ring for adjusting the radial position of each chaser insert. Alternatively, each threaded adjustment rod can be provided with a pinion gear, and a rim gear can be in mesh with each pinion gear, and a gear device can be provided for turning the rim gear to simultaneously adjust all chasers radially.

Abstract: Ketones are prepared by admixing at least one gem-dichloro compound with at least one acid such that the ketone wherein the keto-oxygen replaces the gem-dichloro group is formed. The reaction is exemplified by the reaction of 9,9-dichlorofluorene with an acid such that fluorenone is formed. This process has the advantage that no oxidizing agent is used.