Abstract: A surgical reamer, intended in particular for the shaping of the cotyloid cavity in the event of a replacement of a hip joint by total prosthesis. It is in the form of a hollow body of rotation equipped with fixing means (3, 4) for attachment to a reamer spindle in order to be driven in rotation. The hollow body (1) is supported by a bar (2) whose axis coincides at least approximately with the axis of rotation of the reamer and it extends essentially on one side of a plane containing the axis of the bar (2), at least part of the length of the rim of the hollow body forming a cutting edge (5). Such a reamer makes it possible to shape accurately a cavity of hemispherical or other shape, according to the shape of the hollow body.

Abstract: The reamer comprises a cap (1) and radial rods (2) which are arranged uniformly on the inside edge of the cap. These radial rods (2), which are at least three in number, join up at the center of the cap and are integral. The reamer spindle comprises a shank (3) on which there is fixed a reamer spindle head (5) which is equipped with a bayonet with locking means for the securing of the reamer. The securing catches (10) of the bayonet are intended to receive the radial rods (2) of the reamer. The center (14) of the bayonet is preferably recessed so that the latter can receive the radial rods (2) of the reamer and can serve as a cavity for retention of the bone substance which is removed.

Abstract: The quick-fastening device comprises only two parts separable during the fitting and removal of the bit, the first part being fixed to the tool and the second part being fixed to a motor-drive body. The axial locking and the rotational locking are ensured respectively by screwing and the engagement of two profiled ends of matching profiles.

Abstract: Feed apparatus for automatic lathes comprises a central section bar surrounded by one or more peripheral section bars, longitudinal grooves of arcuate cross-section in all the section bars matching and cooperating with each other to form longitudinal passages for guiding bar stock when the section bars are assembled. Linings may be placed in these passages to form tubes for guiding the bar stock, these tubes being very accurately positioned relative to the outer surface of the apparatus, which may be an outer tube into which the assembly of section bars is inserted. Hence the stock-guiding tubes can be more precisely positioned, and the apparatus can be produced at low cost because the section bars are inexpensive and assembly is simple. The apparatus is particularly suitable for feeding lathes on which objects made from bar stock of very different diameters has to be machined.