Drive center with guard
AssigneeBig Tree Tools, LLC
InventorsJon Siegel, Grinnell More
Life of this patent
Estimating the term…
Abstract
A drive center constituting a machine tool accessory being used on a lathe for holding workpieces that are mounted between the headstock and the tailstock (between centers). The drive center includes a head having an adjustable spring-loaded center point and a number of removable, adjustable spurs that are capable of penetrating a workpiece sufficiently to provide torque for the turning process. The head is attached to a shank with a standard taper to fit the spindle of a lathe. A cylindrical guard is supported coaxially by the external surface of the head so that the guard radially encircles the head and the spurs but is able to slide axially and rotationally with respect to the head. A spring causes the guard to extend axially beyond the spurs except when pushed back by the workpiece.
Claims19
A drive center for use with a lathe comprising a headstock and a tailstock, the drive center comprising:
- a head having a leading face and an exterior surface, and the leading face of the head supporting a plurality of spurs and a center point;
- a shank being integrally connected with a trailing end of the head and having a remote end that is spaced from the head;
- and the center point, the shank and the head defining a rotational axis of the drive center;
- a cylindrical guard being coaxially supported by the exterior surface of the head such that the guard encases the head, and the guard being axially slidable along the exterior surface of the head between an extended position and a retracted position;
- and
- a spring being arranged around the head and biasing the guard into the extended position in which a leading portion of the guard projects past the leading face of the head and the spurs but not the center point, and the guard, when in the retracted position, encloses the spurs while still facilitating engagement between the spurs and a workpiece.
A drive center for use with a lathe having a headstock and a tailstock, the drive center comprising:
- a head having a leading face and an external surface having a flange located at an axial end of the head opposite from the leading face, the head supporting a center point and at least two spurs which extend axially beyond the leading face of the head;
- a shank being fixed to a trailing end of the head that is axially opposite the leading face of the head, the shank and the head defining a rotational axis of the drive center;
- a cylindrical guard being coaxially supported by the external surface of the head such that the guard radially encircles the head, the guard having a cylindrical inner surface that is directly supported on the external surface of the head and the flange such that the guard is axially movable with respect to the head, the flange axially engages a retainer that is seated in the guard to limit axial movement of the guard with respect to the head, the guard being in a fully extended position when the flange engages the retainer;
- a first spring being radially located between the inner surface of the guard and the external surface of the head, the first spring contacting the flange and the guard so as to continually bias the guard axially toward the fully extended position in which the guard extends axially beyond the leading face of the head and the at least two spurs.
A drive center for use with a lathe having a headstock and a tailstock, the drive center comprising:
- a cylindrical head having a leading face, a trailing end and an external surface, a flange radially extending from the external surface at the trailing end of the head, the head having a plurality of bores which receive and support a center point and at least two spurs such that the center point and the at least two spurs extend axially beyond the leading face of the head;
- a shank being connected to the trailing end of the head and having an axially opposite remote end, the shank and the head defining a rotational axis of the drive center;
- a cylindrical guard being coaxially supported by the external surface of the head such that the guard radially encircles the head, the guard having a radially inner surface that extends axially from a leading surface of the guard to a tail end of the guard, the inner surface comprising a sliding surface and a trailing surface that has greater diameter than the sliding surface such that a shoulder is formed therebetween, the trailing surface having an annular groove located adjacent the tail end of the guard, the sliding surface contacts the external surface of the head and the flange contacts the trailing surface of the guard such that the guard is axially slidable along the rotational axis with respect to the head, an annular gap being formed axially between the flange and the shoulder of the inner surface of the guard;
- a retaining ring being received within the annular groove, the flange of the head abuts the retaining ring to limit axial sliding of the guard in a forward direction toward the leading face of the head;
- and
- a first spring being located within the gap and abutting the flange and the shoulder of the inner surface of the guard, the first spring exerting a force on the guard in the forward direction toward the leading face of the head, such that a portion of the guard extends axially beyond the leading face of the head and radially encircles the at least two spurs, the guard being axially slidable against the force of the first spring in a reverse direction toward the remote end of the shank.
Dependencies are inferred from the claim text.