Self-tapping bush-shaped screwed insert
AssigneePama Reiter Stefan
InventorStefan Reiter
Life of this patent
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Abstract
A thread-cutting screwed dowel has an essentially cylindrical, sleevelike dowel body with an axial bore and with a load engagement device disposed in the interior of the dowel body, for example with a female thread. On its outer face, the dowel body is equipped with at least one cutting edge, which extends helically along a majority of the outer face of the dowel body and protrudes radially past it. The helical cutting edge is embodied as a primary cutting edge and wraps around the dowel body over its length in at least three windings. Besides the load engagement device, an additional engagement is provided for transmitting a torque in the interior of the dowel body.
Claims22
Screw-in dowel, comprising:
- an essentially cylindrical dowel body, which has an axial bore;
- load engagement means, disposed in the axial bore;
- at least one cutting edge on an outer face, which extends helically along a majority of the outer face of the dowel body and protrudes radially past it, the cutting edge being a primary cutting edge, which over its length wraps around said dowel body in at least three windings;
- engagement means for transmitting a torque to the dowel body, the engagement means being disposed in an interior of the dowel body;
- and
- two auxiliary cutting edges that extend helically along the dowel body, each end of the auxiliary cutting edges extending from a thread onset, on a front region of the dowel body in terms of the setting direction, helically along the dowel body, protruding radially past the dowel body, and wrapping around it in at least 1.5 windings, wherein the primary cutting edge and the auxiliary cutting edges, on the front region of the dowel body in terms of the setting direction, each have thread onset regions, at which their radial protrusion past the outer face of the dowel body decreases essentially to zero, and that the thread onset regions are disposed at an angular spacing of approximately 120° from one another on a same circumferential circle of the dowel body.
Screw-in dowel, comprising:
- an essentially cylindrical dowel body, which has an axial bore;
- load engagement means, disposed in the axial bore;
- at least one cutting edge on an outer face, which extends helically along a majority of the outer face of the dowel body and protrudes radially past it, the cutting edge being a primary cutting edge, which over its length wraps around said dowel body in at least three windings;
- engagement means for transmitting a torque to the dowel body, the engagement means being disposed in an interior of the dowel body;
- and
- two auxiliary cutting edges that extend helically along the dowel body, each end of the auxiliary cutting edges extending from a thread onset, on a front region of the dowel body in terms of the setting direction, helically along the dowel body, protruding radially past the dowel body, and wrapping around it in at least 1.5 windings, wherein the dowel body has a rearward end region which widens, toward a rear face end, to an outside diameter which does not exceed a maximum outside diameter, measured across the windings of the primary cutting edge.
Dependencies are inferred from the claim text.