Patent ID: 8863863
Filing Date: 2014-10-21
Classification: B23B,Y10T

Abstract:
1. Undercutting tool for producing transverse grooves in a drilled hole, the undercutting tool having a geometric longitudinal axis having an axial direction and an inverse axial direction, comprising a shank, which has an upper support, which delimits the receiving region in the inverse axial direction, a lower support, which is spaced apart axially from the upper support, delimits the receiving region in the axial direction and, in particular, is disposed at the lower shank end, at least two spreading elements, realized as sleeve-type hollow bodies, which are disposed in an axially distributed manner in the receiving region, and which each encompass the receiving region, there being in each case, between the spreading elements and the receiving region of the shank, a radial play in a respective radial direction, perpendicularly in relation to the longitudinal axis, and the spreading elements each having at least one cutting tooth facing substantially radially outward in a respective radial direction, wherein the shank is realized in such a way, and the upper support and the lower support are disposed in such a way that the axial distance between the upper support and the lower support is reducible, by exerting an axial force, directed in the axial direction, upon the upper shank end, in particular in a resilient manner, the spreading elements are disposed in the receiving region so as to be secured against rotation and axially displaceable between the upper support and the lower support, the axial displaceability being delimited in the inverse axial direction by the upper support and in the axial direction by the lower support, the spreading elements each have an oblique upper end face that faces in the inverse axial direction, and an oblique lower end face that faces in the axial direction, the oblique end faces each having such an outer geometric shape, extending in a direction not perpendicular to the longitudinal axis, that, as a result of the axial distance between the upper support and the lower support being reduced, respectively adjacent spreading elements are displaced in substantially opposite radial directions by means of the radial play, and the axial force is in each case converted to a radial force in the radial directions, a first movement portion comprising and the first movement portion and the second movement portion being axially displaceable in relation to one another for the purpose of varying the axial distance between the upper support and the lower support, and the second movement portion axially coupleable to the drilled hole in the axial direction, and wherein the shank is composed of an upper shank portion and a lower shank portion pushable into one another, in particular in a telescopic manner, along the longitudinal axis, the upper shank portion, with the upper shank end and the upper support, constitutes the first movement portion, and the lower shank portion, with the lower shank end and the lower support, constitutes the second movement portion.