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US 4,729,441 AGranted
Rock drill
AssigneeHawera Probst GmbH & Co.
InventorsWolfgang Peetz, Bernhard Moser
Life of this patent
Estimating the term…
Abstract
A rock drill in which the depth of the recessed groove for accommodating the cutting body is made greater than the axial brazing-in depth of the cutting body whereby a largely stress-free seating of the cutting body results. In particular, for rock drills for making break-throughs, this recessed groove extended in the radial direction into lobes of a drill head can be used for locating cutting bodies in the lobes.
Claims12
A rock drill comprising:
- a drill head body having a longitudinal axis and having at least one radially projecting recessed groove provided therein, which recessed groove has a pair of sidewalls and a bottom surface, which bottom surface extends from one sidewall to the other sidewall, and which recessed groove extends the entire width of the drill head body, and has a groove depth measured along said longitudinal axis;
- and
- at least one cutting body seated in and brazed together with said at least one radially projecting recessed groove, which cutting body has a lower edge, which lower edge faces the bottom surface of the recessed groove, and a groove penetration depth measured along said longitudinal axis,
- wherein said groove depth is greater than said groove penetration depth, whereby a clearance space is defined between the bottom surface of the recessed groove and the lower edge of the cutting body prior to and after brazing, such that a stress-reduced seating of said at least one cutting body is provided after brazing.
1 more element
A rock drill for making break-throughs, comprising:
- a drill shank having a longitudinal axis;
- a drill head body positioned at one end of said drill shank and having at least one pair of radially projecting, diametrically opposing lobes and having a center extension positioned centrally and extending outwardly therefrom along said longitudinal axis, said drill head body having at least one radially projecting recessed groove provided therein, each said at least one radially projecting recessed groove having a pair of sidewalls and a bottom surface, which bottom surface extends from one sidewall to the other sidewall of said at least one radially projecting recessed groove, each said at least one radially projecting recessed groove extending radially through one of said at least one pair of radially projecting, diametrically opposing lobes and said center extension, and having a groove depth measured along said longitudinal axis;
- at least one cutting body seated in said center extension and brazed to that portion of the at least one radially projecting recessed groove which extends through said center extension, each said at least one cutting body having a lower edge, which lower edge faces the bottom surface of the recessed groove, and a groove penetration depth measured along said longitudinal axis;
- and
- a plurality of cutting bodies seated in and brazed to that portion of said at least one radially projecting recessed grooves which extends through at least one of said at least one pair of radially projecting, diametrically opposing lobes,
- wherein said groove depth is greater than said groove penetration depth of said at least one cutting body seated in said center extension, whereby a clearance space is defined between the bottom surface of that portion of the at least one radially projecting recessed groove which extends through said center extension and the lower edge of said at least one cutting body prior to and after brazing, such that a stress-reduced seating of said at least one cutting body is provided after brazing.
3 more elements
Dependencies are inferred from the claim text.