Chisel holder

Patent metadata

Field	Value
Publication number	US-9228434-B2
Application number	US-201113822720-A
Country	US
Kind code	B2
Filing date	Dec 2, 2011
Priority date	Dec 3, 2010
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

The subject matter of the invention is a bit holder for an earth working machine, in particular a road milling machine, having a support member onto which an insertion projection is indirectly or directly attached on an insertion projection side, the insertion projection comprising at least one convex abutment surface and one pressure surface. In a bit holder of this kind, working forces can be dissipated in stress-optimized fashion into an attached base part when provision is made that the insertion projection comprises two convex abutment surfaces that are arranged at a distance from one another.

First claim

The invention claimed is:

1. A tool apparatus for an earth working machine, comprising:
a support member having an insertion projection side and a working side, the working side facing away from the insertion projection side, the working side defining a bit longitudinal center axis; and
an insertion projection attached to the support member and extending from the insertion projection side, the insertion projection having a longitudinal insertion axis, the bit longitudinal center axis of the working side being inclined forwardly relative to the longitudinal insertion axis of the insertion projection to define a forward tool advance direction, the insertion projection including:
at least two convex abutment surfaces circumferentially separated from one another and arranged in front of the longitudinal insertion axis with reference to the tool advance direction; and
at least one pressure surface arranged behind the longitudinal insertion axis with reference to the tool advance direction;
wherein the at least two convex abutment surfaces are circumferentially separated from one another b a recess defined in the insertion projection.

2. The apparatus of claim 1 , wherein:
the at least two convex abutment surfaces each have the same radius of curvature.

3. The apparatus of claim 2 , wherein:
the radius of curvature of the abutment surfaces is in a range of from 16 mm to 32 mm.

4. The apparatus of claim 2 , wherein:
the radius of curvature is constant over a length of the abutment surfaces.

5. A tool apparatus for an earth working machine, comprising:
a support member having an insertion projection side and a working side, the working side facing away from the insertion projection side, the working side defining a bit longitudinal center axis; and
an insertion projection attached to the support member and extending from the insertion projection side, the insertion projection having a longitudinal insertion axis, the bit longitudinal center axis of the working side being inclined forwardly relative to the longitudinal insertion axis of the insertion projection to define a forward tool advance direction, the insertion projection including:
at least two convex abutment surfaces circumferentially separated from one another and arranged in front of the longitudinal insertion axis with reference to the tool advance direction; and
at least one pressure surface arranged behind the longitudinal insertion axis with reference to the tool advance direction;
wherein the at least two convex abutment surfaces each have the same radius of curvature; and
wherein the abutment surfaces are arranged on an identical reference circle.

6. The apparatus of claim 1 , wherein:
the at least two convex abutment surfaces each have the same curvature geometry.

7. A tool apparatus for an earth working machine, comprising:
a support member having an insertion projection side and a working side, the working side facing away from the insertion projection side, the working side defining a bit longitudinal center axis; and
an insertion projection attached to the support member and extending from the insertion projection side, the insertion projection having a longitudinal insertion axis, the bit longitudinal center axis of the working side being inclined forwardly relative to the longitudinal insertion axis of the insertion projection to define a forward tool advance direction, the insertion projection including:
at least two convex abutment surfaces circumferentially separated from one another and arranged in front of the longitudinal insertion axis with reference to the tool advance direction; and
at least one pressure surface arranged behind the longitudinal insertion axis with reference to the tool advance direction; and
wherein the at least two convex abutment surfaces each have the same curvature center point.

8. A tool apparatus for an earth working machine, comprising:
a support member having an insertion projection side and a working side, the working side facing away from the insertion projection side, the working side defining a bit longitudinal center axis; and
an insertion projection attached to the support member and extending from the insertion projection side, the insertion projection having a longitudinal insertion axis, the bit longitudinal center axis of the working side being inclined forwardly relative to the longitudinal insertion axis of the insertion projection to define a forward tool advance direction, the insertion projection including;
at least two convex abutment surfaces circumferentially separated from one another and arranged in front of the longitudinal insertion axis with reference to the tool advance direction; and
at least one pressure surface arranged behind the longitudinal insertion axis with reference to the tool advance direction; and
wherein the at least two convex abutment surfaces each have a length parallel to the longitudinal insertion axis in a range of from 20 mm to 50 mm.

9. The apparatus of claim 1 , wherein:
the at least two convex abutment surfaces each circumscribe an angle about the longitudinal insertion axis in a range of from 30° to 80°.

10. A tool apparatus for an earth working machine, comprising:
support member having an insertion projection side and a working side, the working side facing away from the insertion projection side, the working side defining a bit longitudinal center axis; and
an insertion projection attached to the support member and extending from the insertion projection side, the insertion projection having a longitudinal insertion axis, the bit longitudinal center axis of the working side being inclined forwardly relative to the longitudinal insertion axis of the insertion projection to define a forward tool advance direction, the insertion projection including;
at least two convex abutment surfaces circumferentially separated from one another and arranged in front of the longitudinal insertion axis with reference to the tool advance direction; and
at least one pressure surface arranged behind the longitudinal insertion axis with reference to the tool advance direction; and
wherein the at least two convex abutment surfaces each transition via a convex transition region into an at least locally concave recess.

11. The apparatus of claim 1 , wherein:
the apparatus has a central plane including the longitudinal insertion axis of the insertion projection and including the bit longitudinal center axis; and
the at least two abutment surfaces are arranged symmetrically with respect to the central plane.

12. The apparatus of claim 1 , wherein:
the apparatus has a central plane including the longitudinal insertion axis of the insertion projection and including the bit longitudinal center axis; and
the at least one pressure surface is arranged symmetrically with respect to the central plane.

13. The apparatus of claim 1 , wherein:
the at least one pressure surface is spaced from the attachment of the insertion projection onto the support member by a distance of at least 20 mm.

14. The apparatus of claim 1 , wherein:
the abutment surfaces are spaced from the attachment of the insertion projection onto the support member by a distance of at least 15 mm.

15. The apparatus of claim 1 , wherein:
a surface centroid of at least one of the abutment surfaces is spaced from a surface centroid of the at least one pressure surface by a distance parallel to the longitudinal insertion axis of the insertion projection of no more than 20 mm.

16. The apparatus of claim 1 , wherein:
the longitudinal insertion axis of the inser

Assignees

• Lehnert Thomas
• Buhr Karsten
• Lenz Martin
• Barimani Cyrus
• Hähn Günter
• Kammerer Karl
• Roth Markus
• Diessner Bernhard
• Wirtgen Gmbh

Inventors

• Lehnert Thomas
• Buhr Karsten
• Lenz Martin
• Barimani Cyrus
• Hähn Günter
• Kammerer Karl
• Roth Markus
• Diessner Bernhard

Classifications

• E01C23/088 Primary

  Rotary tools, e.g. milling drums {(for forming recesses to receive marking materials E01C23/0946)} · CPC title

• E21C35/1933

  the picks having a cylindrical shank · CPC title

• E21C35/193 Primary

  using bolts as main fixing elements · CPC title

• E21C35/197 Primary

  using sleeves, rings or the like, as main fixing elements · CPC title

• E21C35/18 Primary

  Mining picks; Holders therefor (planing knives E21C27/44) · CPC title