US 5,643,069 AGranted

Drill for drilling brittle materials

AssigneeHeraeus Quarzglas GmbH & Co. KG

InventorsUwe Christiansen, Dagobert Knieling, Andreas Schultheis

Life of this patent

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Abstract

A drill head carries a plurality of coaxially mounted drill crowns beginning with a first crown and followed by additional drill crowns which, upon rotation, describe concentric envelope circles of successively larger diameters. The first drill crown has cutting elements with a diamond coating with an average particle size of 200-1,000 .mu.m, and the additional drill crowns have cutting elements with a diamond coating with an average particle size of 200-300 .mu.m. The difference in diameter of succeeding drill crowns is successively small. Alignment of the drill crowns in a pilot hole is achieved by guide elements mounted behind the drill crowns and describing an inner envelope circle which is smaller than the outer envelope circle described by the largest drill crown, thereby defining a radial safety gap into which fluid is fed to form a cushion during rotation.

Claims16

Dependent claims

Drill for brittle materials, said drill comprising a drill rod having a forward end and a longitudinal axis of rotation,

a drill head mounted at said forward end of said drill rod,
a first drill crown mounted on said drill head distally with respect to said drill rod, said first drill crown having first cutting means which, when said drill is rotated, describes a first envelope circle, said first cutting means having a diamond coating with an average particle size in the range of 200-1,000 .mu.m,
at least one additional drill crown including a second drill crown mounted behind said first drill crown, said second drill crown having second cutting means which, when said drill is rotated, describes a second envelope circle coaxial to and larger than said first envelope circle, said second cutting means having a diamond coating with an average particle size in the range of 200-300 .mu.m wherein said drill crowns are replaceable disks, said cutting means comprising a plurality of segments mounted on the circumference of each disk, said diamond coatings being provided on said segments.

Dependencies are inferred from the claim text.

Facts

Application: 08/531,413Filed 21 Sep 1995
Priority: DE 44 34 025.723 Sep 1994
Granted: 1 Jul 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

B28D 1/14
Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor: by boring or…
B24B 5/48
Single-purpose machines or devices: for grinding walls of very fine holes, e.g. in drawing-dies
B28D 1/18
Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor: by milling,…
B28D
Working stone or stone-like materials