Boring or penetrating the earth – Bit or bit element – Impact or percussion type
Patent
1995-12-13
1998-05-05
Dang, Hoang C.
Boring or penetrating the earth
Bit or bit element
Impact or percussion type
761082, 175374, E21B 1054
Patent
active
057462810
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method for mounting hard metal buttons in a drill bit, in which the substantially cylindrical hard metal buttons are mounted by means of compression connection in holes formed in a drill bit body portion to be tempered at a high temperature, the holes having a substantially round cross-section and being formed before the tempering of the body portion.
The invention relates further to a drill bit, comprising a drill bit body portion to be tempered at a high temperature, holes formed in the body portion and having a substantially round cross-section and substantially cylindrical hard metal buttons to be mounted in the holes by means of compression connection, the holes for the hard metal buttons being formed in the body portion before the tempering of the body portion.
A traditional problem with rock drill bits has been durability. At drilling, a rock drill bit becomes dull rather quickly, which decreases the drilling capacity. Attempts have been made to solve the problem by attaching various point portions manufactured of a very hard material to the point of a drill rod. For attaching a point portion directly to a drill rod, the hard metal portion has to be connected to the drill rod by brazing or some other similar method. To drill rods is generally connected a so-called drill bit, which can be attached by means of a threading or in some other corresponding manner. The hard metal portions required by the drill bit may then be jointed separately to the bit, due to which it is not necessary to change the whole drill rod when the drill bit wears or breaks, but it is enough to replace the drill bit only.
British Patent Applications 2 136 035 and 2 099 044 as well as U.S. Pat. Nos. 4,570,725 and 4,350,215 disclose various drill bits intended for rotary bits, to which are jointed hard metal buttons by brazing to facilitate drilling. However, since these drill bits are not used for percussion drilling, hard metal buttons can be mounted in them in a considerably easier manner than in drill bits intended for percussion drilling. Rotary bits drill into a material to be worked by scraping the bottom material of a hole in the first place, due to which the material to be drilled is not subjected to a percussive force of any kind. Accordingly, the drill bits and the mountings of hard metal buttons thereto disclosed by said publications differ entirely from the drill bits intended for percussion drilling.
Finnish Patent Application 964/64 discloses a drill bit intended for percussion drilling, in which a hard metal point portion is jointed by brazing to an opening formed in the point of a drill rod and having substantially the form of the hard metal point, whereby the hard metal point aligns with the mid-line of the drill rod. The use of this solution proved to be economically more expensive when hard metal button bits were introduced to the market. Further, it shall be taken into account that it is not possible to change a separate drill bit to this drill rod, but the whole drill rod has to be replaced when the hard metal portion wears.
Finnish Patent Application 780 154 describes a rock working tool and an insert mounted therein by brazing. The insert is mounted only by brazing in said rock working tool and the invention of the publication relates only to a centering of the insert in the point of the rock working tool. The problems of the rock working tool are thus the same ones as set forth in connection with the previous application.
Finnish publication 893 574 describes a drill bit provided with hard metal bit portions, in which separate support plates guide a hard metal point into a groove made in the point of the drill bit, which plates are then, together with the hard metal bit, brazed into the point of the drill bit to achieve a uniform assembly. Furthermore, it is a very cumbersome and time-consuming working process to mount a hard metal bit in a drill bit by means of various support plates. Also this solution is economically inferior to the button bit used at present.
U.S. Pat. No. 2
REFERENCES:
patent: 2707619 (1955-05-01), Andersson
patent: 2750156 (1956-06-01), Coates
patent: 3294186 (1966-12-01), Buell
patent: 3600795 (1971-08-01), Brundlin et al.
patent: 4350215 (1982-09-01), Radtke
patent: 4453775 (1984-06-01), Clemmow
patent: 4570725 (1986-02-01), Matthias et al.
patent: 4676124 (1987-06-01), Fischer
patent: 4744270 (1988-05-01), Vezirian
patent: 4867015 (1989-09-01), Kane et al.
patent: 4873895 (1989-10-01), Taylor et al.
patent: 4951762 (1990-08-01), Lundell
patent: 5172780 (1992-12-01), Batliner et al.
Dang Hoang C.
Oy Robit Rocktools Ltd.
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