DE1016660B - Carbide-tipped drill bit with pre-cutter and extension blades - Google Patents

Description

GERMAN

The invention 'goes from bucket well-known hard metal-tipped Drill bit with pre-cutter and interchangeable extension cutting blades that are separate from one another the end. Drill bits are known in which the precutter with the holder of the drill bit is worked from one piece, with a knife serving as an extension cutter, which runs straight through the holder is pushed. There are also drill bits known in which the holder and the extension cutter consist of one piece: in which Pre-cutter is inserted by thread engagement. With other known carbide-tipped. Drill bits the holder for the extension wing consists of a closed ring part that attaches to the boring bar or the drill cutter is attached

All of these known drill bits have the major disadvantage that when changing a cutting part larger valuable parts of the drill bit have to be replaced and become unusable and that the drill bit must be completely unscrewed, which is particularly the case with Drilling hard rock is often necessary and time consuming.

These disadvantages are in the case of a carbide-tipped drill bit that consists of a pre-cutter and at least two interchangeable extension cutting blades, which are separate from one another, are avoided in that, according to the invention, each cutting blade is attached to a body. which is part of a longitudinally divided, rotationally symmetrical hollow body is, which on the inner circumference of a bolt-like, the drill rod receiving sleeve and the axle part connecting the precutter is formed so as to be non-rotatable, and 'whose end faces on both sides diverge towards the axis of rotation of the drilling rig have, with the pre-cutter that can be screwed onto the axle part and the receiving sleeve corresponding conical contact surfaces are provided.

This creates a drill bit in which the individual cutting edges can be largely dismantled and wear parts and at the same time a robust, simple, quick-to-operate solution and attachment of all parts as well as their secure cohesion is achieved. It is very important that everyone Cutting blade is attached to a body which is part of a longitudinally divided, rotationally symmetrical Forms hollow body, and that the end faces of this body are conical in such a way that they come together with the mating surfaces formed on the pre-cutter and on the boring bar receiving sleeve allow these bodies with their cutting blades attached due to the

Carbide-tipped drill bit

with pre-cutter
and extension cutting blades

Applicant:

Dipl.-Berging. Albrecht Graf he,
Sprockhövel (Westphalia), Wittener Str. 39,

and Dipl.-Berging. Hugo nuts,
Sprockhövel (Westphalia), Wittener Str. 68

Dipl.-Berging. Albrecht Graefer,
Dipl.-Berging. Hugo Nüsse and Alfred Pilgrim,

Sprockhövel (Westphalia),
have been named as inventors

If the drill bit is screwed in, the axial pressure that arises must be pressed in the direction of the drill axis. Through this it becomes possible to replace the cutting blades with extremely little expenditure of time, because in this case do not first unscrew the entire core bit, but only loosen the individual parts Need to become. This also has the further advantage that when changing, the cutting the individual parts do not have to be put down and looked up again, which is particularly important when working underground under bad. Lighting conditions is very important.

Preferably, the Bafastigungskörper for the single blade at z. B. two extension cutting blades in the form of a semi-cylindrical Body formed whose central angle is 180 °.

Other advantageous details
can be seen from the drawing,
Embodiment of the invention
It shows

Fig. 1 shows a drill bit according to the invention in longitudinal section and

Fig. 2 is a section along the line AB.
The drill bit shown consists essentially of the following parts: the drill rod receptacles sleeve 1, the screw-bolt-like axle part 9 with the head 2, ά & α. Extension cutting blades 3 and 4 on the body 8, which is part of a longitudinally divided, rotationally symmetrical hollow body and the pre-cutter 5 with the internal thread 6.

709 699/1

of the invention in which a is shown.

The receiving sleeve 1, which is provided with an internal thread for the drill rod, has an inner circumferential Shoulder and a conical face on its side facing away from the linkage. the two extension cutting blades 3 and 4, which are separated from each other, or the Bodies 8 have on both sides conical end faces diverging towards the axis of rotation which they have on corresponding mating surfaces on the one hand. the receptacle 1 and on the other hand on Pre-cutter 5 are formed, rest. The thread engages in the internal thread 6 of the precutter 5 of the screw bolt-like axle part 9, which with its head 2 when screwing together the Drill bit against, the shoulder in, the receiving sleeve 1 rests. In the axle part 9 is a central hole trained for purging while on its exterior. Perimeter flat spots 7 are arranged to to secure the cutting blades 3 and 4 against rotation,

Claims (3)

Patent claims: 1. Carbide-tipped drill bit with a pre-cutter and separated from each other, at least two interchangeable extension cutting blades, characterized in that each Cutting blade (3, 4) is attached to a body (8) which is part of a longitudinally divided, rotationally symmetrical Hollow body, which on the inner circumference of a screw bolt-like, the Joining the bar holder (1) and the precutter (5) together. Axle part (9) is designed to be rotationally fixed and its end faces on both sides in the direction of Axis of rotation of the drill towards diverging conical surfaces have, wherein on the a, uf the axle part (9) screw-on pre-cutter (5) and on the receiving sleeve (1) corresponding conical contact surfaces are provided. 2. Drill bit according to claim 1, characterized in that the schraubbolzenartigei axle part (9) flats (7) on two opposite longitudinal sides. 3. Drill bit according to claim 1 and 2, characterized in that the receiving sleeve (1) has inside an annular shoulder on which the head (2) of the bolt-like inner axle part rests when screwing together the drill bit. Considered publications:
German Patent No. 800 850;
French Patent No. 1,014,236;
"Glückauf" magazine of February 17, 1951, p. 146, figs. 3 and 5; Journal »Kehle und Erz«, 1932, p. 198, fig. 5. 1 sheet of drawings © 709 699/1 9.57