DE1235237B - Extension roller chisel - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

E21b

German class: 5a-

Number: 1235 237

File number: B 61648 VI a / 5 a

Filing date: March 13, 1961

Open date: March 2, 1967

The invention relates to an extension roller bit with a freely rotatably mounted roller sleeve, a ring tooth is provided on its outer end.

A roller chisel is already known (French Patent specification 1 252 535), on whose roller sleeve a number of ring teeth are arranged. at This roller chisel prevents the further ring teeth sitting behind the outer ring tooth from unhindered Discharge of the material to the pre-ear hole and also crushed through the outer ring tooth blasted off material in an undesirable manner.

With a likewise known embodiment of a roller bit (US Pat. No. 2,851,253) these disadvantages cannot be eliminated. Apart from the fact that this roller bit is not an extension roller bit, but on a closed one The bottom of the borehole is working, the radially extending ones are connected to the ring-tooth-like outer edge Teeth so high that they can already be seen when pre-notching through the ring-tooth-like collar Crush rock before the notch depth is sufficient to blast off larger pieces of rock. The invention provides an expansion roller bit with a freely rotatably mounted roller sleeve, on the outer end of which a ring tooth is provided, proposed which is characterized in that the cross section of the roller sleeve on its surface adjoining the working area of the ring tooth transversely to the axis of rotation of the roller sleeve is out of round and with respect to the axis of rotation radially on most protruding parts of this surface protrude significantly less than the ring tooth.

The roller sleeve can be designed as a polygonal prism.

In the formation of an expansion roller bit according to the invention the outer ring tooth is capable of being deep and in many cases bursting off to cut a sufficient notch in the borehole shoulder of rocks without the The free surface of the rock behind the ring tooth is also crushed.

Due to the prior art, the person skilled in the art is already aware of the notches provided there of the rock through the ring tooth effective elevations on the surface behind the ring tooth distracted by this thought.

The drawing shows an embodiment of the expansion roller bit according to the invention, and although in

F i g. 1 is a partially sectioned side view and in FIG

Extension roller bits

Applicant:

J. C. Söding & Halbach, Hagen (Westphalia)

Named as inventor:
Karl-Günther Bechern,
Berchum via Hagen (Westf.)

F i g. 2 and 3 each section along the line AB through different embodiments of a roller bit according to the invention.

It can be seen from Fig. 1 that on the possibly via a socket on the pin 1 via ball and roller sleeve 4 placed on roller bearings 2, 3, a ring tooth 5 is screwed on at the front end. This Ring tooth 5 works on the bottom of the borehole 6 and undercuts it at point 7. Normally the part of the borehole bottom running inward from point 7 breaks after reaching a certain point Penetration depth towards the pilot hole. With a corresponding width of the borehole bottom 6 or less favorable Due to the nature of the mountain range, however, there is sometimes the possibility that the ring tooth 5 at 7 is completely incorporated into the bottom of the borehole, so that the roller sleeve 4 with its outer surface on the bottom of the borehole comes to rest. In this case, the drilling rig then revolves empty. Here is according to the invention This remedy is created in that the roller sleeve adjoins the one behind the ring tooth 5 Surface 8 is non-circular, with the parts that protrude most radially with respect to the axis of rotation this surface project much less than the ring tooth 5.

Fig. 2 shows the design of this area as Hexagon, while F i g. 3 indicates the attachment of lugs 9 on the conical surface. These Approaches can be interchangeable and are also expediently made of a more wear-resistant material than the roller sleeve 4 made.

Claims (1)

Patent claims: 1. Extension roller chisel with a freely rotatably mounted roller sleeve on its outer End of a ring tooth is provided, characterized in that the cross section of the 709 517/51