US1522593A - Rotary drilling tool - Google Patents

Description

Jan 3, i925. 1,522,593

R. o. PICKIN ROTARY DRILLING TOOL Original Filed 061;. 1 1919 Patented .an. 13, 1925.

UNITED STATES PATENT OFFICE.

ROTARY DRILLING TOOL.

Application filed October 13, 1919, Serial No. 330,259. Renewed April 12, 1924.

To all 107mm, iii-may concern:

Be it known that. I, ROWLAND O. PICKIN, a subject of the King of Great Britain, residing in Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Improvement in Rotary Drilling Tools, of which the following is a specification.

This invention relates in general to improvements in rotary drilling tools and has more particular reference to rotary drill bits adapted for use in drilling holes in rock strata of varying hardness.

The principal object of the invention is the provision of a rotary drill bit of new and improved construction and adapted to operate efficiently and economically in the cutting of earth and rock strata, having wide range of hardness, i. e. adapted to cut effectively in strata varying from very soft to very hard.

A further and highly important object of the invention is the provision of a bit operable at great efliciency with a scraping QC tion, and yet so constructed that the parts wearing may be readily replaced.

A further and important object of the invention is the provision of a rotary drill bit which acts by a scraping action on the side of the hole, and which will be so constructed and arranged that it will require a relatively small amount of abrasive or cutting material.

Another object of the invention is the provision of a bit of this character which may be cheaply manufactured, readily installed and easily operated with any of the usual appropriate drilling apparatus.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which taken in connection with the accompanying drawing discloses a preferred cmhodiment thereof.

Referring to the drawing:

Figure 1 is a side elevation of a drill bit embodying my present invention.

Figure 2 is a similar view taken at right angles to the view in Figure 1.

Figure 3 is a section taken substantially on the line 33 of Figure 1.

Figure 4 is a plan view of one of the cutting studs.

Figure 5 is a transverse section through the same.

Figure 6 is a plan view of one of the abrasive cutting elements, and

Figure 7 is a longitudinal section through the same.

For the purpose of illustrating my invention I have shown on the drawing a drill bit in which it is embodied and adapted for attachment to a drill rod of any useful or preferred construction. The bit comprises a body or head 11 preferably of one piece and flattened at its sides, as indicated at 12. The remaining faces are preferably formed of transversely curved sides 13 which extend down and around into a similarly formed bottom face 14. In the embodiment of the invention shown on the drawing the side and bottom faces 13 and 14; are the faces carrying the cutting elements, and these faces extend throughout the zone of cutting operation. In the embodiment of the invention shown on the drawing two series of outwardly projecting studs 15 are provided. The studs of each series extending lengthwise of the faces and the studs of the two series being staggered with relation to each other and over-lapping, so that when the, drill is rotated continuous cutting at all points is accomplished. The cutting is done by grinding action and the studs carry abrasive elements which cut into the bottom of the hole, and in so far as may be necessary into the sides of the hole, the side action being of course largely a smoothing and finishing one.

As has been stated the faces'13 and 14 are curved transversely and the cutting elements are or may be arranged on opposite sides of a vertical transverse center.

In the present instance each cutting element comprises a carrier member 16 having an operative end of a honeycomb construc tion, 1'. e. that is to say it is perforated so that much of the material is removed. Larger perforations 17 are provided in which abrasive sticks 18 are inserted and each of these sticks is preferably of cylin drical form and is surrounded by a cushioning sleeve 19 of copper or other soft and relatively yielding material. The abrasive material of the sticks 18 may be carborundum, extremely hard steel or the like and these cutting elements are made hollow, as indicated at 20, to provide additional cutting surface edge and to reduce the amount of material necessary. Additional holes 21 are provided in the carrier to reduce the amount of material in the operative end of the stud so that as the abrasive elements wear down the relatively softer material of the carrier may more easily be Worn away. The shank of the carrier is provided with an opening 16 in the present instance .for securing it in place and the material is further slit, as indicated at 22; Openings or apertures -23 extend into the head at the proper locations and receive the shanks 16 of the studs. The openings 16 are brought in registration with openings 24 in the sides of the head so that bolts 25 in threaded engagement with the stud shanks may be inserted; inner recesses 26 being provided to take the ends 27 of the bolts.

It will be manifest that various changes may be made in the form of the head, in the cutting elements themselves and in their arrangement on the head and that a less number of them may be'used, and also that they may even be combined with other cutting devices, all Without departing from the spirit and scope of the invention, the form of the invention hereinbefore described being merely a preferred embodiment thereof and employed solely for the purposes of illustration, it being understood that all structures that come Within the terms of the ap pended claims are considered to also embody the invention.

I claim:

1. A rotary drill bit comprising a perforated head, carriers for carrying groups of cutting elements and inserted in the head and individually secured in place, and groups of cutting elements secured in said carriers.

2. In a rotary drilling tool, a body, a plurality of rigid cutting studs inserted into said body, each having portions of its cutting face perforated for the purpose of forming a plurality of cutting edges.

ROWLAND O. PICKIN.

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