US1427019A - Curved-wing rotary bit - Google Patents

Description

'9. E. PUIAIAIIII.

CURVED WING ROTARY BIT.

APPLICATION FILED Nv.27, 1920.

LMP/@19, PAIQDIQAAIIg. 2.2, A922."

JM ATTYS vnarran stares storten n; remnant, or Los ANGELES, CALIFORNIA.

enlever-wine ROTARY Brr.

mancia,

Specification of Letters Patent.

Patented Aug. 22, i922@ Application :filed November 27, 1920. Serial No. 426,856.

vide a rotary drill bit so arranged that the cuttingsl made by the drill bit will be forced vtoward the axis of the bit where they may be readily washed away by a stream df water discharged through the shank of a bit in usual manner. This arrangement whereby the cuttings are forced away from the side edges of the bit andtoward its axiswill also prevent said cuttings obstructing the rotation of the -bit by said cuttings between the bore cut by the bit and the side edges of the latter.

`llt is a further object of the invention to provide a bit of this character having cutting edges arranged upon its side edges for trimming the bore cut bythe bit.

llt is a still further object of the invention to provide a bit which is so constructed as to increase the length of the end cutting edge of the bit without increasing the transverse width of' said bit.

rlhe invention will be readily understood from the following description of the accompanying drawings, in which- Figure l is a side elevation of the bit constructed in accordance with the invention.

F ig. 2 is a transverse section on the line e-e of rig. i.

Fig. 3 is a detail section on the line 3-3 of Fig. l.

rlhe bit consists of a blade 1 having the usual shank?, projecting axially beyond its upper edge and provided with the usual threaded pin 3 for coupling the bit to a drill rod. lWater is supplied to the opposite surfaces of the drill bit in the usual manner through conduits l extending through the shank and discharging against the respective surfaces of the bit at its upper edge.

rEhe drill bit instead of comprising a plane packing cutting surface in transverse section is formed substantially S-shaped in transverse section as clearly shown in Fig, 2, the respective loops of the S extending laterally from opposite sides of the axis of the bit. By this arrangement pockets 5 are provided in the respective surfaces of the drill bit at opposite sides of the axis of the same and said pockets terminate at the side edges of the bit in outwardly curved portions 6. These curved portions 6 are formed as cutting edges which extend the length'of the side edges of the bit.

The end cutting edge of the bit provided at the lower edge of the same preferably consists of the two usual cutting edges 7 curving downwardly from the axis of the bit to the respective side edges of the same. rlhese end cutting edges are also curved outwardly from the respective surfaces of the bitbeneath the pockets 5 as shown at 8 in Fig. 3 in order to form end formations for said pockets. A

lt will be observed that a bit as thus constructed provides appreciably longer cutting f edges 7 for a bit of a certain transverse width than isobtainable with a bit of plane transverseformation. lt will also be observed that when a bit as thus constructed is in use the pockets 5 will cause the cuttings to be moved toward the axis of the bit instead of outwardly toward the side edges of the same, it being understood of course that the pockets 5 are arranged in the advance surfaces of the bit when the latter is rotated. lt will also be noted that the side edges for the bit provide means for trimming the bore cut by the bit, the movement of the cuttings toward the axis of the bit keeping these side cutting edges free from cuttings so that they may properly trim the bore. rlhe movement of the cuttings toward the axis of the bit will also permit more ready rotation of the latter and thereby reduce the power necessary to drive the bit.

`While l have illustrated and described the invention as applied to a two wing bit it will be understood that the invention is also applicable to a bit having a greater number l,of wings, Vthe wings of the bit irrespective 'of the number of ille saine being curved to llforin pockets 5 and outwardly curved side yforming side cuttingedges, and cutting 'ends ledges 6 in the advance surfaces of the wings 'upon said wings curving downwardly and i0 in the direction of rotation. outwardly from the aXis of the bit, and ter- Various changes may be made in the conrnin'ating in cutting edges meeting the Side 5 struction as thus set forth without departing cutting edgesl at substantially right angles. from the spirit of the invention. v In testimony whereof I have signed my What is claimed is: name to this specication.

A rotary loit having radially curved wings l GEORGE E. PUTNAM.

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