US2817496A - Expendable drill bit and adapter - Google Patents

Description

Dec- 24, 1957 E. E. JONES ETAL EXPENDABLE DRILL BIT AND ADAPTER 2 Sheets-Sheet l Filed Aug. 6, 1954 FIG.

W Z @AKA/ w f N Tlf IN VEN TOR. EMUA/ E. JUANES Dec.. 24, 1957 E. E. JONES ErAL 2,817,496

EXPENDABLE DRILL BIT .AND ADAPTER Filed Aug. 6, 1954 2 Sheets-Sheet 2 INVENTOR. ro/wmv@ E- Jones @oas-.era. wfc'me Unite States Patent EXPENDABLE DRILL BIT AND ADAPTER Edmund E. Jones, Houston, Tex., and Robert L. Wieke, Houma, La.

Application August 6, 1954, Serial No. 448,286

2 Claims. (Cl. Z55-61) The present invention relates generally to earth-working tools and specifically to a drill bit and adapter therefor for use in making seismic surveys, and in which the drill bit is of such construction that it is easily dislodged after drilling from the end of the drill casing.

In the eld of oil exploration, many holes are drilled or sunk in the plotted geological strata for the purpose of setting olf minor explosions of calculated intensities and the waves of energy are recorded as they are produced and reflected from underground formations.

It is of primary importance to this field work that holes are not of the great depth required for true oil well exploration, but are in relatively large numbers and are in what is termed in the industry as soft ground, as contrasted to deep or hard rock drilling.

The principal object of the present invention is to provide such an inexpensively constructed drill bit that its recovery from the drill hole is impractical and its expendability a factor in saving a portion of the cost of drilling.

Another object of the invention is to provide a drill bit which is frictionally held in drilling position on the drilling casing by means of a specially constructed adapter.

A further object of the present invention is to provide a drill bit and adapter to use on drill casings without alteration of the drill casing in any manner, and which may be installed or removed with ordinary tools.

These and other objects and advantages of the present invention will be fully apparent from the following description when considered in connection with the annexed drawing, and in which:

Figure l is a view in elevation o' the present invention in a hole drilled by it,

Figure 2 is a bottom view of the invention,

Figure 3 is a cross sectional side view taken on the line 3-3 of Figure 1,

Figure 4 is a cross sectional end view taken on line 4 4 of Figure 1,

Figure 5 is a view in cross section showing the action of a push-rod in dislodging the drill bit from the adapter and drill casing, and

Figure 6 is an exploded view in perspective of the present invention.

Referring in more detail to the drawing in which like l numerals indicate like parts throughout the several views,

the invention is seen to consist of a drill bit or head having an upper end portion 1li which is of U-shape configuration and an adapter indicated generally at 11, the latter being formed with internal threads 12 at its upper end 13 for mounting the adapter 11 on the lower end of a drill casing 14, having matching threads 15.

It will be seen that the drill casing 14 is undercut at 16 and that the adapter 11 is formed of a collar or sleeve 17 having no greater diameter than the casing 14 except 2,817,496 Patented Dec. 24,` 1.95.7

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at the ilanges- 184 and 19, which are. in pairs on opposite` sides of the sleeve 17 exteriorly thereof and extending longitudinally from one end to the other of the sleeve and forming keyways thereon. The legs 21 of the head. or drill bit U-shaped upper end portion 10 have sloping upper ends 23. The lower end of the drill bit is provided with cutting blades 24 and 25 of the type known in the industry as fish-tail blades, dependingly carried by the bight of the drill bit and extending the full width of the bight with cutting edges 26 and 27, respectively. A plate 2S is positioned within the lower end of the sleeve 17 and extends transversely to the bight and is integrally secured to the bight on the upper side of the latter, and is seen in Figures 2 and 5 to be substantially rectangular in shape and fitting within the end of the sleeve 17.

In Figures 1 and 5, the assembled drill bit and adapter is seen in a hole in the ground 31, and in Figure 5 a push-rod 32 has been lowered into the drill casing 14 and with the drill bit and sleeve 17 raised a few inches, the push-rod 32 bears against the plate 28 and can push the drill bit 10 ott the end of the sleeve 17 to the position 10a, shown in dotted lines in Figure 5, permitting the easy withdrawal of the sleeve and drill casing. The drill bit 10 is left in the hole as expendable and a suitable explosive is lowered into the hole and set ott.

It will be seen that the withdrawal of the sleeve and casing is relatively easy and unimpeded, for the reason of the greater width of the cutting teeth and therefore the resultant hole, and the sleeve 17 is preferably formed with inwardly sloping end edges 33 and an inwardly disposed sloping shoulder 34 permitting relatively greater strength, and having the longer of the two flanges on that side of the leg 21 to bear against the leg in the direction of the cutting action of the teeth.

While a single embodiment of the present invention has been here shown and described, other embodiments are contemplated and other changes and modications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. An expendable drill bit and adapter comprising a sleeve adapted to be threadedly secured to the lower end of a drill casing for rotation therewith, diametrically opposed pairs of parallel spaced ilanges extending exteriorly and longitudinally on said sleeve from one end to the other end thereof and forming keyways, a head having an upstanding U-shaped upper end portion arranged so that its bight extends across the lower end of said sleeve with each of its legs frictionally engaged in the adjacent keyway and constituting the sole means of attachment to said sleeve, cutting blades below said bight and dependingly carried by the latter, and a plate positioned and fitted within the lower end of said sleeve and extending transversely of the bight and xedly carried by said bight adapted to be struck by the lower end of a push rod inserted in said drill casing for detaching said. head from said sleeve.

2. An expendable drill bit and adaptercomprising a sleeve adapted to be threadedly secured to the lower end of a drill casing for rotation therewith, diametrically op posed pairs of parallel spaced iianges extending exteriorly and longitudinally o-n said sleeve from one end to the other end thereof and forming keyways, an upstanding U-shaped head arranged so that its bight extends across the lower end of said sleeve with each of its legs frictionally engaged in the adjacent keyway and constituting the sole means of attachment to said sleeve, cutting blades below the bight and dependingly carried by the latter, and

a plate positioned and fitted within the lower end of said sleeve and extending transversely of the bight and xedly carried by said bight adapted to be struck by the lower end of a push rod inserted in said drill casing for detaching said head from said sleeve, one ilange of each pair of flanges extending outwardly from said sleeve a greater distance than the other flange of said pair, the longer flange being disposed relative to the adjacent leg of said References Cited in the le of this patent UNITED STATES PATENTS Layne et al. May 12, 1936 Colquitt June 29, 1954

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