US 2234451 A
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Description (OCR text may contain errors)
March 11, 1941. B RAQ 2,234,451
BORING TOOL Filed Nov. 29, 1939 INVENTOR.
75W iia/miom ATTORNEY.
Patented-Mar. 11, 1941 UNITED STATES 2,234,451 BORING TOOL Bernard Ransome, Diablo, Calii'., assignor to Bansome Company, Emeryville, Calif., a corporation of California Application November 29, 1939, Serial No. 306,699-
This invention relates to earth boring machines or apparatus of the type disclosed in United States Patents No. 1,928,048 and No. 1,932,068, and especially to boring tools to be used in con- 5 junction therewith.
The boring machine disclosed in the above mentioned patents is particularly intended for boring or drilling holes of varying diameters under streets, highways, railway tracks, etc., and
10 into embankments and hillsides where it is desired to collect and drain away seepage water from underlying strata of clay or the like. The holes when bored may serve as openings through which pipes are inserted for connection with other pipes; or, where drainage is desired, perforated pipe is driven in to serve as permanent drainage ducts. Holes of this character are usually bored horizontally where pipe is to be laid, and at a slight upward angle where drainage is desired. The holes are often 100 feet or more in length, and considerable trouble is encountered in maintaining the hole straight, because of sagging or bending of the boring rod due to its own weight, at points between the boring bit and the boring machine whereby the rod or hit is driven or rotated. Also, in boring through sand, gravel and like formations, there is a tendency for cavein and filling of the hole at points behind the boring bit, and when this occurs great difiiculty 3 is encountered in removing the boring rod and bit. Again, in certain heavy clay formations, thev clay may ball around and behind the bit and materially retard operations.
The object of the present invention is generally to improve and simplify the construction and operation of apparatus of the character described, and particularly to provide boring tools whereby the dimculties referred to are very materially reduced.
40 The boring machine and the tools employed are shown by way of illustration in the accompanying drawing, in which Fig. 1 is a side elevation, partially in section, showing the boring machine set up and the hole started;
Fig. 2 is a vertical longitudinal section of a hole, showing the boring rod and tools in operative position within the hole;
Fig. 3 is a perspective view of one form of boring bit;
'Fig. 4 is an enlarged cross section of a boring or cutting blade;
Fig. 5 is a side elevation, partially in section, of a bit particularly intended for rock and hard 55 formations;
Fig. 6 is a front view of the bit shown in Fig. 5;
Fig. 7 is a perspective view of a combination guide and supporting coupling; and
Fig. 8 is a horizontal section of the type of bit shown in Figs. 5 and 6. 5
Referring to the drawing in detail, and particularly to Figs. 1 and 2, A indicates in general a boring machine of the type disclosed in United States Patent No. 1,932,068; B, the boring rod;
C, a combination guide and supporting coupling; 10
D, the main boring or reaming cutter; and E, a pilot bit. The boring machine, briefly described, consists of a motor 2, driven by compressed air supplied by a hose 3 which is connected with any suitable source of supply. The motor, through reduction gears, drives or imparts rotary movement to the boring rod and bits, and feeding or advance of the boring rod and bits is manually controlled through means of a lever 4. That is, the motor, together with the driving connections required, is slidable or longitudinally movable on the base generally indicated at 5. A pair of toothed rack bars 6 are disposed one on each side thereof, and pawls, not shown, actuated by the lever 4 engage the teeth of the rack bars so that when the operator pushes on the lever in one direction the motor, together with the boring rod and bits, is gradually advanced along the base and into the hole as boring proceeds. Conversely, by reversing the pawls and the operation of the lever, the boring rods and bits may be retracted.
The boring rod employed is supplied in lengths of approximately 4 ft. 8 in. It is provided with male and female screw connections at opposite ends to permit ready coupling or addition of rods as the hole lengthens, and it might further be stated that the rod is about two inches in diameter and has a small interior passage formed therein to permit water under high pressure to be introduced adjacent the cutting bits and to wash away the cuttings.
Where hillsides or embankments adjoining highways, railway tracks, etc., have a tendency to slide, it is usually due to an underlying stratum of clay and flow of water which causes the overburden to slide. An efiective method of stopping slides of this character is to drill or bore numerous holes into the hillside or bank at points where the water stratum or flow is intersected, so as to permit free escape and drainage thereof. These holes are usually bored on an incline just suflicient to permit free flow of drainage water, and are often from to feet, or more, in length.
or gradually assume a greater and greater up- .ward incline. In" the present instance, an aux- "iliary coupling of the'type shown in Fig. 7 is employed at suitable intervals. The coupling consists of a hub member 8 of the same diameter as the drill rod. It has a water passage formed therein, and male and female screw connections at opposite ends to permit it to be coupled between rod sections. A combination guide and supporting sleeve l0 having a; diameter substantially that of the hole to be bored surrounds the hub 8 and is maintained concentric therewith by two or more spokes such as shown at 9. This sleeve may be 4, 6 or more inches inwidth, and as such forms a support (see reference character C in Fig. 1) which prevents sagging of the boring bar at points between the boring machine proper and the forward bits D and E. That is, couplings of the character shown in Fig. 7 may be interposed between every rod or between every second rod or so, as desired, and when they are employed, sagging is prevented and the direction of the hole, whether horizontal or slightly inclined, may be maintained and assured.
In drilling or boring through certain'formations such as sand, gravel and the like, and in fact in any type of formation, it must be remembered that water under high pressure, for instance 100# gauge or more, is continuously being discharged adjacent the boring bits, as indicated at 20 in Fig. 5, to keep the bit cool, to soften the formation, and particularly to carry away the cuttings. A continuous water flow is thus maintained through the hole, and due thereto, and also due to sand and gravel-like formations, caving of the hole behind the bits D and ill will sometimes take place; and when this oc'curs it is almost impossible to remove the boring rod and bits.
. Also, it may be stated that due to the fact that the drill rod is coupled by screw connections, rotation of the rod and bits must always be in one direction, In this direction the bits will cut and advance. If the direction were reversed by the motor 2, the couplings would unscrew, and removal of the rod would be substantially impossible. Where caving orclogging of the hole behind the forward bits takes place, little if any trouble is encountered in the present instance,
as bits of the character shown in Figs. 3 and 5 are employed. I
In rock or hard formations, the bit shown in Figs. 5, 6 and 8 is used. It consists of a hub member Illa surrounded by a sleeve ll supported by spokes l2. To these spokes are bolted or otherwise secured cutting bits I: of the type P rticularly shown in Fig. 8. These bits cut during forward advance. Behind them are one or more angularly disposed cutting blades it. They are pitched in a direction opposite to feed advance,
and if the hole is caved or filled in behind the hits, the rod and bits may be rotated in the same direction, but the pull on the lever l is reversed, and as the rod and bits are being pulled out, the blades 14 will cut their way. out, as they are set on an angle and pitch to do so. Thus the bit shown in Fig. 5 will not only cut its way inwardly when the rotation is in 'one direction, but it will also cut its way out again with the same direction of rotation, due to the reverse angle or pitch of the blades l 4.
In softer formations, such as sand, gravel, clay and the like, the type of coupling shown in Fig. 3 is employed. This again consists of a hub member II, a surrounding sleeve ll supported by'spokes l1, and cutting blades such as shown at I0 and is. The forward blades cut'during forward movement of the rod and bits, while the blades ll, which are set on a reverse angle to the front blades, cut during removal or extraction of the rod and bits.
Where a hole of considerable length or depth is being drilled, bits such as shown in Fig. 3
may be interposed at spaced intervals along the boring rod as a substitute for the coupling shown.
in Fig. '1. Thus they function not only as a support and guide for the boring rod, to prevent sagging or'bending of it, butthey also aid in extraction of the rods and bits where caving has typeshown in either Fig. 3 or Fig. 5, depending upon the character of the formation. To this extent the type of cutter indicated at D might be deemed a reamer, as it is preceded by the pilot bit E. The final size of the hole is thus cut, and whilethe hole of final diameter is being cut the main cutter D is guided not only by the pilot bit E but also by the sleeves l6 placed on the rod at suitable intervals.
From the above descriptionit should appear obvious that the troubles heretofore encountered in boring holes of this character have been substantially eliminated.
Having thus described and illustrated my invention, what! claim and desire to secure by Letters Patent is:
1. a rotary boring tool of the character described adapted for rotation in one direction only, said tool having a central elongated hub, a pair oi radially xtending substantially diametrically opposed cutting blades secured to the front end of the hub and disposed on an angle to cut when the boring tool is being advanced, a similar pair of cutting blades secured to the rear end of the hub, but with the angle reversed so as to cut when the tool is being retracted. a cylindrical sleeve disposed intermediate the front and rear cutting blades and spaced from both, and spokes on the hub securing said sleeve in a position concentric with the hub. I
2. A rotary boring tool of the character described adapted for rotation in one direction only, said tool having a central elongated hub, a pair of radially extending substantially diametrically opposed spokes secured to the hub adjacent the forward end thereof, a cylindrical sleeve concentric with the hub and secured to therefrom, said blades being disposed on an angle throughmrt their 1 to cut during retraction of the tool.
3. A rotary boring'tool of the character described adapted or rotation in one direction only, said tool having a central elongated hub, a pair of radially extending diametrical- 1y opposed'spokes secured to the hub-adjacent the forward end thereof, a cylindrical sleeve concentric with the hub and secured to the spokes, a detachable cutting blade secured to each spoke, said blades extending radially from the hub and being sumciently long to project beyond the outer periphery of the sleeve, to cut a bore slightly larger than the diameter 0! the sleeve, and said bladm being substantially V-shaped in crosssection throughout their length, with the apex of the V pointing in' the directionot rotation of the boring tool, to out during'advance of the tool, a pair of radially extendingsulmtantially diametrically opposed cut-ting blades secured to the hub behind the sleeve and spaced therefrom, said blades being disposed on an angle throughout their length to cut during retraction of the tool, a central passage formed in the hub of the tool and adapted to be connected with a. source of water under pressure, and a pair of radial discharge passages formed in the hub in communication with the central passage, said discharge passages directing water from a point between the inner ends 01' the detachable cutting blades and towards the face upon which the blades are operating.