United States Patent 2132493

This invention relates to bits and has for an object the provision of a bit of the character wherein the blades or cutter elements thereof may be replaced with new devices of the same character. The invention has to do with that type of bit utilizing a stationary type of cutter element., The...

Phipps, John T.
Application Number:
Publication Date:
Filing Date:
Herman, Smith C.
Primary Class:
Other Classes:
175/232, 175/393, 175/413, 175/421
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This invention relates to bits and has for an object the provision of a bit of the character wherein the blades or cutter elements thereof may be replaced with new devices of the same character. The invention has to do with that type of bit utilizing a stationary type of cutter element., The inventor is aware that attempts have been made by prior investigators to provide a bit of the character stated, but so far as the inventor is aware, most of said attempts have been failures under actual service conditions. The present device, however, has been tried out under the most severe working conditions and found satisfactory. An object of the invention is to provide a bit having its parts so arranged and constructed as to permit circulation adjacent the formation to be cutter-chipped by the blade elements of the bit. . : Another object is the provision of a bit which may be easily cleaned.

Another object is the provision of a bit wherein the body member, which is usually the most expensive portion of a bit, may be used repeatedly with new blades associated therewith.

It is customary when drilling a well hole through formation which is difficult to drill, to use a new blade or blades after each drilling operation. The blades become chipped, broken and dull, with the result that the drilling is unsatisfactory. If the entire bit must be discarded, considerable expense is incurred in the operations.

Consequently, my invention is a money saver.

Other objects include a bit incorporating many novel features of construction, as well as features wherein the blade elements are held to the body.

With the above mentioned objects and others in view, including inexpensiveness in cost of manufacture, durability in use, and general simplicity of structure, the invention consists in the novel and useful provision, formation, construction, association, and relative arrangement of parts, members and features, all as shown in a certain embodiment in the accompanying drawing, described generally, and more particularly pointed out in the claims.

In the drawing: Figure 1 is a side elevation of the improved bit, 50 Figure 2 is a bottom plan view of the bit, showing the blade elements, Figure 3 is a cross sectional view on the line 3-3 of Figure 1, Figure 4 is a side elevation of the blade structure, Figure 5 is a sectional view on the line 5-5 of Figure 2, and, Figure 6 is a fragmentary sectional view on the line 6-6 of Figure 2.

Referring now with particularity to the drawing, the improved bit is designated as an entirety by the numeral I and the same includes a body 2 adapted to have inserted therein, in a manner to be hereinafter set forth, a blade or blades 3. As this tool is adapted to be used with rotary apparatus, the body is provided with a longitudinal bore 4. One end of the body may be provided with a pin 5, an enlarged portion 6, a reduced portion 1, finally merging into what may be termed the bottom or base portion 8 of the body. 14: This portion 8, in the present embodiment of the invention, is provided with one or more slots and, in the present instance, two diagonal slots are shown at 9 and 10. These slots cross. Adapted to be received within the slots is a wing type blade structure, heretofore designed as 3 but for purpose of more convenient designation, will hereinafter be designated as 3a and 3b. It will be noted that each blade structure 3a and 3b is of extended length and cast integral, with end portions of the blades extending beyond the base of the body 8. The leading edge of each half blade is provided with a water course in the form of a facial groove or slot, as shown at i , 12, 13, and 14. The slots or grooves II and 13 of the blade structure 3b merge so as to be in communication with the central bore 4 of the body (see Figure 1) and the same is true for the slots or grooves 12 and 14, for the blade structure 3a. This wing type blade structure utilizes wings of different characters; for instance, while both wings are substantially of the fish tail type, still the blade 3b has a greater depth than 3a although the cutting edge of both blades is substantially in the same cutting plane. The blade structure 3b, which is of lesser depth than that of 3a, is also cut away from the cutting edge portion for both ends of the blade to where it merges with the blade 3a, as best shown in Figure 4 at 15. The rear faces of all the blades may be provided, and are so provided in the present instance, with strengthening ribs 16.

The head or base 8 of the body at the zone marked 11 is provided with lugs -18 adjacent the grooves 11, 12, 13, and 14 (see Figure 6). To assemble the device, the blades are both notched inwardly, as indicated at 19 and 20 and tapped bores are provided in the head or base 8 at 21 and 22, whereby partially threaded pins 23 may be screw-threaded within the said threaded I5 bores and be received within the notched portions 19 and 20 when the blades 3a and 3b, respectively, are in position within the blade receiving slots of the head or base. - Thus, through the simple expedient of providing two threaded pins, it is possible with this present invention to securely lock the blades in position within the head or base of the body.

The operation, uses and advantages of the invention just described are as follows: After the blades have been assembled within the base or head 8 of the bit, it will be observed that the blades are so shouldered within the slots of the body as to readily communicated any torsional strain directly to the body. The only function performed by the pins 23 will be to hold the blades within the slots of the base. We assume that the bit has the pin member thereof joined with the drill string, and that the device is within a well hole and in the act of boring said hole. Mud laden fluid is, of course, forced through the drill string, the bore 4, and outwardly through the slots II to 14, inclusive, on the leading face of each blade. As the drilling operation proceeds, the cuttings, are prevented from closely concentrating adjacent what might be termed the central zone or the crossing portion of the wing type bit by the construction shown, wherein the blades 3a are curved upwardly at the zone marked 15 in Figure 4. Thus, actual cutting at this particular zone and for a portion outwardly from the apex of the cutting edge of the blades 3b, is totally accomplished by the said blades 3b and in this manner, the cuttings do not interfere with the blades 3a. The cuttings may, therefore, be readily washed away, the blades constantly acting upon new formation.

Stress is readily resisted through the provision of the webs or enlargements 16 on the rear surfaces of the blades.

It is well known that blades tend to wear very rapidly in actual service, and that if the blades should break or wear off unduly, due to any long or continued service, that the base of the body of 4Y the bit might become damaged so that further use thereof would be impossible. To overcome any difficulty of this character, the lugs 18 are provided adjacent the facial grooves which act as a water way for each blade, and said lugs depend below the surface of the base 8. Thus, if the blades wear down, the lugs will strike the formation being cut and the lugs, by being positioned on the leading surface of each blade, will be deformed and forced into the facial grooves just mentioned, thus closing off circulation through the bit. This stoppage of circulation will be immediately discovered by the well operator at the surface of the well and he will thereby be apprised of the fact that something has gone wrong. In this case, it would be that a blade had been broken or worn to a point where damage to the body would result upon further use of the bit. If the contingency just men- ] tioned is the cause of stoppage of flow through the bit, then the drill stem with its attached bit, may be withdrawn to the surface of the well and a new set of blades inserted within the body, the old blades dropping from the body through the ou mere expediency of removing the pins 23.

I claim: 1. A bit including a body and wing type blades secured to said body, said body formed with a central water course, and said blades provided a on the leading faces thereof with facial slots communicating with the water course of said body, and a deformable means adjacent each facial slot of said blades; said deformable means adapted to close the slots in the blades when the 3 blades become worn a predetermined degree.

2. A rotary type bit adapted to be secured to a drill string, through which string and bit liquid is passed under pressure, said bit including a body provided at one end with a head, a blade adapted for partial reception within said head, the leading face of said blade provided with a slot and said body provided with a central bore in communication with said slot and the drill string, and deformable means adjacent the slot of said blade; said deformable means adapted close the slot in the blade when the blade becomes worn a determined degree, to thereby prevent injury to the body by stopping liquid flow through said bit and thereby indicating to the operator of the bit 4 a stoppage of liquid flow through the drill string.