US2370070A

US2370070A - Bit

Info

Publication number: US2370070A
Application number: US442197A
Authority: US
Inventors: John T Phipps
Original assignee: H C SMITH OIL TOOL CO
Current assignee: H C SMITH OIL TOOL CO
Priority date: 1942-05-08
Filing date: 1942-05-08
Publication date: 1945-02-20
Anticipated expiration: 1962-02-20

Description

Patented Feb. 20, 1945.

John T. Phipps,

to Il. C. Smith BIT Huntington Park, Calif., Oli Tool Co., Compton,

signor Calif., a

corporation of California Application May 8, 1942, Serial No. 442,197

1 Claim.

This invention relates to bits, and particularly to cutter bits of the cross roller type.

.At the present time, the ordinary cross roller cutter combines In addition to the cross rollers. side or gauge cutters. These gauge cutters are usually arranged so that the axes thereof are at right angles to the axis of the cross roller cutters. It has been found that the teeth of the gauge cutters Wear quite rapidly in certain formations. Particularly, the outer edges of the teetnof said gauge cutters tend to become dull and rounded. When this occurs, the gauge cutters do not cut the formation in a satisfactory manner, with the resuit that the cross roller cutters cut more rapidly than the gauge cutters, all of `which tends to throw the tool of! balance, often resulting in a crooked hole and the useless expenditure of power in an attempt to rotate the drill to produce a hole.

An object of the present invention is the provision of a drill provided with cross roller cutters and a novel form of gauge cutters, the gauge cutters being so situated, arranged and constructed as to overcome rounding off or attening of teeth.

Another object is the provision of gauge cutters for a bit so arranged and constructed as to relieve stress from the pins carrying said cutters.

Another object is the provision of gauge cutters for a bit wherein the teeth of the gauge cutters are at all times in contact with the formation to be cut.

Another object is the provision of a bit incorporating gauge cutters which will readily cut the formation by providing a greater cutting edge than normally present in the well known type of gauge cutters.

Another object is the provision of a bit having gauge cutters so situated and arranged as to center the bit during rotation thereof.

Another object is the provision of gauge cutters for a bit wherein the gauge cutters are readily assembled or disassembled from the bit body.

Other objects of the invention will become apparent to those skilled in the art to which this invention appertans, among which objects are simplicity of structure, inexpensiveness in cost of manufacture, and general superiority to gauge cutters now incorporated in cross roller bits.

`With the above mentioned and'other objects in View, the invention consists in the novel andl useiul 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 claim.

In the drawing:

(Cl. Z-'11) Figure 1 is Figure 2 is Figure l, and,

Figure 3 is a fragmentary sectional view on the line 3-3 of Figure 2.

Referring now to the drawing, the improved bit includes a body I provided with the usual pin 2, whereby it may be connected to the drill string. The body is recessed inwardly from the bottom, as shown at 3, to provide two diametrically opposed arms 4 and 5. A bent pin 6 extends between the arms and is secured thereto in any manner, such as by the welding shown at 1 and 8 for each arm. The pin carries cross roller cutters 9 and I0, the cutters being separated at their inner ends by a spacer member I I carried by the pin. Asis usual practice. the cutter I0 is of greater length than the cutter 9. The usual ball .bearings or rollers I2 and I3 are provided between each cutter and the pin. The character of the teeth on the cross rollers is not important to this invention, although I prefer to use teeth of the character shown in my co-pending application for Cross roller bits, Serial No. 431,408, led February 18, 1942.

As has previously been stated, instead of using an ordinary type of gauge cutter, I incorporate in the present bit construction gauge cutters of the type shown in the nated as entireties as I4. Two of said gauge cutters are provided, being diametrically disposed and in a plane at right angles to the axes of the pin 6. The gauge cutter I4 has a tapered body l5, the surface of which is provided with teeth IB of the type described in my co-pending application heretofore referred to. Briey, the teeth of said co-pending application are arranged in staggered relationship on the body I5, which is to say that one set of teeth I1 extends semi-cirvcumferentially of the body, while a second set I8 is staggered with relation to the set I1 and extends semi-circumferentially of the body, This procedure follows for the remaining sets of teeth on the body. In this construction, it will be observed that the plane of each semi-circumferential set of teeth is substantially at right angles to the axis ofthe cutter body and that each set does not provide what might be termed a lead or pitch."

While I have specically shown the type of teeth referred to on the gauge cutters, still I do not wish to limit the present invention to teeth or' the type specified, as other teeth have been found to operate satisfactorily in the practice of the present invention.

a side elevation of the improved bit, a sectional view on the line 2-2 of drawing and here desig-` The body is provided with a spindle I9, which is formed with a bearing race 20. The bit body I is provided with a bore 2|, screw-threaded at 22 to receive a bearing type nut 23. This nut accommodates rollers 24 adapted to bear against the periphery of 'the spindle and likewise is formed with a race 25 complementary to the race 20, between which

races

20 and 25 are disposed rollers 26 which lock the spindle to the nut. The end of the nut is castellated, as shown at 21.

The body l is provided with a bore 28 threadedl at 29 to receive a pin 30, the pin adaptedto be received between diametrically disposed castellations in the end o1' the nut 23. Thus, when the nut is threaded within the body l and the pin tween being less than 90. The outermost end 3| of each gauge cutter terminates above the plane of the cutter teeth of the cross roller cutters, to the end that said gauge cutters are out of contact with the bottom of the hole being cut.

The operation, uses; and advantages of the invention are as follows:

Reference is made to Figure 2 wherein is depicted the bit in the act of cutting formation, the well hole being indicated at 32. It will be observed that the cross roller cutters for cutting the formation are indicated for the bottom of the well hole at 33. The two gauge cutters have cut the formation slant-wise, as shown at 34. Thus, the ends 3| of the gauge cutters are maintained out of contact with the bottom 33 of the well hole. All of the teeth oi' the gauge cutters are in contact with the slant-wise section 34. In this manner, as the bit is rotated, the cross roller cutters will cut a dlametric hole equal to the diameter of the bottom portion thereof at 33. while the gauge cutters will increase the diameter of the hole to the diameter shown at I2. By having a large number oi' teeth in engagement with the formation t0y sauge the hole, the gauge cutter teeth do not become dulled as rapidly' as in the conventional form o1' gauge cutter.

By inclining the axes of the gauge cutters downwardly, or convergently, the gauge cutters tend to center the bit. Ordinarily, the conventional form of gauge cutters imposes considerable stress upon the pins. In the present instance, the spindles are relieved of undue stress as the bit rotates. The stress on each spindle is communicated through the bali bearings 2B to the nut, and thence to the body l. course, communicated through the spindle to the rollers 2|. As illustrated, each spindle in the present construction is relatively short and, in fact, does not require a long spindle as is sometimes required with the conventional type of gauge cutters now generally employed with cross roller bits.

If for any reason a gauge cutter need be changed, the pin 3|! is removed, which will allow the nut 23 to be unscrewed and the entire cutter in that manner removed. 'I'he rollers 26 are removed irom the nut in the usual manner, to-wit, through a transverse opening, which will permit the spindle to be released from the nut.

I claim:

In bit construction, a body, a gauge cutter comprising a conical portion provided with teeth and a spindle, an annular nut adapted to be threaded within said body, castellated at one end, the said nut and said spindle provided with complementary grooves and ball bearings between said grooves for locking the spindle to the nut, and a pin threaded into the body and engaging the castellations for locking the nut against rotation when threaded to the body.

JOHN T. PHIPPS.

Any side stress is, o! l