US1656296A

US1656296A - Cast drill bit with split-tang element

Info

Publication number: US1656296A
Application number: US180429A
Authority: US
Inventors: George D Shields
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-04-02
Filing date: 1927-04-02
Publication date: 1928-01-17
Anticipated expiration: 1945-01-17

Description

Jan. 17, 1928.

G. D. SHIELDS CAST DRILL BIT WITH SPLIT TANG ELEMENT W w w e 1 w m My if, m. m 2 m W M 4 W a u H W W m ,w, m w \fl- J /fi M ma iw 0v F m a m ,4,

Jan. 17, 1928. 1,656,296

, G. D. SHIELDS CAST DRILL BIT WITH SPLIT TANG ELEMENT Fil 1 1927, 2 Sheets-Sheet 2 I hi QYTOQNEY Patented Jan. 17, 1928.

l ononon n. srrrnnnsor nos anennns, cannronnm.

CAST DRILL BIT WITH SPLIT-TANG ELEMENT.

Application filed April 2,

As a, be inferred from the above title,

' it is an object of this invention to provide means for securing a hard blade or blades, such as may be formed by castmgor by the u subdivision or grinding of a flat stock, for rotation by a drill string, or the hke; and in preference to welding a threaded tang element onto a suitable blade or body, or providing a one-piece tang element with means for its reliable retention upon a shank integral with a drill blade or body, I here n propose to employ a two-plece or otherspllt tang element,--relying elther upon means such as a removable collar or upon an 1nli teri'orly threaded element, such as a tangreceiving box, or upon both to holdthe mentioned parts in their assembled relat1on-.

shi s.

(gther objects of my invention, in which I so may employ either suitably ground sect ons of flat stock (in the case of fish-tall blts) or one-piece castings, from a hard metal as a manganese steel, or the l1ke, and which (always providing a shank integrally or otherwise rigidly connected with blade sections) '1 provide for a downward ire-elation of lubricating liquid either enternally of said shank therethrough, may be least appreciated. the following do, so scri'otion of illustrative embodiments of my invention taken in connection with the ap= pended claims and accompanying drawings,

which a 1 may be referred to-as an elevational view, showing an embodimentof my 1nvention comprising a blade of fish-tail type,--- such as may be formed by casting or by suitably grinding a section of flat stock, too hard for convenient machining, to provide a shank integral with a blade.

Fig. 2 is a vertical sectional view taken substantially as indicated by the line 2-2 of Fig. 1, but showing also the lower end of a box or interiorly threaded retaining elemerit hereinafter referred to as serving both tor a securing and a rotating effect.

Fig. 3 is a horizontal sectional view, taken substantially as indicated by the line 3-3 of Fig. 1. 1

l Fig. 4 is a sectional view, comparable with Fig. 3 but showing a feature of modlfication hereinafter referred to.

Fig. 5 is an elevational view comparablewith Fig. 1, but showing an alternative 1927. Serial No. 1230,429.

form embodyin a star blade cast integral with a hollow s ank.

Fig. 6 is a horizontal section, taken substantially as indicated by the line 6-6 of "star blade,-parts being broken away.

perspective view showing one' Fig. 8 is a completesection of a two-piece tang element, adapted to cooperate with a like tan element in the securing of a cast or other 'lade having a suitable shank, at the lower end oi a dril string (or to any suitable rotary element) provided with a box or female retaining element adapted to hold said tank sections in assembled relationship.

Referring first to the details of that specific embodiment of my inventionillustrated in Figs. 1, 2 and 3, I show a fish-tail blade 11, such as may be formed by suitably grinding a section of flat bar stock, as having an enlargement 13, at or near its upper end,-the enlargement referred to being provided with

beveled surfaces

14, 14, which have an inward inclination same effectively to contact with correspondin ly inclined surfaces, 15 (shcwnaae coni cal) provided in the upper ends of tang sections .16, 16.

Thetang'sections 16, 16 are shown as integral with body sections 17, 17'" and as provided not only with pin threads 18 upon semi-frusto-conical positions thereof but with additional threads 19, in a central region, intermediate between said frusto conical, portions and said body portions, said central region being adapted to carry a locking band or ring 20.

In case the locking element is retained, as above implied, by a. threaded engagement, I consider it best not only to adapt the same to engage threads distinct from those provided upon the pin tive tang sections but also to employ lefthand threads at 19; but it should be under-' stood that, dqoending upon the materials and the use intended, the lockin element 20 may ,either be secured in an a ternative manner or entirely omitted,-rcliance being then placed upon engagement between the two-part tang element and any box, or the like, in which the same maybe recelved, t0

adapting the portions of the respec-.

retain the mentioned parts in their assembled relation'ship,the

body sections

17, 17 beingshown as respectively provided with

deep notches

21, 21, suitably shaped to interfit with and to impart rotation to the ring 2O being optionally provided thereon and the shank 12" being shown as entirely rectangular. The

shanks

12 and 12 are shown as adapted closely to interfit within verticalgrooves 25, provided in the

sections

16, 16 or in corresponding grooves 25", 25", provided in the

tang sections

16, 16*; but may provide in 16, 16 or in 16, 16" additional vertical channels such as are indicated at 24, 24in 'Figs. 1 to 3 inclusive; or, as indicated in the figures last referred to I may rely, for circulation purposes, partially upon

channels

23, 23, out rom the

tang sections

16, 16 and partially upon

supplemental channels

24, 24 out in the shank 12 and/or the blade 11.

Consistently with the foregoing, I show in Figs. 5-8 an alternative form in which a star blade comprising sections 11" integral with a hollow shank 12" (upwardly-terminating in an enlargement 13") is provided with a 2-part tang element comprising sections 16" and 16",no locking rin being employed therewith. In this emb iment of my invention, dispensing with all effort to provide a wedge-fit between correspondingly inclined surfaces (such as the mentioned

surfaces

14, 14, and 15, 15), I employ substantially flat shoulders 14", 14" in engagement with oppositely. dis osed surfaces 15' 15", to prevent longitu inal movement of the tang sections 16", 16" relatively to the shank 12"; and I show the shank 12" as not only cylindrical in form to. adapt the same for engagement by correspondingly curved surfaces 25", within the res ctive tang sections, but as provided wit a longitudinal passage 23", downwardly terminating in'separate openings, 24", for the delivery of a lubricating li uid; and, in this form of my lnvention, eac of the mentioned tang sections may be provided with a body portion 17", 17", having not only an intermediate notch or notches 21" but also two halfnotches 21",mating half-notches bein adapted to cooperate in the engagement 0 alternate blade sections comprisin shoul ders 22", disposed therebetween; and the described parts may be held in their assembled relatioriship, pending the insertion of the describedsectional pin within a suitable box provided on a rotatable element, by'means such as a mere wire 20",.shown as disposed in an out-of-the-way position below the threads 18", 18".

In all forms of my present invention, it will be seen that the respective tang sections 16, 16 (or 16", 16", 16", 16") are provided with oppositely disposed, fiat longitudinal faces 26, (26, 26") in radial planes; and whether or not annular means (such as the locking-element 20 or a drive collar 20 or the mere wire 20") are employed, reliance may be entirely or largely placed upon the clamping effect of a suitable interiorly threaded box 27, or its equivalent (see Fig. 2 only) to hold the mentioned tang sections together, and rigidly to retain b ade sections therebetween, during the rotation of the entire organization, for a drilling efiect.

Although I have described by present invention with particular reference toa well drilling bit,'it Will be understood that the principles thereof are believed to be of somewhat general application to all kinds of tools, as providing means for the securing of cast blades, too hard to be conveniently machined, with a machined tang, suitable for use in imparting rotation thereto; and it should be understood also that various features of my invention might be independently emplo ed, and that numerous modifications additional to those herein suggested might easily be devised by workers skilled in the arts to which this case relates, without the slightest departure from the spirit and scope of my invention, as the same is indicated above and in the following claims.

I claim as my invention:

1. In a drill bit: a blade formed of material too hard for convenient machining and "provided with a shank which has a terminal enlargement; and a sectional tang element provided with meansfor causing said blade to rotate therewith.

2. In a drill bit: a blade formed of a material too hard for convenient machining and provided with a shank which has a terminal enlargement; and a sectional tang element provided with threads and with means for securing said blade to-rotate,-said lastmentioned means com, rising notched body portions integral wit sections of said tang.

3. In a drill bit: a blade formed of a material too hard for convenient machining and provided with a shank which has a terminal enlargement; and a sectional tang element provided with threads and with means for securing said blade to rotate,-annular means being provided, below threads on said tang sections, to hold said sections in assemble relationship. I

4. In a drill bit: a blade formed of a material too hard for convenient machining and provided with a shank which has a terminal enlargement; and a sectional tang element provided with threads and with means for securing said blade to rotate,an intermediate portion of each tang section being provided with additional threads for the reception of a locking-element; and an annular locking-element thereon.

5. In a drill bit: a blade formed of a material too hard for convenient machining and provided with a shank which has a terminal enlargement; and a sectional tang element provided with means for said blade to rotate,-the respective sections of said tang being provided with means permitting a downward circulation of a lubricating liquid therethrough.

6. In a drill bit: a blade formed of a material too hard for convenient machining and provided with a shank which has a terminal enlargement; and a sectional tang element provided With threads and with means for securing said blade to rotate,said shank being provided with means permitting a downward circulation of a lubricating liquid externally thereof.

7. In a drill bit: a blade formed of a material too hard for convenient machining and provided with a shank which has a terminal enlar ement; and a sectional tang element, provi ed with threads and with means for causing said blade to rotate,said bit being provided with means for a downward circulation of a lubricating liquid.

8. In a drill bit: a blade formed of a material too hard for convenient machining and provided with a shank which has a terminal enlargement; and a sectional tang element provided with threads and with means for causing said blade to rotate,-the threads on said tang being engageable by interior threads within a threaded box, for a locking efiect.

9. In a drill bit: a blade formed of a material too hard for convenient machining and provided withv a shank which has a terminal enlargement; and a sectional tang element provided with threads and with means for causing said blade to rotate,-the threads on said tang being engageable by interior threads within a threaded box, for a looking efiect; and additional annular means heing provided to hold the mentioned parts assembled. 4 a

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 19th day of March, 1927.-

GEORGE D. SHIELDS.