US1510222A - Expansion percussion bit for drilling or boring operations - Google Patents

Description

Sept. 36, 1924. 15%,222

\ J. H. HERMAN EXPANSION PERCUSSION-BIT FOR DRILLING OR BORING OPERATIONS Filed July 9. 1920 s sheets-shear. l

H W WIN Sept. 30, 1924. 15161222 .J. H. HERMAN EXPANSION PERCUSSION BIT FOR DRILLING OR BORING OPERATIONS rlled' duly 9. 1920 s Sheets-Sheet 2 Sept; 30, 1924.. 11,510,222

J.H.HERMAN EXPANSION PERCUSSION BIT 'FO R DRILLING 0R BORING OPERATIONS Filed July 1920 3 Sheets-Sheet 5 Patented Sept. 30, 1924,

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J'O' HN' HENRY HERMAN, OF MELBOURNE, AUSTRALIA.

Application filed July 9,

To all whom it may concern: v

Be it known that I, JOHN HENRY HER- MAN, a citizen of the United States of America, and resident of Melbourne, Victoria, Australia, have invented certain'new and useful Improvements in Expansion Percussion Bits for Drilling or Boring Operations, of which the following is a description.

This invention relates to an improved under-reaming percussion bit for drilling, or boring operations and refers especially to a bit for boring or drilling a hole of enlarged diameter in deep well operations such as oil or artesian bores.

In deep well bores as at present operated it is customary to drill for a certain distance with a hole of the same diameter as the inside of the casing and to then withdraw the bit and use an under-reaming bit to enlarge the hole to the diameter of the outside of the casing so that the casing may be lowered to the extent of another length or section. 1

The object of this invention is to providea. drillin bit whereby a hole of the diameter of t e outside of the casing, may be drilled in the one operation thereby effecting 'a. great saving in time, labor and power.

I accomplish this object by providing a drilling bit having two cutting edges one of which is located above the other and is arranged to cut away the sides of the bore formed by the lower cutting edge and. a pivoted trigger member adapted to bear against the sides of the bore below the casing and cause the bit to operate eccentrically whereby the upper cutting edge will enlarge the diameter of the hole cut by the lower cutting edge of the bit.

In order that the invention may be readily understood reference will now behad to the accompanying sheets of explanatory draw-- ings wherein j Figure 1 is a viewin side elevation of a percussion bit constructed in accordance with the present invention showing it in its raised position and within the casing of a bore, part of the bore and easing being broken away for convenience of illustration.

Figure 2 is a view similar to Figure 1-.

. quite smoothly.

1920. Serial N0. 395,069.

showing the percussion bit at the bottom of its stroke and thrust to one side of the bore.

Figure 3 is a. view in elevation of the percussion bit shown in Figures 1 and 2 and 55 drawn to a. larger scale.

Figure 4 is a view in side elevation of the percussion bit showing part broken away to clearly illustrate the pivoted trigger member and method of attaching it to the bit.

' Figures 5 to 8 illustrate details in the construction of the trigger mechanism and hereinafter will be fully described.

Figure 9 is a. view in inverted plan of the cutting edges of the percussionbit shown in Figures 3 and 4. r

In these drawings the letter a designates the hit which is formed with the screw shank Z; on the upper end set to one side of the centre and the lower end oi. the bit 79 is provided with two cutting edges, a narrow central edge 0 and abroad lateral edge d one of which is disposed above theother.

The lower cutting edge 0 extends from the side of the bit nearest the axis of the screw shank to a point beyond the centre of the bit and is narrower than the upper cutting edge (Z which extends from a point in line with the inner corner of the lower cutting edge a to the side of the bit farthest from 80 th'e'axis of the said bit.

lhe lower cutting edge 0 is adapted to form the well bore e and the upper cutter d is designed to cut to the outside diameter of the casing and thoroughly pulverize the material in the hole being formed (see Figure 2 of the drawings). The part of the bit above the lower cutting edge 0 1s made narrow to provide clearance for the' material cut away in the drilling o eratlon ea and the upper cutting part is made roader and conforms to the shape of the periphery of the casing f to ensure the sides of the enlarged part of the bore being finished The side of the bit in line with and'at. a suitable distance above the lower cutting edge a is formed with arecess 9 in which is pivoted a trigger member h whichis normally pressed outward by means of a Spring 1% i. 'The trigger member is curved on its underside and the recess is so shaped that the trigger member will move inwardly and outward y without leaving an opening through which dust and dirt can enter the said recess and so interfere with the operation of the said trigger member. The upper end of the trigger member h is pivoted on a pin j passing through the upper end of the recess in the bit and the said member is shapedso that it will swing outwardly beyond the side of the bit and inward into the said recess. An outward pressure is maintained on the trigger member h by means of the compression spring i which I exerts a thrust on a tappet is having one end ivotally connected to the said trigger mem er below the pivot point thereof.

The outer face of the trigger member can be fitted with a removable shoe h which can be readily removed when worn and replaced by a new one thus obviating the oxpense of fitting a new trigger member.

In order to ensure the bit passing freely into the 'top of the casing in a bore, the pivoted trigger member 71- is forced into therecess 9 until it is flush with the side of the bit when the said bit may be passed freely into and down through the casing (see Figure 1). When the bit has passed through the casing the pivoted trigger member h is forced outward by the action of the spring a and the shoe h thereon is caused to bear against the side of the enlarged part of the bore 6 as shown in Figure 2. The

' pressure of the trigger member against the side of the bore causes the bit to be operated eccentrically whereby the upper cutting ed ge d will enlarge the diameter of the bore cut by the lower cutting edge a. lVhen the bit is drawn upwardly prior to partially turuing and again dropping the same the trigger member It will be forced into the recess when.

it strikes against the bottom of the casing.

The trigger member is moved outward by its spring directly the bit passes through the basing on its next downward stroke and bears against the side of the well here farthest from the under reaming cutting edge d thereby causing the said cutting edge to bite into the side of the bore and enlarge the same.

The thrust of the trigger member against the side of the well bore causes the bit to operate more or less eccentrically accordingto the distance to which the said trigger member is set to moveobeyond the side of the recess in the bit, and-Tthe manner in which the bit is caused to operate by. the

action of the said member as clearly shown in Figures 1 and 2 of the drawings.

The trigger member bears against the side of the bore when the cutting edges of the bit strike the bottom thereof and prevents any vibration likely to be set up in the bit and stem due to any side thruster canting of the said bit when the broad cutting edge thereof strikes the opposite side of the bore in performing the under-reaming operation.

The absence of vibration due to the above mentioned causes ensures the drill working quite smoothly and prevents the stems or joints of the tools being subjected to undue stress or jar.

I claim: a

1. In a percussion bit for drilling and boring operations, a bit body having a lower narrow cutting edge and a second broader cutting edge spaced above the lower edge and offset laterally therefrom, said bit body provided in one side adjacent to the narrow cutting edge with a narrow deep recess, a bearing member Inovably fitting within the recess, a pivot carried by the bit body and engaging through the upper end portion of said movable member and adapted to receive thrust thereof when extended, and a horizontally arranged spring seated in the body 2. A percussion bit for drilling or boring operations comprising an elongated bit body having longitudinally spaced apart cutting edges on its lower end with the upper-cutting edge offset laterallyoutward from the lower cutting edge, and a pressure member pivotally mounted in the side of said bit body adjacent to the lower cutting edge, said pressure member having an arcuate outer edge adapted to lie closely to the inner wall of the bit body and to prevent accumulations of foreign substances beneath the member when open, and means for yieldingly urging said pressure member outwardwhereby sald member is adapted to swing outwardly through the side of the bit body upon passage thereof beyond the extremity of a casing. I

3. A percussion bit for drilling and bormg operations comprising a bit body provided at one side with relatively stepped cutting edges, a segmental ressure member pivoted within the other si e of said b1t body and in spaced gelation to said lower end thereof, a springttrranged horizontally in said bit body with one end thereagainst and its other end against said segmental pressure member whereby to normally urge the latter into an outward position, the pivotal axis of said pressure 'memberbeing arranged substantially in the horizontal plane of the polnt of contact between the pressure mem .er and the side of the well bore, whereby pressure position under pressure,

exerted against said ressure member is transmitted substantial y in a straight line to said pivotal axis for maintaining said segmental member in an outwardly extending adapted to withstand shocks of ercussion ineident to impacting said bit he y.

said spring being In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribin witnesses.

" JOHN HENR HERMAN.

Witnesses:

01m A. HAon, G. R. GULLEN.

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