US1789859A - Centralizer for drill steels - Google Patents

Description

Jan. 20, 1931. L. c. BAYLES 8 CENTRALI-ZER FOR DRILL STEELS Fileddune 23, 1928 g INVENTO-R.

Iii/5 ATTORNEY.

. lie-um (113a Zed i v Patented Jan. 20, 1931 r V e v P i *UNITED STATES PATENT OFFICE LEWIS c. BAYLES, or EAS'ION, rENNsYLvnivia, Ass'renon ro IivGEnsoLL-nAnn co u- PAN'Y, or JERSEY CITY, NEW JERSEY,ACOBJ?ORATIO1\I on NEW JERSEY,

CENTRALIZER FOR DRI-LL STEELS Application-filed June 23, 1928. Serial No. 287,766.

1 This invention relates to rock drills, but. plicity of illustration, but it is 'to' be undermore particularly to centralizer for the stood that-suitable elements, such asguides working implement, such as a drill steel (not shown) on therock drill, of which the adapted to be actuated by rock drills of the front head is a part, may interlock with the 5 hammer type. V shell A in a wellknown manner to enable the 50 One object of the invention is to guide and rock drill to travel longitudinally of the shell support the overhanging portion of the drill A. A .working implement E illustrated as a steel so that in' starting a drill hole the bit drill steel extends with its rearward or shank of the drill steel will be held in axial alignend into the front head D to receive the blows ith th k d ill. of a hammer piston (not shown) of the drill. 55

Another object is to enable the centralizer In certain drilling operations it is at times to be readily rocked out of the operative poa matter of considerable-difliculty to maintain sition by means of the rock drill after the the drill bit coaxial with the rock drill, pardrilling operation reaches a point in which ticularly when the rock drill lies in a horithe guiding function of-a centralizer is no Zontal position or in positions, approaching '60 longer essential. the horizontal; Aftera certain period of Other objects will be in part obvious and usage wear is caused in the chuck parts of in part pointed out hereinafter, and to all of the rock drill-and as a consequence the, drill these ends the invention consists of the feasteel tends to inc-line from the axis of the tures of construction and arrangement of rock drill. When operating under these con- .65 parts having the general mode of operation ditions the drill bit will swing about the desubstantially as hereinafter described and sired axis in starting a new drill hole and as claimed and illustrated in the accompanying a result the hole may incline from the indrawings, in which tended course. r 1 Figure 1 is a longitudinal side elevation of Frequently the foregoing conditions are l 70 the front end of a rock drill and its shell not detected until a certain depth has been showing the manner in which thefree end drilled or until drill steels of greaterlength of the drill steel is guided, have been substituted for the starting drill. Figure 2 is an enlarged longitudinal sec If their the position of the drill is not changed tional; elevation of the centralizer and a porto coincide with the course of the drill hole 7 tion of the shell taken through Figure 3 on the'drill steel will bind in the drill hole and the line 22 looking in the direction indi will greatly hinder the rotation of the drill cated by the arrows, and 4 steel. 7 As a result of such binding of the drill Figure 3 is a transverse sectional elevation steel the drilling efliciency will be considerof the centralizer taken through Figure 1 on ably lowered, the drill bit will require more front head- D is shown. for .thesake; of sim- The centralize! F comprises a yoke-G ms the line 33 looking in the direction indifrequentsharpening and it will also be more cated by the arrows. difficult; to maintain thelgauge of the drill Referring more particularly to the drawbit than would be the case if. the drill bit ings, A represents a rock drill shell having were maintained in axial alignment with the a conical projection B whereby the shell may rock drill. be secured to a support for holding the shell 1 The present invention aims to eliminate in fixed position with respect toa working the foregoing described undesirable features surface, such as the rock designated-byC, and to this end the rock drill is provided 1 In the drawings only the front end of a a with a centralizer designated generally by F.

arms H of which are suitably spaced to receive the body portion of the drill steel E. Preferably a U-shaped bushing J is dis posed in the yoke G to act as a wearing surface for the yoke, so that any wear which may be caused by the drill steel E will be confined to the comparatively inexpensive bushing J and which bushing may be readily V and cheaply replaced whenever it becomes unfit for the intended purpose.

In the construction shown the yoke G is provided with an integral stem K having at its lowermost end a transverse portionL in which is formed an aperture 0 for the receptionof a pivot pin Parranged transverse to and off-set with respect to the axis of the drill steel for which the yoke forms aguide so that the said yoke will rock through'a plane extending through the axis of the drill steel. The relative proportions of the aperture O and the pivot pin P are preferably such that the yoke G may rock freely on the pin P.

The pivot pin P is seated with its ends into bearing blocks Q arranged on opposite sides of the transverse portion L. The bearing blocks Q therefore lie in the same transverse plane as the stem K and have apertures B through which extend bolts S whereby the bearing blocks Q, are secured directly to the front end of the shell A.

If desired, or whenever the centralizer F is applied to certain types of shells, spacers T may be interposed between the bearing blocks Q, and the end of the shell to avoid contact between the centralizer and such adjuncts as may protrude beyond the end of the shell,

as for instance, a feed screw bearing U which forms a support for a feed screw V whereby the rock drill is actuated longitudinally of the shell. In order to maintain the pin P stationary in the bearing blocks Q, pins W are disposed in the bearing blocks Q, to extend through the pivot pin P, thus holding said pivot pin P both against rotary and longitudinal movement relatively to the hearing blocks Q.

Suitable means are provided for preventing unauthorized movement of the yoke G out of the operative position. To this end the stem K is provided with an aperture X for the reception of a plunger Y having a flat end Y adapted to seat on a flat surface Z of the pin P. A spring 6 is disposed in the aperture X rearwardly of the plunger Y to exert a pressure on said plunger tending to hold it firmly against the flat surface Z. If desired a similar flat surface 0 may be formed on the forward surface of the pin P to act as a seat for the plunger Y so that when the yoke G is rocked out of the operative or guiding position, said plunger may cooperate with the flat surface 0 for maining the yoke in the inoperative position in dicated by dot and dash lines in Figure 1.

In order to assure against movement of the drill steel in the direction of the open end of the yoke G a pin d may be inserted in apertures c in the arms H of the yoke and said apertures e are preferably so located that the pin d may bear lightly against the surface of the drill steel E. V

In the operation of the device, whenever it is desired to start a new drill hole the centralizer F may be rocked to the operative position, thatis, to a position in which it lies perpendicular to the drill steel E. The pin d may then be inserted in the apertures e to maintain the drill steel E in alignment with the longitudinal axis of the front head D. In this position of the centralizer the plunger Y will bear against the fiat surface Z and will be held in engagement therewith by the pressure exerted by the spring 6, it being assumed of course that the spring I) is capable of exerting a suflicient pressure to hold the centralizer F in this position unaffected by the vibration set up in the rock drill. As the front head D approaches the centralizer F the pin d may be withdrawn from the aperture e and as the drill advances toward the rock C the front head D will strike the centralizer F and will rock it to the inoperative position wherein it will be held by the spring pressed plunger Y.

By means of this invention the front or free end of the drill steel may at all times be held coaxial with the rock drill so that when the bit end ofthe steel encounters abnormalities in the rock being drilled the steel will be held against departure from the desired course. This is particularly desirable and advantageous in drilling operations wherein it is essential that the holes be drilled parallel to each other, as for instance where the line of cut or drilling is later traversed by a broaching mechanism for removing the material between adjacent drill holes.

I claim:

1. A centralizer for drill steels, comprising a yoke for guiding a drill steel, astem on the yoke having an aperture, a pair of bearing blocks adapted to be secured directly to the end of a rock drill shell and disposed on opposite sides of the stem, a pin seated fixedly in the bearing blocks and extending through the aperture to form a pivotal support for the yoke, a fiat surface on the pin, and a spring pressed plunger in the stem having a flat end to seat on the flat surface for normally holding the yoke against movement with respect to the pin.

2. A centralizer for drill steels, comprising a yoke for guiding a drill steel, a stem on the yoke having an aperture, a pair of bearing blocks secured directly to the end of a rock drill shell and lying in the same transverse plane as the yoke, a pin seated fixedly in the bearing blocks and extending through the aperture to form a pivotal support for the yoke, a flat surface on the pin, a spring pressed plunger in the stem seating on the flat surface to normally hold the yoke against movement with respect tothe pin, a U-shaped bushing in the yoke forming a bearing surface for the drill steel, and a pin insertable in the yoke for maintaining the drill steel coaxial with a rock drill whereby it is actuated.

In testimony whereof I have signed this specification.

LEWIS C. BAYLES. I

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