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Jan. 20, 1931.
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L. c. BAYLES
1,789,359
CENTRALI-ZER FOR DRILL STEELS
Fileddune 23, 1928
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INVENTO-R.
(113a Zed
Iii/5’ ATTORNEY.
Patented
Jan.
20,
1931
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*UNITED STATES ‘ PATENT ' OFFICE
LEWIS c. BAYLES, or‘ EAS'I‘ON, rENNsYLvnivia, Ass'renonuro IivGEnsoLL-nAnn coiu- _
PAN'Y, or JERSEY CITY, NEW JERSEY,A‘COBJ?ORATIO1\I on NEW ‘JERSEY,
CENTRALIZER FOR jDRI-LL ‘STEELS
Application-?led June 23, 1928. Serial No. ‘287,766.
1 This invention relates to rock drills, but.
more particularly to
centralizer for the
working implement, such as a drill steel
adapted to be actuated by rock drills of the
5 hammer type.
,plicity of illustration, but it is 'to' be under
stood that-‘suitable elements, such asguides ~
(not shown) on the‘rock drill, of which the
front head is a part, may interlock with the
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 implementvE 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 align- end into the front head D to receive the blows
10 men’; with the rock drill.
of a hammer piston (not, shown) ‘of the drill.‘ 55
Another object is to enable the centralizer
to be readily rocked out of the operative position by means of the rock drill after the
drilling operation reaches a point in which
15 the guiding function of-a centralizer is no
longer essential.
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Other objects will be in part obvious and
in part pointed out hereinafter, and to all of
these ends the invention consists of the fea20 tures of construction and arrangement of
In certain drilling operations it is at times
a matter of considerable-difliculty to maintain
the drill bit coaxial with the rock drill, par
ticularly when the rock drill lies in a hori
Zontal position or. in positions, approaching '60
the horizontal; Aftera certain period of
usage ‘wear is caused in the chuck parts of
' the rock drill-and as a consequence the, drill
steel tends to inc-line from the axis of the
rock drill. When operating under these con- .65
parts having the general mode of operation ditions the drill bit will swing about the de
substantially 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 in
drawings, in which
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tended course.
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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,
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have been substituted for the starting drill.
Figure 2 is an enlarged longitudinal sec
.
If their the position of the drill is not changed
'30 tional; elevation of the centralizer and a por- to coincide with the course of the drill hole 75
tion‘ of the shell taken through ‘Figure 3 on the'drill steel will bind in the drill hole and
the line 2—2 looking in the direction indi» will greatly hinder the rotation of the drill
cated by the arrows, and
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Figure 3 is a transverse sectional elevation
-35 of the centralizer taken through Figure 1 on
the line 3—3 looking in the direction indi, cated by the arrows.
Referring more particularly to the drawings, A represents a rock drill shell having
4 O a conical projection B whereby the shell may
_ steel. 7 As a result of such binding of the drill
steel the drilling e?iciency will be consider
ably lowered, the drill bit will require more 80
frequent- sharpening‘ and it will also be more’
difficult; to ‘maintain thelgauge of the drill
bit than would be the case if. the drill bit
were maintained in axial alignment with the
rock drill. -.
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be secured to a support for holding the shell ' 1 The present invention aims to eliminate
in ?xed 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.
‘ “front head- D is shown. for .thesake; of sim- The centralize!‘;Flcomprises a yoke-Gyms; O
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1,789,859
arms H of which are suitably spaced to re
In order to assure against movement of
ceive the body portion of the drill steel E. the drill steel in the direction of the open end
Preferably a U-shaped bushing J is dis— of the yoke G a pin d may be inserted in ap
posed in the yoke G to act as a wearing sur ertures c in the arms H of the yoke and said
face for the yoke, so that any wear ‘which apertures e are preferably so located that 70
may be caused by the drill steel E will be the pin d may bear lightly against the sur
con?ned to the comparatively inexpensive
bushing J and which bushing may be readily V
face of the drill steel E.
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In the operation of the device, whenever
and cheaply replaced whenever it becomes it is desired to start a new drill hole the cen
tralizer 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
ceptionof a pivot pin Parranged transverse the longitudinal axis of the front head D.
to and off-set with respect to the axis of the In this position of the centralizer the plung
drill steel for which the yoke forms a‘guide er» Y will bear against the ?at surface Z and
so that the said yoke will rock through'a will be held in engagement therewith by the
un?t 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 re
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plane extending through the axis of the drill pressure exerted by the spring 6, it being as
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steel. The relative proportions of the aper sumed of course that the spring I) is capable
ture O and the pivot pin P are preferably of exerting a su?icient pressure to hold the
such that the yoke G may rock freely on the centralizer F in this position unaffected by
the vibration set up in the rock drill. As the
pin P.
The pivot pin P is seated with its ends into front head D approaches the centralizer F
bearing blocks Q arranged on opposite sides the pin d may be withdrawn from the aper
of the transverse portion L. The bearing ture e and as the drill advances toward the
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blocks Q therefore lie in the same transverse rock C the front head D will strike the cen
plane as the stem K and have apertures B tralizer F and will rock it to the inoperative
through which extend bolts S whereby the position wherein it will be held by the spring
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bearing blocks Q, are secured directly to the pressed plunger Y.
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By means of vthis invention the front or
front end of the shell A.
If desired, or whenever the centralizer F free end of the drill steel may at all times be
is applied to certain types of shells, spacers T held coaxial with the rock drill so that when
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may be interposed between the bearing blocks the bit end ofthe steel encounters abnor
Q, and the end of the shell to avoid contact malities in the rock being drilled the steel
between the centralizer and such adjuncts as will be held against departure from the de
may protrude beyond the end of the shell, sired course. This is particularly desirable
100
as for instance, a feed screw bearing U which and advantageous in drilling operations
forms a support for a feed screw V whereby wherein it is essential that the holes be
the rock drill is actuated longitudinally of drilled parallel to each other, as for instance
the shell. In order to maintain the pin P where the line of cut or drilling is later trav
stationary in the bearing blocks Q, pins W ersed by a broaching mechanism for remov
are disposed in the bearing blocks Q, to ex ing ‘the material‘ between adjacent drill
' tend through the pivot pin P, thus holding holes.
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said pivot pin P both against rotary and
I claim:
longitudinal movement relatively to the hear
1. A centralizer for drill steels, compris
ing blocks Q.
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ing a yoke for guiding a drill‘ steel, astem on
the yoke having an aperture, a pair of bear
ing unauthorized movement of the yoke G ing blocks adapted to be secured directly to
out of the operative position. To this end the end of a rock drill shell and disposed on
the stem K is provided with an aperture X opposite sides of the stem, a pin seated ?x
for the reception of a plunger Y having a edly in the bearing blocks and extending
flat end Y’ adapted to seat on a flat surface through the aperture to form a pivotal sup
Z of the pin P. A spring 6 is disposed in the port for the yoke, a ?at surface on the pin,
aperture X rearwardly of the plunger Y to and a spring pressed plunger in the stem
Suitable means are provided for prevent
120
exert a pressure on said plunger tending to having a flat end to seat on the ?at surface
hold it ?rmly against the‘ flat surface Z. If for normally holding the yoke against move
desired a similar flat surface 0 may be ment with respect to the pin.
2. A centralizer for drill steels, compris
formed on the forward surface of the pin
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P to act as a seat for the plunger Y so that ing a yoke for guiding a drill steel, a stem on 125
when the yoke G is rocked out of the opera the yoke having an aperture, a pair of bear
tive or guiding position, said plunger may ing blocks secured directly to the end of a
cooperate with the flat surface 0 for main
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rock drill shell and lying in the same trans
ing the yoke in the inoperative position in— verse plane as the yoke, a pin seated ?x
edly in the bearing blocks and extending
dicated by dot and dash lines in Figure 1.
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‘1,789,8
through the aperture to form a pivotal sup
port 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
10 it is actuated.
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In testimony whereof I have signed this
speci?cation.
LEWIS C. BAYLES. I
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