IMPROVEMENTS IN SUPPORTS FOR ROCK DRILLS
Year: 1885

page_text: COMPLETE SPECIFICATION.
I ALFRED JULIUS BOULT of 323 High Holborn in the county of Middlesex,
Engineer do hereby declare the nature of this invention for "IMPROVEMENTS IN
SUPPORTS FOR ROCK DRILLS" (a communication from Charles Seymour Westbrook,
of Spragueville, New York, United States of America, Gentleman) and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement reference being had to the accompanying
Drawings which form a part of this Specification and in which :-
Figure 1 represents a perspective view of this improved support for rock drills.
Figure 2 is a cross section of the cradle, or drill rest, removed from the tripod.
Figure 3 is a sectional view of the saddle with its bearings.
Figure 4 is a similar view of one of the extensible legs of the tripod.
Figure 5 is a sectional detail view of part of the same: and
Figure 6 is a detail view of the several parts of the device for locking the legs
of the tripod against the sides of the saddle.
Figure 7 is a detail view of the washer.
Similar letters of reference indicate corresponding parts in all the figures.
This Invention has relation to the support or bearing for rock drills, and is
applicable to drills operated by steam, compressed air, or any other suitable
medium, and of any desired construction. The object of this improvement is, first,
to compensate for wear of the ways or guides in the cradle, in which the drill
works; secondly, to compensate for wear at the point where the legs of the tripod
are connected to the saddle which supports the cradle; thirdly, to provide means
whereby the several parts of the tripod may be locked or fastened together after
they have been properly adjusted, so as to avoid accidental displacement of the .
drill; and fourthly, to avoid the labor, expense and loss of time incident to re-
tapping of the extensible legs, which form the tripod, when the set-screws become
worn.
In the accompanying drawing, A denotes the cradle or carriage in which the
drill (not shown in the drawing) works. This cradle has the usual extension, A¹,
in which the feed-screw works, by means of which the drill is fed forward as it
·

page_text: progresses into the rock. The cradle has, on one side, a groove, B, preferably of a
V-shape in cross-section, and on the other side a flat-topped projection, C, having
a series of oblong, transverse slots, D, through which nutted bolts, d, are inserted,
by means of which the plate, E, is fastened, adjustably, to the part, C. This plate
is beveled on one side, as shown at e, so as to form, with the part, C, a guide-
groove or way, B¹, corresponding to the parallel groove, B, on the other side of the
cradle.
The laterally projecting part, C, has a flange, c, on the outside, between which
and the adjacent side of the adjustable guide-plate, E, a wedge-shaped key, F, is
inserted, and held in place by a plate, f, fastened upon the part, C, so as to overlap
the key.
The parallel ways, B and B¹, receive the flanges or projections on the body of
the drill, and as these ways become worn, wear may be taken up or compensated
for by driving in the key or wedge, F, which can be done in a moment of time and
without stopping the operation of the drill. This prevents lost motion and cause
the drill to work absolutely true at all times.
The saddle, G, which supports the cradle, has the usual extensible side-legs, HH,
and the back-leg, I, which form the tripod. The latter carries at its upper end the
'yoke or fork, J; the two ends of which form collars, K, which bear against the
sides, g, of the saddle, and are clamped against them by the hips, H'H', of the
side-legs, H. Said hips, H', have projections, h, which fit inside of the collars, and
are perforated centrally for the insertion of a bolt, L, the inner end of which fits
into a boro or recess, l, in the sides, g, of the saddle, and is held therein by a key, M.
Placed upon the projecting outer ends of each of the two side bolts or
trunnions, L, is a washer, M, of peculiar construction. This washer consists of a
plate, with a central hole for the insertion of the bolt, and having on one side two
projections, nn, forming inclined planes on opposite sides of the bolt-hole, and
bearing with the said inclined planes against a key, C, which is inserted trans-
versely through the head of the trunnion-bolt, L, and held in place therein by a
key, P, and gib, p, which is, in turn, held in place by a set-screw, Q, working
in a screw-threaded bore, g, centrally in the trunnion-bolts, L.
It follows that by turning the disks or washers, N, upon their bolts, L, so as to
wedge their inclines, n, against the sides of the keys, P, bearing against them, the
several connecting parts of the saddle and tripod will be locked together by
friction, and thus prevent slipping or displacement of the legs after these have
once been properly adjusted. As the inclined planes on the washer-plates point
in opposite directions on opposite sides of the saddle, it follows that one of them
will bind them when the other loosens, and vice versa, like the nuts upon a right-
and-left-hand threaded screw, so that the hips will always bind firmly against the
saddle; and if it is desired to release the parts from their locked position, all that is
necessary is to loosen the keys, which gives play to the several connecting parts of
the saddle and tripod, so that they may readily be moved and their relative
position changed. The plates or washers, N, also operate to take up wear between
the saddle and its adjacent parts as their wedges or inclines can always and readily
be so adjusted as to tie the several parts together and compensate for wear.
The extensible or telescopic legs consists, each, of a solid upper part which is
screwed into the hip, and a lower tubular part, 8, having a pointed shoe at its
lower end. The upper end of the tube, S, has a square aperture, t, cut through
one side, adapted to fit an ordinary nut, T, and covered on the outside by a band
or collar, s, through which the set-screw or bolt, U, is inserted, with its inner end
working through the removable nut, T, against the solid upper part of the leg..
By making the lower part of the extensible legs tubular, instead of the upper
part, as usual in tripods for rock-drills, the set-screw, U, is placed near the upper
end of the leg, or at some distance from its lower end, so as not to be affected by
the dirt and debris which accumulates around the tripod in working the drill;
and which, by getting into the threads of the screw, or bolt, is apt to render its
operation difficult, When the threads in the nut wear out, a new nut can readily

page_text: be substituted, thus avoiding retapping, as when the screw-threads are cut in the
walls of the tube, and the cost, labor and delay incident to the cutting of new
threads. By carrying a few extra nuts and bolts in his pocket, the workman
operating the drill can always renew an old and worn-out nut and bolt when
necessary, without having to remove the drill from the place where it is in use.
Having now particularly described and ascertained the nature of this Invention,
and in what manner the same is to be performed I declare that what I claim is
First. In a support for rock-drills, the combination of the cradle or carriage
baving a fixed guide-groove on one side; a parallel guide-plate fastened adjustably
on the opposite side of the cradle; and means, substantially as described, for
adjusting the movable guide-plate; substantially as and for the purpose set forth.
Second. The combination, in a support for rock-drills, of a cradle having a
fixed guide-groove on one side and a parallel flanged projection on the opposite
side; a guide-plate fastened movably upon the flanged projection; and a key or
wedge inserted between the movable plate and the flange of the fixed projection;
substantially as and for the purpose set forth.
Third. The combination of the saddle, the trunnion-bolts, the keys for fixing the
same in the sides of the saddle, the collared yoke or fork of the back-leg, the hips
of the side-legs having projections fitting into said collars, the plates or washers
working upon the trunnion-bolts and having inclined planes arranged as described,
and the keys against which said inclined planes bear; substantially as and for the
purpose herein shown and set forth.
Fourth. The combination, with the saddle and tripod, of the plates or washers
having inclined planes aanrrged as described, and the keys, with their appropriate
gibs and set-screws, whereby said keys may be locked against the inclines of the
washers; substantially as and for the purpose shown and set forth.
Fifth. The combination of the tubular leg-section having a recess in one side
adapted to fit a nut, the solid leg-section sliding in the tubular section, the set-
screw or bolt and the removable nut inserted into the recess in the tubular section;
substantially as and for the purpose herein shown and described.
Dated this 17th day of February 1885.
ALFRED J. BOULT.