Year: 1898

page_text: Date of Application, 11th Aug., 1898-Accepted, 17th Dec., 1898
I, CHARLES ARTHUR ALLISON, of 52, Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by The Jackson Drill and Manufac-
turing Company a corporation organized and doing business under and by
virtue of the laws of the State of Colorado, United States of America, and having
its principal office at Denver, in said State,) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:---
This invention relates to improvements in rock drills and consists of the features,
arrangements and combinations hereinafter described and claimed, all of which
will be fully understood by reference to the accompanying drawing in which is
illustrated an embodiment thereof.
In this drawing
Fig. 1 is a vertical, longitudinal section taken through the drill casing, a
portion of the enclosed parts being shown in elevation.
Fig. 2 is a top view of the improved drill.
Fig. 3 is a section taken on the line x-x, Fig. 1 looking toward the right.
Fig. 4 is a section taken on the line -, Fig. 1 looking toward the left.
Fig. 5 is a section taken on the line z-, Fig. 1 looking toward the right.
Similar reference characters indicating corresponding parts in these views, let
the numeral 5 designate the drill casing in which is located the reciprocating
shaft 6 surrounded by the coil spring 7 whose forward extremity bears against a
collar 8 fast on the shaft, while its opposite extremity engages a tension nut 9
exteriorly threaded to engage interior threads formed on the casing extremity
which is open to receive said nut. This nut is flatened on one side and graduated.
This graduated face is provided with numerals to indicate the power of the blow
which the drill will deliver when the nut is screwed into the casing to the mark
indicated by the numeral. A set screw 4 is screwed into the casing to engage-
ment with the graduated face of the nut for the purpose of locking the latter in
any desired position of adjustment.
The forward head 10 of the casing is attached thereto by a rod 12 and a
screw 13. The rod passes through registering apertures formed in the upper
part of the head and in a lug 5 formed on the top of the casing. The rod is
held in place by nuts screwed upon its threaded extremities. The screw 13
passes through an aperture in the head and is screwed into the adjacent casing
extremity. This screw is held in place by a nut screwed against the head. The
casing head 10 is provided with an interiorly projecting sleeve 10". Between
this sleeve and a collar 14 on the drill shaft is located a buffer spring 15. Jour-
naled in the casing below the drill shaft 6, is a transverse rotatable shaft 16
provided with two cams 17. These cams are located on opposite sides of the

page_text: .
reciprocating shaft and they are adapted to engage the collar 8 thereon as the
shaft 16 is rotated.
Mounted on the rear extremity of the casing is a detachable housing composed
of two parts 18 and 18". These housing parts surround the shaft 6 and enclose
two ratchet collars 19 and 19" respectively. The portion of the shaft which
passes through the ratchet collars is provided with a spiral groove 6" and a
straight groove 6º. The spiral groove is shown in full lines in Fig. 1 and the
straight groove in dotted lines. The ratchet collar 19 is provided with a lug 19°
projecting into the spiral groove of the shaft, while the ratchet collar 19ª is
provided with a lug 19 projecting into the straight groove of the shaft.
Pivotally mounted on the housing parts, and engaging the teeth of each ratchet
collar, are three spring actuated dogs. The dogs engaging the collar 19 are
designated by the reference character A, while those engaging the collar 19" are
designated by the reference character B. The dogs are so arranged with reference
to the toothed periphery of the said collars that while one dog is engaging a
tooth, the other dog is a short distance from a tooth, and the third dog somewhat
farther from the tooth. By reason of this feature, if one tooth breaks, the move-
ment of the shaft will be quickly checked by another tooth, and so on until all
the dogs are broken.
The housing part 18ª extends rearwardly and is recessed to receive a small
gear wheel 20 through which the shaft 6 passes. This gear is splined on the
shaft, whereby the shaft passes freely therethrough longitudinally; the gear,
however, turns with the shaft as the latter is rotated. This gear 20 meshes with
another gear 21 splined on the rear extremity of the feed screw 22 which is
journaled in the casing 5 and engages a nut 23 fast on the guide track 24.
When the feed screw is automatically turned through its engaging nut as far
as it will go, the gear 21 engages a rearward projection 24ª of the guide track,
causing the gear to slide backward, whereby it is disengaged from its meshing
gear 20. The rear extremity of the feed screw is provided with a hand crank 25
which is employed to reverse or move backward the drill casing on the track.
The hand crank may also be employed to turn the screw for the purpose of
moving the casing forward in case it is not desired to operate the feed auto-
matically.
Journaled in the upper half of the casing 5, is a shaft 30 having a hand
crank 31 made fast to one extremity thereof. To this shaft is also made fast a
gear 32 meshing with a pinion 33 on the cam shaft 16 which is also provided with
two fly wheels 34, one being located on each side of the drill casing.
The operation of the drill is as follows: the shaft 30 is rotated by turning the
hand crank 31. This movement rotates the gear 32 which, meshing with the
pinion 33, rotates the cam shaft 16. The rotation of the last named shaft imparts
a corresponding movement to the cams 17, causing them to engage the collar 8
and force the shaft 6 backward compressing the power spring 7 As soon as the
shaft is released, the recoil of the power spring throws the shaft forward bringing
the drilling tool in forcible contact with the rock.
As the shaft 6 is drawn backward, its spiral groove 6" engages the lug 19° on
the ratchet collar 19, causing the drill shaft to make a partial rotation in the
direction indicated by the arrow in Fig. 4, since the dogs A prevent the ratchet
collar from turning in the opposite direction. As the shaft turns, the ratchet
collar 19 is also turned, since the lug 19d on the said collar engages the straight
groove 6 of the shaft; the collar 19, however, does not turn during the back-
ward movement of the shaft. During the forward movement of the shaft, the
latter is locked against rotation in the reverse direction by the engagement of
the lug 19 on the ratchet collar 19ª, with the straight groove of the shaft, since
the dogs B prevent the collar from turning. The collar 19 turns in the direction
indicated by the arrow in Fig. during the forward movement of the shaft, the
collar 19 remaining stationary, since it can only turn when the shaft is turned.
As the drill shaft rotates, the feed screw rotates through the instrumentality of

page_text: the meshing gears 20 and 21. The turning of the feed screw carries the casing
forward by virtue of the engagement of the threads of the screw with the nut 23
on the stationary guide track 24. Just before the feed screw reaches its forward
limit of movement, the projection 24" of the guide track engages the gear 21
and slides it backward sufficiently to tlirow it out of mesh with the gear 20.
This feature prevents the breaking of the parts which otherwise might result, in
case the drill shaft were operated after the feed screw could no longer turn.
The guide track 24 is provided with a depending apertured projection 35 having
two shoulders 35" and 35° located on opposite sides thereof. The lower part 35
of this projection is circular. This projection 35 is fastened to an angle
bracket 36 by means of a bolt 37 passing through registering apertures formed
in the two parts.
This bracket is provided with shoulders 36 and 36° which the
shoulders 35" and 35° are adapted to engage. When the drill is in the upright
position, the shoulders 35" and 36 are in engagement, and the nut is tight on
the bolt 37. When the parts are in this position, the shoulders 35 and 36° are
considerably separated. When the drill shaft has been drawn backward suflì-
ciently to remove the drill tool from the hole in the rock, the drill casing and
track may be tipped to one side for the purpose of exposing the hole in the
rock, by loosening the nut on the bolt 37 and turning the projection 35 on the
bolt as an axle, until the shoulder 35° engages the shoulder 36".
It is evident the cams for operating the reciprocating drill shaft may, if
desired, be placed upon or formed integral with the fly wheels.
In this case,
the collar 8 would be provided with lateral projections passing through the slots
formed in the casing and extending into the path of the cams. In this case the
collar 8 would be loose on the shaft to permit the latter to turn freely therein,
the arrangement, however, being such as to cause the collar and shaft to reci-
procate together; making this change would only require the exercise of ordinary
mechanical skill.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The combination with the drill casing, the reciprocating shaft and the power
spring surrounding the shaft, of a crank shaft journaled in the casing, a gear
fast on the crank shaft, another shaft journaled in the casing, a cam fast on the
last named shaft and adapted to engage a collar on the drill shaft, a pinion fast
on the cam shaft and meshing with the gear on the crank shaft, and fly wheels
mounted on the cam shaft.
2. The combination with the drill casing, the reciprocating drill shaft and the
power spring surrounding the shaft, of a crank shaft journaled in the casing, a
gear fast on the crank shaft another shaft journaled in the casing, a
cam fast on the last named shaft and adapted to engage a collar on the recipro-
cating shaft, a pinion fast on the cam shaft and meshing with the gear on the
crank shaft, a pair of fly wheels mounted on the extremities of the cam shaft, a
feed screw journaled in the casing, a guide track upon which the casing is
mounted, the guide track being provided with a nut which the said screw engages,
means for feeding the casing to keep pace with the movement of the drill into
the rock, said means comprising a gear splined on the drill shaft, another gear
splined on the feed screw and meshing with the gear on the drill shaft, the guide
track being provided with a projection arranged to move the gear on the feed screw
sufficiently to disengage it from the gear on the drill shaft by the time the said
screw has reached its forward limit of movement.
3. The combination of the guide track, the casing movably mounted thercon,
the drill shaft mounted on the casing, means for reciprocating the drill shaft,
means for rotating said shaft, a feed screw journaled in the casing, the guide
track being provided with a nut which the said screw engages, means for feeding
the casing to keep pace with the movement of the drill into the rock, said means

page_text: comprising a gear splined on the drill shaft, another gear splined on the feed
screw and meshing with the gear on the drill shaft, the guide track being pro-
vided with a projection arranged to move the gear on the feed screw sufficiently
to disengage it from the gear on the drill shaft, by the time said screw has
reached its forward limit of movement.
4. The combination with the guide track, the drill casing movably mounted
thereon, the reciprocating shaft and the power spring surrounding the shaft, of
a crank shaft journaled on the casing, a gear fast thereon, another shaft journaled
in the casing, a cam fast thereon and adapted to engage a collar on the drill
shaft, a pinion fast on the cam shaft and meshing with the gear on the crank
shaft, the guide track being provided with an apertured depending shouldered
projection, and an apertured bracket adapted to be bolted to said projection and
provided with shoulders adapted to engage the shoulders of the projection, the
shoulders of the two parts being separated on one side, as and for the purpose
set forth.
5. The combination of the guide track and the drill casing movably mounted
thereon, the said track being provided with an apertured depending shouldered
projection, and an apertured bracket adapted to be bolted to said projection, and
provided with shoulders adapted to engage the shoulders thereof, the shoulders
of the two parts being separated on one side, as and for the purpose set forth.
Dated this 11th day of August 1898.
ALLISON BROS.,
Agents for the Applicant.