Improved Apparatus for Drilling, Boring, Screwing, or Tapping Holes.
Year: 1886

page_text: Date of Application, 22nd Nov., 1886
Complete Left, 20th Aug., 1887
Complete Accepted, 8th Nov., 1887
PROVISIONAL SPECIFICATION.
Improved Apparatus for Drilling, Boring, Screwing, or
Tapping Holes.
I RICHARD HODSON of The Thames Ironworks, Blackwall in the County of
Middlesex, Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in portable machinery for drilling, boring,
scrowing or tapping holes in any material or structures, particularly in the manu-
facture of machinery, iron and steel steam boilers, pontoons and bridgework.
This improved portable drilling and screwing apparatus is fitted with differential
gear,
so as to be used as a power drill with an automatic feed, but is also capable of being
used as a simple drill with a hand feed. The apparatus may be driven by band from
any prime mover, or by hand power, and consists of a compound spindle or drill
holder carrying the band pulley or hand wheel, or a wheel and ratchet lever. The
compound spindle is socketted to receive a drill or other tool at its inner end, while
its outer end enters a pressure cap or bearing, and is supported in any desired
position against the thrust of the feed of the tool by an abutment arm adjustably
attached to a bar clamped to any convenient and adjacent part of the structure or
mechanism. In heavy work, three or more centres can be introduced to take the
pull of the belting or strap on the pulley.
In order to obtain an automatic feed, and to secure an increase of power by driving
the drill or tool through differential gear, I further introduce an arm or stop, which
will tightly embrace the outer flanged tube, the outer end of this arm working freely
up and down against the clamped bar.
The compound spindle is capable of receiving a drill of any required length, the
stem of which passes into, and is secured to the spindle by a set screw near its inner
end, so as to permit of its projecting a shorter or longer distance from the tool holder,
as may be required. This tubular spindle is threaded internally to receive a threaded
hollow pin, the head of which terminates in a centre, and has its bearing, when in
operation, in the cap carried by the abutment arm.-Fitting around the tubular

page_text: •
spindle is a flanged tube carrying at its inner end the first or central spur pinion of
the differential gear, and at its outer end a flange, upon which is mounted a pawl for
feeding the tool forward in the manner to be presently described. To hold the
central spur pinion from rotating, the arm or stop embracing this flanged tube is
made capable of gripping it, while its opposite end slides freely to and fro on the
clamped support or bar. The band pulley turns freely upon the tubular spindle and
flanged tube, and encloses the differential gear. Mounted on a stud pin within this
hollow pulley, is a double pinion, its larger diameter gearing into the stationary
central pinion, and its smaller diameter into a spur wheel keyed upon the tubular
spindle or drill holder. By this arrangement of gear, a power of from 4 to 1, or
more or less, can be obtained for the operation of drilling or tapping holes, but other
proportions of differential gear may be adopted and used in duplicate, if necessary, as
may be desired, for the work in hand.
The automatic feed of the tool is obtained by the partial rotation of the internally
threaded tubular spindle, as a nut upon the threaded pressure pin. On the upper
surface of the flanged tube is mounted a spring pawl, which is held out of action by
the flange of the tubular spindle, except where an indent is made, or portions of the
flange are removed to allow the pawl to fall in, and lock the flanged tube carrying
the stationary pinion to a ratchet wheel lying loosely upon the flange of the tubular
spindle, but connected to the threaded pressure pin by a feather and groove con-
nection, thereby holding the ratchet wheel and threaded pressure pin from rotating.
The rotation of the threaded tubular spindle will therefore give the necessary feed
motion to the drill, until the pawl is lifted out by the passage of the larger diameter
of the flange past it. A cap or hand wheel may form a cover to this ratchet and pawl
mechanism, and serve to actuate the feed by hand when the apparatus is used as a
simple drill, suitable locking pins being provided to lock the pawl and differential
gear out of action.
When it is required to drill holes through a second plate at some distance from the
first, the drill may be loosened from its holder by unscrewing the set screw, and
withdrawing its stem from the interior of the hollow pressure pin, until the drill rests
against the second surface to be operated on, when it can be again secured, and the
operation recommenced.-When tapping holes, the threading tool is provided with a
long stem to enter the hollow pressure pin. This stem is grooved to receive the point
of the set screw, which then acts as a feather and groove connection between the
tubular spindle and the tapping tool. A helical spring, or some other elastic medium,
is placed between the outer end of the tap and pressure pin, so as to ensure an elastic
pressure on the tap as it screws itself into the plate. The amount of feed per rotation
of the drill may be regulated by the length of the indents in the disc, or by providing
two or more indents.
The drill can be instantly stopped working without throwing the strap or cord off
the pulley, or stopping the engine, by releasing the grip of the lever or stop on the
outer flanged tube, so as to allow it to rotate instead of the tubular spindle or drill
holder. To reverse the motion of the apparatus so as to unscrew a tapping tool, it
will only be necessary to stop the working of the differential or other gear by means
of a screw or stop the direction of motion of the band pulley may then be reversed,
together with the tool, at quick speed.
Dated this 22nd day of November 1886.

page_text: Improved Apparatus for Drilling, Boring, Screwing, or
Tapping Holes.
I RICHARD HODSON of The Thames Ironworks, Blackwall, in the County of
Middlesex, Civil Engineer do hereby declare the nature of this invention 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 portable apparatus for drilling, boring,
screwing, or tapping holes in metal and other materials, which apparatus is
particularly useful in manufacturing machinery, iron and steel steam boilers, ships,
pontoons, and bridgework.
This improved portable drilling and screwing apparatus I preferably fit with
differential gear, so that it may be used as a power drill with an automatic feed, but
it is also capable of being used as a simple drill with a hand feed.
In the accompanying drawings,
Fig. 1 is a side elevation of the drilling apparatus complete.
Fig. 2 is a vertical section taken through the line 1, 2 of Fig. 1, and looking in the
direction of the arrow.
Fig. 3 is a sectional plan view, taken in the line 3, 4 of Fig. 1, of the drilling
apparatus; and
Figs. 4 and 5 are detached views of parts of the drill hereafter specially referred to.
In these Figures, A A¹ is a compound spindle or tool holder, A being the holder,
to which the drill B is made fast by a locking pin. The holder A is threaded
internally to receive the thread of the screwed spindle A¹, which is preferably mado
hollow to receive the stem of the drill or other tool.
The drill spindle A' is connected to a head C₁ carried by an abutment arm C,
which is itself supported by, and capable of adjustment on a round drill post D.—
The upper end of the screwed spindle enters a cup bearing in the head C¹, and it is
formed with an annular indentation to permit of its being coupled to the head C¹ by
means of a Ushaped staple c passed through the sides of the cup.-Fitted to the drill
holder A is a flanged sleeve E, which is held fast by a metal clip F carrying a
bracket arm F¹, that enters a slotted guide formed in the head C.-This clamp is
made fast to the sleeve E by a screw bolt f, and the bracket arm F¹ is capable of
being secured to the head C, to maintain the drill holder A in its set position, when
the operation of tapping is to be carried out.-G is a band pulley divided horizontally
at its centre to form a case for the reception of differential gearing. The lower half
of this pulley is mounted loosely on the drill holder A, and the upper half, which is
divided into two to facilitate its displacement and replacement, is secured to the lower
half by screws.
In
Keyed to the drill holder is a central pinion 1, and set above this pinion, and
keyed to the sleeve E, or formed therewith, is a pinion 2, of smaller diameter.
gear with these pinions are two corresponding pinions 3. 4, cast in one, and fitted
loosely on a stud carried by the pulley G, the pinion 3 gearing into the pinion 1, and
the pinion 4 into the pinion 2.
By the rotation of the pulley G, rotary motion is communicated to the drill holder
by reason of the pinion 2 acting as a fulcrum over which the pinion 4 rolls, thus
causing the rotation of the pinion 3, which being in gear with the pinion 1, imparts
rotary motion to the drill holder A.

page_text: For heavy work, it may be found desirable to duplicate the pinions 3 and 4,
mounting them on a second stud pin carried by the pulley G, and situate diametrically
opposite to the first mentioned stud pin.
In order to change the speed of the tool holder relatively to the pulley G, the
differential gearing may be changed as desired.
The feed of the drill B is effected in the following manner :-Keyed to the upper
end of the tool holder A (see Figs. 2, 4, and 5), is a notched ring a, which carries
a second notched ring a¹ adjustable thereon, but made fast thereto for the purpose to
be presently explained.-Situate above these notched rings, and connected to the
screwed spindle A¹, is a ratchet. wheel a², which is free to slide up and down the
screwed spindle; while it prevents that spindle from rotating.-a³ is a spring pawl
taking into the teeth of the ratchet wheel a², and thus locking it in position. This
pawl is pivotted upon a flange of the sleeve E, and is formed at its head with a
pendent projection that bears against a cam lever a pivotted on the under side of the
flange of the sleeve.
The concentric parts and pawl just described are hidden in Fig. 1 by a divided
cover A2, which overlies those parts, and interlocks, by means of pins, with the
ratchet wheel a².-The cover is made slightly conical to receive a hand wheel A³,
which, when dropped upon it, will hold the divided cover securely in place. The
use of this contrivance is to enable the attendant to move the ratchet wheel by hand,
and impart the requisite feed to the drill, irrespective of the automatic device.-It
will, however, be evident that the mere connection of the cover with the ratchet wheel
will not interfere with its action as an automatic feeder.-The cam lever a* is intended,
by pressing on the projection of the pawl a³, to throw it out of contact with its ratchet
wheel. While the pawl is engaged with the ratchet wheel, the tool holder A will, as
the pulley G is driven, slowly advance the drill to its work, but on the tripping of
the pawl the feed will cease. This tripping of the pawl is effected by hand through the
cam lever a. For automatically tripping the pawl during the operation of feeding,
the notched rings a a¹ are used, but the feeding is also stopped automatically when
the sleeve is released by the slackening of the screw bolt in the clamp F. When
this is effected, the sleeve will be left free to rotate with the lever a.-The effect of
this rotation of the sleeve is to bring the tail of the cam lever into contact with the
bracket arm F¹, whereby the cam lever is turned on its axis, and caused to press the
pawl out of gear.
The better to understand the construction and action of the device for effecting
the automatic feed, reference is made to Figs. 4 and 5, which are sectional plan
views, the one shewing the ratchet wheel a² in place, and connected by a feather to
the screwed spindle A, and the other shewing the ratchet wheel removed, the better
to exhibit the notched rings a and a carried by the tool holder.-These Figures show
also the pawl a³ which gears with the ratchet wheel a' for the purpose of retaining it
in a quiescent position, and with it the screwed spindle A-While the ratchet wheel
is thus locked, the notches of the rings a a¹ are in coincidence with the head of the
pawl, and the feed is consequently taking place.-The continued rotation, however,
of the tool holder A, will cause its rings a a¹ to push back the pawl clear of the
ratchet wheel, and thereby to stop the feed. The screwed spindle will then rotate
with the holder, and continue so to do until the notches of the rings come again into
coincidence with the head of the pawl.-The ratchet wheel will then be locked as
before the screwed spindle A' will cease to rotate, while the continued rotation of
the tool holder will, through its connection with the screwed spindle, impart a fresh
feed to the drill.
It will be obvious that a double set of notches may be formed on the rings a a¹ to
allow of the pawl engaging twice with the ratchet wheel during one rotation of the
tool holder, thereby quickening the feed.
Thus, at the completion of every rotation, or partial rotation, as may be arranged
for, of the tool holder, a fresh feed will take place.
By providing two notched rings a a', which are adjustable relatively to each other,
the notch into which the head of the pawl falls, may be lengthened or shortened at

page_text: will, thereby increasing or diminishing the amount of feed given to the drill.―The
adjustment of the upper ring on the lower one is effected by slackening a screw
which holds them together, and giving an axial motion to the upper ring, so as to
contract or lengthen the notch.-This setting is then secured by tightening up the
coupling screw.
When it is desired to stop the action of the drill, it will only be necessary to
slacken the screw bolt of the clamp F.-The sleeve E will thus be left free to rotate,
and the pinion which it carries thereby losing its function of a fulcrum, will impart
no motion to the travelling pinion 3, and consequently no driving of the tool holder
will take place.
Referring now to Fig. 1, it will be seen that the drill post D is formed with a
slotted foot D¹-This is to facilitate its attachment, by means of a bolt and nut, to,
say, a boiler plate, or other piece of work on which the drill is intended to operate.-
The abutment arm C is hinged to a socket piece C³, which fits on to the top of the
post, and is adjustable thereon by means of a screw C³, which enters a screwed
socket in the post, and by means of collars, is permanently secured to the socket
piece C-The head of the screw is squared to receive a key for adjusting the socket
piece C.
I have said that the drill spindle is attached to the adjustable head C¹ of the
abutment arm. In order to present the drill properly to an inclined piece of work
without shifting the position of the post, the abutment arm is made adjustable to any
desired angle from the horizontal. This is illustrated by the dotted lines in Fig. 1,
and to sustain the abutment arm in its adjusted position, a strut C is provided.-
This strut is pivotted to the abutment arm, and also to a clamp D³, which is adjustable
on the post D, and made fast thereto by a clamping screw. Besides this, the
socketted head is capable of swivelling upon the abutment arm, so as to give the
drilling apparatus any desired lateral movement within limited range, and it may
also be adjusted to and from the post by slackening its binding screw, the arm being
made cylindrical to provide for these adjustments.-The bearing cup which receives
the end of the screwed spindle A' is pierced at its centre to allow of the introduction
of a lubricant thereto.
The apparatus as above described illustrates only its use as a drill, but it is equally
servicable for tapping drilled holes. Besides this, it is specially advantageous for
drilling and tapping holes in two thicknesses of metal secured together, but fixed at
some inches apart. This application of the invention is illustrated at Fig. 1, where
the drill having been passed through one thickness of metal, is adjusted to operate
upon the second thickness.-These two thicknesses of metal may represent respec-
tively, say,
the shell of a boiler and the combustion chamber or tube plate.-By this
peculiar arrangement of drill, the second hole can be drilled without moving the top
centre or arm supporting it, or without changing the drill for one with a longer
stem. This is due to the screwed spindle which acts as the feeding pin being bored
through the greater part of its length to receive the stem of the drill, thus making a
kind of telescopic arrangement which will allow the tool to be drawn out from the
tool holder, and fixed thereto at any desired point. Supposing the tool to have drilled
a hole through the shell plate, and that it is required to drill one through the com-
bustion chamber six inches distant therefrom, on the completion of the first drilled
hole, the tool is drawn out from the holder to reach the second plate. It is then
made fast to its holder by the locking pin, and the operation of drilling is proceeded
with as before.
For tapping holes, it is only necessary to replace the drill by a tap having a long
back end or stem, so that the telescopic arrangement may be used, but instead of the
tap being made a fixture vertically in the tool holder, as with the drill, it is allowed
to pass freely up and down in the telescopic arrangement, but forced to rotate by
means of a feather in the tool holder working in a slot cut vertically in the back end
or stem of the tap.-This arrangement is not shown in the drawing, but its construc-
tion will be obvious to any competent mechanic. At starting, the tap is placed in
the hole to be threaded, and the apparatus is kept in a fixed position relatively to the

page_text: arm of the post, by the bracket arm F¹ of the clamp F being made fast to the socket
head C. A gentle downward pressure is put upon the tap by a coiled spring inserted
in the screwed spindle in rear of the tap stem, but when the operation of tapping has
fairly commenced, the tap will run itself completely through the drilled plate by the
driving power given to the pulley G.
At Figs. 6, 7, and 8, I have shown an arrangement of band pulleys suitable for
transmitting motion from a stationary prime mover to the band pulley G of the drill
when shifted from place to place.
Fig. 6 is a plan view.
Fig. 7 an elevation of one end of the band pulley arrangement, and
Fig. 8 a side view of the other end of the mechanism.
G is the band pulley of the drill, and H is the band pulley from which the motion
is derived. The band from this pulley passes over a guide pulley I to the apparatus
to be driven. This guide pulley I, together with a second guide pulley I', is carried
on the frame of a yoke K, suspended from a fixed point in the workshop.―This yoke
serves also to carry a balanced rod K¹, which is fitted with a guide pulley L situate
near the pulley G.-Connected with the frame of the yoke is a counter weighted
chain M, laid over a fixed pulley N, for the purpose to be presently explained. The
driving band from the pulley H passing over the pulley I, goes thence to the
pulley G, and from it to the pulley L; after lapping around this pulley, it is
crossed, taken over the opposite side of the pulley G to that which it first touched,
then back to the pulley I¹, and so to the driving pulley H.-The rod K' is arranged
to slide, if required, in the yoke K, to adjust the position of the pulloy L, and the
tension of the counterweighted chain serves to put a strain upon the whole length
of the driving band, and keep it in good frictional contact with the pulleys G
and H.
It is evident that as the rod K¹ with its pulley L is free to turn under the point
of suspension; the pulley G of the portable drill can be worked in a variety of
positions without the re-arrangement of the driving gear.-One such changed
position is illustrated by the dotted lines in Fig. 6.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. The arrangement of portable drilling and tapping apparatus as above described
and illustrated in the drawings.
2. The compound drill spindle or holder fitted with a feeding device, as described,
for imparting an automatic or a hand feed to the drill.
3. The means above described for transmitting motion from the pulley G to the
tool holder.
4. The means above described for converting the drilling or boring apparatus into
a screw tapping machine.
5. The means above described for adjusting the position of the tool without
changing the position of the post.
6. The telescopic arrangement whereby the drill can be drawn out from the holder,
and the tool lengthened or shortened, without moving the drilling apparatus.
7. The arrangement for stopping the action of the drill without stopping the
driving gear.
Dated this 16th day of August 1887