Improvements in Portable Drilling Machines and in Means for Driving the same.
Year: 1889

page_text: Date of Application, 8th Apr., 1889
Complete Specification Left, 8th Jan., 1890-Accepted, 8th Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in Portable Drilling Machines and in Means for
Driving the same.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the City of
London, Civil Engineer and Patent Agent, do hereby declare the nature of this
invention (a communication to me from abroad from James Taggart Halsey, of
132, Nassau Street, in the City, County and State of New York, United States of
America, Engineer) to be as follows :-
This invention relates to that class of drilling machines, commonly called portable
drills, which are adapted to be shifted about and used in any part of the workshop;
such machines being usually driven from an overhead shaft by a rope-belt, the length
of which is varied as occasion may require.
In a machine made in accordance with the present invention, the automatic feed
mechanism, whereby the drill or bit is fed up to the work at an uniform rate, and
the means whereby the base of the machine is removably secured to the template or
"jig" used in the work, are constructed as under :-The drill, tool or bit is held in a
socket in the end of a bar or holder, which is of uniform size throughout its length
and preferably cylindrical. The drill-bar or -holder carries a sleeve provided with a
clamping screw. A male screw on the sleeve engages with a female screw in the
boss of a bevel-wheel-nut rotating on the face of a larger bevel-wheel to which it is
held up by suitable clips. The larger bevel-wheel has a tubular boss through which
the drill-holder or -bar plays endwise the bar rotating with the said wheel by reason
of a spline in the eye of the wheel playing in a longitudinal groove in the bar.
The tubular boss of the wheel has a bearing in the hollow base or frame of the
machine. A bracket on the said frame carries a tubular shaft arranged radially with
respect to the drill-holder and having a driving pulley and a bevel-pinion which
gears with the larger bevel-wheel. The axial rotation of the drill is effected by this
shaft. The latter encloses an inner shaft, the two shafts being clamped together .at
will by any suitable coupling device. On the end of the inner shaft is mounted, a
bevel-wheel or -pinion which gears with the upper bevel-wheel-nut before referred to.
The inner shaft effects the feeding of the drill.
The operation of the feed is differential in principle, the smaller bevel-wheel,
which is, in fact, a nut on the feed-screw, being rotated by means of the inner feed-
shaft and its bevel pinion in the same direction as that in which the drill is rotated by
means of the tubular shaft and its bevel-pinion; but, inasmuch as the nut is rotated
at a less speci than the drill, it follows that the drill is gradually fed up to its
work. The difference in speed is effected by duly proportioning the gear-wheels
and-pinions. For example, if the bevel-wheel-nut makes twenty-four revolutions whilst
the bevel-wheel which rotates the drill makes twenty-five revolutions, the drill will
be advanced a distance equal to the pitch of the feed-screw on the sleeve at each
twenty-five revolutions of the drill. The advantage in making the screw-threaded
sleeve independent of the drill-bar or -holder is that, whilst the machine is secured to
the template, the sleeve may be unclamped and the bar and drill drawn out from
above; and, by reason of the tubular driving shaft and the inner shaft being made
separable, the drill may be quickly run back or withdrawn from the hole by simply
reversing the motion.
For the purpose of securely fixing the machine to a jig or template, its base is
provided with a tubular nipple through which the drill plays; the nipple being
provided with a male screw for screwing into a female screw in the template.
the base of the machine may have a flange which may be fastened to the template by
means of carews or bolts
Or,

page_text: “
Inasmuch as the drill may be required for use in any part of a large workshop, and
with its axis either vertical, horizontal, or inclined, a belt-device of the kind generally
known as a
rope-hanger is employed for communicating the necessary driving
power. It is desirable that the endless driving belt or strap should be circular in
cross section. As the drilling machine will sometimes be situated near to an some-
times distant from the driving shaft, the rope-guide in the swivel bracket carrying
the guide-pulley is left open in such a manner that endless belts of different lengths
may be employed, according to the distance from the driving shaft at which the drill
is to be used. In order that the belt-device may be employed in workshops with
comparatively low ceilings, the pulleys are so arranged that a part of the endless
driving rope may be double roved, so that the weight which takes up the slack will
not have so far to move.
G. G. M. HARDINGHAM.
COMPLETE SPECIFICATION.
Improvements in Portable Drilling Machines and in Mears for
Driving the same.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the City of
London, Civil Engineer and Patent Agent, do hereby declare the nature of this
invention (a communication to me from abroad from James Taggart Halsey, of
132, Nassau Street, in the City, County and State of New York, United States of
America, Engineer) and in what manner the same is to be performed to be particu-
larly described and ascertained in and by the following statement:
-
This invention relates to that class of drilling machines, commonly called portable
drills, which are adapted to be shifted about and used in any part of the workshop ;
such machines being usually driven from an overhead shaft by a rope-belt, the length
of which is varied as occasion may require.
In the accompanying drawings, Fig. 1 represents in vertical section a drill made in
accordance with the present improvements; Fig. 1 being an end view of the clutch-
slide, and Fig. 1 a section on the line 1 1, Fig. 1. Fig. 2 is a plan corresponding
with Fig. 1 Figs. 3 and 4 being horizontal sections on the lines 3-3 and 4-4
(Fig. 1) respectively. Fig. 5 is a similar view to Fig. 1 shewing a modified form of
construction.
с
The automatic feed-mechanism, whereby the drill or bit is fed up to the work at an
uniform rate, and the means whereby the base of the machine is removably secured to
the template or "jig," are constructed as under :-The drill, tool or bit, X, is held in
a socket in the end of a bar or holder A, which is of uniform size throughout its length
and preferably cylindrical. The drill-bar or -holder carries a sleeve A¹ provided with
a clamping screw a. A male screw on the sleeve engages with a female screw in the
boss of a bevel-wheel-nut B rotating on the face of a larger bevel-wheel C, to which
it is held up by suitable clips. The bevel-wheel C has a tubular boss c through
which the drill-holder or -bar A plays endwise; the bar rotating with the wheel by
reason of a spline or feather c¹ in the boss of the wheel playing in a longitudinal
groove a in the bar. The tubular boss c has a bearing in the hollow base or frame D
of the machine, and is kept in place by the nut c². A bracket E on the frame carries
a tubular shaft F, arranged radially with respect to the drill-holder A and having at
one end a driving pulley G, and at the other end a bevel-pinion c, which gears with
the bevel-wheel C. The axial rotation of the drill X is effected by this shaft. The
latter encloses an inner shaft H; the two shafts being clamped together at will by any
suitable coupling device. The particular device for this purpose shewn in the
drawings consists of a clutch-slide I, provided with one or more teeth or projections i,
which engage in corresponding recesses or notches in the end of the tubular shaft F.
The slide I is caused to rotate with the shaft H by a transverse bar, each end of
which plays within one of the slots jj in the shaft H. These slots are long enough to

page_text: llow the slide to be drawn back until the teeth are free of the notches in the tubular
shaft F. To keep the parts in engagement, a spring k, which bears against the bar,
is inserted in the hollow projecting extremity of the shaft H. The slots jj are wide
enough to allow the slide I, when drawn back out of engage nent with the shaft F, to
be partially rotated about the common axis of the shafts F and H, so that the teeth i
may be thrown out of register with the notches in the shaft F, in which position of
the parts the two shafts F and H remain out of engagement. On the end of the
inner shaft H is mounted a bevel-pinion B', for driving the bevel-wheel-nut B. The
shaft H effects the feeding of the drill. The bracket E is furnished with a split band e
by means of which it is attached to the neck of the frame D. The band e is
provided with a clamping screw e, whereby the bracket may be secured in any
desired position. The rotation of the bracket does not interfere with the proper
engagement of the driving pinions B and C with the driven wheels B and C, as the
parts are arranged concentrically.
The operation of the feed is differential in principle, the bevel-wheel B, which is in
fact a nut on the feed-screw of the holder A, being rotated by means of the feed-
shaft H and its bevel-pinion B' in the same direction as that in which the drill X is
rotated by means of the tubular shaft F and its bevel-pinion C₁; but, inasmuch as
the nut B is rotated at a less speed than the drill, it follows that the drill is gradually
fed up to its work. The difference in speed is effected by duly proportioning the
bevel-wheels and pinions and C and B and B¹. For example, if the nut B makes
twenty-four revolutions whilst the bevel-wheel C makes twenty-five revolutions, the
drill will be advanced a distance equal to the pitch of the feed-screw on the sleeve at
each twenty-five revolutions of the drill. In order to steady and guide the drill, I
prefer to provide the tubular nipple or nut (hereinafter described) with a removable
bush K having a bore corresponding with the diameter of the drill. Where drills of
different sizes are used, separate bushes to correspond are employed.
For the purpose of securely fixing the machine to the jig or template J', its base
is provided with a tubular nipple J; the nipple being formed with a male screw for
screwing into a female screw in the template. Or, the base of the machine may be
flanged and fastened to the template by means of screws or bolts.
In Fig. 5, a single shaft F H is shown instead of the two shafts F and H. The
sleeve A is dispensed with; the male screw, corresponding with the female screw of
the nut B, being cut on an enlarged portion of the holder A. The bracket E' is
represented as forming a solid part of the base or frame D.
An advantage in employing two shafts F and H capable of moving independently
is that the drill may be quickly run back or withdrawn from the hole by simply
rotating one of the shafts in the reverse direction. The use of the screw-threaded
sleeve A is to allow the bar A and drill X to be drawn out from above without
being rotated. The movable bracket E, shewn in Figs. 1 and 4, permits the position
of the driving pulley G to be easily altered after the machine has been fixed to the
template.
Inasmuch as the drill may be required for use in any part of a large workshop
and with its axis either vertical, horizontal or inclined, a belt-device of the kind
generally known as a "rope-hanger is employed for communicating the necessary
driving power.
"
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :-
1. The improved portable drilling machine constructed substantially as herein
described, and adapted for being readily secured to the work to be drilled, and for
being easily adjusted to suit the lead of the driving rope.
2. In a portable drilling machine, the combination, with a base-piece (D) and a
driver for the holder (A) rotating therein, of the holder (A) mounted in the driver
and provided with a feed-screw, a feed-nut embracing the feed-screw, and gearing
driven from a common source for rotating the driver and feed-nut simultaneously

page_text: -in-the same direction but..at different speeds, substantially as and for the purpose
described.
3. The employment in a portable drilling machine of the kind herein described, of
a bearing bracket (E) carrying the driving shafts (F and H) (or shaft FH) and
provided with a band (e) which embraces the neck of the hase-piece (D) and.is
tightened by a clamping screw (el), substantially as and for the purpose.described.
4. In a portable drilling machine, the combination, with a base-piece (D) and a
driver for the holler (A) mounted rotatively therein, of the holder (A) provided with
a feed-screw, a feed-nut. embracing the feed-screw, a toothed wheel (1) forming part
of the nut, a toothed wheel (C) forming part of the driver, driving pinions (B and C)
gearing with the wheels respectively, pinion-shafts (H and F) arranged one within
the other, a driving sheave (G) keyed on the exterior shaft, and a clutch for connecting
the shafts when they are to be driven in unison instead of independently, substantially
as and for the purpose described.
5. A portable drilling machine having a base-piece (D) provided with an. aperture
for the passage of the drill and with a tubular nipple or male screw (J) for securing
the drill in the proper position for drilling, the drill passing through the nipple or
screw, substantially as herein described.
6. The combination, with a portable drilling machine having a base-piece or stock
provided with a tubular nipple or male screw (J) for securing the drill to a template,
of a template provided with a female screw to receive the tubular male screw, the
latter embracing the drill and centreing it, substantially as and for the purpose
described.
Dated this 8th day of January 1890.
G. G. M. HARDINGHAM.