Improvements in Portable Pneumatic Drills and similar Tools.
Year: 1899

page_text: Date of Application, 1st Aug., 1899-Accepted, 17th Feb., 1900
COMPLETE SPECIFICATION.
Improvements in Portable Pneumatic Drills and similar Tools.
I, HENRY JAMES KIMMAN, of 1235, Lawndale Avenue, Chicago, Cook County,
Illinois, United States of America, Machinist, 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:-
My invention has reference to improvements in pneumatic drills and the like
and consists chiefly in the provision in a portable pneumatic drill of a throttle or
main controlling valve by which the operation of the drill can be reversed. In
carrying out this leading feature of the invention certain improvements have been
made in the air passages leading to the pivotal cylinder valves and in the cylinder
valves themselves which are arranged to act as inlet and exhaust, as more fully
described hereinafter.
In the accompanying drawings Figure 1 is a vertical longitudinal sectional
elevation Figures 2 and 3 plan sectional views, taken on lines 2 and 3 of
Figure 1; Figure 4 a longitudinal sectional view of a portion of the machine,
taken on the line 4 of Figure 3; Figure 5 a transverse sectional view, taken on
the line 5 of Figure 1; Figure 6 a transverse sectional view, taken on the line 6
of Figure 1; and Figure 7 a longitudinal sectional view of a portion of the
throttle or main controlling valve.
In constructing a portable pneumatic drill in accordance with my improvements,
a main casing is provided and preferably made in three parts, a base plate A, and
intermediate casing A¹ and a cap A2. These parts in plan contour resemble an
isosceles triangle, and are made of the desired size and strength to hold and
maintain the operating parts in their desired relations.
An operating shaft B is provided and has one bearing in the base of the casing,
and its other bearings 6' in a lower cap B¹ which is secured to the base plate by
means of the screws 62. To rotate this operating shaft, a crank shaft C is provided
which has for its bearings arranged in the upper and lower parts of the main
casing and is provided with a spur pinion e which is attached to the lower end
thereof and which meshes or engages with a spur gear 3 on the operating shaft, so
that as the crank shaft rotates the operating shaft is also operated,
To operate the crank shaft in either direction, or, in other words to provide a
reversible pneumatic drill, two oscillating cylinders D and D¹ are provided and
pivotally mounted upon pivotal valves d and d. Each of the oscillating cylinders
is provided with reciprocating pistons D2 and D3, which have their piston rods d
and projecting out therefrom and engaging with the crank on the crank shaft.
It will be observed from the above description and from the arrangement of
mechanisms as shown in Figure 3 that the impulse on the crank shaft is inter-
mittent, that is, the pistons act on the said shaft alternately.
In order to supply fluid under pressure to the oscillating cylinders at the desired
time or times, the pivotal valves dd' are made of the usual hollow type, but are,
according to my invention, provided with a pair of passages d' and d. These
passages are provided with two transverse outlets arranged to be brought into
alignment with the passages de in the oscillating cylinders, so that pressure may
be admitted to or exhausted from such cvlinders at the proper time or times. In
order to admit fluid under pressure to the pivotal valves dd. the upper cap of
the main casing is provided with two sets of passages E E', E³, E³, arranged

page_text: in pairs, and which connect with the longitudinal passages in the pivotal
valves d d by means of the transverse openings e e¹, e² and e
In order to control the admission and exhaust of the fluid 'under pressure, so as
to rotate the crank shaft in either direction, a main controlling or throttle valve
is provided which has a tapered plug G having its seat in a bushing in the cap of
the main casing and which is provided with a longitudinal and transverse inlet
passage g and exhaust passages gl and g². The bushing G¹ in which this tapered
plug is seated is provided with four transverse openings g³ adapted to register
with the transverse openings or passages in the said plug.
To rotate the tapered plug of the main valve so as to supply fluid under pressure
to the oscillating cylinders and rotate the crank shaft in either direction and to cut
off the same, a handle H is provided and oscillatingly mounted on a hub h of the
main casing cap on the outside thereof. A flanged plug or nut h' assists to main-
tain this handle in its desired position and is also provided with a main inlet H',
through which the fluid under pressure is admitted to the longitudinal inlet
opening of the main valve plug. A pin 2 is inserted in the handle portion and
passed through a segmental slot in the hub of the cap and valve seat and
engages with the tapered plug of the main valve so as to partially rotate the
same by means of the handle whenever desired, all of which will more fully here-
inafter appear.
In operation, assuming the controlling throttle valve to be in the position
shown in Figure 2, fluid under pressure passes through the main cap down
through the inlet opening. g of the tapered plug of the main valve into the
passages E and E2 of the casing cap. The pressure continuing flows through
the passage d of the pivotal valve d out through the passage de
into the pressure cylinder D to force its piston forwardly and assist
in rotating the crank shaft. At the same time the oscillating cylinders D)¹
is in such position that the further admission of fluid pressure has stopped. The
further rotation of the crank shaft carries the parts to such position that the fluid
under pressure passes out through its passage do, through the exhaust passage d'
of the pivotal valve, thence through the passage 13 in the casing cap or
passage g in the tapered plug of the main valve, and out through the opening g
in the valve casing. The crank shaft continuing its rotations the oscillating
cylinder D¹ is oscillated so as to shut off the exhaust and bring its passage into
alignment with the transverse passage of the inlet passage in the pivotal
valve d¹ so as to admit a supply of fluid pressure from the supply channel ². At
the same time, the oscillating cylinder I) has been carried into such position that
its passage is brought into alignment with the exhaust passages d, e, E, g¹, g²,
to be exhausted into the open air.
If it is desired to reverse the rotation of the crank shaft and the operating shaft,
the handle H of the drill is rotated so that its pin 2 is brought to the opposite
position to that shown in Figure 5. This brings the passages in the tapered plug
of the main valve one-fourth of the way around, so that what were the exhaust
passages in the pivotal valves described during the previous operation now
become the inlet ports, and what were described as the inlet passages in the fore-
going operation now become the exhaust passages, thus permitting the parts to
· be rotated in a reverse direction.
1
Although I have shown in the drawings and referred in the specification to a
drill having only two oscillating cylinders and my improved reversing valves
operating in connection with the said two oscillating cylinders, yet my new or
improved valves are equally operative with a double set of oscillating cylinders,
that is, four in all, the second set being immediately below the first, the pivotal
cylinder valves being of course prolonged to go through both sets.
The principal advantage due to a machine constructed in accordance with my
improvements is that one tool may be used for drilling or tapping holes in either
direction-in other words, the operating shaft can be rotated in a right and left
hand manner.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I wish it to be dis-
tinctly understood that I do not claim the general components of a pneumatic
drill, such as a cylinder and a piston, neither do I claim broadly vertical pivotal
cylinder valves, but what I do claim is:-
1. In pneumatic drills or the like, a reversing throttle valve such as y sub-
stantially as described with reference to the drawings annexed and for the purpose
specified.
2. In pneumatic drills or the like, fixed pivotal valves said valves each having
two ports or passages adapted to act as inlet or exhaust passages for pressure to and
from the cylinders and operating substantially as described with reference to the
accompanying drawings and for the purpose specified.
3. In pneumatic drills or the like, the combination of a reversing throttle valve,
passages (such as E, E¹, E², 13) in the drill casing or framework each passage
adapted to act as inlet or exhaust for pressure to and from the cylinders, and fixed
pivotal cylinder valves each having two ports each of said ports being adapted to
act as inlet to or exhaust from the cylinder, the whole operating substantially
as herein described for the purpose specified and as illustrated in the drawings
annexed.
Dated this 1st day of August 1800
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.,
Agent for Applicant,
70 & 71, Palace Chambers, Westminster, S.W.