Improvements in Pneumatic Drills and the like.
Year: 1899

page_text: Date of Application, 16th Nov., 1899-Accepted, 10th Mar., 1900
COMPLETE SPECIFICATION.
Improvements in Pneumatic Drills and the like.
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:-
The object of my invention is to provide a simple, economical and efficient pneu-
matic drill and the invention consists in the features, combinations and details
of construction hereinafter described and claimed.
In the accompanying drawings, Figure 1 is an elevation of an engine constructed
in accordance with my improvements showing all of the operative parts inclosed
and protected from external influences; Fig. 2 a transverse sectional view taken
on line 2 of Fig. 1; Fig. 3 a similar view, taken on line 3 of Fig. 1; Fig. 4 a
longitudinal sectional view, taken on line 4 of Fig. 3; Fig. 5 a sectional view,
taken on line 5 of Figs. 6, 9, and 10; Fig. 6 a view of the end ported plate of the
drill with the rotating disc valve located thereon; Fig. 7 a similar view with the
rotating disc removed; Fig. 8. a view of the inner side of the rotating disc valve;
Figs. 9 and 10 transverse sectional elevations, taken on lines 9 and 10 of Fig. 5;
Fig. 11 an end view of the drill casing and crank shaft, with the cap and ported
plate removed; Figs. 12 and 13 transverse sectional views, taken on lines 12 and 13,
respectively, of Fig. 4; Fig. 14 a side elevation of the crank shaft; and Figs. 15, 16,
17 and 18 details views of the connecting rod end and connecting rod hereinafter
described.
In constructing a pneumatic drill in accordance with my improvements, I make
a casing A, of the desired size shape and strength to support, contain and enclose
all of the operative parts of the drill and efficiently protect the same from exterior
influences, such as dust, dirt, and the like. This casing is provided with six
cylindrical pressure chambers a', a², a³, at, a³, and a, arranged in two sets of
three each occupying different planes with regard to the rotation of the crank
shaft. Each cylinder is preferably arranged at an angle of about 120 degrees from
each other cylinder in the set, and is provided with reciprocating pistons A1, A2,
A3, A4, A5, and A. A crank shaft B is provided, having two crank portions b
and 2 arranged at 180 degrees, or diametrically opposite to each other, to which
the connecting rod ends a, a, a, a, all and a¹ of each of the pistons are con-
nected. It will thus be seen that by arranging the cylinders in two sets containing
three cylinders each with each cylinder 120 degrees from the next adjacent
cylinder, and connecting their piston rod ends in the manner above described
that the objection of irregularities of rotation, which causes annoying vibrations,
is obviated and an easy smooth-running drill produced.
The crank shaft above described has one end B mounted in a ported plate C,
and its opposite end connected with a rotating bearing portion C+, such end con-
taining an axial opening 63 and provided with a pinion for transmitting power
and motion to a compound train of gears as hereinafter described.
In order to admit fluid pressure to the cylindrical pressure chambers in the rear

page_text: of the pistons that is, between the pistons and cylinder head, the drill casing is
provided with six passages 11, D², D³, D', D³, and 16, one leading to each of the
cylindrical chambers above indicated-the passage D' leading to the cylinder a¹
the passage 1 leading to the cylinder a², the passage 3 leading to the cylinder ³,
the passage D' leading to the cylinder at, the passage D5 leading to the cylinder a³,
and the passage D leading to the cylinder at.
As above indicated, one end of the drill casing is closed by means of a ported
plate C, in which one end of the crank shaft is journalled. This ported plate has
six passages c¹, c², c³, c, and c leading from each of the passages. in the casing
to a point or points near the centre of the plate, where 'they open to the exterior
outer plane surface of the plate. A cap E is secured to the drill casing outside
of the plate and is cupped so as to provide a chamber e into which the pressure
is admitted from the inlet pipe G by means of the throttle valve g, through the
passage g¹. The outer end of the crank shaft is squared and provided with a disc
valve H, which is fitted thereon and adapted to rotate therewith. This disc valve
has a segmental perforation h, and a segmental cup recess h¹, the segmental per-
foration as shown in Fig. 6-allowing the fluid pressure from the valve
chamber e to pass through into several of the ported passages and consequently into
two or more of the cylindrical pressure chambers at one time. The segmental cup-
shaped recess at the same time connects two or more of the ported passages above
indicates with a central annular recess C which is connected with the outer air
by means of the exhaust passages C2 and 0³, so that fluid pressure may be exhausted
to the outer air from such cylinder as are connected with the annular recess by
means of the rotating disc valve.
In Fig. 6 of the drawings the rotating disc valve is so located that fluid
pressure
may flow from the valve chamber through the passage c*, D+ into the cylindrical
pressure chamber at, through passage ², D2, into the cylindrical pressure
chamber a², through passage c6, D6 into the cylindrical pressure chamber a6, and
give an impulse to the pistons of such cylinders. It will be noted from an inspec-
tion of the drawings and the direction in which the disc valve is rotating that the
pistor. of each cylinder obtains its impulse at practically the same period of
operation, viz., the beginning of its forward stroke; and as the valve is arranged
it will be seen that the piston A is just obtaining an impulse while the piston A
is at its best position under full pressure, and the piston A at the limit of its
forward stroke just previous to the closing of its passage.
While these three
.cylinders with their respective pistons are receiving an impulse, the fluid pressure
is being exhausted from the other three. cylinders, and as the index letters a¹, I)¹
and indicate similar cylinder chambers and the passages with which they are
connected, the exhaust of the fluid can be readily followed.
It will be noticed from the above description of the construction of the parts,
that but one valve is used to control the admission and exhaustion of fluid from
all the cylindrical chambers, and that thereby the efficiency and regulation of the
different parts is provided for and practically not timing is necessary-the setting
of the valve for one cylinder automatically adapting it to all the others.
To transmit power and motion as desired from the crank shaft, such shaft is
provided with an independent extension C, above alluded to, which has its end C³,
hearing in the axial recess of the crank shaft. This independent rotating portion
is provided with a large spur gear I, and a smaller spur gear I adapted to be
compounded with the spur pinion on the crank shaft. A second set of what
might be termed "back gears' are provided and arranged in the following
manner:
A longitudinally movable sleeve K is mounted on a fixed rod or shaft k and
provided with three spur gears ₁, and which may be shifted as desired so
as to change the driving of the shank L, which is mounted in the rotating bearing
portion from a slow to a high speed. As shown in Fig. 4 of the drawings, the
pinion on the crank shaft engages with the large pinion of the
gear," and the large gear of the rotating portion engages with the small pinion
back

page_text: "
of the "back gears," so that the high speed of the rotating crank shaft produces
a slow speed of the bearing portion and its shaft. The "back gears are slidingly
mounted on the shaft above alluded to and provided with a yoke M and handle
portion m by which they can be moved longitudinally to the left, thereby causing
the disengagement of the large spur wheel I, and the small spur pinion and the
engagement of the medium sized spur pinion I¹ and the medium sized spur gear
on the back gear ³. In this way a relatively higher speed of the bearing portion
and its shank or tool-holder is produced. By this arrangement of compounding
the gears and movably mounting the back gears, the relative speed between the
crank shaft and the tool-holder may be changed to suit different circumstances
and conditions.
As the crank shaft is constructed, it would be practically impossible to economi-
cally connect a solid connecting rod end therewith; and, in order to provide an
economical and efficient connecting rod end, I construct such end in two parts a¹³
and a pivoted together at a¹³ at their outer portions, their inner shank ends being
screw-threaded-as at a¹--so that a nut a will effectually lock such parts and form
a bearing for the crank pin. The shank end of each connecting rod end is recessed,
as at as shown in Fig. 17-to receive the shouldered end a¹ of the connecting
rod A10 and effectually lock the same in position.
If it be desired at any time to use the drill and attach oarts as a breast or hand
drill, one end of the drill casing may be provided with a rest portion N, secured
thereto in any convenient manner, against which the breast or arm of the operator
may be pressed for the purpose of holding it up to its work: and, in fact the drill
may be provided with any of the usual appliances to suit different circumstances
and conditions necessary for its use in the arts.
I am aware that portable pneumatic drills have been constructed before having
a plurality of cylinders, but such cylinders were all in the same plane: and of
course I am also aware that such portable pneumatic drills has pistons, valves,
and the several ports and passages necessary for working the same, and a tool
shank introduced into the machine. I therefore wish it to be understood that I
do not claim broadly any of these but what I do claim is :-
1. In a pneumatic drill or motor, a disc distributing valve such as H in com-
bination with a ported plate such as C, by which the exhaust is discharged through
said ported plate immediately underneath the valve and above the cylinders, sub-
stantially as herein described.
2. In a pneumatic drill or motor, an independently rotating shaft extension
having a bearing at its inner end in the crank shaft, a pinion, on the crank shaft,
spur pinions on the independently rotating shaft extension, a longitudinally
movable sleeve, spur gears on the movable sleeve for engagement with the spur
pinions of the independently rotating shaft extension, and a side chamber of the
main casing enclosing the movable sleeve and its gears, the whole operating
substantially as herein described.
JOHN D. O'DONNELL, Fel.Chart.Inst.P.A.,
Agent for Applicant, 70/1, Palace Chambers, Westminster, S.W.