by Compressed Air or by Steam.
Year: 1886

page_text: by Compressed Air or by Steam.
I, JAMES SHARON M°COY of 395 Jefferson Avenue in the City of Brooklyn in
the County of Kings and State of New York United States of America, Gentleman
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 relates to pneumatic devices or machines constructed for percussive
and motive purposes wherein a piston or striker carrying a slide valve is arranged
to be reciprocated in its cylinder by a pressure of air forced into or through the
cylinder. The first part of my Invention relates to a pneumatic device or tool in
the nature of a drill or planishing device wherein the piston or striker delivers
percussive blows upon a spindle carried by the frame of the tool or device. The
second part of my Invention relates to a pneumatic motor or engine wherein the
piston is attached to and made to reciprocate a connecting rod similar to an
ordinary reciprocating steam engine.
Reference is to be had to the accompanying drawings forming a part of this
Specification in which similar letters of reference indicate corresponding parts in
all the figures.
Figure 1 is a longitudinal sectional elevation of the pneumatic tool showing a tube
applied for conducting the exhaust to the edge of the cutting point; figures 2 and 3
are reverse side elevations of the cylinder, the outer shell or jacket being removed;
figure 4 is a side view of the striker showing a valve chamber of small diameter
with induction and eduction passages leading into it; figure 5 is a detailed side
elevation showing the tool formed with a shoulder piece to facilitate holding the
tool; figure 6 is a sectional elevation taken on the line x-x of figure 1; figure 7
is a side view of the valve removed; figure S is a longitudinal elevation of the
engine or motor; figures 9 and 10 are reverso views of the cylinder, the outer
casing being removed. Figure 11 is a sectional plan view taken on the line x-x
of figure 8; figure 12 is a transverse sectional elevation taken on the line y-y of
figure 8; and Figures 13 and 14 are reverse views of the opposite ends of the
piston.
A represents the striker, and B the casing or cylinder composed of upper and
lower parts screwed together as shown in figure 1. Surrounding the cylinder is

page_text: the jacket C which, together with grooves and flattened surfaces formed in and
upon the outer surfaces of the cylinder (and hereinafter fully described), forms the
air ducts and passages through which the compressed air enters and exhausts from
the cylinder. The lower part or point C¹ of the casing or cylinder carries the
spindle D that holds the point E, and upon the spindle within the point C' is placed
a coiled spring F the office of which is to return the spindle after each down stroke
of the striker A. The upper part of the cylinder B is formed with the air inlet
passage a figure 3 and exhaust passages b figures 1 and 2, and it is faced off at c
figure 3, and on the opposite side at d d d (shown in figure 2) In the flat
surface c is formed the cylinder induction port and the air inlet passage a opens
into said flat surface c. The exhaust passage opens out from the flat surface d
and in the flat surfaces d¹¹are formed in the cylinder the exhaust ports f ƒ¹.
From the flat surface c the cylinder is grooved as shown at g and on the opposite
side as shown at g'. The groove g leads to the port / (see full lines figure 1 and
dotted lines figures 2 and 3) while the groove g¹ leads to the port h'. From the
flat surfaces dd is formed the grooves i ¹. The groove i leads to the port j
while the groove leads to the port 1 (both ports being shown in full lines figure 1
and in dotted lines in figures 2 and 3). The striker A is made of less diameter
than the internal diameter of the cylinder B so that a space s is formed between
the inner walls of the cylinder aud the striker. The striker is formed with the
transverse valve chamber L' in which is placed the slide-valve L and the striker
has formed in it the passages which reach through to the valve chamber and
these openings or passages coincide or stand in the same plane with the exhaust
ports ff respectively. The striker has also a passage l formed in it which also
communicates with the valve chamber L' and coincides or stands in the same plane
with the inlet port e made in the cylinder B. The striker has also the longitudinal
passages m n formed in it which reach respectively from the valve chamber to the
top and bottom of the striker as shown in dotted lines in figure 1 through which
the compressed air enters and exhausts from both ends of the cylinder for recipro-
cating the striker. The valve L is circumferentially grooved as shown at p p, so
that in its reciprocation caused by air entering the ports j¹ or h h¹ it will open
and close all the air passages made in the striker.
The operation is as follows;-The striker A being in its upper position, air
admitted to the induction port a enters the passage formed by the flat surface c and
passes through the passage g and port h moving the valve L to close passage ¹ and
to connect passages elm thus admitting air above the striker A and at the same
time the valve connects the passages fn to allow exhaust from below the striker
through the space formed by the flat surfaces d d d and passage b. Then the air
through the passage g and port h moves valve L to close the passage k and to
connect passages el n to admit air below the striker and to connect passages m k¹
and to open the exhaust from above the striker and so on alternately causing
the striker to have a rapid reciprocation. The air contained in the valve chamber L¹
at the ends of the valve is exhausted with each movement of the valve through the
ports alternately. The distance between the transverse plane of the port and
that of port h¹ together with the diameter of the valve chamber L' determines the
length of reciprocation of the striker A and these ports are arranged so that the
cut-off by the valve L of the exhaust through the passages m n in the striker is
timed to maintain a cushion of air at both ends of the striker so that there is no
beating of the striker upon the cylinder, or upon the spindle D. The ports j
are arranged in the cylinder a distance from the spindle D (when seated) somewhat
greater than that from the lower end of the striker to the valve chamber L' so that
the air cannot all exhaust from the cylinder but a cushion of air will be always
maintained between the striker and the spindle which renders the blow of the
striker percussive and effective without battering either the spindle or striker.
When, owing to the size of the tool or otherwise, it is desired to economise weight
in the valve L, I use a valve of small diameter and form in the striker at either
side of the valvo chamber L¹ the small grooves q q to direct the compressed air to

page_text: and from the valve chamber through the inlet and exhaust ports in the cylinder,
and by these grooves the same short quick percussive blow may be maintained by
making them of proper length relatively to the distance between the ports j and
h. The striker being of smaller diameter than the cylinder B, thus forming the
space s, the compressed air entering the cylinder completely envelops the striker
so that it is carried in a state of flotation and this enveloping of the striker with
air in the surrounding space & also prevents friction and danger of the striker
binding or sticking in the cylinder; and in most cases, the tool will be constructed
so that the induction port e will be lowermost so the force of air entering the
cylinder will lift the striker A in the space 8 and thus to a large degree overcome
the friction due to the gravity contact of the striker with the cylinder.
When the tool is designed for use under water I shall connect to the exhaust b
the pipe El to lead the exhaust above the surface of the water, the compressed air
being always conducted to the tool through the pipe or hose J and when necessary
in dry work the pipe H may be carried along the tool and its outer end held by a
band o near the working edge or surface of the point E so that the exhaust air will
clear away any dust that might accumulate and interfere with the progress of the
work. The pipe H for the latter purpose might be connected with the inlet pipe J
if desired, as shown in dotted lines in figure 1.
When the tool is designed to be used in mines, I shall construct it with the
shoulder piece or brace K by which the tool may be easily held in horizontal or
vertical position and the inlet port a inay be made through the breast of the
cylinder as shown in figure 5 so that the weight of the inlet tube J will assist in
holding the toel with the port e lowermost so that the entering pressure of air will
have a lifting action upon the striker A as above mentioned. For keeping the
striker A so that the valve chamber thereof will always be in proper alignment
with the inlet and exhaust ports in the casing or cylinder, the striker is formed
with a groove o³ and the casing with a pin o² (figure 11) which enters the groove
and prevents the striker from turning but does not interfere with its longitudinal
movement.
In drilling, cutting, and hammering stone or metal so as to make a smooth
surface, especially in planishing sheet inetal, as well as in other kinds of work to
which the pneumatic tool or device is applicable, a short quick and percussion blow,
as distinguished from a long dead blow, is essential to a rapid and satisfactory
performance of the work. In order that the machine may deliver this character
of blow I construct the striker of such diameter relatively to the diameter of the
cylinder that the space s is formed between the striker and the cylinder, and to
this end also I place the main induction port at the bottom of the cylinder so that
the entering air will lift the striker in the cylinder, thus reducing friction and
obtaining the aid of gravity to prevent excessive wear between the cylinder and
piston at the point opposite the induction port. I also make the distance in the
cylinder between the upper induction port which serves to start the slide valve and
the lower induction port which serves to return the slide valve less than the
distance between the upper induction port in the cylinder which starts the slide
valve at the beginning of the action of the machine and the head of the tool
holding spindle, so that an air cushion will be maintained between the end of the
striker and the head of the spindle, thus causing the striker to deliver percussive
blows through the cushion of air, and I place the induction port in the cylinder
which bears upon the slide valve at the beginning of the stroke with its corre-
sponding eduction port, and the induction port in the cylinder which bears on the
end of the valve at the termination of the stroke with its corresponding eduction
port in such proximity to each other relative to the diameter of the slide valve
chamber or induction and eduction passages leading thereto that very thin lines
of action are attained so that the striker will give a short quick and very rapid
stroke which is so effective in penetrating stone as distinguished from long dead
blows. In using the tool, it will be held with the cutting edge of implement E
pressed in direct contact with the surface wrought upon so that the short quick

page_text: percussive blows of the striker will not be absorbed in motion but will have
full effect in causing the cutting implement to penetrate and rapidly perform
its work.
Referring to figures 8. 11. and 12 of the drawings which show the construction of
the motor or engine it will be observed that the cylinder consisting of the casing B
and shell or jacket C is of the same construction as in sheet 1 and the ports and
passages in said cylinder are precisely the same as in the device or tool above fully
described. The cylinder is mounted in a frame M and held thereto by a strap M¹
with the inlet port e lowermost so that the pressure of the entering air will lift the
piston A and hold it in a state of flotation to avoid friction the piston being made
of less diameter than the cylinder to form the spaces for that purpose The
piston A carries the valve L in a transverse chamber L¹ made through the piston
and the valve moves longitudinally and horizontally to open and close the
ports m n to admit air to the opposite ends of the piston; and the piston is in all
respects of the same construction as the striker in figures 1. 4. and 6 of the
drawings except that it is rigidly connected to the connecting rod N which passes
through the stuffing box N¹ and is arranged to the cross-head O which is connected
by the pitman O' to the crank shaft P so that the reciprocation of the piston in the
cylinder will revolve the said crank shaft. The exhaust port 6 will be made of
about the same size as the inlet port a so that the air will be somewhat confined in
the spaces or the exhaust retarded to cause the air to buoy up the piston and
prevent friction, and this retarding of the exhaust consequent upon the com-
paratively small exhaust port b causes the compressed air above the piston in the
spaces to, in a degree, counteract the upward pressure of the air entering the
port e and thus prevent the piston from being lifted into contact with the cylinder.
Instead of using compressed air, steam may be used for operating the engine.
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. In a pneumatic tool, the striker made of less diameter than the cylinder in
which it moves to form the space 8, substantially as and for the purposes set forth.
2. In a pneumatic tool, the striker formed with a transverse valve chamber in
combination with a tool carrying spindle and a cylinder having ports h h¹ the
valve chamber being formed in the striker a distance from its lower end somewhat
less than the distance from the port h¹ in the cylinder to the tool carrying spindle
whereby a cushion of air will be maintained between the striker and spindle
substantially as described.
3. The combination with the pneumatic tool of the tube H leading from the air
inlet or exhaust to the point of the cutting implement substantially as described.
4. The combination with the pneumatic tool of a pipe connected with the
exhaust port, substantially as and for the purposes described.
5. The pneumatic tool, formed with the brace or shoulder piece K at the end of
the tool, substantially as and for the purposes set forth:
6. The induction port a made at the breast of the tool in combination with the
pipe J so that the latter will tend to hold the tool with the port e lowermost,
substantially as described.
7. A striker, in combination with a tool-holding spindle whose working imple-
ment is in contact with the material being wrought upon.
8. A striker, in combination with a tool holding spindle acted upon by a spring,
the working implement held by the spindle being in contact with the material
wrought upon.
9. A striker, carrying a transverse slide valve in combination with a tool holding
spindle whose working implement is in contact with the material being wrought
upon.
10. A striker and the cylinder which contains it, formed with an appreciable
difference in their diameters thus having an anti friction air cylinder between them

page_text: in combination with a tool holding spindle whose working implement is in contact
with the material being wrought upon.
11. In a steam engine, the piston A connected rigidly to the piston rod N and
formed with steam passages and carrying the slide valve L in combination with
the steam chest having inlet and exhaust ports, the piston rod N being connected
by a rod and crosshead to the crank shaft P substantially as described.
12. The piston A formed with air passages as described, and carrying a
transversely arranged slide valve L and made of smaller diameter than the interior
of the steam chest B to form the space s around the piston in combination with the
cylinder having inlet and exhaust ports formed at or near the centre of the piston
stroke whereby the piston is surrounded and cushioned with compressed air,
substantially as and for the purpose set forth.
13. In an engine, the exhaust 6 (figure 9) made of the same size as induction
port a (figure 8) in combination with said induction port a and the several eduction
ports and channels as described, for the purpose of properly filling space s with air
so as to prevent contact between the piston and cylinder.
14. In an engine, the combination of the eduction ports i i, ff1, b and eduction
channel dd in cylinder B of such size and position in relation to induction
ports a, e, g g' in cylinder B as to detain the exhaust air so as to counteract the
upward pressure of the air on the piston sufficiently to prevent frictional contact of
the piston and cylinder at the opposite side from the induction port a.
15. The piston A made smaller in diameter than the cylinder bore, to form the
surrounding space 8 and provided with slide valve L and formed with ports
controlled by the valve L to admit air to and its exhaust from both ends of the
cylinder in combination with the cylinder having medial exhaust ports and the
medial bottom air inlet port e whereby the pressure of air entering the port e will
lift the piston in space s and prevent friction substantially as described.
16. The striker or piston A having a groove or other ineans o¹ combined with a
pin or other device o in the casing for aligning the ports of the piston with the
ports of the cylinder, substantially as described.