Improvements in Pneumatic Tools.
Year: 1899

page_text: Date of Application, 14th Mar., 1899-Accepted, 15th Apr.,
1899
COMPLETE SPECIFICATION.
Improvements in Pneumatic Tools.
I, JULIUS KELLER, of 12th and Hamilton, Streets, Philadelphia, Pennsylvania,
United States of America, Mechanical 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:-
My invention consists of an improved construction of pneumatic tool and
valve therefor and also in a novel arrangement of ports or passages whereby the
motive fluid is conducted to and exhausted from the opposite ends of the hammer,
in a most effective manner.
In pneumatic tools as heretofore constructed, where a fluid-actuated valve is
used to control the movement of the hammer or piston, the valve moves either
in an opposite direction or at a right angle to the movement of said hammer or
piston, in which case the blow of the hammer will naturally interfere with the
regular and uniform movement of the valve if the latter does not move in the
same direction with the hammer and if the valve does not work regularly and
uniformly the reciprocation of the hammer will be irregular, which is a very
objectionable feature and very often renders the use of pneumatic hammers
impracticable. This irregular movement of the hammer also causes the valve to
break or become injured and shortens the life of the tool, it being apparent
that if the valve moves in an opposite direction to the hammer that shortly
before the latter strikes the chisel at the left, if the valve moves to the right at
the moment the hammer delivers the blow, said valve will rebound from its
seat, reopen the ports that should be closed and cause the tool to jump or in
other words, the cylinder or tool will move away from the chisel, because the
exhaust from the back end does not occur at the right time.
Now since the hammer strikes from two to three thousand blows per minute,
it can be readily seen, how detrimental this irregular movement must be to the
valve and tiring to the operator. By my invention, however, before the hammer
strikes the chisel to the left, the valve will move in the same direction and when
the blow is delivered, the valve is on the left side, the blow instead of rebounding
the valve from its seat, serving to hold said valve more firmly seated, whereby
all the ports are positively opened at the right time, the movement of the hammer
is regular and unobstructed under all conditions and the jumping or jarring
which has heretofore been an objectionable feature in pneumatic hammers, is
practically overcome.
To the above ends, my invention consists of the novel construction and arrange-
ment of ports and passages of a pneumatic tool, as will be hereinafter more fully-
set forth and particularly pointed out in the claims;
Referring to the accompanying drawing:
Figures and 2 represent longitudinal sectional views of a pneumatic tool
embodying my invention, the sections being taken on line C, D, Figure 5, show-
ing the hammer in its different extreme positions.
Figure 3 represents a longitudinal sectional view on line A, B, Figure 5..
Figure 4 represents a section on line - Figure 1.
Figure represents an end view of the tool with the handle portion removed,

page_text: •
showing in dotted lines the general arrangement of ports and passages in the
cylinder thereof.
Figure 6 represents a perspective view of the valve employed.
Similar letters of reference indicate corresponding parts in the several figures.
I designates the handle of a pneumatic tool, in which is located the throttle
valve 3, which latter controls the flow of the motive fluid from the various
ports and passages in the cylinder, said handle having the inlet port a therein
to which is connected a suitable supply pipe, the fluid under pressure flowing
into the chamber 6 and then entering the ports e in the throttle bushing C; said
throttle valve being held by the spring 5 against the throttle lever 4.
7 designates a regulating screw engaging the handle 1 which can be readily
manipulated to regulate the movement of the throttle valve, the regulating device
being held in position by means of the latch pin S provided with the pointed
end 8. When the throttle lever 4, is pressed downwardly the throttle valve 3
will open the port d whereupon the 'motive fluid will pass through the passage e
and enter the inner chamber of the valve 9 through the port f, the construction
of said valve being. readily understood from Figure 6. When the valve 9 and
the hammer 13 are moved-to the right or towards the handle 1 as seen in Figure 1,
the ports in the valve chamber are, open and permit the motive fluid to pass
into the cylinder casing 12, through the port and drive the hammer to the
left or forwardly, until it strikes the tool or chisel 14* contained within the chisel
bushing 14. Just before the hammer reaches its extreme forward position the
neck or groove y therein will permit communication between the ports and g
whereupon live or compressed air passes through the port the passage o and
the port p, passing thence through the port y and passager to the ports s¹ and s,
at which point the motive fluid enters the valve chamber acting on the larger
concave pressure area 9* of the valve 9, thereby driving the same towards its
left or forward position, as seen in Figures 2 and 3, the ports g and h being now
closed for the inlet and open to the exhaust port m by means of the groove y³
for said valve, wherefrom it will be seen that the motive fluid from the back
end of the hammer can now exhaust through the porta h and g, groove y' and
exhaust port m into the atmosphere through the port m.
If we assume the parts to be in the position seen in Figure 2 and the valve 9
seated or moved to the left, it will be seen that the port t is open for, the admission
of the motive fluid, which latter will flow through the passages t, and port i
to the front end of the hammer and drive the latter to the right or backwardly
until the port w is open. The air which acted on the large pressure area of
the valve to hold the same down is now relieved as the exhaust port is open at the
same time when the port u is open. The air from the large pressure area of
the valve exhausts through the ports, passage r, portu, port, passage and
the port into the atmosphere. The constant pressure which is always acting
on the smaller pressure area of the valve now drives the latter to the right or
backwardly into the position seen in Figure 1, thereby closing the inlet port t
and opening the exhaust port 7. The air from the front end of the hammer will
now exhaust partly through the port and when the same is closed by the
hammer, through the port i, passage and port 7 the latter being connected with
the exhaust port m by means of the neck or groove y* in the valve 9, the port g
being now open, again to admit fluid pressure into the cylinder.
By making the valve 9 solid and providing. the same with the reduced portion y
and the concavity 9 which permits fluid pressure to be equally-exerted on all
parts thereof, and also with the projecting portion 9, which controls the port t,
a simple, cheap and durable valve is produced. The valve box 10 in which the
valve 9 is located, has the cap. 11 pinned thereto, the whole being pinned to
the tool cylinder 12 to which latter the handle 1 is secured, said cap having the
ratchet teeth 11*, which are engaged by the spring-pressed pawl or plunger 10,
which has a member 2 for enabling the same to be readily manipulated.
I desire to lay ospecial emphasis upon the advantages of my invention, since,

page_text: before the hammer strikes the chisel at the left, the valve will move in the
same direction, and when the blow is delivered the valve is on the left-hand side,
the blow instead of rebounding the valve from its seat, holding said valve more
firmly seated, all the ports being open at the right time and the regular and
uniform movement of the valve and consequently of the hammer, being un-
obstructed, whereby jumping, jarring and other objectionable features of pneu-
matic tools, now in use, are practically overcome.
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. In a pneumatic tool, a valve for controlling the movements of the hammer,
said valve being located exteriorly to said hammer and adapted to move in the
same direction as the latter, the blow of said hammer holding the valve more
firmly to its seat.
2. In a pneumatic tool, a solid hammer and a valve for controlling the move-
ments thereof, said valve consisting of a cylindrical shell located out of the path
of said hammer, and provided with opposing pressure arms against which the
motive fluid acts to shift the valve in opposite directions.
3. In a pneumatic tool, the combination of a hammer, ports and passages for
conducting the motive fluid to and from said hammer and a valve located out
of the path of said hammer, said valve moving in the same direction as said
hammer when the latter is in the act of striking a blow, and means for enabling
said blow to seat said valve more firmly.
4. In a pneumatic tool, a valve consisting of a hollow cylindrical shell located
out of the path of the hammer and provided with opposing surfaces of different
area, against the smaller of which the motive fluid constantly acts to press the
valve in one direction and to the larger of which the motive fluid is intermittently
admitted to move the valve in the opposite direction.
5. In a pneumatic tool, the combination of a cylinder containing a hammer
and a valve located out of the path of said hammer and provided with opposing
pressure areas against which the motive fluid acts to shift the valve in the
opposite direction.
6. In a pneumatic tool, a valve for controlling the movement of a hammer,
the same consisting of a cylindrical shell having its interior constantly open to
fluid pressure and out of the path of said hammer, said valve having opposing
pressure areas to which the motive fluid is admitted to shift the valve in the
opposite direction.
7. In a pneumatic tool, the combination with the cylinder and its hammer
of a valve located exteriorly to said hammer and out of the path thereof, said
valve consisting of a cylindrical shell having its interior subject to. fluid pressure
and provided with differential pressure areas against the smaller of which the
motive fluid constantly acts to press the valve in one direction, and passages
controlled by the piston for intermittently admitting the motive fluid to the
larger pressure area to move the valve in the opposite direction.
8. In a pneumatic tool, the combination of a hammer, and a valve located
exteriorly to and out of the path of said hammer, said valve being provided with
different pressure areas against the smaller of which the motive fluid constantly
acts to press the valve in one direction and passages controlled by the piston and
opened by the latter at its forward stroke to admit the motive fluid to the larger
area of said valve.
9. In a pneumatic hammer for a pneumatic tool, the herein described valve,
consisting of a cylindrical shell having a reduced portion or neck y' and 'an
enlarged pressure area 9, the latter being provided with a projecting flange con-
trolling a live steam port, the interior of said shell being constantly subjected to
fluid pressure.
10. The herein described valve consisting of a cylindrical shell having a reduced

page_text: neck, the differential pressure areas formed by the enlargement 9 and the
projecting portion 9**.
11. In a pneumatic tool, a hammer, a valve located at the rear end out of the
path thereof, said valve consisting of a cylindrical shell provided with differential
pressure areas against the smaller of which the motive fluid constantly acts to
press the valve in one direction, a passage controlled by the hammer and opened
by the latter to admit motive fluid to a larger area of the valve to move the
latter forwardly, said valve being moved backwardly by the constantly acting
pressure against its smaller area.
12. In a pneumatic tool, a cylinder containing a hammer, a valve for controlling
the passage of the motive fluid within said tool, said valve being located above
the path of said hammer and having differential pressure areas, ports controlled
by said valve for conducting motive fluid to the back end of the hammer, ports
controlled by said valves for admitting steam to the forward end of said hammer, a
port leading from the valve chamber and thrown into communication by a neck in
Said hammer, with a discharge passage leading to the larger area of said valve, where-
by the latter is seated, said valve moving in the same direction as said hammer and
being held firmly against its seat at the period when said hammer reaches the
forward end of its stroke, in combination with means for actuating said hammer
and valve in opposite directions.
13. The combination with a pneumatic tool of a hammer having a reduced
portion, a valve having differential pressure area and the reduced portion
or neck the interior of said. valve, being also open to fluid pressure, ports and
passages controlled by said valve in each of its extreme positions for permitting
the motive fluid to act upon each end of said hammer, a port n for admitting motive
fluid to the passage, port and port 1, when the two latter are thrown in
communication by the neck y of said hammer, a passage and port s for per-
mitting live steam to act upon the larger area of the valve, whereby the latter
is moved forwardly simultaneously with the forward movement of the hammer,
a port adapted to be uncovered by said hammer when the latter moves back-
wardly, a passage and port. leading from said port, said port. communicating
with said neck of said valve, whereby the latter is moved rearwardly simul-
taneously with the rearward movement of said hammer and suitable exhaust
passages for permitting the exhaust of the motive fluid during the rearward
movement of said hammer.
14. A solid valve having a passage therethrough, a reduced portion
differential pressure areas, a concavity in the larger of said pressure areas, and
an extension 9 for controlling a steam inlet port.
15. In a pneumatic tool, a valve box having a valve 9 therein, the interior
of said valve being always open to fluid pressure, a handle engaging the cylinder
of said tool and having a port discharging substantially centrally from raid
handle into the interior of said valve and ports and passages leading to and
from said cylinder controlled by said valve.
16. In a pneumatic tool, a solid valve having a reduced portion and a solid
hammer also having a reduced portion, the interior of said valve being always
open to fluid pressure..
17. A solid valve consisting of a shell having a reduced neck and differential
pressure areas, the interior of said valve being always subject to fluid pressure.
18. In a pneumatic tool, a handle, a valve-box having a cap secured thereto
and a cylinder and a spring-pressed plunger, seated in said handle and adapted to
engage teeth on said cap.
da 1900
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.