Improvements in Pneumatic Percussive Hand Tools.
Year: 1895

page_text: Date of Application, 12th Nov. 1895-Accepted, 25th Apr., 1846
COMPLETE SPECIFICATION.
Improvements in Pneumatic Percussive Hand Tools.
JULIUS KELLER, of No. 821 Cherry Street, 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 a novel construction of pneumatic tool, which is adapted
for all uses in which a hammer or mallet, and chisel are ordinarily employed.
It further consists of a novel construction of throttle valve and its adjuncts.
In the accompanying drawings
Figure 1 represents an exterior view of a pneumatic tool-embodying my
invention.
Figure 2 represents a longitudinal sectional view of the same, showing the relation
of the hammer to the inlet and exhaust ports, and the construction of the throttle
valve.
Figure 3 represents another longitudinal sectional view, showing more clearly
certain of the inlet and exhaust ports, the hammer being in the same position, and
the right band end of the tool being broken away.
Figure 4 represents a view similar to Figure 2, the hammer being shown in
another position relative to the several ports.
Figure 5 represents a transverse section on line x, x Figure 3, and
Figure 6 represents a longitudinal sectional view, showing a modified form of
hammer.
Similar letters of reference indiente corresponding parts in the several figures.
I designates a cylinder or casing, and E the inlet opening for the motive fluid,
which is preferably compressed air, from which point E extends the inlet port 3,
which communicates at 4, with the interior of the casing, within which reciprocates
the hammer 6, which is of reduced diameter at the parts 7, 8 and 9, thus forming
annular grooves, said hammer having enlarged portions or pistons 10, 11, 12, and 13,
which are in contact with the interior walls of the cylinder, it being understood
that the annular groove 8 of the haminer serves in conjunction with the port 4' to
control the admission of the motive fluid to each end of the cylinder, while the
annular grooves 7 and 9 in conjunction with suitable outlet ports allow the dead air
to be exhausted alternately from the ends of the cylinder, as will be explained.
14 designates a port in the cylinder 1,-which has one end 15 communicating with
the left hand extremity of the interior of the cylinder; while its other end 16 also
communicates therewith a little to one side of the centre thereof.
In like manner the port 17 has its end 18 open into the right hand end of the
interior of the cylinder, while its other end 19 opens thereinto at one side of the
centre.
20 designates an exhaust passage which cominunicates with the interior of the
cylinder by the ports 21 and 22, which are located one on each side of the centre,
as will be evident from Figures 2 and 4, said exhaust passage 20 communicating
with the exterior air at the point 23.
The construction of the device for throttling the inlet passage' E will now be
described, reference being had' to Figures 1 and 2.
C designates a plug which is screwed or otherwise connected to the end of the
cylinder, said plug having attached thereto the extension D, within which is 'the

page_text: inlet passage E, which communicates by means of the passage 3 with the interior
of the tool.
G designates a transversely-extending passage in said plug C, within which is
located the throttle valve H, the same consisting of the plug portions K and J,
which are connected by means of the neck N, the portion L of said valve above
the cylindrical plug portion K being preferably flattened in the present instance,
and extending through a slot in the throttle collar Q, whereby the latter is
prevented from rotation.
M designates the inclined or bevelled top face of said valve H, which is held
normally in the position seen in Figure 2, by means of the spring P, one end of the
latter abutting against the bottom of said throttle valve, while the other end is in
contact with the inuer portion of said collar Q.
-
R designates a hole in the end of said collar, through which the extension D
projects, said collar Q having a bearing upon the latter and a suitable portion of
said plug C, and having at its extremity the counter-bore T of increased diameter,
thereby providing a shoulder T', which is adapted to abut against the end T of
the cylinder B thereof, and thus forms a stop as will be readily understood from
Figure 2.
U designates a stud or pin which is movable in a suitable cavity in the plug C,
said plug resting upon a suitable spring, whereby it is forced into a seat in the
cylinder B, when the parts are in the position secu in Figure 1, the plug and
cylinder being thus locked with respect to each other, a suitable hole being located
in the cylinder B, over said stud for pushing in the latter when it is desired to
remove the plug C for any purpose.
The left hand end of the cylinder 1 is screw-threaded, and provided with a
shoulder 29, against which the plate 30 is firmly held by means of the abutting
portion of the nose piece 31, which is sorewed against it. The said plate 30 has a
central opening therein, through which extends the shank 32 of the head 33, which
latter is of larger diameter, and is held in position and is guided by means of said
nose piece, the movement of said head' being limited by the shoulder 34, which is
formed at the junction of the bores 35 and 36, the latter serving to guide the
bead 33, and the former serving to hold the shank of the tool 37, shown in
Figure 2. The construction seen in Figure 6 is substantially the same as in
Figures 1 to 5 inclusive, except that the hammer 6x* within the cylinder 1, has
only the central annular groove 8x, the end grooves 7 and 9 shown in the other
hammers being dispensed with, the arrangement and operation of the inlet ports,
throttle valve, collar and the like being the same as in the other previously.
described constructions, the cylinder exhausting through the ports 3* and 4* as is
evident.
The operation is as follows: Referring first to Figures 2 and 3 in which the
hammer 6 is at nearly its extreme left hand position, the compressed air or other
motive Huid entering the inlet E, passes through the passage 3 and port 4 into the
interior of the cylinder, and since the hammer, is provided with the central annular
groove 8, the fluid passes into the port 16, and out of the port 15, and the hammer
will thus bo moved from left to right, the cylinder exhausting through the
ports 18, 19 and 22, into the passage 20, and thence freely into the air, through
the outlet port 23. In like manner the hammer 6 will be moved from right to left,
as will be understood from Figure 4, where said hammer is shown at its extreme
right hand position, the motive fluid entering the port 4 as before, and passing
thence through the ports 19, and 18, to the right hand end of the cylinder, moving
the hammer to the left, the exhaust taking place through the ports 15, 16, 21-and
paseage 20), as before.
The tool seen in Figure 6 operates as has already been described, the location
and operation of the inlet and exhaust passages and ports relative to the hammer
being the same.
It will be noted that by making the hammer 8 portless and valveless, I obtain the
greatest strength and durability possible, and that by reducing the number of parts

page_text: to a minimum all liability of disarrangement or accident to the same is removed.
Although I have shown the nose piece made separable from the casing, and also
the opposite end portion or plug which contains the compressed air inlet and
throttle valve, it is obvious that variations may be made in the manner of
assembling the above parts.
The operation of the throttle valve is as follows: Referring first to Figure 2, it.
will be seen that when the parts are in the position seen therein, the passage E is
throttled.
When it is desired to start the tool, the operator presses the throttle collar Q
towards the hammer in the direction of the arrow, and by the contact of the
inclined faces M and D, the valve H is moved in wardly, the neck N being thus.
opposite the passage E, whereby the motive fluid is permitted to freely pass to the
interior of the tool. When the operator removes the pressure from the collar Q,
the tension of the spring P will cause the valve H to move outwardly, and the
contact of the said faces M and S will move the collar Q outwardly, or away from:
the hammer, the parts now assuming the position seen in Figure 2 again, the valve
being prevented from moving out of the contact with the inclined faces, as will be
evident, while the contact of the parts T' and T2 will properly limit the movement
of the collar Q
The parts are assembled in position by first inserting the valve H in place, and
then pressing the same inwardly so that the collar Q can be pushed over the same,
the spring afterwards causing said valve to assume the position seen in Figure 1,
the flattened portion L of the valve extending through the slot in the collar Q, and
preventing the latter and the valve from rotating.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1st. In a pueumatic tool, a cylinder, a portless, valveless hammer therein, the
latter being provided with a groove intermediate its ends, an inlet passage in
communication with said groove, passages alternately in communication with the
latter and the ends of the cylinder, and adapted to serve alternately as inlet and
exhaust conduits for the motive fluid, and means for conducting the exhaust to the
exterior of the cylinder, substantially as described.
2nd. In a pneumatic tool, a cylinder, a portless, valveless hammer therein, the
latter being provided with a centrally located groove, an inlet passage always in
communication with said central groove, passages alternately in communication
with the latter and the ends of the cylindor, and adapted to serve alternately as
inlet and exhaust passages for the motive fluid, and means for conducting the
exhaust to the exterior of the cylinder, substantially as described.
3rd. In a pneumatic tool, a cylinder, a hammer therein having the annular
grooves 7, 8 and 9, and the enlarged portions 10, 11, 12, and 13, the passage 3, and
the inlet port + always in communication with said central groove 8, passages in
communication with the latter, and the ends of said cylinder adapted to serve
alternately as inlet and exhaust conduits, exhaust ports adapted to register with
said grooves 7 and 9, and an exhaust passage common to both of said exhaust ports,
substantially as described.
4th. In a pneumatic tool, a cylinder, a hammer therein having a centrally located
annular groove, always in communication with the inlet passage for the motive
fluid, passages having each an end in communication with the ends of the cylinder,
the other ends of said passages being alternately in communication with said
groove, and serving alternately as inlet and exhaust conduits for the motive fluid,
means for conducting said exhaust to the exterior of the cylinder, and means for
throttling said inlet passages, substantially as described.
5th. In a pneumatic tool, a cylinder, a hammer therein having a central annular
groove, passages in said cylinder which communicate with said groove and the ends
of said cylinder, and serve alternately as inlet and exhaust conduits for the

page_text: motive fluid, an inlet passage for the motive fluid also communicating with said
groove, and a suitable exhaust passage leading to the exterior of the cylinder,
Bubstantially as described.
6th. In a pneumatic tool, a cylinder, a non-rotating hammer therein having the
annular grooves 7, 8, and 9, the inlet port 4, suitable passages leading therefrom
to each end of the cylinder, which serve alternately as inlet and exhaust conduits
for the motive fluid, exhaust ports 21 and 22 and a passage leading therefrom to
*the exterior of the cylinder, substantially as described.
7th. A pneumatic tool having a throttle valve therein a throttle collar disconnected
from said valve, and adapted to operate the latter, in combination with means for
-automatically moving said valve and collar in unison, substantially as described.
8th. In a pneumatic tool, a plug, a passage therein, an extension on said plug,
a throttle valve for said passage, a collar mounted on said extension, and
disconnected from said valve, a spring intermediate said valve and plug, and
means for moving said collar and plug in unison, substantially as described..
9th. In a pneumatic tool, a plug, a passage therein, for the admission of the
motive fluid, a throttle valve located in said passage, a spring for actuating said
valve, a throttle collar, a bevelled portion commou to said valve and collar, and
means for limiting the movement of the latter, substantially as described.
10th. In a pneumatic tool, a plug, a hollow extension thereon, an element
movable on said extension, means for limiting the movement of said element, a
throttle valve, and a spring or other device for actuating the latter, substantially
:89 described.
11th. In a pneumatic tool, a throttle collar, and a throttle valve therefor,
disconnected from said collar, the latter and said valve having bevelled edges in
juxtaposition, in combination with means for holding said valve normally in the
desired position, substantially as described.
12th. In a pneumatic tool; a throttle valve, a throttle collar disconnected
therefrom, and adapted to actuate the same, in combination with a spring bearing
on a suitable portion of said valve, substantially as described.
13th. In a pneumatic tool, a throttle valve, a throttle collar therefor, cach having
a bevelled edge in juxtaposition, means for limiting the movement of said throttle
collar, in combination with means for holding said collar in position, substantially
as described.
14th. In a pneumatic tool, a throttle collar and a valve, each having a bevelled
edge in juxtaposition with each other, and means for actuating said valve,
-substantially as described.
Dated this 19th day of November 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicaut.