Improvements in Pneumatic Hand Tools
Year: 1895

page_text: Date of Application, 14th May, 1895-Accepted, 22nd June, 1895
COMPLETE SPECIFICATION.
Improvements in Pneumatic Hand Tools
I, JAMI'S WOLSTENOROFT of North-east Corner of Harrison and Willow
Streets, Frankford, Philadelphia, Pennsylvania, United States of America
Manufacturer, do hereby declare the nature of my invention, and in what manne
the same is to be performed, to be particularly described and ascertained in and by
the following statement
This invention relates to pneumatic tools for stone diessing, calking, riveting,
cutting metals, and other purposes, in which the tool is actuated with very rapidly
repented reciprocations
The object of this invention is to provide means whereby the tool is given
motion when in contact with the work, but is caused to cease its motion auto-
matically when the tool is recovered, and the object is moreover to provide means
whereby the speed of reciprocative movement or force of the blows, may be varied
at will under the inmediate control of the workman, and said invention consists in
certam novel subject matter hereinafter described and claimed.
Referring to the accompanying drawing;
Figure 1, is a perspective view illustrating the operation of the tool;
Figure 2, an enlarged longitudinal sectional view of a pneumatic tool, showing
the position of the novel parts when the tool is at rost, and
Figure 3. a partial similar view, showing the position of the novel parts when the
tool is applied to the work, and in motion
The invention may be adapted to pneumatic tools of any well known or other
suitable character. I have illustrated its application herein to a tool of one among
numerous other suitable constructions
A, 1s the cylinder, B, the cylinder head, C, the anvil or tool holder, D, the
tool proper, E, the striker, and F, the valve.
1, is the air induction passage, and 2 and 3 are exhaust openings.
The valve Fs seated at its smaller diameter to slide in bushing 4, and is seated
Ports 5 in the small diameter
at its larger diameter internally to slide on stuken E
of the valve F, admit pressure from the pressure chamber 7 to the actuating
chamber 8 at the back of the striker E, and ports 6 in the small diameter of the
valve F, exhaust said pressure from chamber 8 to the atmos here at 2, alternately.
The valve F is actuated automatically by unbalancing of intermittent pressure in
chamber 8, and constant pressure chainber 7 The port 9 in striker E, 18
controlled by the valve F at its laige diameter, so as to admit pressure from the
chamber 7 to the chamber 10 at the lower end of the striker E, alternately with
the before described admission of pressure to the upper end of the stiker, and the
chamber 10, 1 exhausted by the port 3, controlled by said stuker E.
The anvil C, by means of its flange 14 is suspended between a leather washer 11,
and returning spring 12
The parts thus far described do not form an essential part of my invention.
I extend the head B, and provide therein a suitable throttle valve II, adapted to
open, close, or control the admission of a though the induction passago 1. This
throttle valve 11, is movable in the direction of the length of the tool, or in other
words, in the direction in which the band of the workman is moved to apply the tool
to the work
The throttle valve H, may be variously constructed. It is herein illustrated of
the plug valve type, movable lengthwise, and it has a returning sping 20, to

page_text: produce its outward or closing movement, and a retaining screw 21 to prevent its
being forced w. holly out from its cylindrical seat in the cylinder head B. The
valve II, contains a port 22, opening laterally toward the sent, and in the seat is
located the opening of the induction passage 1, with which the port 22, coincides
when the valve I, is pushed ward. The port 22 of the valve II is connected
with the compressed an supply pipe 1, having a rigid section 23, screwed into the
valve plug H. which serves as a hand-hold, and said pipe has the usual flexible
section 24, which perunt the handling of the tool. A leather washer 25, is placed
under the shoulder 26, of the valve plug H, foi abutment against the extremity
of the head B, when the said valve is moved inward by the hand of the workman
and thereby opened.
Figure 3 llustrates the valve II, in an open position as also in Figme 1, and
Figure 2, illustrates the valve H in a closed position
In operation, the tool is held in the hands of the worhran in the position shown
in Figure 1. When the tool is advanced against the work, the hand that grasps
the valve pipe 23, while performing its share of the advancing force, will involun-
tarily, and without distracting the attention of the workman from his work, cause
the automatic opening of the valve II, and the tool will respond by starting at full
speed When the tool is recovered, the spring 20, will cause the closure of the
throttle valve H. The starting and stopping of the reciprocative motion of the
toul D, is practically instantaneous The sping 20 may be dispensed with, and
the closing as well as the opening motion of the valve H inay be performed by the
hand. By voluntarily moving the valve II to any intermediate position, the
amount of air admitted may be accordingly regulated, and the speed of the tool
determined or varied at will without removing the tool from the work By using
a clamping screw such as 27, the throttle valve may be kopt open and inoperative,
o1 partly open at a desued position of adjustinent.
Having now particularly descubed and ascert uned the name of my said
invention and in what manner the same is to be performed, I declare that what
claim is :-
1 The combination with a pneumatic tool, of a throttle valve, fixed to a supply
pipe, and movable longitudinally to the body of the tool, and controlling the How
of the motive fluid, and means for automatically moving the valve to a retiactive
closed position.
2. In a pneumatic tool, the combination of a cylinder adapted to be grasped by
the one hand of the operator, a throttle valve movable lengthwise of the cylinder,
and having a port opening laterally toward a sent, the latter having an induction
passage with which the port coincides, and a supply pipe extending in the
longitudinal axis of the tool, to which the said valve is fixed and grasped by the
other hand of the operator, substantially as set forth.
3. The combination with a pneumatic tool comprising a tool holding device and
suitable menus for vibrating the tool by the How of compressed fluid, of a fluid
supply pipe extending in the longitudinal axis of the tool, connected thereto and
relatively movable in the duection in which the tool is fed to the work, said pipe
forming a band-bold, and a thinttle valve mechanically connected to said movable
pipe, controlling the flow of the motive fluid.
4. In a pneumatic tool, the combination of a cylinder adapted to be grasped by
the que hand of the operator, a throttle valve comprising a plug attached to the
supply pipe movable lengthwise of the cylinder and adapted to be grasped by the
other band of the operator, and suitable ports controlled by said valve for
admitting or shutting off pressure supply to the operating parts of the tool,
substantially as described.
5. The combination with a pneumatic tool, of a throttle valve comprising a plug
movable longitudinally in the axis of the tool, a supply pipe forming a rigid
continuation of said plug in said axis and serving as a haud-hold, the opening of
said pipe continuing through said plug to a point near its inner extremity, then

page_text: opening laterally toward the cylindrical seat in which the plug slides, and a controlled
passage in said cylindrical seat, substantially as described.
6. The combination with a pneumatic tool, of a throttle valve comprising a plug
movable longitudinally in the axis of the tool, a supply pipe forming a rigid
continuation of said plug in said axis and serving as a band-hold, the opening of
said pipe continuing though said plug to a point near its inner extremity, then
opening laterally toward the cylindrical seat in which the plug slides, and a controlled
passage in said cylindrical seat, and a spring for retracting the said valve to its
Dormal position.
Dated thus 3rd day of May 1895.
DAY, DAVIES & HUNT,
321 High Holborn, London, W.C, Agents for the Applicant.