Improvements in Percussive Apparatus, chiefly designed for Reducing the Burr on Electrically Welded Metal Articles.
Year: 1890

page_text: Date of Application, 16th Dec., 1890-Accepted, 28th Feb., 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by WILLIAM MAXWELL WOOD, of Boston,
Massachusetts, United States of America.]
Improvements in Percussive Apparatus, chiefly designed for Reducing
the Burr on Electrically Welded Metal Articles.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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:-
This invention relates to pneumatic tools of the class in which hammers, dies,
Swedges, cutters or other instruments are operated, by rapidly repeated movements
of a piston or plunger actuated by the pressure of air, gas, steam or other fluid
under pressure.
The invention is designed particularly for use in instruments employed for
reducing the burr or expansion at the weld formed between two pieces of metal by
the ordinary process of electric welding in which end pressure is employed, though
the novel features of construction and combinations of devices hereinafter described
are many of them useful in pneumatic tools generally.
The invention consists in the novel combination, as hereinafter described, of two
reciprocating pistons which may act as the valve movement for controlling the fluid
pressure upon the pistons or plungers carrying the tools, or may be used for
actuating a tool directly.
The invention consists also in a novel construction where a large number of tool
operating plungers may be employed and the instrument may be still conveniently
applied to and removed from the work.
The invention consists further in the means for automatically throwing the
instrument into and out of operation in the act of applying it to and removing it
from the work, and also in other features hereinafter more particularly specified.
In the accompanying drawings:-
Fig. 1, shows in vertical section, and partial side elevation, an apparatus
embodying my invention wherein the pressure of air, gas, steam, or other fluid is
employed to operate the plungers which actuate the tool.
Fig. 2, is an end view of the parts at the joint enlarged.
Fig. 3, is a horizontal section on the line X, X, Fig. 2, through the joint and the
valve movement contained therein.
Figs. 4 and 5, illustrate the two sides of the joint respectively, detached from
one another.
Fig. 6, is a side elevation of the plug or pin which connects the two sides or arms
of the apparatus.
Fig. 7, illustrates a modification in the construction of the apparatus at the joint
and handle portion of the same.
Fig. 8, shows in vertical central section a modified construction of tool wherein
the automatic valve movement is located at a different point and the frame carrying
the tool operating plungers is not jointed.
Fig. 9, is a vertical longitudinal section and partial side elevation of another
form of the invention, and shows the application of the automatic valve movement
to the operation of a hammer or die directly.
Referring to Fig. 1, A, B, indicate respectively the two sides or arms which form
the support for the several hammers, dies, or other tools employed, and the parts
actuating the same. The two arms A, B, are hinged together or otherwise movable
with relation to one another so that they may be swung apart so as to permit the

page_text: instrument to be applied over the work, here illustrated at W, as a round bar
or rod.
The two arms or supports A, B, may be hinged or jointed in any suitable
manner, but preferably by means of an ordinary knuckle joint, parts of which are
indicated in Figs. 4, 5 and 6, Fig. 6, showing the plug or pin for the joint.
A2, B2, are handles by which the two arms A, B, may be opened and closed.
The two arms or supports A, B, carry the four tool operating plungers H, H, H,
here shown as pistons working in cylinders in the arms A, B, and adapted to be
reciprocated by fluid pressure applied alternately at opposite sides of the pistons
through chambers or passages i, 1. The plungers H, are arranged as shown to
operate on converging lines so that they may act all together upon the work W.
The tools operated by said plungers are here shown as hammers H2, but could be
other tools. The passages i, i, all connect with a port to be presently described,
through which the air, gas, steam or other fluid under pressure is delivered through
the passages and to the cylinders at one side of the pistons, while the passages 1,
connect with a similar port for delivering air or other gas or fluid under pressure to
the opposite side of the piston. The pressure at ports connecting with i, 1, is
controlled by a valve movement, as will be presently described. Instead of a valve
controlling the admission of air, gas, steam or other fluid under pressure any other
means might be used for producing pressure at opposite sides of the pistons H,
alternately. The ports referred to serve also as exhaust ports in the preferable
construction of the apparatus. The plungers may be cushioned on their back stroke
by means of projections on the cylinder's head adapted to fit into air cups or cavities
in the piston heads or plungers. The fluid employed for operating the plungers
being supplied through a flexible conduit, the instrument may be held in the hand
and turned around the work so as to bring the tools to bear on all parts of it.
O, O, are sliding gauges fixed to the arms carrying the tools and adapted to
engage with the work as indicated so as to adjust the hammers for different sizes of
work and cause them to be normally equi-distant from the centre.
The valve movement which controls the passage of the fluid to the plungers may
be mounted in the pin or plug V, connecting the two parts of the hinge. I prefer
to employ for this valve movement, a combination of valves invented by me and
arranged as follows:-
D, D, is a double acting piston working in a suitable chamber as shown and
kept in operation by air or fluid pressure admitted alternately at opposite ends of
the cylinder through the ports a, a'. The piston heads D, are connected by a
rod D, thus leaving a pressure space which is put in communication by the
reciprocation of the piston alternately with the ports which form openings between
the pressure space and the pressure spaces of another double acting piston C, C.
Passages K, L, extend transversely through the plug V, carrying the plungers, and
in line as shown so as to make ports or passages indicated at K, L, Fig. 3,
connecting the spaces in which the pistons D, C, work. These passages K, extend
completely through the plug, as shown, and at the surface thereof are enlarged as
indicated by the dotted lines in Fig. 6, for the purpose to be presently described.
Air, gas, or other fluid, under pressure, is delivered to the space between the piston
heads D, through the port or opening P, as will be presently described. Suitable
stops are provided for the double piston D, at the end of the cylinder in which it
works, and by suitable construction the piston may be cushioned at the end of a
stroke by confining the air or gas under pressure in cavities or cups upon the piston
heads which slip over projections on the cylinder heads at the end of a stroke.
C, C, is a second double acting piston which is kept in operation by air or gas
pressure admitted alternately through ports K, L, Fig. 3, to spaces at the inside
of the piston heads. The piston heads are connected by a rod as shown working
through a diaphragm, and the connecting rod may have a packing at the point
where it passes through the diaphragm, if desired, although this is not absolutely
necessary, since a slight amount of leakage from one side to the other will not
prevent the operation of the apparatus. Piston heads C, C, alternately cover and

page_text: uncover the ports a, a¹, for admission of the air or gas under pressure to the cylinder
in which the piston D, works. This air or gas pressure is conveniently and preferably
taken from the part of the cylinder for piston C, C, wherein the pressure exists for
operating the latter. Piston C, C, may be cushioned at the end of each stroke by
allowing the piston heads to confine a small volume of air between the head and the
diaphragm, in obvious manner, and the cushioning action may be assisted by means
of springs, should it be deemed desirable. These springs may also aid in reversing
the movement of the piston. The outer ends of the cylinders for the double piston C,
are left open to the outer air or to an exhaust chamber so that ports a, a', when
uncovered by a movement of their piston C, towards the central diaphragm may
form exhaust ports for the cylinder in which the piston D, works.
To make the operation of the two pistons D, D, C, C, in the manner to be
presently described, control the action of the plungers H, H, it is simply necessary
to put the passages i, 1, in permanent connection with the spaces at the inner sides
of the heads C, C. This connection is made by means of the passages K, L, merging
in the ports located in the walls between the two pistons as shown in Fig. 3, and the
ports K, K, L, L, Figs. 4 and 5, in the two parts of the hinge. Port K', com-
municates with the passage 1, in one arm or part of the apparatus, and port K², in
the other part of the hinge communicates with the passage 1, in the other side or
arm. The transverse passage K, in the plug is enlarged at 6, towards the end of
the plug so as to be brought into registry with port K³, and is at the other side
of the plug enlarged in the opposite direction as indicated at 5, so as to register
with the port K². The transverse passage L, is enlarged longitudinally of the plug,
as indicated at 8, so as to form communication with the port L³, leading to the
passages i, in one side or arm as A, and is enlarged as indicated at 7, towards the
middle of the plug so as to register with the port L2, in part B, connecting with
passages i, in such part or arm B.
The operation of the automatic valve movement described in connection with the
several plungers, is as follows:-
In the position of the pistons shown the air passes by port K, and port a, to one
side of piston .D, the space at the opposite side of piston D, being open through the
port a', to the exhaust. The piston D, is thereupon moved with the effect of shutting
off the air pressure at port K, from piston C, and opening the port L, for communi-
cation with the source of air pressure. At the same time the movement of the
piston D, is sufficient to open communication, by port K, with the space at the left
hand end of the cylinder for D, so that the air or gas may exhaust from the pressure
space at the left end of the double piston C, as soon as the said piston C, moves
slightly to the right and opens the port a, at the rear side of the piston head C.
Piston C, now moves to the right until finally it opens communication by way of
the port a', between the space at the inside of the right hand end of piston D, to
produce reverse movement, the exhaust at the opposite end of piston D, taking
place_now through port a. The piston D, by its reverse movement opens the
port K, for admission of air or gas under pressure to cause movement of piston C,
to the left, the exhaust for such piston C, now taking place through port L, which
has been uncovered by the movement of D, to the left so that the exhaust may
pass through the cylinder D, and out by port a. The reversal of movement of
the large piston C, by each stroke may be assisted by a spring as well as by the
fact that the piston D, after covering port K or L, and so as to shut off the air
pressure from C, and open the port K, or L, as an exhaust, will, on continuation of
its movement, produce rarefaction of the air or gas which may be confined in the
position of the piston C, shown, thereby causing an inequality of the pressures
tending to move the piston C, after communication is established by way of port L,
to the space at the inside of the right hand piston head C.
It will be obvious that as the ports K, L, communicate with the spaces between
the piston heads C, and the diaphragm between them, where pressure and exhaust
take place alternately, that there will be in the passages i, 1, and in the spaces at
the opposite sides of the plungers H, H, H, a condition of alternate pressure and

page_text: exhaust or lowering of pressure which will cause said plungers to reciprocate with
the piston C. Thus when there is pressure in the space between one of the piston
heads C, and the intermediate diaphragm tending to move said piston in one
direction, as for instance in the space communicating by port K, with the passages 1,
there will be at the same time exhaust passages opened for the escape of the steam
or other fluid under pressure from the space between the inner side of the other
piston head C, and the intermediate diaphragm, so that the pressure in the passages i,
communicating with port Z, may be relieved. Under this condition the pistons H,
will move back away from the work through the pressure communicated through K,
and passages, the exhaust taking place through, and L, a. When, however,
the valve mechanism moves in the opposite direction through the pressure com-
municated to the space between the head C, and the intermediate diaphragm, with
which space port L, communicates, there will be, as before described, an exhaust
for the air, gas, steam or other fluid under pressure in the space with which the
port K, communicates so that under this condition of affairs pressure will now be
communicated through K, and passages i, to the rear of the plungers H, while an
exhaust will exist through the passages I, the port L, and the port a.
It will be observed that the ports K, L, are pressure and exhaust ports for the
double acting piston C, and are controlled by the action of the double acting
piston D, D, so as to produce reciprocation of the piston C, while in the same
manner the ports a, a', are alternately inlet and exhaust ports for piston D, and are
controlled by the movements of C. Each piston operates, therefore, as a valve
for controlling the inlet and exhaust of the other by means of two sets of
ports a, a, K, L, and each piston moves in its own cylinder and is not, as in some
previous constructions, carried by the other.
It will be seen that the organization is extremely simple and in practice I find
that a perfectly automatic motion of great rapidity and absolute certainty is
obtained whether such piston, or the valve movement of one of said pistons, be
applied to controlling admission of air or gas under pressure to other pistons or
plungers, or whether the movement of one of said pistons be employed to actuate
directly or indirectly any suitable tool.
By operating the tool by means of plungers H, independent of the valve move-
ment, I obtain the advantage that the stroke of the plunger carrying the tool may
be variable and is entirely independent of the movement of the automatic piston
valves where there is practically a fixed length or stroke.
It will be observed that by simply connecting the cylinders for the
plungers H, H, with spaces or chambers of the automatic valve movement where
there is alternately a pressure and exhaust in the operation of such valve movement,
I obtain the maximum of simplicity and in the operation of a separate set of
plungers carrying the tools by the controlling action of one of the pistons of the
automatic valve movement.
The air or gas under pressure is supplied to port Ps, through passage P, in one
part or side B, of the hinge or joint. The plug V, is fastened by means of
screws S, in the other side A, so that the two ports or openings P, P³, will move
with relation to one another when the arms A, B, are swung apart or together.
In the position shown where the tool is closed down upon the work the ports P, P³,
register with one another and the air, steam or other gas or fluid under pressure
may pass to the tool for the purpose of operating the plungers and valve
mechanism. When the tool is opened to remove it from the work the ports P, P³,
move with relation to one another into position indicated by the dotted lines Fig. 2,
and the air or other fluid is cut off.
The ports P, P³, moved with relation to one another by the closing or opening
of the arms thus constitute an automatic cut-off controlling the flow of the agent
which supplies the power for operating the tool.
Any other arrangement of valve or cut-off device properly combined with the
two arms so as to be closed and opened by the movement of such arms would be
within this part of the invention. It will be obvious that if the plungers were made

page_text: like the cores of electro-magnets and operated by electric coils the flow of electric
current to the coils might be controlled in the same way by an electric switch or
cut off actuated by movement of the arms carrying the plungers and coils.
The air, gas, steam or other fluid under pressure is supplied to the passage P,
through a flexible tube P2, or by other means.
In Fig. 7, I have illustrated a modification in the arrangement of the handles
with relation to the apparatus. Here the handles connect with the device at the
joint and pressure moving the handles together operates after the manner of a
pair of shears to bring the two parts at the opposite end of the instrument towards
one another. The passage P, is carried through one side of the instrument as
before to register with the passage or port carried by the pin or plug V.
It is not necessary to mount the automatic valve mechanisin in a
hinge. It
might be arranged as shown in Fig. 8. Also the support for the plungers might be
a rigid stock or frame instead of being hinged, as shown also in this figure, and but
three plungers are used. The space between them is sufficient to permit the tool
to be slipped upon the work without moving the sides apart. The valve
mechanism is in a fixed part of the frame and the passages i, l, communicate
directly through ports m, n, with the spaces at the inside of the piston heads C, C.
Ports b,, serve the same purpose as ports K, L, Fig. 1, so far as the automatic
valve action is concerned.
At A³, is indicated a stop or catch adapted to engage with one of the valves of
the piston-valve-movement so as to hold the parts in the position shown where the
air pressure will be applied to the pistons or plungers H, in a manner to hold the
same raised away from the work and ready for use. When it is desired to start
the tool into operation the stop A³, is removed by means of a lever applied in
convenient position on the handle A², as shown.
In Fig. 9, I have shown the application of the automatic valve movement to the
operation of a striker or hammer which operates a tool carrying bar or spindle.
Here one of the sets of pistons, as C, C, carries the striker, as M, which operates
on a tool carrying spindle N. Two separate hammers or strikers are provided
operating on straight lines meeting in the work which is represented at W, as a
bar or piece of metal subjected to the action of two swedges S4, S4, carried by the
spindles or rods N, N. The valve movements and parts supporting the swedges at
each end of the machine are mounted on a suitable base plate or support T, which
slides on a frame or table. By means of a right and left hand screw P4, applied as
shown to the moving parts, the valve mechanisms with the corresponding swedges
may be caused to open or close at will. When operating on a piece of hot metal
which has just been welded, as in an electric welding machine, the strikers or
hammers may be kept running all the time and the swedges gradually drawn in
towards the work by a turn or two of the feed screw as the work is reduced in
size. When the hammering is finished it is only necessary to reverse the feed fur
enough to move each hammer half the diameter of the work in order to remove it.
In this arrangement the small piston valve is placed underneath the two open
cylinders which contain the main pistons and the air is brought in to a port which
passes down one side and enters at the middle. In place of the swedges S', S*,
other tools operating on the work might be employed as is obvious.
While have described the use of a right and left hand screw for moving the
two parts of the apparatus Fig. 9, at opposite sides of the work, I do not limit
myself to such device as any other mechanical movement adapted to produce the
motion described will obviously answer the purposes when properly connected to
the slides carrying the pneumatic tool.
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:-
1. The combination in a pneumatic tool, of two or more plungers operating on
lines meeting at a common point or centre and each bearing or actuating a hammer

page_text: or equivalent device, as described, of a source of air, gas, steam or other fluid under
pressure, and a valve common to said plungers for controlling the passage of the
steam or other fluid so as to operate the plungers simultaneously.
2. In a pneumatic tool, the combination with two actuating plungers operating
on converging or meeting lines, of a valve movement independent of the motion of
the plungers for controlling the air, gas, steam or other fluid pressure which actuates
them.
3. The combination with the hammer or die carrying plungers working on
converging lines, of a stop or gauge adapted to rest on the work for adjusting
the hammers or tools to different sizes of work, as and for the purpose
described.
4. In a pneumatic tool, three or more plungers working on converging lines
and each carrying a hammer or die at its inner side, and a flexible pipe or
connection P2, for conveying air, gas, steam or other fluid under pressure to
operate said plungers and to permit the same to be moved circumferentially around
the work.
5. The combination with the tool carrying plunger, of the two reciprocatory
piston valves each controlling in its movement the exhaust and inlet for the other
so as to keep the said pistons or valves in continued movement while air, gas, steam
or other fluid under pressure is supplied to them, and connections from opposite
sides of the said tool carrying plunger to chambers or spaces of the valve system
where pressure and exhaust exist alternately, as and for the purpose described.
6. In a pneumatic tool, three or more tool carrying plungers H, H, H, working
on lines converging towards a common centre and all having pipes or passages
leading from opposite sides of the plungers and connecting each with a common
source of air, gas, steam or other fluid under pressure.
7. The combination in a pneumatic tool, of two or more plungers working towards
and from a common centre, a hammer or other tool carried by each and adapted to
engage with the work directly, a source of air, gas, steam or other fluid under
pressure common to said plungers, and an automatic valve mechanism operated by
the pressure of the fluid and controlling the controlling ports leading to the plunger
cylinders.
8. The combination with the parallel double acting pistons, of two pairs of ports
connecting the chambers in which said pistons reciprocate, each pair being controlled
by one of said pistons and forming alternately inlet and exhaust ports for the
other.
9. The combination of the double acting pistons C, C, having heads connected
by a rod passing through a diaphragm and working in cylinders or chambers open
at their outer ends, of a piston D, D, working in a chamber closed at its outer ends,
ports, controlled by the piston D, and forming alternately inlet and exhaust
ports for the piston C, and ports a, a¹, controlled_by_piston C, C, and forming
alternately inlet and exhaust ports for the piston D, D, as well as part of the
exhaust passages for the piston C, C.
10. In a pneumatic tool, the combination, substantially as described, of two arms
or supports A, B, jointed or hinged together, and each carrying one or more tool
operating plungers, as and for the purpose described.
11. In a pneumatic or similar tool, as described, the combination, substantially as
described, of tool operating plungers mounted on hinged supports jointed or hinged
to one another, and having a cut-off located in the hinge or otherwise located or
connected to the supports, as described, so as to be opened and closed as the arms
are moved for the purpose of applying or removing the tool.
12. The combination, substantially as described, of tool arms or supports
hinged together, and each carrying one or more tool operating plungers, and a
valve movement mounted in the plug or pin which connects the two parts of the
hinge.
13. The combination, substantially as described, with the automatic valve
movement having two pistons and connecting ports, of the passages K, L,

page_text: extending through the plug and connecting with ports in the two sides of the
hinge.
14. The combination, substantially as described, of the arms A, B, having ports
or passages 1, i, a pin or plug V, by which the two arms are hinged together,
pistons D, C, working in said plug or pin, and passages K, L, extending transversely
through the pin between the two pistons, said passages at their ends connecting
respectively with ports or passages in the two arms.
15. In a pneumatic tool, the combination with shaping tools or instruments
operating in the same line and on opposite sides of the work, of adjustable supports
for each tool, and a mechanism, such as a screw, for moving said tools to and from
one another simultaneously.
16. The combination in a pneumatic tool, of the two swedges or other instru-
ments S, S, applied to the work at opposite sides thereof, of the two strikers M, M,
carried by reciprocating pistons or plungers.
17. The combination with the tool actuating plunger, of a valve movement
controlling the air, gas, steam or other fluid pressure that actuates such plunger,
and a catch for engaging with the valve movement so as to hold the same in position
to permit the air or fluid pressure to keep the plunger lifted.
Dated this 4th day of December 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.