Improvements in Pneumatic Punching and Rivetting Machines.
Year: 1894

page_text: Date of Application, 6th Apr., 1894
Complete Specification Left, 9th Nov., 1894-Accepted, 2nd Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Pneumatic Punching and Rivetting Machines.
I, HENRY JOHN WORSSAM, of Wenlock Road, City Road in the County of
London, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to pneumatic punching and rivetting machines of con-
struction more especially adapted for the rivetting of large copper vessels, but also
applicable for punching and rivetting generally. At the extremity of each limb
of a U shaped frame, having a deep gap, I fix a cylinder fitted with a plunger
and provided with suitable valves by which it can be rapidly put in communication
with a receptacle of compressed air or with a vacuum chamber.
When communication is made to the compressed air receptacle, which is
preferably arranged in or very near to the machine, the plunger is moved
rapidly forwards causing a punch or other tool in front of it to strike a blow.
When communication is made to the vacuum vessel the plunger is retracted.
Instead of employing a vacuum for this purpose, the cylinder may be fitted
with a differential piston subject always to pressure on the annular area in
front, sufficient to retract the piston when the pressure behind is relieved. Each
cylinder is fixed between a pair of parallel guide rods connected by crossheads in
front and rear.
By means of screws and nuts, the rear crossheads can be moved
forwards or backwards and fixed in position, the front crossheads being thus made
to approach towards or recede from each other. One of the guide rods in each
case has hinged on it a frame to hold a punching or a rivetting tool, which frame
can be turned aside on its hinge to have the tool inserted, removed, or exchanged
for another.
The machine operates in the following manner. The work to be rivetted up,
as for instance the junction of a pair of plates overlapping each other is placed
between the two crossheads which are made to clamp it firmly ;
one of the
plungers has in front of it a die which is pressed against the work on its one side
while a punch acted on by the other plunger punches a hole through the work,
and also may countersink the hole. The plunger being now retracted, a bolster is
substituted for the punch and a rivetting tool is substituted for the die, and while
the bolster is pressed against the work by the one plunger the rivet head is
formed by the stroke, or repeated strokes of the other plunger. By means of
suitable tools and bolsters the one plate which is overlapped by the other may be
indented on the one side so as to bring its other side flush with the surface of the
overlapping plate along the line of junction.
The frame of the machine is provided with suitable hooks or their equivalent so
that it can be suspended in various attitudes to suit the work to which it is applied,
and the valves of its air cylinders are connnected by flexible sliding or jointed
pipes to the air pump or pumps.
Dated this 6th day of April 1894.
ABEL & IMRAY,
Agents for Applicant.

page_text: Improvements in Pneumatic Punching and Rivetting Machines.
I, HENRY JOHN WORSSAM, of Wenlock Road, City Road, in the County of
London, 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 relates to pneumatic punching and rivetting machines of con-
struction more especially adapted for the rivetting of large copper vessels, but also
applicable for punching and rivetting generally, as I shall describe referring to
the accompanying drawings. Fig. 1 is an elevation partly in section, and Fig. 2 is
a sectional plan on X X of Fig. 1; Fig. 3 is a section of one of the valve boxes.
A pair of frames A, each in the form of an inverted U with a deep gap have
fixed between them a vessel B containing compressed air and a vessel C containing
rarefied air, the one being connected by a pipe b (which may be flexible or jointed)
to an air compressing pump or reservoir of compressed air, the other being
connected by a flexible or jointed pipe c to an air exhausting pump or to a vacuum
vessel. At the end of each limb of the U frame is fixed a cylinder D and D' each
fitted with a plunger d and d' respectively. Each cylinder communicates with a
valve box E and E¹ in which there is a slide valve controlling ports, leading
respectively to communications as follow. In the valve box E, port F com-
municates by pipe with the opposite cylinder D', port G communicates by
pipe g with the near cylinder D; port H opens to the air, and port I communicates
by pipe with the vacuum vessel C. The space in each valve box above the port
face communicates by a pipe e e² respectively with the pressure vessel B. Each
slide valve is manipulated by a rack toothed segment and handle KK. When
either valve is manipulated, the other is in a middle position closing all the ports,
the handle being upright.
Behind the cylinder D there is a crosshead L and in front of it there is a
crosshead M, these two crossheads being connected by guided side rods. The
front crosshead M is bored in the middle to receive a punching or a rivetting
tool m which can be inserted between it and the end of the cylinder D when the
plunger d is retracted. The rear crosshead L is provided with a setting nut 1 on a
bolt attached to the end of the cylinder D, whereby the front crosshead M is
adjusted as required. In front of the cylinder D' there is a crosshead M' which
is bored in the middle to receive a suitable bolster, die or rivetting tool m.
the crossheads M and M¹ have projecting bosses N N1, between which the plates P
which are to be rivetted together are firmly clamped the crosshead M being set
up by screwing up the nut 1. The frame being suspended by a link Q by which
it may be hung upright or in other attitudes according as the link Q is attached to
one or other of several cross bolts R, the punching and rivetting operation is
effected as follows.
Both
Assuming that the operator is in position to work the valve handle K, the
other handle K' being in middle position. Moving K to the right, he first opens
the port F, and compressed air from the valve box E flows by the pipe f to the
opposite cylinder D causing its plunger d¹ to advance against and hold up the
bolster, die or tool m¹. By a farther movement of K the port G is opened and
compressed air passes by the pipe g to the cylinder D, the plunger d is thus
propelled, its head striking the tool m and effecting punching or rivetting as the
case may be.
By moving the handle K towards the left the port G is put in communication
with H and thus compressed air from the cylinder D is allowed to escape to the
atmosphere. The handle K being then moved quite back to the left bringing

page_text: the valve to the position shewn in Fig. 3, the ports G and I put the cylinder D in
communication with the vacuum vessel C, and then the plunger d is retracted. A
series of blows may be thus delivered by the reciprocations of the plunger d, while
the other plunger d¹ remains stationary until it is withdrawn by working the valve
in E. Similar operations can be effected by working the handle K¹.
As the pressure and vacuum vessels B and C are arranged near the cylinders D D¹,
so that the air has not to pass through a great length of pipe, the strokes of the
plungers d d are rapidly effected and alternated, the punching and rivetting being
thus quickly performed. The plungers might be made differential so as to be
retracted by pressure on an annular area in front, the vacuum being thus dispensed
with; but as packing of the plungers would in that case be required, it is preferable,
when the plunger strokes are to be rapidly effected, to employ simple unpacked plungers
and vacuum for retracting them. The tools employed may be varied according to
the nature of the work. When flush rivetting is required, as for the interior of
coppers for brewing and the like, I employ in the first place a punch m with
bevilled shoulder and a die m¹ having a hole for the punch with a larger hole at
its mouth, thus forming in the plates Pa hole and countersink. After a rivet is
inserted, a suitable bolster is substituted for the die m¹ and a striker is substituted
for the punch m, this striker having a flat face to hammer and flatten the counter-
sunk head of the rivet on the one side of the plates P while the bolster forms the
button head of the rivet on the other face. As one of the plates P where it
overlaps the other is usually thinned at the edge so that there may be no abrupt
shoulder within the vessel, the face on which the striker has to act is somewhat
oblique and therefore the head of the striker is jointed to the stem by a spherical
joint which allows it to angle a little when it delivers the blow.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
A pneumatic punching and rivetting machine consisting of a U shaped frame
having at the extremities of its limbs a pair of cylinders provided with oppositely
moving plungers and connected by suitable pipes and valves with reservoirs of
compressed and rarefied air, substantially as described with reference to the
drawings.
Dated this 8th day of November 1894.
ABEL & IMRAY,
Agents for the Applicant.