An Improved Machine for Riveting, Punching, and Shearing Metal Plates.
Year: 1897

page_text: Date of Application, 17th Apr., 1897-Accepted, 29th May, 1897
COMPLETE SPECIFICATION.
An Improved Machine for Riveting, Punching, and Shearing
Metal Plates.
I CARL BALTHASAR BENDER of 18 Highview Road, Upper Norwood, in the County
of Surrey, Civil 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 :—
This invention consists in the application of the energy or ris-nira as well as the
pressures of gases, into which the grains, flakes or the slabs of more or less smokeless
gunpowder or of similar explosive compounds contained in suitable cartridges on
firing will be dissolved towards driving dies or other tools of riveting, punching or
shearing machines, and in the combinations of various parts for the purpose of
accomplishing this purpose.
These machines are selfcontained-the cartridge charge replacing the driving or
power machinery used in other riveting, punching or shearing machines.
I confine myself to describing my machines as used for riveting, those intended for
punching or for shearing being in principle of the same kind.
In the acc.mpanying drawings Figures 1 and 11 are sideviews and show the bodies
of my machines either in shape of clamps or of pairs of hinged or pivoted
levers A and A¹.
The hinged levers may be arranged to be either single-arm or else double-arm
levers.
In these figures d d are the places for the dies or other tools, and B and P the
places for the organs of the moving power.
Fig. 2 shows the barrel B of a clamp-machine in longitudinal section with the
piston or hammer placed therein and represented in the position before firing.
Figure 3 is the end view of the barrel.
The barrel B is suitably fixed to the end of one branch of the clamp. It could also
be made in one piece with the clamp. The barrel must have a sufficient metal-area
in cross-section in order to be able to bear without permanent change of its diameters
the pressures of the gases. These pressures can be ascertained and the diameters
calculated according to well known rules. The material of which the barrel is made
preferably is hard yet sufficiently ductile steel.
The barrel contains a cartridge chamber of suitable diameters and length. The
larger bore of the barrel is for the piston P which carries the die or other tools. This
bore is again widened out into a hollow cylinder forming a ring-shaped recess R",
containing a spring or springs S" placed around the piston.
At one end the barrel can be closed by a ring r' through which the piston passes
and by which it is guided.
At the other end of the barrel there is room for a reinforcing ring (, to be shrunk
upon the barrel-if found necessary-and also there is a screwed end or tenon by
which the barrel flange D (see Figures 4 and 5) can be fastened. The barrel-flange
could be made in one piece with the barrel. Or instead of being a separate piece and
screwed to the barrel B: the barrel-flange could also be shrunk upon the tenon.
Within the barrel bore the piston P is arranged to move. It is accurately turned
to fit the bore of the barrel and it is provided with suitable arrangements to prevent
the escape of the gases which being in a state of high tension and being hot would

page_text: soon score the piston if not secured against their escape. I use a cup-shaped
expansive and elastic gas-check, or grooves filled with wax, grease or paraffin, or both
or other means of obturation known by the science of gunnery either singly or
combined. Fig. 2 shows a gas check O which I turn into the metal of the piston by
washing the fine powder obtained with a trepanning tool out of the cut by a copions
supply of oil. In this manner the central part of the piston remains, the air spacing
of the powder charge is not much increased and useless expansion of the gases is
avoided.
Fig. 2 also shows four grooves in the neighbourhood of O.
If my machine is not one with a body in shape of a clamp but has a body with a
pair of levers, the barrel B will be attached to one lever and the piston to the other,
and soine means of adjustment, for instance by hinges h (as indicated by Fig. 11) will
be provided.
The piston has to be of such a diameter and of such material that the gases cannot
permanently deform the material by upsetting. 1 preferably use good tough steel for
the piston. I calculate the depth and the metal-thickness of the gas check so that it
sufficiently expands by the action of the gases but without receiving any appreciable
permanent set. The calculations should be undertaken both for the maximum gas
pressure and for the final pressures.
The diameter of the piston is further determined by the desire of utilizing as much
of the energy of the charges as possible and the expansion of the gases grows with
the piston area or the square of the piston diameter.
Figures 4 and 5 show the breech mechanism. Fig. 4 is a side view. Fig. 5 is the
end-view looking towards the cartridge chamber.
There exists now a great number of variously arranged breech mechanisms for
fire-arms.
The mechanism chosen by me is one by which the breech is closed by a plate
pivoting about an axis parallel to the axis of the barrel bore. The flange-plate D
bears the hinge-bolt No. 1 with nut and washers. This bolt is keyed to D; and a
spur-wheel W is keyed to the bolt. The flange-plate D is provided with a milled
circular slot for the shank and for the correspondingly shaped head of the
bolt No. 2. This bolt passes through the breech-piece or lever-plate E to which it is
held by a nut and a washer. The bolts 1. and 2. therefore receive the recoil pressure
of the charge and transfer it to the barrel and therefore to the body of the machine.
The lever or breech-piece E carries the lock or firing apparatus. The breech-piece is
provided with a handle and it carries the retainer-spring S" and its trigger T.
The nature of the lock is made clear by the Figures 4, 5, 6 and 7.
It is arranged in and around a hollow body or bolt F with a screw-end to fit the
tapped hole in E.
In the interior of F the firing bolt G can move. This bolt is combined with the
sliding nut N into one piece by the sliding pin P.
The sliding nut fits over the hollow body F, and the sliding pin can slide in the
longitudinal slots of the hollow body F (see Fig. 7). Fig. 6 shows a section
through G, F, p and N. The hollow body F also carries a spurwheel W₁ which
works into the fixed wheel W. The spur-wheel W₁ is made with an elongation with
screw-surfaces corresponding with similar surfaces made into the sliding nut N.
The spur-wheel W₁ can rotate around the hollow body but it is prevented from
sliding along its axis. The sliding nut N on the contrary can not turn, so that the
rotation of W may cause N and the sliding pin p with the firing bolt G thereto
attached to slide away from the breech-flange and in so doing to compress a spiral
spring S¹ slipped over the hollow body F and held in position by the end-nut N¹ with
the cap-tube H which close and protect the lock.
The spring S¹ being sufficiently compressed the retainer-spring S₁ can snap behind
a step of the firing bolt G and the spiral spring S¹ is held in tension until released
by a pressure upon the trigger T.
The office of the extractor K is made clear by Fig. 4 and by Fig. 5.
The cartridge-cases used by me may be made of metal or of other material

page_text: Preferably they are mounted with metal cups containing the anvil and a suitable cap
each. These cups being expanded by the gases close the breech and are renewed
for every shot. Other methods of obturation such as used in the science of gunnery.
may be arranged.
Finally instead of putting the piston-springs S within the barrels they may be
outside. In this instance the recess R¹ will be omitted, three or more bolts parallel
to the piston will be placed outside around the same, being screwed to: the barrel and
held by a ring which no longer is screwed to the barrel but is outside of it held
by the bolts which form an extension of the barrel.
My machines are operated as follows: Supposing one of them to have been fired :
the movement of the handle from position Vinto position X opens the breech, the
extractor spring K placed in a recess milled into the flange-plate D loosens the
cartridge-case which is then blown out by the gases. The piston-spring S carries
the piston back close to the end-surface of the barrel hore. By the same movement
the wheel W rolls upon the fixed wheel W, the screw-surfaces of W₁ press back the
nut N and compress the firing spring S₁; the firing bolt G follows the movement
of N, and being sufficiently withdrawn the hook of the retainer-spring Su enters
behind the surface qq of the firing bolt G and thus the firing spring remains
compressed.
Now the operator having placed a new cartridge the handle is put back to its first
position V and the apparatus is ready for firing.
The piece of work to be operated upon being placed between the dies, or else the
machine itself being shifted to suit the work and the body of the machine being held
against the rivet head already formed a pressure upon the knob of the trigger T
releases the spring S¹ which throws the firing pin against the cartridge-cap, so that
instantly and almost noiselessly the work intended is performed.
The manner in which a rivet head is formed is this: The piston moves freely say a
length equal to or somewhat more than the height of a rivet head and strikes with a
blow upon the hot and plastic rivet-iron.
Now in the theory of impacts the reduced mass-which can be ascertained-of
a moving body is that mass which would do the same work as this body, if that mass
were concentrated in the point of impact. The reduced mass of one of my clamps for
instance is many times greater than the mass of the moving piston. The mass in
rest can be made sufficiently great at will by placing enough metal near the points
of impact d d. It moreover is increased by the force of the operator pressing the
rivet head already formed against the metal plates.
The shock between the piston and the body of the machine, on account of the
interposition of the hot and plastic rivet, is an inelastic shock or concussion. If for
instance the reduced mass were twenty-nine times the mass of the moving piston
twenty-nine thirtieths of the energy of the moving piston would be available towards
upsetting the rivet. Besides this shock the pressure and the counter pressure by the
gases will act from the instant when the piston touches the rivet, so that impact and
pressure together do the work intended.
In a punching or shearing machine instead of a riveting machine the process is a
little different. Contrary to what takes place in riveting the resistance is greatest at
the beginning and what is needed is a sufficient pressure upon the piston at the
beginning of an operation and is easily obtained by making its diameter great,
and by reducing-as far as safely can be done-the airspacing of a sufficiently great
powder charge.
The charges of the explosive compounds depend upon their qualities and are soon
and best ascertained by a few experiments. Having for instance found the charge of
a certain powder for one size of rivet of a particular shape of heads: the charges for
rivets of other diameters are easily determined approximately; for their weights are
nearly in the same ratios as the weights of the rivets.
Much depends of course upon the degree and the uniformity of the heat of the
rivets which has to be well attended to. The same rule applies to punching or
shearing where also experiments in a short time give the desired data.

page_text: 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. A machine for riveting, punching and shearing metal plates arranged to be
operated by charges of more or less smokeless gunpowder or of similar explosive
compounds substantially as set forth.
2. In a riveting, punching or a shearing machine worked by an explosive compound
the combination of the pressure barrel, containing a chamber of smaller diameter for
the charge and a larger bore suitable for the piston, with the piston substantially as
-described.
3. In a riveting, punching or a shearing machine operated by the explosion of
gunpowder or similar compounds the piston spring or springs S, as and for the
purpose described and set forth.
4. In a riveting, punching or a shearing machine the combination of the cartridge-
chamber with a breech apparatus so arranged that upon the breech being opened the
enclosed gases blow out the empty cartridge and escape through this breech,
substantially as herein described and set forth.
.
5. The combination in the breech-apparatus of the leverplate E with the bolt No. 2
moving in a T slot of the barrel-flange D as and for the purpose set forth and
described.
6. The combination in the breech-lock of the hinged
spur-wheels W and W' as and for the purpose set forth.
Dated this Seventeenth day of April 1897.
breech-plate E with
CARL BALTHASAR BENDER.