Hydraulic Riveting Machine.
Year: 1893

page_text: Date of Application, 5th Oct., 1893-Accepted, 11th Nov., 1893
Hydraulic Riveting Machine.
I, ADOLF HOFFMANN, Engineer of Kalk, near Cologne, Mittelstrasse No. 12 in
the Province of Rhineland, Germany 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:-
In the hydraulic riveting-machines in use up to the present the construction is of
such a kind that the stamp serving to press the edges of the plate about the rivet
that is to be pressed, precedes by a certain length the stamp that presses the rivet-
head. As soon therefore as this distance has been reached the rivet-stamp must of
necessity begin to work, no matter whether the plates are pressed close to each
other or not.
In order to obviate this disadvantage I have worked out a new construction in
hydraulic riveting-machines, which is represented in annexed drawing.
Fig. 1 shows the machine in a state of rest; both stamps are in their initial
position.
In Fig. 2 the stamp which presses the plates together is in action; the rivet-
stamp however is still in its initial position.
In Fig. 3 the riveting-stamp is just forming the rivet-head.
The plate-stamp and the rivet-stamp of my machine are acting independently of
each other, being made possible by the following construction:
To the riveting-block A is fixed the bottom B, the front end of which is turned
into a cylindrical neck so as to serve as guide to the piston C which has the rivet-
stamp E at the end of its continuation D. This piston is bored out lengthways
with a bore of equal diameter and lying in the same direction as the bore of the
bottom-piece B. In this hollow cylindrical space formed in common by both parts,
the piston F moves, having on its continuation a piece of specially shaped iron G,
that slides on the continuation D of the piston C and at its front end is formed like
a ring, so as to allow the rivet-stamp E to pass through. To this ring-shaped end
the hollow stamp or press-ring H, which serves to press the edges of the holes in
the plates a and b about the rivet c is fitted.
Through the passage J the water from the hydraulic press enters behind the
piston F and pushes it forward together with the stamp H fixed to it, so that the
latter tightly presses the plates a and b about the rivet c. Then water is allowed
to act through the passage K on the ring-shaped surface d of the piston C bearing
the rivet-stamp E, so that the end of the rivet-shaft which projects through the
plate a is pressed into a head.
When the riveting is finished the water in the chambers L and M is let out by a
suitable distributing valve motion and hydraulic pressure allowed to act through
the passage e on the pistons N and O, thereby bringing back the pistons C and F
to their initial position so that the machine appears again as in Fig. 1.
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:
Hydraulic riveting-machine thereby distinguished that the piston C bearing the
vivating stamn E is aimultaneously guided by the bottom-niece B and the niston F

page_text: bearing the figured iron G together with the plate-stamp H; the piston F itself
being guided by the bottom-piece B.
Dated this 29th day of September 1893.
For ADOLF HOFFMANN,
Bernhard Brockhues.