An Improved Hydraulic Sheet Metal Bending Machine.
Year: 1896

page_text: Date of Application, 16th Dec., 1896-Accepted, 27th Mar., 1897
COMPLETE SPECIFICATION.
An Improved Hydraulic Sheet Metal Bending Machine.
I, SVETOZAR NEVOLE of IV Wiedener Gürtel 18, Vieuna in the Empire of
Austria, 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 has for its object an improved hydraulic machine for bending-
sheet metal, by means of which various kinds of boiler plates of iron, steel, copper
or the like may be edged, flanged and more particularly bent. in various ways.
The machine, which is shown in Figures 1 and 2 of the accompanying drawings.
in sectional side elevation and front elevation respectively, consists of a frame of
cast iron, on the upper part of which the pressing cylinders are arranged, whilst the
under part is formed as a table to receive one half m of the press swage.
One or two vertically acting plungers a serve for retaining or holding fast the
parts to be bent, which plungers are set in movement by meaus of a pressure pipe i
and a controlling device b, and are pressed against the plate, and after the beading
operation is completed, are forced back again by the action of springs.
The bending of the plate is effected by the obliquely arranged plunger c which
at its lower end carries the second half n of the press swage, and is prevented from
becoming displaced by side guides l. This plunger is pressed against the edge of
the plate which is to be bent by the action of water entering at the point d under
pressure when admitted by a controlling device f, which water presses on the upper
surface of the plunger.
As the small annular under surface of this plunger constantly stands under
pressure through pipe g, the plunger is automatically again raised when the-
controlling device is reversed so that the water can escape over the plunger.
In order to arrest the stroke and prevent the plunger exceeding in its descent a
certain depth, a small longitudinally bored rod h opening freely to the outside is
employed, which, at the deepest position of the plunger c, allows the water under
pressure to escape into and through the bore in said rod h when the washering k
moving with the plunger has uncovered the lower end of the tube, or ports formed
near said end, whereby any continuation of the movement of the piston downwards
is prevented, as the water under pressure escapes, and the constant pressure
upwards on the annular under surface of the plunger of the water from the pipe g.
tends to raise the plunger.
Finally, two horizontal plungers are arranged on the frame, one or other of
which, or according to requirements, both, serve for retaining the already bent
plate, and preventing its flinching backwards. These pistons are operated by a.
controlling device s.
As compared with the ordinary arrangements having bending plungers parallel
to or vertical with the direction of the flexion, the oblique arrangement of this.
plunger affords the following advantages:-
1. A considerably reduced strain on the machine, allowing of reduced
dimensions.
2. A rational bending of the edges, friction by the swage being avoided as far
as possible, and consequently any stretching of the sheet or plate during the
bending operation is avoided, which is unavoidable in closed swages where the
pistons are arranged vertically.

page_text: 3. The treatment of bends inaccessible to other arrangements. Thus, for
instance, dome cupola flangings may be carried out very rationally, as the com-
pressed arrangement of the pressing cylinders, as well as the oblique direction of
the plunger, not only renders possible the holding fast or retaining of a rolled
sheet-metal-cylinder (see p, Figure 2, from the inside), but also an entire irregular
flanging without further trouble.
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 :-
An improved hydraulic piate or sheet metal bending machine, characterized by
one or more retaining plungers (a) and by an obliquely placed pressure plunger (c)
forming an acute angle with the plane of the sheet metal plate, substantially as
herein before set forth.
Dated this 12th day of December 1896
WM. P. THOMPSON & Co.,
Of 6 Lord Street, Liverpool, Agents for the Applicant.