Improvements in or relating to the Manufacture of Sheet Metal Bends or Elbows.
Year: 1896

page_text: Date of Application, 4th Feb., 1896-Accepted, 7th Mar., 1896
COMPLETE SPECIFICATION.
Improvements in or relating to the Manufacture of Sheet Metal
Bends or Elbows.
I, CONRAD CARDUCK in Aachen, Empire of Germany, do hereby declare
the nature of this invention and in what manuer the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
The present invention relates to the manufacture of sheet-metal bends or elbows
with only one joint.
The process and the new device which has to be added to the press or stamping
machine for the application of the process, are described below.
In carrying the invention into practice by means of correspondingly shaped dies
in a suitable press or stamping machine, I produce a bent piece of sheet metal a
hereinafter referred to as a blank such as is shown in Figure 1 having a generally-
convex shape and at the joint edges two folds or depressions x projecting inwards,
and, at the part which is to form the outside or back of the elbow, a smaller
curvature than that of the elbow, when finished. The blank a is then placed under
a mandrel or core d hinged at band slightly raised by a spring c; the plungers e
press the mandrel d downwards, so that it forces the blank a into a die f
corresponding in shape to the outer half of the sheet metal elbow, (Figures 4 and 5)
so that the latter assumes the shape shown in Figure 6; then the stamp or die g
descends and closes the joint of the bend or elbow and gives it its finished shape
after which the elbow is taken off the mandrel d and the joint fastened by soldering,
rivetting or other means.
In order to manufacture, according to the process described, such elbows as
those used for connecting pipes of corrugated metal both ends of the elbow are for
a short distance made wavy as shown in Figure 7, by pressing waves at the ends of
the blank or elbow a.
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 1
claim is :-
1. The process of manufacturing a sheet metal bend or elbow with only one
seam or joint consisting of first pressing or stamping the sheet metal to form a
generally-convex blank such as a provided at the joint edges with two inwardly
projecting folds and having at the back or outside a smaller curvature than
the finished elbow then stamping the blank a by means of a mandrel placed in
it into a die corresponding in shape to the outer half of the elbow so as to
cause the edges of the seam or joint to approach each other and then closing the
joint by means of a stamp without any folds substantially as described.
2. For carrying out the process set forth in Claim 1 the arrangement of a press
or stamping machine by which a sheet metal piece or blank such as a with the aid
of a hinged mandrel such as d placed therein is pressed by two plungers e into a die
such as f corresponding in shape to the outer half of the elbow and the joint or seam
closed by the main stamp or die g of the same press substantially as described and
illustrated in the accompanying drawings.

page_text: 3. The combination and arrangement of parts constituting the complete press
attachment substantially as described and illustrated in the accompanying
drawings.
W1000
BOULT & WADE,
Agents for the Applicant.