IMPROVEMENTS IN MACHINERY FOR MAKING SKELPS FOR THE MANUFACTURE OF WROUGHT IRON AND STEEL TUBES
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Charles Edward Smith at the
Office of the Commissioners of Patents, with his Petition, on the
17th May 1878.
I, CHARLES EDWARD SMITH, of Wednesbury, in the County of
Stafford, Manager of Works, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MACHINERY FOR MAKING SKELPS FOR THE
MANUFACTURE OF WROUGHT IRON AND STEEL TUBES," to be as follows:-
My Invention consists of the construction and arrangement herein-
after described of the parts of machinery for bending strips of heated
wrought iron or steel into skelps or unwelded tubes, whereby the manu-
facture of the said skelps is facilitated and simplified.
The said bending machinery consists essentially of a pair of dies or
tools, the lower die or tool being fixed on the bed or foundation plate of
the machine, and the upper die or tool being worked by preference by
hydraulic power.
The said dies or tools are of a length equal to the length of the skelp
mada and barn from farnations nomoly first to dish
excite a

page_text: trough form to the strip, and next to convert the dished strip into
a skelp or unwelded tube.
The said dies or tools when used for making gas tube skelps are
constructed as follows:- -The lower fixed die or tool is furnished on its
upper side, and passing from end to end, with a concavity or depression 5
of a nearly semicircular figure, and of a size proper to give the trough or
dish figure to the strip of wrought iron or steel, and parallel with this
concavity or depression is another smaller concavity or depression, in
which the dished strip is made into a skelp. The upper moveable die or
tool has on its under side a convexity of the same figure as and situated 1
opposite the first named trough-shaped concavity in the lower die or
tool, and the said upper die or tool is also furnished with a concavity of
the same figure as and situated opposite the smaller concavity in the
lower die or tool.
When the upper die or tool is brought down upon the lower die or 1
tool, the convexity of the said upper die enters and nearly fills up the
corresponding shaped concavity on the lower die, and the finishing parts
of the said dies enclose between them a nearly cylindrical space.
In using my improved machinery for making gas tube skelps, the
heated strip of wrought iron or steel is placed over the dishing part of 2
the lower die, and the upper die is brought down upon it. By the
operation of the upper die its convex part forces the strip into and gives
it the figure of the dishing portion of the lower die.
The trough or dish shaped strip while still hot is transferred to the
finishing part of the lower die, and placed on its edge in the finishing 2
concavity of the said lower die, and by the descent of the upper die, the
dished strip is made to take the figure of the finishing portions of the
two dies, and a skelp is thereby formed.
In making lap jointed skelps for the manufacture of boiler tubes I
make the dishing portion of the lower die of a semi-elliptical figure, the
convex part of the upper die having a corresponding figure, and I make
the finishing portion of the two dies of a slightly concave figure. After
the heated strip has been dished in the dishing portions of the dies it is
placed on its edge in the finishing part of the lower die, and a mandril
placed within it. The upper die is then brought down several times
upon the dished strip, the strip being turned after each blow whereby

page_text: the said dished strip is bent around the mandril, and a lap jointed skelp
formed.
When I work the upper die or tool by hydraulic power I prefer to use
two hydraulic cylinders, and connect the said upper die or tool to the
rams of the said cylinders. The said hybraulic cylinders are carried by
standards or uprights bolted to the bed plate of the machine.
Although I prefer to use hydraulic power for working the upper die
or tool yet the said die or tool may be worked by steam or other power.