Improvements in the Mode of and Means for the Manufacture of Curved Tubes.
Year: 1894

page_text: Date of Application, 3rd Oct., 1894-Accepted, 3rd Nov., 1894
COMPLETE SPECIFICATION.
Improvements in the Mode of and Means for the Manufacture of
Curved Tubes.
We, JAMES MCDOUGALL, and GEORGE HENRY MCDOUGALL, of Hope Patent
Tube Works, Wednesbury, in the County of Stafford, Manufacturers, do hereby
declare the nature of our said invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
Our invention has for its object improvements in the mode of and means for the
manufacture of curved tubes which enables us to make such curved tubes much
more regular in their external and internal configuration and also much cheaper
than by the old method of bending over a die on a smith's anvil or by the well known
friction wheel action. These tubes being used mostly for air passages in parts of
marine boilers and other grates, it is highly important that the passage should be
kept to its full arca and that no irregularities or obstacles should exist in the
passage.
In order that our invention may be clearly understood and more easily carried
into practical effect we have annexed hereunto a double sized sheet of drawings
upon which is illustrated our mode of proceedure for making such tubes both singly
at one operation and more than one at each operation.
Figure 1., is a front elevation of the tools used in the operation of bending.
Figure 2., is an end elevation of Figure 1.
Figure 3., is a plan of the upper tool B showing the usual square teat 6 which is
cast or forged thereupon for entering the head A of the screw or other equivalent
press, through which the action for bending is transmitted.
Figure 4., is a plan of the lower tool E with the upper tool B removed.
Figure 5., is a cross section through both tools on the line 1-2.
Figure 6., is a cross section through a lower tool E when formed to produce two
bent tubes at one operation.
Figure 7., is a side elevation and section of a tube K drawn in the usual
nanner through dies ready to be operated upon by my new mode and means..
Figure 8., shows a broken off tube curved after passing through the dies such as
is suitable for the purpose of marine furnaces as before mentioned.
The tube K as seen at Figure 7 is such as is drawn through ordinary dies on a
draw table as well understood in the trade. E is a special tool formed with its
broad base swelled out by e and e³ for standing upon the bottom of a screw or
other such like press.
The upper portion of this lower tool E is hollowed out as
shown by the curved line e', e, e, and a groove e' is formed around the curved edge
thereof as seen in the section Figure 5. There is also a hole e" which passes
through the tool to carry away the scurf. The upper tool B has its bottom edge
formed to correspond with the curve of the lower tool E and a groove ³ running
around the same to correspond with the groove e' in the lower tool. The upper
tool is screwed to the head A of the press in the usual manner. The cotte hole b³
is for the convenience of moving the tool. The straight tube as seen at Figure 7
is laid upon the lower die E and the upper die B is brought down upon it which
bends it to the desired curve without any further hammering or forming. The
sides of the groove b² prevents any outward buckling of the tube while the bending
proceeds.
The inside of the tube K may be filled with sand or other similar material while
being bent. It will this be seen that we obtain a regular configuration by enclosing

page_text: the whole of the surface of the stube while being curved within the sides of the
curved dies top and bottom.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner 'the same is to be performed we declare that what we
claim is:-
:-
纂
The improvements in the mode of and means for the manufacture of curved
tubes substantially as and for the purpose herein set forth and shown upon the
accompanying drawings.
Dated this 1st day of October 1894.
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent for Applicant.