Improvements in Apparatus for Drawing Tubes.
Year: 1887

page_text: Date of Application, 8th Oct., 1887
Complete Specification Left, 9th July, 1888
Complete Specification Accepted, 10th Aug., 1888
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Drawing Tubes.
We, WILLIAM ORR, Merchant, and PETER STUART BROWN, Manufacturer, both of
45 West Nile Street, Glasgow, in the County of Lanark, do hereby declare the nature
of this invention to be as follows:-
This Invention relates to drawing or forming tubes from lengths or strips of sheet
metal and whilst generally applicable it has more particularly for its object to draw or
form that class of such tubes as are of incomplete section, that is to say, as have an
opening or slot extending throughout their lengths.
The apparatus constituting the Invention consists of a mould or die which is made
in two parts and has through its interior a conical shaped passage the widest part of
the said passage being at that side of the mould at which the metal strip is introduced.
In the said conical shaped space or passage a similarly formed mandril is placed, an
annular space, the width of which is in accordance with the thickness of plate, being
left between the surfaces of the mandril and the mould or dic. From its upper or
lower part the mandril has a conical shaped feather projecting from it which feather
enters a groove made in one half of the mould or die, and the interior of the mandril
is cored or hollowed out from its narrower towards its wider end, the said core or
hollow opening out to the surface of the mandril at a point opposite to that from
which the conical feather projects. In one half of the mould or die a similar core is
made opposite the core through the mandril and into these cores the jaws of a pair
of tongs or grippers are introduced so as to catch the forward end of the plate or
strip.
The plate or strip may be used either hot or cold and it may be fed into the wider
end of the mould or die between rollers which may be so arranged as to bend and
partially form the tube before it is acted upon by the mandril and die, or the end of
the strip of metal may be partially bent into tubular form before it is introduced into
the apparatus.

page_text: With the arrangement of apparatus herein before described the entire length of the
metal sheet or strip is utilized there being no end or tail piece going to waste as is
the case with such apparatus as hitherto used.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.
Improvements in Apparatus for Drawing Tubes.
.
We, WILLIAM ORR, Merchant, and PETER STUART BROWN, Manufacturer, both of
45 West Nile Street, Glasgow, in the County of Lanark, 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 relates to drawing or forming tubes from lengths or strips of sheet
metal and whilst generally applicable it has more particularly for its object to draw or
form that class of such tubes as are of incomplete section that is to say, as have an
opening or slot extending throughout their lengths.
As seen in vertical section at figure 1 in front end elevation at figure 2 and in rear
end elevation at figure 3 of the accompanying drawings the apparatus constituting
the Invention consists of a mould or die which is made in two parts namely ani upper
part a and a lower part or bed b. The parts a and b have each feathers or wings c
formed at their sides by which the die or mould is supported in guides d formed on
side frames e and when the two parts are placed together there is a conical shaped
passage through the interior the widest part of which is at that end of the mould at
which the metal strip is introduced. In the said conical shaped space or passage a
similarly formed mandril is placed, the mandril having a jaw which grips upon
the upper part a of the die and holds the mandril in position whilst the arrangement
renders the mandril easily removable when desired. As shewn more particularly by
figure 2 an annular space, the width of which is in accordance with the thickness of
plate, is left between the surfaces of the mandril and the mould or die except at the
upper part where the mandril has a feather g entering a groove in the die or vice versa
and by which the slot in the tube is produced. The feathery is wedge shaped that is
to say it tapers or broadens out from the forward towards the rearward end of the
mandril the groove in the half a of the mould or die being similarly shaped.
shewn by figures 1 and 2 the forward end of the mandril is cored or hollowed out
and a recess h is also made at the forward end of the half b of the die these recesses
being for the purpose of receiving jaws of a pair of tongs or grippers i which are
introduced into them so as to catch the forward end of the plate or strip from which
the tube is being made and draw. it through the die.
As
As shewn by figures 4 and 5 which are hereinafter, more particularly referred to
the tongs have an arm or hook j connected to them which engages with an endless

page_text: sprocket chain k and by the operation of which the tube is drawn through the
apparatus.
The plate or strip may be used either hot or cold and it is fed into the wider end
of the mould or die between rollers l, m one of which the roller is centred in the
rear end of the mandril and the other m is carried in bearings in the lower half of
the die. The rollers l, m, are so arranged as to bend and partially form the tube
before it is acted upon by the mandril and die, or the end of the strip of metal may
be partially bent into tubular form by the arrangement of rollers shewn at figures 4
and 5 before it is introduced into the mould or die.
The said series of rollers consists of a pair of horizontal rollers n between which
the sheet or strip passes flat and by which it is fed between a pair of vertical rollers o
the action of which upon the sheet or strip is to partially form the tube by bending the
sides of the strip upwards. Between the rollers o a roller p is situated the said
roller acting on the centre of the strip to keep it flat. Nearer to the mould or die
there is another pair of horizontal rollers 9 the under one of which has a concave
and the upper a convex surface which rollers act to further bend up the body of the
strip or sheet and between the rollers 9 and the end of the mould or die another pair
of vertical rollers are situated to finally act on the sides of the strip before it enters
the mould or die. The train of rollers n to is or may be so geared together as to
be actuated by hand or power to feed the sheet or strip forward at the commencement
of operations and until the end of the strip is gripped by the tongs after which the
strip is drawn through the apparatus by the travelling chain and the train of
rollers n to r is then driven by friction.
With the arrangement of apparatus hereinbefore described the entire length of the
metal sheet or strip is utilized there being no end or tail piece going to waste as is
the case with such apparatus as hitherto used.
To counteract the tendency of the tube as it leaves the forward end of the dic or
mould to bend downwards we employ an apparatus consisting of a lever s and
roller centred upon it the lever itself being centred on the side frames of the
apparatus. A frame u, is also bolted to the upper part of the mould, the said frame
carrying a cross sliding frame v which has a tool w secured in it. The tool is formed
with a bulb point which passes into the interior of the tubo and a shoulder which
rests on the edges of the slot and prevents the tube from bending at that point. The
frame travels with the tube until it is stopped by the cross head u¹ of the frame u
and when that point is reached the levers is operated to raise the roller t under the
tube which then passes over the roller. By means of this arrangement of apparatus
a slight upward local bend is given to the tube which counteracts its tendency to
bend in the opposite direction.
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 :-
1. In apparatus for drawing tubes the combination of the mould or die and
mandril arranged and operating in conjunction with tongs or grippers substantially
as described with reference to figures 1, 2 and 3 of the appended drawings.
2. In apparatus of the class set forth a series of forming rollers arranged and
operating in conjunction with a mould or die, substantially as herein before described
with reference to figures 4 and 5 of the annexed drawings.
Dated this Seventh day of July 1888
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.