IMPROVEMENTS IN THE MANUFACTURE OF WELDED IRON AND STEEL TUBES, AND IN APPARATUS PROVISIONAL SPECIFICATION
Year: 1870

page_text: LETTERS PATENT to Andrew Stewart, James Stewart, and John
Wotherspoon, of Coatbridge, in the County of Lanark, North
Britain, Tube Manufacturers, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF WELDED IRON AND STEEL TUBES, AND IN APPARATUS
PROVISIONAL SPECIFICATION left by the said Andrew Stewart,
James Stewart, and John Wotherspoon at the Office of the
Commissioners of Patents, with their Petition, on the 23rd December
1870.
We, ANDREW STEWART, JAMES STEWART, and JOHN WOTHERSPOON,
of Coatbridge, in the County of Lanark, North Britain, Tube Manu-
facturers, do hereby declare the nature of the said Invention for “Im-
PROVEMENTS IN THE MANUFACTURE OF WELDED IRON AND STEEL TUBES, AND IN
APPARATUS THEREFOR," to be as follows:-
This Invention has for its object to improve and cheapen the manu-
facture of welded iron and steel tubes, by effecting in a single operation
(instead of two or more as hitherto employed) the bending of the flat

page_text: plate into the overlapped or butt-jointed tube or "skelp," ready for the
ordinary welding process.
"
And in carrying out the Invention the heated plate is first led by a
straight pair of guides in between a pair of plain horizontal rolls (that
is rolls with their axes horizontal), and is by them drawn into the
apparatus, and presented to a second pair of guides shaped so as to
partially bend down its two edges. The plate next proceeds between
a second pair of horizontal rolls, which act on its middle, whilst the
edges still move along guides, the under roll being convex, and the
upper one concave. After leaving the second pair of rolls the partially
bended plate continues its way along guides shaped so as to gradually
bend inwards the edges of the plate until they almost overlap or butt
together, and the edges are finally closed by the passage of the bended
plate or skelp," as it is termed, between a third pair of horizontal rolls,
which are both concave. A plug to prevent the plate from yielding
inwards is stationed inside the skelp, and just between the third pair
of rolls being held by a rod, extending forward from a bracket or block
projecting up between the open edges of the plate at a little distance
back from the said third pair of rolls. If preferred a pair of vertical
rolls may be introduced between the second and third pair of horizontal
rolls to effect part of the bending operation, instead of or along with the
guides. The various pairs of rolls are pressed together by means of
levers connected to their bearings, and acted upon by weights so that
the rollers can separate when any obstruction occurs, and thereby save
the machine from damage. A single weight is by preference applied by
means of connected levers to both journals of each roll, so as to insure
equality of action. The housings for the middle or second pair of rolls
are permanently fixed, but those for the first and third pairs are movable
by screws on inclined parts of the bed or main frame of the machine,
so that they can be adjusted to suit different sizes of tubes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Andrew Stewart, James Stewart, and John
Wotherspoon in the Great Seal Patent Office on the 22nd June
1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ANDREW 3
STEWART, JAMES STEWART, and JOHN WOTHERSPOON, of Coatbridge,

page_text: in the County of Lanark, North Britain, Tube Manufacturers, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of December, in the
year of our Lord One thousand eight hundred and seventy, in the
thirty-fourth year of Her reign, did for Herself, Her heirs and successors,
give and grant unto us, the said Andrew Stewart, James Stewart, and
John Wotherspoon, Her special licence that we, the said Andrew
Stewart, James Stewart, and John Wotherspoon, our executors, adminis-
trators, and assigns, or such others as we, the said Andrew Stewart,
James Stewart, and John Wotherspoon, our executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF WELDED IRON AND STEEL TUBES, AND IN APPARATUS THEREFOR," upon the
condition (amongst others) that we, the said Andrew Stewart, James
Stewart, and John Wotherspoon, our executors or administrators, by
an instrument in writing under our, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Andrew Stewart, James Stewart,
and John Wotherspoon, 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
in writing, reference being had to the accompanying Drawings, that
is to say:
Our said Invention has for its objects to improve and cheapen the
manufacture of welded iron and steel tubes by effecting in a single
operation (instead of two or more as hitherto employed) the bending of
the flat plate or "strip" into the overlapped or butt-jointed tube or
skelp ready for the ordinary welding process.
And in order that our said Invention and the manner of performing
the same may be properly understood, we hereunto append two Sheets

page_text: of explanatory Drawings to be herein-after referred to and representing
our improved apparatus. In these Drawings the same reference numerals
are used to mark the same or like parts wherever they are repeated.
Figures 1 and 2, on Sheet 1, of the Drawings are a plan and a side
elevation of the apparatus, and Figures 3 and 4, on Sheet 2, are trans-
verse vertical sections, as at the lines A-A, and B-B, in Figures 1
and 2; Figures 5, 6, 7, are sections of the guiding or shaping surfaces,
as at C-0, D-D, and E-E, in Figures 1 and 2.
In practically carrying out our Invention the heated plate or strip,
colored blue in the Drawings, is first led by a straight pair of guides 1,
in between a pair of plain or nearly plain horizontal rolls 2, and is by
them drawn into the apparatus and presented to a second pair of guides 3
shaped as shown best in Figure 5, to partially bend down its two edges.
The plate next proceeds between a second pair of horizontal rolls 4
which act on its middle part whilst the edges still move along guides,
the under roll 4 being convex and the upper one concave.
After leaving
the second pair of rolls 4 the partially bended plate continues its way
along guides 5, shaped as best seen in Figure 6, so as to gradually bend
inwards the edges of the plate until they almost overlap or butt together,
and the edges of the plate are finally closed by the passage of the
bended plate or "skelp," as it is termed, between a third pair of hori
zontal rolls 6, which are both concave. A plug 7 to prevent the plate
from yielding inwards is stationed inside the skelp and just between
the third pair of rolls 6, being held by a rod 8 extending forward from a
bracket or block projecting up between the open edges of the plate at a
little distance back from the said third pair of rolls 6.
In some cases, and if found preferable in practice, a pair of vertical
rolls may be introduced between the second and third pairs 4, 6, of hori-
zontal rolls to effect part of the bending operation instead of or along
with the guides 5. The various pairs of rollers are pressed together by
means of levers 9, as best seen in Figures 3 and 4, which levers being
centred upon the side frames are made with excentric parts to bear on
the buckle-shaped bottoms of rods acting as the holding down bolts of
the upper bearing blocks 10. The levers 9 are themselves acted upon
by weights 11 so that the rolls are not rigidly held together but can
separate when any obstruction occurs, and thereby save the machine
from damage. A single weight 11 is by preference applied by means
of connected levers 9 to both journals of each roll so as to insure equality

page_text: of action. As soon as the first end of the skelp gets through the
machine it is found to be advantageous to assist the subsequent action
by catching hold of it with the tongs or holder ordinarily employed in
drawing tubes and drawing it onwards by means of the ordinary endless
drawing chain upon the draw bench 14. The housings or side frames for
the middle pair of rolls 4 are permanently fixed to a bed plate or block,
but those 12, 13, for the first and third pairs are movable by screws 15
on inclined parts 16 of the bed plate so that they can be adjusted to suit
different sizes of tubes. The gearing whereby the various rollers
are driven will be easily understood from the Drawings. A pinion on a
first motion shaft 17 drives a spur wheel on the shaft of the lowermost
of the middle pair of rolls 4, and this spur wheel gives motion not only
to the roll 4 above but also to the rolls 2 and 6 by means in the latter
cases of intermediate wheels 18, 19, 20, indicated by dotted lines in
Figure 2. The intermediate wheels 18, 19, 20, are adjustable to suit the
different positions of the rolls 2, 6, one, 18, simply by means of a wedge
bencath the bearing, but the others 19, 20, which transmit motion to
the rolls 6 are fast on a short shaft carried by a piece 21 formed with
two eccentric enlargements, and these enlargements are fitted to turn in
bearings made for them in the framing. The eccentric piece 21 can
be adjusted by means of a lever 22 to cause the train of wheels to gear
together properly for different positions of the rolls 6 and can be fixed
by a screw and slot.
Having thus particularly described our said Invention, and the manner
in which the same is to be performed, we have to state that what we
believe to be novel and original, and claim as the Invention secured to us
by the herein-before in part recited Letters Patent is,―
1. The making of a "skelp" at one operation by means of improved
apparatus, the various parts of which are combined together substantially
as herein described and delineated.
2. The arranging or combining together of three pairs of rolls with
intermediate fixed guiding or shaping surfaces substantially as herein
described and delineated.
3. The arranging of the guiding or shaping surfaces which act in
combination with the rolls so as to bend the lateral edges of the plate
or strip downwards as herein-before described.
4. The fitting of the housings of some of the rolls on inclined beds to
allow of their adjustment as herein-before described.

page_text: 5. The applying of weighted levers in the manner herein-before
described for holding down the upper rolls.
In witness whereof, I, the said James Stewart, on behalf of the
said Andrew Stewart, myself, and the said John Wotherspoon,
have hereunto set my hand and seal, this Twenty-first day of
June, in the year of our Lord One thousand eight hundred and
seventy-one.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JAS. STEWART. (L.S.)