Improvements in Spirally-formed Metal Pipes and Process of Making the same.
Year: 1886

page_text: "
Improvements in Spirally-formed Metal Pipes and Process of
Making the same.
I, JOHN B. Roor, of Portchester, County of Westchester, and State of New
York, United States of America, Manufacturer, 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 generally to that class of metal pipes which are made
from strips or blanks of sheet metal wound spirally into cylindrical form and
having their opposite edges joined together along a spiral seam.
The said invention consists in the process, hereinafter set forth, of spirally
winding a blank into cylindrical form with its opposite edges overlapping,
bringing such edges to a welding heat just before, or as they are brought
together and without heating the body or central part of the blank, and then
welding such overlapping and heated edges together by pressure suitably applied
to the edges at or near the point where they are brought in contact.
invention also consists of the pipe thus produced.
The
In practicing this invention, strips or blanks of sheet iron or steel will be used.
These strips will be wound spirally, by machinery specially adapted to this purpose,
into cylindrical form with their opposite edges overlapping. At or near the point
where such edges come together as the blank is fed forward and brought into
cylindrical form, and in the angle formed by the already curved edge and the
opposite straight edge, is applied a beating jet of sufficient intensity to quickly
bring such edges to a welding condition. As these edges are heated they are
passed between welding devices arranged to apply such pressure as is requisite to
force the heated edges into intimate contact and firmly weld them together.
One form of mechanism which is adapted for making such pipe is shown in the
accompanying drawing in which
Figure 1 is a plan of the machine;
Figure is an elevation.

page_text: pincher shaft is supported in suitable bearings D and is bored out and encloses and
supports the main shaft. The main shaft is connected with any suitable driving
apparatus adapted to give it continuous rotary motion; while the pincher shaft is
driven so as to have a spirally-reciprocating motion.
E E are clamping or pinching jaws, which are pivotally mounted upon the
pincher shaft and are provided with clamping faces F F and shaping heads GG,
and are actuated to open and close by cams H on the main shaft and suitable
connecting rods extending from such cams to the inner ends of the clamps.
II are hammers pivotally mounted upon the same supports as the clamping
mechanism. These hammers are connected so as to operate together, striking
simultaneously upon opposite sides of the blank, and they extend forward so that
their blow will be delivered upon the edges of the blank at the point where such
edges come in contact and where they are heated. The hammers are operated by
pawl J mounted upon the upper clamping jaw, and adapted to engage with the
notched sleeve K of the actuating arm L. As the clamping jaws close, this pawl
engages the notched sleeve and turns the actuating arm to force the hammers
together, the tripping arm M on sleeve K disengaging the pawl just before the
hammers come together, and the spring 'N retracting them after they have struck
their blow.
O is a former for supporting the blank as it is shaped and assisting in giving it
cylindrical form, P being guides located along the spiral path of the blank for
guiding the blank.
Qis a blow-pipe which is located so as to direct its flame directly upon the
overlapping edge of the blank in the apex of the angle formed by such edge; this
blow-pipe being surrounded by a suitable furnace structure R of refractory
material arranged so as to confine the heating flame to the edges of the blank
at and near to the point of their junction. This furnace structure, as well as the
clamping jaws, is furnished with water pipes S arranged to permit the circulation
of water about these parts for the purpose of preventing their becoming unduly
heated. T is a section of finished pipe.
The blank U is fed through the furnace at the proper inclination and coiled into
cylindrical form with its edges overlapping, it being held in position by the former
and the guides upon it, usually also, the blank is passed over a guide table suitably
constructed and arranged to support it and hold it at the proper inclination.
With the mechanism in operation, the pincher shaft moves forward along the
spiral path of the blank and returns, for each revolution of the main shaft, so that
the first motion of the pincher jaws is to close upon the edges of the blank. The
pinchers then move spirally forward carrying the blank with them and laying
and shaping it spirally, their shaping heads and the former serving to shape it
cylindrically and to keep the formed pipe of uniform size. After moving a short
distance forward, the clamping jaws stop and open, and are thereupon retracted
over the blank to their first position. This forward feed of the blank is regulated
to correspond with the time necessary to properly heat its edges previous to
welding, such feed being longer or shorter according as the blank is thick or thin.
As the blank is seized by the pinchers, the hammers are caused to act and strike
a blow upon the edges of the blank at the point where such edges are brought to
a welding condition, so that the clamping jaws seize the welded seam and by their
clamping or pinching action tend to still further form or finish the seam.
action of the machine is wholly automatic and continuous, and the finished pipe
may be made in any desired lengths it being understood that the blank is made
continuous by welding the commercial lengths together end to end. If desired
the gases which supply the blow-pipe may also carry a flux as an adjunct to the
welding.
This
This form of machine may be modified in many respects, and machines
substantially different may be employed for making such pipe, but I prefer that
here shown, as being the best.

page_text: The advantages of making spiral pipe this way, that is by heating the edges
only of the blank, are various. Thus the main body of the blank remains in its
normal condition of strength and finish and is practically unaffected by the heat
applied to its edges; and, as this kind of pipe is generally formed from sheet metal
made hard, compact, and smooth in its manufacture, it follows that the pipe made
in this way will have all the possible strength of the metal, and that the body of
the metal will not be softened and its strength lost by bringing it to welding heat
and allowing it to cool, as has been the case heretofore.
Again as is well understood, when a flat blank is wound up spirally and upon
itself it tends to form a cone and when it is desired to form a cylinder the blank
must be in some way expanded as to its outer edge and contracted as to its
inner edge. With blanks heated throughout their whole width, the tendency,
particularly with thin metal, is to cause the blank to bucklo or bend out of shape;
but when the edges only of the blank are heated the bending and shaping is
confined to such edges, which are compressed or expanded as may be required and
smoothed out and finished, and the body of the blank is in no way undesirably
affected.
Other points of advantage may be mentioned; and those inherent in the process,
such as the saving in heating fuel and the saving in time resulting from more
rapid heating by the use of a concentrated flame or jet, are important in making
the herein described process and product valuable improvements in the art to
which they belong.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
First. The herein described process of making metal pipe, which consists in
spirally winding a strip or blank of sheet metal into cylindrical form with its
opposite edges overlapping, bringing the overlapping edges only of the blank to a
welding heat, and then welding such edges together by the application of pressure
thereto, substantially as described. .
Second. The spirally formed metal pipe hereinbefore described, made by winding
a blank spirally into cylindrical form, heating the overlapping edges of the blank
by the application of heat to the edges only, and then welding such edges together
by requisite pressure, substantially as described.
Dated this 3rd day of August 1886.
HASELTINE, LAKE & Co.
Agents for the Applicant.