Machine for Spirally Welding Sheet Metal Tubes.
Year: 1889

page_text: Date of Application, 5th Nov., 1889
Complete Specification Left, 21st Nov., 1889-Accepted, 1st Feb., 1890
PROVISIONAL SPECIFICATION:
Machine for Spirally Welding Sheet Metal Tubes.
I, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad by The Spiral Weld Tube Co., a corporation
organized under the laws of the state of New Jersey, and doing business at East
Orange, New Jersey, and in the City, County and State of New York, United States
of America,) to be as follows:-
:-
The present invention relates to machinery for winding a long strip of sheet metal
spirally into a cylindrical pipe, and continuously welding the overlapped edge of the
strip where it makes a tangent to such pipe. In such machines the sheet metal is
heated by a gas jet concentrated upon the desired points by a box or furnace of
refractory material through which the edge of the skelp passes, and which is also
fitted against the curved portion of the pipe adjacent to the weld.
.
Heretofore, the weld has been closed by vibrating a hammer or anvil inside the pipe
in conjunction with a hammer vibrated upon the outside of the pipe; but in my
construction simplify this part of the machine by using a stationary anvil
protected from the heat of the gas flame by a mass of refractory material attached
to its side opposite the furnace.
دو
I also use adjacent to the weld, a vibrating "former pressed intermittingly
toward the stationary anvil to bend the straight skelp into a cylindrical form.
My. improvements also include a pipe mold provided with anti-friction rolls to
form and guide the pipe, and two pairs of feeding rolls, one of which is extended
part way across the skelp at the point where the skelp passes within the heating
furnace, and the other pair being adapted to operate upon the entire width of the
skelp, by location a little in the rear of the furnace, and the two pairs of rolls being
connected together by suitable gearing.
My improvements also include an auxiliary feed ring applied to the pipe, after it
is fully formed, at the point where it is discharged from the pipe mold, and rotated
positively by a connection with the skelp feeding rolls; the auxiliary feed ring being
provided internally with inclined friction rolls which press upon the exterior of the
pipe and operate when the ring is rotated in an opposite direction from the pipe, or
in the same direction at a faster rate, to positively draw the pipe from the pipe mold.
In such machines, a pipe mold is required to guide the bent metal from the anvil in a
cylindrical path beneath the anvil, to the furnace, and to the opposite side of the
anvil, to bring it adjacent to the heated edge of the straight skelp. The pipe
mold has heretofore been formed of a plain metallic shell, and all the feeding
appliances applied to the straight skelp or to the rear edge of the bent skelp operate
by pushing the same into the pipe mold, and great trouble has heretofore been
experienced by the crowding or expansion of the skelp within the mold, especially when
tho first end of a new skelp is started into the machine.
To prevent the sticking of the skelp within the mold, 1 have therefore devised a
mold provided at frequent intervals with anti-friction rolls set parallel to the
spiral seam of the pipe, by which the skelp is held effectively in cylindrical form.
The friction of the sheet metal against the mold is thus avoided, and the inclination
of the rollers operates to pull the rotating pipe forward within the mold as fast as
it is produced. The rolls may be inserted through holes formed in a cylindrical
shell, but to facilitate the supporting of their pivots at the various angles required
around the periphery of the pipe. I make the mold in a series of flat sections provided
with feet and clamped side by side upon the bed.
Each section is provided with a series of seats inclined parallel with the seam of

page_text: the pipe, and the rolls would be pivotted upon the seats by holts inserted in holes
in the seats. In each section the rolls are arranged about a circular opening
concentric with the interior of the pipe, and a series of such sections clamped sile
by side forms a species of hollow cylinder lined with inclined rolls, which touch the
exterior of the pipe at so many points that they not only assist in delivering it freely
from the machine, but serve to shape and hold it in the cylindrical form.
The feed rolls heretofore applied to the straight skelp have been arranged to grasp
the same as close as possible to the weld, but such rolls could not be extended across the
entire width of the skelp, as one edge of the skelp would be necessarily enclosed
in the gas furnace, adjacent to the weld, to secure its proper heating. The rolls could
therefore be provided with a housing at one end only, and their outer journals
could not be connected together because they would overhang the middle of the skelp.
Rolls thus constructed were deficient in the power to grip the sheet metal and push
it forward against the frictional resistance of the pipe mold, and I have therefore devised
an additional pair of feed rolls located in the rear of the furnace, and extended all the
way across the skelp, with housings at both sides of the skelp table, by which the
upper roll could be pressed firmly against the lower roll, and thus grip the skelp with
the desired force. I connect such rolls with the rolls previously used, by suitable
cog wheels, and operate both in conjunction, thus making a most efficient feed to
deliver the skelp with uniformity to the pipe mold.
Where a seam or other irregularity in the pipe tends to produce a sticking of the
same in the mold, it has been found desirable to furnish a feed outside of the mold,
which should operate by pulling the pipe axially from the same.
Such feed I have devised as a ring provided with inclined friction rolls pressed
elastically upon the exterior of the pipe, and rotated positively at such a rate in
relation to the obliquity of the rolls, as to draw the pipe forward from the mold.
The ring is preferably carried upon anti-friction wheels mounted on a frame adjacent
to the outer end of the mold, and is provided with cogs driven by a train of wheels
connecting it with the gearing of the skelp feeding rolls.
Such ring may be rotated in either direction, provided the obliquity of the rolls
attached to the ring be suitably adjusted to produce a longitudinal draft upon the pipe;
but it is preferable to rotate the ring in the same direction as the pipe is rotated in
the mold, in the process of formation, as the friction of the rolls then tends to assist the
rotation of the pipe within the mold; while the longitudinal draft is produced in such
case by rotating the ring faster than the pipe, and giving the auxiliary rolls a suitable
inclination.
With such auxiliary ring of rolls, the rear end of the skelp, after it has been wholly
delivered from the skelp feeding rolls, may be gradually drawn into the machine,
by the rotary and longitudinal movement imparted to the pipe by such ring.
Dated this 5th day of November 1889.
ALLISON BROS.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Machine for Spirally Welding Sheet Metal Tubes.
I, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the County of..
Middlesex, Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad by The Spiral Weld Tube Co., a corporation
organized under the laws of the State of New Jersey, and doing business at East
Orange, New Jersey, and in the City, County and State of New York, United States
of America), and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
j'
The present invention relates to machinery for winding a long strip of sheet metal
spirally into a cylindrical pipe, and continuously, welding the overlapped edge of the
strip where it makes a tangent to such pipe.

page_text: The invention consists in certain details of construction for facilitating the feeding
and welding operations, and will be readily understood by reference to the annexed
drawing, in which Fig. 1 is a plan of the machine with some of the minor details
omitted, as they are fully shown in the enlarged views, and would tend only to
confuse the drawing in Fig. 1; Fig. 2 is an end view of the bed and feed gearing;
Fig. 3 an elevation at the rear side of the machine; Fig. 4 a view at the opposite
end of the machine with the end-feed and heating appliances removed, with a pipe
mold for 24 pipe; Fig. 5 is a view at the same end of the bed showing the franie,
and train of gearing for actuating the end feed, the frame shown being suited for
24 pipe; Fig. 6 is a plan of the same in section on line x, x, in Fig. 5; Fig. 7 is
an elevation of the end-feed ring removed from the frame shown in Fig. 5; Fig. 8
is a vertical section at the center of the frame shown in Fig. 5, and including also
the feed-ring shown in Fig. 7; Fig. 9 is a plan of the feed-ring removed froin the
frame, as in Fig. 7; Fig. 10 is an elevation of one of the pipe mold sections
suited for 10" pipe; Fig. 11 an elevation of the intermediate section for the same
pipe mold; Fig. 12 a plan of the same in section on line y, y, in Fig. 11; Fig. 13 a
side elevation of the skelp feed-table upon the side opposite that shown in Fig. 4,
with the gib z in section upon the bottom bed plate; Fig. 14 is a plan of the
same; Fig. 15 a section through the feed rolls on line 1, 2, in Fig. 13; Fig. 16
is a section on line 22, 22, in Fig. 13, with a portion of the parts in the rear of the
section plane.
Fig. 17 is a plan of the anvil; Fig. 18 an elevation of the same npon the opposite
side to the furnace; Fig. 19 an end view of the same fitted up for a 16" pipe;
Fig. 20 a section of part of the "former" and jaw on line ¹, al in Fig. 21, which
is a view of the under side of the "former;" Fig. 22 is an edge view of the "former"
and jaw; Fig. 23 is a diagram showing the end of the bed, with the anvil for 16" pipe
and section of furnace adjacent thereto; Fig. 24 is a plan of the anvil and furnace
detached from their supports.
Dotted lines n, n², and n², are shown in Figs. 1, 3, 23, 24, to represent the
movements of the skelp through the machine.
In Figs. 1, 2, and 3, which are drawn upon a smaller scale than the other figures,
A is the bed, Ġ the base of the anvil, the arm of which projects within the pipe
during the welding operation and is covered by the "former" B, which is hinged
upon the post C and vibrated at its rear end by a reciprocating rod C. D is the
skelp table sustaining primary rolls D₁ which span the entire width of the skelp,
and secondary rolls which extend over a part only of the same, at the inner end
of the table, where one edge of the skelp is enclosed in the furnace. To prevent
obscuring the pipe niold beneath the "former," the furnace is not shown in Fig. 1,
but the line of the skelp, indicated by dotted lines n, shows where it passes into one
edge of the furnace, and under the former" B.
16
E is the driving shaft, E' the driving pulley, E' gears to drive a rear shaft F,
provided, as shown in Fig. 3, at one end, with a crank F¹ to actuate the "former "-
connecting-rod C. is the hammer, shown very narrow in width in Fig. 1, to
strike the weld between the furnace and the "former" B. The hammer head ip
shown rectangular in Fig. 3, and its holve has a journal provided in a box i, and
is actuated by a lever arm and a link j connected with a crank upon a shaft
(Fig. 1).
7.
The shaft is provided with a flanged pulley ¹ to which an independent belt
would be applied, as indicated by the dotted lines in Fig. 3. A rock shaft ***is
mounted adjacent to the shaft k, and has at one end a bandle n', and at the
opposite end an arm 2 carrying a tightening pulley n³ adapted to press upon
the belt when it is desired to actuate the hammer. At the other end, the
shaft is provided with a crank- pin F2 (Fig. 2) which is connected by a link a
with a slotted feed-arm a¹.
The feed-arm is oscillated upon a pivot a² by the link a, and is provided with
a feed-block a movable in the arm by link 6 which shifts the feed crank pin e
to and from the pivot a². A rock shaft H is provided to shift the feed block by

page_text: :
T
means of an arm a (Fig. 2) the shaft being provided with a handle H¹, the
position of which may be regulated by a latch H fitted to a toothed segment H³
(Figs. 3 and 4). The feed pin c actuates a pawl arm d by link d', and moves a
pawl d2 upon a ratchet wheel d³.
)
The ratchet wheel actuates a shaft e, which, by means of gears e¹ and e², transmits
motion to the primary feed rolls D; and by means of a gear e³ transmits motion to
auxiliary feed rolls (Fig. 1).
Universal joints are shown inserted in the rods which connect the feed gears
with the feed rolls.
The improvement in the anvil consists in fixing the same stationary within the
pipe, as shown in Fig. 4, the top of the pipe resting thereon, instead of making the
anvil vibrate.
The machine shown is adapted for making pipe from 12" to 24" diameter, and the
upper surface or head of the anvil is made changeable to suit the curvature of the
pipe.
G is the anvil, G' its removable head, G2 screws to secure such head in place,
and G³ a shank provided with foot G by which it is secured to the bed A.
The anvil is cooled by casting wrought iron water pipes G³ therein as shown in
Figs. 17 and 18, and the ends of the pipes being, in practice, connected with a water
supply to maintain a constant current through the same.
Another improvement in
the anvil consists in supporting upon the same a mass of refractory material y opposite
the mouth of the furnace, as shown in Figs. 23 and 24.
M' is the shell of the furnace shown supported upon a bracket M attached to the
bed A m² the refractory lining of the same, and m³ the cavity into which one or
more pipes m are inserted to supply mingled air and gas, under suitable pressure to
form a blow pipe jet directed toward the edges of the sheet metal which require
welding. One of these edges consists in the straight edge of the skelp indicated by
the dotted line 22, in Figs. 1 and 23, and the other edge is that of the coiled sheet
metal indicated by the dotted circle n² in Fig. 23, and which, in practice, passes close
to the front of the furnace, and between the same and the nearer side of the anvil.
The refractory material y is shown sustained adjacent to the anvil upon a
shelf gl
bolted to its under side, and being opposite the flame discharged from the cavity m³,
becomes highly heated.
In Fig. 24, the parallel lines indicate the path of the skelp as it approaches the
anvil, one of the lines passing through the edge of the furnace into the cavity m³.
The spiral dotted lines n* indicate the edges of the sheet metal when bent into a
curved form, while the dotted lines a show the edges of such coiled metal as it passes
between the furnace and the mass of incandescent material g.
In Fig. 4, B is a jaw secured rigidly to the "former" by bolts B2, but an
.alternative construction is shown in Figs. 20 to 23 inclusive, by which the jaw is
hinged to the "former." In Fig. 21, 62 are grooves formed in the under edge of the
"former" and the upper edge of the jaw; a round rod attached to the jaw by
screws (Fig. 22); and in Figs. 20 and 22, bolts are shown with hooked heads
in the under side of the "former," as shown in Fig. 21. The hooked bolts hold the
rod and jaw upon the "former," while the rod forms a hinge between the "former"
and jaws; so that the latter may turn to press evenly upon the curved surface of the
sheet metal. The feeding devices in such a machine have heretofore been confined to
the skelp table D, and to a pair of auxiliary rolls applied to the rear edge of the
cylindrical bent skelp below the "former," as shown in Figs. 1, 3 and 4.
In Fig. 3, the dotted line n* indicates, the bent edge of the skelp with the rolls
applied thereto, and in Fig. 4, the roll represents one of the auxiliary rolls within
the skelp, while the other is not shown as it lies behind the pipe mold.
Heretofore, the rolls upon the skelp table have been located at D upon the inner
end of the skelp table D, as shown in Fig. 1, to press upon only one edge of the skelp
and part of its width, as the opposite edge, indicated by the line n in Fig. 1, would be
enclosed within the furnace.
"The housing I of such rolls D could therefore be attached to the skelp table at its

page_text: little more than one half the circumference of the pipe, as shown in Figs. 10 and 11,
which also affords a better opportunity to view the welding operation.
The sections T may, however, cover more or less of the pipe at pleasure, or the
rolls may be mounted upon a cylindrical shell of the length desired for the mold.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is :-
1st. In a spiral welding machine, the combination, with a stationary anvil supported
inside the pipe, and a furnace adjacent to the outside of the pipe, of a mass of
refractory material attached to the anvil opposite the furnace, substantially as set
forth.
2nd. In a spiral welding machine, the combination, with a suitable bed, of a pipe
mold to guide the pipe, a stationary anvil supported within the pipe, a furnace to
heat the pipe, and a former reciprocated to and from the pipe opposite the anvil,
substantially as set forth.
"
3rd. In a spiral welding machine, the combination, with a suitable bed, of a skelp
table to guide the skelp, a pipe mold to receive and shape the skelp cylindrically,
anti-friction rolls sustained upon the pipe mold parallel with the spiral seam of the
pipe, an anvil and "former" to shape the pipe, and a furnace to heat the sheet metal,
substantially as herein set forth.
4th. In a spiral welding machine, a mold consisting in a series of flat sections T
provided with a series of inclined seats t³, and a series of rolls pivoted upon such
seats, and means for clamping the sections adjacent to one another upon the same axial
line, substantially as set forth.
5th. In a spiral welding machine, the combination, with an anvil and "former"
for shaping the pipe, of a furnace embracing the straight edge of the skelp adjacent
to the pipe, a skelp table sustained adjacent to the furnace, a pair of rolls upon the
skelp table covering a part of the skelp adjacent to the furnace, and an additional
pair of rolls upon the skelp table spanning the entire width of the skelp, with
housing secured to both edges of the skelp table, as and for the purpose set forth.
6th. In a spiral welding machine, the combination, with an anvil and "former"
for shaping the pipe, of a furnace embracing the straight edge of the skelp adjacent
to the pipe, a skelp table sustained adjacent to the furnace, a pair of rolls upon the
skelp table covering a part of the skelp adjacent to the furnace, an additional pair of
rolls upon the skelp table spanning the entire width of the skelp, with housing secured
to both edges of the skelp table, the universal coupling 1 for driving one pair of the
said rolls, and cog-wheels upon the table connecting the two pairs of rolls, as and for
the purpose set forth.
7th. In a spiral welding machine, the combination, with a pipe mould, a furnace,
and an anvil and "former" for shaping the pipe, of an auxiliary feed ring applied
to the pipe when formed, and provided with rolls adjusted to draw the pipe from the
mold as the ring is rotated, substantially as herein set forth.
8. In a spiral welding machine, the combination, with a pipe mold, a furnace, and
an anvil and former for shaping the pipe, of a skelp table with feeding rolls
attached thereto, feed gearing for actuating such rolls, a rotary ring R applied to the
pipe when formed, and provided with rolls adjusted to draw the pipe from the mold
as the ring is rotated, and gearing connecting the ring with the feed gearing of the
rolls, to operate both simultaneously, substantially as herein set forth.
9th. An end-feed for spiral welding machines, consisting in the frame P, the ring R
mounted thereon, the teeth Q formed upon the ring to rotate the same, and the series
of rolls mounted adjustably upon the ring, the whole arranged and operated as and
for the purpose set forth.
10th. An end-feed for spiral welding machines, consisting in the frame P, provided
with anti-friction wheels pl, the ring R fitted within such wheels, the teeth formed
upon the rim to rotate the same, and the series of rolls mounted adjustably upon
the ring, as and for the purpose set forth.

page_text: 11th. An end-feed for spiral welding machines, consisting in the frame P, provided
with the anti-friction wheels p² upon its opposite faces, a portion of the wheels being
mounted upon the adjustable blocks provided with screws, the ring R fitted within
such wheels, the teeth Q formed upon the rim to rotate the same, and the series of
rolls mounted adjustably upon the ring, as and for the purpose set forth.
12th. In a spiral welding machine, the combination, with a pipe mold, a furnace,
and an anvil and "former" for shaping the pipe, of a skelp table with feeding rolls
attached thereto, feed gearing for actuating such rolls, a rotary ring R applied to the
pipe when formed, and provided with rolls adjusted to draw the pipe from the mold
as the ring is rotated, teeth upon the ring to rotate the same, the shaft f connected
with the feed gearing, the arm Q pivoted on such shaft, the worm s and segment s¹
for oscillating the arm, and the change wheels g' pivoted upon the arm and adapted to
drive the teeth upon the ring R, as and for the purpose set forth.
a
13th. In a spiral welding machine, the combination, with a pipe mold, a furnace,
"former" for shaping the pipe, and suitable devices for feeding a skelp into the
mold, of the stationary anvil G sustained within the mold, the removable head G
fitted thereon, and the water pipes G' inserted in the anvil and removable head, for
cooling the same, substantially as herein set forth.
Dated this 21st day of Novemba 1000
ALLISON BROS.,
Agents for the Applicant.

page_text: outer edge only, by the bolts d (Fig. 13); and its upper arch (lettered 13 in Figs. 4
and 16) would be compelled alone to sustain the inner bearing of the roll nearest the
furnace. The bearings of the upper and lower rolls D' could not therefore, be
connected adjacent to the furnace, but would be separated by the gap I¹ (in Fig. 4),
to perinit the passage of the skelp.
In such construction the housing unavoidably yields at the end next the furnace,
and does not possess the strength to feed the skelp as positively as one in which the
arch of the housing is fastened rigidly by feet and bolts at both ends. I therefore
furnish the skelp table with additional rolls D located in the rear of the rolls D³ (the
top of Fig. 1 représenting the rear side of the machine) and far enough back to clear
the furnace, by which I am enabled to extend the housing J entirely across the skelp,
as shown in Figs. 1 and 15, and secure its opposite ends rigidly to the margin of the
skelp table, by bolts d'. By this construction I am also enabled to connect the rolls D¹
with cog-wheels d' at the outer end, in addition to the cog-wheels connecting
their inner ends like those upon the rolls D in Figs. 13, 14 and 16. In Figs. 13
and 14, the gears D upon the rolls D1 and D2 are shown connected by intermediate
gears d', and the lower roll D' is shown provided with the universal joint to
receive the rotary motion from the feed gearing by the shaft 7, and transmit it to the
rolls D¹.
:
In Figs. 15 and 16 the upper roll bearings are shown mounted in movable
heads suspended by bolts D from springs D³, and adjusted by means of
screws D6.
The skelp table itself is also shown in the various figures provided with means, as
the gib in Fig. 13, for adjusting it in different positions, but these details form no
part of my present invention.
In Fig. 13, a notch D8 is shown in the skelp table back of the rolls D², in which an
additional pair of rolls may be fitted by mounting a suitable housing upon the table,
to increase the grip of the feeding appliances upon the skelp.
The former is reciprocated upon the anvil, while the skelp is intermittingly fed
forward from the table, by the action of the pawl upon the ratchet wheel d³ ;
and a pipe mold is required to guide the bent metal from one side of the anvil, in a
cylindrical path (n2 in Fig. 23) beneath the anvil, to the furnace, and to the opposite
side of the anvil, to bring it adjacent to the heated edge of the straight skelp. With
the plain cylindrical pipe molds heretofore used, the feeding appliances applied to the
straight skelp, or to the rear edge of the bent skelp, operate by pushing the same
into the pipe mold, and great trouble has heretofore been experienced by the
crowding or expansion of the skelp within the mold, especially when the first end of
a new skelp is started into the machine. To prevent the sticking of the skelp within
the mold, I have therefore devised a mold provided at frequent intervals with anti-
friction rolls set parallel to the spiral seam of the pipe, by which the skelp is held
effectively in cylindrical form. The friction of the sheet metal against the mold is
thus avoided, and the inclination of the rollers operates to pull the pipe forward
within the mold as fast as it is produced.
The rolls may be inserted through holes formed in a cylindrical shell, but to
facilitate the supporting of their pivots at the various angles required around the
periphery of the pipe, I make the mold in a series of flat sections T (Figs. 10
and 12) provided with feet. T and clamped side by side upon the bed A by bars T
(Figs. 1 and 3). In Fig. 10, eleven seats are shown upon the section, while in Fig. 11,
which would be set intermediate with sections like Fig. 10, only ten seats are
provided by which arrangement the bearing of the rolls upon the pipe is alternated
in each of the sections. Each section is provided with a series of seats t³ inclined
parallel with the seam of the pipe, and the rolls would be pivoted upon the seats
by bolts inserted in holes in the seats. In, Figs. 1 and 3, the sections and rolls
are shown in conjunction, while Figs. 10, 11 and 12, show only the sections without
the rolls, and only one of the bolts * projected from one of the seats in Fig. 12.
Fig. 4, one of the sections is shown with its feet T¹ clamped by the bar 12 to the

page_text: bed A, with the section extending downward into a recess A' in the top of the
bed.
Where sections for smaller pipe are used like those shown in Figs. 10 and 11,
they would be supported upon the top of the bed by a plate T, the end of which
is shown in Fig. 10, with the bar T2 clamped thereto by bolts T. By this
construction the drilling of the holes in the separate mold sections is greatly
facilitated, and a mold of any length may be readily constructed by clamping a
suitable number of sections in proximity to one another upon the bed, as shown in
Figs. 1 and 3.
Where a scam or other irregularity in the pipe tends to produce a sticking of the
same in the mold, it has been found desirable to furnish a feed outside of the mold,
which should operate by pulling the pipe axially from the same.
Such feed have devised as a ring R provided with inclined rolls pressed
elastically upon the exterior of the pipe, and rotated positively at such a rate in
relation to the obliquity of the rolls, as to draw the pipe forward from the mold in
the direction of the arrow 3 (Fig. 9). The ring is preferably carried upon anti-
friction wheels p¹ mounted on a frame Padjacent to the outer end of the mold,
and is provided with cogs y driven by a train of wheels q' from the shaft.
For making different sizes of pipe, the frame P and ring R would be
altered in dimensions, and to rotate rings of different sizes by the same gearing, the
wheels g. as shown in Figs. 5 and 6, are mounted upon an arm Q pivoted upon
the sbaft, and adjustable around such shaft by a worms and segment s'.
By turning a hand wheel s upon the worm s, the outer gear upon the arm Q
may be adjusted to properly mesh with the cogs g upon a ring of any size.
The arm is shown in Fig. 6 formed with a slot Q2, to adjust the gear studs Q³.
at pleasure, so that various cog-wheels may be used to change the rate of feed.
As shown in Fig. 8, the anti-friction wheels pl are fitted in pairs upon studs at the
opposite sides of adjustable blocks p² which, by means of screws p³, may be moved
to fit the wheels snugly to the exterior of the ring R.
;
In like manner, the oblique rolls are mounted upon the ring R by adjustable
screws to press them upon the exterior of the pipe, which being of thin sheet
metal, springs sufficiently between the points of bearing of the six rolls 2, to give
them an elastic grip on the pipe.
The pipe, as it is constructed, rotates spirally within the mold and ring R, and it
is desirable that the end feed should not oppose such rotary motion, as it would
thus act in opposition to the feeding devices upon the skelp table. The ring R is
therefore rotated in the same direction (indicated by the arrows a in Figs. 4 and 7)
and the pipe and the rolls upon the ring are set at an angle contrary to those in
the pipe mold, and the ring is rotated at a little greater speed than the pipe itself
to produce an end-draft upon the latter, by the movement of the rolls over its
surface. The shaft, which actuates the end-feed, being connected by the gears e*
with the ratchet wheel d², operates to rotate the ring R intermittingly the same as
the other feeding devices. As the end-feed operates upon the finished pipe, it is
obviously effective in propelling the latter when the rear end of a skelp passes
beyond the feeding rolls D1, D2, and auxiliary rolls (upon the completion of a pipe
or the termination of a length of skelp), and is thus of great value in removing
the finished pipe from the mold; as its operation upon the pipe when it ceases
rotating, is much more rapid than when the pipe is turning in the same direction
with the ring R. A párt of the rolls in Fig. 1, nearest the furnace, appear
inclined in the opposite direction from those upon the opposite side of such line,
which appearance results from the exposure of the rolls in the bottom of the
mold, near the furnace, and those at the top of the mold at the opposite side of the
center line.
Such exposure of the rolls arises from the making of the mold with one side open
toward the furnace, to facilitate the application of the heat to the edges of the
pipe and skelp; for which purpose the mold sections T are made to embrace only a