Improvements relating to the Electric Welding of Tubes and to Apparatus therefor.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements relating to the Electric Welding of Tubes and to
Apparatus therefor.
I, OTTO PARPART, of 203, Noyes Street, Cleveland, Ohio, United States of
America, Mechanical Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to the electric welding of tubes. According to a broad
view thereof, it consists in the combination of two electric current conducting
devices, electrically disconnected from each other, respectively connected with
opposite electric poles, and adapted to be in contact respectively with opposite edge
portions of but not upon the longitudinal tube joint, together with two tube com-
pression devices which receive the tube between them, and which exert longitudinal
feeding draft on the tube.
According to a more detailed view thereof, the preferred means which I employ
in embodiment of the above described principle of the invention, consists of the
combination of two electric current conducting rolls electrically disconnected from
each other, respectively connected with opposite electric poles, and which press
respectively against opposite edge portions of but not upon the longitudinal tube
joint, together with two tube compression rolls which are electrically disconnected
from said electric current conducting rolls and which receive the tubes between
them
In proceeding according to the said preferred way of carrying out the principle
of my invention-though it should be clearly understood that various other ways
and many different detail means, may be employed in substitution for my said pre-
ferred way and detail means-I take sheet metal tube blanks, which have been
previously rolled into tubular form having a longitudinal open seam or joint
throughout their entire length; and I introduce such a blank into a machine which
has the previously described parts, and submit it to the action of such parts. The
electric current conducting devices heat the meeting parts of the longitudinal tube
joint to a welding heat; while the compression devices force together such heated
portions of the tube joint, and effect a complete weld thereof; the tube being
automatically fed lengthwise through the machine by the described parts,--either
exclusively by them, or by them conjointly with additional devices adapted to
exert a longitudinal feeding draft on the tube.
I think it of advantage to locate the said parts so that the axial line of contact
of the current conducting devices may be slightly in advance in the line of feed,
of the vertical plane passing at right angles to the tube joint and passing through
the center of the axes of the tube compression devices; whereby the greatest com-
pression of the tube takes place after the current has once passed through the tube
FD... 97

page_text: joint. Suitable guide or guides along the line of feed of the tube may guide such
tube into or through the machine.
The invention is especially adapted for electrically welding tubing for bicycles.
Dated this 24th day of December 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements relating to the Electric Welding of Tubes and to
Apparatus therefor.
I, OTTO PARPART, of 203, Noyes Street, Cleveland, Ohio, United States of
America, Mechanical Engineer, 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:—
The object of my invention is to provide a machine for electrically welding the
meeting parts of metal-being particularly adapted for welding the longitudinal
joints of bicycle tubes. The nature of the invention will be hereinafter more par-
ticularly described with reference to the accompanying drawings which show certain
mechanism embodying the said invention, such mechanism constituting but one of
various mechanical forms in which the principle may be used.
In the said drawings:
Figure I is a front elevation of the machine;
Figure II is a vertical section thereof, showing the spindles and rolls in side
elevation;
Figure III is a left-hand end elevation thereof;
Figure IV is a right-hand end elevation thereof;
Figure V is a horizontal section on the line 5-5 of Figure II;
Figure VI is an enlarged detail view of a central section on the line 6-6 of
Figure I, showing the feed rolls and compression rolls in elevation;
Figure VII is a detail section of one of the conducting roll stands, on the
line 77 of Figure II;
Figures VIII and IX are respectively a horizontal section, and a side elevation,
of a pair of compression rolls for taper tube work;
Figure X is a longitudinal central sectional view of one of the conducting rolls
and its spindle, and
Figure XI is a detail view of parts of one conducting roll and compression roll.
An electric transformer A is inclosed and supported in a suitable bed frame B,
upon the upper face of which slide horizontally two platens C C¹, Figure II. Each
of these platens is connected with the transformer, and is electrically insulated
from the said bed frame B by insulation pieces b, Figure VI; such insulated pieces
insulating the guide plates 61, which support and guide said platens, from the bed
frame. Screws c serve to move said platens toward and from each other.
Bolted respectively upon the platens C and C¹, are two stand frames D and D¹,
Figures I and II. In each of said frames is supported a journal box D², Figure II,
in which is arranged the spindle E, carrying at its inner extremity the current con-
ducting rolls E¹. The cap d, Figure VII, of said box fits between two lateral
flanges d', formed integral with the lower portion d² of the box. The said portion d²
slides snugly between the lateral faces of a shoe D³, and is formed with two lateral
T-grooves, in which are adapted to slide the heads of bolts d³, which extend through

page_text: the shoe, and project on the outside of the stand frames. A yoke d³ is bolted to
the top of the shoe D³; and has attached to it, a screw do, by which it may be
moved upwardly or downwardly.
Two lateral segments D are formed integral with the sides of the yoke; and
project into segmental slots D5, Figures I and II, formed in the frame. The centres
from which the segments are struck lie approximately in the axis of the tube
which is being welded; so that, by shifting the position of the segments, and hence
the spindles, the conducting rolls may be adjusted to accommodate different sizes
of tubes; all points in the said rolls moving, on such adjustment, in the arcs of
circles whose centres are the axis of the tube. The bolts d' are provided with
washers of larger diameter than the width of the slot; whereby the shoes may be
firmly bolted in their required positions.
Each conducting roll E is formed of a disc of pure copper, bolted or secured to
a flange e formed upon the end of spindle E see Figure X and has a concave work-
ing face which bears directly upon each side of the longitudinal joint. The vertical
plane passing through the axes of the conducting rolls, is before the vertical plane
passing through the axes of the compression rolls F and F; such two planes being
parallel with each other, and at right angles to the line of the tube movement.
Figure XI is a detail view on an enlarged scale, showing parts of one conducting
roll and one compression roll; the dotted line - marking the axial plane of
such conducting roll, and the dotted line y-y marking the axial plane of the com-
pression roll. I prefer to have the axial plane of the conducting rolls, from one
eighth to one quarter of an inch before the axial plane of the compression rolls.
In their operative positions, the two conducting rolls are, to an equal extent,
inclined to a plane determined by the longitudinal tube joint and the axis of the
tube. This inclined position of the current conducting roll results in a sufficient
pressure on the tube to insure the perfect contact of the free edges of the joint that
is to be welded, without bending or indenting the tube at the points of contact ;
that is, such force which causes such free edges to approach each other, is exerted
in a direction as nearly tangential to the curve of the tube, and hence as nearly
parallel with the material at such points of contact, as is practicable.
On the opposite faces of the stand frames D and D', are bolted, and electrically
insulated from said frame by insulation pieces g, Figure II, two bearings f and f¹;
such bearings carrying respectively, spindles 2 and 3, which are provided at their
upper extremities with the compression rolls and F. Roll F is driven by a
bevel gear G, secured to driving shaft G¹, and meshing with bevel gear G2 secured
to spindle such spindle having secured to it, spur gear G³, which latter meshes
with spur gear G+ secured to spindle f3. Each of said compression rolls is formed
upon its periphery with a concave face, adapted to receive and partially inclose a
tube. These two compression rolls F and F may be of any suitable size, to corre-
spond with the different sizes of tubing to be welded; they being connected with
their respective spindles. These two compression rolls, as well as the two conduct-
ing rolls, operate to make a definite and material up-set on each of the two meeting
edge portions of the tube; the construction and adaptation of all parts being such
as to insure such upsetting formation to a substantial degree.
Bolted upon the face of the stand frame D, is a frame H, Figures I, III, IV
and VI; such frame being electrically insulated from said stand frame, by insulation
pieces g. On the opposite side of said stand frame, is bolted, and electrically
insulated, a second frame H¹. The electric current, in its passage between
its opposite electric poles, must pass entirely and exclusively by way of the two
current conducting rolls; the construction and insulation of all machine parts
excluding other ways of passage.
The two frames, H and H¹, form bearings for two sets of draft roll spindles j j
and j, Figures I, IV and VI; such spindles carrying on their inner extremities,
the two sets of draft rolls J and J', Figure VI; such draft roll sets being respectively
on each side, in the line of the tube movement of the compression rolls F and Fi

page_text: The said spindles are driven by a train of gears K, which drive the upper draft
rolls in one direction, and the lower rolls in the opposite direction; said directions
being such as to move the tube forward,-such direction of movement being shown
as from right to left, in Figure VI. The said draft roll spindles are journalled in
boxes which slide in slots h, and whose position, with the exception, as hereinafter
shown, of the upper one of the pair of rolls J¹, is regulated and fixed by screws h¹.
Beneath the box forming the bearing for the spindle of the upper one of the pair
of rolls J¹, is a helical spring h2; such spring bearing against the lower face of said
box, and tending to push the latter up. A rod ³, bearing against the upper
face of said box, projects above the upper edge of the frame H; where it engages
with a cam h, formed upon a lever journalled on the upper face of the frame.
Thus, the upper roll may be retracted; and the two rolls be quickly stopped, or
started, as desired.
The distance between the two pairs of draft rolls should be less than the length
of the tube; so that, during compression, one or the other of the sets of draft rolls
engages the tube; ensuring an unvarying draft upon the tube, as a result of which
every point along the joint is subjected to the same amount of heat and pressure,
thereby making a homogeneous weld throughout the length of such joint.
On each side of the initial draft rolls J¹, and in the line of the tube movement
are respectively located, suitably secured to the stand H, two tube joint guides L
and L, Figure VI; guide L' directing the tube into the draft rolls J¹, and guide L
directing it into the compression rolls. An initial guide, initial draft-rolls, a second
guide, current conducting rolls, compression rolls, and a final set of draft rolls
being located in relative succession in the direction of the tube movement, and
performing their respective functions, one after the other, in order of time.
Pressure rollers M and M¹, located, respectively, before and after the set of final
draft rolls, are adapted to bear down upon the tube, and maintain it in horizontal
line at such points.
For welding taper tubes, I employ a special set of compression rolls, N; shown in
Figures VIII and IX; the groove n of such rolls being of spiral form, gradually
decreasing from the greatest to the least diameter of the tube.
In operating the machine, the tube is fed into the feed rolls J¹; the initial
guide L¹ directing it; the said rolls having been previously adjusted, to exert the
required amount of draft. After passing through said rolls, the tube, directed by
the second guide L, is received by the conducting rolls; the latter being adjusted
to compress the tube sufficiently to bring the contiguous free edges of the joint
into contact whereupon, the electric current passes across the joint, and heats the
metal on opposite sides thereof to a welding heat. The tube is then received by
the compression rolls, which completely compresses the parts together, and finishes
the weld. The tube is thereafter received by the final set of draft rolls, which
effects the proper delivery thereof.
Other modes of applying the principle of my invention may be employed, instead
of the one explained; change being made as regards the mechanism herein dis-
closed, provided the means covered by any one of the following claims be employed.
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:
1. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
and adapted to have contact respectively wth opposite edge portions of the joint
to be welded, of two rolls which receive between them the metal parts having said
edge portions, and press the latter together, substantially as set forth.
2. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
and adapted to press respectively against opposite edge portions of the joint to be
welded, of two rolls adapted to compress between them the metal parts having said

page_text: edge portions, said conducting devices also tending by their said pressure to force
said edge portions together, substantially as set forth.
3. The combination with two electric current conducting devices, electrically dis-
connected from each other, respectively connected with opposite electric poles, and
adapted to have contact respectively with opposite edge portions of the joint to be
welded, of two rolls, electrically disconnected from said conducting devices, and
adapted to compress between them the metal parts having said edge portions,
substantially as set forth.
4. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
and adapted to have contact respectively with opposite edge portions of the joint
to be welded, of two compression rolls, electrically disconnected from said conduct-
ing devices, adapted to partially inclose the metal parts having said edge portions,
and located respectively to opposite sides of said conducting devices at points further
from the joint than are such conducting devices, substantially as set forth.
5. The combination with two electric current conducting rolls, electrically dis-
connected from each other, respectively connected with opposite electric poles, and
which bear respectively against opposite edge portions of the joint to be welded, of
two rolls which are electrically disconnected from said conducting rolls, and which
compress between them the metal parts having said edge portions, substantially
as set forth.
6. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
and adapted to be in contact respectively along opposite edge portions of the joint
to be welded, of two compression rolls which partially inclose between them the
metal parts having said edge portions, and a joint guide located before said com-
pression rolls in a plane passing between said current conducting devices, sub-
stantially as set forth.
7. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
and adapted to have contact respectively with opposite edge portions of the joint
to be welded, of means adapted to press together the metal parts having said edge
portions, said conducting devices having their initial transverse plane of contact
with said edge portions before the initial transverse plane of contact of said com-
pressing means with said edge portions, substantially as set forth.
8. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
and adapted to have contact respectively with opposite edge portions of the joint
to be welded, of means adapted to press together the metal parts having said edge
portions, said conducting devices having their transverse plane of greatest electrical
energy before the transverse plane of the greatest mechanical energy of said com-
pressing means, substantially as set forth."
9. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
and adapted to have contact respectively with opposite edge portions of the joint
to be welded, of means adapted to compress between them the metal parts having
said edge portions, said conducting devices having their point of closest approach
to each other located in a transverse plane before the transverse plane in which the
point of closest approach to each other of said compressing means is located, sub-
stantially as set forth.
10. The combination with two electric current conducting rolls, electrically dis-
connected from each other, respectively connected with opposite electric poles, and
adapted to have contact respectively with opposite edge portions of the joint to be
welded, of two rolls adapted to compress between them the metal parts having said
edge portions, the axial plane of said conducting rolls crossing the line of movement
of said metal parts before the axial plane of said compression rolls, substantially
as set forth.

page_text: 11. The combination with two electric current conducting devices, electricany
disconnected from each other, respectively connected with opposite electric poles,
and adapted to have contact respectively with opposite edge portions of the joint
to be welded, of two rolls adapted to compress between them the metal parts having
said edge portions, together with two sets of draft devices located, respectively,
one set before and the other set after said compression rolls, substantially as set
forth.
12. The combination with two electric current conducting devices, electrically
disconnected from each other, respectively connected with opposite electric poles,
adapted to have contact respectively with opposite edge portions of the joint to
be welded, of two rolls adapted to compress between them the metal parts having
said edge portions, two guides for said joint edges, a pair of draft rolls between
said guides, said draft rolls and guides being located before said compression rolls,
and a pair of draft rolls located after the latter, substantially as set forth.
13. The combination with tube compression rolls, of two electric current con-
ducting rolls, electrically disconnected from each other, respectively connected with
opposite electric poles, adapted to be in contact respectively with opposite edge
portions of the longitudinal tube joint, and inclined to the plane determined by
the tube joint and the tube axis, substantially as set forth.
14. The combination with tube compression rolls, of two electric current conducting
1olls, electrically disconnected from each other, respectively connected with opposite
electric poles, adapted to be in contact respectively with opposite edge portions of
the longitudinal tube joint, and adjustably inclined to the plane determined by the
tube joint and the tube axis, substantially as set forth.
15. The combination with tube compression means, of two electric current con-
ducting devices, electrically disconnected from each other, respectively connected
with opposite electric poles, adapted to be in contact respectively with opposite edge
portions of the longitudinal tube joint, inclined to the plane determined by the tube
joint and the tube axis, and located with their transverse plane of closest approach
to each other before the transverse plane of closest approach to each other of said
tube compression means, substantially as set forth.
16. The combination with two electric current conducting rolls, electrically dis-
connected from each other, respectively connected with opposite electric poles,
adapted to be in contact respectively with opposite edge portions of the joint to be
welded, and inclined to the plane determined by the tube joint and the tube axis,
of two rolls, electrically disconnected from said conducting rolls, and adapted to
compress the tube between them, said conducting rolls having their transverse
plane of closest approach to each other before the transverse plane of closest
approach to each other of said tube compression rolls, substantially as set forth.
Doted this 22nd day of September 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.