Improvement in the Manufacture of Rubber Tubing.
Year: 1897

page_text: Date of Application, 7th Dec., 1897-Accepted, 20th May, 1898
[Communicated from abroad by BERTRAM GEORGE WORK, Superintendent, of
Rubber Manufacture, Akron, County of Summit, State of Ohio, United States
of America.]
Improvement in the Manufacture of Rubber Tubing.
ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement: -
This invention relates to the manufacture of rubber tubing and more particu-
larly to a machine contrived for the manufacture of tubing out of calendered sheets
of rubber. Rubber tubing for use in the arts, either as the inner tube of bicycle
tires, hose, or the like, or for the various other uses to which rubber tubing as such
is put, as well as for use in manufacturing elastic bands and other articles of an
endless character, and relatively short in their transverse length, have hitherto
been made by a method employing a tubing machine constructed with a die and
plunger, or other feeding device, which serves to force out through an annular
aperture a seamless tube of any desired length and thickness of material; another
method of manufacture has been to form a sheet, usually by calendering, though
not necessarily so, this sheet being cut into strips of double the width of the
intended tube, and to bring the edges together and seal them, usually applying a
reinforcing strip over the meeting edges to give strength at this point. Doubtless
other methods of manufacture have been practiced, but these two have been the
most prominent. A well-recognized objection to tubing made on a machine
employing a forcing plunger and operating to produce a seamless tube in the first
instance is that the wall of rubber was necessarily irregular in its texture, and this
irregularity became more pronounced as the effect of vulcanization. For many
uses to which rubber tubing is put, therefore, this method of manufacture is
undesirable. The main objection that has heretofore presented itself to the rubber
tubing produced from a calendered or other flat strip has been that the manufacture
necessarily involves hand labor, which not only materially increases the cost, but
moreover limits the output; and a further objection is found in the fact that even
the utmost care which can be practiced in establishments employing the many
employees engaged on this class of work will not prevent irregularity in the joint
of the product. The edges being brought together by hand, abutted by hand,
pressed together by hand, rolled down by hand, and covered by hand with the rein-
forcing strip, many opportunities present themselves for the introduction of the
results of almost imperceptible carelessness or inaccuracy, with the effect that the
joint is irregular and the strength of the tube materially lessened. These objec-
tions have long been known in the art, but so far as I am aware no successful
means of removing them have been contrived. Mechanical appliances have been
suggested for supplanting hand labor in one or another of the various operations
of manufacturing tubing; but so far as I am aware none of these have served to

page_text: remove to a material and desirable extent the objections heretofore presented and
now existing.
The object of this invention is primarily to produce rubber tubing from sheets
by the employment throughout the operation of power driven machinery. A
further and subsidiary, or as it may be called an incidental object of this inven-
tion, is to produce a tube which notwithstanding that it is made from a sheet the
edges of which are caused to abut, shall, to all practical purposes, be seamless, this
being effected by the method and means employed for producing the joint in the
unvulcanized rubber, whereby at this point a strength in the rubber product will
be found substantially equal to that found in any other part of the product. A
further incidental object is to produce rubber tubing absolutely uniform through-
out, that is to say, exactly the same in cross-section at any one point as it is in
all others. Finally, a further object of this invention is to produce means for the
manufacture of rubber tubing more economically both in the matter of the actual
cost and in the matter of the saving in waste material than has been possible by
any method heretofore practiced.
To these ends this invention consists in the features hereinafter described and
pointed out in the claims.
In the drawings, in which because of the size of the apparatus, and with a view
to making clear the details of construction which enter therein, my correspondent
has illustrated the various sections of the apparatus on separate sheets and have
not illustrated them as all assembled on a single sheet,-
Figure 1 is a view in side elevation of the head-end of the machine, or that at
which the flat rubber strip is received and at which the strip is folded over into a
tube shape ready for the formation of the joint; Figure 2 is a plan view of the
head-end of the machine; Figure 3, a plan view of the guide-plate and cementing
apparatus which operates upon the folded strip before it leaves the head-end;
Figure 4, a side elevation of said guide-plate and cementing apparatus; Figure 5,
an end view of the same; Figure 6, a side elevation of the tail-end of the machine
showing the mechanism for forming and perfecting the joint and for cutting the
tube into sections; Figure 7, a plan view of the same; Figure 8, a plan view of the
rollers which operate upon the partially formed tube to complete the joint;
Figure 9, a view in side elevation of the same; Figure 10, a view in side elevation
of the shearing off mechanism for separating the tube into sections; Figure 11, a
view in vertical cross-section taken on the irregular line 11-11 of Figure 10 and
viewed in the direction of the arrow; Figure 12, a view in side elevation; and
Figure 13, a view in front sectional elevation of the mechanism employed when
required for applying to the tube a reinforcing strip over the joint.
It may be explained that the head-end and the tail-end of the apparatus are
separated by a distance sufficient to permit the solution upon the edges sufficiently
to dry in the time required to pass from the head-end to the tail-end of the machine.
This distance may be measured by the room afforded in the factory and may be
twenty-five feet and may be more or less. It may also be stated, however, that all
the machinery involved in the head-end and in the tail-end is driven from a common
source of power, it being important, though of course not essential, that the opera-
tions of the two ends of the mechanism shall be concurrent.
Extending from a frame or table A at the head-end of the machine to a frame
or table B at the tail-end of the machine is an endless belt C, having the centrally
arranged endless strip or pad C₁ thereon. The belt C passes around the roller t at
the extreme end of the table A, which roller is made adjustable with relation to
the frame or table by a screw t¹ passing through the hanger and bearing against
a stationary part of the table, as indicated in Figure 1 and said belt extends
from the roller t in a substantially horizontal plane to the roller ³, thence down-
ward around the roller #, thence upward over the roller and thence in a hori-
zontal plane to the tail-end of the machine, where it passes around the roller to and
downward around the roller 17, thence back to the head-end of the machine, where
it passes around the roller and upward to the roller t. The function of the belt C

page_text: is to carry the rubber, led thereto from a stock reel C³, to the various operative parts
of the mechanism for the formation of the rubber into a tube.
The rubber as received from the stock reel C2 is preferably in the form of a sheet
or strip slightly wider than the intended width of rubber in the tube. This strip
being led to the belt C and received between it and the pressure roller s is fed
forward and received by the first of the series of four (more or less) folding rollers s¹.
These folding rollers si are at one end outwardly beveled and may be all the same
length, although for reasons presently appearing, they are made gradually shorter
as they approach the guide-plate. Above the rollers s¹ is mounted the folding
plate D which is made of a sheet of tin or other suitable material, folded upon itself
in a wide fold and in such a manner that the folded edge shall gradually taper
toward the fixed edge. At its widest part the folder is adapted to receive the full
width of the strip, which strip in passing through the folder with the co-operation
of the rollers s', is folded, so that the edges are brought into substantially the same
line at the side of the folder, indicated by the letter & Figure 2. It should be stated
that the strip of rubber before being conveyed to the belt C has one surface thereof
covered with soap-stone flour, or other suitable agent, which will prevent the
cohesion of the meeting surfaces. From the folder and from and over the last
roller s the curved over strip is led to the guide-plate E. The guide-plate E is
upon a standard E. This table E¹ supports the driving gear for the various
moving parts connected with the head-end of the apparatus. The parts of this
driving gear are lettered E, E³, E, E³, E6, E7 and 8. E2 indicates any suitable
means transmitting to this mechanism the power from the primary source of power.
The large gear carries the pulley which gives motion to the belt C.
grears E and E8 co-operate to drive the strip shearing-rollers F F¹, the function of
which will presently appear.
The
The folded strip passes under the feeding rollers r which serve to guide it
in a straight line to and away from the co-operating circular shears FF, which
serve to cut from the meeting edges of the folded strip a strip y which is in turn
led to the roller y¹ (Figure 2), and thus away from the machine. The effect of
the shear cut is not merely to form a square edge on both members which consti-
tute the joint of the tube, but to bring the extreme inner corners of the edges into
close contact under heavy pressure, with the result that the tube is entirely closed
by this contact of the extreme inner corners of the edges. The folded strip being
fed onward passes the rotating brush G which is driven by gear connection in any
suitable manner with the chain of gear E² to E8 and dips in its rotation in a solu-
tion-tank G receiving solution through an automatic feed from the solution-
supply G2 through the pipe G³. The edge of the brush G operates squarely upon
the edges of the folded strip and applies to these edges a solution of rubber. This
operation is more clearly illustrated in Figure 5. The tube thus partly formed is
now again received upon the belt C and carried to the tail-end of the machine.
The edge of the folded strip lies upon the central web or pad C₁ upon the belt C
and is thereby raised out of contact with the belt and given every opportunity to
dry to the point necessary for the sufficient evaporation of the benzine which the
solution contains.
At the tail-end of the machine the tube, which is in an approximately flattened
condition, enters the deflector H which is in the form of a tube of an internal
dimension throughout slightly in excess of the dimension of the folded strip
which it receives and presents a gradual change in its exterior contour from the
horizontal presented opening at the admitting end to a vertically presented open-
ing at the other end. As the result of passing through the deflector H the tube
which had before presented its meeting edges at one side, now presents its meeting
edges on top. From the deflector H the tube passes between the vertical rollers I
and thence under the converging pressure rollers K. These rollers K are each on
a horizontal axis and are so arranged that at the side where they first receive the
tube they are separated, while at the opposite side they are practically in contact
with each other, as illustrated in Figure 8. These rollers K bear downward on the

page_text: tube in its passage from the rollers I to the rollers L, and serve by gentle pressure
on either side of the joint to cause the edges of the rubber strip to be brought
gradually toward each other, and in fact to come into intimate contact throughout
the surface of the edge before the line of meeting is under the pressing action of
the rollers L. At the moment that the tube passes the rollers K the joint is com-
pletely formed, but in order that absolute firminess may be assured it is now passed
between the rollers LL', the upper one of which by preference is centrally grooved,
while the lower, L', has an annular tongue entering this groove, and the pressure
afforded between the rollers thus presented serves firmly and finally to complete the
formation of the joint between the edges of the tube.
After the tube is thus formed it may at once be wound upon a reel, or in any
other suitable manner arranged for transportation or storage, or it may be cut off
into lengths by hand. It is preferable, however, to employ in connection with the
apparatus the shearing off arrangement which will automatically shear off the
lengths of tube as the same passes out from under the rollers L L'. This shearing
off arrangement is illustrated in Figures 6, 10 and 11.
Extending transversely across the bed of the carrier is a shear comprising the
two spring distended co-acting blades MM', which under the operation of the
mechanism presently shown has a scissors action. The tube is fed between
the blades M M which are distended by the spring M² during this time.
Supported upon one side of the frame upon the standard N is a hammer N¹
having at its outer end the recess p, in which, on a pivot p¹, is swung the nose p²
having a pin 23 which moves in the elongated slot 4. Between the inner wall of
the recess and the nose p² is a spring 7. A link o connects the hammer N¹
with a bent arm O pivoted at n in the vertical guide-standard 0¹. The free end of
the arm O carries the roller 03 which contacts with the cam P driven through the
medium of gear from the same source of power as all the rest of the apparatus.
The inner face of the guide-standard 01 affords a guide-surface which bears upon
the swinging nose 2 upon the hammer N¹, as the hammer descends in the manner
presently described, to cause the latter to be gradually forced inward. The
movable member M of the shear passes through the slot m extending transversely
through the guide-standard (1
The operation is as follows:
At the moment when the cam releases the roller 03 the hammer N¹ falls, the
nose strikes against the movable blade M, at a point near its extremity, and a
forces it downward effecting in conjunction with the stationary blade M' a rapid
shear cut across the tube. As the hammer continues to fall the nose p² is driven so
far into the recess that the movable blade M is free from contact with the nose
and therefore, under the action of its own spring Me, this member, M, is allowid
quickly to rise to release the tube and permit its immediate further advancement
under the operation of the feeding rollers, while the hammer N¹ rises more slowly
under the lifting action of the cam P.
It is found that owing to the perfect parallelism in the edges of the folded strip
coupled with the perfect joint of the corners of these edges, effected through the
operation of the shear cutting rollers F F, and the gradual but effective closing 4
pressure obtained through the operation of the rollers K and L L', the joint in the
tube is so perfectly made as in most instances to require no reinforcement. Indeed,
it is found that with tubing of a certain thickness of material the strength at the
joint is fully equal to that at any other part of the tube. For many reasons, how-
ever, and particularly where the tube is to be used as the inner tube of a pneumatic 5
tire, it is deemed desirable to reinforce this joint with a strip of rubber, and this
operation is accomplished during the movement of the tube through the machine
by the apparatus illustrated in Figures 12 and 13. It comprises a frame which
supports at one of its upper opposite corners a stock reel Q, on which is wound a
strip of rubber laid between strips of paper, linen or other material, which will
prevent the adjacent tolds from adhering one to the other; while the other upper
corner of the frame receives the reel Q, the purpose of which is to receive the

page_text: paper, or other protective strip, and withdraw it from the rubber. These reels are
driven in unison by free disks 11, the former of which bears upon the hub of the
reel Qand the paper on the reel Q, while the latter bears upon the stock on the
reel Qand the hub of the reel Q2. Centrally upon the upper cross piece of
the frame is a guide-roller 22, which serves to guide the paper or other reinforcing
strip to the reel Q2, and adjacent thereto, and preferably supported upon the
hanger, is a guide-roller k over which the rubber-strip R is led downward to the
guide-tube . The driving power for rotating the reels and feeding the strip, and
for operating the mechanism, which applies the strip to the tube, is found in the
gears S, S1, S2, S3, S4, S5 and 8%. Each of these gears, S, S1, S2, S3 and S+, carries
a roller and the tube to which the strip is applied passes between the rollers on the
gears SS, which if preferred may correspond with the rollers LL, and from
between the rollers it passes under the roller on the gear S2, and between
rollers T T driven, respectively by the gears S¹ S³. As the tube passes between
the rollers T T it receives the strip E fed thereto through the guide-tube, and the
rollers TT serve to press the strip with great power upon the tube over the joint
thereof, producing perfect and uniform adhesion of this strip at this point. The
tube with the strip applied is then led under the roller T2 and thus to the shearing
off mechanism, if the latter is used.
For the purpose of securing uniformity in movement between the head-end and
the tail-end of the machine, which being separated a long way from each other are
liable to vary in their speed, my correspondent employs in connection with the
driving belts, which drive the tail-end of the machine the cone-pulleys U, U¹, U³
and U, the pair U U being connected by a belt, and the pair U2 U3 being con-
nected by a belt. Of these the pair are connected with and operate the tube
joint forming mechanism which can therefore have an increased or decreased speed
of movement by simply shifting the belt transversely upon the oppositely arranged
cone-pulleys UU. The cone-pulleys U³ ³ are associated with the operation of
the shearing off mechanism, which may thus obviously be caused to be operated
with greater or less speed by simply shifting the belt along these pulleys.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent I declare that what I
claim is:-
1. In the manufacture of rubber tubing from sheets, the means for forming the
joint without increasing the thickness of the tube which comprises, in combina-
tion, means for folding the sheet, means for shearing the meeting edges and
simultaneously pressing said edges together to cause their union at the extreme
corner, means for deflecting the joined edges toward the medium longitudinal
line of the flattened tube, and means for exerting upon the tube at the joined edges
pressure whereby the joint may be perfected, substantially as described.
2. In a machine for making rubber tubing from sheets cut into strips, the com-
bination with a folder, of a shear cutter, a deflector, whereby the meeting edges are
brought to a median line in the flattened tube, and pressers, whereby the meeting
edges are brought together, substantially as described.
3. In a machine for making tubing from sheets cut into strips, the combination
with the folder, of a shear cutter operating to shear off the meeting edges and join
the inner corners of said edges under pressure, a solution applying device operating
to solution said edges, and rollers operating upon the tube to force said edges
together and perfect the joint the parts being arranged as set forth, whereby the
solution may be permitted to dry before said edges are pressed together, substan-
tially as described.
4. In a machine for making tubing from rubber strips, the combination of
folding, shearing and solutioning mechanisms, and joint forming and completing
mechanisms, said mechanisms being driven simultaneously, and a carrier operating
to convey the partially formed tube from the first series of mechanisms to the latter
series and serving to permit the solution to dry, substantially as described.

page_text: 5. In a machine for making tubing from rubber strips, the combination with a
carrier for the tube in process of manufacture, of tube forming, shearing and
solutioning mechanisms at one end of the carrier, and joint forming and com-
pleting mechanisms at the other end of the carrier, all driven simultaneously, sub-
stantially as described.
6. In a machine for forming tubes from rubber strips, the combination with the
carrier and means for folding the strip, of co-acting shear cutting discs FF¹,
operating to cut the strip off both edges of the sheet to leave a tube of the intended
dimension and at the same time to join together the opposite corners of said sheet
substantially as described.
7. In a machine for making tubes from rubber strips, the combination with
means for advancing the strip and with means for folding it into tubular form, of
rotary shear cutters FF, and guide-rollers co-operating with the shear cutters to
guide the folded strips through and away from said shear cutters, substantially
as described.
8. In a machine for forming tubes from rubber strips the combination with
means for advancing the strip and for folding the same and of means for cutting
the edge of the strip to produce a tube of the intended dimension, of a rotary solu-
tion brush engaging the cut edges of the strip and guides for conveying said
folded strip to and away from the solution brush, substantially as described.
9. In a machine for forming tubes from rubber strips, the combination with the
folding device for folding the strip into a tubular form, a cutting device for cutting
off the edges of the strip, and a solutioning device for solutioning said edges, of a
conveyer for conveying the folded and solutioned strip away from the solutioning
device to permit the solution thereon to dry, substantially as described.
10. In a machine for forming tubes from rubber strips, the combination with a
strip folder, and edge cutting means and a solutioning device, and with a carrier
to convey the strip away from said solutioning device and permit the solution
thereon to dry, of a deflector operating to twist the partially formed tube to change
the joint therein from the side toward a median line, and means for closing the
joint, substantially as described.
11. In a machine for forming tubes from rubber strips, the combination with
means for partially forming the tube into a folded strip with its edges adjusted
and solutioned, and with means for deflecting the partially formed tube whereby
it shall become twisted to present the joined edges at the middle thereof, of con-
verging rollers engaging the tube on opposite sides of the joint and operating to
press the meeting edges of the joint together, substantially as described.
12. In a machine for making tubes from rubber strips, the combination with
means for folding the strip, cutting off and adjusting the meeting edges and solu-
tioning said edges, of a deflector operating to bring the meeting edges to the longi-
tudinal centre of the tube, converging rollers engaging the tube on both sides of
said edges and operating to form the joint, and pressure rollers operating to com-
plete the joint by pressure thereon substantially as described.
13. In a machine for making tubes from rubber strips the combination with fold-
ing mechanism, edge cutting mechanism, and joint forming mechanism, of means
substantially as described, for applying to the tube in the course of manufacture,
and after the formation of the joint, a reinforcing strip substantially as set forth.
14. In a machine for forming tubing from rubber sheets, the combination with
the conveying belt, of the folder D, shear cutters F F¹, solutioner G, deflector H,
vertical rollers I, converging rollers K and compression rollers LL¹ substantially
as and for the purpose described.
15. In a machine for forming tubing from rubber sheets, the combination with
the carrier C, of the strip folding mechanism, shear cutters F F¹ operating to shear
the strip y from the tube and to join the inner corners of the meeting edges of the
tube, guides r r rotary solutioning brush G, deflector H, converging rollers K
and cam actuated spring controlled transversely arranged shears M M' substantially
as described,

page_text: 16. In a machine for forming tubing from rubber strips, the means for complet-
ing the joint of the opposite edges, comprising the vertical rollers I, and converging
rollers K, arranged to operate substantially as described.
17. In a machine for forming tubing from rubber strips, the means for severing
off lengths of tubing, comprising in combination, the transverse spring-controlled
shearing knives M M, the hammer N¹, operative to force the cutting knives towards
each other, and a rotary cam connected with and operating said hammer substan-
tially as described.
18. In a machine for forming rubber tubing, the means for cutting the tube into
lengths, comprising the transverse co-acting spring-controlled knives M M¹ the
hammer N having the swinging nose-piece the guide-standard O', the rotary
cam P and a connection between the cam and the hammer for actuating the latter,
the parts being arranged to operate substantially as described.
Dated this 7th day of December 1837.
BOULT & WADE,
Agents for the Applicant.