Improvements in or relating to the Manufacture of Rubber Hose.
Year: 1897

page_text: Date of Application, 3rd Aug., 1897-Accepted, 4th Sept., 1897
Improvements in or relating to the Manufacture of Rubber Hose.
A communication from HENRY BOSWELL COBB, of Wilmington, County of New.
Castle, State of Delaware, United States of America, Manufacturer, and
EDWARD THOMAS DAVIS, corner 9th and Parrish Streets, Philadelphia, State
of Pennsylvania, United States of America, Agent.
I, 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:-
A usual method, heretofore practiced, of manufacturing rubber hose, of the
different kinds adapted for the various purposes to which this article is commonly
applied, consists in building it up, on a mandrel, of layers of unvulcanized sheet-
rubber and canvas or other suitable fabric, and vulcanizing the whole to properly
cure the rubber and cement the different layers together.
The article thus produced is manufactured, in the main, at least, by hand,
involving a slow and comparatively expensive procedure, the result of which is
hose which is not satisfactorily durable, since it quickly wears out with ordinary
usage; and when such hose has once started to wear, as by a hole being worn
through or partly through it, fluid forced through it tends to separate the layers
from each other by forcing itself between them and thus soon destroys the useful-
ness of the hose. Moreover the length in which hose, so manufactured, can be
provided is limited by the length of mandrel employed in its manufacture, which,
by reason of its unwieldiness, rarely is longer than from, say, fifty to sixty feet.
This invention relates to an improvement in the manufacture of rubber hose;
and the object is to provide a novel method of manufacture, wherein all the steps
are performed by machinery for producing an article of rubber hose which shall
be exceptionally durable and so elastic that any kink or bend in it will automati-
cally straighten itself out, the method permitting the article to be manufactured
in very great continuous lengths, thus in hundreds of feet, in which to furnish it
to dealers, who may thus cut off and supply therefrom, to their customers any
lengths they may desire, which could not be done with the ordinary hose-lengths
hitherto provided to dealers without rendering the remainder more or less unsalable.
To practice the improved method there is first formed of rubber, which is
unvulcanized, but prepared for vulcanization, a tube in any desired length, say
five hundred feet or more. This may readily be done by the use of a well-known
rubber-tube forming machine in which the prepared rubber stock is fed to dies,
from which it emerges as tubing and is received and coiled upon a suitable.
holder. Upon this rubber tubing is provided a fabric-covering of fibrous material,
as hemp or similar cord, or of metal strips or ribbon, braided or woven, but
preferably braided in open-work about the exterior surface of the tubing, which,
in its covered condition, is again coiled upon a suitable reel as it emerges from
the braiding machine. There is then applied about this covered tubing a cover-
ing of rubber prepared for vulcanization and preferably in the form of sheet-

page_text: rubber; and the product thus formed is thereupon passed through a lead-press,
whereby it is encased in a sheath of lead. In fact it is the preferred practice
to apply the sheet-rubber covering to the fabric-covered rubber tubing as it is
being fed lengthwise through the lead-press, since thereby the edges of the sheet-
rubber, which should be just wide enough to form the envelope with its edges
meeting, are united, with an imperceptible junction, by the heat in the press.
It is also desirable, by way of preventing the fabric-covered tubing from collapsing,
in passing through the lead-press, to maintain within it an adequate pressure of
air, or other suitable fluid expansible under the influence of heat, as it is the
practice to do, for the effect of the counter-pressure of the fluid in forcing the
substance of the confined layers of rubber between the interstices of the fabric
and thus uniting the whole into an integral.mass..
As the lead-covered product emerges from the lead-press it should be coiled
about a metal reel; and it is then subjected to vulcanization according to any
suitable process, preferably that involving the confinement of the reeled lead-
covered article in a steam vulcanizing oven, with air, or other suitable fluid, at
high pressure (say 50 pounds to the square inch) confined inside the tubing,
whereby the vulcanizing heat in the oven greatly expands the fluid, which accord-
ingly subjects the rubber and interposed fabric of the tubing to great pressure
against the resistance of the lead sheath, and firmly united, through the interstices
of the fabric the separate rubber portions of the hose and incorporating therein
the fabric. Thus the different parts of the hose are united in a single body
composed of inseparable, mutually-incorporating parts, whereby the article is
rendered very strong and durable.
As will be understood, any desired number of alternate layers of rubber and
fabric may be employed, depending upon the size and character of hose to be
produced.
After the vulcanizing treatment has been completed, the lead-covered coil is
removed from the vulcanizing medium, and, after the confined air has been
released, (as by cutting off an end of the coiled article) the lead covering is taken
off. A convenient way of removing the lead sheath is to run the article length-
wise through a well-known stripping machine; and from this machine the
finished hose may be wound upon a reel, ready for storage or shipment.
The accompanying drawings illustrate the improved method by showing the
article in the successive stages of its production. Thus Figure 1 is a diagram-
matic view in elevation showing the rubber tubing A, a portion of the tubing
surrounded by an open-work fabric covering B of braided fibrous material, a
portion of the braid-covered tubing covered with sheet-rubber C, the view indicat-
ing the manner of applying to the fabric-covered tubing the sheet-rubber covering,
and a portion of the sheet-rubber covering on the article after it has passed
through a lead-press and received its covering 1) of lead; Figure 2 is a cross-
section of the completed article of hose after its vulcanization in the lead sheath,.
which has thereupon been stripped off; Figure 3, an enlarged view of a section
of the braided covering of fibreus material showing the mesh exaggerated to present.
its open-work character more clearly than in Figure 1; and Figure 4 is a similar.
view of a modification, showing the braid denoted B', as formed of ribbon or very
thin strips of sheet-metal.
In addition to its purpose as hose, the product of the improved method is
intended for use in bicycle and other vehicle tires, to adapt it for which purpose
the braided metal covering B¹ is more especially provided; and to make tires out
of the hose, it need but be cut into proper lengths, which, when their ends are
joined together, and after they have been equipped with suitable, air-valves, if
desired, may be applied to the rims of the wheels adapted to receive them.
As will be seen from the foregoing specification the invention consists, broadly
in forming about a tube of alternate layers of rubber and fabric an. inelastic
mold, and maintaining within the tube during the molding operation a counter-
pressure of expansible fluid. Also in subjecting the mold-covered product to

page_text: vulcanization and finally removing the mold. These latter steps being also taken
while the counter-pressure of expansible fluid continues within the tube. In the
vulcanization the mold covered product is subjected to heat, which causes the
expansion of the fluid within the tubing and tends to expand the latter; but this
is resisted by the inelastic mold with the result that the layers of rubber are
forced together into intimate union through the interstices of the fabric; the
presence of the internal pressure within the tube during the molding operation
and also of the pressure exerted externally by the mold itself, has the tendency
to exclude from between the tube and the mold all air which would ordinarily
be confined therein, the result being the avoidance of any inequalities in the
surface of the finished product.
Having now particularly described & ascertained the nature of the said in-
vention & in what manner the same is to be performed as communicated to
me by my foreign correspondent, I declare that what I claim is :-
1. The method of manufacturing rubber hose, which consists in forming about
a tube of alternate layers of rubber and fabric an inelastic mold and maintaining
inside the tubing a counter-pressure of expansible fluid during the molding opera-
tion, then subjecting the mold-covered product to vulcanization and finally
removing the mold.
2. The method of manufacturing rubber hose, which consists in molding about
a tube of alternate layers of rubber and fabric a covering of lead and maintaining
inside the tubing a counter-pressure of expansible fluid during the molding
operation, then subjecting the lead-covered product to vulcanization and finally
removing the lead covering.
3. The method of manufacturing rubber hose, which consists in forming about
a tube of alternate layers of rubber and fabric an inclastic mold and maintaining
inside the tubing a counter-pressure of expansible fluid during the molding
operation, then subjecting the mold-covered product to heat and finally removing
the mold.
4. The method of manufacturing rubber hose, which consists in molding about
a tube of alternate layers of rubber and fabric a covering of lead and maintaining
inside the tubing a counter-pressure of expansible fluid during the molding
operation, then subjecting the lead-covered product to heat and finally removing
the lead covering.
5. The method of manufacturing rubber hose, which consists in making rubber
tubing by forcing rubber, prepared for vulcanization, through tube-forming dies,
forming about said tubing an open-work covering, then encasing said covered
tubing in unvulcanized rubber, forming about the whole an inelastic mold, and
maintaining inside the tubing, during the molding operation, a counter-pressure
of expansible fluid, then subjecting the mold-covered product to vulcanization and
finally removing the mold, substantially as described.
6. The method of manufacturing rubber hose, which consists in making rubber
tubing by forcing rubber, prepared for vulcanization, through tube-forming dies,
forming about said tubing an open-work covering and covering it with sheet-
rubber, then molding about the whole a covering of lead, and maintaining inside
the tubing, during the molding operation, a counter-pressure of expansible fluid,
subjecting the lead-covered product to vulcanization and finally removing the
lead-covering, substantially as described.
7. The method of manufacturing rubber hose, which consists in forming about
unvulcanized rubber tubing an open-work covering, then encasing said covered
tubing in unvulcanized rubber, molding about the whole a covering of lead and
maintaining inside the tubing a counter-pressure of expansible fluid during the
molding operation, then subjecting the lead-covered product to vulcanization and
finally removing the lead covering, substantially as described.
8. In the manufacture of rubber hose composed of alternate layers of rubber
and fabric, the method of forming a tubular layer of the rubber, which consists

page_text: in passing sheet-rubber through a former and uniting the edges of the rubber
sheet by heat, while so forming it into tubing.
9. A step in the art of manufacturing rubber hose which consists in forming
about a tube of alternate layers of rubber and fabric an inelastic mold, and
maintaining during the molding operation a counter-pressure of expansible fluid.
Dated this 3rd August 1897.
BOULT & WADE,
Agents for the Applicant.