Improvements in the Manufacture of Air Cushion Tubes.
Year: 1898

page_text: Date of Application, 5th Mar., 1898-Accepted, 14th May, 1898
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Air Cushion Tubes.
I, HENRY JAMES DOUGHTY, of No. 680, Broad Street, in the City of Providence,
County of Providence, and State of Rhode Island, United States of America, Manu-
facturer, 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 to certain new and useful improvements in the method and
apparatus for the manufacture of air cushion tubes adapted for use in connection.
with bicycle tires and other articles; and it is the object of the invention to pro-
vide means whereby such tubes may be rapidly, economically and effectually formed.
With this object in view the invention consists in the method and the improved
apparatus for carrying out the same hereinafter more particularly described.
In the acompanying drawings forming a part of this specification, and in which
like letters of reference indicate corresponding parts:
Fig. 1 is a side elevation of the vulcanizing press with the tube mold therein;
Fig. 2 is an end view of the same;
Fig. 3 is an enlarged detail sectional side elevation of one end of the tube mold;
Fig. 4 is a transverse sectional view of the same;
Fig. 5 is a similar plan view of the lower half thereof;
Fig. 6 is a detail plan view of the auxiliary mold, the sections thereof being
separated and broken away;
Fig. 7 is a side view of one of the auxiliary mold sections;
Fig. 8 is a detail view of one of the inflation tube mandrels;
Fig. 9 is a similar view of the same with an inflation tube thereon; and
Figs. 10 to 14 are diagrammatic views illustrating the operation and features of
the improved method and apparatus.
Referring to the drawings, and more particularly to Figs. 1 to 8 thereof, A,
designates a vulcanizing press and mold comprising a base 1, an upper mold
section c, connected with a casing provided with a heating chamber, and sup-
ported upon uprights 4, extending from the base 1. A lower mold section d, is
guided to move upon the uprights 4, towards and from the upper section, and
while different means may be employed for moving the lower mold section, it is
preferred to employ one or more engines C, each comprising a cylinder 6, connected
to the under face of the mold section d, and in which is a suitably packed piston 7,
provided with a passage 8, extending through it to the upper face thereof and
communicating with a supply pipe 9, through which water or other fluid under
pressure is introduced into the passage 8, and from thence into the cylinder.
The lower mold section d, like the upper one is also connected with a casing c
provided with a heating chamber, and pipes 10, 12, communicate with the chambers
of the upper and lower sections respectively through which steam, hot water or
other heating fluid is supplied to the said chambers. In order, however, to com-
pensate for the movement of the lower mold section, a sliding joint is provided
at 14, which permits the section to move upon the pipe as it is raised and lowered.
The mold and press A, as hereinbefore stated, is preferably formed in two

page_text: sections c and d, the opposing faces of which are flat and are each provided with
longitudinal semicircular or substantially semicircular channels e, which register
when. the sections of the mold are brought together to form circular chambers
which at their opposite ends are slightly less in diameter than at intermediate
points, and these contracted portions constitute bearings do, the purpose of which
will presently appear.
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In carrying out the invention two or more mandrels are arranged parallel to each
other between two sheets of vulcanizable' material, which sheets are brought
together intermediate and at the sides of the mandrels so as to be carried with the
mandrels to the vulcanizing press and mold: "These operations may be performed
in different ways and with different devices, and instead of using two sheets of
material, a single sheet may be laid flat and the sheet then turned over the
mandrels and pressed together at the edges, forming upper and lower inclosing
layers as shown in Fig. 14; or instead of this the lower layer 2, of the material is
placed upon a channeled tray 2, Fig. 10; the mandrels a, a, are placed upon the
sheet and press the same into the channels of the tray; another layer or sheet,
is then laid upon the mandrels and another channeled tray 3, is placed on the first,
pressing the sheets closely around the mandrels and together at the sides and
between the mandrels. Whatever may be the means adopted of assembling the
mandrels and the vulcanizable sheets, it is requisite to maintain them in position
in transferring them to the vulcanizing press. This may be accomplished by means
of two socket bars b, Fig. 11, one of which is placed beneath the ends of the mandrels
projecting beyond the trays or beyond the sheets, at each end of the
mandrels, and the latter with the adhering sheets are then lifted from the lower
tray after first removing the upper one by means of the socket bars and carried to
and placed in the lower mold section d, the mandrels entering the longitudinal
recesses e, of said mold section, with their ends fitting closely the contracted ends
or bearings of the recesses. When this has been accomplished the racks b, are
removed and the upper and lower mold sections c, d, are brought together and
maintained in contact until the material has been sufficiently vulcanized upon
the mandrels. The mandrels with the tubes thereon connected by narrow thin
webs or films ³, are then removed from the press and the said webs are severed,
the tubes then being stripped from the mandrels ready for use.
The tubes used in bicycle tires are provided each with a short air tube 4, of small
diameter protruding from the side of and communicating with the interior of the
main tube through which air is forced into the main tube to inflate the same.
When the tubes are to be employed for this purpose it is desirable that the air tubes
be joined to the main tubes simultaneously with the formation and vulcanization
thereof. Accordingly the lower mold section d has in its face a transverse recess
into which is received an auxiliary mold B, having two parts provided in their
opposing faces with a series of semi-circular recesses f, which coincide and con-
form to the shape of the air tubes when the two parts of the mold are brought
together. At their opposite ends the parts of the mold B, are provided with handles
by means of which the mold may be lifted into and out of the recess of the lower
mold section d, and in its upper face the mold B, is provided with semicircular
channels 9, which register with the longitudinal recesses of the said mold section d,
see Fig. 5. The openings of the mold B, lead from the channels g, and formed in
said. channels and surrounding the openings are shallow recesses h. Prior to
placing the mandrels a, and the strips x, x², in the mold section d, inflation tubes a*,
of green rubber and fabric provided at one end with an annular flange are slipped
upon short mandrels i, Fig. 9 and inserted into the openings of the mold B, with
their flanges within the recesses h. The mold B, is then placed within the trans-
verse recess of the lower mold section d, after which the mandrels and strips x, a³,
are placed upon the mold section d, as above described and the flanges of the
inflation tubes are vulcanized to the main tubes X, simultaneously with the forma-
tion and vulcanization thereof.
4

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1st. The herein before described method of making air cushion tubes, the same
consisting in enveloping two or more separated mandrels in sheet rubber, then by
pressure molding and vulcanizing the rubber around the mandrels, and finally
removing the connecting webs intermediate the mandrels, substantially as
described.
2nd. In an apparatus for the purpose described, the combination of a sectional
mold having circular chambers with contracted ends, and mandrels adapted to be
received in said ends and to project beyond the same, said mandrels extending
centrally through the said circular chambers, substantially as described.
3rd. In an apparatus for the purpose described, the combination with a main
sectional mold, of an auxiliary mold adapted to be attached to and detached from
one of the sections of the main mold and to communicate with the chamber thereof,
substantially as described.
4th. In an apparatus for the purpose described, the combination of a mold
formed in two sections having longitudinal circular chambers and mandrels extend-
ing centrally through the chambers and supported in bearings at the ends of the
same, substantially as described.
5th. In an apparatus for the purpose described, the combination with a sectional
mold having longitudinal open ended chambers, of two or more mandrels extending
centrally through the chambers and to project beyond the same. and racks at the
ends of the mandrels for maintaining them in proper relative position, substantially
as described.
6th. In an apparatus for the purpose described, the combination with a vul-
canizing mold, of an auxiliary mold adapted to be attached to and detached from
the said mold and having an air tube opening communicating with the chamber
thereof, substantially as described.
7th. In an apparatus for the purpose described, the combination with a vul-
canizing mold having a transverse recess intersecting the chamber thereof, and an
auxiliary two part mold adapted to be received in said recess and having air tube
openings communicating with the chamber of the vulcanizing mold, substantially
as described.
Dated the 5th day of March A.D. 1898.
BOULT & WADE,
Agents for the Applicant.