Improved Method and Means for Embossing or similarly Shaping Sheet Rubber Tubing.
Year: 1896

page_text: Date of Application, 2nd May, 1896
Complete Specification Left, 2nd Feb., 1897-Accepted, 1st May, 1897
PROVISIONAL
PECIFIO
Improved Method and Means for Embossing or similarly Shaping
Sheet Rubber Tubing.
1, WILLIAM GLASS WRENCH, of 27 Oswald Street, Glasgow, in the County
of Lanark, Consulting Engineer, do hereby declare the nature of this invention to
be as follows:-
The object of this invention is to cheapen and simplify the method of e.nbossing
or impressing the surface of sheet rubber or other material into any desired figure
or pattern whether as a depression thereon or in relief, and is intended to be
particularly applicable to the manufacture of the inner or air tabes of pneumatic
wheel tyres having corrugated or pocket like depressions or protuberances
thereon.
To this end I propose to lay the thin sheet rubber in its plastic or unvulcanised
state over the forming mandrel or other shaping surface in the usual way and
thereafter to surround same with an outer casing into which air or other fluid
medium can be pumped until such pressure is acquired as will by acting on the
external surface of the rubber force it into whatever depressions there are upon
the surface of the mandrel or cause it to assume the contour of the shaping surface.
Provision is or may be made by means of small air holes for the escape of air or
other resisting pressure therefrom into the interior or atmosphere side of the
mandrel which for this purpose is preferably made hollow. This process is intended
to obviate the use of a double moulding tube or plate..
Mar 1806
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicant.
Improved Method and Means for Embossing or similarly Shaping
Sheet Rubber Tubing.
I, WILLIAM GLASS WRENCH, of 27 Oswald Street, Glasgow, in the County
of Lanark, Consulting 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 this invention is to cheapen and simplify the method of embossing
or impressing the surface of sheet rubber or other like plastic material into any
desired figure or pattern whether as a depression thereon or in relief, and is
intended to be particularly applicable to the manufacture of the inner or air tubes
of pneumatic wheel tyres and which tubes have corrugated or pocket like depressions
or protuberances thereon.

page_text: In the accompanying drawings which illustrate the manner of carrying out my
invention,
Figure 1 is a cross section and Figure 2 a longitudinal section of part of a
forming mandrel such as I employ in the process of embossing or impressing the
surface of a rubber air tube and
Figure 3 is an elevation showing a portion of an air tube as fitted over the
forming mandrel during the impressing process.
As indicated by these drawings, I lay the thin sheet rubber A in its semi-cured
plastic or unvulcanised state over the forming mandrel B or other shaping surface
in the usual way and thereafter surround.same with an outer casing into which air
steam or other fluid medium can be pumped or otherwise admitted until such
pressure is acquired as will by acting immediately upon the external surface of the
rubber A, force it into whatever depressions such as 6 there are upon the surface
of the mandrel or cause it to assume the contour of the shaping surface B before
it gets time to soften or become otherwise too much affected by temperature which
latter must, for the success of this process be preceded by pressure. Provision is
or may be made by means of one or more small air holes C for the escape of air
or. other resisting pressure, therefrom into the interior or atmospheric side of the
mandrel B which for this purpose is preferably made hollow as shown. When the
mandrel. end does not protrude through its outer. casing into the atmosphere it
need neither be made hollow nor have the.aforesaid air holes, in which latter case
the volume of air between tube and mandrel and as further expanded by heat is
allowed to escape at the tube ends, or through slits d thereat into the surrounding
space which is to be at that moment and for that purpose wholly or partially
relieved from external moulding pressure. When the air is thus got rid of and
dilation of the tube prevented it reclasps the mandrel of its own accord and
becomes its own non-return valve. And an elastic band D or other encircling
medium may be applied over such slit or other opening to further help it in this
respect if necessary. These tubes may either be moulded straight or to the circle
of the wheels for which they are to be adapted, the latter by preference. This
process of embossing is intended to obviate the use of any outside or double
moulding tube or plate or any textile or other over all binding or wrapping; as
also the inversion of tube after removal from the mandrel.
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 :-
The method and means hereinbefore described of embossing or similarly shaping
sheet rubber tubing, consisting in the use of a forming mandrel indented or
otherwise shaped to the contour of the fiuished tube over which mandrel the tube
is placed whilst in a semi-cured and plastic state without any over-all external
wrapping and enclosed within a casing, air steam or other fluid under pressure
being then admitted to force the tubing into close.contact with the indented
surface of the mandrel whilst providing for the escape of air from the indentations,
whereby the tube across the area of each indentation is subjected to a state of
stretch and is caused to clasp the mandrel and assume its contour prior to or
concurrently with complete vulcanization, inversion of the tube being by this
method rendered unnecessary, all substantially as described.
Dated this 1st day of February 1897.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
2 St. Vincent Street, Glasgow, Agent for the Applicant.