A New or Improved Mode and Means of Forming Tubular Plaquets and other Tubular Articles of India Rubber, Ebonite, and the like.
Year: 1892

page_text: Date of Application, 31st May, 1892
Complete Specification Left, 27th Feb., 1893-Accepted, 13th May, 1893
PROVISIONAL SPECIFICATION.
A New or Improved Mode and Means of Forming Tubular Plaquets
and other Tubular Articles of India Rubber, Ebonite, and
the like.
We, WILLIAM BARR, Junior, Grocer and Wine Merchant, of St. Mary's
Street, and DAVID MCKAY, Goldsmith, of Millburn Street, both in the Town
and County of Kirkcudbright, do hereby declare the nature of our invention to
be as follows:-
This invention has reference to and comprises a new or improved method or
mode and means of forming tubular plaquets and other tubular articles, and
specially suitable for forming tubular plaquets of vulcanized dental rubber for use
on the nose frames of eye-glasses, but also applicable for forming other tubular
articles especially those of small bore or diameter of india rubber, ebonite, and the
like, of square, flat, round, oval, fluted, polygonal, or other shapes.
The improvements consist, first and essentially in the use of brass, copper,
German silver, iron, or other soft wire or metal with smooth surfaces for a central
core, that is, metal which is capable of being drawn, and of being softened before
being covered or packed with the dental rubber or material which is to form the
plaquet or tubular article. And in drawing or lengthening said soft metal core in
a stretching machine, after formation and vulcanization of the tubular article, so
that it will become contracted and easily withdrawn from the plaquet or article
and leave the latter free in its finished state.
In carrying our improved method into practice under one arrangement to form
tubular plaquets of vulcanized dental rubber, say of rectangular or flat shape, we
take a metallic tool or mould formed with a series of parallel Ushaped channels,
which may be made by soldering a series of parallel plates or strips set vertically
on edge at suitable distances apart on a bottom sole plate and have thin flat
parallel horizontal plates or strips soldered to the bottom plate in the lower part
of the spaces between the vertical rods. A thin sheet or layer of dental rubber is
then laid horizontally over said tool and by exerting pressure, as say, on a portable
flat plate or surface placed above the rubber the latter gets embedded in the
U shaped channels. A suitable length of previously softened thin flat wire or
metal with smooth surfaces is laid flat in the centre of each of the parallel
channels over the lower sheet of dental rubber as a metallic core. A second sheet
or top layer of dental rubber is then laid over the rod thick enough to fill more
than the remaining spaces of each of the channels the excess of thickness over the
vertical edge plates serving to keep the plaquet lengths in the form of. a sheet or
series of tubes, and so make them more easily and expeditiously handled. Pressure
is then exerted on the moulding tool and the dental rubber adheres to the core rods
embedded in same and to its own edges in each of the channels. The sheets or
tubes of these moulded plaquet lengths with the metal cores in the centre, are then
placed in plaster of paris moulds, and they are afterwards vulcanized to any
desired degree of hardness in a hot close chamber in the usual manner in which
dental rubber is vulcanized. The two free ends of the soft wire or metal central
core of each tubular plaquet so formed are then placed in a wire stretching machine,
and after stretching the core a little it can be readily withdrawn leaving the
finished tubular plaquet free.
Dated the 30th May 1892.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.

page_text: COMPLETE SPECIFICATION.
A New or Improved Mode and Means of Forming Tubular Plaquets
and other Tubular Articles of India Rubber, Ebonite, and
the like.
We, WILLIAM BARR Junior Grocer, and Wine Merchant of St. Marys
Street, and DAVID MCKAY, Goldsmith of Millburn Street, both in the Town
and County of Kirkcudbright, do hereby declare the nature of our invention,
and in what manner the same is to be performed to be particularly described, and
ascertained in and by the following statement in writing that is to say :—
This invention has reference to and comprises a new or improved method or
mode and means of forming tubular plaquets, and other tubular articles, but
specially suitable for forming tubular plaquets of vulcanized dental rubber for use
on the nose frames of eye glasses, also applicable however for forming other tubular
articles, especially those of short length of small bore or diameter and made of
dental rubber, ebonite, and the like, and of either square flat, round, oval, fluted
polygonal, or other shapes.
The improvements consist, first, and essentially in the use of brass, copper,
German silver, iron or other wire or metal of smooth surface and suitable temper
for a central core, that is, metal which is capable of being softened before being
covered or packed with the dental rubber or inaterial which is to form the plaquet
or tubular article, and of being withdrawn by a process of drawing or lengthening
said soft metal core-in a stretching machine or otherwise after formation and
vulcanization of the tubular article thereon-anyhow so that it will become
contracted and easily withdrawn from the plaquet or article, and leave the latter
free in its finished state.
In carrying our improved method into practice under one arrangement to form
tubular plaquets of vulcanized dental rubber say of rectangular or flat shape for
use on nose frames of eyeglasses we take a metallic tool or mould formed with
a series of parallel U shaped channels, which may be made by soldering a series of
parallel plates or strips set vertically on edge at suitable distances apart on a
bottom sole plate, and have thin flat parallel horizontal die-impressioned plates or
strips between same soldered to the bottom plate in the lower part of the spaces
between the vertical rods.
A thin sheet or layer of dental rubber is then laid horizontally over said
tool, and by exerting pressure, as say on a portable flat plate or surface placed
above the rubber the latter gets embedded in the U shaped channels. A suitable
length of previously softened thin flat wire or metal with smooth surfaces is then
laid flat in the centre of each of the parallel channels over the lower sheet of dental
rubber and serves as a metallic core. A second sheet or top layer of dental rubber
is then laid over these parallel core rods thick enough to fill more than the
remaining spaces of each of the channels the excess of thickness over the vertical
edge plates serving to keep the plaquet lengths in one namely in the form of a sheet
composed of a series of short tubes which can be easily and expediously handled
when being cleaned after vulcanization. Being packed and pressure being exerted
on the moulding tool, the dental rubber, adheres to the core rods embedded in same,
and to its own edges in each of the channels. The tubes or sheets of tubes of these
moulded plaquet lengths with the metal cores still in their centres are then placed
in plaster of paris moulds and vulcanized to any desire degree of hardness in a hot
close chamber, in the usual manner in which dental rubber is vulcanized. The free
ends of the soft wires or metallic central cores of tubular plaquets so formed, are
then placed in a wire stretching machine and after stretching the cores a little they
can be readily withdrawn, so leaving the tubular plaquets free.
1

page_text: Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
First. The herein described method of forming tubular plaquets, and other
tubular articles of dental rubber, ebonite and the like, consisting, in using a core or
a series of parallel cores of metal, which after being softened is or are covered or
embedded in the dental rubber or other material which is to form the tubular
article, and subjected to pressure within a mould, and subsequently after formation
and vulcanization of the tubular articles thereon are removable by the drawing or
the lengthening of said cores in a stretching machine or otherwise anyhow so that
they will contract and be easily withdrawn from the finished article, substantially
as set forth.
Second. In a method or system of forming tubular plaquets and other short
tubular articles of dental rubber, ebonite and the like, the use of a core formed
from metal capable of being softened and drawn substantially as and in the manner
set forth.
Third. In a method or system of forming tubular plaquets, and other short
tubular articles of dental rubber, ebonite, and the like, the combination and use of
a series of parallel cores formed from metal capable of being softened and drawn,
substantially as and in the manner set forth.
1000
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.