IMPROVEMENTS IN THE ADAPTATION OF INDIA-BUBBER AND COMPOUNDS THEREOF TO WHEELS.
Year: 1860

page_text: LETTERS PATENT to Robert Offord, junior, of 79, Wells Street, Oxford
Street, in the County of Middlesex, Carriage Builder, for the Invention
of "IMPROVEMENTS IN THE ADAPTATION OF INDIA-BUBBER AND COMPOUNDS
THEREOF TO WHEELS.
Sealed the 3rd May, 1861, and dated the 29th November 1860.
PROVISIONAL SPECIFICATION left by the said Robert Offord at the
Office of the Commissioners of Patents, with his Petition, on the
29th November 1860.
I, ROBERT OFFORD, junior, of 79, Wells Street, Oxford Street, in the County
of Middlesex, Carriage Builder, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE ADAPTATION OF INDIA-BUBBER AND COX-
POUNDS THEREOF TO WHEELS," to be as follows:-
The present Invention consists of an improved mode of constructing tyres
of india-rubber or compounds thereof for wheels by employing two kinds of
india-rubber, commonly known as soft and hard, which are chemically and
firmly attached to each other during the process of vulcanising. By this
means the outer surface still retains the required elasticity whilst the inner
surface is sufficiently firm and unyielding to be more easily and perfectly
attached to the felloes and inner parts of the wheel. In some cases wheels
(particularly those of small size) may also be formed wholly or in part of india-
rubber or its compounds, with a tyre of soft rubber with metal or other

page_text: centres. Tyres may consist of a whole circle or two or more parts. The
above is a description of the nature of the said Invention, the details whereof
may possibly be varied in practice.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Offord in the Great Seal Patent Office on the 25th
May 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
OFFORD, of 79, Wells Street, Oxford Street, in the County of Middlesex,
Carriage Builder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of November, in the year of our
Lord One thousand eight hundred and sixty, in the twenty-fourth year of Her
reigu, did, for Herself, Her heirs and successors, give and grant unto me,
the said Robert Offord, Her special licence that I, the said Robert Offord,
my executors, administrators, and assigns, or such others as I, the said Robert
Offord, my executors, administrators, and assigns, should at any time agrec
with, and no others, from time to time and at all times thereafter during the
term of years therein expressed, should and lawfully might make, use,exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
ADAPTATION OF INDIA-EUBBER AND COMPOUNDS THEREOF TO WHEELS," upon the con-
dition (amongst others) that I, the said Robert Offord, ny executors or
administrators, should by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what mauner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Offord, do hereby declare the
nature of my said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following state-
ment:-
The present Invention consists, first, of an improved method of making
and adapting india-rubber tyres to wheels; and secondly, in making castor
wheels or bowls of india-rubber, with or without metal centres. There are
two kinds of vulcanised india-rubber already well known to manufacturers,
one of which is soft and elastic, the other commonly known as "hard" or

page_text: The
"vulcanite." It is also known that these two kinds of material will chemically
unite in the process of vulcanisation, and the present Invention consists in
adapting this united compound to the purposes before mentioned, the hard.
rubber forming the ground work, and the soft or elastic material forming the
outer surface. By means of the hard substance underneath I obtain a much
firmer fixture to the felloes of the wheel than has yet been possible, as also
great lightness in appearance, whilst the outer substance ensures the elasticity
necessary for quietness and ease, when in contact with the roadway.
width and thickness of the tyres must be varied according to the strength and
size of the wheel, a medium size being about 1 inch wide by 1 inch thick,
I prefer in general that the outer surface should be about two-thirds of the
thickness, and the under surface or hard material about one-third ; but these
proportions may be varied as found desirable. In most cases it is an advantage
by moulding or otherwise to round off the sharp edges of the tyre, thus
rendering it less liable to cut. The mode of fixing (for wood wheels) is to
ring the metal with an iron tyre, shrunk on, which iron tyre should be as
light as possible consistent with the strength required for drawing the different
parts together. Where the india-rubber is in one continuous piece the outer
surface of this iron tyre and the inner surface of the hard rubber, should be
accurately fitted so as to drive on pretty tight, and it is then secured in place
by a sufficient number of bolts or rings, the bolt heads being inserted through
the outer or elastic surface as shewn in the Drawings, and screwed or rivetted
on the inside of the felloe. Another method which I adopt in some cases is
to secure the requisite number of nuts into the hard material before vulcanizing,
and to provide screws at proper intervals from the inner side of the felloe
either into the said nuts, or if the nuts are dispensed with into the hard
material itself. The above description relates to carriage wheels as ordinarily
made with wood felloes, spoke, stock, and iron bush or box. Another mode
of applying my improved india-rubber tyres is to make the wheel wholly of
metal. The outer rim and spokes being wrought, and the centre box of
cast iron or gun metal or for smaller wheels certain parts may be of brass,
and in these cases I should prefer to vulcanize such tyres at once, on to the
wheel itself, using metal bolts or projections when necessary to render the
fixing additionally secure. Another application of the said improved tyres
is for covering cast-iron truck wheels of various sizes by vulcanising the india-
rubber tyre at once on to the wheel itself. The hard rubber or vulcanite
forms the first covering next to the iron; this will take firm hold of the metal
surface, but where practicable I prefer a groove or rib in the casting as an
additional security. The elastic or outer surface is then added, and by its

page_text: chemical adhesion during the process of vulcanizing forms a durable and
elastic noiseless wheel tyre. Another application of my Invention is to
castor wheels or bowls. In this case I make the wheel itself of hard rubber
or vulcanite (moulded or otherwise) with or without a metal bush or centre,
and with an external surface of elastic rubber chemically united as before
described in the process of vulcanising.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a wheel of the kind ordinarily in use for carriages; A is
the stock; B, B, the spokes; and C the felloes; D is a light iron tyre shrunk
on as usual; E and F represent the improved india-rubber tyre, E being 1
the hard rubber-or vulcanite, and F the elastic or outer surface; G, G, G,
(see Fig. II.) are the bolts by which the hard rubber or vulcanite is fixed to
the felloes, the bolt heads being let through the outer surface F, and taking
firm hold of the hard material E. Figs. II. and III. are sections in full size
of the felloe and tyres shewing the position of the bolts by means of which
the india-rubber tyre is held in place. Fig. IV. a section of the same shewing
a variation in the form of the bolt, the head being reversed, and the point of
the screw entering the hard rubber E.
Fig. V. represents a front view of the felloe and tyres, shewing another
mode of fixing by means of the bolt G, the head of which is inside the
felloe C and the point or screwed end enters a nut embedded into the hard
material E.
Fig. VI. represents an iron wheel in which the stock or centre is of iron
or some other metal; the spokes and outer rim are also of metal. The same
letters represent the different parts as before. In this case the tyre is
vulcanised on to the wheel itself, and the mode of fixing may be somewhat
varied, care being taken that the bolts or screws when used are sufficient
in number to effectually keep the tyre in place.
Fig. VII. represents an iron truck wheel of the usual kind with my
improved tyre vulcanised on, E is the hard rubber or vulcanite, and F the
elastic surface. If the iron be rough from the mould it will sufficiently
adhere in most cases without bolts or other fixing, but in casting new wheels
I prefer to have a groove or rib left in the casting which effectually secures
the tyre in its place (see Figs. VIII. and IX.)
Fig. X. represents a castor wheel made of hard india-rubber, with a brass
centre, and an outer rim or tyre of the elastic material. Fig. XI. is a section
of the same; these castor wheels may either be made singly in moulds, or in
tubes of convenient length cut off to the required thickness in a lathe, the

page_text: advantage of moulding especially for the larger sizes, would be the encomizing
of the material by shaping out the sides as shewn in Fig. XII.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I may here remark that I do not confine myself
to the precise modes of fixing herein described, and that the tyres themselves
of large wheels may be made either in one whole piece, or in three or more
pieces, as most convenient, in which case the bolts or fastenings must be
varied accordingly, also when I use the terms "hard" and "soft" I would
observe that there are great variations in degrees of "hardness" even in the
material commonly known as "soft" or elastic rubber; and likewise the
vulcanite or hard rubber is not without some degree of elasticity, but what I
claim as new and desire to secure in the present Invention is the adaptation
of india-rubber of two kinds or densities united chemically together, in and
for the construction of wheel tyres and castor wheels, as herein set forth and
described.
In witness whereof, I, the said Robert Offord, have hereunto set my
hand and seal, this Twenty-third day of May, in the year of our Lord
One thousand eight hundred and sixty-one.
נוממחנות
Teruno.
Signed and sealed in my presence,
F. W. CAMPIN, Patent Agent,
156, Strand.