Improvements in the Treatment of Hides or Skins for use in the Manufacture of Leather Tires for Wheels and other purposes.
Year: 1898

page_text: Improvements in the Treatment of Hides or Skins for use in the
Manufacture of Leather Tires for Wheels and other purposes.
I, JOHN MUIR, of Mains House, Beith, in the County of Ayr, North Britain,
Tanner, do hereby declare the nature of this invention to be as follows, that is
to say:-
My said invention has for its object the treatment of hides or skins for use in⚫
the manufacture of leather tires for wheels and other purposes so that such leather
will be more economical, more elastic, and more durable than as hitherto made.
In carrying out my invention I employ the skins of pigs or boars or other
suitable skins and I utilise and enhance their natural peculiarities rendering
them advantageously suitable for the purposes specified by special treatment or
processes.
I do not use lime throughout the preliminary process—the usual mode of treat-
ment because thereby the skin is unhaired and the fibre of the leather is dis-
integrated, the inherent natural oils, gelatin, and. albumen, are deteriorated or
destroyed, these being the substances which give natural elasticity and dura-
bility to the skin. I may partially employ lime or I, to a greater or less extent
employ a calcium sulphide, or mixture of sulphides, or what is known as tank
waste or I employ any other suitable known substance such as sulphide of
sodium, or caustic soda, to a greater or less extent, or other substances of an
alkaline or acid character which enables me to preserve in the skin the hair or
bristles or such portion of them as I may desire to retain, to obtain increased
resiliency or other effects in the leather product. I also preserve thereby the
aforesaid inherent oil, albumen, and gelatinous substance in the skin, the finished
product being by their presence rendered capable of resisting in a higher degree
than otherwise the attrition wear to which the said leather for tires and other
uses is specially subjected.
I may also employ any known substance such as salt, or alum, or any acid
in addition to the aforesaid tanning process which will assist in improving or
fixing those ingredients and the hair more permanently in the skin.
The skin with, the hair or bristles retained therein as described I then tan by
ordinary tanning or other known processes.
Taking advantage of its natural porosity I next incorporate with the treated
skin a filling or partially filling substance, which renders the skin more service-
able. For this purpose I may use rubber or any suitable rubber substitute or
composition, or wax, or any suitable oleaginous substance or waterproofing com-
pound, or. I may add without incorporation such substance as will give increased
Hexibility to the leather. The filling substance may be applied in solution the
solvent being afterwards removed by evaporation; or the filling substance may
be forced into the leather by pressure, or otherwise applied.

page_text: The leather thus treated may be formed into a tire in the manner practised
with ordinary or other kinds of leather.
Dated this Sixteenth day of April 1898.
EDMUND HUNT,
Applicant's Agent.
Improvements in the Treatment of Hides or Skins for use in the
Manufacture of Leather Tires for Wheels and other purposes.
I, JOHN MUIR, of Mains House, Beith, in the County of Ayr, North Britaiu,
Tanner, 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:-
My invention has for its object the treatment of hides or skins for use in the
manufacture of leather tyres for wheels and other purposes, so that such leather
will be more economical, more elastic, and more durable than as hitherto made.
My invention is especially designed for the purpose of providing an efficient
substitute for rubber for the tyres of what are known as leather-shod wheels.
Various attempts have been made to produce a leather shod wheel which shall
have greater durability, and a certain amount of resilience like a rubber shod
or pneumatic tyre, by placing layers of leather within a suitable rim, such layers
being either superposed or in the form of discs placed side by side within the
rim. But such tyres as hitherto constructed possess very serious drawbacks,
being deficient in elasticity and in durability, and have consequently proved not
to be a commercial success.
My invention provides a thoroughly efficient, water-proof, and durable elastic
tyre, which by reason of its nature, and of the special treatment hereinafter set
forth, possesses the qualities of more or less vulcanized india rubber, and is con-
sequently specially fitted for the purpose in view.
Ordinary leather tanned in the usual manner may be compared to a bundle
of loosely connected fibres, having a large capacity for absorbing moisture, and
this leather when subjected to extreme pressure, as is usually the case in the
construction of leather tyres, suffers materially from disintegration by the crush-
ing of the fibres, which increases its tendency to wear at the edge. Moreover this
leather rapidly absorbs moisture, and may swell and damage the rim, and in
any case the moist leather wears still more rapidly in contact with the ground.
The examination of ordinary leather makes it evident that nature's plan of
construction of the ordinary original hide is to build up a great number of small
interlacing fibres which are held together by a cement-like substance.
In the ordinary process of tanning, the lime by its swelling and caustic action
destroys this substance, and weakens and disintegrates the small fibres. The
principal object of the lime process is to make room for tanning and other weighty
substances in order to produce a full yield of commercial leather. This com-
paratively spongy leather is then further disintegrated as already explained, by
the pressure necessary for the building up of the tyre, so that when it is exposed
in the wheel to the severe wear of vehicular traffic the leather easily grinds away,
having been actually specially prepared for rapid wear, firstly by the caustic
action of the lime, and secondly by the further bruising of the already weakened
fibres by the compression.
Now, I have discovered that the skin of the pig is the substance most suited

page_text: for the purpose in view. Pig skin differs from other hides ordinarily known in
commerce in 'that it is formed essentially of a dense and practically homogeneous
mass of almost horn-like substance, and not fibrous in its nature as the skins of
other domestic animals commonly used for the preparation of leather. Moreover,
it possesses when treated as I propose a greater flexibility because supplied
naturally with oily, gelatinous, and albuminous matter, which, when thus pre-
served, give it rubber-like characteristics, and it is by nature eminently suited
to resist attrition in a far higher degree than rubber. This natural advantage of
pig skin may be greatly preserved and enhanced by proper preparation for the
purpose in view. Instead of soaking the hide in the lime pit as usual until the
bristles are removed by the action of the lime and the commencement of putre-
faction, this action being destructive of those "oily, gelatinous and albuminous"
ingredients, and of its naturally homogeneous character, I remove the upper part
of the bristles by mechanical means, and then by means of a suitable reagent,
such for instance as sulphide of calcium or of barium, or by means of the waste
products containing sulphide of lime, known as "tank waste" or any other suit-
able substance of an acid or alkaline nature, I complete this substituted process for
the ordinary depilatory one. The result of this treatment is to leave the roots
of the bristles in the hide to a greater or less extent as required, thus adding
greatly to the flexibility of the leather after compression, and to its impervious-
ness, because the bristles in pig skin are deep-set, and their removal in the
ordinary manner leaves a considerable aperture in the skin, which in my process
remains closed by leaving the root in it, which root is the strongest and most
resilient part of the bristle, and materially assists the aforementioned process in
giving the pig skin rubber-like characteristics thus making the skin a suitable
rubber substitute.
I may altogether dispense with the liming process commonly used, or I inay
employ the same to a limited extent for the purpose of somewhat swelling the
hide, care being taken not to cause the bristles to fall out, or to use so much lime
as to burn and destroy the naturally strong bristle or disintegrate and make the●
pig skin less homogeneous.
The antiseptic action of the lime if used moderately and usefully, swells the
hide, and preserves the bristle roots from the alkaline action of the other ingre-
dients used.
I may also employ any known substance, such as salt or alum, or an acid in
addition to the aforesaid process which will assist in improving or fixing the
oily, gelatinous, or albuminous" ingredients, and securing the bristles more
permanently in the skin.
The hide is then further tanned by any suitable chemical process, preferenti-
ally such for instance as that known as the chrome process, or I may employ
other tanning materials.
After the tanning process is completed I may further treat the hide with a
filling or water-proof substance. For this purpose I may use rubber or any suit-
able rubber substitute or composition, or artificial or mineral wax, or any suit-
able oleaginous substance or waterproof compound, or I may add, without
incorporation, such substances as will give increased flexibility to the pig skin,
this being the most porous of all leather, and. therefore most suitable for this
treatment.
The filling substance may be applied in solution, the solvent being afterwards
removed by evaporation; or the filling substance may be forced into the leather
by pressure, or otherwise applied.
The leather thus prepared is cut into pieces of the required size and shape,
and placed in or around the tyre as usual, and is then subjected to compression
to the required extent to give it the requisite hardness and coherence, and pre-
vent indentation by road metal and the like.
In the case of my improved leather this compression causes the bristle roots
contained in the adjacent pieces to interlock or penetrate into the pores or part

page_text: of the piece next to them to a greater or less extent, and thus more effectively
to unite the skins, and add to the coherence and resiliency of the tyre.
The tyre thus constructed is found to be superior in point of elasticity, imper-
viousness, and durability to any other leather tyre hitherto known.
*
i)
For purposes other than the preparation of wheel tyres, my process may require
slight modification without, however, departing from the principle thereof, thus
pig skin leather tanned in the manner set forth has proved specially useful for
the construction of nose-bags for horses and similar purposes, in which an imper-
vious or rubber-like leather is desired, or for purposes where leather capable of
resisting attrition in a high degree is required.
*.
In the accompanying drawings
"
Fig. 1 shews a tyre of sections or discs arranged vertically to the rim and
transversely to the plane of the wheel.
Fig. 2 shews a part of a wheel with a tyre of strips arranged vertically to the
rim and longitudinally to the plane of the wheel.
.In these drawings, a indicates the wheel, 6 the rim, and c the leather tyre.
The wheels and rims may obviously be of any suitable shape or section.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is-
1. The improvement in the treatment of pig skin or other hides or skins by
partially unhairing the same without full liming, and subsequent tanning by
chemical means, and finally waterproofing the leather substantially as, and for
the purposes set forth.
2. The improved leather tyres for wheels composed of multiple layers of
partially unhaired pig skin, said layers being compressed together and united
by the interpenetration of the bristle ends, substantially as described.
3. The improved water proof pig skin leather wheel tyres constructed and
operating substantially a
as described and illustrated in the accompanying drawing.
1
101
1
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.