Improved Puncture Proof Shield for Pneumatic Tyres.
Year: 1898

page_text: Improved Puncture Proof Shield for Pneumatic Tyres.
I, DAVID NAPIER, of of 306, Marshall Street, Jeppestown, Johannesburg, Trans-
vaal, South Africa, General Merchant, do hereby declare the nature of this
invention to be as follows:-
This invention has for object the manufacture and employment of thin steel
as a shield which is curved in cross section and with rolled edges; the ends are
free for the shield to be stretched over an ordinary pneumatic tyre and adjust
itself to grip.
The curvature of the shield is such that although it fits closely to the tube
or cover it has no tendency to, chafe or creep but the circumferential edges can
be protected by rubber fillets which may or may not come close to the edges
of the rim, or they may slightly overlap them.
The overlapped ends allow for inflation and should deflation occur from any
cause the shield will preserve the tyre from injury or of becoming detached,
the deflated tyre acting temporarily as a pad or cushion between the rim and
the shield.
1000
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said D. Napier.
COMPLETE SPECIFICATION.
Improved Puncture Proof Shield for Pneumatic Tyres:.
I, DAVID NAPIER, of 306, Marshall Street, Jeppestown, Johannesburg, Trans--
vaal, South Africa, General Merchant, 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 has for object, the manufacture and employment of thin-steell
or its equivalent as a shield which is curved in cross section with rolled edges,.
the ends are free for the shield to be stretched over an ordinary pneumatic tyre:
and adjust itself to grip.
The curvature of the shield is such that although it fits closely to the tube
or cover it has no tendency to chafe or creep but the circumferential edges. can

page_text: be protected by rubber fillets which may or may not come close to the edges
of the rim, or they may slightly overlap them.
The overlapped ends allow for inflation and should deflation occur from any
cause, the shield will preserve the tyre from injury or of becoming detached,
the deflated tyre acting temporarily as a pad or cushion between the rim and
the shield.
The annexed drawings show the application of my puncture proof shield and
as a protector to an inflated tube in the position it occupies in the tyre.
Figures 1 and 2 sectional elevation of an inflatable tyre with my shield covering
so much of the tread of the tube portion as is necessary and having a cover of
the usual construction fitted over it.
Figure 3 represents a sectional elevation of an inflatable tubeless tyre with my
puncture proof shield on the outside and the metal exposed as the tread, but it
may be enclosed in the body of the tyre as a protector to the inner surface
portion.
According to the view Figure 1, the shield A consists preferably of a strip,
of flexible thin sheet steel (of about the thickness of common tin plate) of a
supple character rolled into crescent shape and its side edges B, B, bent, lipped,
or rolled over or under the body to give stiffness at the edges, the strip, is then
curled into a ring formation with the ends C C as an overlap in order that the
band may be increased or decreased such as to protect a 26 inch or a 28 inch or
other size of wheel tube or tyre.
This shield can be located in the cover D and when placed on or over the
tube E either singly or in conjunction with the cover, the ends can have a
plate under them, and on which they can ride to prevent abrasion of the
inflatable tube E during expansion under the action of the air pump, the shield
opening out and extending and adjusting itself in circumference under the
internal air pressure until the tube E is fully inflated. The cover D is usually,
canvas lined and its contact with the steel protector A is of no moment.
G is the rim with its flange indents or annular channels for reception of the
wire or beaded edging H of the cover D which, as is well known, locates the
tube E permanently to the rim G, whether the tube be inflated or deflated unless
hand pressure from one of the sides is exerted to purposely remove it.
In practice, I find thin sheet steel of a soft and supple character, (the steel
however should not be too soft but yet flexible), will bear any amount of
indenting by sharp pointed articles, such as tacks on end, the sharp point or edges
of glass bottles, thorns, broken flint stones, and the like, especially where a
cover D is employed with a tyre, the point first having to penetrate a cushion
like medium and then a strong canvas before it can come into contact with the
steel shield which protects the tube E.
The plain, or rolled, or overlapped, or underlapped edges B of the shield A may
have a fillet of rubber, leather, leatherette, canvas, or other coating glued, or
otherwise cemented on, but as a rule the edges would be rounded off or burred
down to prevent any cutting action against the cover D or of the tube E.
I find the crescent shape of shield answers all kinds of road travelling, and
from the additional rigidity given to the rolled or coated edges of the shield,
all tendency to side slip is obviated.
I have at Figure 3 for convenience shown the outer face of the steel profector
or metal shield plain surfaced but it may be provided with projections of any kind
to obtain the necessary grip on the ground and to prevent skidding, and if
desired this metal shield may have a coating of rubber glued on, or a skin of
any material may be stretched over it to serve as the tread portion.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is;
As a puncture proof shield to a pneumatic tyre, the employment of very thin soft

page_text: supple steel, or equivalent metal, of ring shape and of crescent formation in, on, or
between an elastic expansible tubular or like tyre, the ends of the shield being
free with an overlap, as described and as represented on the annexed sheet of
drawings.
1
The 21st day of November 1898.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said David Napier.