New or Improved Means for Preventing the Puncture of Pneumatio Tyres.
Year: 1898

page_text: Date of Application, 24th Feb, 1898
Complete Specification Left, 7th Mar., 1898-Accepted, 9th Apr.,
1898
PROVISIONAL SPECIFICATION.
New or Improved Means for Preventing the Puncture of Pneumatio
Tyres.
I, DOUGLAS STUART-SPENS STEUART, of Pretoria, in the South African Republio,
Engineer, do hereby declare the nature of this invention to be as follows:-
Whereas in the methods hitherto employed for preventing the puncture of
pneumatic tyres, the dead weight of the tyre has been greatly increased and the
free motion of the particles of rubber have been both retarded and deflected in
such a way as to greatly lessen the elasticity of the tyre and consequently to reduce
both its ease and rate of motion; I have found that these objections are to a great
extent obviated by the construction of a tyre upon the principles herein described
which are based on an examination of the motive principles as illustrated in the
skins of snakes and the segments of the centipede.
My main object after rendering the tyres unpuncturable is to ensure free lines
of motion to the rubber particles composing the tyres both along the radii and the
circumferences of the circles formed by its transverse sections and also to a lesser
extent to ensure free movement of the rubber particles along the circumference
of the circle formed by the tyre itself when attached to the wheels.
I accomplish this in two ways:-
1. I employ a series of wires or cords of suitable elasticity which I attach inter-
nally along the basal or tread half of the tyre, along the channel of which they
run longitudinally parallel to one another forming a series of circles having their
centres in planes parallel to that containing the centre of the tyre itself when
attached to the wheel. The lowermost wire or cord encircles internally the basal
portion of the tyre, that portion supporting the wheel to which it is attached, the
uppermost pair of wires or cords is equidistant from the former and lie attached
to the tyre in the plane of the diameter of the circle formed by its transverse
section. Midway between these another pair of wires or cords is attached to the
tyre, but the number of these wires is not necessarily limited to a single pair. In
order to allow of the necessary movement of the rubber particles in the direction
of the circumference of the wheel, the circles formed by the wires or cords are each
divided into segments which are equal for the same circle, the segmental points
of division in one circle being opposite the segmental circumference of another
circle, thereby supporting the surface of the tyre. Similar circles of wire may
also be attached at intervals along the tyre to support its upper half.
I employ any substance of a suitable texture hardness, elasticity, and specific
gravity as my protecting medium, such as celluloid, horn, or aluminium and its
alloys. The substance employed is formed into suitably shaped plates of a proper
size, thinness, and temper, which are attached to the wires, or cords. Plate No. 1
is curved so as to lie close against the base of the tyre to which it is affixed by
means of a central attachment to the wire, its upper portions overlapping externally
on either side of the tyre at the pair of plates next above, which are sub-centrally
attached to the pair of wires, these plates similarly overlapping externally the

page_text: pair of plates next above which are also attached in a similar manner to the next
pair of wires. This completes one of the protective segments to which all others
are similar. The above described overlapping of the plates prevents any object
penetrating between them and together with their central attachment allows free
lines of motion to the rubber particles of the tyre both along the radii and the
circumference of the circle formed by its transverse sections to which circles the
different segments correspond. To ensure free lines of movement to the rubber
particles along the circumference of the circle formed by the tyre when attached
to the wheel, the segments are made sufficiently narrow and each one owing to
the central attachment of its component plates overlaps externally the one next
to it which it does in such a way that the overlapping edges turn away from the
ground as the wheel revolves so as to prevent any objects penetrating between
them. The difference in shape of the circle produced by the progressive over-
lapping of the segments must be allowed for in the construction of the rubber
tyre, otherwise the segments must overlap and underlap alternately.
My second method of protecting the tyres is one in which the mean lines of
motion of the rubber particles are more closely followed, the principles of conic
sections allowing the ellipse to represent more accurately the planes in which the
protective segments should lie to ensure the greatest advantage of minimum friction
and resistance with the maximum elasticity. To utilise this principle, I employ
a fine spiral spring of suitable temper and elasticity with which I completely encircle
the tyre internally, the two ends of the spring being unjoined. A series of plates
are then attached to the basal half of the channel of the tyre as in the preceeding
description but the central point of attachment of each plate is situated on a coil
of the spiral spring instead of on a circular wire; the basal plates being fixed on
the lowermost portions, and the lateral plates, equidistant therefrom being fixed
on either side of the spiral coils which represent in each case the longest axis of
the plates with which their long edges lie parallel. The methods of attachment
and overlapping of the different segments and their component plates correspond
to those previously described.
In both cases the plates will be kept close and pressed against the outer tyre
by the inflated rubber tyre, within, between which and the protective plates either
a thin rubber or canvas cover may be placed to guard against friction on the
inflated tyre by the plates whose edges may or may not be doubled over each other.
The above described arrangements increase but slightly the weight of the tyre
while by reduction of friction they preserve its elasticity at the same time render-
ing it unpuncturable by all ordinary means and consequently lessen to a great
extent the wear on the pneumatic tyres themselves.
Dated this 24th day of February 1898.
BOTICATION.
New or Improved Means for Preventing the Puncture of Pneumatic
Tyres.
I, DOUGLAS STUART-SPENS STEUART, of Pretoria, in the South African Republic,
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:-
Whereas in the methods hitherto employed for preventing the puncture of
pneumatic tyres, the dead weight of the tyre has been greatly increased and the

page_text: free motion of the particles of rubber have been both retarded and deflected in
such a way as to greatly lessen the elasticity of the tyre and consequently to reduce
both its ease and rate of motion; I have found that these objections are to a great
extent obviated by the construction of a tyre upon the principles herein described
which are based on an examination of the motive principles as illustrated in the
skins of snakes and the segments of the centipede.
My main object after rendering the tyres unpuncturable is to ensure free lines
of motion to the rubber particles composing the tyres both along the radii and the
circumferences of the circles formed by its transverse sections and also to a lesser
extent to ensure free movement of the rubber particles along the circumference
of the circle formed by the tyre itself when attached to the wheels.
I accomplish this in two ways:
1. I employ a series of wires or cords (W1¹, W2¹, W3º, 1W, 2W, Fig. 2) of
suitable elasticity which I attach internally along the basal or tread half of the
tyre, along the channel of which they run longitudinally parallel to one another
forming a series of circles having their centres in planes parallel to that containing
the centre of the tyre itself when attached to the wheel. The lowermost wire or
cord W30 Fig. 2 encircles internally the basal portion of the tyre, that portion
supporting the wheel to which it is attached, the uppermost pair of wires or
cords W1 1W is equidistant from W.30 and lie attached to the tyre in the plane
of the diameter of the circle formed by its transverse section as shown in Fig. 2.
Midway between W11, 1W and W.30, another pair of wires or cords W.21, 2W is
attached to the tyre, but the number of wires between W1, 1W and W.3° is not
necessarily limited to a single pair. In order to allow of the necessary movement
of the rubber particles in the direction of the circumference of the wheel indicated
by the arrow M Fig. 2 the circles formed by the wires or cords are each divided
into segments which are equal for the same circle, the segmental points of division S
in one circle being opposite the segmental circumference R of another circle,
thereby supporting the surface of the tyre. Similar circles of wire may also be
attached at intervals along the tyre to support its upper half.
I employ any substance of a suitable texture hardness elasticity and specific
gravity as my protecting medium such as celluloid, horn, or aluminum and its
acys. The substance employed is formed into suitably shaped plates of a proper
size, thinness, and temper, which are attached to the wires or cords as shown in the
diagram Fig. 2. Plate No. 1 is curved so as to lie close against the base of the
tyre to which it is affixed by means of a central attachment A to the wire W.3º,
its upper portions overlapping externally on either side of the tyre at OV. 2 the
pair of plates next above 21, 2, which are sub-centrally attached to the pair of
wires W2, 2W, at A these plates similarly overlapping externally at OV. 3 the
pair of plates next above 31, 3 which are also attached in a similar manner at A
to the next pair of wires W11, 1W. This completes one of the protective segments
to which all others are similar. The above described overlapping of the plates
prevents any object penetrating between them and together with their central
attachment allows free lines of motion to the rubber particles of the tyre both
along the radii and the circumference of the circle formed by its transverse sections
to which circles the different segments correspond.
To ensure free lines of movement to the rubber particles along the circumference
of the circle formed by the tyre when attached to the wheel (see direction of
arrow M) the segments are made sufficiently narrow and each one owing to the
central attachment of its component plates overlaps externally at OV1 the one
next to it which it does in such a way that the overlapping edges turn away from
the ground in direction of arrow M as the wheel revolves so as to prevent any
object penetrating between them. The difference in shape of the circle produced
by the progressive overlapping of the segments must be allowed for in the con-
struction of the rubber tyre T, otherwise the segments must overlap and underlap
alternately.
My second method of protecting the tyres is one in which the mean lines of

page_text: motion of the rubber particles are more closely followed, the principles of conic
sections allowing the ellipse to represent more accurately the planes in which the
protective segments should lie to ensure the greatest advantage of minimum fric-
tion and resistance with the maximum elasticity. To utilise this principle I
employ a fine spiral spring of suitable temper and elasticity with which I com-
pletely encircle the tyre T Fig. 1 internally, the two ends of the spring Sp being
unjoined. A series of plates, 1, 2, 3, are then attached to the basal half of the
channel of the tyre as in the preceeding description Fig. 2, but the central point of
attachment A of each plate is situated on a coil of the spiral spring Sp instead of
on a circular wire; the basal plates being fixed on the lowermost portions, and
the lateral plates 2, equidistant therefrom being fixed on either side of the spiral
coils which represent in each case the longest axis of the plates with which their
long edges lie parallel. The methods of attachment and overlapping of the
different segments and their component plates correspond to those previously
described. In both cases the plates will be kept close and pressed against the
outer tyre T by the inflated rubber tyre within, between which and the protective
plates either a thin rubber or canvas cover may be placed to guard against friction
on the inflated tyre by the plates whose edges may or may not be doubled over
each other.
The above described arrangements increase but slightly the weight of the tyre
while by reduction of friction they preserve its elasticity at the same time
rendering it un-puncturable by all ordinary means and consequently lessen to a
great extent the wear on the pneumatic tyres themselves.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is: -
1. In the construction of a protective cover for preventing the puncture of
pneumatic tyres, plates of celluloid, horn, aluminum, or other substance of suitable
hardness, elasticity and specific gravity centrally attached to a spiral spring, along
the base and sides of the coils of such spring in the form of overlapping segments
creating a series of semi-circles along the inside of the outer tyre each component
plate of which either overlaps or underlaps those adjoining it the arrangement
being such that the overlanning edges of the plates are placed opposite to he
direction in which the wheel revolves so as to prevent the inter-penetration of any
object which may have punctured the outer tyre.
2. In the construction of a protective cover for preventing the puncture of
pneumatic tyres segmentally arranged overlapping plates of celluloid, horn,
aluminium, or other substance of suitable hardness, elasticity, and specific gravity
in combination with a number of wires or cords of suitable elasticity attached
internally to the lower (outside) half of the outer tyre, the segmentally arranged
overlapping plates, being centrally attached along the wires which run internally
around the circumference of the tyre, a row of plates being fixed to each wire circle
which is divided into segments so that the segmental division of one circle is
opposite the segmental circumference of another circle, thus supporting the tyre
and increasing its elasticity substantially as described.
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, W.C., London.