Improvements in, and relating to, Pneumatic Tyres.
Year: 1897

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c. Act, 1883) as required by
the decision of the Comptroller General of the 14th day of June 1898.
Date of Application, 12th Mar., 1897
Complete Specification Loft 11th Inn 1000
1000
PROVISIONAL SPECIFICATION.
Improvements in, and relating to, Pneumatic Tyres.
WILLIAM EDWARD CROWTHER, 88, Sandy Lane, Chorlton-cum-Hardy, near
Manchester, Mechanical Expert and Inventor, do hereby declare the nature of
this invention to be as follows:-
In pneumatic tyre covers which have their edges stiffened transversely for the
purpose of forming continuous hooked edges of a flexible nature as described in
my Specification No. 4813 of 1895 I propose to effect the stiffening by enclosing
within the edges a continuous band of fretwork of thin sheet metal. The fret is
formed by punching or cutting out strips extending nearly across the band, from
each edge alternately, so that the remaining metal is a fret of zig-zag form
possessing sufficient longitudinal flexibility and transverse stiffness for the
intended purpose.
With a view to the accurate and expeditious turning over of the stiffened
edges into hooked form, whether they are fitted with crimped wire or the fret just
described, I make use of a pair of discs or wheels in the same plane and carried
on separate spindles. One of the wheels has a comparatively sharp edge which
takes into a groove cut in the flat edge of the other, ample clearance being
allowed. This pair of wheels being revolved by power and the edge of the tyre
cover passed or fed between them, the result is that the edge is continuously
doubled up longitudinally into hook or U section. The edges of the wheels may
be roughened or milled to prevent slipping of the work. To press closer together
the sides of the hook or UI pass it between a pair of shaped rolls, at the same
time laying in the root of the U, a wire of suitable thickness and section which
can be slipped out of the hook after the operation is completed.
In forming a pattern of ridges & hollows for the tread of the cover to prevent
or minimize side-slipping I divide the tread into two or more longitudinal strips
and give to the surface of each a rocking curvature, or tilting, from side to side
proceeding along the tread of the tyre. The strip surfaces are parallel at
corresponding points of adjacent strips. I may make the rocks or tilts alternately
long and short, both longitudinally and transversely when the points of greatest
inclination of the surfaces coincide longitudinally in adjacent strips. Instead of
taking the strips straight along the tread I may laterally wave or meander them
in addition to rocking their surfaces from side to side as described.
To increase the staunchness of air valves for pneumatic tyres in which a sleeve
or a lining of rubber tube is used upon the outside or within the interior of the
air plug as described in Woods Specification No. 4175 of 1891 and Pauzetta's
Specification No. 20970 of 1893, I form sharp ridges upon the cylindrical seat of
the rubber tube either externally or internally as the case may be. These ridges

page_text: are pressed into the rubber by its own elasticity and the pressure
of the air and so prevent the air leaking back along the minute furrow usually
found along the joint of the tubing, and improve generally the staunchness of
the seal. To prevent risk of the rubber tube in the Pauzetta valve being blown
out of its place by forcible pumping I form the retaining pin of hard metal
such as German silver and before driving it into position I scratch upon it longi-
tudinal burrs or ridges which take forcible hold upon the rubber.
To prevent the outer or pinned end of the rubber expanding into a head and
choking the air passage at the entrance, I employ an extra pin parallel to and a
short distance away from the first or I may replace the two pins by a slip of metal.
Dated this Eleventh day of March 1897.
I, WILLIAM EDWARD CROWTHER, of 88, Sandy Lane, Chorlton-cum-Hardy, near
Manchester, Science and Art Teacher, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
This invention relates to the material for stiffening the edges of a pneumatic
tyre cover, for the purpose of forming continuous hooked edges of a flexible
nature as described in my former Specification No. 4813 of 1895; to a tread sur-
face of a tyre cover for the prevention of side slip, and to a manner of securing
perfect staunchness and other advantages in the air plug of pneumatic tyre valves,
of the class described in Wood's Specification No. 4175 of 1891 and in Pauzettas
Specification No. 20970 of 1893.
In the accompanying drawings:-
Figures 1 and 2 show two forms of thin metal band for stiffening the edges of
a tyre cover.
Figures 3, 4, 5 and 6 show in plan and cross sections portions of the non slip-
ping tyre tread.
Figures 7 and 8 are longitudinal sections of a Pauzetta valve, and
Figure 9 is an exterior view of the air plug of a Wood valve, commonly known
as the Dunlop.'
In carrying out the first part of the invention, the stiffening of the tyre cover
edges is effected by enclosing in or attaching to them, a continuous band of fret-
work made of thin sheet metal. The band is formed by taking a length of sheet
metal about in. wide and punching out gaps or spaces about in. wide extending
nearly across the band from each edge alternately, so that the remaining metal is
a fretwork of zig-zag form, as shown in Figures 1 and 2, possessing sufficient
longitudinal flexibility and transverse stiffness for the intended purpose of form-
ing a continuous hooked edge along each side of the cover.
The outer surface of the tyre has a pattern of ridges and hollows formed by
dividing the tread into two or more longitudinal strips H as shown in Figures 3
and 5. The surface of each strip has a rocking or tilting curvature from side
to side, proceeding along the tyre and the surfaces are parallel at corresponding
points of adjacent strips. In Figure 3 the rocks or tilts are all of equal length
whilst in Figure 5 they are alternately long and short.
In Figure 3 the distance A E is the length of tread occupied by one rock or
tilt of the surfaces from one side to the other and Figure 4 shows the cross-sections

page_text: at five places in the tilt by corresponding letters. Similarly in Figure 5 the
distance K represents the length of a rock or tilt and Figure 6 gives the cross-
sections at five places by corresponding letters. The thickened lines in Figures 3
and 5 indicate shadows cast by the edges of the strips by rays of light falling
thereon in the direction of the arrow shown.
Instead of running the strips straight along the tread, they may be laterally
waved or meandered across the tread in addition to having their surfaces tilted
as described.
In carrying out the improvements relating to air valves, for pneumatic tyres,
of the class before mentioned, sharp ridges or rings are formed upon the metal
valve tube, either externally or internally according to the construction of valve.
The rubber tubing which forms the valve is pressed upon these ridges by the
back pressure of the air, which prevents leakage along the minute furrow formed
where the tube is, joined longitudinally in process of manufacture. Figures 7, 8
and 9 are examples of the application of this device.
Figure 7 is a longitudinal section of a Pauzetta' valve furnished with four
internal ridges, the rubber tube being shown in dotted lines, and Figure 9 is an
exterior view of the air plug of the well-known Wood' valve furnished with
four external ridges, situated between the central hole and the end of the plug.
To prevent risk of the rubber tube in a 'Pauzetta' valve being blown out of
its place by forcible pumping the retaining pin L, Figure 7, is formed of hard
metal, such as German silver, and before being driven into its place longitudinal
burrs or ridges are formed on it which take forcible hold of the rubber. To
prevent the outer end of the rubber tube expanding into a head and choking the
entrance to the air passage an extra pin M may be employed as shown or the
two pins may be replaced by a slip of thin metal as at N Figure 8, the slip being
roughened or burred to retain the rubber.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I wish it to be under-
stood that I am aware of Letters Patent 21,989 of 1891 and No. 15163 of 1892
both granted to S. H. Stubbs and of Letters Patent No. 4813 of 1895 granted to
W. E. Crowther and that I claim nothing described and claimed in the Specifica-
tions of said Letters Patent, and I declare that what I claim is:-
1. For stiffening the edge of a pneumatic tyre cover the use of a metal band of
fretwork substantially as herein described, and illustrated in Figures 1 and 2
of the accompanying drawings.
2. A non-slipping tread for a pneumatic tyre formed by dividing the tread into
two or more parallel strips, the surfaces of which have a tilting curvature from
side to side proceeding along the tread, substantially as described.
3. The non-slipping tread for a pneumatic tyre described herein and illustrated
in Figures 3, 4, 5 and 6, of the accompanying drawings.
4. In an inflation valve furnished with an interior tubular rubber lining,
forming one or more annular ridges on the surface of the metal seat of the said
lining substantially as and for the purpose described herein and illustrated in
Figure 7 of the accompanying drawings.
5. In an inflation valve having an external tubular rubber sleeve, forming one
or more annular ridges on the surface of the metal seat between the air hole and
its end, substantially as and for the purpose described herein and illustrated in
Figure 9 of the accompanying drawings.
6. In an inflation valve having an internal lining secured by a pin, the use of
a second pin substantially as and for the purpose described.
7. In an inflation valve having an interior rubber lining, securing the said
lining by a flat strip or slip substantially as and for the purpose described.
8. In an inflation valve having an interior rubber lining, securing the said

page_text: lining by a roughened pin or slip of metal substantially as described herein and
illustrated in the accompanying drawings.
Dated this 10th day of January 1898.
WILLIAM EDWARD CROWTHER.
Applicant.