Improvements in Wheels with Pneumatic Tyres.
Year: 1891

page_text: Date of Application, 17th Aug. 1891
Complete Specification Left, 26'h Aug., 1891-Accepted, 31st Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in Wheels with Pneumatic Tyres.
I, KARL LEHMANN of Winterfeldstrasse, 5/6. I, Berlin, W., Law Student, do
hereby declare the nature of this invention to be as follows:-
Wheels as heretofore constructed with pneumatic tyres, have the drawback that
the air tubes frequently burst as the result of excessive compression; and the
removal of the tyre, as also of the protective rubber from the wheel rim for the
purpose of repair, is attended by great difficulty and inconvenience. Furthermore
the usual mode of attaching or securing the air tube or protective india rubber ring
tends to speedy destruction of the same.
Now this invention has reference to a construction of wheel rim with pneumatic
tyre designed to obviate these disadvantages, as I will proceed to explain by aid of
the accompanying drawings in which
Fig. 1 is a section through the wheel rim and pneumatic tyre drawn full size;
Fig. 2 is a side elevation of a part of the wheel; and
Fig. 3 shews separately in section a protective india rubber ring.
The wheel rim a is made of steel of approximately semi-circular form in cross
section with inwardly extending or projecting annular portions a', and with outwardly
extending annular side portions all these latter portions being formed in such a
manner as to be capable of serving to retain in place and to form an abutment for
the protective india rubber ring b. d is the air tube to contain compressed air. It
consists of the finest india rubber of about 2 m/m thickness, and in cross section is
of circular form as shewn, but bellied or curved inward at opposite sides. The sides
and outer periphery of this tube are surrounded by the protective india rubber
ring 6 as shewn in Fig. 3. The ring & forms in cross section, an incomplete or open
ring with grooves kk into which fit the annular portions a' a' of the steel rim a.
Within it and on the side that comes in contact with the ground is embedded a
strong fabric c which prevents the ring 6 from being completely cut through by
sharp objects, as for example broken glass, lying on the ground ridden over.
At the inner side of the air tube where the heads of the spokes connected to the
steel rim a would meet the air tube, and injure the same, there is provided an elastic
protective ring i which surrounds the said air tube and upon which the heads of the
spokes press.
upon
When the air tube and protective india rubber ring constructed as described have
been placed in position upon the wheel rim and compressed air is forced into the air
tube through the air-charging valve e, the air tube d will become expanded and will
in consequence press the protective ring & in an outwardly inclined direction the
inwardly extending portions a' of the steel rim a. The protective ring will thus be
rigidly fixed in the position shewn in Fig. 1, and bursting of the air tube, in conse-
quence of excessive load or jolting of the wheel will be obviated by the rim which
extends over half the diameter of the pneumatic tyre and in this manner limits the
compression of the air tube to a determined extent. The protective ring & bears
laterally against the outwardly bent portions all of the steel rim which thus limits
the lateral bulging or expansion of this ring. The cutting and consequent spoiling
of the protective ring, when the same expands laterally in consequence of the load
thereon, is thus completely obviated, since, as will be readily seen from Fig. 1, the
steel rim has no sharp edges.
To remove the protective ring b for the purpose of repair it is meraly necessary

page_text: to allow the compressed air to escape from the tube d, whereupon the protective
ring can be readily removed from the wheel rim.
Dated this 17th of A 1001
K. LEHMANN,
By L. W., per F. B.
COMPLETE SPECIFICATION:
Improvements in Wheels with Pneumatic Tyres.
I, KARL LEHMANN of Winterfeldstrasse, 5/6 I, Berlin, W. Law Student, 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 :-
Wheels as heretofore constructed with pneumatic tyres, have the drawback
that the air tubes frequently burst as the result of excessive compression;
and the removal of the air tube and also of the protective india rubber ring
from the wheel rim for the purpose of repair, can be effected only with great
difficulty and inconvenience. Furthermore the usual mode of attaching or securing
the air tube or the protective india rubber ring tends to speedy destruction of the
same.
Now this invention has reference to a construction of wheel rim with pneumatic
tyre designed to obviate these disadvantages, as I will proceed to explain by aid of
the drawings left with my Provisional Specification in which
Fig. 1 is a section through the wheel rim and pneumatic tyre, drawn full size;
Fig. 2 is a side elevation of a part of the wheel; and
Fig. 3 shews separately in cross section a protective india rubber ring.
The wheel rim a is made of steel of approximately semi-circular form in cross
section with inwardly extending or projecting annular portions a', and with out-
wardly extending annular side portions a", these latter portions being formed in
such a manner as to be capable of retaining in place and forming an abutment for
the protective india rubber ring b. d is the air tube to contain compressed air. It
consists of the finest india-rubber of about 2 m/m thickness, and in cross section is
of circular form as shewn, but bellied or curved inward at opposite sides. The
sides and outer periphery of this tube are surrounded by the protective india rubber
ring b as shewn in Fig. 3. This ring b forms in cross section, an incomplete or open
ring with annular grooves k, into which fit the annular portions a¹ a¹ of the steel
Within it and on the side that comes in contact with the ground is embedded
or moulded an annular strip c of woven material such as canvas, which prevents the
ring from being completely cut through by sharp objects, as for example broken
glass, lying on the ground ridden over.
rim a.
At the inner side of the air tube, where the heads of the spokes connected
to the steel rim a would meet the air tube, and injure the same, there is provided
an elastic protective ring of suitable material such as india-rubber which surrounds
the said rim and upon which the heads of the spokes press.
When the air tube in an uninflated condition and the protective india rubber ring
constructed as described, have been placed in position upon the wheel rim and
compressed air is forced into the air tube through the air charging valve e, the air
tube d will be expanded and will in consequence press the protective ring in an
outwardly and inclined direction upon the inwardly extending portions a¹ of the
steel rim a. The protective ring will thus be rigidly fixed' in the position, shewn
in Fig. 1, and bursting of the air tube, in consequence of excessive load or
jolting of the wheel will be obviated by the rim which extends over half the
diameter of the pneumatic tyre and in this manner limits the compression of the
air tube to a determined and safe extent. The protective ring bears laterally
against the outwardly. bent portions a¹¹ of the steel rim which thus limits the
lateral bulging or expansion of this ring. The cutting and consequent spoiling

page_text: of the protective ring, when the same expands laterally in consequence of the
load thereon, is thus completely obviated, since, as will be readily seen from
Fig. 1, the steel rim has no sharp edges.
To remove the protective ring b for the purpose of repair it is merely necessary
to allow the compressed air to escape from the tube d, whereupon the protective
ring can be readily removed from the wheel rim.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. A wheel having a rim of approximately semi-circular shape in cross section
with inwardly extending projections a' a¹, and laterally and outwardly extending
side portions or flanges all, and a pneumatic tyre comprising an air tube d of
circular cross section but curved inwards at opposite sides, and an outer pro-
tective indin rubber ring formed with annular grooves kk, the arrangement
being such that when the air tube is charged with compressed air, the protective
ring will be expanded and be firmly held to the wheel rim by the projec-
tions a a¹ which will enter the grooves kk', whilst the flanges a² of the rim
constitute an abutment for the protective ring b, and serve to prevent excessive
compression of the air tube, substantially as hereinbefore described for the
purpose specified.
2. For a wheel having a rim of the cross section referred to in the preceding
claim, a pneumatic tyre comprising an air tube a and an outer protective india
rubber ring b, each having a cross section substantially as described and shewn
for the purpose mentioned, whether or not the ring b be provided with an
embedded annular strip c of woven material as set forth.
Dated this 26th dox of Avant 1901
K. LEHMANN,
By L. W., per F. B.