Improvements in the Means for Securing the Outer Covers of Pneumatic Tyres to the Rims of Wheels of Cycles and other Vehicles.
Year: 1892

page_text: · Date of Application, 9th Dec., 1892
Complete Specification Left, 7th Oct., 1893-Accepted, 11th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Means for Securing the Outer Covers of
Pneumatic Tyres to the Rims of Wheels of Cycles and other
Vehicles.
JOHN MACKENZIE of Egglescliffe, Yarm-on-Tees Engineer do hereby declare
the nature of this invention to be as follows:-
The object of this invention is to provide a simple and efficient means for
securing the outer covers of pneumatic tyres to the rims of cycles and other
vehicles, which will enable the covers to be detached from the rims at will, with
ease. For this purpose I construct the outer covers of pneumatic tyres in a special
way, preferably with a bulb or swelling on the two inner edges, where the cover
joins the rim. I construct the rim with a recess or curve to receive this bulb or
swelling.
I place round the circumference of the rim a metallic or other band, which is
not joined, but which, when drawn tightly, nearly meets at the ends. On the ends
of this band I fix lugs which pass through suitable slots in the rim, the lugs are
provided with suitable means for opening and closing, so that the band can be
drawn tight on the rim or loosened at will.
To fasten the cover of the tyre, I loosen the band, and place the bulbed edges of
the cover, between the band, and the rim, and draw the band tight by means of the
lugs attached to the ends of the bands. To take the cover off, I loosen the band
It is not
and draw the bulbed edges out from between the band and the rim.
essential that the band should be in one piece as described above, but it may be in
two or more pieces and secured by bolts passing through the rim.
Dated this 8th day of December 1892.
JOHN MACKENZΠΕ,
COMPLETE SPECIFICATION.
Improvements in the Means for Securing the Outer Covers of
Pneumatic Tyres to the Rims of Wheels of Cycles and other
Vehicles.
I, JOHN MACKENZIE, of Egglescliffe, Yarm-on-Tees, in the County of Durham,
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 :-
My invention is connected with pneumatic tyres particularly for use in cycles.
and has for its object to provide a simple and efficient means for securing the outer
detachable cover to the main rim with a view of enabling the said outer cover to
be easily and expeditiously detached from the said rim for inspecting and repairing
the air tube within or to be refixed and secured in position so as to be forthwith
ready for further use.
The main feature of my invention consists in the particular construction and
means for contracting and clamping an open hoop or band as shown in the drawings
annexed to this Specification which hoop or band embraces preferably in one
continuous length the full periphery of the cycle wheel rim with the edges of the
outer cover inserted or sandwiched between the main rim and the clamping hoop or
band it being essential that the said clamping hoop or band terminate end wise in
lugs or tie rods extending through the main rim by which the contracting strain on

page_text: :
the clamping hoop is applied as nearly in the tangential direction to the circle
of the hoop as the internal curvature of the fixed or main rim admits of, otherwise
the said hoop or band cannot be drawn tight in a manner adapted to secure the
outer cover tight onto the main rim at all parts of their common circumference.
I am aware that the contraction of a clamping hoop or band has been suggested
as a suitable way of securing the outer cover of a pneumatic tyre to the rim of the
wheel and the improvements constituting my invention are based on the observation
that unless provision is made for applying the contracting strain in an approximately
tangential direction to the circle of the clamping hoop or band the requisite
contraction of this hoop or band will not be attained.
In the drawings annexed to this Specification which are intended to illustrate
those modifications of my invention which are thought to be most serviceable for
ordinary use and are at the same time sufficient for the purpose of fully explaining
my invention,
Figures 1 and 3 are inner circle segmental views of the tyre as fixed in position
upon the rim of the cycle wheel when ready for use
Figures 2 and 4 being corresponding sectional views taken on line x x of Figure 1
and line y y of Figure 3, respectively. A is the outer cover or sheath and B is the
air tube; C is the main rim of the wheel and D is the clamping hoop or band for
securing the outer cover A to the rim C which hoop or band terminates end wise in
lugs in Figures 1 and 2 and in tie rods in Figures 3 and 4 by which it is contracted
or relaxed as required.
In Figures 1 and 2 where lugs E are shown, F is the adjusting screw by which
the lugs E are forced together in contracting the hoop D on the main rim C or are
allowed to recede from each other when relaxing the hoop to release and remove
the outer cover A the edges of which are bulbed or thickened up at the part which
is inserted or sandwiched between the rims C and D the advantage of which is
obvious.
To ensure that a tangential strain is transmitted by the lugs E E to the clamping
hoop D when forced together by screwing up the nut H on the bolt F the main
rim is set to an incline along each slot so that the shoulders of the lugs E E
work each on an inclined seat by which a radial pull is brought to bear on the
clamping rim and the tendency of the lugs E E to spring the said ends of the
clamping rim outwards or upwards is prevented. In Figures 3 and 4 the tie
rods E E¹ take the place of the lugs E and their adjusting screw F each tie rod E¹
being inserted through a tubular sleeve G against the outer ends of which the
nuts H' find the requisite bearing for screwing up the clamping hoop D or relaxing
it in the manner required.
The effect of screwing up or unscrewing the nuts H' in this case is too obvious
to require explanation the essential condition that the strain applied by their means
to the clamping rim D shall take a direction as nearly tangential to the circle of
the clamping hoop as the internal curvature of the rim admits being clearly
complied with.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:―
Firstly. In a pneumatic tyre in which the inner tube B and outer cover A are
attached or secured to the wheel rim C by a clamping rim D the combination with
the clamping rin, or hoop of the lugs E E with shoulders working on inclined seats
along the slots C' whereby a contracting strain can be applied to the said clamping
rim or hoop by means of screw F, substantially as and for the purpose as herein-
before described with reference to Figures 1 and 2 of the accompanying drawing.
Secondly. In a pneumatic tyre in which the inner tube B and outer cover A are
attached or secured to the wheel rim C by a clamping rim D the combination with
the said clamping rim or hoop of the tie rods El passing through sleeves G on the
main rim C the ends of which afford bearings to the nuts H' whereby a contracting

page_text: strain can be applied to the said clamping rim or hoop substantially as and for the
purpose as hereinbefore described with reference to Figures 3 and 4 of the:
accompanying drawing.
كيم
.
1000
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.