An Improved Instrument for Use in Detaching Pneumatic Tyres.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
An Improved Instrument for Use in Detaching Pneumatic Tyres.
I, JOZUA CORNELIS HENDRIKUS VAN DUYL, of Kralingsche-Veer, near
Rotterdam, in the Kingdom of the Netherlands, Engineer, do hereby declare the
nature of this invention to be as follows:-
This invention relates to an instrument for detaching pneumatic tyres from wheel-
rims and has for its object to enable the operation to be performed easily and without
rending, piercing or otherwise damaging the inner tube as is often done with the
instruments usually employed.
Until now all sorts of instuments, such as common nails, knives, spoons or like
pointed objects, have been used to detach the outer cover or sheath from the wheel-
rim of bicycles and the like, in case of puncture or other injury. As is well known
the tyre is pinched in a groove of the rim and the outer cover or sheath must be
forced out with a lever and stripped off all round the rim in order to be able to take
the tyre off. In doing so, the pointed instrument which is made use of, often tears,
pierces or otherwise injures the inner tube if such instrument slips through in forcing
it between the rim and the tyre, and in such case the damage becomes more serious
than the puncture to be repaired.
The present invention obviates all these inconveniences, and by means of the
improved instrument, the outer cover or sheath can be easily forced out and stripped
off, and the inner tube is not liable to be damaged or torn. The improved instrument
is also provided with a suitable device for loosening the outer cover or sheath or the
inside-tube if either should stick to the rim, and also for pushing the inner tube
inward if it is pinched between the rim and the wire of the outer cover or sheath in
applying the tyre again to the wheel.
In the simplest form of the improved instrument which is destined to be used by
workmen in bicycle manufactories and repair shops, a bar is pointed at one end and
there provided with a projection or heel set at about a right angle to the bar about
one inch from the point. This heel is about half-an-inch long. Now by inserting
the point of the bar between the wheel-rim and the wire of the outer cover or sheath,
the heel by bearing against the rim prevents the bar from slipping into the tyre and
thus damaging the inner tube, whilst the point cannot reach beyond the middle of the
wheel-rim. The inner tube being no more inflated will yield before the point of
the bar in stripping off the cover or sheath, but as the heel bears against the rim,
the point cannot slip entirely under the tyre, so that the inner tube cannot get torn
or pierced through.
The same pointed end'can also be used to loosen the cover or sheath from the rim
or to push the uninflated inner tube under the said cover or sheath if it should be
pinched between the wire of the cover and the wheel-rim.
For bicyclists I make a more convenient shape of the instrument which can be
easily carried in the pocket or in the saddle-bag or kit-bag.
It consists of a flat bar in the shape of a cross. On one of the four ends, the said
heel is provided, another end is pointed as well, but thinner in order to loosen the

page_text: tyre and to push the uninflated inner tube inward as before mentioned, whilst both
the other ends are provided one with a square nut-hole and the other with a screw-
driver point and are used to fasten the chain connecting screw and nut, or for other
purposes.
I, JOZUA CORNELIS HENDRIKUS VAN DUYL, of Kralingsche-Veer, near Rotterdam, in
the Kingdom of the Netherlands, 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:-
This invention relates to an instrument for detaching pneumatic tyres from wheel-
rims, and has for its object the provision of means to enable the operation to be
performed easily and without rending, piercing or otherwise damaging the inner tube
as is often done with the instruments such as are usually employed.
Until now all sorts of instruments, such as common nails, knives, spoons or like
pointed objects, have been used to detach the outer cover or sheath froin the wheel-
rim of bicycles and the like in case of puncture or other injury.
As is well known, the tyre is pinched in a groove of the rim and the outer cover
or sheath must be forced out with a lever and stripped off all round the rim when it
is required to take off the tyre from the wheel-rim. In so doing, the pointed
instruinent which is made use of, often tears, pierces or otherwise injures the inner
tube. If such an instrument slips in forcing it between the rim and the tyre, the
damage arising from such mishap may be more serious than the puncture to be
repaired.
The present invention obviates all these inconveniences, and by means of the
improved instrument the outer cover or sheath can be easily forced out and stripped
off and the inner tube is not liable to be damaged or torn. The improved instrument
is, moreover, in some instances, provided with a suitable device for loosening the
outer cover or sheath, or the inside tube, if either should stick to the rim, and also
for pushing the inner tube inward if it is pinched between the rim and the wire of the
outer cover or sheath on applying the tyre again to the wheel.
In the accompanying drawing I have shown how ny said invention may be
conveniently and advantageously carried into practice.
Figure 1 is an edge view, and
Figure 2 a side view of one form of my improved instrument.
Figure 3 is a side view, and
Figure 4 an edge view showing another form or modification of the same.
Like letters indicate corresponding parts throughout the drawing.
In the simplest form, as shown in Figures 1 and 2, the improved instrument is
suitable and is chiefly intended for use by workmen in cycle manufactories and
repairing shops. The bar A is somewhat flattened out at B, rounded at the end, and
ground down to a blunt edge. A projection or heel C about one-half of an inch long,
standing out at right angles from the bar A, is provided at about one inch, more or
less, from the extremity B, and by bearing against the wheel-rim prevents the
point B from penetrating too far into the tyre and thus damaging the inner tube,
or the point from reaching beyond the middle of the wheel-rin, when the point is
inserted between the wheel-rim and the wire of the outer cover or sheath.

page_text: When it is desired to remove the cover of a tyre, the contained air being allowed
to escape, the inner tube will yield before the point B of the bar in stripping off the
cover or sheath, but as the heel C bears against the rim, the point cannot slip
entirely under the tyre, so that the inner tube cannot by this operation get torn or
pierced through.
The same pointed end can also be used to loosen the cover or sheath from the rim
or to push the uninflated inner tube under the said cover or sheath if it should get
pinched between the wire of the cover and the wheel-rim.
For cyclists and others I make a modified and more convenient shape of the
instrument which can be easily carried in the pocket or in the saddle-bag or kit-bag.
As shown in Figures 3 and 4, this modified instrument consists of a flat bar in the
shape of a cross. One of the four arms A, is provided with a heel or projection C, to
act in co-operation with the point B as herein before described. Another arm D is
made substantially oval in cross-section and tapered off to a blunt point similar in
shape to, but thinner than the point B and adapted to loosen the tyre or to push the
uninflated inner tube inward, as above mentioned.
Other arms E and F are provided, one with a screw-driver point as at b, and the
other with a square nut-spanner as at a suitable for use in fastening or adjusting the
chain connecting-screw and nut, or for other purposes.
My improved instrument may be of metal, wood or suitable material.
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 :-
First. An instrument for use in detaching pneumatic tyres from wheel-rims'
provided with a blunt blade or end and with a heel or projection, substantially as,
and for the purposes, hereinbefore described.
Second. The combination, with my improved instrument, of other useful and
serviceable tools such as a screw-driver, a spanner or the like, substantially as, and
for the purposes, hereinbefore described.
Dated the 18th day of September 1897.
D. YOUNG & Co.,
11 and 12 Southampton Buildings, London, W.C., Agents for the Applicant.