Improvements in Pneumatic Tyres, and in Pumps for Inflating the same.
Year: 1897

page_text: Date of Application, 25th Feb., 1897-Accepted, 12th June, 1897
COMPLETE SPECIFICATION.
Improvements in Pneumatic Tyres, and in Pumps for Inflating
the same.
1, WILLIAM BRETT WORGER of 27, Albert Grove, Southsea, Commercial
Traveller, do hereby declare the nature of my said 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 improvements in connection with pneumatic tyres and
to pumps for use with same, and has for its object to provide a means by which the
tyres may be automatically inflated on their becoming slack.
According to one part of my invention I fix an air cylinder provided with a
piston to the rim of the wheel. The piston is kept down to its normal position by
means of a spiral spring and is provided with a piston rod which extends into the
pneumatic tyre. The lower end of the said rod is provided with a shoe or
cross piece whose under surface is curved to a radius corresponding with the
tread of the tyre and which in its normal condition is about one quarter of an inch
from the inner surface of the tyre. The cylinder is provided at its upper end with
an air inlet valve and also with an outlet valve in connection with a vertical pipe
opening into the pneumatic tyre. As the tyre becomes slack it assumes a flattened
shape on its under side in contact with the ground, and thus bears against the
under surface of the shoe connected to the piston whereby the latter is raised and
forces the air above it through the vertical pipe into the pneumatic tyre.
When the pressure is released from the shoe as the wheel revolves, the piston is
again forced down by the spiral spring, and the shoe is again acted upon by the
pressure of the tyre, as it assumes its former or lowest position, to force a fresh
amount of air into the tyre, and this action continues until the tyre is fully inflated
when the latter ceases to act upon the valve or piston. I prefer to provide
the tyre with a small safety valve to prevent its becoming too tight or unduly
inflated.
According to a slight modification the motion given to the piston or inflator may
be greatly increased by a lazy tongs arrangement. According to this modification
the end of the piston rod is provided with a cross piece connected to the lazy tongs
fitted at each side of the piston. Each lazy tongs is provided with a foot at its
lower end which can touch the ground as the tyre is compressed. The small
motion given by the foot is considerably magnified by the lazy tongs which pull the
piston rod down and force air into the tyre.
According to another modification, the arrangement for the automatic air supply
may be contained within the tyre itself. Within the tyre a number of pumps is
placed consisting of rubber or other bags, which can be pressed between the
ground and the rim. These pumps are placed at regular intervals and are pre-
ferably arranged in pairs connected together by a suitable tube provided with a non
return valve. The air can be forced from one of these pumps into the second, and
as the wheel turns the compressed air from the second will be forced into the body
of the tyre until the pressure becomes sufficiently high. The first pump is provided
with an inlet which preferably passes through the rim of the wheel, and is also
provided with a non return valve allowing the air to pass in but preventing it
escaping.

page_text: In order that the invention may be more clearly understood, reference is had to
the accompanying sheet of drawings, in which
Figs. 1 and 2 are sections of a pump constructed according to my invention fitted
to a tyre, the views being taken at right angles to each other,
Figs. 3 and 4 are respectively an elevation and a section of a modification,
and Fig. 5 shows a second modification.
Referring to Figs. 1 and 2 A is the rim of the wheel to which the tyre B is
fitted, the rim and tyre being of any ordinary construction. To the inner side of the
frame the cylinder C is fitted carrying the piston D. This piston is carried on
the end of the piston rod d which is furnished with a foot d¹ formed according to
the inside of the tyre. When this foot is pressed in by the ground in the manner
above described, the piston D will be raised pressing the air into the upper part of
the cylinder. The compressed air passes through the tube E at the side of the
cylinder, this tube passing through the rim and opening into the tyre.
A non
return valve e is placed at the upper end of this tube or in any convenient position
allowing air to be forced into the tyre but preventing it escaping. The spring c is
placed within the upper part of the cylinder and bears upon the piston, causing it
to return to its normal position when released as the wheel travels round. To
prevent any danger of the air pressure in the tyre becoming too great, the rim is
fitted with the safety valve F allowing the air to escape when a certain pressure
has been reached.
The arrangement shown in Figs. 3 and 4 is of a somewhat similar type to the
construction already described, but instead of the piston D' being pressed upwards
pressing air into the top of the cylinder, the action is reversed and the piston rod
moved from the upper end. The spring c¹ is placed in the lower part of the
cylinder instead of at top. The piston rod d is furnished with the cross arm d² at
its upper end, to each end of which the lazy tongs G is fitted. The lower pivot of
the lazy tongs is at g.
Instead of the piston rod being provided with a foot by which the piston is
worked, each lazy tongs is furnished with the foot g', this foot being placed outside
the tyre and extending to within a short distance of the periphery. When the
tyre meets the ground at this point and is partially compressed, if it yields
sufficiently far the feet gl will also touch and any motion given to them will be
considerably magnified by the lazy tongs pulling down the piston and pressing air
into the lower part of the cylinder. The air then passes through the non return
valve el into the tyre.
As shown in Fig. 5 the tyre B is provided with a series of pumps H and H
placed in pairs which may extend completely round the tyre. These pumps are in
the form of bags of rubber or similar material, and the two pumps of each pair are
connected together by the tube h having the non return valve h', allowing air to
pass from H into H³, but preventing any return. The end of the pump H is
provided with the tube J also having a non-return valve j, this tube passing
through the rim allowing air to be drawn from the atmosphere into the pump.
The further end of the pump H' is provided with the tube K having a non-
return valve this tube opening into the tyre. The action of these pumps is as
follows,-
On being pressed between the ground and rim the pumps will be partially
collapsed successively, so that air will be forced from H into H' and thence as the
wheel turns through the opening into the tyre. When the pressure on the pumps
is released they will expand and air will be drawn from the atmosphere, which on
the pumps being again compressed will be forced into the tyre.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is.―
(1) An improved automatic pumping device for tyres, consisting of a pump
connected with the tyre. having a miston furnished with a proiecting foot adanted.

page_text: to be operated by pressing on the ground forcing air from the pump through a.
passage in the tyre, substantially as described and for the purposes specified.
(2) In an air pumping device for tyres, the combination with a cylinder fitted to
the rim of the wheel, a passage from the said cylinder to the tyre and a piston
collapsed in the said cylinder, of a foot connected to the piston rod and extending.
within the tyre adapted to operate the pump as the tyre is pressed on touching the
ground, substantially as and for the purposes specified.
(3) In an automatic pumping device for tyres, the combination with a cylinder
on the rim, a passage from the said cylinder to the tyre, a piston within the
cylinder, and spring bearing upon the piston, of a foot fitted to the piston rod, and
extending within the tyre, constructed and operating substantially as described and.
shown in Figs. 1 and 2 of the accompanying drawings, and for the purposes
specified.
(4) In an automatic pumping device for tyres, the combination with a cylinder.
on the rim, passage with valve leading from the said cylinder to the tyre, and a
piston within the cylinder, of lazy tongs fitted at the side of the tyre and connected
to the piston rod, and a foot adapted to meet the ground when the tyre is compressed,
substantially as described and for the purposes specified.
(5) The automatic pumping device for tyres the combination with a cylinder on
the rim, of a passage with valve leading from the said cylinder to the tyre, and
piston within the cylinder of a cross arm at the top of the piston rod, a lazy tongs.
fitted to each end of the cross piece and extending at each side of the cylinder, and
a foot at the lower end of each lazy tongs adapted to meet the ground when the-
tyre is compressed, substantially as described and shown in Figs. 3 and 4 of the
accompanying drawings, and for the purposes specified.
(6) An improved automatic pumping device for tyres, consisting of a series of
collapsible bags placed within the tyre, tubes connecting the said bags to the
atmosphere, connections between the bag and openings in the tyre all fitted with
non return valves, substantially as and for the purposes specified.
(7) The improved automatic pumping device for tyres, consisting of a series of
collapsible bags placed within the tyre, and arranged in sets of two tubes connecting
the two parts of each pair together, a tube or opening from the rear bag to the
atmosphere, a second opening from the front bag into the tyre, and a non return
valve fitted to each tube or passage, substantially as described and shown in Fig. 5.
of the accompanying drawings and for the purposes specified.
Dated this 22nd day of February 1897.
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.