Apparatus for flatproofing tires

Flatproofing liquid is provided to tires through a one-way disposable valve assembly. In accordance with the method, the valve stem core is removed from the tire to allow the liquid to be freely admitted. A one-way valve is attached to the valve stem, and the tire is filled with the flatproofing material. The flatproofing material is then allowed to cure in the tire and in the valve. After curing, the valve is removed and discarded. The apparatus includes an inexpensive one-way valve for connection to the valve stem at one end and supply hoses at the other.

FIELD OF THE INVENTION 
This invention relates to the art of method and apparatus for flatproofing 
tires. 
BACKGROUND OF THE INVENTION 
Tires on industrial equipment are constantly exposed to sharp objects, 
including metal, glass, thorns, and rocks, making them the most vulnerable 
part of such equipment. Consequently, flat tires are a common cause for 
equipment down time. 
In response to these problems, a number of methods have been developed to 
flatproof tires. One such method replaces the air in a tire with 
polyurethane, neoprene, or other suitable polymeric materials. The 
polymeric materials may either be dry filled into the tire as solid 
particles, or may be liquid filled into the tire as a mixture of reactants 
which cures over time into a solid polymeric mass. 
In the liquid fill method, the valve stem core is removed from the valve 
stem of the tire, and the tire is deflated to atmospheric pressure. A 
device for pressure filling the tire is then attached to the valve stem 
for filling the tire with liquid reactants. As the tire fills with the 
liquid, air in the tire rises to the top of the tire and is allowed to 
escape through a suitable perforation in the tire casing. When the tire is 
completely filled with liquid, as indicated by the emission of liquid from 
the perforation, the flow of liquid into the tire is stopped and the 
perforation blocked. Then, additional liquid is added until a desired 
pressure is achieved. 
Because the valve stem core has been removed from the valve stem to allow 
introduction of the liquid reactants, it is necessary upon completion of 
filling to block the valve stem while the polymeric mixture in the tire is 
curing. Presently, this is accomplished by replacing the valve stem core 
after the tire has been filled. The tool commonly used for this purpose 
has a barrel that fits over the valve stem at one end. The other end of 
the barrel is connected to hoses that supply the liquid reactants to the 
tire. A syringe-like device extends through the center of the barrel and 
has a plunger upon which the replacement valve stem core is mounted. In 
use, the plunger is carefully manipulated inward until the replacement 
valve stem core is aligned with the threaded surface on the interior of 
the valve stem. The plunger is then twisted to screw the valve stem core 
into place in the valve stem. 
This prior method, thus requires one to follow for each tire the steps of 
(1) removing the valve stem core, (2) attaching the barrel, (3) filling 
the tire, (4) replacing the valve stem core while the liquid polymer 
pressure is maintained, and (5) detaching the barrel. After this is 
accomplished for one tire, the worker moves to the next tire and repeats 
the same steps. With regard to step (4), it should be remembered that the 
valve stem is very small, and properly aligning the replacement valve stem 
core with the threaded surface in the valve stem is cumbersome and time 
consuming in practice, thus contributing to the high cost of flatproofing. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, tires are filled with the aid of 
a disposable one-way valve. The operation of a one-way valve per se is 
known in the art, but the particular housing for the valve used in 
accordance with the invention is adapted to be attached to a valve stem at 
one end and to supply hoses at the other. 
Prior to using the device of the present invention to fill a tire, air is 
released from the tire by removing the valve stem core of the tire. Thus, 
the interior of the tire is allowed to reach atmospheric pressure. Next, 
the one-way valve housing of the invention is connected to the valve stem 
by means of a threaded hole that matches the size of the valve stem. Then 
the other end of the valve housing is attached to a hose assembly 
connected to a supply of liquid fill reagents. 
The liquid fill reagents are passed through the tube assembly, through the 
valve housing, and into the tire. As the tire fills with the liquid 
reactants, air remaining in the tire rises to the top of the tire, where 
it is allowed to escape through a suitable perforation made in the tire 
casing. When the tire is completely filled, as indicated by the emission 
of liquid from the perforation, the flow of liquid into the tire is 
stopped. The perforation is then blocked, as by a screw, and additional 
liquid is added until the desired pressure is attained. 
After the flow of liquid through the delivery tube has been stopped, the 
outward pressure of fluid within the tire causes the one-way valve to 
close to prevent flow of fluid back into the supply hoses. The supply hose 
is then detached from the valve housing, and the polymer in the tire, the 
valve stem, and the valve housing is allowed to cure into a hardened 
polymeric mass. While the polymer cures, the worker applies another 
one-way valve housing to a subsequent tire and repeats the above process. 
After curing is substantially complete, the valve housings are disengaged 
from the tires and discarded. 
Thus, according to the invention, tires are filled with flatproofing 
material by (1) removing the valve stem core, (2) attaching the one-way 
valve assembly, (3) filling the tire, and (4) discarding the valve after 
cure. 
It is thus an object of the present invention to provide an easy, 
economical method of flatproofing a tire. 
It is a further object of this invention to provide a device that will 
effect the flatproofing of a tire in an easy, economical fashion. 
It is a further object of the present invention to provide an economical, 
easy to use, pressure resistant means for stopping the valve stem of a 
tire after flatproofing the tire with liquid reactants.

DETAILED DESCRIPTION OF THE INVENTION 
With reference FIG. 1 of the drawings, a device in accordance with the 
invention comprises a valve 2 attached to a known valve stem 4 at one end 
and to a hose assembly 6 at the other end. The hose assembly carries the 
liquid reagents used in the liquid fill method to a tire (not shown) 
having the valve stem 4, which is to be filled. The hose assembly 6 is 
equipped at one end with a female quick disconnect connector 8, which is 
capable of being easily attached to or detached from the valve 2. The 
other end of the hose assembly includes a threaded pipe connector for 
interfacing with a source of the liquid reactants for filling the tire. 
The pipe connector is threaded may have an inner diameter of about 7/8". 
The hose 12 of the hose assembly 6 is preferably made of flexible, 
pressure resistant material, such as reinforced rubber. The interior of 
the hose may be coated with Teflon or similar materials which are 
resistant to the chemicals used in flatproofing tires. 
FIG. 2 illustrates.the components of the valve assembly of the present 
invention. The valve assembly comprises a housing 14 having a threaded 
opening 16 at one end for receiving the threaded end 18 of the tire valve 
stem 4. The other end of the housing receives a male adaptor that closes 
the housing to form a sealed unit. The male adaptor and housing are shown 
as having a threaded connection, but these parts may as well be cemented 
together for ease of manufacture. A moveable valve element 22 fits into 
the housing and includes a first valve seat surface 24 that cooperates 
with a second valve seat surface 26 on the male adaptor to prevent flow 
back into the hose 12 when the pressure in the tire exceeds that in the 
hose, in accordance with the known operation of a oneway valve. Likewise, 
when the pressure in the hose exceeds that in the tire, the valve element 
22 is forced away from the seat 26 to allow liquid to flow through the 
housing. Grooves 28 are provided in the valve element 22 to facilitate 
flow of material around the valve element. 
The upstream end of the male adaptor 20 includes a quick disconnect 
connector 30 for interfacing with the quick disconnect 8 of the delivery 
tube. 
As is known in the art, the quick disconnect 8 includes a slidable, spring 
driven outer sleeve that fits over the connection 30. The quick disconnect 
is fitted with a series of perforations in the immediate vicinity of its 
lip. These perforations house ball bearings which are freely movable 
within the perforations when the sleeve is withdrawn against the spring. 
When the sleeve is released, the spring forces the ball bearings to 
protrude into the interior of the inner annulus, where they engage the lip 
of the male adaptor 20. 
The male adaptor 20 is roughly cylindrical in shape and is fitted on one 
end with an annular lip 32 for cooperation with the quick disconnect 8. 
The entire valve assembly 2 is designed for disposal after each use, and is 
therefore made of inexpensive but durable materials. Preferably, the male 
and female adaptor are made of a clear or opaque plastic, such as 
polyethylene or polyacrylate, which allows the user to observe the flow of 
liquid therein. The valve may be made of materials similar to those used 
for the male and female adaptor. However, it is preferred that the valve 
be made of a low friction plastic or polymer, such as Teflon or a similar 
polyfluoroethylene. It is also preferred that the valve material 
incorporate a carbon black filler or similar pigment to render it more 
visible when it is inside the female adaptor. 
It will be appreciated that a unique method and apparatus for flatproofing 
tires have been described. Modifications within the scope of the appended 
claims will be apparent to those skilled in the art.