This invention relates to tires for automobiles and other vehicles.
As is well known, automobiles and other vehicles currently rely on tires that are filled with air. Since air is compressible, the captive air in a tire obeys Boyle's law:
P×V=K
where P is the air pressure, V is interior volume of the tire, and K is a constant. It is assumed that temperature is held constant.
When a tire is initially inflated, the pressure is referred to as the “standing pressure.” Boyle's law becomes:
Ps×Vs=K
where Ps is the standing pressure and Vs is the volume of the tire with no load imposed on it.
When a load is imposed on the tire, the equation becomes:
P1×V1=K
where P1 is the pressure in the tire under the load, and V1 is the volume inside the loaded tire. Since P1 must be greater than Ps to support the load, it follows that
V1<Vs
In short, when a tire is filled with a compressible gas such as air, its volume decreases proportionately with the load on the tire. This volume reduction shows up mainly as a flat area where the tire meets the road. The tire is deformed. As a result of this deformation, a considerable amount of energy is required to roll the automobile or other vehicle. It is well known, for example, that the gas mileage of an automobile suffers when its tire pressure is reduced. While, conversely, the gas mileage may be improved by increasing the tire pressure, the energy “wasted” in deforming the tires can not be reduced to an acceptable level. Moreover, the flattening of the tire causes the rubber to rub against the road surface in a way that creates road noise, heat and increased tire wear.
Because air-filled tires are relatively light in comparison to the weight of the vehicle, the center of gravity of the vehicle is relatively high. This makes the vehicles susceptible to overturning on sharp curves. The tendency of sport utility vehicles (SUVs), in particular, to overturn has received considerable publicity in the media lately.
If an air-filled tire is punctured, it normally becomes flat in a short period of time and thus requires immediate attention. This can occur at very inopportune moments, such as when the car is being driven on a congested superhighway. Pulling the car onto the shoulder to change a tire can be very hazardous in such circumstances.
Air-filled tires can burst or explode when the car is driven over a pothole or speed bump, causing the driver to lose control of the car and putting the driver and other occupants of the car in extreme danger.
Air contains about 21% oxygen. Oxidation of rubber causes it to dry out and crack. Thus contact between the oxygen in air and the tire rubber reduces the strength and life of the tire.
These problems are largely overcome with a tire that is filled with water, using the apparatus and method of this invention. In this manner, a tire can be filled with water with only a minimal air residue remaining in the tire. This is difficult to accomplish because the main constituents of air (O2 and N2) are relatively insoluble in water. If an air pocket remains in the tire, the tire will not be balanced. An unbalanced tire will shake the vehicle when it is spinning.
According to the method of this invention, a tire is partially filled with water, trapping and compressing the air in the tire. The trapped air is released until the remaining air in the tire is at, for example, atmospheric pressure. A gas such as CO2 that is highly soluble in water is then introduced under pressure into the tire, creating a mixture of air and the water-soluble gas. The mixture is then vented to the atmosphere and an additional amount of the water-soluble gas is introduced into the tire under pressure. Again, the gases remaining in the tire are vented to the atmosphere.
This process is repeated several times. After each introduction of the water-soluble gas into the tire, the proportion of the water-soluble gas to air increases. For example, if CO2 is introduced into the tire at 6 atmospheres of pressure (88.2 psi) and the process is repeated three times, the gas remaining in the tire will consist of only 1/216 (1/63) air and 215/216 CO2.
Water, either pure water or another aqueous liquid such as water containing the water-soluble gas, is then introduced into the tire under pressure. The tire is then agitated, for example by spinning it, to dissolve all of the water-soluble gas in the water.
Additional water can then be added to increase the pressure in the tire to the desired standing pressure.
In an alternative method according to the invention, water containing a gas that is the gas is pumped out of the tire, leaving a near vacuum. Additional water containing the water-soluble gas is introduced into the tire, and the tire is agitated, for example by spinning, to dissolve any remaining gas. Additional water can then be added to increase the pressure in the tire to the desired standing pressure.
The water-filled tire of this invention largely overcomes the problems with air-filled tires described above. Since water is incompressible, the portion of the tire that is flattened against the road surface is greatly reduced. The amount of flattening is largely independent of the weight of the vehicle and its cargo. The greater mass of water as compared with air also increases the centrifugal force on the tire when it is spun, further reducing the flattening of the tire against the road surface. This effect becomes more pronounced as the speed of the vehicle is increased. Thus less energy is absorbed and wasted in deforming the tires as they roll on the road surface. Particularly on long trips, gas mileage is increased, saving fuel expense. Especially with the recent increases in the price of gasoline, this is an important factor. On shorter trips, it is believed that the increased energy required to move a heavier tire and the energy savings from reduced tire deformation generally offset each other. Moreover, because a water-filled tire weighs more that an air-filled tire, the vehicle will coast further when the gas pedal is released. The slight decrease in acceleration because of the greater weight of the tires does not affect safety appreciably and may in fact lead to safer driving habits. In fact, acceleration at high speeds is actually improved due to the centrifugal force effect described above.
In “stop and go” traffic, drivers can reduce energy consumption and brake pad wear by allowing more distance between the car in front of them and allowing their car to coast more.
The reduced flattening of the tires also reduces the stress on the steering system, particularly at higher speeds.
The increased weight of the tires lowers the center of gravity of the vehicle, lessening the tendency for it to overturn on sharp curves or at high speeds.
Using water instead of air to fill the tire increases tire lifetime since there is no oxygen in contact with the interior surfaces of the tire. Rubber has a moisture content of about 0.5%. Contact between the water and rubber preserves the moisture in the rubber. The tire will have a longer life and greater flexibility. The tire also tends to heat up less and makes less noise against the road. There is less rubbing between the tire and the road, and this also reduces the amount of wear on the tire.
Water leaks from a puncture in a tire at a rate up to 1,000 times slower than air. Thus the car can often be driven a considerable distance before repairs are necessary. It is rarely necessary to pull the car over immediately to change a tire. Moreover, leaks are easy to detect because water can be observed or the road or driveway surface. The tire needs to be filled only once a year or so, and only a small amount of water is required.
Water-filled tires have a higher dynamic coefficient of friction with the road than air-filled tires, decreasing the tendency of the tires to slide on the road surface. The vehicle will “hug the road” better and tilt less on sharp turns. Water-filled tires anchor the vehicle to the road better than air-filled tires. The vehicle stops well when braked.
Because water is incompressible, the tires will not burst or explode when driven over potholes and speed bumps. Moreover, the tendency of a vehicle with air-filled tires to oscillate up and down is eliminated.
The invention also comprises apparatus for performing the above methods. Apparatus for performing the first method comprises a gaseous water generator connected through a conduit to a connector for a tire valve stem. The conduit also includes a valve for controlling the flow of a gaseous water from the gaseous water generator to the connector. (Note that as used herein the term “gaseous water generator” refers to any device that operates to dissolve a water-soluble gas in water, whether or not the gas is CO2; the term “gaseous water” refers to water that contains a significant amount of a dissolved gas.)
Apparatus for performing the second method comprises a gaseous water generator connected through a first conduit to a connector for a tire valve stem and a vacuum pump connected through second conduit to the tire valve stem. The first conduit contains a first valve for controlling the flow of gaseous water to the tire valve stem; the second conduit contains a second valve for controlling a flow of gas from the connector to the vacuum pump. A portion of the first and second conduits may overlap.
According to another aspect, the invention also comprises a gaseous liquid generator. The gaseous liquid generator comprises a mixing block having a gas inlet, a liquid inlet and a liquid outlet. The gas inlet is connected through a first conduit to a source of pressurized water-soluble gas. The liquid inlet is connected through a second conduit to a source of pressurized liquid. The liquid outlet is connected through a third conduit to a pump, which is preferably a centrifugal pump but may be a piston pump or a rotary vane pump, for example. The first (gas) conduit may include a first valve such as a gas solenoid valve, a back flow valve and a gas flow regulator. The second (liquid) conduit may include a back flow valve and a flow regulator. The mixing block may have additional gas/liquid inlets if it is desired to produce a gaseous liquid that contains more than one liquid and/or dissolved gas.
In one embodiment, the mixing block includes a constricted portion of a water flow path. A gas flow path intersects the constricted portion of the water flow path. In another embodiment, the mixing block includes a small tube that is in flow communication with the gas inlet and that projects into an interior region of a water flow path.
According to yet another aspect of the invention, the gaseous water generator is used to produce aerated or carbonated or ozonated water by using air, carbon dioxide or ozone, respectively, as the pressurized water-soluble gas. Aerated or ozonated water has many uses in fish and shrimp farms and in other agricultural applications. Aerators and ozonators can also be used to purify water in sewerage plants. Carbonated or ozonated water can be used as a cleansing or germicidal agent for human hair and skin and for foodstuffs.
In some embodiments of this invention, the inlet of the centrifugal pump is used as the mixing block.
The invention will be better understood by reference to the following drawings.
In
The water may be injected into tire 10 with a piston pump, which can be a small as a home-use high pressure washer. The piston pump can provide a very homogeneous gaseous water solution with no separated gas bubbles in the water. Alternatively, a “Procon” rotary vane pump can be employed.
The water may initially be filled to a level above nozzle 12. When connector 18 is removed from nozzle 12, the water will drain out until its surface is level with nozzle 12. The trapped air above the water will be at a pressure of one atmosphere.
Next, as shown in
After the pressure in tire 10 has reached the desired level, three-way valve 22 is switched to allow the gas mixture within tire 10 to vent to the atmosphere, as shown in
The steps shown in
When the desired fraction of air in tire 10 has been reached, gas connector 24 is disconnected from nozzle 12 and water connector 18 is reconnected to nozzle 12. Pure water or gaseous water is injected into tire 10 until a desired pressure is reached. This step of the process is illustrated in
Next, as shown in
As shown in
The standing pressure should be at least high enough to prevent the dissolved gas from coming out of solution as tire 10 heats up during use. The required standing pressure depends on the solubility of CO2 in water and the temperature to which the tire will be heated in operation. For example, if CO2 is dissolved in water to 0.5 volume solubility, the nature's pressure of the CO2 at 160° F. is 30 psig. Therefore, if water is injected into tire 10 to a pressure of 30 psig, the CO2 will remain in solution when the tire is heated to 160° F. Normally, the temperature of water filled tires does not exceed about 160° F. in ambient temperatures up to 90° F.
To generalize this discussion, the amount of the water-soluble gas dissolved in the water will be (a) substantially greater (e.g., at least three (3) times greater) than the amount of the gas that occurs naturally in water that is exposed to the atmosphere and (b) less than the amount of the gas which would cause the nature's pressure of the gas at the maximum temperature to which the tire is expected to be heated to exceed the standing pressure of the water in the tire. Otherwise, if the amount of the water-soluble gas in the water is greater than the amount set forth in condition (b) above, the gas will separate from the water when the tire reaches the maximum temperature. As used herein the “nature's pressure” means the pressure that is required to suppress the gaseous water or the pressure that the gaseous water will show at a predetermined temperature and at a level of gas solubility in the water (or a level of “fizziness” of gaseous water).
The anparatus shown in
Initially, tire 10 is oriented such that nozzle 12 is at the top of the inner circumference of tire 10, and the air in tire 10 is released to a pressure of one atmosphere. A connector 30 is attached to nozzle 12. Connector 30 is connected via a line 32 to a three-way junction block 34. One inlet ofjunction block 34 is connected to a pressure gauge 36 and a valve 38 and via a line 40 to a pump 42. The inlet of pump 42 is connected to a source of gaseous water, for example, water containing dissolved CO2.
The other inlet of junction block 34 is connected via a line 44 to a vacuum pump 46. Line 44 contains a valve 48.
The method will now be described.
Valve 38 is opened and valve 48 is closed. Gaseous water having dissolved CO2 at, for example, 1.0 volume or less is injected into tire 10 until the surface of the gaseous water reaches the level of nozzle 12.
Valve 38 is closed, and connector 30 is removed and a tire valve (not shown) is screwed into nozzle 12. Connector 30 is then connected to the tire valve. Valve 48 is opened, and vacuum pump 46 is used to remove practically all of the air remaining in tire 10.
Connector 30 and the tire valve are removed and connector 30 is reconnected to nozzle 12. Valve 38 is opened, and an additional amount of the gaseous water is injected into tire 10 to a predetermined pressure of 3 atmospheres, for example, using pressure gauge 36. Connector 30 is removed and tire 10 is agitated, for example by spinning, for one minute or longer to dissolve any remaining gas inside tire 10 into the gaseous water.
Connector 30 is connected again to nozzle 12, and the gaseous water is injected into tire 10 to the desired standing pressure. This pressure is read with pressure gauge 36. As described above, the standing pressure is set to ensure that the dissolved gas (in this case CO2) remains in solution while tire 10 is in operation.
As described above, tire 10 is advantageously filled with gaseous water.
Apparatus 50 includes a gas solenoid valve 52, which feeds a water-soluble gas such as CO2 into a mixing block 54. The source of water-soluble gas, typically a tank, can be at a pressure in the range of 0-100 psi, for example. Mixing block 54 has a water inlet that is connected to a water line 56. Water line 56 is connected to a source of water which can be at a pressure in the range of 0-100 psi, for example. Mixing block 54 has a water outlet that is connected via a water line 58 to a pump 60. Gas solenoid valve 52 is supplied with the water-soluble gas through a gas flow regulator 63, which is optional.
Mixing block 54 can be made of plastic or stainless steel, for example. The water path through mixing block 54 contains a constricted zone 54A. A gas conduit 54B from gas solenoid valve 52 intersects constricted zone 54A. In one embodiment, the cross-sectional area of the water flow path in constricted zone 54A is 75 mm2, or 15% of the cross-sectional area of the water flow path in other parts of mixing block 54. The cross-sectional area of gas conduit 54B can be 3 mm2, for example.
As the water flows through mixing block 54, tiny bubbles of the water-soluble gas are injected into the water stream. Pump 60 can be a centrifugal pump, a piston pump, a rotary vane pump, or any other type of pump that will agitate the water sufficiently to dissolve the bubbles of water-soluble gas.
After the gaseous water leaves apparatus 50, it flows through a valve 62 and a pressure gauge 64 to a connector 66. Connector 66 can be connected to a tire valve 68.
When valve 62 is closed, pressure gauge 64 indicates the pressure in the tire. At the same time, a controller 70 detects an increase in the pressure in pump 60 and turns off the power to pump 60 and closes gas solenoid valve 52. If the operator wishes to add more gaseous water to the tire, he opens valve 62, reducing the pressure in pump 60. In response to this reduction in pressure, controller 70 turns pump 60 on and opens gas solenoid valve 52.
An alternative embodiment of an apparatus for generating gaseous water is shown in
When switch 76 is turned to the on position, magnetic contactor connects the power lines to gas solenoid valve 52, pump 60 and gaseous water solenoid valve 74. As described above, bubbles of the water-soluble gas are injected into the water in mixing block 54, and these bubbles are dissolved in the water in pump 60 to form gaseous water. When switch 76 is turned to the off position, pump 60 is turned off and solenoid valves 52 and 74 are turned off.
The apparatus shown in
Initially, connector 98 is connected to nozzle 12, and manual switch 106 is set in the “1” position. In this position controller 104 closes solenoid valve 90, opens solenoid valve 100 and turns vacuum pump 102 on, opening a pathway to draw the gas out of tire 10. Acting via controller 70, controller 104 also closes solenoid valve 52 and turns off vacuum pump 60. After the gas has been evacuated from tire 10, the operator sets manual switch 106 to the “2” position. In this position, controller 104 opens solenoid valve 90, closes solenoid valve 100, and turns vacuum pump 102 off. Controller 104 also sends a signal to controller 70. Controller 70 thereupon turns pump 60 on and opens gas solenoid valve 52, causing apparatus 50 to generate gaseous water as described above. The gaseous water can have a solubility of 1.0 volume, for example. The operator can monitor the pressure in tire 10 by observing pressure gauge 92. When the desired standing pressure in tire 10 is reached, the operator pushes the “reset (stop)” button on manual switch 106, closes connector 98 and disconnects it from nozzle 12. With manual switch 106 in the “reset (stop)” position, controller 104 closes solenoid valves 90 and 100 and turns off vacuum pump 102. Controller 104 also sends out a signal which causes controller 70 to turn off pump 60 and close solenoid valve 52.
According to another aspect of this invention, a gaseous liquid generator uses a centrifugal pump to agitate a “rough” mixture of liquid and gas (in the form of small bubbles). Known gaseous liquid generators fall into several categories. In the first category, represented by U.S. Pat. Nos. 5,842,600 and 5,510,060, a gas and a liquid are injected into a block that contains a spiral or curved passageway. The gas and liquid are blended as they pass through the passageway. In the second category, represented by U.S. Pat. Nos. 5,417,146 and 5,743,433, a liquid is forcibly sprayed into a chamber that contains an atmosphere of the gas, causing the liquid to absorb the gas and fall to the bottom of the chamber as a gaseous liquid. In the third category, represented by U.S. Pat. No. 5,443,763, a gas and a liquid are injected into a cold chamber that is filled with a slush of the gaseous liquid. A rotating blade slowly agitates the mixture, naturally blending the gas and the liquid. The amount of gas into the gaseous liquid is controlled by the period of agitation. The rotation of the blade does not build up a high pressure. In the fourth category, represented by U.S. Pat. Nos. 4,643,857, 6,736,377 and 5,275,762, a liquid is discharged through an opening into a gaseous atmosphere, creating a suction head at the opening in a direction perpendicular to the flow of liquid and causing the gas to be absorbed into the liquid (a phenomenon frequently referred to as Venturi action). The velocity of the flow and the length of the discharge from the outlet determines the size of the head and the amount of gas that is absorbed into the liquid.
In contrast a gaseous liquid generator 120 in accordance with the invention is shown in the schematic diagram of
Gas flow line 122 is connected to source of gas at constant pressure, which could be a gas tank or a gas pump operating through a pressure regulator. Connected in gas flow line 122 are a gas flow regulator 130, a back-flow valve 132, and a gas solenoid valve 134. Gas flow regulator 130 may be a needle valve.
Liquid flow line 124 is connected to a source of liquid at a constant pressure, which can be an elevated reservoir or the discharge of a liquid delivery pump. Connected in liquid flow line 124 are a liquid flow regulator 136 and a back-flow valve 138. Liquid flow regulator may be a gate valve.
The pressure of the gas in gas flow line 122 is normally set at a higher level than the pressure of the liquid in liquid flow line 124. If this is the case, no Venturi action is required in mixing block 128, and the liquid flow channel in mixing block 128 may have a uniform cross-sectional area. In other embodiments, the liquid flow channel in mixing block 128 may include a constricted “bottleneck” region where the gas flow channel intersects the liquid flow channel.
Connected in gaseous liquid line 126 are a centrifugal pump 140 and a gaseous liquid solenoid valve 142. Centrifugal pump 140 is preferably a high-pressure, closed-impeller type, and it has a housing that is made of stainless steel, plastic or some other non-corrodible material. Pumps that can be used include the LGB plastic open impeller centrifugal pump (Model CF 1493), the PEDROLLO stainless steel closed impeller centrifugal pump (Model JCRM1B), and the RESUN plastic magnet centrifugal pump (Model MD-40). Solenoid valve 142 may be omitted in some embodiments.
The gas in gas flow line 120 and the liquid in liquid flow line 124 are pre-mixed roughly in the “T” mixing block 128 such that small bubbles of the gas are entrapped in the gas/liquid mixture as it leaves mixing block 128. The impeller vanes of centrifugal pump 140 agitate this gas/liquid mixture, and the high-pressure inside centrifugal pump 140 forcibly dissolves the small gas bubbles to produce a homogeneous gaseous liquid at the outlet of centrifugal pump 140.
The mixing action inside the housing of centrifugal pump 140 agitates and thoroughly blends the rough mixture of gas and liquid that leaves mixing block 128. The rotating impellers inside centrifugal pump 140 provide a pumping action and a high pressure which produce a homogeneous blend of gas and liquid. The amount of gas in the gaseous liquid produced by centrifugal pump 140 is controlled by adjusting gas flow regulator 130 and liquid flow regulator 136. In some embodiments, liquid flow regulator 136 is maintained at a constant setting and the proportion of gas in the gaseous liquid is controlled by adjusting gas flow regulator 130.
Gas solenoid valve 134 is closed whenever the inlet or outlet to centrifugal pump 140 is turned off. This prevents the gas from flooding centrifugal pump 140, which can cause centrifugal pump 140 to surge.
Back-flow valve 132 prevents the liquid in liquid flow line 124 from flowing back into gas flow line 120 when centrifugal pump 140 is turned off. Back-flow valve 136 prevents the gaseous liquid from flowing back into liquid flow line 124.
The method and apparatus of this invention can be used to produce gaseous liquids containing more than one gas and/or more than one liquid. For example,
Flow lines 122, 124 and 146 are connected to the inlet ports of an “X” mixing block 154. The outlet port of “X” mixing block 154 is connected to centrifugal pump 140.
In the same manner described above in connection with gaseous liquid generator 120, the gas in gas flow line 120, the liquid in liquid flow line 124, and the gas or liquid in gas/liquid flow line 146 are pre-mixed roughly in the “X” mixing block 154 such that small bubbles of the gas are entrapped in the gas/liquid mixture as it leaves mixing block 154. The impeller vanes of centrifugal pump 140 agitate this gas/liquid mixture, and the high-pressure inside centrifugal pump 140 forcibly dissolves the small gas bubbles to produce a homogeneous gaseous liquid at the outlet of centrifugal pump 140.
For example, gaseous liquid generator 144 may be used to produce a carbonated beverage, where gas flow line 122 would supply carbon dioxide gas, liquid flow line 124 would supply water, and gas/liquid flow line 146 would supply a liquid syrup.
There are numerous other uses of the gaseous liquid generator of this invention. For example, a gaseous liquid generator can be used to provide aerated/ozonated water for agricultural uses such as fish and shrimp farming and in sewerage plants. Or ozone and/or carbon dioxide can be dissolved in water and used to wash or sterilize hair, feet, and other body parts.
The gas dissolved in water 164 will escape into the atmosphere, but over time the injection of gas into water 164 by pump 166 will keep the gas content of water 164 stable. The injection rate of the gas is controlled by adjusting either the pressure regulator 174 or the flow regulator 178. Pump 166 is preferably made of stainless steel or plastic or some other non-corrodible material, because carbonated/ozonated water can be somewhat corrosive.
Thus the tub 162 shown in
Moreover, the arrangements shown in
An aerator/ozonator 230, shown in
In one embodiment, the action of pump 270 produces a vacuum pressure (suction head) of 1 to 20 feet of water at air inlet nozzle 284, thus reducing the power demands on the air/ozone pump that feeds air line 282. In cases where pump 270 is placed at sufficiently shallow depth in the water such that the water pressure surrounding pump 270 is less than the suction head created by pump 270, no air/ozone pump would be required.
In aerator/ozonator 300, shown in
Aerator/ozonator 310, shown in
Although the present invention is illustrated in connection with specific embodiments for instructional purposes, the present invention is not limited thereto. Various adaptations and modifications may be made without departing from the scope of the invention. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description.