Air Compressor and Reservoir For Topping Off Low Pressure Tires

Abstract

A small volume capacity pump is used to pressurize a small air tank, and the tank is used to top off pressure in an automobile tire or other receptacle. The tank preferably has a reservoir measuring 200-300 cc, and is pressurized to at least 500 psi. The pump preferably has a low volume capacity of 200-300 cc/min, thus requiring at least 15-45 minutes to refill the reservoir to its full operating pressure when empty. A pump can be operated by a DC or AC motor, which can be housed along with, or separately, from the pump. Especially preferred embodiments also include an automatic pressure regulator that can be set to deliver a desired pressure to a receiving device, and a trigger that controls release of air from the tank to the regulator.

Description

[0001]This application claims priority to U.S. provisional application No. 60 / 947,579, filed Jul. 2, 2007, which is incorporated herein by reference herein in its entirety.FIELD OF THE INVENTION[0002]The field of the invention is tire pumps (152 / 417).BACKGROUND[0003]It is well known that automobile tires, sports balls, pool floats and other pressurized devices tend to leak over time, and require additional air from time to time to maintain a proper air pressure. The problem is especially significant for automobile tires, where (a) tires tend to lose about one pound per square inch (psi) per month, and (b) even moderately low tire pressures (3-4 psi below target) result in noticeably lower gas mileage and tire life.[0004]The usual method of maintaining automobile tire pressure is to use compressed air sources at a gas or service stations. Unfortunately, such sources are often either impractical or completely unavailable. Gas stations typically have only a single air hose for customer...

AI Technical Summary

Benefits of technology

[0015]The pump can connect to the electrical system of the vehicle in any suitable manner, but most preferably using a cigarette lighter plug or other de connection. The power cord can be hard-wired to the air tank housing, or more preferably has an electrical connector on the opposite end from the cigarette lighter plug, so that the housing can be removed from the vehicle and used to top off the tires, all while the electrical system of the vehicle is disconnected from the pump. To that end the power cord can be relatively short, perhaps only a foot or two in length. Longer power cords are contemplated, including those longer than 30 inches, but such lengths are thought to be unnecessary since the power cord need not extend from the cigarette lighter all the way out to the tires.

[0016]In still other contemplated embodiments, the housing that includes the pump can be separated from the housing that includes the air tank, and coupled via high-pressure air hose connection.

[0017]Because the air tank is relatively small, it is possible that considerable air pressure can be lost while trying to seat the pressure hose from the tank onto the pressure stem of the tire. One contemplated way of addressing that problem is to pressurize the hose only while a button or other trigger mechanism is being operated. Another contemplated way of addressing the problem of limited air supply is by providing a pressure regulator that delivers a pre-set pressure to the tire. Thus, for example, a user might set the unit at 35 pounds, connect the hose to the tire stem, and then actuate the trigger. Doing so will deliver sufficient air to the tire to provide an equalized pressure of 35 pounds± some tolerance.

[0018]Tanks are preferably small enough to fit in a standard automobile glove compartment, Typical contemplated tank sizes are 200-500 cc (cm3), but could go up to a liter or more, depending on the shape. Suitable tanks should have sufficient capacity to top off one or more tires that are several pounds below a target pressure. For relatively small tanks this means that the tanks must be pressurized 500-1200 psi, or even higher pressures, and must have sufficient wall strength to withstand such pressures. For such high pressures, and especially since the tank might well be stored in the glove compartment of a hot car, it is also considered advantageous to include a pressure relief valve.

[0019]The hose that delivers pressurized air from the tank to the tire need not be very long, and indeed hoses longer than about 10 inches can be problematic in that the extra hose is takes up valuable space in storage. Preferred hoses (air conduits) have lengths of no more than 12 inches.

[0020]Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawings in which like numerals represent like components.

Problems solved by technology

It is well known that automobile tires, sports balls, pool floats and other pressurized devices tend to leak over time, and require additional air from time to time to maintain a proper air pressure.

The problem is especially significant for automobile tires, where (a) tires tend to lose about one pound per square inch (psi) per month, and (b) even moderately low tire pressures (3-4 psi below target) result in noticeably lower gas mileage and tire life.

Unfortunately, such sources are often either impractical or completely unavailable.

Gas stations typically have only a single air hose for customer usage, and one or more other customers may well have to wait in line for an uncomfortable period of time to use the air hose.

Another problem is that tire pressure should be checked when the tires are cold, or at least substantially cold.

Other known options are too inconvenient for many car owners.

But the 32-34 psi pressures that are standard for automobile tires typically require a foot operated pump, which is too awkward or otherwise inconvenient for many users.

They are far too expensive and too bulky for many automobile owners, and are certainly too bulky to be carried about in an automobile by a typical user.

But such canisters often contain a sealing compound, which one would not want to use when merely topping off pressure in a tire.

Pressurized canisters without sealing compound are also known, but they are impractical.

PowerTank™ and other liquid CO2 canisters are convenient, and useful for emergency use, but are quite expensive in the long run if used to top off tire pressure because they are not refillable by a typical user.

But they have a relatively large size because the maximum pressure afforded by gas stations and home compressors is only about 90 psi.

But even those devices are too bulky because they are intended for use in refilling a flat tire.

In addition, such devices are inconvenient to use and store because they need to have long power cords or air tubes (5 meters or more) to reach each of the tires of a typical automobile.

Thus, in reviewing the prior art it is apparent that no one has yet solved the problem of producing a convenient device for topping off automobile tire pressure.

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