Innovations in vehicle tire technology, including monitoring and maintenance, help to increase auto and truck fuel economy. A recent New York Times article, "More Traction for Fuel-Efficient Tires" discussed some of the approaches being taken to improving traction while at the same time reducing the rolling-resistance of tires, which in turn leads to greater fuel economy. RubberWorld reports that the global demand for tires is expected to reach 3.3 billion units in 2015. The potential fuel cost associated with the rolling resistance, and improper inflation, of that many new tires (not to mention the existing ones that won’t be replaced that year) is huge. We offer a brief survey of tire technology that can help mitigate increased fuel costs.
They're not just rubber
Tire technologists have worked to modify the formulation of the rubber and other compounds used in vehicle tires since pneumatic rubber tires were invented in the 1800s. Silica (the major component of quartz sand) added to tire rubber serves as a reinforcing agent and helps to reduce the rolling resistance of tires. A recent invention related to tire rubber composition including silica is US 8,336,591, "Pneumatic tire with rubber component containing carboxymethylcellulose [CMC]," issued on Christmas Day 2012 to Klaus Unseld (Luxembourg) and co-inventors and assigned to The Goodyear Tire & Rubber Company (NASDAQ: GT) (Akron, OH). Unseld et al. not only use silica in their formulation, but also incorporate carboxymethylcellulose:
The present invention is directed to a pneumatic tire comprising at least one component, the at least one component comprising a rubber composition, the rubber composition comprising: at least one diene based elastomer; and a reinforcing amount of at least two fillers comprising carboxymethylcellulose (CMC) and at least one of silica and carbon black.
They point out that "the use of renewable materials as reinforcement in rubber compounds in place of carbon black and silica is desirable from an environmental standpoint." You've encountered CMC in your daily activities. It is used:
- As a thickener and emulsion stabilizer in various products including ice cream
- In personal lubricants, toothpaste, laxatives, diet pills, water-based paints, detergents, textile sizing, and various paper products
- In laundry detergents
- As a lubricant in nonvolatile eye drops (artificial tears)
- In pharmaceuticals as a thickening agent
- In the oil-drilling industry as an ingredient of drilling mud, where it acts as a viscosity modifier and water retention agent
- In ice packs to form a low freezing point mixture providing more cooling capacity than ice
- To aid in tartrate or cold stability in wine, which can reduce electricity consumption for chilling wine in warm climates.
Just when you wondered how much more expensive and complicated cars can get, and how little of a modern automobile you, the owner/operator, can service yourself, come complex new millennium tire inventions.
Robert Angelo Fiore (East Longmeadow, MA) patented and retained the rights to US 7,066,226, "Fuel efficient vehicle tire having a variable footprint and low rolling resistance", issued in June 2006. Fiore invented a system of active tire tread, connected to a computer-based tire control system, in which
the ground-contact surface area is variable as a portion of the tread part can be retracted and/or extended using pneumatic, mechanical or hydraulic force to withdraw from, or come into contact with the road surface before, during or after operation permitting more efficient operation wherein the material used within the tread part that retains contact with the road may generally have a smaller internal friction loss than the material used in conventional tires and the rolling resistance is thereby reduced when the retractable portion of the tread is selectively withdrawn from contact with the road surface furthermore achieving a smaller ground-contact patch footprint.
After reading that you'll be glad to know that the tire also reduces interior and exterior noise and provides a "reduced tendency to exhibit hydroplaning action." No more stops at the gas station air pump.
According to the US Department of Energy, "You can improve your gas mileage by up to 3.3 percent by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.3 percent for every 1 psi drop in pressure of all four tires." Automated tire inflation systems are one approach to maintaining proper tire pressure. The most-cited US patent (based on the title) in this technology is US 4,431,043, cited 41 times by more recent patents. "Automatic tire inflation system" was invented by Fred Goodell (Grosse Ile, MI) and Michael Ellison (Canton, MI), granted on Valentine's Day 1984, and assigned to AM General Corporation (Detroit, MI). The company has "a legacy dating back to America's first 4-wheel drive utility vehicle - the Willys Jeep of World War II – AM General is best known today for its global leadership in the design, production and support of the High Mobility Multi-Purpose Wheeled Vehicle (HMMWV or Humvee) … ." The invention provides
is also provided. The focus of the invention is toward military vehicles, but the technology can also be found in commercial applications.
[a]n automatic tire inflation/deflation system for a vehicle … . Air passageways for the pressurize air are provided internally through the wheel assemblies without cutting into load bearing members. A rotating seal is provided by way of a pair of sealing rings located inboard of the hub bearings to protect the seals from adverse environmental conditions. A kit for retrofitting vehicles to include an automatic tire inflation/deflation system
This is not the earliest patent for this technology, however. Arthur W. Stonestreet (Pasadena, CA) received US 1,338,337, "Automatic pneumatic, pneumatic-tire-inflating mechanism," in April 1920. He stated that “[t]his invention relates to the automatic inflation of pneumatic tires and the object of my invention is to provide means for automatically the tire while in motion.""
And what about tire pressure monitoring? A recent patent, US 8,326,480, "Method and device for monitoring the state of tires,” was granted in December 2012 to Andreas Kobe (Bensheim, Germany) and co-inventors and assigned to Continental Teves AG & Co. oHG (Germany). It provides for measuring variables such as wheel speed, wheel rolling circumference and determining tire pressure from calculations based on these factors. We should note that this patent has been classified by USPTO as a software patent. Good? Bad? Shouldn’t have been granted? Perhaps the inventors’ statement of purpose, expressed in the Field of Invention section, sheds some light for those that desire software patents to be eliminated:
… systems which contribute to active or passive protection of the vehicle occupants are being increasingly used. Systems for monitoring the tire pressure protect the vehicle occupants against injury which would otherwise be caused, for example, by an abnormal tire pressure. An abnormal tire pressure can, for example, increase the wear of the tire and the consumption of fuel, or a tire defect (’flat tire) may occur.
But again, as with automated tire inflation systems, it’s been done before. In January 1920, Louis Anderfuhren (Baltimore, MD) probably celebrated his receipt of US 1,327,416, “Pneumatic-tire alarm.” He wrote:
This invention relates to devices applicable to pneumatic tires used on motor vehicles, and operating to give warning when the tire becomes deflated to such an extent that it is liable to be damaged if the driver continues to run the car.
Basically, the invention was for a bell and clapper mounted on the car wheel in such a way that when the tire begins to deflate, the clapper is actuated via a spring and rings the bell. This would have worked to gain the driver’s attention in an age without in-car radios, sound systems, multi-megawatt woofers, iPods, cell phones, and in-car entertainment systems.
Per the USDOE, tire pressure affects gas mileage. Akihiro Taguchi (Obu, Japan) provides a "Device for displaying fuel efficiency degradation amount based on tire air pressure", issued in March 2009 and assigned to DENSO Corporation (T: 6902) (Kariya, Japan). US 7,501,940 is a succinct invention with only two claims, describing
A fuel efficiency degradation amount displaying device detects a tire air pressure and calculates an amount of degradation of fuel efficiency of the vehicle compared to fuel efficiency in a case that the tire air pressure is appropriate. Then the fuel efficiency degradation amount displaying device indicates not only a warning of the decrease of the tire air pressure but also the amount of the fuel efficiency degradation. Therefore the driver can recognize the amount of the degradation clearly and intuitively. As a result, it is possible to prevent drivability of the vehicle from getting worse, because the driver can adjust, knowing a relation between the tire air pressure and the fuel efficiency, the tire air pressure to the appropriate tire air pressure.
Taguchi was beaten to the punch by Vernen E. Rouch and Willim J. Abbott (Fulton, IN) in their December 1927 patent, US 1,652,733, “Electrical tire-pressure indicator.” From their patent:
The present invention relates to an air pressure indicating device to be employed in connection with pneumatic tires of motor vehicles for signaling to the operator when the air pressure within a tire has reached a dangerously low degree.
Another object of the invention is to provide a device which will be purely automatic in its operations and one which is electrically controlled. Did you think that electrical, automated tire pressure indicators were a relatively recent innovation?
Your tire pressure dictates your route
We"ve looked at tire compound formulations, active tires, automated tire pressure, and tire indicators. Want to get the best fuel economy for the route you would have taken on a road trip had gas prices been lower and you had more disposable income after paying for groceries, medical visits and insurance, utilities, and increased taxes? Peter G. Hartman (Bloomfield, MI) provides help for that in US 8,374,781, “Method for vehicle route planning,” issued in February 2013 and assigned to Chrysler Group, LLC (Auburn Hills, MI). The invention gives:
A method of planning a vehicle route includes estimating fuel requirements of identified alternative routes or route segments using navigation, vehicle, and powertrain information. The method also includes displaying for a vehicle operator a list of alternate routes that features either absolute or relative values representative of such estimated fuel requirements. The method further includes adapting values used to estimate fuel requirements based upon current powertrain operating parameters, and alerting the vehicle operator when actual vehicle fuel economy along a selected route varies significantly from the estimated fuel requirement.
Tire rolling resistance is one of the factors that is included in the calculations. Further, the inventor considers this to be a clean tech invention:
...a vehicle’s electronic navigation system utilizes navigation information and vehicle and/or powertrain information to identify one or more routes that a vehicle operator may take to arrive at a desired destination which achieves increased vehicle fuel economy, i.e., that will use less fuel, or that results in reduced vehicle emissions, e.g., reduced CO2 emissions.
Hartman and Chrysler did not take advantage of accelerated examination under the USPTO's Green Tech Pilot Program, which probably would have reduced the pendency of this invention, and thus time-to-market for this Chrysler product. Oh yes, this one is a clean tech software patent too.
Everything old is new again.
Inventors continue to innovate to address actual and perceived societal needs. Many of the clean tech inventions we now see are incremental changes to old technology, taking advantage of new materials, processes, and supporting technologies. This is not bad, in fact, it is completely consistent with the history of invention. There are few truly disruptive, transformative, ex nihilo inventions; most are incremental, moving forward in fits-and-starts, and build on past innovations. There is a higher degree of convergence – different technological systems that evolve toward performing similar tasks – like the iPad is a portable computer is a camera is a digital recorder is an ebook reader is a portable movie theater is a portable music library and stereo is a portable photo album. Like that.