The field of the invention is safety systems for car racing.
The high rate of speed of race cars has been a factor in making car racing a popular and growing sport in the United States and around the world. Unfortunately, the high speed also makes the sport a very dangerous one. Accidents, sometimes fatal, do occur.
Stock car racing, in particular, has become very popular in the U.S. The most well-known organization for this type of racing is the National Association of Stock Car Auto Racing (NASCAR). In NASCAR racing, sedan cars race around an oval track. Along the outer perimeter of the track is an outer wall to protect the spectators. Many accidents in NASCAR racing occur as a result of the cars drifting into or colliding with the outer walls at a high rate of speed.
In an effort to reduce this danger, NASCAR has begun utilizing the Steel and Foam Energy Reduction (SAFER) system, also referred to as “soft walls.” These soft walls are placed all around outer walls of certain NASCAR tracks. The soft walls are designed to cushion a car that hits the outer wall with the intention of reducing the likelihood of a serious accident. However, as will be more fully described below, the soft walls may have a serious and dangerous shortcoming. The soft walls may cause cars drifting into the walls to stick to the walls instead of safely sliding along the walls. As a result, the soft walls may actually increase the likelihood of a dangerous accident.
An object of this invention is to provide an alternative system to the soft wall system currently employed by NASCAR that better reduces the likelihood of race car accidents involving the outer walls. In this regard, it is a further object of this invention to provide a race car safety system in which race cars safely slide along a race track outer wall upon impact, rather than stick to the outer wall.
The present invention overcomes the shortcomings of the prior known race safety systems. Briefly stated, the invention provides a race car safety system comprising a car with at least one roller or shoe positioned on the exterior of the car so that the roller or shoe will come into contact with a racetrack outer wall if the car contacts the outer wall. In another embodiment, in addition to the roller or shoe on the race car, the racetrack outer wall will have a hard strip at the position where contact with the roller or shoe is likely to occur.
The features and advantages of the various embodiments will become apparent from the following detailed description in which:
a illustrates an exemplary path of a race car that experiences sticking to an outer wall after a collision.
b illustrates an exemplary path of a race car that experiences sliding along and off of an outer wall after a collision.
In the Figures, the same numerals are used to indicate the same or similar parts.
The rollers 30 are preferably made of a hard material. The hard material should at least be hard enough to withstand an impact of the car 100 and a race track outer wall. However, the hard material needs to still permit metal forming processes. One example of a hard material that can withstand the impact but is still formable is manganese steel.
The strip 70 is preferably made of a hard matter. Examples of hard matters that could be used include high carbon cast iron or steel. The strip 70 is preferably attached firmly to the outer wall 90, which is likely made of concrete, such that the strip 70 will not be damaged by the most violent contact by the car 200.
a and 9b illustrate how the invention makes race car driving safer.
Alternatively,
As mentioned above, the rollers 30 or shoe 40 and strip 70 should be made of hard material. In addition to reduced friction between two parts made of hard material, there also is a reduced likelihood of spalling.
A major factor in the danger of an accident in a car race is the sudden deceleration of the car 200 after a collision into the outer wall 90. The sudden deceleration of the car can seriously injure a driver even if the driver is secured by a safety belt/harness system. The race car safety system described in the invention reduces deceleration forces on NASCAR-type sedans when a contact is made between car and outer wall. This type of contact often occurs after the car 200 has just made a turn and approaches the straight section of the outer wall 90, especially on large racetracks, or “super speedways.” It is at this point that cars 200 are inadvertently contacted by following cars due to differences in speed and “line” used when coming off a long sweeping turn.
Whether the car colliding with the outer wall sticks to the outer wall, and, therefore, sudden deceleration occurs, or the car slides along the wall may depend on the angle at which the car hits the outer wall. There is a smaller “safe” angle range with soft walls (walls utilizing the SAFER system, for example) than there is with hard walls (walls utilizing the strip 70, for example). This is because softer outer walls are stickier than hard harder walls. Accordingly, hard walls provide a larger range of angles at which the car can collide with the outer wall and harmlessly slide down and off the outer wall.
In other words, hard material of the car colliding with hard substance of the strip causes reduced coefficient of friction as compared to when a car without hard material collides with a soft wall. This reduced coefficient of friction reduces the calculated width of the critical range of angle within which the car will stick instead of slide.
The following experiment explains the concept of softer walls being stickier: Place a new, unsharpened pencil, eraser down, on a formica table or shelf, with the other end leaning against a smooth vertical surface. If there is no dust to prevent contact, the eraser sticks to the table surface. The angle the pencil makes with the wall can be almost 45 degrees before the pencil slides down. If you tap on the top of the pencil with the handle of a butter knife, the eraser just sticks tighter to the table.
Now put a piece of waxed paper under the eraser end. Obviously, the pencil starts sliding down at a much higher angle. Tapping with the knife on the top end causes the bottom to slip more easily.
This illustrates there is a critical range of angle where the corner of the car tries to stick to the outer wall rather than sliding off. Put another way, there is a critical range of angle within which the resolution of the reactive force of the wall against the car will show a high ratio of perpendicular to parallel force, causing sticking. Also, observation of the film or tape record of various NASCAR crashes shows that the car does not acquire much spin momentum during contact with the wall (only 0.08 seconds in the one case). Therefore, the resolution of the forces can be done without consideration of the spin.
In most cases, when cars collide with outer walls, the cars do not hit a wall straight on. Cars usually negotiate most of the turn, and run into the wall at a low angle, while heading for the straight portion of the track. This was the case in the well-known fatal accident involving Dale Earnhardt.
The invention accomplishes two conditions in complete opposition to the theory of the soft walls. First, the energy absorbing property of the soft wall is switched to the vehicle, whereas the wall is hardened. Second, the soft walls have exhibited a stickiness even worse than the concrete wall. The friction between the two hard metals will be one eighth of this amount, or less.
This application claims the benefit of U.S. Provisional Application No. 60/507,866 filed on Oct. 1, 2003, which is incorporated by reference as if fully set forth.
Number | Date | Country | |
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60507866 | Oct 2003 | US |