Patent Application
20070089951
1. Field of the Invention
This invention relates to protective device for air springs, in particular a non-contact protective sleeve that envelopes air springs and is easy to install on motor vehicles.
2. Description of the Related Art
Air springs are designed to provide the occupant of an automobile, truck, or other type of vehicle with a smoother ride. These springs are well known in the arts and act to reduce sharp forces caused by bumps or holes in the road. Air springs are also known in the trade as air bellows.
The OMA 95 FA Ride Rite™ Helper Springs marketed by the Firestone Corporation is a typical example of an air spring. An air spring typically consists of two sealed rubber disk like bladders. There is a valve at one end of the spring for air to be injected or removed from the bladders. The compressed air in these bladders provide the desired ‘cushion’ for the occupants in the vehicle.
The installation instructions provided with the Firestone Helper Springs are illustrative of how the springs are installed into the vehicle. An unpressurized spring is installed and then inflated under a vehicle load to an air pressure that is specified in the instructions. During movement of the vehicle, air delivery systems can also be installed on the vehicles to inflate or deflate the bladders for the purpose of changing the suspension characteristics of the air spring.
U.S. Pat. No. 5,265,907 to Tostado is illustrative of how an air spring is mounted to the frame of the automobile.
A sudden loss of pressure of an installed air spring will cause the vehicle to tilt to one side. While the vehicle is stationary this would have little effect, but, if this happens while the vehicle is moving, instability can result, leading to loss of control of the automobile.
Air springs are typically made from a flexible, rubber-like material. The material on the air springs is subject to puncture from sharp objects, such as flying pieces of metal. These pieces of metal are commonly found on the highway and are easily ‘kicked up’ by other automobiles. Therefore the rubber on the air spring may possibly be punctured while the vehicle is in motion, potentially leading to loss of stability in the moving vehicle.
Traditional gas shock pistons are well known in the arts. These pistons have metal casings and have different suspension characteristics than air springs.
U.S. Pat. No. 5,669,597 to Rittstieg, et al. depicts a self-pumping air suspension spring. This air suspension spring has an upper component section that is made of metal. One of the disadvantages of this device is that the integrated expansion bellows is not designed to protect the ring of flexible material directly below the metal shaft.
U.S. Pat. No. 5,480,129 to Gilsdorf, et al. describes an air spring with an integrated expansion bellows assembly. The expansion bellows is connected to the metal sleeve via a compression connection. The disadvantage of this design is that the expansion bellows makes contact with the sleeve and is not protected.
U.S. Pat. No. 4,722,516 to Gregg describes an air spring with a flexible membrane and a metal shroud that is comes into the contact with the flexible membrane. This disadvantage of this design is that the flexible membrane is an integrated assembly with the metal shroud and is in contact with the metal.
None of the aforementioned patents teach the use of protective sleeve for an air spring that does not come into contact with the expansion bellow and can be installed independently of the air spring.
It is an object of this invention to provide a protective shield for an air spring that is easy to install and durable.
It is another object of this invention to provide a protective shield for an air spring that is designed to minimize wind resistance while the vehicle is in motion.
It is another object of this invention to provide an easy way to install the protective sleeve on vehicles that do not have air springs and those that already have air springs installed.
It is another object of this invention to provide a protective shield for air springs that is designed to have minimal weight by using either lightweight materials or using existing materials with small holes.
It is another object of this invention to provide a protective shield for air springs to prevent the flexible material on the air bellows or air spring from accelerated degradation due to sun exposure.
It is another object of this invention to provide a protective shield that is attractive and supports ornamental designs on the surface of the protective shield.
The present invention discloses a protective sleeve for vehicular air springs. An air spring consists of an exposed flexible bladder mounted between the axle and the frame of the vehicle. The exposed bladder is subject to penetration by flying debris leading to pressure loss. The sudden loss of pressure may cause vehicular instability.
The protective sleeve is easy to install allowing vehicles with existing air springs to take advantage of the features of the protective device.
While describing the invention and its embodiments various terms will be used for the sake of clarity. These terms are intended to not only include the recited embodiments, but also all equivalents that perform substantially the same function, in substantially the same manner to achieve the same result.
With the protective sleeve installed over the air spring is protected against various road hazards and insults, while still allowing for the normal expansion and contraction of the air bladder. These insults can consist of flying metal, wood chips, gravel, and other debris that is present on the roadway. These insults can already be in motion having been ‘kicked up’ by the preceding vehicle.
Another feature of the protective sleeve is the ability to shield the flexible material of the bladder from exposure to the sun. Exposure of these parts to the sun causes accelerated degradation of the materials and hastens the eventual replacement.
The protective sleeve also provides protection to a person or the undercarriage of the vehicle if the air bladder should burst upon inflation or operation.
The protective sleeve can be made from any number of materials, including, but not limited to metal, plastic or composite materials. The materials should be strong enough to withstand an impact from flying debris, durable enough to withstand exposure to the elements for extended periods of time.
The protective sleeve is not required to be cylindrical. Other shapes, including box, hexagonal, elliptical, and other novel shapes may be employed. The design of the protective sleeve may be modified to reduce wind drag around the air bellow or air spring, thereby increasing vehicle efficiency.
The configuration of the protective sleeve does not have to be contiguous. It may be bifurcated in a hinged designed to aid in attachment to the air bellow or air spring. The design improves installation because an existing air spring does not have to removed to install the protective shield.
Likewise it is not necessary to have an upper protective sleeve and a lower protective sleeve. A configuration may include a single protective sleeve, either upper or lower, that extends beyond the midpoint of the air spring. In this configuration the protective sleeve assembly consists of a lesser number of parts.
Also, the protective sleeve may be made from materials that are not entirely solid, for example, a screen material with a density to prevent most particles from penetrating the sleeve.
Alternate methods of attaching the protective sleeve exist. For example, the sleeve may be clipped to the inner section of the air spring where the two bladders meet. Alternatively, the protective sleeve may be attached to other parts of the frame and axle not including the air spring mounting holes. This will aid in assembly since the air spring does not have to be removed before installation.
Because the protective sleeve may be visible from outside the vehicle, it is desirable to provide ornamentation to the exterior of the protective sleeve. This ornamentation can consist of any number of insignia's, logo's or designs. Alternatively, the ornamentation can consist of spinning designs similar to those found in automobile rims.
Although the protective sleeve has been described in conjunction with an air spring, it is understood that it may be used to protect other types of spring assembly structures.
It should be understood that various modifications within the scope of this invention can be made by one of ordinary skill in the art without departing form the spirit thereof. I therefore wish my invention to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of this specification if need be.
