Suspension systems function to isolate occupants of a moving vehicle from the discomfort of rough or uneven terrain. Suspension systems also provide a vehicle with resistance to lateral roll of the vehicle's body during turns. As is well-known in the art, the steering mechanism for the front wheels of automobiles is typically provided with suspension ball joints between suspension arms and a steering knuckle. Various types of suspension ball joint mechanisms, such as wishbone type, MacPherson type, as well as other types, have been developed, improved and adapted for use with vehicles. The ball joints typically include flexible dust covers to resist the ingress of contaminants such as dust, dirt and debris from entering the joints. Such contaminants, if allowed to enter a ball joint, tend to act as abrasives, reducing the service life of the ball joint.
A shortcoming of current vehicle suspension designs is that they permit road-borne materials such as snow, ice and debris to accumulate proximate the dust covers. The flexible dust covers are subject to deformation due to pressure exerted by the accumulated materials, forcing the dust covers to come into contact with other nearby suspension components. Normal movement of the suspension during operation of the vehicle can subsequently cause the dust cover to be pinched by nearby suspension components, causing the dust cover to be pierced, torn or similarly damaged. This in turn allows migration of lubricants contained by the dust cover in the ball joint.
Others have attempted to provide protection for suspension ball joints. For example, U.S. Pat. No. 6,095,712 to Ridley et al., discloses a metal protective spring clip for a vehicle steering linkage joint. The protective clip includes a heat shield to protect a rubber gaiter from heat generated by a nearby disc brake assembly. However, the heat shield does not substantially surround the ball joint, the shield being intended to protect only the areas of the ball joint proximate the disc brake assembly. Consequently, the protective clip is not effective to protect the ball joint from damage by road-borne material, such as ice, snow and debris.
U.S. Pat. No. 5,100,254, issued to Wasada, discloses a shield for a ball joint. The shield is intended to protect the ball joint from flying stones and includes a body having a cup shape formed by a curved flange portion. The body is elastic to resist deformation from flying stones. However, the elastic nature of the body renders it ineffective for breaking up rigid accumulated materials such as ice or forcing the materials away from the ball joint.
A further disadvantage of current ball joint shields is that they are made as separate components and thus must be fabricated and assembled to the ball joint in some manner. This requires time and labor, adding to the cost of the vehicle. There is a need for an economical and durable way to resist the build-up of snow and ice materials proximate the dust cover of a front suspension ball joint, and to break up and disperse accumulated material.