Manually operated park brake control assemblies are typically positioned in the passenger compartment of a vehicle adjacent the operator and present a hand or foot operated lever to be manually operated by the vehicle operator for applying, or setting, the park brake. Generally, the hand or foot operated lever is supported on a pivot and integrally attached to a ratchet mechanism for maintaining the control assembly in an actuated condition in order to hold the park brake in the brake applied condition. The park brake is released by triggering some form of independent release mechanism.
Such prior art park brake control assemblies have two significant disadvantages. First, the entire mechanism must be located inside the passenger compartment. The physical size of the control assembly inside the passenger compartment prevents optimal use of the space in which it is located. As vehicle designs seek to conserve and better utilize all available space in the passenger compartment, such large and bulky park brake control assemblies become a greater design burden. Therefore, the first deficiency in the prior art park brake control assemblies relates to their inherently large size coupled with the unavoidable requirement that they be positioned inside the passenger compartment.
Second, flexible motion transmitting core elements, or cables, are typically used to interconnect the park brake control assembly and the park brakes at the rear wheels of the vehicle. As one park brake is located at each of the two rear wheels of most vehicles, two such cables must extend the majority of the distance between the control assembly and the park brakes. These cables must be of relatively high tensile strength because tensile forces in excess of 90 pounds can be generated between the control assembly and park brake during actuation, and maintained therebetween for very long periods of time. It will be appreciated that such high tensile strength cables are costly, heavy, and in addition are difficult to install and service due to their stiffness.
The U.S. Pat. No. 4,795,002 to Burgei et al, issued Jan. 3, 1983, discloses an electronic park brake control assembly located adjacent the brakes and having a remote actuator located inside the passenger compartment. Such fully electronic systems have not gained wide acceptance due to unreliability and difficulty in diagnosing the cause of system failures. Purely mechanical control assemblies are preferred in most situations yet cannot be divorced of their above-described disadvantages.
USPTO Backgrounds
USPTO Backgrounds