Patent ID: 6739434
Filing Date: 2004-05-25
Classification: F16C,F16D,Y10T

Abstract:
In a drum-in-hat park brake assembly for a vehicle having a first brake shoe and a second brake shoe that are respectively retained on a backing plate that is secured to said vehicle, said first brake shoe and said second brake shoe each having a first web with a first engagement end and a second engagement end, said first engagement end of each of said first and second webs being aligned with an anchor and an actuator assembly while said second engagement end of each of said first and second webs being spaced apart by an adjuster mechanism, spring means attached to said first and second webs for urging said first and second webs toward said anchor, actuator assembly and adjuster mechanism, said actuator assembly including a housing with a first end that engages said first web and a second end that engages said second web, a lever that is pivotally retained in said housing that has an actuation transmission surface on said first end that engages said second web and a second end with a first hook thereon, said actuation transmission surface transmits an actuation force from an operator into the second engagement end of said first web while said housing transmits said actuation force into the first engagement end of said second web to move first and second friction members associated with said first and second brake shoes into engagement with a drum to effect a brake application, said actuator assembly being characterized by a linkage connected a cable for communicating said actuation force to said hook, said linkage being formed from a substantially continuous wire with a first engagement section that is separated from a second engagement section by a center section, said continuous wire having first and second parallel legs that extend a first distance from a base of said first engagement section and thereafter converge toward a plane that is perpendicular to a center of said base to define a first loop that extends from said center section, said first loop being connected to said first hook on said lever, said parallel legs extending from said first loop along said plane a desired length to a first tangent point to define said a desired length for said center section, said parallel legs thereafter extending from said first tangent point along a first arcuate path for at least 135Â° to a second tangent point to define a first arcuate section, from said second tangent point a second distance to a third tangent point, from said third tangent point along a second arcuate path toward said center section for at least 135Â° to a fourth tangent point to define a second arcuate section, and from said fourth tangent point a third distance to an end to define a second hook for said second engagement section, said end of said second hook being spaced apart from said center section a distance that is less than a radius of said first arcuate section such that a resilient force is required to move the end of said second hook in said plane away from said center section, said cable being defined by a second loop that is received by said first arcuate section after expanding said end of said second hook away from said center section such that said second loop is now aligned within and retained by said first arcuate section and as a result said actuation force is substantially transmitted from said cable into said center section to move said lever in effecting said brake application.