Patent ID: 6994191
Filing Date: 2006-02-07
Classification: B60T

Abstract:
1. A parking brake system for a vehicle comprising: an air chamber for actuating a vehicle brake assembly; a pneumatic parking demand mechanism selectively actuated to mechanically apply a parking brake force to the vehicle brake assembly; an air connection line fluidly connecting said air chamber to a parking air reservoir; a valve assembly cooperating with said air connection line to selectively supply air to said air chamber from said parking air reservoir to apply the vehicle brake assembly in response to movement of said pneumatic parking demand mechanism; and an air cylinder having a locking component that locks the vehicle brake assembly in an applied condition wherein said locking component is pneumatically controlled in response to movement of said pneumatic parking demand mechanism and wherein said locking component has a primary locking mechanism and a secondary locking mechanism that cooperate to lock and hold the vehicle brake assembly in response to a parking demand.