BRAKE ACTUATING PRESSURE PROPORTIONING SYSTEM AND PROPORTIONER MODIFYING ARM THEREFOR

摘要

BRAKE ACTUATING PRESSURE PROPORTIONING SYSTEM AND PROPORTIONER MODIFYING ARM THEREFOR A brake pressure proportioner is mounted on a sprung portion of a vehicle and is attached to an unsprung portion by means of a modifying arm. The arm has ends pivoting on the unsprung portion and on a proportioner control arm so that the arm maintains a constant length during relative movements of the vehicle sprung and unsprung portions, modifying the action of the brake proportioner in accordance with such movements. The movements are proportional to vehicle load. The arm provides for compression or extension without affecting the proportioner when unsprung movements between grows vehicle curb weight (no load) and gross vehicle full weight (full load) positions are exceeded in either direction. The movement of the unsprung portion of the vehicle below the position for curb weight is known as rebound and above the curb weight position is known as jounce. The excess jounce travel beyond the gross vehicle full weight causes the arm to compress without further modifying the proportioner. The rebound travel of the vehicle unsprung portion permits the arm to extend without affecting the proportioner and also keeps the arm located in its proper relation with the vehicle sprung and unsprung portions. A modification uses a spring as the modifying arm. The proportioner is arranged so that the spring will extend upon jounce, will maintain its effective length when unsprung movements occur between the gross vehicle curb weight and the gross vehicle full weight positions, and will decrease its effective length when the unsprung movement exceeds the gross vehicle full weight position in the rebound direction.