Sliding exhaust brake system

A sliding exhaust brake system comprising:

• a housing having an exhaust passage extending therethrough and a valve working space communicating with the exhaust passage;
• a main valve mounted in the valve working space for reciprocating movement into and out of the exhaust passage, the main valve comprising a generally flat bottom wall for selectively blocking the exhaust passage, an exhaust pressure adjusting hole extending through the bottom wall;
• a cylinder and piston assembly mounted in proximity to the valve working space of the housing, said assembly comprising a piston rod having an end reciprocally movable in the valve working space selectively toward and away from the exhaust passage;
• a block mounted to the piston rod in spaced relationship to the end thereof, said block being disposed to engage the main valve in response to movement of the end of the piston rod away from the exhaust passage;
• a support frame of substantially C-shaped cross section, said support frame comprising a base and a pair of arms connected to and extending from the base, said base being mounted to said piston rod intermediate the end thereof and the block;
• and
• a liner comprising a generally flat portion slidably movable along the flat bottom wall of the main valve for selectively opening and closing the exhaust pressure adjusting hole extending through the bottom wall, said liner comprising a pair of opposed longitudinal ends angularly aligned to the flat portion thereof and extending away from the bottom wall of the main valve member, said ends of said liner being loosely engaged intermediate the base and the arms of the support frame, said liner further comprising at least one tongue disposed intermediate the support frame and the bottom wall of the main valve for preventing contact between the support frame and the bottom wall of the main valve, wherein movement of the end of the piston rod away from the exhaust passage moves the liner away from the exhaust pressure adjusting hole and subsequently urges the block against the main valve for urging the main valve out of the exhaust passage, and wherein movement of the end of the piston rod toward the exhaust passage urges the liner over the exhaust pressure adjusting hole and urges the main valve into the exhaust passage.