GB827067A - Improvements in or relating to exhaust braking apparatus for motor vehicles - Google Patents

Abstract

827,067. Regulating; reservoirs. CLAYTON DEWANDRE CO. Ltd. June 1, 1956 [March 28, 1955], No. 9037/55. Classes 7(2) and 7(6) [Also in Groups XXXI and XXXIV] In a motor vehicle engine exhaust braking apparatus a closure member 2 for the engine exhaust duct 4 is actuable by a fluid pressure motor 5 operatively connected to a storage reservoir 13 charged with exhaust gas pressure as a result of the operation of the apparatus. As further shown upstream of the member 2 is provided a branch 15 connected by a pipe 14 and a non-return valve 17 to the reservoir 13, whereby exhaust gases compressed by actuation of the brake can be stored. The reservoir 13 has a connection 18 for external charging and has a pipe 22 connected by a valve 23 to another reservoir 21, the valve 23 closing the connection between the reservoirs 13, 21 when the pressure in the reservoir 13 is below that needed to operate the valve 2. The valve 2 is operated by the pressure in the reservoir 13 through a pipe 19, a valve 20 operated through a solenoid 24 and the motor 5 having its piston 6 connected by a link 7 to the member 2, the member 2 being urged into its open position by a spring 8 acting on the piston 6. The reservoir 21 has a pipe 21a leading to other fluid-pressure operated equipment (not shown) and a pipe 9a leading to a fluid pressure servomotor 9 for controlling the vehicle wheel brakes and controlled by a pedal 10 through a link 11. Mounted on the pedal 10 is a micro-switch 26 for controlling the solenoid 24 from the vehicle battery 25. A fluid pressure motor 29 under the control of the valve 20 cuts off the fuel supply when the valve 2 is closed. In order to prevent the engine stalling if the valve 2 remains closed with the engine idling, a relay 30 interposed between the microswitch 26 and the solenoid 24 is energized by the vehicle dynamo 32 through the cut out 33 normally provided between the dynamo 32 and battery 25, so that the cut out 33 opens when the engine is idling to prevent operation of the solenoid 24 by the micro switch 26. In another embodiment, Fig. 2 (not shown), the valve 20 is operated mechanically by the brake pedal 10 through a spring connection enabling the exhaust brake to be operated simultaneously with or prior to the wheel brakes. The embodiment also provides for the electric actuation of the exhaust brake valve should the pressure in the exhaust reservoir be insufficient, the electric actuation being under the control of a switch on the brake pedal. In this embodiment the two reservoirs are replaced by a single one. In another embodiment, Fig. 3 (not shown), the electric actuation by the exhaust brake valve is automatic on the reservoir pressure falling below a predetermined value, but a switch on the accelerator pedal prevents such actuation when the vehicle is being accelerated. Furthermore, the reservoir pressure falling below the predetermined value actuates a visual warning device. In a further embodiment, Fig. 4 (not shown), the exhaust brake valve is opened by pressure in the reservoir and closed by spring pressure, and the valve 20 is controlled by a hand lever. In a still further embodiment, Fig. 5 (not shown), the exhaust brake valve is actuated as in the previous embodiment (Fig. 4) and provision is made for opening the exhaust brake valve when there is insufficient pressure in the reservoir and the vehicle is stationary with the engine stopped. Specifications 732,829 and 744,513 are referred to.