a. Screed Tow Point

TM 5-3895-373-34 a. Screed Tow Point: The main screed assembly is attached to the tractor on each side of the paving machine. These points of attachment are known as the screed tow points. The attachment is made by a metal flange plate to flange plate connection between the screed arm and screed tow arm. b. Screed Control Panels: The screed control panels are located on both the left and right sides of the screed. Each control panel protective cover can be removed to gain access for repairs. The wire connections inside the control box are composed of pin connectors and hard soldered joints. Both screed control boxes have identical control switch functions and indicators, with the exception that the left control box is also configured with a fuel pump switch and indicator. The dual screed control box configurations allow for the positioning of two screed operators, or allows a single screed operator convenient access to controls for safe machine operation. The screed control boxes contain the following switches: (1) Extension Screed Control (2) Extension Screed Blower (3) Extension Screed Burner Control (4) Tow Point Movement (5) Auger/Conveyor Reverse Control (6) Feeder Control (7) Flow Gate (8) Emergency Stop (9) Fuel Pump (left control panel only) (10) Main Screed Blower (11) Main Screed Burner Control (12) Panel Light c. Extension Screeds: The extension screeds are hydraulically operated with two extension screed height adjustments mounted on each extension screed to control the desired slope. The height adjustments can be raised or lowered independently of each other by removing a quick release pin from the adjusting wheel shaft. Quick release pins are not removed from the adjusting wheel shaft if the same adjustments are required. d. Thickness Control: Paving mat thickness is changed by altering the setting of the thickness control, which changes the angle of the screed in relation to the surface being paved. This is referred to as angle of attack. The thickness control is operated by a manual hand crank mounted in a mounting bracket supported by two roller bearings. The hand crank shaft is attached to a universal joint which is connected to a threaded rod and link bolted to the screed arm. e. Screed Vibrators: The screed vibrators are hydraulically driven and operated by toggle switches on the operator control panel. The main screed is configured with two vibrators connected with two universal joints on rotating shafts. Each extension screed is configured with one vibrator each. f. Screed Burners/Blowers: The screed is equipped with four independently controlled burners and blowers to increase the temperature of a cold bottom screed plate to approximately 300°F (150°C). The burners are diesel fuel atomizing, configured with a burner chamber and an internal fuel nozzle. Each burner chamber has a glow plug used for the fuel ignition. Each burner is also equipped with an exhaust heat distribution duct to deflect the hot air evenly across the screed plates. Each fuel burner has a blower assembly driven by a 12 volt DC motor mounted on support brackets. The fuel burner is attached to the blower with a steel flexible pipe connected at the blower exhaust and the burner chamber inlet. 1-22