GB660622A - Road-paving machine - Google Patents

Abstract

660,622. Road-paving machines. JAEGER MACHINE CO. June 28, 1949 [July 1. 1948], No. 17076/49. Class 107 A tractor vehicle 1 with means for feeding paving material on to the road, is connected to a screeding and levelling unit 64, 52 by pivoted arms 35, the front ends of which are supported by runners 36 riding on the surface to be covered while the rear ends are supported by the finishing leveller'52. riding on the newly-levelled material, relative vertical movement being permitted between the levelling unit, the vehicle and the runners, and a strike-off member 64 being supported on the arms 35 intermediate the front and rear supporting means. The forward end of the tractor is provided with a hopper 5 to which material is fed by a dump truck and conveyed by two endless belts 6 to two rotary spreading members 8 which feed the material in opposite directions across the road. The tractors 4, conveyers 6 and spreading members 8 are driven by an internal combustion engine 3 and can be separately controlled from either of two banks of control levers 32, 33. Drag-links 84 are pivoted to the tractor at 86 and to the screed member 64 and arms 35 at 82. The front ends 42 of the arms 35 are connected by links 39 to brackets 38 carried by the runners 36, and a screw jack 47 with lazy-tong arms 44 operated by a handle 49 at each side of the machine varies the height of each arm relative to the runners. The rear ends 58 of the arms 35 are universally jointed to and supported by the pan-shaped leveller 52 extending transversely from one arm 35 to the other. Forward tilt of the pan is prevented by turnbuckles 61. The screed 64 is arranged immediately behind the spreader members 8 and is described in Specification 660,623. Links 87 between the upper part of the screed and a bracket 91 on the tractor prevent the screed from tilting. The entire levelling and finishing unit is suspended from the tractor 1 by cables 99, 94 operated by pistons 98 so that it can be raised to inoperative position for transport. The screed 64 and levelling pan 52 are hollow and are supplied with heating medium from a heating unit 124 with a fan which forces the heating medium through baffled passages in the screed and then through a flexible duct 128 to the leveller, from which it issues through outlet slots at the ends. To form straight edges on the layer of material, floating side plates 133 are provided, slidable vertically in guides 134, 135 on the screed 64 and tractor 1 respectively. Initially the screed 64 is set to give the required thickness of layer by adjustment of the land wheels 49 and blocks are placed under each end of the screed to support it until the machine has moved forward and laid sufficient material for the pan 50 to rest upon the laid surface. If one runner 36 encounters a high spot the corresponding arm 35 will be raised, allowing the screed to feed more material, and as the machine proceeds the arm 35 will be lowered, laying a small amount of material directly over the high spot, so that discrepancies are averaged out.