Patent GB-627319-A (GB)
Title: Motor vehicle for spraying tar or other liquid material on road or other surfaces
IPC: E01C19/17
Filed: 1946-11-22
Abstract: 627,319. Tank vehicles for tar spraying. SCAMMELL LORRIES, Ltd., HUGH, P. G., and HALL, W. F. Nov. 22, 1946, No. 34605. [Class 108 (i)] [Also in Group XXVI] A motor vehicle for spraying tar or other liquid on roads and other surfaces comprises a tank mounted on the vehicle or arranged as a trailer provided with heating appliances and a pump or pumps for charging, discharging or spraying the liquid and an electric generator driven by the power unit of the vehicle supplying a regulated output for driving the pump motors and for electric heaters. The heaters can be coupled to a mains supply when the vehicle is in a garage, the mains socket being provided with a safety device to cut out the electrical control devices. In Fig. 1, the tank 3 is mounted on a chassis 2 and is lagged, the tank being slightly inclined towards the rear. The engine 20 drives an air-cooled electric generator 25 through a chain or gear-drive 21, torquelimiting coupling 22, shafts 23, 24 and flexible couplings. The rear end of the tank is provided with a compartment closed by a door 8, in which is installed removable, thermostaticallycontrolled, electric immersion heaters 4, Fig. 3, filling or control pump 5 with motor 6 and a control panel 7. Tar may be fed into the tank through a filter in a top manhole and a vent pipe from the filter passes through the tank to an external pipe to catch any overflow when filling the tank. The pump 5 is immersed in the tar in the tank and is of the positive delivery type having rotary double helical gears and draws its supply from a sump in the bottom of the tank, the sump being provided with a removable base and sludge cock. The tarspraying apparatus may be of the kind described in Specification 627,320, [Group X]. Delivery from the pump is made through a branch 66 and flexible hose and one or more valves 67 may be arranged to carry out the following functions : filling the tank from an outside source; pumping the tar from point to point byepassing the vehicle tank; circulate the tar from the tank through a spray bar 10 and back to the tank; deliver specified quantities from the tank to the nozzles: deliver a free flow quantity of tar to a hand spraying device as described in Specification 627,320; discharge the residue of the tar left in the tank to an outside storage tank through an external hose. The spray bar unit 10 may be built up in sections, the end portions being detachable to vary the width of spray. The jets or nozzles 12 produce a divergent spray which may overlap and the control cocks for each nozzle are linked by a bar 13 operated by a hand lever 14, the cocks being detachable from the bar 13 so that some may be disconnected when required. A deflector plate may be placed between any two nozzles to give an increased local supply of tar. In the wiring diagram, Fig. 5, the generator 25 is connected through a junction box 30 with an Isenthal vibrating regulator 31 driven by a motor 32, the field circuit 33 and ballast resistor 34 being connected in the circuit. The immersion heaters 4 are connected across the main output leads 36 and are arranged as three main heaters and two supplementary heaters controlled by switches 37, 39, the operating coils 38, 40 of which include thermostat switches 43, 42. The mains supply is connected to a socket in a lidded box 52 provided with a pair of contacts 56 bridged by a spring-loaded contact member 55 mounted on the hinged lid 53, the socket having separate plugs 58, 59 and 60, which can be used to connect, 5, 3 or 2 heaters to the mains. The electric motor 6 for driving the pump 5 includes in the circuit a booster generator 45 and booster motor 46, but these are only required when it is desired to regulate the speed of the pump motor over a very wide range. The tar pump motor 6 is of the shunt type and .is controlled to operate in synchronism with the speed of the vehicle as described in Specification 627,321, [Group XXXVII]. Specification 627,318 also is referred to.