Patent GB-1276591-A (GB)
Title: Improvements in or relating to the cleaning of sewer pipes and catch basins
IPC: E03F9/00
Filed: 1970-06-16
Abstract: 1276591 Cleaning pipes MYERS SHERMAN CO 16 June 1970 [12 Sept 1969] 29152/70 Heading F2N [Also in Division E1] A sewer pipe 41 is flushed and cleaned by means of a single vehicle which is provided with both a depending conduit 26, for sucking the contents of a catch basin 40 into a tank 13, and a hose 28 with a self-propelling nozzle 29 on its leading end, the nozzle being constructed such that when water is forced through rearwardly directed jets in the nozzle by a pump 60, Fig. 6, the nozzle is propelled forwardly through the sewer pipe, drawing the hose from a reel 27. The pump 60 is preferably a reciprocating pump comprising a tandem piston assembly, as shown, one piston 67 being a motor piston driven alternately in opposite directions by pressurized oil from an hydraulic pump 85 on a power take-off shaft of the vehicle, reversal of movement of the piston assembly being effected by an electrically-operated primary shuttle valve 88 and a secondary fluid-operated shuttle valve 87 controlled by the primary shuttle valve, control of operation of the primary shuttle valve being obtained from the movement of the piston 67 by way of a control rod 104 operating a change-over switch 90, lost-motion being provided as necessary between the rod 104 and the piston 67. The pump piston, which is connected to motor piston 67 by a rod 66, operates in a cylinder 63 which has inlets 74, 75 and outlets 77, 78 connected via non-return valves 82 to water supply tank 12 and hose 28, respectively, so that the pump is double-acting. The varying rate of flow produced by such a pump is said to be beneficial in causing the nozzle 29 to jump and thus force its way past obstructions in the sewer pipe. In operation, the nozzle 29 is first lowered into the catch basin 40 and is guided into correct position for entering the sewer pipe by manipulating a tool 42, which has a curved guide portion 44, with a holder for the nozzle, and a plate 46 adapted to enter the sewer pipe 41 when the nozzle is in the correct position. Pump 85 is now driven to cause water from the tank 12 to be pumped by the reciprocating pump 60 into the hose 28, whereby water issues rearwardly from outwardly inclined jet orifices in the rear of the enlarged tip of the nozzle 29, causing the nozzle to propel itself along the sewer pipe for a desired distance. The suction conduit 26 is then lowered, after fitting suitable extensions 48 to enable it to reach the bottom of the catch basin, and an auxiliary motor is started up which drives a fan (Fig. 9) to evacuate the tank 13. At the same time hose reel 27 is connected to a power takeoff of the vehicle so that the hose 28 is wound back, in spite of the fact that water continues to issue from the nozzle 29. This flushes the debris D from the sewer pipe into the catch basin, from which it is sucked up the conduit 26 into the tank 13. A filter cap 47 may be fitted to other sewer pipes communicating with the catch basin to prevent debris entering them. After the cleaning and flushing operation has been completed, the liquid content of the tank 13 is returned to the catch basin by connecting a hose 50 to the outlet of a valve 49 leading from a filtered outlet of the tank 13, and opening the valve. This enables the vehicle to be used several times for successive flushing and cleaning operations, after which the solid residue in tank 13 is dumped by tipping the tank 13 by means of an hydraulic ram (Fig. 5, not shown), after releasing a rear door catch 17.