GB822315A - Improvements in or relating to apparatus for producing mole drains - Google Patents

Abstract

822,315. Drainage. WOOD, E. April 22, 1958 [Jan. 29, 1957], No. 3064/57. Class 33. [Also in Group X] In a method of strengthening a mole drain, the drain is partially or completely lined with cement which is applied to the walls of the drain by ejecting it from the expander of a mole drain plough in the form of a powder as the drain is being formed. A spray of water is also ejected from the expander to dampen the cement. The floor of the drain may be left unlined and the strengthening material pressed against the earth walls of the drain by a former. The cement may include a quick set additive. A suitable cement is a mixture of half by weight of high aluminous cement, the balance being portland cement, with or without the additive. A quantity of organic matter may be mixed with the cement which will rot away when embedded in the earth, and thus leave a large number of small holes through the lining. Apparatus for carrying out the method comprises a mole-drain plough having apparatus for ejecting cement in the form of a powder from the expander 74. From a hopper 58 to the expander 74 an auger 92 in a feed-box 88 delivers and meters cement blown by an air compressor 62 through a pipe 86, housed in a recess 67 in the rear of the plough blade 66, and through shaped outlet 84 between the expander 74 and a conical member 80 formed on a former 78 which presses the dampened cement against the earth walls. A pipe 94, in which is connected the pump 64, also in the recess 67, leads from a water tank 56 through the expander 74 into the former 78, and through a slot in the pipe wall water escapes into the cone 80 and then through holes 98 in radial jets, not required, however, in very wet ground. The plough preferably incorporates an automatic depth control system for the bar 70. According to the Provisional Specification, the air compressor may be driven from the power-take-off shaft of the tractor drawing the plough or by a separate engine, whereas the flow of cement and / or water may be controlled by valves on the hopper and tank pipes whilst the plough is in the earth, and may be arranged so that the lining is thicker at the bottom than the top of the drain.