Apparatus for applying filter to a drainage tubing

摘要

Apparatus and method for applying a filter sleeve to a continuous length of drainage tubing. The filter sleeve is gathered and packed endwise on a tubular mandrel. The mandrel is received within a dispensing canister mounted on trench-digging and drain-laying equipment between a supply of drainage tubing and a trench plow and laying boot assembly. The drainage tubing passes through the mandrel as it progresses from the supply to the laying boot which installs it in the trench, and one end of the filter sleeve is connected to the tubing whenever filter covering is desired. When so connected, the filter sleeve is continuously pulled by the tubing off the mandrel and about said tubing, through a feed controller in the form of an annular diaphragm at the exit end of the mandrel.