Method and apparatus for longitudinally reinforcing continuously generated plastic pipe

DETAILED DESCRIPTION It is an object of the invention to provide a new and improved method and apparatus for producing longitudinally reinforced continuously generated resin-impregnated fiber plastic pipe.
It is also an object to provide a method and apparatus for longitudinally reinforcing plastic pipe which uses the same type of fiber elements that are wound circumferentially onto the pipe.
It is additionally an object to provide a method and apparatus for longitudinally reinforcing plastic pipe which allows close control of the amount of longitudinal reinforcing fiber elements applied to the pipe.
It is a further object to provide a method and apparatus for longitudinally reinforcing plastic pipe from fixed stations, thereby enabling replenishment of the supply of reinforcing fiber elements without stopping the operation.
Briefly stated, in a method and apparatus for longitudinally reinforcing continuously generated plastic pipe according to the invention, a plurality of fiber elements are wound circumferentially onto the pipe being generated, and continuous fiber elements are deposited longitudinally onto the surface of the pipe in the nip formed between the surface of the pipe and the fiber elements being circumferentially wound onto the pipe.
In accordance with more specific aspects, the circumferential fiber elements are first passed through a resin bath and then over a pair of rollers contacting the surface of the pipe being generated.
Longitudinal reinforcing fiber elements are deposited onto the surface of the pipe in the nip in a reciprocating pattern from a supply tube having its outlet, which is adjacent to the nip, swung in an arc substantially parallel to the longitudinal axis of the pipe.
The rollers guide the fibers from the supply tube lengthwise onto the pipe.
The fibers being circumferentially wound onto the pipe hold the longitudinal fibers in place against the pipe surface and coat them with resin.
These, and other objects, advantages, features and improved results provided by the invention will become apparent from the following detailed description and drawings of the preferred embodiments of the invention