Abstract: The conduit includes a top wall (A) and a base (B). The top wall A has an apex area (10) which is connected with a first corrugated side wall (12) and a second corrugated side wall (32). The side walls having alternating peaks (22, 42) and valleys (24, 44). The peaks have apex ends (26, 46) which are disposed closely adjacent each other at the apex area to define a hinge region therebetween. Disposed along the apex area and on the side wall peaks are a plurality of outward projecting dimples (70, 72, 74) which are severable by a tangentially disposed knife blade to form a plurality of apertures (50, 52, 54). The base B is a flexible sheet of plastic mesh material.

Abstract: The specification discloses an apparatus and method for concurrently manufacturing at least two semiround tubing structures. An extruder including plasticizing means for a plurality of plastic resins extrudes semiround and linear strips of plastic material in generally two back to back D-shaped sleeves. Between the D-shaped sleeves, a strip of adhesively non-compatible material is extruded so that the D-shaped sleeves may be separated. The rounded portions of the D-shaped sleeves are molded in a continuous blow molding arrangement to form the top wall of the semiround tubing. The tubing is cooled, and the two semiround tubing lengths separated from the adhesively non-compatible strip inbetween. Optionally, the base of the semiround tubing may be perforated. The two lengths of semiround tubing are folded with the base inside the top wall and coiled into large reels.

Abstract: A foldable conduit has a generally parabolic arched portion and a flat base. The arched portion comprises a pair of corrugated side walls which are connected with a hinge. The corrugations comprise alternating peak portions and valley portions. Each peak portion comprises a pair of generally vertical corrugation walls and a top wall connected with the corrugation walls. The top wall has a pair of ribs, each adjacent one of the pair of corrugation walls. Between the ribs is a recessed area. The ribs and recessed area are arcuate and generally undulating in cross section. The valley portion comprises an arcuate valley wall connected with the corrugation walls of adjacent peak portions. The flat base is a flexible sheet which may be perforated to permit fluid ingress and egress. The hinge and flexible base allow the side walls to be folded together with the base folded in between for more compact shipment.

Abstract: Disclosed is a foldable arched conduit suitable for use as drain tubing, culverts and the like. The conduit has the cross section of a parabolic arch with a flat base. The arched portion of the conduit comprises a pair of rigid corrugated plastic walls jointed at the apex area by a hinge. The base is constructed from a flexible sheet material which may contain apertures for liquid ingress and egress. For shipment, the rigid walls are folded inward about the hinge with the flexible sheet being folded between the rigid walls in order to present a generally flat configuration. After folding, the conduit may be conveniently rolled or length placed in parallel stacks for reducing the storage and/or shipping space required. At installation, the conduit may be unrolled along the installation site and then caused to expand into its unfolded shape.

Abstract: A plow assembly and method useful for burying an elongated flexible member at a predetermined depth beneath ground level. The arrangement utilizes a frame assembly adapted to be pulled by a tractor type vehicle and which frame assembly has a vertically-extending plow support unit. A dynamic plow unit is mounted at the lower end of the plow support unit and includes a generally horizontal base. The forward end of the plow unit includes a plow nose portion having an inclined top surface. The top of the plow unit is defined by a plate member having an upper surface which extends rearwardly from the nose generally parallel to the base. The plate member is mounted about a transverse axis closely adjacent the nose portion for pivotal oscillating movement by hydraulic cylinder means. Such oscillation is between a first position generally parallel to the plow unit base and a second position spaced angularly upward therefrom.