Drainage tube

Claim 2

An essentially continuous subsoil strip or sheet drainage material comprising an internal supporting perforated or imperforate core strip or sheet of generally planar configuration upon which is disposed on both sides of the central plane, regularly spaced supporting projections having generally flat tops, each such projection having a length greater than one quarter of its spacing, said core covered or wrapped on all four non-continuous sides with a geotextile filter cloth or other permeable surfacing material which is not attached to the core.

Claim 3

The strip or sheet material of Claim I further characterized in that the assembled product can be tightly folded upon itself longitudinally or transversely, without damage or significant loss of water carrying capacity.

Claim 4

An essentially continuous subsoil drainage strip or sheet, perforated or imperforate comprising a core strip or sheet surfaced on all four non- continuous sides with permeable surfacing or filtering material wherein said core has the general configuration of a flat or distorted planar surface into which hollow tapered projections with generally flat tops have been formed or attached on a regular pattern on both sides of the central plane characterized in that the height of the projections from each side of the central plane is greater than one quarter of their closest spacing.

Claim 5

An essentially continuous subsoil drainage strip or sheet, perforated or imperforate comprising a core strip or sheet surfaced on all four non- continuous sides with permeable surfacing or filtering material wherein said core has the general configuration of a flat or distorted planar surface into which hollow tapered projections with generally flat tops have been formed or attached on a regular pattern on both sides of the central plane characterized in that the height of the projections from each side of the central plane is greater than one quarter of their closest spacing.

Claim 6

The strip or sheet material of Claim 3 wherein the permeable surfacing is bonded to the flat tops of the supporting core projections.

Claim 7

The strip or sheet material of Claim 3 wherein the permeable surfacing material is seamed to form a tube shaped cover over the core said surfacing material not being bonded or attached to the core at any point.

Claim 8

An essentially continuous sub-soil drainage strip or sheet comprising a perforated or imperforate core surfaced on all four noncontinuous sides with permeable surfacing or filtering material which is not attached to said core, and wherein said core has the general configuration of a distorted planar surface into which hollow generally tapered projections have been formed on a regular pattern so that each such core can be overlapped and nested upon another piece of itself so that end to end or intercepting joins can be made without substantially increasing the cross section area of the drain at the point of joining.

Claim 9

An essentially continuous sub-soil drainage strip or sheet comprising a perforated or imperforate core surfaced on all four noncontinuous sides with permeable surfacing or filtering material which is not attached to said core, and wherein said core has the general configuration of a distorted planar surface into which hollow generally tapered projections have been formed on a regular pattern so that each such core can be overlapped and nested upon another piece of itself so that end to end or intercepting joins can be made without substantially increasing the cross section area of the drain at the point of joining.

Claim 10

A continuous or noncontinuous sub-soil drainage strip or sheet, comprising a flat or distorted planar internally supporting core perforated or imperforated which has disposed upon it frequent projections capable of supporting an attached or nonattached flexible permeable surfacing material covering the flat sides and two opposing edges, against imposed soil loads, characterized in that the volume created by said internal supporting core is sufficiently large in transverse cross section and sufficiently unimpeded in the longitudinal flow direction, to enable a flow of water to be maintained within the drain strip which flow is impeded less than would be the case for water flowing in a cylindrical tube of cross sectional area of no less than one eighth and no more than one quarter of the cross section area of the said drain strip, at equivalent applied hydraulic pressure per unit length of drain pipe strip or sheet.

Claim 11

A continuous or noncontinuous sub-soil drainage strip or sheet, comprising a flat or distorted planar internally supporting core perforated or imperforated which has disposed upon it frequent projections capable of supporting an attached or nonattached flexible permeable surfacing material covering the flat sides and two opposing edges, against imposed soil loads, characterized in that the volume created by said internal supporting core is sufficiently large in transverse cross section and sufficiently unimpeded in the longitudinal flow direction, to enable a flow of water to be maintained within the drain strip which flow is impeded less than would be the case for water flowing in a cylindrical tube of cross sectional area of no less than one eighth and no more than one quarter of the cross section area of the said drain strip, at equivalent applied hydraulic pressure per unit length of drain pipe strip or sheet.

Claim 12

A sub-soil drain utilizing the strip or sheet material of Claim I characterized in that the drain strip is installed into a narrow but deep slit trench said strip installed on its edge with its wide faces lying in the vertical plane, further characterized in that no additional drainage tube or member is provided.

Claim 13

A sub-soil drain utilizing the strip or sheet of Claim 1 characterized in that the drain strip is cut into lengths and installed vertically downwards into the ground at regular intervals.

Claim 14

The strip or sheet of Claim 1 further characterized in that it is surfaced over part or all of its noncontinuous sides with impermeable or waterproof sheet material.