Duct liners

• US 6,148,867 A
• Filed: 04/09/1999
• Issued: 11/21/2000
• Est. Priority Date: 09/14/1995
• Status: Expired due to Term

• Current Assignee: Johns Manville International, Inc. (Berkshire Hathaway Incorporated)
• Original Assignee: Johns Manville International, Inc. (Berkshire Hathaway Incorporated)
• Inventors: Schakel, Eric G., Matthews, Kent R.
• Primary Examiner(s): BRINSON, PATRICK F
• Application Number:
  US09/293,469
• Time in Patent Office: 592 Days
• Field of Search: 138/149, 138/151, 138/156
• US Class Current: 138/149
• CPC Class Codes: B32B 1/08 Tubular products
• CPC Class Codes: B32B 15/04 comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a bituminous or tarry layer B32B11/08; next to a water-setting substance layer B32B13/06; next to a glass layer B32B17/061; next to a cellulosic plastic layer B32B23/042
• CPC Class Codes: B32B 2597/00 Tubular articles, e.g. hoses, pipes
• CPC Class Codes: B32B 3/30 characterised by a layer formed with recesses or projections, e.g. hollows, grooves, protuberances, ribs apertured layer B32B3/266; layer with cavities or internal voids B32B3/26
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: E04C 2/328 slightly bowed or folded panels not otherwise provided for
• CPC Class Codes: F16L 59/02 Shape or form of insulating materials, with or without coverings integral with the insulating materials
• CPC Class Codes: F16L 59/026 Mattresses, mats, blankets or the like
• CPC Class Codes: F16L 59/14 Arrangements for the insulation of pipes or pipe systems F16L59/02 - F16L59/12 take precedence
• CPC Class Codes: F16L 59/147 the insulation being located inwardly of the outer surface of the pipe
• CPC Class Codes: F24F 13/0245 Manufacturing or assembly of air ducts; Methods therefor
• CPC Class Codes: F24F 13/0263 Insulation for air ducts
• CPC Class Codes: F24F 13/0281 Multilayer duct
• CPC Class Codes: Y10T 29/49435 Flexible conduit or fitting therefor
• CPC Class Codes: Y10T 29/49623 Static structure, e.g., a building component

Abstract

Ducts are formed from rigid or semi-rigid insulation boards by forming a plurality of longitudinally extending, spaced apart, parallel kerfs in a first major surface of each of the insulation boards which is adapted to be the interior surface of the duct. When the insulation board is formed into a duct of the preselected dimensions, the shoulders of the kerfs adjoining the interior surface of the duct abut and, preferably, the insulation material in the shoulders of the kerfs is compressed. The flexibility of the insulation boards, in the direction of the widths of the insulation boards, is controlled by increasing the depths and/or the widths of the kerfs and/or decreasing the spacing between the kerfs to make the insulation board more flexible and by decreasing the depths and/or the widths of the kerfs and/or increasing the spacing between the kerfs to make the insulation board less flexible.

Claims

1. A kerfed insulation board for forming a duct of a preselected transverse dimensions and cross section comprising:

an insulation board having a first major surface adapted to be an interior surface of a duct formed from said insulation board and a second major surface adapted to be an outer surface of a duct formed from said insulation board;

said insulation board having a length adapted to extend parallel to a longitudinal centerline of a duct formed from said insulation board, a width and a thickness;

kerfs in said first major surface of said insulation board for making said insulation board flexible in a direction of said width of said insulation board and foldable into a tubular configuration of preselected transverse dimensions and cross section;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

each of said kerfs having sidewalls which extend from a kerf base portion adjacent but spaced inwardly from said second major surface of said insulation board to said first major surface of said insulation board;

each of said kerfs having shoulder portions adjoining said first major surface of said insulation board; and

each of said kerfs having a width at said first major surface of said insulation board;

said width of said kerfs at said first major surface of said insulation board pressing said shoulder portions of said kerfs into abutment with said insulation in said shoulder portions being in compression, when said insulation board is formed into a duct of said preselected transverse dimensions and cross section, to retain said insulation board in said preselected transverse cross section with no exposure of the kerf sidewalls at the interior surface of the duct and with any loose fibers or dust from said kerf sidewalls being confined within said kerfs.

2. The kerfed insulation board according to claim 1, wherein:

said sidewalls of each of said kerfs diverge with respect to each other from said kerf base portion to said first major surface of said insulation board.

3. The kerfed insulation board according to claim 1, wherein:

each of said kerfs is formed with a generally vee-shaped transverse cross section.

4. The kerfed insulation board according to claim 1, wherein:

said thickness of said insulation board is between about one inch and four inches and said base portion of each of said kerfs is spaced from said second major surface of said insulation board between about one quarter and about one half of an inch.

5. A duct comprising:

an insulation board having a first major surface forming an interior surface of a duct and a second major surface forming an outer surface of said duct;

said insulation board having a length extending parallel to a longitudinal centerline of said duct, a width and a thickness;

kerfs in said first major surface of said insulation board;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

said insulation board being folded into a tubular configuration of preselected transverse dimensions and cross section; and

each of said kerfs having shoulders adjoining said first major surface which abut each other with insulation material in said shoulder portions being in compression to retain said insulation board in said preselected transverse cross section with no exposure of the kerf sidewalls at the interior surf ace of the duct and with any loose fibers or dust from said kerf sidewalls confined within said kerfs.

6. The duct according to claim 5, wherein:

said thickness of said insulation board is between about one inch and about four inches and said kerfs have a base portion spaced from said second major surface of said insulation board between about one quarter and about one half of an inch.

7. A kerfed insulation board for forming a duct of a preselected transverse dimensions and cross section comprising:

an insulation board having a first major surface adapted to be an interior surface of a duct formed from said insulation board and a second major surface adapted to be an outer surface of a duct formed from said insulation board;

said insulation board having a length adapted to extend parallel to a longitudinal centerline of a duct formed from said insulation board, a width and a thickness; and

kerfs in said first major surface of said insulation board for making said insulation board flexible in a direction of said width of said insulation board and foldable into a tubular configuration of preselected transverse dimensions and cross section;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

each of said kerfs having sidewalls which extend from a kerf base portion adjacent but spaced inwardly from said second major surface of said insulation board to said first major surface of said insulation board;

each of said kerfs having a stepped transverse cross section with said sidewalls of each of said kerfs having a plurality of portions, extending substantially perpendicular to said first major surface of said insulation board, which are joined by portions extending at an angle to said first major surface of said insulation board;

each of said kerfs having shoulder portions adjoining said first major surface of said insulation board; and

each of said kerfs having a width at said first major surface of said insulation board such that, when said insulation board is formed into a duct of said preselected transverse dimensions and cross section, said shoulder portions of said kerfs abut and insulation material in said shoulder portions of said kerfs is placed in compression.

8. A kerfed insulation board for forming a duct of a preselected transverse dimensions and cross section comprising:

an insulation board having a first major surface adapted to be an interior surface of a duct formed from said insulation board and a second major surface adapted to be an outer surface of a duct formed from said insulation board;

said insulation board having a length adapted to extend parallel to a longitudinal centerline of a duct formed from said insulation board, a width and a thickness;

said insulation board comprising fibrous insulation having a density between about 2.4 and about 4.5 pounds per cubic foot; and

kerfs in said first major surface of said insulation board for making said insulation board flexible in a direction of said width of said insulation board and foldable into a tubular configuration of preselected transverse dimensions and cross section;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

each of said kerfs having sidewalls which extend from a kerf base portion adjacent but spaced inwardly from said second major surface of said insulation board to said first major surface of said insulation board;

each of said kerfs having shoulder portions adjoining said first major surface of said insulation board; and

each of said kerfs having a width at said first major surface of said insulation board such that, when said insulation board is formed into a duct of said preselected transverse dimensions and cross section, said shoulder portions of said kerfs abut and said fibrous insulation in said shoulder portions of said kerfs is placed in compression.

9. A kerfed insulation board for forming a duct of a preselected transverse dimensions and cross section comprising:

an insulation board having a first major surface adapted to be an interior surface of a duct formed from said insulation board and a second major surface adapted to be an outer surface of a duct formed from said insulation board;

said insulation board having a length adapted to extend parallel to a longitudinal centerline of a duct formed from said insulation board, a width and a thickness;

said insulation board comprising a cellular foam insulation having a density between about 0.5 and about 2.0 pounds per cubic foot; and

kerfs in said first major surface of said insulation board for making said insulation board flexible in a direction of said width of said insulation board and foldable into a tubular configuration of preselected transverse dimensions and cross section;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

each of said kerfs having sidewalls which extend from a kerf base portion adjacent but spaced inwardly from said second major surface of said insulation board to said first major surface of said insulation board;

each of said kerfs having shoulder portions adjoining said first major surface of said insulation board; and

each of said kerfs having a width at said first major surface of said insulation board such that, when said insulation board is formed into a duct of said preselected transverse dimensions and cross section, said shoulder portions of said kerfs abut and said foam insulation in said shoulder portions of said kerfs is placed in compression.

10. A duct comprising:

an insulation board having a first major surface forming an interior surface of a duct and a second major surface forming an outer surface of said duct;

said insulation board having a length extending parallel to a longitudinal centerline of said duct, a width and a thickness;

kerfs in said first major surface of said insulation board;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

each of said kerfs having shoulders adjoining said first major surface which abut each other with insulation material in said shoulder portions being in compression; and

said duct being a liner enclosed within a tubular metal shell.

11. A duct comprising:

an insulation board having a first major surface forming an interior surface of a duct and a second major surface forming an outer surface of said duct;

said insulation board having a length extending parallel to a longitudinal centerline of said duct, a width and a thickness;

said insulation board comprising a fibrous insulation having a density between about 2.4 and about 4.5 pounds per cubic foot; and

kerfs in said first major surface of said insulation board;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

each of said kerfs having shoulders adjoining said first major surface which abut each other with said fibrous insulation in said shoulder portions being in compression.

12. A duct comprising:

an insulation board having a first major surface forming an interior surface of a duct and a second major surface forming an outer surface of said duct;

said insulation board having a length extending parallel to a longitudinal centerline of said duct, a width and a thickness;

said insulation board comprising a cellular foam insulation having a density between about 0.5 and about 2.0 pounds per cubic foot; and

kerfs in said first major surface of said insulation board;

each of said kerfs having a depth;

each of said kerfs extending parallel with respect to and being spaced from other of said kerfs;

each of said kerfs extending said length of said insulation board;

each of said kerfs having shoulders adjoining said first major surface which abut each other with said foam insulation in said shoulder portions being in compression.