Load transfer apparatus for cast-in-place concrete slabs

{
  "publication_number": "US8465222B1",
  "country": "US",
  "kind": "B1",
  "title": "Load transfer apparatus for cast-in-place concrete slabs",
  "abstract": "A tapered dowel bar for transferring loads across a joint between adjacent concrete slabs is disclosed. The dowel tapers from one relatively wide cross section into one or more relatively narrow ends. The shape of the dowel is optimized to provide the highest amount of steel along the joint where the loads are highest. The tapered dowel is embedded in one or both sides into a socket assembly that connects the dowel to essentially planar top and bottom surfaces of a pocket former embedded in the concrete. The load transfer assembly restricts any relative vertical displacement between the first and second slabs. The socket assembly embedded in the pocket former or equipped with compressible material accommodates relative horizontal movement between adjacent slabs in directions essentially parallel and perpendicular to the joint.",
  "claims": [
    "1. A system for load transfer across a joint between adjacent cast-in-place concrete slabs, comprising: a first cast-in-place concrete slab; a second cast-in-place concrete slab; a joint separating the first and second concrete slabs, wherein said joint is a plane oriented essentially perpendicular to a substantially planar upper surface of the first slab, and a longitudinal axis of said joint is formed by an intersection of said joint with the upper surface of the first slab; a dowel bar for load transfer, with a longitudinal axis defined essentially perpendicular to the surface of the joint, and a cross section measured essentially perpendicular to said longitudinal axis, wherein the dowel has a predetermined length measured essentially perpendicular to said joint; at least one socket assembly having essentially planar upper and lower surfaces; at least one pocket former having means for positioning the socket assembly during installation; whereby the load transfer assembly restricts relative movement between the first and second slabs in a direction substantially perpendicular to the upper surface of the first slab; provides unrestrained joint opening as the first and second slabs move away from each other in a direction substantially perpendicular to the joint; and allows for relative slab displacement in a direction substantially parallel to the longitudinal axis of the joint; whereby the first end of said dowel bar protrudes into the first slab, and the second end protrudes into the second slab such that the dowel transfers a load between the first and second slabs, the load being applied to either slab.",
    "2. The system of claim 1, wherein said dowel bar has an essentially circular cross section, and the corresponding diameter of said cross section is measured in a direction essentially parallel to said joint.",
    "3. The system of claim 1, wherein said dowel tapers from one relatively wide cross section into one relatively narrow cross section, the taper being a generally progressive reduction of said cross section of said dowel bar over a predetermined portion of said length of said dowel.",
    "4. The system of claim 3, wherein said cross section of said tapered dowel is circular, and the corresponding diameter of said cross section is measured in a direction essentially parallel to the joint.",
    "5. The system of claim 3, wherein said dowel essentially tapers from the relatively wide cross-section into at least one substantially pointed end.",
    "6. The system of claim 3, wherein said dowel has essentially one said tapered portion, along said length of said dowel.",
    "7. The system of claim 3, wherein said dowel has essentially two said tapered portions, along said length of said dowel.",
    "8. The system of claim 7, wherein said dowel tapers on both sides of the joint, with the relatively wide cross section essentially positioned along the joint and the relatively narrow ends within the first and second concrete slabs, and the dowel tapers progressively along each side of the joint.",
    "9. The system of claim 8, wherein said taper of said dowel is different on each side of the joint.",
    "10. The system of claim 1, wherein a plurality of compressible fins are used along the pocket former in order to adequately position said socket assembly within said pocket former.",
    "11. An apparatus for load transfer across a joint between a first cast-in-place concrete slab and a second cast-in-place concrete slab, wherein said joint is defined by a surface essentially perpendicular to a substantially planar upper surface of the first slab, and longitudinal axis of said joint is formed by an intersection of said joint with the upper surface of the first slab; the apparatus comprising: a first cast-in-place concrete slab; a second cast-in-place concrete slab; a dowel bar for load transfer, with a longitudinal axis defined essentially perpendicular to the surface of said joint, and a cross section measured essentially perpendicular to said longitudinal axis, wherein said dowel has a predetermined length measured essentially perpendicular to said joint; at least one socket assembly having essentially planar upper and lower surfaces; a compressible material essentially attached along the external vertical surfaces of the casing of the socket assembly; whereby said dowel restricts relative movement between the first and second slabs in a direction substantially perpendicular to the upper surface of the first slab; maintains substantially adequate load transfer across the joint, provides unrestrained joint opening as the first and second slab move away from each other in a direction substantially perpendicular to the joint; and allows for relative displacement in a direction substantially parallel to the longitudinal axis.",
    "12. The system of claim 11, wherein said dowel bar has an essentially circular cross section, and the corresponding diameter of said cross section is measured in a direction essentially parallel to said joint.",
    "13. The system of claim 11, wherein said dowel tapers from one relatively wide cross section into one relatively narrow cross section, the taper being a generally progressive reduction of said cross section of said dowel bar over a predetermined portion of said length of said dowel.",
    "14. The system of claim 13, wherein said cross section of said tapered dowel is circular, and the corresponding diameter of said cross section is measured in a direction essentially parallel to the joint.",
    "15. The system of claim 13, wherein said dowel essentially tapers from the relatively wide cross-section into at least one substantially pointed end.",
    "16. The system of claim 13, wherein said dowel has essentially one said tapered portion, along said length of said dowel.",
    "17. The system of claim 3, wherein said dowel has essentially one said tapered portion, along said length of said dowel.",
    "18. The system of claim 17, wherein the dowel tapers on both sides of the joint, with the relatively wide cross section essentially positioned along the joint and the relatively narrow ends within the first and second concrete slabs, and the dowel tapers progressively along each side of the joint.",
    "19. The system of claim 18, wherein said taper of said dowel is different on each side of the joint.",
    "20. The system of claim 11, wherein a plurality of compressible fins are used along the pocket former in order to adequately position the socket assembly within the pocket former."
  ],
  "description_excerpt": "non-applicable\n\nnon-applicable\n\n0,232,697 A1 October 2005 Brinkman 0,204,558 A1 September 2007 Carroll 0,014,018 A1 January 2008 Boxall et al. 0,054,858 A1 March 2010 Mayo et al. 2,096,702 A October 1937 Yeoman 2,164,590 A July 1939 Oates 2,255,599 A September 1941 Olmsted 2,500,262 A March 1950 Parrott 6,171,016 B1 January 2001 Pauls et al. 6,386,774 B1 May 2002 Carpenter 6,447,203 B1 September 2002 Ruiz et al. 7,481,031 B2 January 2009 Boxall et al. 7,716,890 B2 May 2010 Boxall et al. 3,104,600 A September 1963 White 4,733,513 A March 1988 Schrader et al. 4,996,816 A March 1991 Wiebe 5,797,231 A August 1998 Kramer 6,019,546 A February 2000 Ruiz 6,145,262 A November 2000 Schrader et al. 6,354,760 B1 March 2002 Boxall et al. 7,201,535 B2 April 2007 Kramer 7,338,230 B2 March 2008 Shaw et al. 7,441,985 B2 October 2008 Kelly et al. 7,481,031 B2 January 2009 Boxall et al. 7,637,689 B2 December 2009 Boxall et al. 7,716,890 B2 May 2010 Boxall et al. 7,874,762 B2 January 2011 Shaw et al.\n\nDE 726829 September 1942 EP 0059171 September 1982 EP 0328484 A1 August 1989 GB 2285641 A July 1995\n\n1. Field of the Invention\n\nThis invention relates generally to an assembly for transferring loads between adjacent cast-in-place slabs, and more particularly, to an improved system for transferring a load across a joint between a first and a second slab, the load being applied to either slab.\n\n2. Related Art\n\nTypical floors in industrial buildings, roads, driveways, sidewalks, and other, are constructed using concrete.",
  "cpc": [
    "E01C 11/14"
  ],
  "ipc": [
    "E01C 11/14"
  ],
  "inventors": [
    "Ziad Ghauch",
    "Hadi Ghauch"
  ],
  "filing_date": "2012-03-19",
  "publication_date": "2013-06-18",
  "grant_date": "2013-06-18",
  "priority_date": "2012-03-19",
  "application_number": "US-201213424215-A",
  "family_id": "48578086",
  "cited_by_count": 15,
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}