Viscoelastic damper

{
  "publication_number": "US3842945A",
  "country": "US",
  "kind": "A",
  "title": "Viscoelastic damper",
  "abstract": "A viscoelastic damper particularly suited for use in a rotor system of a helicopter or the like is provided to damp lead-lag motion of the blade relative to the rotor hub. An elongate body of viscoelastic material has an inner plate embedded centrally therein and extending longitudinally thereof. Separate elongate nonextensible outer plates are secured to opposite sides of the body in spaced apart parallel relation to the inner plate. Means rigidly interconnect the outer plates for simultaneous movement relative to the inner plate and preload the body between the plate in compression. Spaced pivotal connection means are carried by the inner plate and outer plates, respectively, to effect relative movement therebetween and shearing of the body of viscoelastic material.",
  "claims": [
    "1. A viscoelastic damper comprising an elongate body of viscoelastic material, an elongate nonextensible inner plate embedded centrally within and bonded to said body and extending longitudinally thereof substantially the entire length thereof, said inner plate having one end extending outwardly beyond said body, pivotal connection means carried by said one end of said inner plate, separate elongate nonextensible outer plates bonded to opposite sides of said body substantially the entire length thereof in spaced apart parallel relation to each other and to said inner plate, the elongate axis of said plates being oriented in the same direction as that of said body, means rigidly interconnecting said outer plates for simultaneous movement relative to said inner plate and preloading said body between said inner and outer plates in compression perpendicular to its longitudinal axis, said outer plate interconnecting means being spaced from said body and inner plate means, and pivotal connection means carried by said outer plates, the axis of each of said pivotal connection means being perpendicular to the longitudinal axis of said damper.",
    "2. A viscoelastic damper, as set forth in claim 1, wherein said outer plates rigid interconnecting means comprises rigid spacer means disposed between said outer plates in spaced relation from said body and inner plate means, and means rigidly interconnecting said outer plates with said spacer means for preloading said body between said inner and outer plates in compression.",
    "3. A viscoelastic damper, as set forth in claim 1, wherein said outer plates pivotal connection means is carried substantially half way between opposite ends of said outer plates.",
    "4. A viscoelastic damper, as set forth in claim 2, wherein said inner plate and at least one of said outer plates have proximate mating convex and concave surfaces extending transversely thereof to resist relative transverse movement between said inner plate and at least one outer plate.",
    "5. A viscoelastic damper, as set forth in claim 4, wherein said outer plates pivotal connection means is carried by the end of said outer plates remote from said inner plate pivotal connection means."
  ],
  "cpc": [
    "B64C 27/51",
    "B60G 2206/11"
  ],
  "ipc": [
    "B64C 27/51"
  ],
  "inventors": [
    "J Potter"
  ],
  "filing_date": "1973-06-28",
  "publication_date": "1974-10-22",
  "grant_date": "1974-10-22",
  "priority_date": "1971-05-13",
  "application_number": "US-37459173-A",
  "family_id": "26840561",
  "cited_by_count": 32
}