Torsion spring assembly with interlocking bushings

{
  "publication_number": "US5368283A",
  "country": "US",
  "kind": "A",
  "title": "Torsion spring assembly with interlocking bushings",
  "abstract": "A torsion spring assembly particularly adapted for use in closing the throttle valve of an automotive throttle body. The assembly includes two bushings formed with sleeves adapted to telescope into the end portions of a torsion spring. As an incident thereto, the bushings automatically interlock with one another to hold the bushings and the spring in assembled relation.",
  "claims": [
    "1. A torsion spring assembly comprising a coiled helical torsion spring having a plurality of coils including two end coils, first and second bushings having first and second generally cylindrical sleeves, respectively, telescoped into the end coils of said spring, first and second annular flanges formed integrally with and projecting radially outwardly from the outboard ends of the sleeves of said first and second bushings, respectively, and located adjacent said end coils, first means formed integrally with said first sleeve, and second means formed integrally with said second sleeve and directly engaging said means on said first sleeve interiorly of said plurality of coils to restrict rotational and axial movement of said first bushing relative to said second bushing.",
    "2. A torsion spring assembly as defined in claim 1 in which said means on said sleeves are shaped to interlock with a snap fit when the inboard ends of said sleeves are moved axially together.",
    "3. A torsion spring assembly as defined in claim 2 in which said means comprise first and second fingers projecting axially from said sleeves of said first and second bushings, respectively, and first and second grooves formed in the sleeves of said first and second bushings, respectively, and sized to receive said fingers with a snug but slidable fit.",
    "4. A torsion spring assembly as defined in claim 3 further including axially projecting means located near the center of the sleeve of each bushing and adapted to telescope into the sleeve of the other bushing.",
    "5. A torsion spring assembly as defined in claim 4 in which said axially projecting means of each bushing is shaped substantially as a half-cylinder.",
    "6. A torsion spring assembly as defined in claim 5 in which said first and second bushings are identical.",
    "7. A torsion spring assembly as defined in claim 3 including detents formed on each finger and formed in each groove.",
    "8. A torsion spring assembly as defined in claim 1 in which said first and second bushings are identical.",
    "9. A torsion spring assembly as defined in claim 1 in which said means on said sleeves are configured and dimensioned to permit axial movement of said first bushing relative to said second bushing through a limited range."
  ],
  "description_excerpt": "This invention relates to a torsion spring assembly having a torsion spring which, when loaded torsionally, exerts a biasing force on a member associated with the spring. The invention more particularly relates to a torsion spring of the type which is defined by a plurality of helically wound coils and by two radially projecting end tangs, the spring being loaded torsionally when one of the end tangs is moved angularly relative to the other end tang.\n\nWhile the spring assembly of the invention may be used in various applications, it is particularly suitable for use in effecting closure of the throttle valve of the throttle body or carburetor of an automotive internal combustion engine. A spring assembly of this general type is disclosed in Paggeot U.S. Pat. No. 4,828,235. In that assembly, two flanged bushings are telescoped into the end portions of the spring and mount the spring on the shaft of the throttle body. The end coils of the spring are of reduced diameter and are capable of tightly gripping the bushings in order to hold the bushings in assembled relation with the spring.\n\nBy virtue of the bushings, the coils of the spring of the Paggeot spring assembly are held in concentric relation with the shaft so that, when wound, the coils remain substantially uniform without substantial canting and without causing any substantial friction, sawing action or wear. While the spring assembly functions admirably in many applications, it does suffer some draw backs. In some cases, it is necessary that all of the spring coils be fully active in order to achieve a specified spring rate with acceptable endurance stress levels.",
  "cpc": [
    "F02D 11/04",
    "F02D 2009/0269"
  ],
  "ipc": [
    "F02D 11/04"
  ],
  "assignees": [
    "Precision Products Group Inc"
  ],
  "inventors": [
    "Robert J. Pavlin"
  ],
  "filing_date": "1993-08-05",
  "publication_date": "1994-11-29",
  "grant_date": "1994-11-29",
  "priority_date": "1993-08-05",
  "application_number": "US-10224393-A",
  "family_id": "22288876",
  "cited_by_count": 21,
  "citations": [
    "US3930380A",
    "US4597474A",
    "US4793444A",
    "US4838387A",
    "US4828235A"
  ]
}