Electron microscope

{
  "publication_number": "US3814356A",
  "country": "US",
  "kind": "A",
  "title": "Electron microscope",
  "abstract": "A vibration eliminating support system for a sensitive instrument. The support system includes a bearing which supports the instrument in pendulum fashion such that external vibrations and movement of the support are transformed to long period swinging motion of the instrument. This prevents relative movement of the parts of the instrument with the result that vibrations and shock have no effect on the accuracy of the instrument. The support system has particular utility for vibration isolation of a rigid column of an electron microscope which is suspended on the bearings for pivotal movement. Advantageously, the bearings are air bearings to maintain friction of the bearing surfaces at an absolute minimum.",
  "claims": [
    "1. An improved vibration eliminating support system for eliminating the transmission of vibrations from a support to an electron microscope mounted on the support comprising in combination a support frame; a rigid microscope column; essentially friction free bearing means on the frame; and mounting means mounting said microscope column on the bearing means for free swinging movement in pendulum fashion on said frame, so that vibrations of said support frame caused by external forces are converted to slow swinging motion of the pendulum supported microscope column.",
    "2. A support system according to claim 1 wherein said bearing means includes an upwardly facing concave surface on said frame, and a downwardly facing convex surface rigid with said column and floating on said concave surface.",
    "3. A support system according to claim 2 wherein said concave and convex surfaces are the bearing and journal portioNs of a bearing assembly; said column is rigid with elongated and is secured to said convex surface, and a fluid under pressure between said surfaces floats said convex surface on said concave surface.",
    "4. A support system according to claim 3 wherein said concave and convex surfaces are each spherical.",
    "5. A support system according to claim 3 wherein said concave surface is the concave surface of a bearing of cylindrical curvature, and said convex surface is the convex surface of a journal of the cylindrical curvature.",
    "6. A support system according to claim 5 wherein thrust bearing means limit axial movement of said journal relative to said bearing.",
    "7. A support system according to claim 6 wherein said thrust bearing means includes a shoe on said journal facing an end surface of said bearing, and means to direct fluid under pressure through said end surface.",
    "8. A vibration eliminating support arrangement to isolate an instrument from the effects of external vibration comprising, in combination a support structure; an instrument support; low friction bearing means mounting the instrument support on the support structure for free swinging movement about a preselected center; and an instrument, the utility of which can be impaired by vibrations transmitted to the instrument support, the instrument being carried by the instrument support; the support and instrument having respective centers of mass the resultant of which is below the preselected center of swinging movement of the instrument support so that vibrations of the support structure caused by external forces are converted to slow pendulum type swinging motion of the instrument support and instrument.",
    "9. A support arrangement according to claim 8 wherein the low friction bearing means include a bearing connected to one of said support structure and instrument support, a journal connected to the other of said support structure and instrument support, and means to create a fluid film between the bearing and the journal to maintain the bearing and journal in essentially friction free relation to each other.",
    "10. A support arrangement according to claim 9 wherein the bearing is secured to the support structure; and the journal is secured to the instrument support.",
    "11. A support arrangement according to claim 9 wherein the means to create a fluid film between the bearing and the journal includes a source of pressure fluid, and passage means connected to the pressure fluid source and opening through a bearing surface of the bearing.",
    "12. A support arrangement according to claim 9 wherein the arrangement further includes thrust bearing means to limit relative axial movement of the journal and bearing; the thrust bearing means comprising an end face of the bearing having a pressure fluid passage opening therethrough, and a thrust shoe rigid with the journal and extending across the passage in opposed relation to the end face of the bearing."
  ],
  "cpc": [
    "H01J 37/02"
  ],
  "assignees": [
    "COLEMAN J",
    "MC GINNIS J",
    "FAIRBANKS J",
    "HOFFMAN A",
    "NEWTON K",
    "SCHULER J",
    "MC LAUGHLIN P",
    "JOHNSON G"
  ],
  "filing_date": "1970-10-02",
  "publication_date": "1974-06-04",
  "grant_date": "1974-06-04",
  "priority_date": "1970-10-02",
  "application_number": "US-7771870-A",
  "family_id": "22139661",
  "citations": [
    "US2915902A",
    "US3016273A",
    "US3021956A",
    "US3026150A",
    "US3176507A",
    "US3248542A",
    "US3297284A",
    "US901329A"
  ]
}