Indicators Patents (Class 15/DIG11)
  • Patent number: 4294595
    Abstract: An automatic shutoff arrangement for a vacuum cleaner of the "clean air" type in which the vacuum fan is downstream of the dirty air passageway and vacuum filter. The automatic shutoff arrangement includes an apparatus for sensing a selected characteristic of the air flow at a first point adjacent the entrance to the dirty air passageway and at a second point along the clean air passageway between the vacuum filter and fan and operates in response to a relative change in the selected characteristic between such points to interrupt power to the vacuum motor and/or indicate to the operator that the dirty air passageway is obstructed or vacuum filter is full.
    Type: Grant
    Filed: July 18, 1980
    Date of Patent: October 13, 1981
    Assignee: Electrolux Corporation
    Inventor: Leonard E. Bowerman