Patent ID: 7353563
Filing Date: 2008-04-08
Classification: A47L

Abstract:
1. A vacuum cleaner height adjustment mechanism, comprising: a cleaning head having a pair of laterally spaced front wheels and a pair of laterally spaced rear wheels mounted for rotation on the cleaning head for supporting the cleaning head on a floor during vacuum cleaning operations; the front wheels being mounted to a common axle mounted in the cleaning head for pivotal movement around a fixed axis, the wheels being mounted to the axle offset from the pivotal axis of the axle; an arm extending from the axle; a shaft mounted substantially horizontally in the cleaning head for rotation about a central axis disposed in a vertical plane perpendicular to a vertical plane containing the axis of the axle, one end of the shaft having spiral threads thereon and an opposite end having an adjustment knob fixed thereto for manually rotating the shaft; a guide member having internal threads matching and engaged with the spiral threads on the shaft for movement along the shaft, the guide member being coupled to the arm extending from the axle so as to pivot the axle when the shaft is rotated by rotating the knob, whereby the front wheels are raised or lowered relative to the cleaning head; an indexing block fixedly secured to the cleaning head and having a cylindrical opening therethrough, the shaft passing through the cylindrical opening in the indexing block; an indexing member having a central opening through which the shaft extends, the indexing member being fixed to the shaft for rotation therewith; and a spring urging the indexing member into engagement with the indexing block; the indexing block and the indexing member having at least one cooperating detent and indent disposed radially around the axis of the shaft for holding the shaft in a fixed position after manual rotation.