GB524437A - Improvements in or relating to agitators for suction cleaners - Google Patents

Abstract

524,437. Vacuum cleaners. HOOVER, Ltd. (Hoover Co.). Jan. 27, 1939, No. 4635/40. Divided out of 524,317, under which a Specification was laid open to inspection under Sect. 91 of the Acts, July 29, 1939. [Class 8 (i)] The brush 5, Fig. 1, of the rotary agitator of a vacuum cleaner is advanced as the bristles wear away in use, under the control of a feeler 62. When the brush is so worn that the feeler contacts with the carpet, it is rotated, releasing a tooth on the brush stock from the roller 68, and allowing the brush to advance half a tooth pitch until held by the pallet 69 ; a spring 70 then pulls the feeler back to its former position , releasing the pallet 69 from its tooth and allowing a further half tooth pitch advance. In another form, the feeler moves a ratchet to shift a plate having a stepped slot, the steps holding a pin on the brush in consecutive positions ; alternatively, the ratchet actuates the head of a screw engaging the brush stock. In another form the feeler engages a ratchet wheel carrying a cam which acts directly or indirectly on the brush; the cam may be constituted by a curved rack on the brush body. Fig. 4 shows ball wedges replacing ratchets ; the balls 86 prevent the brush moving inwards pressure on the feeler 62 allows the balls 88 to move freely backwards, and the brush is again carried forward with the feeler under centrifugal force assisted by a spring ; in a modification, the ball wedges 86 are replaced by a spring pushing the brush forward. Fig. 8 shows a feeler 62 mounted on a counterweighted bellcrank lever carrying a pawl 107 acting on a combined ratchet and cam 105, 106 co-operating with a pin 108 on the brush. Normally the feeler rests against the end of the brush and is withdrawn into the agitator body as the speed of rotation increases. When the brush is worn the feeler passes over the brush end permitting the pawl to advance a tooth, with consequent advance of the brush.