GB1395301A - Vacuum cleaner - Google Patents

Abstract

1395301 Vacuum cleaner PHILIPS GLOEILAMPENFABRIEKEN NV 17 July 1973 [20 July 1972] 33911/73 Heading A4F [Also in Divisions B 1 and G 1] A vacuum cleaner is provided, in a tube portion 1 situated between a suction nozzle and a dust filter, with an element 2 which may regulate the pressure at the nozzle since an opening 4 in the tube 1 is closable by the element 2, and also indicate the extent of clogging of the dust filter by functioning as a pressure sensitive device. In one embodiment, Fig. 3, an aperture 9 in the element 2 is in communication with the inside of the tube 1 whilst a second aperture 16 communicates with the ambient atmosphere. Since the apertures 9, 16 are separated by a flexible diaphragm 10 connected to a slide 12 which is provided with indicating means, e.g. red marks 13, any pressure difference in the tube 1 due to clogging of the filter causes the slide 12 to move. A window is provided with, for example white marks 15, so that movement of the slide 12 relative to the window serves as an indication of clogging. In a further embodiment, Fig. 5 (not shown) a scale is attached to a piston one face of which is in communication with the tube interior whilst the opposite face is in communication with the ambient atmosphere. In a third embodiment, Figs. 6 and 7 (not shown) a spring-biased piston moves over an inner cylinder, the inside of the piston being open to the tube pressure whilst the outer surface of the piston is open to the atmosphere.