CLEANING HEAD

Abstract: An elongate suction cleaning head comprising a housing (10) which defines a suction chamber having therein an inner compartment (21) provided with a liquid delivery inlet (13). The inner compartment (21) is defined in part by side walls (14) which extend substantially to the plane of an open mouth defined by the suction chamber, and the inner compartment is provided with a closure member (20) at a position spaced slightly inwardly from the lower ends of the side walls (14). Openings (24) adjacent to the opposed ends of the closure member (20) enable liquid to be delivered from the inner compartment (21) at positions adjacent to opposite ends of the outer housing (10). The underside of the closure member (20) is preferably formed with fine grooves to provide a capillary action which assists in drawing the liquid towards the centre of the cleaning head.

Description: Title: "Cleaning Head" Description of the Invention This invention relates to a cleaning head for use with an apparatus for cleaning walls, floors, carpets, curtains, upholstery and the like, and more particularly concerns a cleaning head for use in the process of water extraction cleaning, in which a carpet or the like is thoroughly wetted by a solution containing a suitable cleansing agent, such as non-foaming detergent, and the carpet or the like is then dried by the uptake of that solution by means of suction. Such a cleaning head is the subject of our British Patent No. 1601455 and the present invention concerns a development of the design disclosed therein. According to the present invention we provide an elongate suction cleaning head comprising a suction chamber having an open mouth for application to a surface to be cleaned and a centrally disposed suction outlet for connection to a source of suction, and an elongate inner compartment which extends substantial ly medial ly within the suction chamber, the inner compartment having a liquid inlet opening, side walls terminating substantial ly in the plane of the open mouth of the suction chamber and a closure member at a position adjacent to the ends of the side walls thereof whereby the inner compartment serves as a liquid delivery chamber, the closure member closing said chamber except for outlet openings adjacent to opposed ends of the inner compartment, the arrangement being such that when the cleaning head is applied to a surface to the cleaned, cleaning liquid flows from said chamber through said openings and is constrained between the ends of the side walls of said inner compartment and the closure member so as to be shielded from air flow arising from vacuous conditions within the suction chamber. Surprisingly, we have found that by confining the delivery of the cleaning liquid to localised points adjacent to the opposed ends of the cleaning head in this way it is possible to obtain uniform wetting of the surface to the cleaned over a greater width than with a cleaning head of the type described in our aforesaid patent, in which the liquid is delivered through a row of closely spaced fine apertures which extends across substαntiαfly the entire width of the head. Since the liquid is concentrated into two delivery zones, the overall quantity of liquid applied at these zones, even with the low flow rates for which such heads are intended, is such as to allow the liquid to flow inwardly under the closure member in the mouth of the inner compartment. These and other features of the present invention will now be described by way of example with reference to the accompanying drawings which show a preferred embodiment of the cleaning head in accordance with the invention. In the drawings:- FIGURE I shows the head in a sectional front elevation; FIGURE 2 shows a section on the line X-X of Figure I ; and FIGURE 3 shows an underneath plan view. The preferred form of cleaning head comprises an elongate housing 10 with a centrally disposed tubular outlet spigot 1 1 for attachment to a suction hose (not shown). An internal hollow boss 12 for the reception of a nozzle at the end of a pipe (not shown) through which a cleaning liquid is supplied is formed integrally within the spigot 1 1 and terminates in a liquid inlet aperture 13 which is disposed central ly within the housing 10 on the medial centre line thereof. On either side of the longitudinal centre line of the housing a pair of integral ly moulded internal walls 14 protrude downwardly from the top wall 15 of the housing. The walls 14 are spaced inwardly from the side walls 16 of the housing and extend paral lel to -the side walls 16 and upto the end walls 17 thereof so as to divide the housing into two spaced portions 10a, I0b_ of a suction chamber both of which are in communication with the outlet spigot 1 1. A pair of reinforcing struts 26 extend between the central points of the internal walls 14 and the side walls 16 of the housing. An integrally moulded strap 18 supports the lower end of the boss 12 and closes off the space between the internal walls 14 from the outlet spigot 1 1. Thus, the suction at the outlet spigot is applied to both portions lOa Ob of the suction chamber defined by the housing 10, but not to the space between the internal walls 1 . This space forms a compartment 21 which is substantially closed by means of a member in the form of a spreader plate 20 which is located slightly inwardly from the lower ends 14a of the walls 14, which edges are substantially co-planar with the open mouth of the housing 10. As best seen in Figure 2 the internal walls 14 are formed with rebates 22 adjacent to their free ends 14a to receive the spreader plate 20, and the latter is formed with a pair of upstanding ribs 25 which engage against the inner faces of the internal walls 14. However the spreader plate 20 does not extend fully up to the end walls 17 of the housing 10, but in the il lustrated embodiment stops short thereof and is located clear of both end walls by means of protrusions 23 formed at the junction between the internal walls 14 and the end walls 17. Thus, outlet openings 24 are provided at the opposed ends of the compartment 21. In use, a cleaning liquid is supplied through the hollow boss 12 and the inlet aperture 13 to the interior of the compartment 21 above the spreader plate 20. The cleaning solution may be supplied to the compartment 21 by any appropriate means. In particular, the cleaning head is designed for use with substantially non-pressurised liquid delivery systems. Thus, the liquid may be supplied gravitational ly, or by a syphon system, in either case optional ly assisted by a slight positive pressure generated for example by the application of exhaust air from the suction cleaner fan to a liquid reservoir in the manner disclosed in our British Patent No. 1601456. Alternatively a bleed hole (not shown) may be formed in the strap 18 so that suction within the spigot 1 1 establishes a reduced pressure within the compartment 21 to draw liquid from a reservoir in the manner described in our European Patent Specification No. 0316848. Although the rate of delivery of the cleaning liquid is relatively low, the quantity delivered at each of the outlet openings 24 is sufficient to flow inwardly within the space below the spreader plate 20 and bounded laterally by the lower ends of the internal walls 14. To assist the distribution of liquid, the underside of the plate 20 is preferably formed with fine grooves which provide a capil lary action tending to draw the liquid along the underside of the plate, which is sufficiently close to the lower ends 14a of the internal wal ls 14 to be contacted by the pile of a carpet on which the head is placed. Typically, the underside of the spreader plate 20 may be disposed approximately I mm above the end 14a of the internal wal ls 14. The arrangement of the lower ends 14a of the internal walls 14 in substantially the same plane as the mouth of the housing 10 ensures that the space beneath the spreader plate 20 is effectively sealed against the fabric being treated and there is virtually no possibility of the liquid passing through the openings 24 being drawn away by virtue of the air flow established within the head. Instead, the liquid is shielded by the lower ends of the internal walls 14 and applied directly to the fabric being cleaned in such a manner that it spreads inwardly from opposite ends of the plate 20 and effectively wets the fabric thoroughly over the full width of the cleaning head. Surprisingly, we have found that the use of the spreader plate 20 with outlet openings 24 adjacent the ends thereof makes is possible to increase the overall width of the cleaning head as compared with a prior arrangement in which the liquid is supplied through a row of closely spaced fine outlets extending substantially entirely along the length , of the head. In an alternative arrangement it would be possible for the plate 20 to extend fully upto the end walls 17 of the housing so as to eliminate the openings 24 as illustrated, and instead form equivalent openings at positions near the ends of the plate. In a further alternative arrangement, the inner compartment could be defined by a separable inner housing having side walls spaced from the side walls 16 and top waif spaced from the top wall 15 of the outer housing 10, with the boss 12 connected to said inner housing.

Claims: CLAI S:- I . An elongate suction cleaning head comprising a suction chamber having an open mouth for application to a surface to be cleaned and a centrally disposed suction outlet for connection to a source of suction, and an elongate inner compartment which extends substantially medially within the suction chamber, the inner compartment having a liquid inlet opening, side walls terminating substantially in the plane of the open mouth of the suction chamber and a closure member at a position adjacent to the ends of the side walls thereof whereby the inner compartment serves as a liquid delivery chamber, the closure member closing said chamber except for outlet openings ajdacent to opposed ends of the inner compartment, the arrangement being such that when the cleaning head is applied to a surface to be cleaned, cleaning liquid flows from said chamber through said openings and is constrained between the ends of the side walls of said inner compartment and the closure member so as to be shielded from air flow arising from vacuous conditions within the suction chamber. 2. A cleaning head according to Claim I wherein the closure member is spaced slightly inwardly from the ends of the side wal ls of the inner compartment. 3. A cleaning head according to Claim 2 wherein the closure member is located within rebates formed in the side walls of the inner compartment. 4. A cleaning head according to anyone of the preceding claims wherein said outlet openings are defined between opposed ends of the closure member and end wal Is of the suction chamber. 5. A cleaning head according to anyone of the preceding claims wherein the underside of the closure member is formed with fine grooves such as to provide a capilliary action. 6. A suction head according to anyone of the preceding claims wherein the side walls of the inner compartment extend upto a top wall of the suction chamber and across suction outlet, the interior of the inner compartment being isolated from the suction outlet. 7. A cleaning head according to anyone of Claims I to 5 wherein the inner compartment is formed as a separable inner housing. 8. A cleaning head according to anyone of the preceding claims wherein communication between the inner compartment and the suction chamber is provided by a bleed-hole in the upper region of the inner compartment so as to establish reduced pressure therein when suction is applied to the suction outlet of the suction chamber. 9. A suction cleaning head substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

Inventors: ATKINSON MICHAEL, ATKINSON, MICHAEL
Applicants: VAX APPLIANCES LTD, VAX APPLIANCES LIMITED
Application year: 1989
Main classification: A47L11
IPC codes: A47L11