Description of the Invention

This invention relates to a cleaning head for use with an apparatus for cleaning floors, wal ls, 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 a 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. 1 601455 and the present invention concerns a development of the design disclosed therein.

According to the present invention we provide an elongate cleaning head comprising a suction chamber having an open mouth and a central ly disposed outlet for connection to a source of suction, and an inner compartment extending substantial ly medially within the suction chamber and having side wal ls defining an open mouth substantial ly in the plane of the open mouth of the suction chamber, the inner compartment having associated therewith a cleaning liquid distributing chamber formed with a plurality of closely spaced f ine outlet passageways adapted to al low cleaning liquid to f low into the inner compartment at a position spaced from the mouth thereof, wherein the suction chamber is divided into two lateral ly spaced suction zones by means of a central baffle which diverges in a direction away from the open mouth of the suction chamber towards an upper zone of the suction chamber into which upper zone said outlet opens.

The divided suction chamber with the upwardly divergent baff le causes the air flow through the head from the open mouth to the outlet to be split into two streams which diverge away from the centre of the head in the respective suction zones and then converge towards the outlet in the upper zone of the head. This arrangement makes it possible to increase the transverse width of the head without reducing the efficiency of the liquid pick-up operation and without increasing the overal l air flow requirement. Thus in practice, the use of a cleaning head in accordance with the present invention typical ly makes it possible to utilise a cleaning head having a width

of approximately 20cm (8 inches) without increasing the air flow requirement over that which would otherwise be required for a 12.5cm (5 inch) head whilst maintaining equivalent efficiency of operation.

In accordance with a further feature of the invention the inner compartment is formed or provided with a separating wall dividing it into an outer liquid delivery chamber adjacent to said open mouth of the inner compartment and an inner chamber which serves as said liquid distributing chamber, said outlet passageways being formed in said separating wall.

Preferably said liquid distribution chamber is so dimensioned to serve as a storage reservoir within the cleaning head, for the cleaning liquid, which reservoir has a height sufficient to create a substantially equal hydrostatic head pressure at each of the outlet passageways. Typically the height of the reservoir may be at least 10 mm.

Preferably said liquid distribution chamber has sufficient volume such that when substantially full a substantially equal flow rate of cleaning liquid from each of the outlet passageways can be achieved during application of the open mouth to a surface. Typically, the volume may be approximately lcc per linear centimetre of the head.

The open mouth of the inner compartment is preferably of elongate configuration and said inner compartment preferably extends across the suction chamber substantially parallel to the main axis thereof.

The open mouth of said inner compartment is preferably located substantially centrally within the open mouth of the suction chamber whereby air-flow into the suction chamber takes place on both sides of the open mouth of the inner compartment, and the upper side of the body is preferably spaced above the upper side of the inner compartment by such a distance as to allow substantially unrestricted air-flow towards the outlet from both sides of the inner compartment.

According to a further preferred feature of the invention said inner compartment may be formed as a separate unit which is removable from the suction chamber, although it may alternatively be formed integrally.

The present invention further resides in an improved suction cleaning head comprising a body defining a suction chamber having a boundary wall defining an open mouth and having an outlet adapted to be connected to an air extraction means, and an inner compartment extending across the suction chamber and having a substantially planar open mouth parallel or co-planar with the open mouth of the suction chamber, wherein said inner compartment

is formed or provided with α separating wal l dividing it into an outer liquid delivery chamber adjacent to said open mouth of the inner compartment and an internal liquid distribution chamber which extends across the suction chamber and which has an inlet adapted to be connected to a supply of cleaning liquid, and a plurality of flow passageways are provided which extend through said separating wal l between the liquid reception chamber and the liquid delivery chamber.

The invention further resides in a separable inner housing for a suction cleaning head and comprising an elongate body affording an elongate open mouth, the housing being formed or provided with a separating wal l dividing it into an outer liquid delivery chamber adjacent to said open mouth and an inner liquid distributing chamber having a liquid inlet, said separating wall being formed with a plural ity of fine outlet passageways at closely spaced intervals along the length thereof to al low liquid to f low from said liquid distributing chamber into said liquid delivery chamber at a position spaced from the open mouth.

These and other features of the present invention wil l now be described by way of example with reference to the specific embodiments il lustrated in the accompanying drawings wherein:-

FIGURE I shows a first embodiment of cleaning head in a part- sectional front elevation;

FIGURE 2 shows an underneath plan view thereof;

FIGURE 3 shows a vertical section on the line Il l-Ill of Figure I ;

FIGURE 4 shows a second embodiment of cleaning head in a part sectional front elevation;

FIGURE 5 shows a vertical section on the line V-V of Figure 4;

FIGURE 6 is a side view of an inner housing for cleaning head as shown in Figures 4 and 5;

FIGURE 7 is a cross-section on the line VI I— VI I of Figure 6;

FIGURE 8 is an underneath plan view of the inner housing shown in Figure 6;

FIGURE 9 is a side view of a T-section bar which fits into the inner housing shown in Figure 6; and

FIGURE 10 is an end view of the T-section bar.

The first embodiment of cleaning head in accordance with the invention as il lustrated in Figures I to 3 comprises an elongate outer housing 10 with a central ly disposed tubular outlet spigot 1 1 for attachment to the suction hose

(not shown). The outer housing 10 receives therein α structurally separate medial ly extending inner housing 20 having side walls 22 which are spaced from the side walls 12 of the outer housing and an upper wall 23 which is spaced from the upper wall 13 of the outer housing. The side walls 22 of the inner housing 20 each carry a shallow V-formation rib 24 including wings 24a, 241) which bridge the space between the side walls 22 of the inner housing and the side walls 12 of the outer housing.

As can be seen from Figure I , the wings 24a_, 24b diverge upwardly away from the open mouth 15 of the outer housing and outwardly from the centre. The ribs 24 serve as baffles whereby the suction chamber defined by the outer housing 10 is divided into two laterally spaced suction zones 16a, I6b in which air drawn in through the open mouth 15 is divided into two divergent streams as indicated by the arrows A and B. The ribs 24 terminate at positions approximately half way between the centre line and the end walls 14 of the outer housing, so that the air flows enter an upper zone 17 of the outer housing above the inner housing 20 and converge towards the outlet spigot 1 1 as indicated by arrows C.

The portion of the inner housing 20 adjacent to the open mouth 25 accommodates a T-section bar member 30 whereof the transverse web 32 is received innermost and is supported at the ends of the inner compartment 20 by engagement within recessed portions of the end walls thereof. The central leg 31 of the T-section bar member 30 extends downwardly from the web 32 and terminates in the plane of the open mouth 25 of the inner compartment 20.

The lateral edges of the transverse web 32 of the T-section bar member 30 are formed with a plurality of spaced calibrated grooves 33 which extend between each face thereof.

The transverse web 32 of the T-section bar member 30 forms a separating wall which divides the inner compartment 20 into an internal liquid distribution chamber 26 above the transverse web 32 and an outer liquid delivery chamber 29 below the transverse web 32, between which chambers communication is provided through the grooves 33. The chamber 26 within the inner housing above the bar 30 has a volume such that it servces as a reservoir for the reception of a cleaning solution which is supplied through a pipe (not shown) to an inlet spigot 21 which protrudes from the inner housing as shown in Figures I and 3, whereby when substantial ly ful l there is a substantially equal rate of delivery from each passageway 33 under equal hydrostatic pressure.

The calibrated grooves 33 are provided at spaced intervals along substantial ly the entire length of the edges of the web 32 to regulate the flow of liquid so as to cause it to be delivered uniformly and continuously at an appropriate rate. Typical ly, the apertures 33 have a width of about 0.5 mm and are spaced on 10mm centres. The cleaning solution may be supplied by any appropriate means to the chamber 26, which may typically have a height of at least I cm and a volume of about I ce per centimetre of its length.

In particular, the head illustrated in Figures I to 3 is designed for use with substantial ly non-pressurised liquid delivery systems. Thus, the liquid may be supplied gravitationally, 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.

The space within the inner housing below the transverse flange 32 of the bar 30 defines the liquid delivery chamber 29 which extends medially of the outer housing 10. The arrangement of the end faces of the side wal ls 22 in the same plane as the mouth of the outer housing 10 ensures that such inner compartment is substantial ly sealed against the fabric being treated and that there is virtual ly no possibility of the liquid passing through the grooves 33 being drawn away directly by virtue of the air flow established within the head. Instead, the liquid is shielded by the side wal ls 22 and is constrained by the side wal ls to f low onto the fabric being cleaned. In this way, a thorough wetting of the fabric is ensured without spraying. This in turn makes it possible for the appliance to operate with only a low pressure gradient acting on the - liquid, and without the need for any pump for the delivery of cleaning liquid to the head under substantial pressure.

The divided air flow resulting from the ribs 24 ensures that substantially uniform suction is applied over the entire length of the head, which can thus be made sigificantly greater than in the absence of such ribs without requiring an increase in the overal l air f low and without employing a correspondingly more powerful motor to drive the fan of the suction cleaner.

As can be seen most clearly from Figure 3 the space above and around the inner housing 20 is such as to provide substantial ly unimpeded air-f low through the suction chamber on both sides of the inner housing, and over the top thereof into the upper zone 17 of the outer housing 10 and thence to the outlet I I .

The second embodiment shown in Figures 4 to 10 is of generally similar form to that of the first embodiment described above and the same reference numerals are used to denote corresponding parts, the following description being largely confined to features of difference.

The outer housing I0A of the second embodiment is somewhat deeper than theat of the first embodiment and the inner housing 20A is also deeper than that of the first embodiment with a flat upper wall 23A.

The modified inner housing 20A as illustrated in Figures 6 to 10 is generally similar in construction to the inner housing 20 previously described, except in the following respects.

The wings 24a, 24b of the shallow V-shape ribs 24 do not extend directly to the lower edge of the inner housing, but an additional, vertical wing 24c extends downwardly from the point at which the wings 24a, 24b meet and terminates at the lower edge of the housing 20A.

Internal ribs 22a_ are formed on the side walls of the housing 20A and terminate as shown at positions spaced inwardly from the open mouth of the housing. The ribs 22 serve to locate the T-section bar 30 within the housing 20A.

Whilst the calibrated air-flow passageway in the illustrated embodi¬ ments comprises a pair of small apertures 28 which extend through the upper wall of the inner compartment and open into the upper region of the suction chamber I I , other arrangements are possible. For example there may be a single opening in the upper region of the side wall 22 of the inner compartment 20 in register with the opening afforded by the outlet 14, or a tube may extend from the inner compartment into and along the length of the outlet 14.

If desired, the inner housing may be formed as a set of modules which can be interengaged in end-to-end relationship and to be receivable within suction heads of a variety of dimensions as required. By the use of such separate modules, a conventional suction head may be adapted for use for wet cleaning of floor surfaces.

Moreover, whilst in the illustrated embodiments a single V-formation rib 24 is formed on each side of the inner housing in a central region thereof, it may be appropriate to provide additional V-formation ribs at positions offset from the central region towards the ends of the housing, particularly for heads of increased width.