GB2031270A

GB2031270A - Surface cleaning

Info

Publication number: GB2031270A
Application number: GB7920583A
Authority: GB
Original assignee: BIGGLESWADE DEVELOPMENTS Ltd
Current assignee: BIGGLESWADE DEVELOPMENTS Ltd
Priority date: 1978-03-16
Filing date: 1979-06-13
Publication date: 1980-04-23

Abstract

A method of cleaning floors and walls comprises supplying a cleaning liquid to the surface being cleaned using the exhaust air from a motor-fan unit of a vacuum cleaner and removing the dirty liquid from the surface by suction. The apparatus for carrying out the method may comprise a housing 1 having two chambers 2, 3 for dirty and clean liquid respectively, a motor-fan unit 9, 10, a suction nozzle 33 connected to chamber 2 by means of tube 31 and wand 32, and a liquid distributor 35 connected to chamber 3 by tube 34, pipe 22, and tube 25. In use, when the motor is switched on, exhaust air flows via conduits 14, 16, 7 into chamber 3 via orifice 20 and into pipe 22, where it flows through orifice 24. Cleaning liquid is induced into the air stream as it exits through orifice 24 via nozzle 26 of tube 25, and the mixture is supplied to distributor 35, The suction nozzle may be provided with strips of water-absorbent, cellular material or squeegees to assist in the cleaning and drying of the surfaces. <IMAGE>

Description

SPECIFICATION Surface cleaning This invention relates to methods and apparatus for cleaning surfaces, particularly vertical surfaces.

In accordance with one aspect of the invention there is provided a method of cleaning a surface comprising transporting a cleaning substance to the surface by means of exhaust air from air pressure differential creating means and removing the cleaning substance from the surface by means of intake air to said air pressure differential creating means.

Preferably said method includes causing a -mixture of said cleaning substance and some at least of said exhaust air to be directed towards said surface-from a point adjacent to said surface.

Preferably also the exhaust air is injected into the cleaning substance.

In accordance with another aspect of the invention, apparatus for cleaning a surface comprises an air pressure differential creating means, distribution means for distributing a cleaning substance onto the surface and operable by exhaust air from said pressure differential creating means, and means for connecting a cleaning element applicable to said surface to the intake side of said pressure differential creating means so that said cleaning substance may be transferred from said surface entrained in said intake air.

Preferably, the distribution means includes means for injecting some at least of said exhaust air into the cleaning substance being transported to said surface.

In accordance with both the above defined method and apparatus aspects of this invention it is preferred that the cleaning substance be liquid and that part a.t least of the exhaust air from the pressure differential creating means should travel at a high velocity and be used to entrain droplets of the liquid and transport them to the surface to be cleaned. Preferably also, the liquid is presented to the high speed air at a nozzle at one end of a supply tube whose other end is immersed in a body of the liquid and it is further preferable that this body of liquid be subject to the positive pressure of the exhaust air.

Preferably also, the intake air used to transport the cleaning substance away from the cleaning surface is derived from the entrance to a cleaning wand and it is possible to bypass the intake end of the wand by means readily accessible to an operator. Preferably also, the outlet end or exit point for the liquid being distributed onto a surface is located adjacent the intake end of the wand and, preferably also, means for controlling the flow of the cleaning substance are provided adjacent the operators control for the adjustment of the intake air.

In accordance with a further aspect of the invention there is provided a cleaning head comprising a housing defining a chamber and having fixed to an outside surface portion thereof water absorbing cellular material, such as a sponge, for contacting a surface to be cleaned and ducts communicating the chamber with the material so that on application of a negative pressure to the chamber negative pressure is also applied to the material to extract moisture therefrom.

In accordance with a still further aspect of the invention there is provided a cleaning head comprising a housing defining a chamber and an aperture opening into the chamber and sealing means surrounding the opening, at least part of said sealing means being a flexible strip depending from the housing and having one surface which is substantially flat and an opposite surface which is formed with grooves which extend away from the free edge of the flexible sealing means towards the housing.

These and other aspects of the present invention will be further explained in the following description of preferred embodiments of the present invention, which are also illustrated in the accompanying drawings in which: Fig. 1 is a part sectional schematic view of cleaning apparatus including a wand and a cleaning head and liquid distribution and storage means; Fig. 2 is a sectional schematic view of a cleaning head; and Fig. 3 is a schematic bottom plan view of another cleaning head.

In a preferred embodiment of apparatus for cleaning floors and walls in accordance with the present invention and illustrated in Figure 1, there is provided a housing 1 which defines two storage containers 2, 3 located one above the other and respectively for dirty and clean liquid. The housing is split transversely at a point between the two containers and means (not shown) are provided for holding the two parts of the housing together as a rigid assembly. The lower part of the housing containing the lower container has a bottom wall 4 and an upper wall 5 which defines with the bottom wall 6 of the upper part of the housing a closed chamber 7 when the two parts of the housing are sealed together. A vacuum head 8 is secured to the top of the open topped upper container 2 to define a sealed upper container 2.

The vacuum head 8 includes a motor 9 which drives a fan 1.0 which constitutes the air pressure differential creating means of this embodiment of the invention. A fan intake is defined by an opening 11 in the vacuum head which connects the fan to the interior of the upper container 2.

There are two outlets from the exhaust side of the fan. A first outlet 12 is closed by a spring loaded flap 13, movement of which away from the opening causes the closing of the contacts of an electrical supply to the fan motor 9. The second outlet 14 passes to a branched conduit which has a valve 15 at the branch which is able to direct exhaust air either to atmosphere or along a further conduit 16 which terminates in the closed chamber 7 between the two containers 2, 3. The valve 1 5 is manually operable to determine the direction of flow of the exhaust air in the branched conduit.

The two openings are provided in the upper wall of the bottom container. A first opening 20 leads from the closed chamber 7 between the two containers 2, 3 into the lower container so that exhaust air from the fan directed into this chamber 7 is applied to the upper surface of any liquid in the lower container 3. The second opening 21 in the chamber 7 communicates the closed chamber to a pipe 22 which extends across the top of the lower container and is connected to an outlet opening 23 in a wall of the lower container housing. Thus, exhaust air can be directed to the outlet opening from the closed chamber and the fan. At a certain point in the length of this conduit there is provided an orifice 24 so that air emerging from the orifice has a high velocity.A supply tube 25 for liquid from the lower container 3 has its free end located near the bottom of the lower container and its upper end protruding into the pipe 22 and terminating in a nozzle 26 which is aligned with the orifice 24 and downstream of the orifice. Air passing through the orifice is injected into the liquid emerging from the end of pipe 22 or entrains liquid emerging from the nozzle or otherwise is mixed into the liquid and the mixture is transported out of the outlet opening 23 in the lower container. The exhaust air pressure applied to the body of liquid via the opening 20 ensures the flow of liquid to the nozzle in spite of the increasing head of liquid to be moved as the lower container empties.

At the top of the upper container 2 there is provided an inlet connection 30 for intake air to the fan and associated with this intake opening there are provided bleed holes (not shown) for air to be allowed to the fan to ensure that the spring loaded flap remains open and the fan remains operative even though the main intake may be temporarily obstructed.

A first flexible tube 31 is connected by one end to the inlet connection 30 in the upper container and has its other end connected to one end of a rigid wand 32. A cleaning head 33 is affixed to the other end of the wand 32. A second flexible tube 34 has one end connected to the outlet opening 23 in the lower container and extends from this outlet opening into the interior of the first flexible tube 31 at a point close to the inlet connection into the upper container and then passes along this tube to emerge therefrom at a point close to the wand and it then passes down the outside of the wand and terminates at a point close to the cleaning head. A rigid distribution tube 35 having a plurality of spray holes is connected to the end of this second tube 34 and extends transversely of the cleaning head 33 and just behind it.

An air intake control for the wand is located at the end thereof close to the first flexible tube. The control consists of a sleeve 40 which is axially movable over the tubular wand to open and close a port therein. When the port is open the air intake through the cleaning head is bypassed. Adjacent this sleeve there is also provided a lever 41 which operates a control valve for the flow of air and liquid passing to the distribution tube 35 along the second flexible tube 34.

In operation of the machine described above in accordance with a preferred method of the present invention, the motor 9 is switched on by a main control and this control is released when the motor is operating sufficiently for the air flow from the fan 1 0 to move the spring loaded flap 13 to close the supply contacts incorporated therewith.

The valve 1 5 in the branched exhaust outlet is operated to direct flow of exhaust air into the closed chamber 7 between the upper and lower containers 2, 3 the lower of which is full of clean cleaning liquid and the upper of which is empty.

The inlet connection 30 to the upper container and the outlet connection 23 from the lower container are connected to their respective tubes 31, 34 and to the wand 32 which is equipped with a cleaning head 33. The air exhausted from the fan pressurizes the body of fluid in the lower container 3 and also exhausts across the orifice 24 and nozzle 26 into the distribution tube 35, when the valve in the distribution pipe is open. Air passing along the distribution pipe 22 is mixed into the liquid which emerges from the nozzle 26 and the mixture is carried along by its own energy content in the tube 34. The mixture exhausts through the distribution tube 35 and droplets of the liquid are distributed on the surface to be cleaned which may be a floor or may be a wall.It has been found that it is possible by suitable dimensioning of the orifice and the other elements of the apparatus to raise the cleaning substance to a height of 6 metres.

During the distribution process the sleeve 40 on the wand 32 may be located in its position in which the port in the wand is not closed so that the cleaning head 33 is bypassed and a full intake to the fan is by way of this opening and the upper container.

When sufficient liquid has been distributed on the surface to be cleaned the valve in the distribution pipe is closed by the lever 41 and the cleaning head 33 is moved over the surface to ensure even distribution of the cleaning liquid and to provide a scrubbing action along the surface.

When the operator is satisfied that sufficient work has been undertaken, the sleeve 40 on the wand is moved to close the port therein so that negative pressure is applied to the cleaning head. As a result, the dirty cleaning substance is drawn into the cleaning head by virtue of the flow of air and is transported to the upper container 2. The air velocity in the container is substantially less than that in the intake pipe 31 and therefore material entrained in the intake air is deposited in the upper container and collects in the bottom thereof. The volume of intake air is arranged to be sufficient to maintain a flow of air both into the outlet opening controlled by the spring loaded flap 13 and into the branched outlet leading into the closed chamber 7 between the upper and lower containers.In the event of a temporary blockage of the intake openings in the wand, sufficient air can be drawn in through the bleed holes provided in the upper container to keep valve 13 open.

It is also possible to provide in the upper container a safety valve which is float operated to close the intake 11 to the fan in the vacuum head when the lever of liquid in the upper container reaches a predetermined level so that the flap 13 closes to switch off the motor.

The apparatus and method described above provide that the flow of liquid or other cleaning substance to the area to be cleaned can be controlled very precisely and limited to the amount strictly required for ensuring that the surface is clean. It has been found that the supply of liquid can be so efficient that a 15 litre initial supply of the cleaning substance can last for approximately four hours in substantially continuous use of the machine.

The control of flow is dependent, of course, on the various characteristics of the air flow through, and the dimensions of, the orifice as well as those of the nozzle and the length of pipe and other factors which will be apparent to a man skilled in the art. In a preferred operational embodiment of the invention an electrically operated suction unit 9, 10 having a nominal rating of 750 watts (1 hp) was used. The outlet opening 1 2 has a diameter of 19 mm (3/4 inch) which was substantially fully open in use of the apparatus. The distribution tube 34 had a bore diameter of 8 mm (5/16 inch) and the diameter of orifice 24 was 1.8 mm (72/1000 inch). The length of tube 34 was sufficient to provide at least a metre lying on the ground when the cleaning head was at a height of about 9 metres and the apparatus operational.

It will also be apparent that modifications can be made to the apparatus specifically described above without departing from the scope of the various aspects of the invention which will have become clear by now. In particular, it is noted that the arrangement of the air supply and intake pipes can readily be altered.

As discussed above, the invention also provides various forms of cleaning head which are also intended to improve the removal of liquids from the surface to be cleaned so that these surfaces may be utilised as soon as possible after cleaning.

One embodiment of cleaning head in accordance with the invention comprises a generally rectangular plan and cross-section housing 50 (Figure 2) which has an upper face to which is connected a boss 51 for connecting to a wand. The bore in the boss extends into a chamber 52 defined by the housing. The side of the housing opposite the boss is a plate which has three parallel rows of holes therein. The first row 53 is located centrally of the plate and extends longitudinally thereof and the other two rows 54, 55 extend one on either side of the central row of holes close to the edges of the plate. Strips 56, 57 of water absorbing cellular material such as, sponge, are secured to the outer surface of the plate respectively one over each of the outer rows of holes. The middle row of holes therefore opens into the space defined between the plate and two strips of sponge.The free surfaces of the sponge are intended to rub over the surface to be cleaned.

When negative pressure is applied to the boss air is sucked in through the three rows of holes. The air sucked through the outer rows of holes 54, 55 serves to dry out the sponges and to improve the efficiency and speed with which the surfaces are cleaned and dried.

In another preferred embodiment of the invention a cleaning head 60 (Figure 3) comprises a housing as defined generally with respect to the other embodiment of cleaning head described above and illustrated in Figure 2. However the lower face of this cleaning head is provided with a single longitudinal and centrally located opening 61. Depending from the longitudinal edges of the lower plate are two squeegees 62, 63 (i.e. strips of flexible material). The inner faces of the squeegees 62, 63 are substantially smooth or plane. The outer surfaces of the two squeegees which face away from each other are formed with grooves 64 which extend upwardly from the free edges of the squeegees. The short transverse ends of the end plate are also provided with depending sealing means 65 in the form of flexible strips or pieces of sponge or other suitable material.Support wheels 66 are located one at each end of the housing and are supported on axles which are eccentrically rotatable in the housing to alter the height of the housing in a manner known to those in the art. In use of this preferred embodiment of the invention, the cleaning head 60 is moved backwards and forwards over the surface to be cleaned so that both squeegees 62, 63 contact the surface but one will contact the surface with its corrugated or grooved surface and the other squeegee will contact the surface to be cleaned with its smooth surface depending on the direction in which the cleaning head is moved. The grooves in the surface ensure that there is a substantial air intake as well as a high air intake velocity into the cleaning head when a negative pressure is applied in the chamber defined by the housing and improves the efficiency and speed of entrainment of cleaning substance from the surface to be cleaned.

Claims

1. A method of cleaning a surface comprising transporting a cleaning substance to the surface by means of exhaust air from air pressure differential creating means and removing the cleaning substance from the surface by means of intake air to said air pressure differential creating means.

2. A method according to claim 1 including causing a mixture of said cleaning substance and some at least of said exhaust air to be directed towards said surface from a point adjacent to said surface.

3. A method according to claim 1 or claim 2 including injecting some at least of said exhaust air into the cleaning substance.

4. A method according to any preceding claim including applying said exhaust air to a surface of a body of said cleaning substance.

5. A method according to any preceding claim wherein said exhaust air is pressurised with respect to the ambient atmosphere.

6. A method according to any preceding claim wherein the cleaning substance is a liquid.

7. Apparatus for cleaning a surface comprising an air pressure differential creating means, distribution means for distributing a cleaning substance onto the surface and operable by exhaust air from said pressure differential creating means, and means for connecting a cleaning element applicable to said surface to the air intake side of said pressure differential creating means so that said cleaning substance may be transferred from said surface entrained in the intake air.

8. Apparatus according to claim 7 wherein said distribution means is for causing part at least of the exhaust air from the pressure differential creating means to travel with the cleaning substance to a point adjacent to the surface to be cleaned.

9. Apparatus according to claim 8 wherein said distribution means includes means for injecting some at least of said exhaust air into the cleaning substance being transported to said surface.

10. Apparatus according to claim 9 wherein said cleaning substance is a liquid.

11. Apparatus according to claim 10 wherein exhaust air is injected into the liquid adjacent one end of a supply tube whose other end is immersed in a body of the liquid.

12. Apparatus according to claim 11 wherein said one end is a nozzle.

13. Apparatus according to any one of claims 10 to 12 wherein said injecting means is an orifice.

14. Apparatus according to any one of claims 11 to 13 wherein said body of liquid is arranged to be subjected to the positive pressure of said exhaust air.

1 5. Apparatus according to any one of claims 7 to 14 further comprising a cleaning wand and the intake air used to transport the cleaning substance away from the cleaning surface is derived from the entrance to the wand.

16. Apparatus according to claim 15 including means for bypassing the intake end of the wand, such means being readily accessible to an operator.

17. Apparatus according to claim 1 5 or claim 16 wherein an exit point for the substance to be distributed onto a surface is located adjacent the intake end of the wand.

18. Apparatus according to claim 17 further comprising means for controlling the flow of the cleaning substance, such means being provided adjacent an operators control for the adjustment of the intake air.

19. Apparatus according to any one of claims 7 to 18 wherein said distribution means includes a distribution tube for conveying said substance to a surface to be cleaned and having a bore of substantially 8 mm (5/16 inch) diameter and an orifice opening from the exhaust side of said air pressure differential creating means into said bore of substantially 1.8 mm (72/1000 inch) diameter.

20. Apparatus according to claim 19 wherein said air pressure differential creating means is or is equivalent to an electrically driven suction motor having a nominal rating of 750 watts (1 hp) whose exhaust to atmosphere is delimited by an opening of substantially 1 9 mm (3/4 inch) in order to pressurise said exhaust air.

21. A cleaning head comprising a housing defining a chamber and having fixed to an outside surface portion thereof water absorbing cellular material, such as a sponge, for contacting a surface to be cleaned and ducts communicating the chamber with the material so that on application of a negative pressure to the chamber negative pressure is also applied to the material to extract moisture therefrom.

22. A cleaning head according to claim 21 wherein said surface portion is rectangular and two strips of said material are fixed to said surface portion adjacent the longer edges thereof.

23. A cleaning head comprising a housing defining a chamber and an aperture opening into the chamber and sealing means surrounding the opening, at least part of said sealing means being flexible strip depending from the housing and having one surface which is substantially flat and an opposite surface which is formed with grooves which extend away from the free edge of the flexible sealing means towards the housing.

24. A cleaning head according to claim 23 wherein two said flexible strips are provided which extend parallel to each other on either side of said opening, the flat sides thereof either facing towards each other or facing away from each other.

25. A cleaning head according to any one of claims 21 to 24 further comprising means for connecting said housing to a cleaning wand and providing an air outlet from said chamber.

26. A method of cleaning a surface substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

27. Apparatus for cleaning a surface substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

28. A cleaning head substantially as hereinbefore described and illustrated in Figure 2 or Figure 3 of the accompanying drawings.