The present invention relates to a cleaning system for cleaning an escalator or moving walkway, as well as to a cleaning pad and a cleaning brush and a vacuum unit and a cleaning head for use in such system.

Public moving walkways or escalators are among the most expensive, most trafficked, most visible and most dangerous of all flooring areas on earth.

While most flooring, including those that lead up to and away from escalators, are typically cleaned daily, the far more expensive, more visible, more trafficked and more dangerous escalators are relegated to infrequent cleaning. This is primarily due to the expense and complexities associated with escalator cleaning machines and services available and most commonly used today. Escalators are typically provided with multiple interconnected escalator steps, each having a number of parallel ridges and grooves. These ridges and grooves provide for a rather rough surface, preventing people from slipping on the step surfaces. On the other hand dirt, mud, soil and debris also tend to collect in these grooves, while these grooves are difficult to access.

Cleaning systems and cleaning pads are for instance known from

US2015/0259178. These systems however rely on a simple cleaning system with a handle, a head portion and a cleaning pad made out of two materials; an absorbent material for absorbing and retaining cleaning fluid, and a semi-rigid material, to provide rigidity to the cleaning pad to be able to align the ridges and the grooves of the pad and the escalator.

When such escalators are particularly dirty, cleaning the escalators is cumbersome work. Although cleaning systems for escalators are known, these are typically time consuming and expensive due to the machinery and complexity of the training required for such restorative cleaning. Additionally, a day or two after the restorative cleaning has been accomplished, the escalator will already have begun to accumulate dirt, dust, debris and an oil residue from the mechanics beneath.

It is therefore an object of the present invention to provide an improved escalator cleaning system. The present invention thereto provides a cleaning system for cleaning an escalator or moving walkway, comprising a cleaning pad comprising a contact surface for contacting the surfaces of the escalator or moving walkway to be cleaned; and a coupling surface, preferably opposite the contact surface, for coupling the cleaning pad to a cleaning head; a cleaning head for holding the cleaning pad comprising coupling means, for coupling the cleaning pad to the cleaning head, preferably arranged on a surface of the cleaning head directed towards the cleaning pad; an attachment element, for attaching the cleaning head to a machine or a handle or broom; a vacuum unit, arranged to be attached to a first side of the cleaning head, in particular to the front side of the cleaning head, comprising: an inlet opening, preferably aimed towards the surface of the escalator or moving walkway to be cleaned, and an outlet opening, preferably opposite the inlet opening, for attachment to a vacuum source and for removal of elements sucked up by the vacuum unit; and a cleaning brush, arranged to be attached to the first side of the cleaning head or to the vacuum unit, in particular to the front side of the vacuum unit, comprising: a plurality of brushes, extending towards the surfaces of the escalator or moving walkway to be cleaned and arranged to contact ridges and/or grooves of the escalator or moving walkway. The vacuum unit and the cleaning brush may be configured to be exchangeably attached to the cleaning system, and are preferably interchangeable with other similar vacuum units and cleaning brushes.

The vacuum unit and/or the cleaning brush may thus be configured to be bolted on, snapped on or otherwise be attached to the cleaning head. It is thus also

envisionable that the vacuum unit and/or the cleaning brush may be connected or attached to existing cleaning heads for escalator cleaning systems. The vacuum unit and the cleaning brush may also be embodied as a combined“single” unit, which in turn can be connected or attached to the cleaning head, for instance in an exchangeable, interchangeable, replaceable or detachable fashion. Again, this provides the option to provide the elements as an aftermarket solution, as well as allows replacement of faulty parts in an efficient manner, without the need to replace the complete cleaning unit.

In that embodiment the cleaning head and the vacuum unit and/or the cleaning brush may thus be separate elements, which can be combined at will. For instance, it would be possible to use the system with the elements combined for a first cleaning run of an escalator, for instance when the escalator is particularly dirty. This first run would make use of a dry cleaning pad in the cleaning head, and then remove most of the dirt on the escalator. The vacuum unit and the cleaning brush may then be removed and a wet cleaning pad may be used to remove any remaining dirt, stains or residue. By having the cleaning head and the vacuum unit and cleaning brush detachable, interchangeable or exchangeable, switching between these operating modes is relatively easy and quick. In front of the cleaning head a vacuum unit may thus be provided. Typically the cleaning pad and the cleaning head are elongated or rectangular shaped, and may for instance have a width between 500 and 750 mm, in particular about 600mm. Alternatively, wider versions with for instance a width between 750 and 1250, in particular between 800 and 1000mm may be envisioned. The long sides thereof typically extend along the width of the escalator surface to be cleaned. With“in front” of the cleaning head is meant that along one of the long sides of such cleaning head, and in line with the cleaning motion. Cleaning can be performed by moving the cleaning head over the walkway, wherein fresh parts of the walkway are thus first brushed before cleaned with the cleaning pad. In a preferred method however the cleaning system is kept stationary on the escalator, and the escalator moves underneath the cleaning system. With“in front” is then meant the part of the system that first encounters the dirty part of the walkway.

The coupling surface of the cleaning pad may be provided with coupling means as well, wherein the coupling means of the pad and the cleaning head are

complementary and mutually co-acting coupling means. The vacuum source may for instance be a vacuum cleaner. Preferably, the coupling surfaces of the cleaning pad are embodied as recesses, for instance T-shaped recesses, and the cleaning head is provided with protruding elements, for instance T-shaped protrusions, which protruding elements lock into the recesses of the cleaning pad. The cleaning pad may thus slide onto the protrusions of the cleaning head.

Alternatively, a cleaning system may be provided with a frame, the vacuum unit and the cleaning brush, for removing the bulk of the debris from the escalator or moving walkway. The frame in this alternative replaces the cleaning head and the cleaning pad.

The cleaning head and the vacuum unit may be provided with mutually interacting first connecting elements, for connecting the vacuum unit to the cleaning head and/or wherein the vacuum unit and the cleaning brush are provided with mutually interacting second connecting elements, for connecting the vacuum unit to the cleaning brush. Such connecting element may for instance be formed by nuts and bolts, and by possibly threaded openings in the cleaning head, cleaning brush and/or vacuum unit. The connecting elements may also be formed by snap elements or quick release elements, that could for instance be molded on the parts. Because both the cleaning brush and the vacuum unit are possibly removable connectable to the cleaning head through the connecting elements, it is possible to use the cleaning head without these attachments as well. The same basic elements used for usual maintenance can thus be turned into an upgraded element that can be used for a deep clean or restorative cleaning.

The cleaning brush may be provided with a connecting surface, for connecting the cleaning brush to the vacuum unit or the cleaning head, wherein the plurality of brushes may be attached to the connecting surface. The cleaning brush may for instance be provided with a plurality of tuft openings, in particular between 100 and 500, more in particular between 200 and 400 tuft openings, wherein the plurality of brushes are formed by a plurality of tufts extending from the tuft openings. Such cleaning brush may be attached to the cleaning head or the vacuum unit relatively easily through the connecting surface, whereas the brush configuration may be tuned to the desired needs as well. Typically, the connecting surface of the cleaning brush is relatively thin and elongated, with a width substantially

corresponding to the width of the cleaning head. The cleaning brushes extend from the connecting surface downwards, towards the surface to be cleaned, wherein these brushes preferably mesh with the generally ribbed surface of the escalator to be cleaned.

The brushes may be made from a material which comprises nylon. Nylon is widely available, and provides a relatively rigid and sturdy brush, which is able to sweep and release debris and dirt from between the ribs on the surface to be cleaned, without compromising its structural integrity.

Between the cleaning brush and the vacuum unit a rubber gasket may be provided and/or between the cleaning head and the vacuum unit a rubber gasket may be provided. By providing such gasket, a sealed connection between the elements may be achieved. This is particularly useful since the vacuum unit, when attached to a vacuum source, provide a low pressure zone around the cleaning head. This low pressure zone is used to suck up, or remove, dirt and debris (for instance worked free or agitated by the brushes) from the surface to be cleaned. Maintaining this zone increases the suction power and thus the cleaning power of the system. The cleaning pad itself may also contribute to this seal, preventing surrounding air from flowing towards the vacuum unit from the back of the cleaning head or from below the cleaning head. The gasket may have a width of about 500-750mm, in particular about 600mm.

The cleaning system may also comprise a spray unit, for instance mounted on a broom of the system, for spraying a cleaning liquid on the cleaning pad or onto to surfaces of the escalator or moving walkway to be cleaned. Mounting the spray unit on the broom of the system allows to locate the unit at a relative high height, allowing gravity to aid in the distribution of the cleaning liquid on the pad or surface. In the art, typically a saturation trough is used to saturate cleaning pads or sponges with cleaning liquid. In such systems, the pads or sponges are submerged in a trough filled with cleaning liquid, and removed after a certain period of time. The spray unit according to the invention eliminates the need of such troughs, and allows for a precise dosing of cleaning liquid on the cleaning pad and/or the surface to be cleaned. The cleaning head may for instance be provided with liquid dispensing or spraying heads, for spraying cleaning liquid. These heads are for instance provided on the front side of the cleaning head. It is also envisioned that the spray unit is used without the vacuum unit or the cleaning brush. In this embodiment, the system comprises the cleaning head, the cleaning pad and the spray unit.

The cleaning head may be provided with at least one blocking element, on a side of the cleaning head opposite the cleaning brush or vacuum unit, for distancing the cleaning head from combs of the escalator or moving walkway. The cleaning pads used for cleaning escalators or moving walkways are typically modular steps that interlock. In particular in escalators, these steps together form an endless loop, which at an incline forms moving steps. At the transitions between the upper and lower level between which the escalator extends, the steps of the escalators appear to merge on these levels. At those transitions, typically combs are present, which are protruding teeth that interlock with the grooves or ridges of the escalator. These combs may harm or damage the cleaning pad and/or the cleaning head. Therefore, the blocking elements may be provided, which in use may lie against the teeth of the combs, or distance the cleaning head and/or cleaning pad from these combs. These blocking elements may for instance be located slightly higher than at least the lowest portions of the cleaning pad so as not to drag or catch on the oncoming surfaces The contact surface of the cleaning pad may comprise ridges and/or grooves, for contacting ridges and/or grooves of the escalator or moving walkway. The ridges may interlock with the grooves of the escalator to be cleaned, wherein these ridges of the pad may thus extend into the grooves of the escalator steps, which allows for a better cleaning of the surface to be cleaned. The blocking element may then comprise ridges and/or grooves, which ridges and/or grooves either align with the ridges and/or grooves of the contact surface or are offset compared to the ridges and/or grooves of the contact surface. Purposefully providing these offset means that the ridges of the blocking element do not fit into the escalators tread grooves at all. To the contrary, the blocking ridges are then sitting just above the“tops” of the treads’ ridges. In this manner, the escalator combs top gaps are what is used to block the system from moving further. The grooves of the blocking elements may for instance have a width of 2-6mm, in particular about 4mm, and a depth of 10- 20mm, in particular about 15mm. The ridges of the blocking elements may have a width of about 3-7mm, in particular about 5mm and a height of about 15mm.

The cleaning pad may be made of an absorbent material, preferably an open cell flexible foamed material such as foamed polyurethane. The pad may for instance be both absorbent and rigid, wherein the pad has a rigidity over 70-ILD as measured according to ASTM-D3574, in particular the B1 method thereof with a 4 inch thick sample. In an embodiment, the cleaning pad had a rigidity over 150 pounds, which creates a relatively rigid cleaning pad which increases the scrubbing action of the pad compared to softer pads.

The rigidity of the pad may aid in the scrubbing action the ridges of the pad make in the grooves of the escalator. ASTM D3574 is a widely accepted test standard for testing soft polyurethane foam. There are several test procedures in this standard to help determine the compression, deflection, tear and tensile characteristics of flexible cellular materials (urethane foams and polyurethane foams). IFD

(Indentation force deflection) and ILD (indentation load deflection) are two of the more common compression tests in this standard, and are interchangeable. The test consists of measuring the force necessary to produce a designated indentation in the foam product. Within ASTM D3574, the indentation force deflection procedure is Method B1 which measures the force (in pounds) required to indent an eight inch diameter steel plate (called an indentor foot) into a foam sample to a stated percentage of the test sample's initial height which is commonly four inches. The test procedure, for example, compresses a four inch thick sample of foam until it reaches three inches thick, and the compressive load needed to displace it is measured. Common IFD values are generated at 25 and 65 percent of initial height. As an example, 35 lb IFD foams are associated with medium firm foam mattresses, and 45 lb IFD foams are associated with very firm mattresses.

The contact surface of the cleaning pad, or the surface of the cleaning pad used to contact the surface to be cleaned, may be provided with an abrasive surface, for instance formed by relatively stiff cells of the foam of the cleaning pad. The abrasive surface can be used to scrub off debris and dirt from the surface to be cleaned.

Preferably, the size of the cleaning pad corresponds to the size of the cleaning head. So, preferably, the width and length of the pad and the head substantially are the same. This provides the advantage that a relatively large surface area of cleaning pad can be used to clean the escalator, and an effective cleaning can be achieved. It is possible to make the complete pad out of a single absorbent material, and not needing a separate rigid protective element, since the pad according to the invention is not only absorbent, but also rigid. Since a relative large surface of the cleaning pad is cleaning, with absorbing and rigid action, cleaning action is much improved compared to pads which are either absorbent or rigid.

The cleaning pad may for instance be used in conjunction with a liquid cleaning solution. The pad with the ridges may then be used to dispense the liquid cleaning solution onto the escalator threads (or ridges and grooves), and once the dirt begins to moisten, emulsify and loosen, the cleaning pad contact surface material is what accomplishes the actual cleaning. In order to take up either fluid cleaning solution, moisture, or liquid mud, dirt or debris, the cleaning pad is made of absorbent material, such that the liquid cleaning solution may be held by the cleaning pad. The cleaning pad thus acts as a sort of sponge.

In an embodiment, the indentation hardness of the contact surface may be at least 250N at 25%, at least 350N at 40% and/or at least 800N at 65%, more in particular at least 300N at 25%, at least 400N at 40% and/or at least 900N at 65%, as measured according to ISO 2439:2008. Indentation hardness tests are used in mechanical engineering to determine the hardness of a material to deformation. Hardness measurements quantify the resistance of a material to plastic

deformation. A relative hard quality of the contact surface results in a pad able to withstand more forces which increases the cleaning and rubbing capacity of the contact surface of the pad, and the ridges thereof in particular. The hardness of the contact surface should, on the other hand, preferably be not so high that the ridges cannot deform anymore, to accommodate possible variations in geometry between different escalator steps, and the threads thereof in particular. The indentation hardness of flexible cellular materials is a measure of their load-bearing properties. This International Standard specifies four methods (A to D) for the determination of indentation hardness and one method (E) for determination of compressive deflection coefficient and hysteresis loss rate of flexible cellular materials. The 25- 40-65% is method B of the standard.

The contact surface of the cleaning pad may be made of a single absorbent material, which material is an open cell flexible foamed material, in particular a foamed polyurethane. By single absorbent material is meant that the complete contact surface of the cleaning pad is made of the same material. This eliminates the need of using multiple materials, for instance one material for absorbing a cleaning liquid and one material for rubbing or abrading the escalator step surface. Although using multiple materials may allow to select the material based on their specific purpose, bonding different materials together is costly and cumbersome, results in a slower production process and a more expensive cleaning pad in the end. Single absorbent material may also mean that the contact surface is made of one single pad, of a single material. There is then no separate material or additional pad on one of the sides of the cleaning pad, for instance on the side of the pad that rubs against the combs of an escalator during cleaning thereof. In an embodiment, the cleaning pad is not provided with a backing layer, in particular not provided with a backing layer made of polyethylene. As indicated above, the cleaning contact surface is made of a single foam material. Such backing or backer materials may be used in cleaning pads to impart the required rigidity to the cleaning pad. The cleaning pad of the invention however may have sufficient rigidity on its own, and the need for a backing layer of backer is

eliminated. The backing layer, or the backing layer, typically is a separate layer of relative rigid material arranged on one side of a cleaning pad, with the sole purpose of protecting the cleaning pad. The open cell flexible foam preferably has a pore distribution of between 40 and 90 pores per inch, in particular between 50 and 80 pores per inch. The pore

distribution may be a measure for the porosity or absorbency of the pad. The pore distribution may also be between 5 and 15 pores per inch, or more than 175 pores per inch. The open cell flexible foam preferably has a cell diameter between 25 and 75 microns or micrometre, alternatively the diameter is between 5 and 20 microns, or between 75 and 125 microns. The number of pores per inch and the size of the pores determine permeability. The provided range for the pore distribution is found to be particularly suited for cleaning escalator steps. The cleaning pad may for instance be used to clean an escalator while the escalator is moving or turning. The steps rise towards the top of the escalator, turn inwards and move down again on the inside of the escalator, not visible for people using the escalator. At the top of the escalator, steps are thus coming one after the other. The cleaning pad may be arranged at the top. The part of the escalator which forms the transition between the escalator steps and the top deck is called the comb. The required rigidity of the cleaning pad is such that the pad can be placed on top of the escalator, against the comb of the escalator, whereas the cleaning pad is not damaged on the comb upon the force of the moving escalator steps. The steps move sequentially underneath the cleaning pad, and the interlocking ridges and grooves clean each subsequent step.

The density of the cleaning pad may for instance be over 20 kilogram per cubic meter (or over about 1.25 pound per cubic foot), in particular over 30 kilogram per cubic meter (or over about 1.88 pound per cubic foot) , more in particular over 40 kilogram per cubic meter (or over about 2.5 pound per cubic foot), for instance measured according to IS0845:2006. In an embodiment the density of the cleaning pad is over 80 kilogram per cubic meter (or over about 5 pound per cubic foot), or even over 90 kilogram per cubic meter (or over about 5.6 pound per cubic foot).

A relative high density of the contact surface results in a tighter packed contact surface, able to withstand more forces which increases the cleaning and rubbing capacity of the contact surface of the pad, and the ridges thereof in particular. The density of the contact surface should, on the other hand, preferably be not so high that the ridges cannot deform slightly anymore, to accommodate possible variations in geometry between different escalator steps, and the threads thereof in particular.

The cleaning pad may comprising a connecting surface, arranged on an opposite side of the pad compared to the contact surface, for connecting the cleaning pad to an escalator cleaning head, wherein the connecting surface may be provided with coupling elements, preferably cooperating with complementary coupling elements on the escalator cleaning head. Typically, the contact surface of the cleaning pad is arranged towards the ground, or bottom, or towards the surface of the escalator steps to be cleaned, whereas the connecting surface is arranged towards the sky, or on top, towards the cleaning head. The coupling elements are preferably made in one piece with the cleaning pad, and are made of the same material. The connecting surface and the coupling elements allow the pad to be coupled or connected to another structure. This structure may thus be an escalator cleaning head, or be part of a cleaning system. In particular, the structure may be provided with a handle, to allow cleaning motions to be performed from a distance from the pad. Preferably, the coupling surfaces of the cleaning pad are embodied as recesses, for instance T-shaped recesses, and the cleaning head is provided with protruding elements, for instance T-shaped protrusions, which protruding elements lock into the recesses of the cleaning pad. The cleaning pad may thus slide onto the protrusions of the cleaning head.

The cleaning pad may further be arranged for cleaning risers of an escalator and/or arranged for cleaning ridges and/or grooves of a walking surface of an escalator. The walking surface of the escalator is typically a horizontal surface, whereas the risers for a mainly vertical surface. It may for instance be envisioned that the pad may be turned 90 degrees, or that the ends of the pads, perpendicular to the contact surface of the pad, is also provided with ridges as well.

The cleaning pad may be formed by mixing a poly-isocyanate compound and a polyol and/or a polyamine compound and allowing the compounds to react, wherein the poly-isocyanate compound preferably is a diisocyanate, preferably

difenylmethane-4,4'-diisocyanate (MDI), possibly also including additives like castor oil. The reaction is typically a polymerization reaction. Polyurethane foams may be formed by a reaction of these components. Isocyanates are generally very reactive materials. Polyols are polymers in their own right and have on average two or more hydroxyl groups per molecule. Polyether polyols are mostly made by co

polymerizing ethylene oxide and propylene oxide with a suitable polyol precursor. If water is present in the reaction mixture (it is often added intentionally to make foams), the isocyanate reacts with water to form a urea linkage and carbon dioxide gas and the resulting polymer contains both urethane and urea linkages. This reaction is referred to as the blowing reaction

The rigidity of the pad may be changed by the changing ratio of isocyanate to polyol. The required rigidity may for instance be achieved by increasing this ratio to over 0.25:1 , in particular over 0.33:1 . By increasing the amount of isocyanate, the amount of hard segments in polyurethane is increased. Alternatively, the amount of alcohol groups, or -OH groups, in the polyol may be changed. Polyols with high functionality result in rigid, more cross-linked polyurethane foams. For instance, the polyol may thus be a high functionality polyol, or a polyol with 3-8 hydroxyl groups per mol. In an embodiment, the functionality of the polyol, or the amount of alcohol, or -OH, groups of the polyol, is expressed as N. For instance, the polyol may be a trihydroxy polyether, and N would be three. The amount of polyol times N may be expressed as the functional amount polyol. The ratio of functional amount polyol to the amount of isocyanate may be between 1 :1 ,33 and 1 ,33:1 , preferably between 1 :1 ,25 and 1 ,25:1 . De amount of polyol may be tot total weight of polyol

compounds. The amount of isocyanate may be the total weight of isocyanate compounds. The cleaning pad may also comprise a foam stiffening agent, to stiffen to foam and increase its scrubbing and cleaning action or function. In an embodiment, the cleaning pad for instance comprises about 1 to 10% stiffening agent, more particular about 2 to 5%, more in particular about 3 to 4% stiffening agent. The higher the amount of stiffening agent, the more rigid the pad becomes. However, when providing more than the listed amounts, the strength of the pad is

compromised. A foam stiffening agent can for instance be FH-400, which is also known as a foam hardener.

The cleaning pad may also comprise a water absorbent chemical material. In particular when the cleaning pad is made to be relatively rigid, this greatly improves water absorbent properties of the cleaning pad. The chemical material may for instance be HP990.

Rigid polyurethane foam recipes may comprise a number of ingredients. Polyols for instance are a source of hydroxyl (OH) or other isocyanate reactive groups.

Processing and properties of the resultant foam can be markedly influenced by the choice of starting polyol structure. Polyols mainly used for PURs are low molecular weight hydroxyl terminated polyethers, polyesters and natural products (e.g. castor oil). Polyether polyols are produced by addition of 1 ,2-propylene oxide (PO) and ethylene oxide (EO) to the hydroxyl group (or amino groups) of low molecular weight molecules, usually by anionic chain mechanism. Polyester polyols are prepared by the polycondensation reaction of di-, or polycarbonic acid or their anhydrides (e.g. phthalic acid, phthalic anhydride) with di- and polyalcohols (e.g. ethylene glycol). Isocyanate may provide a source of NCO groups to react with functional groups from the polyol, water and other ingredients in the formulation. Typically for PURs the recipes provides an excess of isocyanate in order to obtain the desired final properties.

Also catalysts may be used. Of the many classes of compounds investigated, the amines and the organometallics have been found most useful. Various

combinations of catalysts are used in order to establish an optimum balance between the polymerization and the blowing reaction. The polymer and gas formation rates must be balanced so that the gas is entrapped efficiently in the gelling polymer and the cell-walls develop sufficient strength to maintain their structure without collapse or shrinkage. Catalysts are also important for assuring completeness of reaction or“cure” in the finished foam. The catalysts most commonly used are tertiary amines such as triethylamine, and alkali metal salts, e.g. potassium acetate. Some catalysts such as tertiary amines affect both the polymerization and the blowing reaction, while others like dibutyltin dilaurate promote primarily the polymerization reaction and chain propagation.

Additionally, blowing agents may be used producing a cellular structure in polymeric matrix via a foaming process. During the polymerization reaction they give rise to gas bubbles which inflate the polymer. Also surfactants may be used in producing rigid polyurethane foams, for instance nonionic, silicone-based surfactants which may stabilize cell walls.

In an embodiment, the foam ingredient comprises:

The polyether polyol may be polypropylene glycol. The polymeric polyol may be a trihydroxy polyether, is prepared by polymerization of glycerol with propylene oxide and ethylene oxide in the presence of a base catalyst. The polymeric polyol is preferably polyurethane resin POP 2045. Instead of the different polyols, the foam may also comprise 50-70% polyol, preferably 60-65%. All percentages are compared to total weight of the ingredients.

Open cell rigid polyurethane foams may also be made in known ways, as for instance disclosed in US5457138 or US5889067, to content of which with regard to Open cell rigid polyurethane foam formation is incorporated by reference herein.

According to the invention, the ingredients of the foam may be processed at room temperature and put into a tank. The liquid is subsequently sprayed into a mould, such as a u-shaped groove, at pressure (preferably at high pressure, pressure above atmospheric pressure to ensure mixing of the ingredients) and allowed to expand in the mould. The mould is slowly moved forward, to keep adding material at the spraying point. This move is preferably a constant move, to provide a consistent foam along the length thereof. The produced foam is then cured, for instance for 24 hours, to create a stable foam. Afterwards, the foam is cut at length.

The inlet opening of the vacuum unit may extend along substantially the complete front of the cleaning head. The cleaning head may be elongated, and the inlet opening of the vacuum unit may thus extends over substantially the complete width of the cleaning head. This allows for debris and dirt to be sucked from beneath the cleaning head over the complete width of the cleaning system. An exit opening, for connecting the vacuum unit to a vacuum source and removal of the debris and dirt may be provided centrally on the vacuum unit, and may be a single exit opening.

The invention further relates to a cleaning pad, a cleaning brush, a vacuum unit and a cleaning head for use in a cleaning system according to the present invention. Features contributed to these elements in regards to the cleaning system can thus be considered in their own right, separate from the cleaning system in full. These elements may be used and provided separately, and can be used to turn

conventional escalator cleaning systems in improved escalator cleaning systems. The invention thus for instance relates to a cleaning pad for an escalator or moving walkway, the cleaning pad comprising: a contact surface comprising ridges and/or grooves, for contacting ridges and/or grooves of the escalator or moving walkway, wherein at least the contact surface of the cleaning pad is made of a single absorbent material, which material is an open cell flexible foamed material, in particular a foamed polyurethane.

The invention will be elucidated on the basis of non-limitative exemplary

embodiments shown in the following figures, wherein:

- Figure 1 schematically shows a cleaning system according to the invention;

- Figure 2 schematically shows a cross section of the system of figure 1 ;

- Figure 3 schematically shows a variation of the system of figures 1 and 2, provided with a spray unit;

- Figure 4 schematically shows a variation on the system of figures 1 -3,

provided with two blocking elements;

- Figure 5 schematically shows a vacuum unit according to the invention;

- Figure 6 schematically shows a cleaning brush according to the invention;

- Figure 7 schematically shows a cleaning pad according to the invention; and

- Figure 8 schematically shows an embodiment of a cleaning head according to the invention.

Figure 1 schematically shows a cleaning system (1 ) according to the invention, in both a schematic view (left) and an exploded view (right). The cleaning system (1 ) comprises a cleaning pad (2) comprising a contact surface (3) for contacting the surfaces of the escalator or moving walkway to be cleaned, which is the bottom surface of the cleaning pad (2). The cleaning pad (2) also comprises a coupling surface (4), opposite the contact surface (3) and thus at the upper surface, for coupling the cleaning pad (2) to a cleaning head (5).

The system (1 ) further comprises a cleaning head (5) for holding the cleaning pad (2), comprising coupling means (6), for coupling the cleaning pad (2) to the cleaning head (5). These coupling means (6) are arranged on a surface of the cleaning head (5) directed towards the cleaning pad (2). The system (1 ) also comprises an attachment element (7), for attaching the cleaning head (5) to a broom (8).

The system (1 ) is further provided with a vacuum unit (9), arranged to be attached to a first side (A) of the cleaning head (2), in particular to the front side (A) of the cleaning head (2), comprising an inlet opening (10), aimed towards the surface of the escalator or moving walkway to be cleaned, and an outlet opening (11 ), opposite the inlet opening (10), for attachment to a vacuum source and for removal of elements sucked up by the vacuum unit (9).

The system (1 ) also comprises a cleaning brush (12), arranged to be attached to the first side (A) of the cleaning head (5) or to the vacuum unit (9), comprising a plurality of brushes (13), extending towards the surfaces of the escalator or moving walkway to be cleaned and arranged to contact ridges and/or grooves of the escalator or moving walkway.

The cleaning head (5) and the vacuum unit (9) are provided with mutually interacting first connecting elements (14) , for connecting the vacuum unit (9) to the cleaning head (2) and the vacuum unit (9) and the cleaning brush (12) are provided with mutually interacting second connecting elements (15) for connecting the vacuum unit (9) to the cleaning brush (12). Between the cleaning brush (12) and the vacuum unit (9) a rubber gasket (16) is provided. The cleaning brush (12) is provided with a connecting surface (17), for connecting the cleaning brush (12) to the vacuum unit (9) wherein the plurality of brushes (13) are attached to the connecting surface (17).

Figure 2 schematically shows a cross section of the system (1 ) of figure 1 , with on the left the cleaning brush (12). The same reference numerals as compared to figure 1 are used.

Figure 3 schematically shows a variation of the system (1 ) of figures 1 and 2, provided with a spray unit (18), mounted on a broom (8) of the system (1 ), for spraying a cleaning liquid on the cleaning pad (2) or onto to surfaces of the escalator or moving walkway to be cleaned. The spray unit (18) may for instance be a housing (18) for holding cleaning liquid. The cleaning head (5) may be provided with spray nozzles (19), for dispensing cleaning liquid. The same reference numerals as compared to figure 1 and 2 are used.

Figure 4 schematically shows a variation on the system (1 ) of figures 1 -3, provided with two blocking elements (2) for distancing the cleaning head (5) from combs of the escalator or moving walkway. The contact surface (3) of the cleaning pad (2) comprises ridges (21 ) and grooves (22), for contacting ridges and grooves of the escalator or moving walkway. The blocking elements (20) also comprise ridges (23) and grooves (24), which in figure 4 align with the ridges (21 ) and grooves (22) of the contact surface (3), as shown in the circle on the left or are arranged higher compared to the ridges (21 ) and grooves (22) of the contact surface (3), as shown in the circle on the right. The same reference numerals as compared to the previous figures is used.

Figure 5 schematically shows a vacuum unit (9) according to the invention in two perspective views. The same reference numerals as compared to the previous figures is used.

Figure 6 schematically shows a cleaning brush (12) according to the invention. The same reference numerals as compared to the previous figures is used.

Figure 7 schematically shows a cleaning pad (101 ) according to the invention. The pad (101 ) comprises a contact surface (102) comprising ridges (103) and/or grooves (104), for contacting ridges and/or grooves of an escalator or moving walkway. The pad (101 ) further comprises a connecting surface (105), arranged on an opposite side of the pad (101 ) compared to the contact surface (102), in this case the connecting surface (105) is on top, whereas the contact surface is at the bottom. The contact surface (105) is configured for connecting the cleaning pad (102) to an escalator cleaning head, wherein the connecting surface (105) is provided with coupling elements (106). The coupling elements (106) in figure 1 are embodied as recesses (106) in the connecting surface (105) of the cleaning pad (101 ). These coupling elements (106) preferably cooperate with complementary coupling elements on the escalator cleaning head. Alternatively, the coupling elements (106) are embodied as protrusions, and the recesses are arranged on the escalator cleaning head.

Figure 8 schematically shows a cleaning head (1 10) according to the invention, provided with a cleaning pad (101 ) as shown in figure 7. The coupling elements (106) of the pad (101 ) cooperate with complementary coupling elements (1 11 ), shown as protrusions (1 1 1 ) on the cleaning head (1 10). The head (110) is further provided with an attachment (112), to connect the head (110) to a handle (113) or broom (113). The head (110) fits into a saturation tub (114), that may for instance be filled with cleaning solution or water.