Title: Method of and means for treating a floor
Description of Invention
The present invention relates to the cleaning of floors and is concerned with the cleaning of floor surfaces which are relatively smooth, in contrast with floor surfaces presented by pile fabrics and other fibrous materials. Cleaning of relatively smooth floor surfaces typically includes rubbing to remove foreign matter from the surface and buffing to establish a shine or other uniform finish on the floor surface.
For cleaning relatively smooth floor surfaces, there are used polishing machines which rotate a pad in contact with the floor surface. Typically, the pad has a fibrous structure and is carried on a carrier which has an array of small hooks or other means for releasably retaining the pad on the carrier. To remove foreign matter from the surface, it is often necessary to employ a pad which has grains of an abrasive at the working surface of the pad, that is the surface which bears on the floor, during use. In this way, ingrained dirt can be removed from the floor. Furthermore, by means of an abrasive pad score marks can be removed from the floor surface. Pads with different abrasive grains are available so that relatively coarse abrasive pads can be used in some cases and relatively fine abrasive pads can be used in other cases.
The procedure for cleaning a floor surface typically involves nibbing the surface with an abrasive pad mounted on a polishing machine, removing the abrasive pad and replacing it with a non-abrasive pad and then rubbing the surface again with the non-abrasive pad. The use of the non-abrasive pad is necessary, in order to achieve a polished finish on the floor surface.
According to a first aspect of the present invention, there is provided a method of treating a surface wherein successive regions of the surface are each subjected to a succession of rubbing strokes and alternate ones of said
strokes are abrasive strokes, the intervening strokes being relatively non- abrasive strokes.
We have found that a succession of strokes in which abrasive strokes alternate with non-abrasive strokes removes foreign matter from a floor surface and achieves a polished finish on the floor. This is surprising, because we have previously found that a polished finish cannot be achieved by rubbing a floor surface with a pad which has abrasive particles at the working surface of the pad.
In performance of a method in accordance with the first aspect of the invention, the floor is preferably rubbed with a pad having at least one relatively abrasive region and at least one relatively non-abrasive region and said regions are moved alternately across a local region of the floor. Thus, the pad may be rotated by a known polishing machine.
According to a second aspect of the invention, there is provided a pad suitable for use in rubbing a floor and having a working surface which bears on the floor when the pad is in use, wherein the working surface includes one or more relatively abrasive regions and one or more relatively non-abrasive regions.
In the preferred pad, the. or e .. relatively abrasive region is spaced or are spaced from the periphery of the pad. The pad may have a single relatively non-abrasive region which surrounds the or each of the relatively abrasive regions.
The or at least one of the relatively abrasive regions of the working surface is preferably presented by an insert which is disposed in an opening formed in a main body of the pad. The insert may be an interference fit in the opening and is preferably freely removable from the opening. By describing the insert as being freely removable, we mean that the insert can be removed by hand without undue difficulty. However, interference between the insert and the main body of the pad is preferably such that the insert will not fall from the main body when the working surface of the pad is raised above the floor.
An insert which is removable from the main body of the pad can be replaced by a further insert. The further insert may have abrasive qualities different from those of the removed insert Thus, there may be provided for use with the main body a set of inserts having respective different grades or characteristics.
According to a third aspect of the invention, there is provided a pad suitable for use in rubbing a floor and having a working surface which bears on the floor during use of the pad, wherein the pad defines at least one opening extending into or through the pad from the working surface thereof. The opening can receive a suitable insert, for example an abrasive insert.
The opening is preferably spaced from both a centre of the pad and the periphery of the pad. The area of the opening is preferably within the range 2.5% to 10% of the area of the working surface of the pad.
The pad may have a number of openings. In this case, the aggregate area of the opemngs at the working surface is preferably within the range of 8% to 50% of the area of the working surface.
According to a further aspect of the invention, there is provided a set of pads comprising a larger pad according to the third aspect of the invention and a plurality of smaller pads, -each of a size to fit into the opening or a respective opening in the larger pad.
A pad embodying the second and third aspects of the invention and which is used in a method according to the first aspect will now be described, with reference to the accompanying drawing, which shows a perspective view of the pad.
The pad shown in the accompanying drawing has the form of a disc and is preferably cylindrical, having a diameter which is more than ten times the thickness of the pad. The pad is resiliency flexible and compressible. When the pad is in an unstressed condition, the pad has a substantially flat, circular surface 10 called herein the working surface. When the pad is in use, the working surface bears on the surface which is being treated by rubbing with the pad.
That surface of the pad which is opposite to the working surface 10 may be substantially identical with the working surface so that the pad can be used either way up.
The pad shown in the accompanying drawing comprises a main body 11 which defines the periphery of the pad and defines a number of openings which extend from the working surface either into the body or completely through the thickness of the body. In each of these openings, there is fitted a respective insert 12. There may be a single insert in a single opening of the main body. Preferably, a number of inserts are provided. By way of example, four inserts 12 are shown in the accompanying drawing. These inserts are spaced equally around a centre of the main body.
It will be noted that, in the example illustrated, each of the inserts is spaced from the periphery of the main body 11 and is also spaced from the centre of that body. The inserts may he somewhat nearer to the periphery of the main body than to its centre.
By way of example, circular inserts are shown in the accompanying drawing. The openings and the inserts may have other shapes, for example rectangular. Furthermore, differently shaped inserts may be incorporated in a single pad.
The pad illustrated in the accompanying drawing is intended primarily for use in the treatment of floors. The main body 11 is formed of materials used in the manufacture of known floor treatment pads. Generally, floor- treatment pads are formed of a mass of fibres- which are bonded into a coherent body by means of a binder. A variety of binders are used. The binder of the main body 11 is preferably a latex binder. The fibres and the binder are both preferably selected to impart resilience to the body 11.
Each of the inserts 12 also may be constructed a mass of fibres bonded into a coherent body by a suitable binder. The fibres and/or the binder may be the same as or different rom that used in the body 11. The fibres and/or the binder may be selected to provide that each insert has a stiffness somewhat greater than that of the body 11. The dimensions of each insert, relative to the dimensions of the corresponding opening in the body 11,
are such that the insert is an interference fit in the body 11. The thickness of each insert may be substantially equal to the thickness of the body 11, in a case where each opening extends completely through the thickness of the body.
Either that part of the working surface 10 which is presented by the body 11 or that part of the working surface which is presented by at least one of the inserts 12 has an abrasive character. In the example illustrated, that part of the working surface which is presented by the body 11 is non-abrasive and each of the inserts 12 has an abrasive character. As in known, abrasive floor-treatment pads, the abrasive character is imparted by the presence of grains of abrasive material at the working surface of each insert 12. Such abrasive particles are bound to the fibres of the pad by the binder. The abrasive particles may be incorporated in the binder, prior to binding of the fibres to one another. The size and other characteristics of the abrasive particles may be varied according to the type of floor on which the pad is to be used and other circumstances of use. Typically, the abrasive particles are present only at and immediately adjacent to the surface of each insert 12 and are not present throughout the entire thickness of the insert. The same or different abrasive particles may be present at the opposite working surface of the insert. Alternatively, each insert may have an abrasive character at one working surface and a non-abrasive character at the opposite working surface.
Each insert 12 is an interference fit in the corresponding opening in the body 11. Some resilient deformation of the body and/or of the insert may be necessary during insertion and removal of the insert from the body. The body grips the insert sufficiently to ensure that the insert will not fall from the body when the working surface of the pad is raised from a floor surface. The insert can readily be removed from the body 11 by hand. For example, if a portion of the body 11 immediately adjacent to an insert is compressed, the peripheral surface of the insert will be exposed. This facilitates grasping of the insert by hand and withdrawal of the insert. A replacement insert can be fitted by the application of gentle pressure to the insert. The peripheral surfaces of the inserts 12 and the corresponding boundary surfaces of the opemngs in the body 11 are substantially perpendicular to the working surface
of the pad, when the pad is unstressed. It would be within the scope of the invention for the peripheral surfaces of the inserts to be somewhat inclined to the working surface of the pad or of stepped form, in order to retain the insert more securely in the body 11.
We prefer to use removable inserts to provide the relatively abrasive regions of the working surface 10. It is then possible to substitute for the inserts further inserts having different characteristics. Furthermore, an insert which has become worn so that its abrasive character is impaired significantly can be replaced by a fresh insert without discarding the main body 11. However, it would be within the scope of the invention to provide a unitary pad having a working surface with at least one relatively abrasive region and at least one relatively non-abrasive region. For example, the pad may be formed as a single body of bonded fibre with abrasive particles bonded to the fibres in local regions only of the working surface of the pad. Alternatively, the pad may be constructed of a main body and inserts which are permanently bonded to the main body. It would also be within the scope of the invention for the main body 11 to have an abrasive character and the inserts to be relatively non-abrasive.
In a case where the main body of the pad has a non-abrasive character and the inserts are abrasive, the aggregate area of the relatively abrasive regions of the working surface of the pad is preferably within the range 2.5% to 50% of the area of the relatively non-abrasive region of the working surface. More preferably, the relatively abrasive regions have an aggregate area which is within the range 10% to 40% of the area of the non- abrasive region of the working surface. In a case where a number of inserts are provided in respective opemngs in the working surface, the area of each opening at the working surface is preferably within the range 2.5% to 10% of the relatively non-abrasive region of the working surface.
During use of the d, the pad is rotated with at least a part of the working surface in contact with the floor surface or other surface which is to be treated. The part of the working surface at which contact is established includes both abrasive and non-abrasive regions. Thus, a local region of the
surface which is being cleaned is subjected to a succession of rubbing strokes in which abrasive strokes alternate with non-abrasive strokes.
The features disclosed in the foregoing description, or the accompanying drawing, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.