GB2305112A

GB2305112A - A floor cleaning apparatus

Info

Publication number: GB2305112A
Application number: GB9518861A
Authority: GB
Inventors: Christopher Robert Duncan; Michael Edward Gailes
Original assignee: Numatic International Ltd
Current assignee: Numatic International Ltd
Priority date: 1995-09-14
Filing date: 1995-09-14
Publication date: 1997-04-02
Also published as: GB9518861D0

Abstract

A floor cleaning apparatus comprising motor means, supporting means 30 which reduces the load requirements of the motor and preferably an annular brush 42 for agitating the floor surface. The supporting means may be a plate or hub 34 which supports at least part of the weight of the apparatus allowing the brush to free-float on the surface that is to be cleaned. Biasing means which urge the brush to the cleaning surface may be provided. Such biasing may be springs 45 or additional masses (not shown) that can be added to the annular brush. Further cleaning fluid supply means and vacuuming means to remove dirt may be provided.

Description

This invention relates to the cleaning of surfaces, and in particular to apparatus for cleaning by scrubbing, brushing or polishing. The invention has particular reference to apparatus for use in carpet cleaning.

Industrial floor polishing and carpet cleaning and shampooing is presently carried out by machines equipped with one or more brushes which rotate about an axis perpendicular to the floor or carpet concerned. The brushes are typically disc shaped, having a lower surface covered in bristles or filaments which confront the surface to be cleaned. The weight of a machine is supported by the brush (or brushes) uniformly over the contact area. The weight forces the filaments or bristles into intimate contact with the surface and ensures that, during operation, there is good agitation of the surface or carpet concerned.

For efficient cleaning a large area of brush is desirable to speed up the cleaning process. A large brush, however, exerts a very high resistance to rotation when in contact with a surface, and this is especially so in the case of carpet cleaning where the brush bristles intermesh with the carpet tufts. As a consequence very powerful motors Attempts to use cheaper, lightweight, and less powerful motors have failed because the resistance to rotation of a brush is too high, even under the reduced contact pressure afforded by a lighter motor. Because of this, the application of such cleaning machines has been limited to industrial use by, for example, contract cleaners, where the large size, mass and cost of the machines is acceptable.

There is a need for a lightweight cleaning apparatus, which also has reduced bulk, power consumption and cost, and which therefore may have domestic application.

According the present invention there is provided apparatus for the cleaning of a surface, which apparatus comprises motor means adapted to move agitation means relative to, and in contact with, said surface, thereby to effect cleaning of the same, wherein the agitation means is driven via an intermediate support means adapted to support, during use, at least part of the weight of said apparatus on the surface, characterised in that the agitation means are adapted to free-float on the surface Hence the contact pressure exerted by the agitation means on the surface may be completely or partially independent of the weight of the rest of the apparatus. In this way the agitation means do not have to support the full weight of the apparatus, and therefore the contact loading of the agitation means can be reduced.This means that a reduced force is required to move the agitation means relative to the surface, and less powerful, lightweight motor means may be used.

In addition, if the loading on the motor means caused by the agitation means is too severe, for example if a carpet is too thick, the agitation means can simply rise from the carpet to reduce the load automatically. The free-floating agitation means thereby ensures that the apparatus can be used on a wide range of surfaces without overloading the motor means. A cleaning apparatus according to the present invention may be used on a variety of surfaces without the need for very powerful motors. Furthermore the contact pressure of the agitation means may be varied independently of the weight of the apparatus.

may be provided with biasing means adapted to bias the agitation means against the surface to be cleaned.

The biasing means may be operative between the agitation means and the support means thereby to spread the weight of the apparatus between the agitation means and the support means respectively.

In another embodiment the biasing means may include or comprises the weight of the agitation means. In this case the degree of biasing may be varied by varying the mass of the agitation means.

The motion of the agitation means may be rotation.

Rotation, in this embodiment, means rotation about an axis perpendicular to the surface. Rotation has the advantage of being easily implemented by rotary motors, such as electric motors.

The agitation means comprises one or more circular or annular brush member. Circular or annular brushes, when rotated, produce good, uniform agitation of the surface in contact.

The support means may comprise a hub to the brush member, and the hub is adapted to rotate with the brush member.

In this way the hub allows easy motion across the surface, with no static friction to be overcome.

In another embodiment the brush member free-floats on the hub, the arrangement being such that the brush member may move relative to the hub; closer to, or away from, the surface to be cleaned. The biasing means may be operative between the hub and the brush member, the arrangement being such that the brush member is urged against the surface to be cleaned. In this way the weight of the apparatus may be exerted against the brush member, with the proportion of weight taken by the brush member varying according to the degree of biasing.

Typically the biasing means is one or more compression springs, but may be one or more tension springs.

Alternatively, the biasing means may be one or more weights added to the brush member. Hence gravity acting on the mass of the brush member urges the brush member against the surface. In this way the contact pressure of the brush member on the surface may be varied according to the effective mass of the brush member.

In another aspect the biasing means may be a combination of springs and weights.

Typically, the motor means comprises an electric motor, with or without gear train. The hub preferably includes a smooth contact plate adapted to contact the surface to be cleaned. A smooth contact plate provides little resistance to motion, and evenly spreads the contact load.

The surface to be cleaned may, of course, be any floor surface, but the apparatus is particularly suited for use on carpets.

The apparatus may be combined with, or provided with, vacuuming means provided to suck dirt and debris from the surface as it is cleaned. Shampooing means may be provided which are adapted to introduce fluid onto the surface to be cleaned, thereby to enhance the cleaning process. The fluid is typically water to which detergent is added. When utilised in conjunction with the shampooing means, the vacuuming means may be adapted to lift used cleaning fluid from the surface and to store or filter used fluid within the apparatus.

The following is a description by way of example only and, with reference to the accompanying drawings, of methods of carrying the invention into effect.

Figure 1 is a diagrammatic representation of a cleaning machine according to an embodiment of the present invention.

Figure 2 is a representation of a cleaning head for the machine of figure 1.

Figure 3 is a representation of an alternative cleaning head for the machine of figure 1.

A carpet cleaning apparatus 10 in accordance with the present invention is shown in figure 1. The apparatus is disposed for translational movement over a carpet 2 having tufts 3 which are each made up of a bundle of fibre strands (not shown).

The cleaning apparatus 10 has a housing 11 having a cylindrical sidewall 12 which is closed at its upper part by circular top 12. The lower extremity of wall 12 carries an expanded portion 14 adapted to accommodate a workhead indicated generally at 20. Expanded portion 14 is pierced in its rearward part to accommodate an axle 15 which extends from the left hand side of the apparatus to the right hand side. The axle 15 carries a pair of wheels 16. One wheel is attached to the left hand end of the axle and the other is attached to the right hand end of the axle. The wheels are spaced from the surface of the carpet when the apparatus is in its operative disposition upon the carpet surface.

The top surface 13 of the housing 11 has a central recess 17 adapted to receive the bottom end of a tubular handle 18. A pin 19 pierces the left and right hand sides of the recess via a corresponding hole (not shown) in the bottom end of the handle so that the handle 18 is movably attached to the housing. The pin 19 allows the handle 18 to be moved in a limited arc of which the pin is the axis of rotation. The bottom end of the handle is provided with a locking mechanism (not shown) which allows the handle to be selectively locked in (and released from) a desired position along the arc of rotation. The handle 18 extends away from the housing to a distal end (not shown). The distal end has a hand grip which is provided with an on/off switch convenient for manipulation by a user and which allows the operator to activate or deactivate the apparatus.

The housing 11 accommodates internally thereof an electric motor 21 which drives a spindle 22 which extends downwardly thereof and carries at its lower end work head 20. The motor is electrically connected (not shown) via the handle-mounted on/off switch and to a mains power supply.

The workhead 20 is secured to the spindle 22 for rotation therewith and has a disc shaped base 20 (see figure 2) which is coaxial with, and distal from, the spindle and has a top surface 31 contiguous with the spindle. The base has a bottom surface 32 to which is attached an annular spacer ring 33 which extends about the periphery of the surface. The spacer ring separates the base 30 from > disc-shaped metal hub 34. The hub 34 has a top surface 35 around the periphery of which are four vertically upstanding circumferentially spaced pegs 40.

The pegs 40 between them carry for rotation therewith an annular brush member 42. Each peg is aligned with, and pierces, a hole 41 in the inner periphery of brush member 42.

Each hole is sized to allow the brush member to move substantially vertically up or down with respect to the pegs and hub. Each peg has a stopper washer 43 around the top end of the peg by means of a bolt 44 which threadably engages a bore in the end of the peg. Each stopper is adapted to retain a compression spring 45 which is carried on the peg and extends between the respective stopper and corresponding hole in the brush member to bias the latter downwardly with respect to the hub.

The brush member has an under surface 46, the outer part of which carries downwardly protruding nylon bristles 47.

The inner part of said under surface is stepped to provide an annular recess 48 which is of sufficient diameter to allow the top surface 35 of the hub to encroach into the recess at the downwards extremity of the brush member's movement relative thereto. The hub 34 has a generally smooth bottom surface 36 which is rounded at the outer periphery to facilitate sliding over the carpet tufts.

In position upon the carpet, the bottom surface 36 contacts the tufts and carries a substantial portion of the weight of the apparatus. The bristles contact the carpet and elastically deform to urge the brush member to slide upwards on the pegs against the spring loading.

The compliance of the springs 45 and the length and density of the bristles 47 may each be altered to change the local contact pressure and required severity of the cleaning process. The exact specification depends upon the carpet to be cleaned.

An alternative embodiment of the work head is shown in figure 3 in which a disc shaped base 50 is disposed coaxially with the spindle (shown in figure 1) and has a top surface 51 which engages the spindle. The base has a bottom surface 52 to which is attached an annular spacer ring 53 which extends around the periphery of the surface. The spacer ring separates the base 50 from a disc-shaped metal hub 54. The hub 54 has a top surface 55 along the periphery of which four vertically upstanding pegs 60 are provided to carry an annular brush member in the manner described with reference to figures 1 and 2. In place of the springs 45 the brush member top surface 55 is adapted to carry two annular rng masses 66,67 which serve to bias the brush member downwardly under the influence of gravity.

In position upon the carpet, the bottom surface 71 contacts the tufts and takes a substantial portion of the weight of the apparatus. The bristles contact the carpet and elastically deform under the weight of the ring masses which bias the brush member against the surface.

Size and number of the masses as well as the length and density of the bristles 69 may be altered to change the local contact pressure and required severity of the cleaning process. The exact specification depends upon the carpet to be cleaned.

In use, whether equipped with a cleaning head as shown in figure 2 or in figure 3, the apparatus is placed upon the carpet to be cleaned so that the hub of the workhead supports all, or the greater part, of the weight of the apparatus. Sweeping is initiated by the operator switching the switch on, and continues until the switch is switched off. A soiled carpet typically has particulate matter in between or on the tufts of the carpet, and grime embedded in the tufts and strands.

Sweeping dislodges particulate dirt and scrubs the tufts to help remove embedded grime. A cleaning fluid is used to remove/dissolve and entrain dirt from the carpet, which fluid is subsequently removed from the carpet surface. Hence the apparatus may have a fluid reservoir (not shown in the figures) containing water and detergent. The reservoir is adapted, in use, to introduce fluid and detergent onto the region to be swept. The fluid penetrates the tufts and strands of the carpet by capillary action, accelerated by the agitation caused by the sweeping. The detergent dissolves and lifts dirt and grime from the soiled carpet strands, aided by the scrubbing contact of the bristles. Particulate matter, and dirt in solution is then lifted from the surface by a vacuum head (not shown) or subsequently by a separate vacuum cleaner.

In use the handle (15 in figure 1) is inclined rearwardly so that the distal end of the handle which carries the hand grip corresponds approximately to the waist height of the operator. Should the operator wish to move the apparatus to a different carpet surface the handle may be released from its locked position so that it can be rotated upwards to the vertical where it is re-locked.

In this position the operator may then lower the handle to lever the apparatus so that the housing front end lifts from the surface by rotation to bring the wheels into contact with the floor. In this orientation the brush bristles will not contact the surface and the apparatus may be wheeled without hindrance to another cleaning site.

Claims

1. Apparatus for cleaning of a surface, which apparatus

comprises motor means adapted to move agitation means relative to, and in contact with, said surface, thereby to effect cleaning of the same, wherein the agitation means is driven via an intermediate support means adapted to support, during operation, at least part of the weight of said apparatus, characterised in that the agitation means is adapted to free-float on the surface to be cleaned, and in that the support means are adapted to support, during operation, substantially all the remaining weight of the apparatus.

2. Apparatus as claimed in claim 1 characterised in that the agitation means is provided with biasing means adapted to bias the agitation means against the surface to be cleaned.

3. Apparatus as claimed in claim 2 characterised in that the biasing means is operative between the agitation means and the support means thereby to spread the weight of the apparatus between the agitation means and the support means respectively.

15

4. Apparatus as claimed in either one of claims 2 and 3 characterised in that the biasing means includes or comprises the weight of the agitation means.

5. Apparatus as claimed in claim 4 characterised in that the degree of biasing may be varied by varying the mass of the agitation means.

6. Apparatus as claimed in any preceding claim, characterised in that the motion of the agitation means is rotation.

7. Apparatus as claimed in any preceding claim characterised in that the agitation means comprises one or more circular or annular brush member.

8. Apparatus as claimed in claim 7 wherein the support means comprises a hub to the brush member.

9. Apparatus as claimed in claim 8 characterised in that the brush member free-floats on the hub, the arrangement being such that the brush member may move relative to the hub; closer to, or away from, the surface to be cleaned.

10. Apparatus as claimed in claim 9 characterised in that the biasing means are operative between the hub and the 16 brush member, the arrangement being such that the brush member is urged against the surface to be cleaned.

11. Apparatus as claimed in claim 10 characterised in that the biasing means is one or more compression springs.

12. Apparatus as claimed in claim 9 characterised in that the biasing means is one or more weights added to the brush member.

13. Apparatus according to any one of claims 8 to 12 characterised in that the hub includes a smooth contact plate adapted to contact the surface to be cleaned.

14. Apparatus as claimed in any preceding claim characterised in that the motor means comprises an electric motor, with or without gear train.

15. Apparatus according to any one of the preceding claims wherein the surface to be cleaned is a carpet.

16. Apparatus according to any one of the preceding claims characterised by vacuuming means provided to remove dirt and debris from the surface.

17 17. Apparatus according to any one of the preceding claims characterised by shampooing means adapted to introduce fluid onto the surface to be cleaned, thereby to enhance the cleaning process.

18. Apparatus as hereinbefore described with reference to, or as shown in, the figures of the drawings.