GB2511854A - A machine for scrubbing or finishing floor surfaces - Google Patents

Abstract

A machine for scrubbing or finishing a floor surface comprises a front end and a rearward end, a workhead 12 at or towards the front end of the machine, an electric motor 35 arranged in use to drive the workhead 12 and disposed generally above said workhead 12, a set of wheels (9, fig 1) disposed rearwardly of the workhead 12 so that the weight of the device is supported by the workhead 12 and the wheels (9, fig 1) when the machine is located on a floor surface, the machine being rearwardly tiltable about the set of wheels (9, fig 1) so as to lift the front end and workhead 12 from the floor surface for access to the workhead 12. The machine is characterised in that the machine is provided with one or more liquid containers 22, 23 which extend between a front end region of the machine generally above the workhead 12 to a rear end region of the machine which is to the rear of the wheel tilt axis (9, fig 1), so that when the machine is sufficiently tilted a change in liquid distribution towards the rear of the container occurs which provides a shift in the centre of gravity of the liquid from a region in front of the tilt axis to a region behind the wheel tilt axis, thereby serving to help urge or maintain the machine in the tilted orientation.

Description

A machine for scrubbing or finishing floor surfaces This invention relates to a machine for scrubbing or finishing a floor surface of the kind which comprises a carriage adapted for translational movement over a floor surface, a workhead mounted on the carriage and an electric motor carried by the carriage and arranged in use to drive the workhead. Such a machine will be referred to as "a machine of the kind

described" in the remainder of this description.

The workhead may include a brush or pad carrier which is provided with means for securing a brush or pad to it so that, in use of a machine of the kind described, the brush or pad is maintained in working contact with the floor surface. The carriage may also include a pair of rear transit wheels which are mounted on an axle towards the rear of the carriage. The weight of the machine is supported on the rear transit wheels and on the workhead whilst the machine is in use. Sometimes machines include front wheels, especially where the weight of the machine is such that the workhead would otherwise be overloaded.

Such machines may also comprise reservoirs for supplying a cleaning liquid, e.g. water, a solution or polish, to the floor to be treated with the brush or pad and for collecting dirty liquid sucked up from the floor. One such receptacle may serve as a reservoir for the cleaning liquid and another as a liquid collecting receptacle for the dirty liquid.

With machines of the kind described it is desirable to be able to access the underside of the machine, e.g. for workhead maintenance, repair or replacement purposes. Our patent publication US5477578 discloses a machine in which the workhead (and drive motor) are biased to flip to an orientation in which the workhead may be accessed when the machine is tipped backwards.

Battery operated machines of the kind described all of necessity incorporate fairly substantial battery packs which are also quite heavy. Our patent publication U62005/246845 discloses a machine in which the position of the battery may be shifted to vary the weight acting on the workhead. The weight of the battery may be used to urge the workhead into intimate contact with the floor surface to be treated, so as to enhance the treatment effect. Mains operated machines of the kind described do not carry the associated weight of the battery packs.

An object of this invention is to provide means for facilitating access to the underside of the machine so that, for example, a workhead brush or pad can be easily replaced, repaired or maintained. It is also an object to provide a mains-operated machine in which the loss of battery weight over the cleaning head does not reduce cleaning performance.

Broadly, this invention comprises a system by which the centre of gravity of a machine of the kind described can be varied by tilting the machine and redistributing liquid contained in a fluid container so that the machine may rest in a manner that facilitates access to its underside.

According to one aspect of the invention there is provided a machine for scrubbing or finishing a floor surface having a front end and a rearward end, a workhead at or towards the front end of the machine, an electric motor arranged in use to drive the workhead and disposed generally above said workhead, a set of wheels disposed rearwardly of the workhead so that the weight of the device is supported by the workhead and the wheels when the machine is located on a floor surface, the machine being rearwardly tiltable about the set of wheels so as to lift the front end and workhead from the floor surface for access to the workhead.

The invention is characterised in that the machine is provided with one or more liquid containers which extend between a front end region of the machine generally above the workhead to a rear end region of the machine which is to the rear of the wheel tilt axis. When the machine is sufficiently tilted a change in liquid distribution towards the rear of the container occurs which provides a shift in the centre of gravity of the liquid from a region in front of the tilt axis to a region behind the wheel tilt axis, thereby serving to help urge or maintain the machine in the tilted orientation.

In this way, when the machine is tilted, liquid shifts rearwardly. If sufficient liquid is present, the machine will tend to stay in the tilted configuration. If insufficient liquid is present, the tilt may not be stable, but the weight of shifted water will tend to facilitate the tilt, thereby easing the tilting by the machine operator. As an example, the tilt may be stable if the one container is filled with liquid to at least 50% of volumetric capacity.

When the machine is un-tilted, the centre of gravity of the liquid may be distributed to the front of the tilt axis, thereby to help urge the workhead into contact with the floor. This is particularly helpful for mains powered machines in which the weight of batteries is not available to serve this purpose.

The tilted orientation typically represents a configuration in which the weight of the machine is shared between the wheels and a floor-contacting region of the machine which is disposed to the rear of the tilt axis and which comes into contact with the floor when the machine is sufficiently tilted, which configuration is stable provided that sufficient liquid is present in the containers.

At least one liquid container may extend substantially along one side region of the machine. Preferably at least one liquid container extends substantially along both side regions of the machine, and preferably around an internal perimeter of the machine.

In a preferred arrangement, the machine has at least two liquid containers, one which is a clean reservoir adapted to feed liquid a dispensing apparatus and the other which is a dirty reservoir adapted to be fed by a liquid collection apparatus. One of the containers is preferably disposed generally above the other, preferably the dirty reservoir is above the clean reservoir.

At least one of the containers preferably has a generally horseshoe plan configuration in which the tails of the horseshoe extend rearwardly and the front region of the horseshoe loops around the drive motor at the front region of the machine.

One of the containers has a rear base region which is inclined towards the front end of the machine so that liquid in the reservoir tends to flow towards the front end of the container when the machine is un-tilted.

At least one liquid container may have a rear roof portion which rises so as to provide a volume in which liquid in the reservoir can be accommodated when the machine is tilted.

In a preferred embodiment the clean reservoir is disposed below the dirty reservoir, and said inclined base region is provided in the dirty reservoir and said rising roof portion in provided in the clean reservoir. The said inclined base region and rising roof regions may be configured to have juxtaposed and complementary profiles, which provided space efficiency.

The present invention has particular application in mains powered cleaning or scrubbing machines. The invention could however be applied to battery powered machines.

The machine is typically provided with a generally upstanding handle for directing and facilitating tilting of the machine. This may conveniently be of a T-bar configuration with operational controls provided. The handle may be foldable to facilitate storage of the machine when not in use.

The set of wheels may typically be two laterally spaced apart transit wheels. The could however be a single roller or rollers. Additional wheels, rollers or cartors may be provided, such as to help support the weight of the workhead in large machines, or to support a squeegee suction fluid collection apparatus.

The machine is typically tilted about the transit wheel axis. In theory the invention could be used without wheels provided that a floor-engaging pivot means (such as a lateral bar or beam) is present which permits tilting of the machine. However in most commercial machines the pivot will be provided by a set of wheels.

The machine may be mains operated, in which case the invention may be particularly beneficial in being able to compensate for the absence of heavy battery packs.

Following is a description by way of example only and with reference to the drawings of one form of machine for scrubbing or finishing floor surfaces in which this invention is embodied.

In the drawings:-Figure 1 is a side view of a machine in accordance with the invention, orientated as it would be in use, with a cut-away side to show internal liquid reservoirs.

Figure 2 is a view similar to Figure 1 but with the machine in a tilted orientation.

Figure 3 and 4 are schematic side views of the liquid reservoirs shown in figures 1 and 2.

Figure 5 is a schematic representation of the general cross-sectional plan configuration of each of the liquid reservoirs.

Figure 1 shows a machine 10 for scrubbing a floor surface which includes a carriage (not shown) and a housing. The carriage is supported towards its rear on two spaced apart transit wheels 11 which are mounted at either end of an axle 9. A workhead assembly 12 is carried at the front of the carriage. The workhead assembly 12 includes a brush housing 13 which is formed with a depending peripheral skirt and a detachable annular brush 15. An electric motor (not shown) is mounted in the carriage above the brush housing 13. The electric motor is coupled by suitable mechanical gearing (not shown) to rotate the brush 15 about a vertical axis. Figure 1 shows the brush 15 in engagement with the floor surface 20 which is the position it adopts when the machine 10 is in use to scrub the floor surface 20. In this position the weight of the machine 10 is supported by the rear transit wheels 11 and the brush 15.

The brush housing 13 trails a squeegee suction collectorl 6 at its rear.

The collector is supported by a castor wheel 19. The collector is of conventional design, so is not further described herein.

Mains electricity powers the electric motor of the workhead assembly 12 and a suction pump (not shown) which is part of an internal the fluid handling system of the machine 10.

The machine has hollow liquid containers which serve as reservoirs. There is an upper reservoir 22 best seen in figure 3 which is adapted to receive dirty liquid pumped to it from the floor by the suction collector. A bottom reservoir 23 is for cleaning liquid, typically water and detergent solution or polish which is for supply to the floor surface 20 to be treated with the brush 15 of the workhead assembly 12.

The upper reservoir has a rear floor portion 30 which falls towards the front region 29 of the reservoir. As can been seen from figure 3, this ensures that dirty liquid collected 36 tends to gather over the workhead.

The bottom reservoir has a rising rear roof portion 31, which provides an expansion volume 32 in which cleaning liquid 37 is accommodated when the machine is tilted (see figure 4). In normal use most of the clean and dirty liquid is over the workhead, which is thereby urged into intimate contact with the floor 20 to be cleaned.

As shown in figure 5, the reservoirs each have a generally horseshoe configuration, which is to say that they have a front region 38 which loops around a motor housing 35, and rear side regions (or tails) 39 which extend to the rear of the machine.

Referring back to figures 1 and 2 a rear flat portion 24 of the machine housing is profiled to engage the ground when the machine 10 is tilted as shown in figure 2 by raising the front of the machine by tilting about the axle pivot 9 provided by the transit wheel set. See also figures 3 and 4. a

The carriage has a handle 25 which is mounted at the upper rearward part of the machine. The handle 25 has an upwardly and rearwardly extending elongate shaft 26 with a handle bar 27 fastened to its upper end. The handle is hinged at its lower end so that the handle can be pivoted forwards (not shown) and onto the housing for more convenient storage of the machine. The upper part of the handle has conventional controls for operating the machine (not visible).

An operator of the machine can use the handle 25 to rock the carriage backwards on the transit wheels 11, thereby to raise the front end of the carriage with respect to the floor surface 20 and to lift the workhead assembly 12 and bring the rear section 24 into engagement with the ground. Such movement of the machine will redistribute liquid contained within the reservoirs 23 and, provided that there is sufficient liquid therein, the machine's overall centre of gravity will change to the extent that it can rest stably on the flat portion 24 (see Figure 2). With the machine resting stably on flat portion 24 an operator is then able to, for example, clean or replace the workhead brush.

Claims (13)

1. Claims 1. A machine for scrubbing or finishing a floor surface having a front end and a rearward end, a workhead at or towards the front end of the machine, an electric motor arranged in use to drive the workhead and disposed generally above said workhead, a set of wheels disposed rearwardly of the workhead so that the weight of the device is supported by the workhead and the wheels when the machine is located on a floor surface, the machine being rearwardly tiltable about the set of wheels so as to lift the front end and workhead from the floor surface for access to the workhead, characterised in that the machine is provided with one or more liquid containers which extend between a front end region of the machine generally above the workhead to a rear end region of the machine which is to the rear of the wheel tilt axis, so that when the machine is sufficiently tilted a change in liquid distribution towards the rear of the container occurs which provides a shift in the centre of gravity of the liquid from a region in front of the tilt axis to a region behind the wheel tilt axis, thereby serving to help urge or maintain the machine in the tilted orientation.
2. 2. A machine as claimed in claim 1 wherein the tilted orientation is a configuration in which the weight of the machine is shared between the wheels and a floor-contacting region of the machine which is disposed to the rear of the tilt axis and which comes into contact with the floor when the machine is sufficiently tilted, which configuration is stable provided that sufficient liquid is present in the containers.
3. 3. A machine according to claim 1 or 2 wherein at least one liquid container extends substantially along one side of the machine.
4. 4. A machine according to any preceding claim wherein at least one liquid container extends substantially along both sides of the machine, preferably around an internal perimeter of the machine.
5. 5. A machine according to any of the preceding claims comprising at least two liquid containers, one which is a clean reservoir adapted to feed liquid a dispensing apparatus and the other which is a dirty reservoir adapted to be fed by a liquid collection apparatus.
6. 6. A machine according to claim 5 wherein one of the containers is disposed generally above the other.
7. 7. A machine according to claim 5 or claim 6 wherein at least one of the containers has a generally horseshoe plan configuration in which the tails of the horseshoe extend rearwardly and the front region of the horseshoe loops around the drive motor at the front region of the machine.
8. 8. A machine according to any of claims 5 to 7 wherein at least one of the containers has a rear base region which is inclined towards the front end of the machine so that liquid in the reservoir tends to flow towards the front end of the container when the machine is un-tilted.
9. 9. A machine according to any of claims 5 to 8 wherein at least one liquid container has a rear roof portion which rises so as to provide a volume in which liquid in the reservoir can be accommodated when the machine is tilted.
10. 10. A machine according to claims 8 and 9 wherein the clean reservoir is disposed below the dirty reservoir, and said inclined base region is provided in the dirty reservoir and said rising roof portion in provided in the clean reservoir.
11. 11. A machine according to claim 10 wherein the said inclined base region and rising roof regions are configured to have juxtaposed and complementary profiles.
12. 12. A machine according to any preceding claim which is adapted to be powered by mains electricity via an electrical cable.
13. 13. A machine according to any preceding claim further comprising a generally upstanding handle for directing and facilitating tilting of the machine.