WO2001095781A1

WO2001095781A1 - Suction sweepers

Info

Publication number: WO2001095781A1
Application number: PCT/GB2001/002556
Authority: WO
Inventors: John Brian Lund
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-10
Filing date: 2001-06-11
Publication date: 2001-12-20
Anticipated expiration: 2002-12-10
Also published as: GB0014148D0; AU2001264070A1

Abstract

A suction sweeper 1 is designed for road and/or pavement (sidewalk) use. A fan 5 is connected by a suction duct 6 to a suction head 7. Debris is entrained with air entering the suction tube 6, and travels past the fan 5 to a collection bag 9 in a collection chamber 8. Debris is collected in the bag 9, which has a degree of porosity, to allow the air to be exhausted from the chamber 8. The exhaust air from the chamber 8 is led via an exhaust duct 10 back to the suction head 7, where it is again sucked into the suction duct 6, to be recirculated through the suction system and collection chamber 8. There is no need to provide elaborate filtering systems for the exhaust air from the collection chamber 8, since most dust particles entrained in the exhaust air will tend to be sucked back into the suction tube 6, and be circulated again through the collection chamber 8.

Description

SUCTION SWEEPERS

This invention relates to suction sweepers, and is concerned particularly although not exclusively with suction sweepers for road or pavement (sidewalk) use.

A problem with existing suction sweepers is that significant air filtering systems have to be provided, to remove dust particles from air exhausted into the atmosphere. This involves initial expense in construction of the suction sweeper, and continuing expense in maintenance and cleaning of the filtering system.

Preferred embodiments of the present invention aim to provide suction sweepers that may be improved in this respect.

According to one aspect of the present invention, there is provided a suction sweeper comprising a suction source, a suction head connected with the suction source, and a collection chamber connected with the suction head, such that, in use of the sweeper, debris in the vicinity of the head is sucked into the head and from there into the collection chamber: wherein air from the collection chamber is exhausted via an exhaust duct to the suction head, to be recirculated through the collection chamber.

Substantially all of the air from the collection chamber may be exhausted via the exhaust duct to the suction head, to be recirculated through the collection chamber. By "substantially all", is meant all air other than that that may escape by unintentional leakage due to imperfections in the suction system.

Such a suction sweeper may further comprise recirculation control means for selectively diverting airflow in the exhaust duct between a recirculation path in which the air is directed to the suction head, to be recirculated through the collection chamber, and a non-recirculation path in which the air is exhausted to atmosphere.

Said recirculation control means may be controllable to provide adjustable proportions of air which are directed respectively to said recirculation and non-recirculation paths.

A suction sweeper as above may further comprise diverting means for selectively diverting airflow in the exhaust duct between a direct path in which the air is directed to the suction head, to be recirculated through the collection chamber, and an indirect path in which the air is directed to the suction head by a route that is less direct than that afforded by said direct path, thereby to reduce potential blow-away of debris in the vicinity of the suction head.

Said diverting means may be controllable to provide adjustable proportions of air which are directed respectively to said recirculation and non- recirculation paths.

A suction sweeper as above may further comprise a cowl in the vicinity of the suction head, to assist airflow into the suction head.

A suction sweeper as above may further comprise first and second cowls in the vicinity of the suction head, to assist airflow into the suction head, the second cowl being closer to the suction head than said first cowl.

Preferably, said first cowl provides at least part of said indirect path and said second cowl provides at least part of said direct path.

Said cowl or one of said cowls may be defined by at least part of an assembly for mounting rotatable brushes in the vicinity of the suction head.

Said cowl or one of said cowls may be defined by at least part of a chassis of the suction sweeper. Preferably, a cyclone device is mounted at least partially in said collection chamber, to cause particles of debris to fall into a collection receptacle.

A suction sweeper as above may further comprise a removable receptacle arranged to collect debris entrained in the air passing through the collection chamber.

Said removable receptacle may comprise a bag.

Preferably, said removable receptacle comprises a wheeled bin.

A suction sweeper as above may be designed for road or pavement (sidewalk) use.

A suction sweeper as above may be mounted on road wheels.

A suction sweeper as above may be provided with a steering system for said road wheels.

A suction sweeper as above may be provided with a seat for a driver of the sweeper.

A suction sweeper as above may further comprise one or a plurality of brushes for sweeping debris towards the vicinity of the suction head.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which:

Figure 1 shows one example of a suction sweeper according to one embodiment of the invention; Figure 2 shows another example of a suction sweeper according to another embodiment of the invention; and

Figure 3 is an exploded view of a detail of the suction sweeper of Figure 2.

In the figures, like reference numerals denote like or corresponding parts.

The suction sweeper 1 that is shown in Figure 1 is designed for road and/or pavement (sidewalk) use, being mounted on road wheels 2. The sweeper 1 is provided with a seat 3 for a driver, who may steer the front road wheels 2 by means of steering wheel 4.

A suction system within the sweeper 1 comprises a fan 5 which is connected by a suction duct 6 to a suction head 7. The suction head 7 is arranged to pick up debris form the road or pavement, as the sweeper 1 moves along. Typically, the suction head 7 is provided with brushes - for example, integrally, before and/or after the head 7, to sweep the road or pavement. Debris is entrained with air entering the suction tube 6, and travels past the fan 5 to a collection chamber 8, where a collection bag 9 is mounted on the end of a duct leading from the fan 5. Debris entrained in the air entering the chamber 8 is collected in the bag 9, which has a degree of porosity, to allow the air to be exhausted from the chamber 8.

The exhaust air from the chamber 8 is led via an exhaust duct 10 back to the suction head 7, where it is again sucked into the suction duct 6, to be recirculated through the suction system and collection chamber 8.

In this simple configuration, there is no need to provide elaborate filtering systems for the exhaust air from the collection chamber 8, since most dust particles entrained in the exhaust air will tend to be sucked back into the suction tube 6, and be circulated again through the collection chamber 8.

In practice, there may be a small amount of leakage in the suction system due to imperfections but, apart from this, substantially all of the exhaust air from the collection chamber 8 is returned to the suction head 7 via the exhaust duct 10.

The exit of the exhaust duct 10 is so positioned adjacent the entry to the suction tube 6 as to ensure a useful air flow through the suction head 7, in order to entrain debris swept up from the road or pavement.

There is thus provided a suction sweeper 1 which may be improved over previous suction sweepers, due to the simplicity of construction of the suction chamber 8 with collection bag 9, and the reduced need for significant filtration systems for exhaust air. The suction sweeper 1 is particularly suitable for outdoor use.

The suction sweeper 2 that is shown in Figure 2 is generally similar to that shown in Figure 1. However, in Figure 2 the sweeper is shown in somewhat more detail, and incorporates some modifications. Since like reference numerals denote like or corresponding parts, a general description of those parts already described in Figure 1 will not be repeated. However, the points of difference will now be described.

In Figure 2, the fan 5 is positioned downstream of the collection chamber 8, which is positioned above a substantially rigid, plastics waste bin 9, which serves as the receptacle for collecting debris. The bin 9 is provided with wheels 26 and a handle 27, such that it may be conveniently pushed along a pathway, and is of a type known widely as a "wheelie bin". A cyclone unit 11 is mounted in the collection chamber 8, and, in use, protrudes into the upper area of the wheelie bin 9. The operation of cyclone dust and debris separators is well known, and need not be further explained here.

It will be appreciated that, due to the cyclone action in the collection chamber 8, the debris and dust particles drop mostly into the wheelie bin 9, and only very fine particles remaining in the airstream are then caused to pass through the fan

5 and into the exhaust duct 10.

The exhaust duct 10 terminates at the suction head 7, where gully brushes 12 are mounted. A rotating cross brush 13 is located upstream of the suction head 1, at the downstream end of the exhaust duct 10.

Figure 2 shows the chassis 14 of the sweeper 2, the forward end of the chassis 14 being formed as a first cowl 15, located over the gully brushes 12.

In this respect, the underside of the chassis 14 affords a substantially continuous surface (apart from the passage therethrough of the suction tube 6), to define the cowl 15.

In a similar manner, the gully brushes 12 are mounted on a structure which affords a second cowl 16 in which a suction point 17 for the suction tube

6 is located. All of these details can be seen in more detail in Figure 3.

Referring now in particular to Figure 3, the exhaust duct 10 comprises a rear part 18 and a forward part 19. Air from the fan 5 enters an upper part of the rear part 18, within which there is located a first flap 20 which is pivotable about a substantially horizontal axis 21, and is operative to direct air from the fan 5 either through a forward port 22 or a rear port 23 in the rear part 18 of the exhaust duct 10.

In Figure 3, the first flap 20 is illustrated in a substantially vertical position, in which airflow from the fan 5 is divided between the forward port 22 and the rearward port 23. However, by rotating the first flap 20 about its axis 21, which movement is effected by controls adjacent to a driver when in the seat 3, the airflow from the fan 5 may be directed exclusively either through the forward port 22 or through the rear port 23.

In the forward part 19 of the exhaust duct 10, a second flap 24 is mounted for rotation about a substantially horizontal axis 25, such that it may be moved between a lower position (as seen in Figure 3) and an upper position, by controls situated adjacent a driver when in seat 3.

When the second flap 24 is in its lowermost position as illustrated, air flow entering the forward part 19 is deflected by the flap 24 upwardly through an upper opening 28 in the forward part 19, such that it then encounters the first cowl 15 which directs the airflow generally over and above the gully brushes 12.

When the second flap 24 is in its upper position, the air flow entering the forward part 19 continues in a forward direction and passes through the cross brush 13 to enter the area of the second cowl 16 of the suction head 7.

The above-mentioned additional features of the sweeper 2 that are shown in Figures 2 and 3, both individually and in combination, afford particular advantages of operation. Firstly, in common with the sweeper 1 of Figure 1, the sweeper 2 of Figures 2 and 3 can be used in an environment where it is desired to minimise the emission of duct particles into the atmosphere, due to the useful feature of recirculating air from the fan 5 and collection chamber 8 to the suction head 7.

However, in certain conditions, the recirculation of air to the suction head 7 can lead a loss in performance of the pick up of debris. For example, if one were to attempt to pick up dry leaves on a fine day, then it may be found that the draught of the returning airflow from the exhaust duct 10, in the vicinity of the suction head 7, causes the light, dry leaves to be blown away such that they escape being sucked up by the suction head 7. In such circumstances, the first flap 20 in the rear part 18 of the exhaust duct 10 may be controlled to exhaust all of the air from the fan 5 out of the rear port 23, in the manner of conventional vacuum sweeping devices. Obviously, one loses the advantage of minimising the admission of dust particles by causing them to recirculate. However, suction at the suction head 7 can be improved for the particular job in hand, as and when required. A significant feature of the arrangement is that the direction of the exhaust air is selectable - either out rearwardly as in the conventional sweeper (through filters if desired), or forwardly to the suction head 7 to cause recirculation of the dust particles and therefore cause less pollution.

A particularly advantageous feature is that a mixture of air diverted forwardly for recirculation or rearwardly for emission can be continuously varied via the first flap 20, so that in the case of specific debris requiring less disturbance (e.g. light leaves or dust) the position of the first flap 20 can be gradually adjusted until a satisfactorily pick up is achieved at the suction head 7. In this selected position, the minimum emission of dust via the rear port 23 is achieved.

A yet further degree of adjustment is provided via the second flap 24 in the forward part 19 of the exhaust duct 10. With the second flap 24 in its upper position, all of the air coming from the rear part 18 is directed forwardly through the cross brush 13 and directly to the second cowl 16 in the vicinity of the gully brushes 12 and the suction point 17.

Thus, with all of the air flow from the fan 5 being directed forwardly through the forward port 22 by the first flap 20, and directly ahead by the second flap 24 being in its upper position, maximum recirculation of air is achieved from the exhaust duct 10 and up through the suction point 17 into the suction tube 6. In this condition, the sweeper 2 is suitable not only for outdoor use - for example, in environments such as pedestrian precincts (where low dust emission is highly desirable), but is also particularly suitable for use in enclosed environments, where dust emission may be even more undesirable. For example, the sweeper 2 may be used in stables, where cleaning out is a regular task, but where horses can be susceptible to unduly dusty conditions.

Should it be required to reduce the direct draught of returned air flow at the second cowl 16, (for example, due to very light debris (e.g. dry hay or straw) being blown away form the suction head 7), the second flap 24 may be moved to its lower position as illustrated, in which case the exhaust air is deflected out of the upper port 28 in the forward part 19, to be further directed by the first cowl 15 around the gully brushes 12. Due to the appreciable degree of suction occurring at the suction point 17, such exhaust air tends to be largely drawn again into the suction point 17, but having been diffused into the somewhat greater area defined upwardly via the first cowl 15, re-enters the suction head 7 downwardly from above, rather than forwardly from behind. Thus, debris in the vicinity of the suction head 7 is less likely to be disturbed by this recycling air flow which, when being drawn down from the first cowl 15, may actually assist the entrainment of debris into the suction head 7.

As for the first flap 20, the second 24 may also be infinitely adjustable in position between its uppermost and lowermost extremes, thereby to provide a mix of airflows respectively via the first cowl 15 and directly to the second cowl 16.

When the wheelie bin 9 is full, it is readily detachable from the chassis of the sweeper 2 upon which it is mounted, such that it may be immediately emptied and replaced for re-use, or replaced by another, empty wheelie bin and left for later collection and/or emptying.

In this specification, the verb "comprise" has its normal dictionary meaning, to denote non-exclusive inclusion. That is, use of the word "comprise" (or any of its derivatives) to include one feature or more, does not exclude the possibility of also including further features.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A suction sweeper comprising a suction source, a suction head connected with the suction source, and a collection chamber connected with the suction head, such that, in use of the sweeper, debris in the vicinity of the head is sucked into the head and from there into the collection chamber: wherein air from the collection chamber is exhausted via an exhaust duct to the suction head, to be recirculated through the collection chamber.

2. A suction sweeper according to claim 1, wherein substantially all of the air from the collection chamber is exhausted via the exhaust duct to the suction head, to be recirculated through the collection chamber.

3. A suction sweeper according to claim 1 , further comprising recirculation control means for selectively diverting airflow in the exhaust duct between a recirculation path in which the air is directed to the suction head, to be recirculated through the collection chamber, and a non- recirculation path in which the air is exhausted to atmosphere.

4. A suction sweeper according to claim 3, wherein said recirculation control means is controllable to provide adjustable proportions of air which are directed respectively to said recirculation and non-recirculation paths.

5. A suction sweeper according to any of the preceding claims, further comprising diverting means for selectively diverting airflow in the exhaust duct between a direct path in which the air is directed to the suction head, to be recirculated through the collection chamber, and an indirect path in which the air is directed to the suction head by a route that is less direct than that afforded by said direct path, thereby to reduce potential blow- away of debris in the vicinity of the suction head.

6. A suction sweeper according to claim 5, wherein said diverting means is controllable to provide adjustable proportions of air which are directed respectively to said recirculation and non-recirculation paths.

7. A suction sweeper according to any of the preceding claims, further comprising a cowl in the vicinity of the suction head, to assist airflow into the suction head.

8. A suction sweeper according to any of claims 1 to 6, further comprising first and second cowls in the vicinity of the suction head, to assist airflow into the suction head, the second cowl being closer to the suction head than said first cowl.

9. A suction sweeper according to claims 5 and 7, wherein said first cowl provides at least part of said indirect path and said second cowl provides at least part of said direct path.

10. A suction sweeper according to any of claims 7 to 9, wherein said cowl or one of said cowls is defined by at least part of an assembly for mounting rotatable brushes in the vicinity of the suction head.

1 1. A suction sweeper according to any of claims 7 to 10, wherein said cowl or one of said cowls is defined by at least part of a chassis of the suction sweeper.

12. A suction sweeper according to any of the preceding claims, wherein a cyclone device is mounted at least partially in said collection chamber, to cause particles of debris to fall into a collection receptacle. - IS ¬

I S . A suction sweeper according to any of the preceding claims, further comprising a removable receptacle arranged to collect debris entrained in the air passing through the collection chamber.

14. A suction sweeper according to claim 13, wherein said removable receptacle comprises a bag.

15. A suction sweeper according to claim 13, wherein said removable receptacle comprises a wheeled bin.

16. A suction sweeper according to any of the preceding claims, wherein said sweeper is designed for road or pavement (sidewalk) use.

17. A suction sweeper according to any of the preceding claims, wherein said sweeper is mounted on road wheels.

18. A suction sweeper according to any of the preceding claims, wherein said sweeper is provided with a steering system for said road wheels.

19. A suction sweeper according to any of the preceding claims, wherein said sweeper is provided with a seat for a driver of the sweeper.

20. A suction sweeper according to any of the preceding claims, further comprising one or a plurality of brushes for sweeping debris towards the vicinity of the suction head.

21. A suction sweeper substantially as hereinbefore described with reference to Figure 1, Figure 2 or Figures 2 and 3 of the accompanying diagrammatic dra wings.