GB2465381A

GB2465381A - Rotary brush

Info

Publication number: GB2465381A
Application number: GB0820904A
Authority: GB
Inventors: Alan Riach; Peter Munnoch
Original assignee: Applied Sweepers Ltd
Current assignee: Applied Sweepers Ltd
Priority date: 2008-11-14
Filing date: 2008-11-14
Publication date: 2010-05-19
Also published as: GB0820904D0

Abstract

A rotary brush for a sweeping machine, the brush having a plurality of first bristles 26 and a plurality of second bristles 28, the first bristles being stiffer than the second bristles. The first bristles may be thicker or made from a different material to the second material and the second bristles may be coated by PTFE such that the first and second materials have different frictional coifficients. The bristles may be arranged in circumferential rows 25, 27 proximate the outer edge of a carrier plate 20 or may be arranged on a cylinder brush 30 in first and second helical rows 38, 40. The brush is for use on a battery powered sweeping machine and is intended to reduce overall power consumption.

Description

Rotary Brush The present invention relates to rotary brushes, in particular rotary brushes for sweeping machines.

Sweeping machines are known which comprise a four wheeled vehicle with a cab at its front end, behind which is located a refuse hopper capable of taking up to approximately a tonne of swept up rubbish or other material. Such machines have steerable front and/or rear wheels controlled from the cab. They further include a pair of contra rotating brushes, extending in front of the cab and visible to the operator within the cab. The brushes are able to sweep a width varying from about 1 to 2.5 metres, the width of which can be controllable from the cab. Machines are normally provided with a suction arrangement to pick up rubbish swept to a central location between the contra rotating brushes. GB23 82056 shows an example of such a machine. In this case, each contra rotating brush rotates about a substantially vertical axis.

Sweeping machines are also known to include a cylindrical brush which rotates about a substantially horizontal axis. The cylindrical brush is orientated generally laterally with respect to the vehicle and sweeps rubbish and other material into a hopper. An example of such a machine is shown in W02006/12 1783.

In both cases the bristles of the brushes engage the ground surface in order to sweep rubbish and in doing so friction is created between the bristles and the ground. The amount of energy required to drive the brushes can be a significant proportion of the total energy available from the primary power source of the vehicle.

There is therefore a need to reduce the overall power consumption of the vehicle in order to save energy and minimise the carbon footprint of the vehicle.

Thus, according to the present invention there is provided a rotary brush for a sweeping machine, the brush having a plurality of first bristles and a plurality of second bristles, the first bristles being stiffer than the second bristles.

Advantageously the first set of bristles, being stiffer, will primarily act to loosen debris from the ground. The set of second bristles, being less than stiff, will primarily act to transport the loosened material towards the hopper. Since relatively stiff brushes are not required for transporting material, the set of second bristles can effectively transport the material without requiring as much energy to do so.

A further aspect of the present invention provides a rotary brush for a sweeping machine having a plurality of first bristles and a plurality of second bristles, the 0 second bristles having a surface with a lower coefficient of friction than a surface of the first bristles.

Advantageously the set of first bristles can act to loosen debris and the set of second bristles can act to transport the debris to the hopper. Since the set of second bristles 1 5 has a lower coefficient of friction, then they require less energy to be driven.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a sweeping machine including a rotary brush according to the present invention, Figure 2 shows a part cross section view of the rotary brushes of figure 1, and Figure 3 shows a rotary brush in the form of a cylinder brush according to the present invention.

With reference to figure 1 there is shown a sweeping machine having front wheels 3 and rear wheels 1. A cabin 5 is mounted at the front of the machine having a side door 7 to allow access and egress of an operator. A steering column 8 includes a steering wheel to allow the vehicle to be manoeuvred. A pair of contra rotating brushes 9 are positioned in front of the cabin and sweep debris to a central location C. At the central location a suction pipe (not shown) sucks up the debris and deposits it in hopper 10. Each rotary brush 9 rotates about a substantially vertical axis A. Figure 2 shows a part cross section view of rotary brush 9 of figure 1. Rotary brush includes a bristle carrier plate 20 which is plate like and circular in plan view. At the top of the carrier plate are mounted attachment features 22 which allow the rotary brush 9 to be attached to and detached from a drive means located at the ends of the arms 6 of the sweeping machine. Proximate the peripheral edge 24 of the carrier plate is provided a first circumferential row 25 of first bristles 26. A second circumferential row 27 of second bristles 28 is also provided proximate the peripheral edge 24 but radially inside the first circumferential row 25.

In a first embodiment, according to the present invention the first bristles 26 are stiffer than the second bristles 28. Jn this manner, the first bristles 26 tend to loosen debris and the second bristles 28 tend to transport the debris to the central location. In this way, the energy required to drive the brush is less than the energy required if the second bristles were as stiff as the first bristles.

In an alternative embodiment according to the present invention, the first bristles 26 may be less stiff than the second bristles 28. In this way, the energy required to drive the brush is less than if the first bristles were as stiff as the second bristles.

In a further embodiment according to the present invention the first row 25 may include a series of relatively stiff bristles and a series of relatively less stiff bristles.

The second row may include a series of relatively stiff bristles and a series of relatively less stiff bristles. In this manner the relatively stiff bristles in the first and second rows can act to loosen debris whereas the relatively less stiff bristles in the first and second rows can act to transport the debris to the central location C. In a further embodiment according to the present invention the first bristles 26 may have a surface of each of the bristles having a higher coefficient of friction than a surface of each bristle of the second bristles 28. The first bristles 26 may then act to loosen debris and the second bristles may then act to transport the debris to a central location C. This arrangement reduces the power consumption of the brush when compared to a brush having bristles with a surface coefficient of friction which is relatively high.

In an alternative configuration the first bristles 26 may have a coefficient of friction and is higher than the coefficient of friction of the second bristles 28.

In a further embodiment according to the present invention the first row 25 may include certain bristles having a relatively high coefficient of the friction and certain bristles having a relatively low coefficient of friction and the second row 27 may include certain bristles having a relatively high coefficient of friction and certain bristles having a relatively low coefficient of friction.

With reference to figure 3 there is shown a rotary brush 30 in the form of a cylinder brush. Brush 30 has an elongate core 32 in this case in the form of a cylinder. A set of first bristles 34 project generally radially away from said core and are arranged as a first helix 38 on the core. A set of second bristles 36 project generally radially away from the core and are arranged on a second helix 40. The helical arrangement of the first set of bristles 34 is axially spaced from the helical arrangement of the set of second bristles 36.

In a first embodiment according to the present invention the first bristles 34 are relatively stiff compared to the second bristles 36.

In a second embodiment according to the present invention the first helix 38 include certain bristles which are relatively stiff and certain bristles which are relatively less stiff. The second helix 40 include certain bristles which are relatively stiff and certain bristles which are relatively less stiff.

In a further embodiment according to the present invention the first bristles 34 have a surface having a lower coefficient of friction than surface of the set of second bristles 36.

In a further embodiment the first helix 38 include certain bristles having a lower coefficient of friction than other bristles within the first helix bristles. Certain bristles within the second helix 40 may have a surface having a lower coefficient of friction than other bristles within the second helix 40.

Known sweeping machines having a cabin may have a primary power source in the form of an internal combustion engine. The internal combustion engine may be diesel powered, petrol (gasoline) powered, or gas powered. A further embodiment of the present invention uses a battery powered sweeping machine including one or more rotary brushes as defined in the claims.

Advantageously, using rotary brushes according to the present invention will use less energy than conventional rotary brushes and hence a battery powered sweeping machine will be able to run for longer without having to recharge or replace the batteries. This is advantageous because replacing batteries can typically only be done at the base depot from which the sweeping machine operates. Alternatively, when the batteries are recharged the time taken to recharge can be several hours. As such, a battery powered sweeping machine using rotary brushes according to the present invention will be able to leave the depot from which it operates, complete a full shift of sweeping, and return to the depot with less likelihood of the batteries becoming depleted.

For ease of explanation, relatively stiff bristles are described above as acting to loosen debris and relatively less stiff bristles have been described as acting to transport the debris. Of course relatively stiff bristles will also act to transport debris and relatively less stiff bristles will act to loosen debris. However, relatively stiff bristles are better at loosening the debris than relatively less stiff bristles. Relatively less stiff bristles require less energy to transport debris than do relatively stiff bristles.

Similarly, bristles having a relatively higher coefficient of friction will also act to transport debris and bristles having a relatively lower coefficient of friction will also act to loosen debris. However, bristles with a relatively high coefficient of friction are better able to loosen debris than bristles with a relatively low coefficient of friction.

Bristles with a relatively low coefficient of friction require less energy to transport material than do bristles of a relatively high coefficient of friction.

Claims

Claims 1. A rotary brush for a sweeping machine, the brush having a plurality of first bristles and a plurality of second bristles, the first bristles being stiffer than the second bristles.
2. A rotary brush as defined in claim I in which the first bristles are thicker than the second bristles. I0
3. A rotary brush as defined in claim 1 or 2 in which the first bristles are made from a first material and the second bristles are made from a second material.
4. A rotary brush for a sweeping machine having a plurality of first bristles and a plurality of second bristles, the second bristles having a surface with a lower coefficient of friction than a surface of the first bristles.
5. A rotary brush as defined in claim 4 in which the first bristles are made from a first material and the second bristles are made from a second material.
6. A rotary brush as defined in claim 5 in which the second material is PTFE.
7. A rotary brush as defined in any preceding claim in which the second bristles are coated with a lower friction material such as PTFE.
8. A rotary brush as defined in any preceding claim including a bristle carrier plate, the first bristles and second bristles being arranged proximate an outer edge of the bristle carrier plate.
9. A rotary brush as defined in claim 8 in which the rotary brush includes a first circumferential row of first bristles and a second circumferential row of second bristles.
10. A rotary brush as defined in claim 9 in which the first circumferential row has a large diameter than the second circumferential row.
11. A rotary brush as defined in claim 9 in which the first circumferential row has a smaller diameter than the second circumferential row.
12. A rotary brush as defined in any one of claims I to 7 in which the rotary brush is a cylinder brush and includes an elongate core and the first bristles and second bristles project generally radially away from said core.
13. A rotary brush as defined in claim 12 in which the plurality of first bristles are arranged in a first helix along the elongate core and the plurality of second bristles are arranged in a second helix along the elongate core and the first helix is axially spaced from the second helix.
14. A battery powered sweeping machine including one or more brushes as defined in any preceding claim.