WO2010095030A1

WO2010095030A1 - An improved machine for street cleaning and relative method of retrofitting

Info

Publication number: WO2010095030A1
Application number: PCT/IB2010/000347
Authority: WO
Inventors: Guido Giletta; Enzo Giletta
Original assignee: Giletta SpA
Current assignee: Giletta SpA
Priority date: 2009-02-23
Filing date: 2010-02-23
Publication date: 2010-08-26
Anticipated expiration: 2011-08-23
Also published as: IT1394893B1; ES2442916T3; EP2401437B1; ITTO20090127A1; EP2401437A1

Abstract

A machine (1) for cleaning a street surface comprises a vacuum system for sucking in debris, a delivery system to spread a liquid on the street surface, possibly a pressure washing system, a storage volume (12) to retain the debris, a conveyor system to convey the debris from the street surface to said storage volume, and a tank (9) collapsible within the storage volume (12) and connected to the delivery system.

Description

AN IMPROVED MACHINE FOR STREET CLEANING AND RELATIVE METHOD OF RETROFITTING

TECHNICAL FIELD The present invention relates to an improved machine for street cleaning, for example a street sweeping machine and/or a street washing machine. BACKGROUND ART A street cleaning machine generally comprises a storage volume in which the debris is collected and a system for delivering a liquid to dampen the dust and prevent it from being dispersed and/or to wash the surface by means of a high pressure water jet. Street cleaning machines may also comprise a conveyor system for automatically conveying the debris from the street to the storage volume. In machines with a mechanical conveyor system, the cleaning machine comprises a troughed chain conveyor. Alternatively the cleaning machine may be of the vacuum sweeper type, i.e. a vehicle, for example a wheeled vehicle, comprising movable front brushes, a vacuum system for sucking in and conveying the debris moved by the brushes and a humidification system to damp down the dust lifted by the brushes. Moreover, besides sucking in and conveying the debris, a street vacuuming and washing machine also comprises a washing system that delivers a high pressure liquid, for instance water, onto the street surface or onto surfaces that are difficult to reach such as pavements or the areas beneath parked cars .

A preferential requirement for a street - cleaning machine is autonomy of operation, i.e. the length of the duty cycle before using up all the liquid and reaching the maximum limit of stored debris.

A second important requirement for a street cleaning machine is compactness to make it more manoeuvrable, in particular for small machines used for cleaning town and city centres which can have narrow streets and alleys with limited space for manoeuvring.

Compact street cleaning machines are known in the prior art. However, such machines have relatively limited operating autonomy and thus high operating costs as the duty cycle is short .

DISCLOSURE OF INVENTION

The purpose of the present invention is to provide a street cleaning machine that overcomes the drawback described above.

The purpose of the present invention is achieved with a machine according to claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the present invention, it will now be described in detail with reference to the accompanying drawings, in particular: figure 1 is a front perspective view of a street cleaning machine according to the present invention; figure 2 is a rear and partial perspective view of the street cleaning machine of figure 1. BEST MODE FOR CARRYING OUT THE INVENTION

In figure 1, designated as a whole by number 1 is a street cleaning machine, for example a machine for sweeping up debris from a street surface, for instance leaves, paper or gravel. The street sweeper 1 is provided with wheels 2, at least two of which are driving wheels, a driver's cab 3 and a storage volume 4 that is arranged behind the cab 3 and is pivotally connected at a rear end 5 or side so as to be unloaded by means of a linear actuator 6. The street sweeper 1 comprises at least a pair of rotating brushes 7 preferably arranged beneath the cab 3 and in front of the wheels 2, possibly one or more brushes mounted at the front in a cantilevered fashion or on mobile arms, a humidification system controlled automatically by the driver to deliver a liquid, for example water and preferably in the form of a fine spray, and a debris vacuum and storage system.

The brushes 7 are mounted on respective mobile arms and are motor-powered to rotate about a relative axis transversal to the surface to be swept.

The humidification system comprises a plurality of nozzles (not illustrated) at least some of which are arranged in proximity of the brushes 7 to prevent the brushes 7 from lifting too much dust during operation and/or to_ wash the street surface. The humidification system also comprises a pump (not illustrated) and a tank from which the pump draws in the water to send to the nozzles. The street sweeper 1 also comprises an auxiliary collapsible tank 9 releasably connected to the standard and normally rigid tank of the street sweeper to provide a reserve supply of water. In particular, in order to connect the auxiliary tank 9 to the standard tank of the street sweeper the standard humidification system of the street sweeper 1 can be appropriately modified to insert a port to which to connect the auxiliary tank 9.

The vacuum system comprises one or more suction inlets (not illustrated) arranged for example beneath the cab 3 behind the brushes 7, an extraction unit 10 attached for example to a roof R of the box 4 and a duct 11 to connect the inlets to the extraction unit 10 via a storage volume 12 defined within the box 4. Preferably, the extraction unit 10 defines a plurality of suction ports 13 opening towards a rear portion 14 of the roof R or above, an extraction device (not illustrated) fixed to the roof R and connected to the ports 13 and a grid 15 to protect the suction of the extraction device and prevent large pieces of debris, for example leaves, from damaging the moving parts, such as a rotor, of the extraction device.

The -auxiliary tank 9 'is flexible and in particular collapsible. Preferably, it is a bag formed of two sheets preferably of a multi- layer material having an elastomeric matrix and a reinforcing layer comprising a web. The two sheets are joined in a fluid-tight manner along their respective perimeters to form an edge 16 by means of which the auxiliary tank 9 is joined to the walls 17 that laterally delimit the storage volume 12 of the box 4 in proximity to the cab 3.

In particular, the blocking system between the edge 16 and the walls 17 is configured to prevent any debris from escaping, i.e. so that most of the debris sucked in from the street surface is retained between the auxiliary tank 9 and the grid 15. Thus, only a small portion of the debris manages to escape and is drawn due to the force of gravity between the auxiliary tank 9 and a base 18 of the box 4.

Preferably, the auxiliary tank 9 is arranged on a removable structure resting on guideways 19 rigidly connected to the side walls 17. The guideways 19 are continuous and, preferably, inclined towards a tail gate 20 of the box 4. The guideways 19 can be made of an L- shaped section bar joined to the side walls 17. The removable structure comprises a frame 20 slidingly mounted on the guideways 19 and the auxiliary- tank 9 rigidly fixed to the frame 20. Preferably, the edge 16 is joined for example by means of bolts on three sides to the frame 20.

The frame 20 comprises a base 21 on which the auxiliary tank 9 rests at least when the latter is full of liquid, a pair of side walls 22 extending from the base 21 in an opposite direction with respect to the auxiliary tank 9 and two wings 23 that project with respect to the respective side walls 22 and are suitable to cooperate with the respective continuous guideways 19 to support the auxiliary tank 9. For example, the wings 23 come directly into contact with the continuous guideways 19 so that the base 21 is suspended with respect to the base 18 of the box 4.

Possibly, a limited portion of the three sides of the edge 16 is not joined to the frame 20. Preferably, the portions adjacent to the corners of the edge 16 are not joined to the frame 20.

Moreover, the auxiliary tank 9 is provided with an anti- swelling system which acts at least during the emptying of the box 4 to prevent all the liquid from flowing into the rear part of the tank 9 when the box is tilted and preventing the vacuumed debris from slipping out and thus preventing the complete emptying of the box 4. In particular, the anti- swelling system is configured so as to define, at least locally, a limit for the maximum distance in a direction perpendicular to the base 18 between the two sheets of the auxiliary tank 9 so that the upper sheet of the auxiliary tank 9 remains substantially flat and preferably substantially parallel to the base 18.

Preferably, the anti-swelling system envisages the arrangement of tie rods T inside the bag that between them join two anchoring portions arranged on opposite sides with respect to a central plane P of the tank 9 and belonging to the respective sheets of the auxiliary tank 9. Preferably the tie rods T are substantially perpendicular to the base 18 when the auxiliary tank 9 and the frame 20 are mounted on the street sweeper 1, the box 4 is horizontal and the auxiliary tank 9 is full. The length of the tie rods T defines the maximum value of the distance between the two sheets of the auxiliary tank 9. However, the local maximum value of the distance between the two sheets of the auxiliary tank 9 is greater than the length of the tie rods T due to the flexibility of said sheets.

In particular, the distance is defined precisely and equal to the length of the tie rods T between the anchoring portions of the sheets connected respectively to the two ends of the tie rods T. Each sheet, in the area of interposition surrounded by adjacent anchoring portions, is deformed under the action of the water contained in the tank so that the distance between twoareas of interposition is greater than the length of the. tie rods T. In any case, the presence of the tie rods T defines a limit to the deformability of the tank in a direction perpendicular to the base 18.

According to a preferred embodiment of the present invention, the tie rods T are also flexible and can be made of the same material as the sheets of the auxiliary tank 9.

Moreover, the auxiliary tank 9 can be provided with air outlets to simplify filling operations. Preferably, the outlets are connected to a device that prevents liquid from leaking out when the auxiliary tank 9 is compressed by the vacuumed debris. Preferably, said device comprises a piezometric tube 25 having one end that can reach a height that may even exceed the height of the box 4 of the sweeper . In use, the street sweeper 1 starts a duty cycle with the standard tank and the auxiliary tank 9, which may be connected to one another so that the auxiliary tank 9 continuously re-fills the standard tank, both filled to their respective maximum capacities. The auxiliary tank 9 is housed within the storage volume 12 and occupies a pox-tion thereof . When the street sweeper 1 is working with the vacuum system operating, the vacuumed debris is conveyed to the storage volume 12 and deposited on the auxiliary tank 9.

The edge 16 of the auxiliary tank 9 is jfixed to the frame 20 so as to obtain a seal with respect to the debris and prevent this from falling due to the force of gravity underneath the auxiliary tank 9 and thus make cleaning and emptying of the box 4 more difficult.

During the duty cycle, the sprayer system uses the water and the auxiliary tank 9 correspondingly collapses under the action of the vacuumed debris . In this way the storage volume 12 gradually increases until it reaches a maximum value when the auxiliary tank 9 is empty and completely collapsed under the weight of the debris vacuumed by the vacuum system.

The piezometric tube 25 prevents the weight of the debris from acting on the auxiliary tank 9 to make the liquid leak through the outlet.

When the storage volume 12 has reached its maximum capacity, the box 4 is emptied due to the force of gravity by means of the linear actuator 6. The tie rods

T prevent the tank from swelling towards the tail gate

20 when the box is tipped. In this way, the auxiliary tank 9 maintains a substantially flat upper surface facing towards the grid 15 so that the debris slips out of the storage volume 12. If necessary, the auxiliary tank 9 and the frame 20 can be unloaded from the box 4. Thus , according to the present invention, street sweepers already in use can be upgraded or retrofitted with minimum changes to existing and standard systems.

Lastly it is clear that modifications and variations may be made to the street sweeper 1 described and illustrated herein without departing from the scope of the present invention, as set forth in the claims. For example, the street cleaning machine 1 may comprise a pressure washing system comprising a nozzle 30 that can be operated manually by an operator and supplied via a fluid circuit that may be separate from the circuit for the liquid used by the humidification system that interacts with the brushes 7. For example, the fluid circuit comprising the auxiliary tank 9 may also be configured to supply a corrosive and/or acid liquid to the nozzle 30 that would damage the standard tank but can be stored safety and reliably in the auxiliary tank 9. The nozzle 30 is preferably fed by means of a hose 31 supported by a jointed arm 32 borne either by the box or fixed to the frame of the street sweeper 1

Moreover, the auxiliary tank 9 can be fixed and not removable within the box 4. In this case, the edge 16 can be bolted preferably to rectilinear brackets arranged along the walls 17 of the box 4 to retain at least most of the vacuumed debris above the auxiliary- tank 9.

The tank 9 is not necessarily an auxiliary' tank. In the case of a completely re-designed street sweeper, the street sweeper could have a collapsible tank housed within the storage volume 12 as its only tank.

Furthermore, the street sweeper 1 can also comprise a pressure washing system comprising fixed or manually or automatically operated nozzles, for example arranged in front of the brushes 7. Generally speaking, the auxiliary tank 9 can supply several systems in parallel. For example, when the street sweeper also comprises a pressure washing system the latter can be connected in parallel to the humidification system with respect to the auxiliary tank 9. In particular, the humidification and pressure washing systems can comprise separate pumps or share a single pump and can be provided with specific devices to regulate the pressure and the flow rate of the liquid required by the two different systems. Moreover, the tie rods T may be elastic.

Claims

1. A machine (1) for cleaning the street surface comprising a delivery system to spread a liquid on the street surface, .a storage volume (12) configured to receive debris from the street surface and a conveyor system for conveying the debris from the street surface to said storage volume, characterised by comprising a tank (9) collapsible within said storage volume (12) and connected to said delivery system.

2. The machine according to claim 1, characterised in that said tank (9) may be disassembled and removed from said storage volume (12) .

3. The machine according to claim 2, characterised by comprising a frame (20) fixedly connected to said tank (9) and removable from said storage volume (12) .

4. The machine according to any of the preceding claims, characterised in that said storage volume (12) is defined by a box (4) which may be tilted and has a base (18) , and by comprising a device configured so as to limit the maximum swelling of said tank (9) in a direction perpendicular to said base (28) when said box (4) is tilted so as to allow the evacuation of the debris.

5. The machine according to claim 4, characterised in that said device (T) comprises a plurality of tie rods arranged within said tank (9) to connect respective portions of said tank (9) arranged on opposite sides with respect to a central plane (P) of said tank (9) .

6. The machine according to any of the preceding claims, characterised ^'in that said tank (9) comprises at least one outlet to connect said tank (9) to the external environment and a second device (25) connected to said outlet and configured to prevent the liquid from escaping from said tank (9) and being dispersed within said storage volume (12) when the sucked debris compresses said tank (9) .

7. The machine according to claim 6, characterised in that said second device (25) comprises a piezometric tube (25) having an appropriate length.

8. The machine according to any of the preceding claims, characterised in that said tank (9) comprises an edge (16) fixed within said storage volume (12) so as to retain most of the debris sucked above said tank (9) .

9. The machine according to any of the preceding claims, characterised in that said supply system for a liquid is one between a humidification system and/or a pressure washing system.

10. A method of retrofitting a machine according to any of the preceding claims, characterised by comprising the step of mounting said tank (9) in said storage volume (12) and the step of connecting said tank (9) to said washing system.