EP1686078A1

EP1686078A1 - A hopper for charging municipal solid waste in a holding compartment and charging method carried out thereby

Info

Publication number: EP1686078A1
Application number: EP05425039A
Authority: EP
Inventors: Franco Savoldi; Vittorio Ottolina
Original assignee: Omb Brescia SpA
Current assignee: Omb Brescia SpA
Priority date: 2005-01-31
Filing date: 2005-01-31
Publication date: 2006-08-02

Abstract

A hopper for charging municipal solid waste into a container of a motor vehicle (3) comprises a base portion (6) provided with an evacuation opening (5) communicating with an underlying transfer chamber (7), and a shielding wall (18) mounted on the base portion (6). The wall (18) is movable between an emptying position at which it is inclined by an angle adapted to let the waste, disposed on a work surface (19) thereof, fall towards the evacuation opening (5), and a charging position at which the work surface (19) is substantially horizontal to promote emptying of a rubbish skip (15) into the hopper (1).

Description

The present invention relates to a hopper and a process for charging municipal solid waste into a holding compartment.
It is a further object of the invention to provide a device for conveyance of municipal solid waste which is provided with said hopper, and a motor vehicle for waste collection equipped with such a device.
It is known that collection of municipal solid waste from the so-called "rubbish skips" is carried out through appropriate lorries on which suitable transportable containers are installed. The container is provided with a mechanical device that is able to automatically clasp, lift and overturn a rubbish skip, so as to empty the waste contained therein through the charging mouth of a hopper associated with the container, the emptied rubbish skip being then set to the ground again.
The hopper usually has a conveying compartment defined by at least four perimetral walls standing from a base portion and delimiting a charging mouth at the upper part thereof, over which mouth the rubbish skip to be emptied is overturned. Defined in the base portion of the hopper is an evacuation opening communicating with a transfer chamber along which a pusher element shaped like a drawer operates. This pusher element is operated with a reciprocating motion for carrying out compacting of the waste pushing it into the container through an opening formed in one of the perimetral walls separating the holding compartment of the container itself from the conveying compartment of the hopper.
At least one suitably inclined shielding wall is set at the inside of the hopper to efficiently convey the municipal solid waste emptied into the hopper towards the evacuation opening, while at the same time avoiding said waste from directly falling upon the pusher element and/or invading the areas dedicated to the pusher's actuating mechanisms disposed in the vertical projection of the overall dimensions of the hopper charging mouth, in order to reduce the apparatus bulkiness.
The Applicant has however found that in the present state of the art the waste emptied from the rubbish skip tends, at least in a starting step, to store up on the inclined shielding wall, thus hindering an easy emptying of the rubbish skip.
This circumstance imposes an undesirable extension of the waiting times of the vehicle required to terminate a cycle involving emptying and new positioning to the ground of the rubbish skip. In fact, it is necessary to retain the rubbish skip to an overturned position over the hopper at least as far as the action of the pusher element has transferred a certain amount of waste into the container, so that the rubbish skip is cleared of the municipal solid waste accumulated in the upper part of the hopper.
To obviate this drawback without resorting to increases in the hopper sizes that would impair the container capacity, it is presently necessary to increase the lifting height of the rubbish skip when it is overturned, which will bring about problems in terms of energy consumption, time delay in carrying out the steps of lifting and setting the rubbish skip to the ground again, and operating dimensions in height of the apparatus. In this connection it is to be pointed out that the maximum vertical bulkiness of the lorry inclusive of the arm and the rubbish skip in the emptying position must in any case be limited, so as to avoid interferences with elements usually present in the vicinity of the rubbish skip laying areas such as posts, electric wires, signs, placards, buildings, etc.
Should the capacity of the conveying compartment of an hopper be increased by reducing the inclination of the shielding wall relative to the usual values currently included between 30° and 35° with respect to a horizontal plane, the regular flowing of the municipal solid waste towards the evacuation opening would be impaired.
Accordingly, it is an aim of the present invention to overcome the limits and drawbacks of the known art by proposing a hopper enabling the falling height of the waste from the rubbish skip to be increased without said rubbish skip being required to be lifted higher during the emptying step.
It is a further aim of the present invention to conceive a hopper of large capacity enabling the halt time of the vehicle for carrying out the steps of emptying the rubbish skip and positioning it back to the ground to be reduced.
The foregoing and further aims that will become more apparent in the course of the following description are achieved by a hopper for charging municipal solid waste into a holding compartment, comprising the features set out in claims 1 and in the claims depending thereon.
It is a further aim of the invention to provide a device for conveying municipal solid waste integrating the above hopper, as claimed in claim 13, as well as a motor vehicle for collection of municipal solid waste comprising such a device, as claimed in claim 14.
In a new aspect the invention proposes a process for charging municipal solid waste comprising the features set out in claim 15 and in the claims depending thereon.
Further features and advantages will be best understood from the detailed description of a preferred but not exclusive embodiment of a hopper in accordance with the present invention, a conveying device mounted on a motor vehicle for collection of municipal solid waste, and a collecting process carried out in accordance with the present invention.
This description will be set out hereinafter with reference to the accompanying drawings, given by way of non-limiting example, in which:

Fig. 1 is an elevation side view of a portion of a compacting container provided with a hopper in accordance with the invention, with some parts removed for a better view of others;
Fig. 2 is a front view of the portion of the container shown in Fig. 1;
Fig. 3 shows a first detail to an enlarged scale of the hopper seen in Fig. 2; and
Fig. 4 shows a second detail to an enlarged scale of the hopper illustrated in Fig. 1.

With reference to the drawings, a hopper in accordance with the present invention has been generally identified with reference numeral 1 (Fig. 1). Hopper 1 essentially comprises at least four perimetral walls 11, 12, 13 delimiting a conveying compartment 1a having a charging mouth 14 at the upper part thereof and terminating with an evacuation opening 5 at the lower part.
Hopper 1 is associated with a device 2 for conveying municipal solid waste which is usually mounted on a lorry 3 or motor vehicle of other type, known by itself and therefore only partly shown, intended for collection of municipal solid waste from suitable rubbish skips.
The conveying device 2 essentially comprises a container 10 defining a holding compartment 10a, and a press 4 located under the hopper 1 and in communication with the conveying compartment 1a of the latter through the evacuation opening 5 formed in a base portion 6 of the hopper itself. The base portion 6 is disposed in a substantially horizontal plane "X-X".
Press 4 has a transfer chamber 7 within which a pusher 8 slides; said pusher is made like a drawer possibly provided with one or more modules 8a telescopically engaged one after the other and capable of transferring the municipal solid waste coming from opening 5 by drop and pushing it, through an admission port 9, into a holding compartment 10a of the container 10. In fact, pusher 8 is movable in the transfer chamber 7 in parallel to the base portion 6, between a retracted position, at which it is spaced apart from the admission port 9, and a thrust and compression position at which it lies close to the admission port 9.
In the compression position, pusher 8 closes the evacuation opening 5 and occupies chamber 7 in place of the municipal solid waste to be compressed (Fig. 1, chain line). In the retracted position a front portion 8a of drawer 8, substantially perpendicular to the base portion 6, lies substantially flush with an edge 5a of the evacuation opening 5, so as to clear access to the transfer chamber 7 (Fig. 1, solid line).
In more detail as regards the embodiment shown by way of example, in the perimetral walls of hopper 1 interposed between the driver's cab 3a of vehicle 3 and the container 10, it is possible to distinguish a pair of side walls 11 extending vertically from the base portion 6 (Fig. 2). The side walls 11 are connected to each other by a rear perimetral wall 12 separating hopper 1 from the holding compartment 10a of the container 10 and a front perimetral wall 13 located at the front of hopper 1 itself. In a manner known by itself, the rear perimetral wall 12 carrying said port 9 can have at least one portion 12a that is movable away from cab 3a to, in case of need, cause ejection of the waste charged in the holding compartment 10 of the container 10.
The upper edges of the side walls 11, 12, 13 opposite to the base portion 6 delimit the charging mouth 14 onto which an overturned rubbish skip 15, fully represented only in Fig. 2, is brought for emptying of the skip contents into hopper 1. To this aim, an automated grip and emptying device 16 of a type known by itself and therefore not described in detail, is installed on one side of the motor vehicle 3; said device is provided with a pair of mechanical arms only one of which is shown in Fig. 2, that are able to claps the rubbish skip 15 resting on the ground and lift it up while overturning it over the charging mouth 14 of hopper 1. To facilitate falling of the rubbish into the conveying compartment 1a of hopper 1, the side wall 11 located on the vehicle side carrying the grip and emptying device 16 further has a portion 17 sloping towards the outside of hopper 1.
Advantageously, hopper 1 further comprises a shielding wall 18 mounted on the base portion 6 internally of the conveying compartment 1a and having a work surface 19 facing the interior of the conveying compartment itself. This shielding wall 18 is movable between an emptying position, shown in chain line in Fig. 1, at which the work surface 19 is inclined to the horizontal plane X-X by an angle of a value not smaller than a limit value included by way of indication between 30° and 35°, which is adapted to ensure falling by sliding of the waste disposed on the work surface itself, and a charging position, shown in solid line, at which the work surface 19 is inclined to the horizontal plane by an angle of a value smaller than said limit value.
Referring particularly to Fig. 1, the shielding wall 18 is articulated on a substantially horizontal oscillation axis 21 extending adjacent to the rear edge 5a of the evacuation opening 5. To this aim, at least one pin 21a is mounted at the base portion 6 and extends along an end edge 18a of the shielding wall 18 disposed adjacent to said edge 5a of opening 5. The oscillation axis 21 delimits a first region 22 in the base portion 6 that extends as far as the front perimetral wall 15 between the shielding wall 18 and pusher 8, and a second region 23 for communication with the transfer chamber 7, in which the evacuation opening 5 extending from the oscillation axis 21 to the rear perimetral wall 12 is obtained.
The shielding wall 18 is rotated between the first and second operating positions by means of at least one actuator 24, preferably a linear actuator such as a hydraulic or pneumatic cylinder. In the preferred embodiment herein illustrated, hopper 1 comprises a pair of linear actuators 24 working in parallel (Fig. 2).
Actuators 24 each have a first end 24a hinged to the base portion 6, on the first region 22, and a second end 24b hinged on the shielding wall 18. Extension of actuators 24 causes rotation of the shielding wall 18 from the charging position to the emptying position and shortening of said actuators 24 causes rotation of the shielding wall 18 in the opposite way.
Preferably, in the shaking position the work surface 19 of the shielding wall 18 is inclined to the horizontal plane X-X by an angle α₂ not smaller than 30° and preferably at least as large as 35°. In the illustrated example, this angle α₂ is included between 60° and 75°. In the charging position the work surface is on the contrary inclined to the horizontal plane X-X by an angle α₁ smaller than 35°. More particularly, this angle α₁ preferably has the smallest feasible value to keep the shielding wall 18 as low as possible in the conveying compartment 1a of the hopper. To this aim, the value of angle α₁ can be, just as an indication, included between 0° and 20°, and in the example shown it is substantially of 10°.
In any case, at least in the emptying position, the shielding wall 18 together with a plane identified by the edges of opening 5 delimit an obtuse angle α₃ to enable the municipal solid waste to be charged into the press 4, to slide on the work surface 19. In other words, in the emptying position the work surface 19 keeps substantially turned towards the charging mouth 14 of hopper 1.
Advantageously, being defined as "a" the distance between the oscillation axis 21 of the shielding wall 18 and the second end 24b of each actuator 24 and as "b" the distance between the oscillation axis 21 itself and the first end 24b of said actuator 24, "a" is preferably greater than "b". By adopting the geometry herein specified, elongation of actuators 24 to bring the shielding wall 18 from the first to the second emptying position causes a force component counteracting the weight of the municipal solid waste lying on the work surface 19. This advantageously brings about a reduction in the stresses transmitted to pin 21a during the movements of the shielding wall 18.
To prevent insertion of part of the municipal solid waste between the shielding wall 18 and side walls 11, the shielding wall 18 has opposite side edges 25, each of which is disposed adjacent to one of the side walls 11, provided with respective gaskets 26. Each gasket 26 extends along the whole length of the respective edge 25 and lies in sliding contact with the adjacent side wall 11.
Fig. 3 is a cross section view to an enlarged scale of one of gaskets 26. Gasket 26 comprises a flexible element 27, preferably of rubberised cloth, fastened to the edge 25 of the shielding wall 18 by means of suitable anchoring means, such as screws, bolts or preferably rivets. In particular, according to the illustration in Fig. 3, a first end 27a of the flexible element 27 is sandwiched between two plates 28 one of which is rigidly fixed to edge 25, which are held together by a tear rivet 29. A second end 27b of the flexible element 27 takes a curved shape in contact with the side wall 11.
As shown in Figs. 1 and 4, a further gasket 30, preferably of the same material as that of the gaskets adopted on edges 25 of the shielding wall 18, is in addition mounted between the edge 5a of opening 5 and the pin 21a. In more detail, as depicted in Fig. 4, in the same manner as the gaskets located on the side edges of the shielding wall 18, a central region of the flexible element 27 is sandwiched between two plates 28 one of which is rigidly fixed to the edge 5a of opening 5, which are held together by tear rivets 29. Plates 28 are inclined towards opening 5. One end 27a of the flexible element 27 lies in contact with pin 21a while a second end 27b juts out into opening 5, to act against the pusher 8 of press 4 during sliding of said pusher in the transfer chamber 7.
Gasket 30 is adapted to prevent part of the municipal solid waste from entering the space between drawer 8 and the base portion 6 and/or between pin 21a and the base portion 6.
The shielding wall 18 is further advantageously provided with a containment tailpiece 31 extending away from the base portion 6, in the extension of the work surface 19, on the opposite side relative to the oscillation axis 21. As shown in Fig. 1, the tailpiece 31 together with the work surface 19 delimit an angle α₄ preferably included between 90° and 115°, and give the shielding wall 18 a substantially L-shaped configuration or in any case a configuration defining a concavity 32 that, at least in the charging position, faces the charging opening 14 of hopper 1.
The edges of the tailpiece 31 too are adjacent to the side walls 11 and are provided with respective gaskets 27. In the charging position shown in solid line in Fig. 1, the tailpiece 31 lies parallel to the front perimetral wall 13 of hopper 1, bringing an end edge 33 of the shielding wall 18 opposite to the oscillation axis 21 against, or in any case close to, the front perimetral wall itself. During movement to the emptying position, the tailpiece 31 exerts an action adapted to retain the waste in the concavity 32 hindering falling of said waste onto the first region of the base portion 6, under the shielding portion 18.
When the municipal solid waste is being collected, the motor vehicle 3 is stopped at a position alongside the rubbish skip 15, to enable the same to be picked up by the grip device 16 that carries out lifting of same and overturning over the charging mouth 14 of the hopper. During this step, the shielding wall 18 is set in the charging position (Fig. 1, solid line), so that the hopper volume and the falling height of the municipal solid waste in the conveying compartment 1a are maximised. Therefore the municipal solid waste partly falls directly into the transfer chamber 7 through opening 5 and partly settles on the work surface 19.
During emptying of the rubbish skip 15, the actuators 24 can be started, automatically or upon command of the vehicle's driver for example, to cyclically move the shielding wall 18 between the charging position and emptying position, so that oscillations of greater or smaller extension are imposed to said wall thereby allowing the waste to be slightly moved, which will promote discharge of same from the rubbish skip overturned on top of the conveying compartment 1a. Thus the risk of waste heaps being formed that will hinder a regular emptying of the rubbish skip 15 is avoided.
When emptying has been completed, the rubbish skip 15 is brought back to the ground and the motor vehicle 3 can set off again. As soon as the rubbish skip 15 has been removed from the charging mouth 14 of hopper 1, the shielding wall 18 can be shifted to the second operating position, at which the work surface 19 defines a chute ensuring falling of all the municipal solid waste stored on the shielding wall itself.
After all the municipal solid waste in hopper 1 has been transferred to chamber 7 and/or to the holding compartment 10a, the shielding wall 18 is brought back to the first operating position.
The present invention achieves the intended purposes and offers important advantages.
First of all, the hopper in accordance with the present invention allows the falling height of the waste into the conveying compartment 1a of hopper 1 to be increased without increasing the maximum overall dimensions from the ground of the lorry and the rubbish skip raised above the lorry itself. Due to the increased falling height, the heap of waste does never grow up until reaching the rubbish skip, which would prevent full emptying of the latter. The reduction in the maximum overall dimensions in height enables the lorry to operate more easily without being worried about a possible interference with elements usually present in the vicinity of the areas where the rubbish skips are set down.
The hopper in accordance with the present invention, in addition, allows its charging capacity to be increased during emptying so that the waste discharged from the rubbish skip can be received and processed more quickly.
Finally, the hopper in reference enables the waste to be slightly moved during and after the step of emptying the rubbish skip, so that clogging phenomena due to formation of bridge structures by the waste within the conveying compartment 1a are avoided.

Claims

A hopper for charging municipal solid waste into a holding compartment, comprising:
- a base portion (6) provided with an opening (5) for evacuation of the municipal solid waste to said holding compartment (2a), and

- a shielding wall (18) mounted on the base portion (6) and having a work surface (19) turned towards the interior of the hopper;
characterised in that said shielding wall (18) is movable between:
- an emptying position at which the work surface (19) is inclined to a horizontal plane (X-X) by an angle having a value not smaller than a limit value adapted to let the waste disposed on the work surface itself fall towards the evacuation opening (5), and

- a charging position at which the work surface (19) is inclined to said horizontal plane (X-X) by an angle having a smaller value than said limit value.
A hopper as claimed in claim 1, wherein in the emptying position the work surface (19) is inclined by an angle (α₂) larger than 30°, preferably larger than 35°, relative to the horizontal plane (X-X).
A hopper as claimed in claim 1 or 2, wherein in the charging position the work surface (19) is inclined by an angle (α₁) smaller than 35°, preferably included between 0° and 20°, relative to the horizontal plane (X-X).
A hopper as claimed in one or more of the preceding claims, wherein the shielding wall (18) is hinged to the base portion (6) on an oscillation axis (21) extending adjacent to an edge (5a) of the evacuation opening (5), to rotate between the charging position and emptying position.
A hopper as claimed in claim 4, wherein in the charging position the shielding wall (18), on the opposite side from said oscillation axis (21), has an end edge (33) disposed close to a perimetral wall (13) of the hopper itself.
A hopper as claimed in claim 4 or 5, wherein the shielding wall (18) further comprises a containment tailpiece (31) extending in the extension of the work surface (19) on the opposite side from said oscillation axis (21) and away from the base portion (6).
A hopper as claimed in one or more of the preceding claims wherein, at least in the charging position, the shielding wall (18) has a concavity facing a charging mouth (14) of the hopper.
A hopper as claimed in one or more of the preceding claims, comprising at least one actuator (24), preferably a fluid-operated cylinder, for shifting the shielding wall (18) between the charging position and emptying position.
A hopper as claimed in one or more of claims 5 to 8, wherein the shielding wall (18) has opposite side edges (25) each extending between said oscillation axis (21) and said end edge (32), adjacent to a respective side wall (11) of the hopper.
A hopper as claimed in claim 9, further comprising gaskets (26), each mounted on the respective side edge (25) and acting in sliding contact with the respective side wall (11).
A hopper as claimed in one or more of the preceding claims 4 to 11, further comprising at least one gasket (30) mounted between the edge (5a) of the evacuation opening (5) and the shielding wall, at said oscillation axis (21).
A device for conveying municipal solid waste, comprising a container (10) defining a holding compartment (10a), a hopper (1) communicating with said container (10) through a transfer chamber (7) disposed below an evacuation opening (6) of the hopper (1), and a pusher (8) movable in the transfer chamber (7) to convey the municipal solid waste from the evacuation opening (6) into the container (10), characterised in that said hopper (1) is made in accordance with one or more of the preceding claims.
A motor vehicle for collection of municipal solid waste, comprising a device (16) for gripping and emptying rubbish skips (15) and a conveying device (2) according to the preceding claim.
A process for charging municipal solid waste into a holding compartment, comprising the steps of:
- setting a hopper (1) having a base portion (6) provided with an opening (5) for evacuation of the municipal solid waste towards said holding compartment (10a), and a shielding wall (18) mounted on the base portion (6) and having a work surface (19) turned towards the interior of the hopper (1);

- positioning the shielding wall (18) to a charging position, at which the work surface (19) is inclined to a horizontal plane (X-X) by an angle having a smaller value than a limit value adapted to let the municipal solid waste, disposed on the work surface itself, fall towards the evacuation opening (5);

- discharging the municipal solid waste into the hopper (1) ;

- shifting the shielding wall (18) to an emptying position, at which the work surface (19) is inclined to the horizontal plane (X-X) by an angle of a value not smaller than said limit value;

- transferring the municipal solid waste to the holding compartment (10a) through the evacuation opening (6); and

- bringing the shielding wall (18) back to the charging position.
A process as claimed in claim 15, wherein the step of shifting the shielding wall (18) is carried out through rotation of said shielding wall (18) about an oscillation axis (21) extending adjacent to an edge (5a) of the evacuation opening (5).
A process as claimed in claim 14 or 15, wherein the step of positioning the shielding wall (18) to the emptying position is carried out through inclination of said shielding wall (18) relative to the horizontal plane (X-X) by an angle (α₂) greater than 30°, preferably greater than 35°.
A process as claimed in one or more of the preceding claims 14 to 16, wherein the step of positioning the shielding wall (18) to the charging position is carried out through inclination of said shielding wall (18) relative to the horizontal plane (X-X) by an angle (α₁) smaller than 35°, preferably included between 0° and 25°.
A process as claimed in one or more of the preceding claims 14 to 17, further comprising the step of cyclically moving the shielding wall (18) between the charging position and emptying position during said discharging step.