GB2355972A

GB2355972A - Refuse lorry with means for compacting and distributing load in order to optimise axle weighting.

Info

Publication number: GB2355972A
Application number: GB9919358A
Authority: GB
Inventors: Christopher John Blakemore
Original assignee: SPECIALIST VEHICLES Ltd
Current assignee: SPECIALIST VEHICLES Ltd
Priority date: 1999-08-17
Filing date: 1999-08-17
Publication date: 2001-05-09
Also published as: GB9919358D0

Abstract

The present invention relates to a refuse vehicle (10) (figure 1) having front and rear axles (14, 16), a storage body (18) for refuse, and compacting means for compacting refuse deposited in the storage body (18), the compacting means being operable to control the position of the refuse in a fore and aft direction in the storage body (18) and/or control the compaction of the refuse so as to distribute the refuse in a desired manner. Advantageously the vehicle (10) is provided with means (38, 40) for sensing axle load and control means (44, 46) to control the position and/or compaction of the refuse in the storage body (18) to distribute the sensed load over the axles (14, 16) in a desired manner.

Description

2355972 A REFUSE VEHICLE AND A METHOD OF FILLING A REFUSE VEHICLE The

invention relates to a refuse vehicle and a method of filling a refuse vehicle.

When filling a refuse vehicle, the gross vehicle weight (that is the combined weight of the refuse vehicle and its refuse) and front and rear axle weights of a refuse vehicle must stay within certain limits to meet legal requirements. However, in known refuse vehicles, rear axles can overload long before the maximum allowable gross vehicle weight (GVW) is utilised, whilst the maximum load threshold for the front axle is not 10 exploited.

It is an airn of the invention to provide a refuse vehicle that allows optimum loading thereof and an improved method of filling a refuse vehicle.

According to a first aspect of the invention there is provided a refuse vehicle comprising front and rear axles, a storage body.for the refuse and compacting means for compacting refuse deposited in the storage body, the compacting means being operable to control the position of the refuse in a fore and aft direction in the storage body and/or control the compaction of the refuse so as to distribute the refuse in a 20 desired manner.

In one embodiment, the refuse vehicle is provided with means for sensing axle load and control means to control the position and/or compaction of the refuse in the storage body to distribute the sensed load over the axles in a desired manner.

2 In such a case, general movement of the refuse in a forward direction enables the load on the front axle to be increased and the load on the rear axle to be decreased. When the control means causes deposited refuse to be moved in the aft direction, the load on the rear axle will be increased and the load on the front axle decreased. In that way, the refuse can be loaded in such a way as to optimise axle loading to that which is desirable.

The compaction of the refuse may increase as a result of the aforesaid aft movement.

The compacting means preferably comprises a compactor and a member against which the refuse is compacted, the member preferably being movable. The control means may control the member or compactor and preferably controls both the member and the compactor. The member is preferably movable in the fore-and-aft direction. When it is moved in the aft direction to optimise axle loading, the member may be arranged to 15 increase the compaction of the refuse.

Preferably, the compactor can pack the refuse in the body at a plurality of pressures to vary the compaction of the refuse.

The compactor is preferably positioned at a first position on the body such as a rear end and the said member is preferably located between the said first position and a second position on the body remote from the first position such as a front end.

Preferably, fluid-operable means controlled by the control means is used to operate the 25 member and/or the compactor.

3 Preferably, the member operates at various pressures to vary the degree of compaction.

If desired, the control means may receive a signal from the load sensing means to enable the control means to control the position or compaction of the refuse. The control means preferably includes a processing unit which may be electronic. The control means preferably includes a control unit which controls the compacting means in response to a signal from the processing unit.

The said member preferably takes the form of an ejector used for ejecting compacted refuse from the body when the body has been filled.

The means for sensing axle load may comprise sensor means on the axle or on another suitable part of the vehicle sensitive to loading resulting from the deposited refuse.

The sensor means may sense axle/chassis suspension deflection for example by means of a strain gauge arrangement or it may sense pressure in a pressurised suspension for the vehicle, the pressure in the suspension varying with load resulting from the depositing of refuse in the storage body.

In another arrangement, the sensor means may sense loading and/or deflection at areas where a suspension for the vehicle is attached between a part of the vehicle and each of the axles.

4 In a further arrangement, the sensor means may be mounted on the storage body and is sensitive to load resulting from the depositing of refuse in the body, the sensor being calibrated to provide an indication of corresponding axle loading. The sensor means may be a load cell.

The refuse vehicle may comprise a further axle either between the said front and rear axles or aft of the rear axle. The further axle preferably bears load only when the weight on the front and/or rear axle exceeds a certain level. The ftirther axle may include or be associated with means for sensing load thereon.

In a second embodiment of the invention, the refuse vehicle comprises a position sensor that senses a position of the member within the body. The position sensor may be a proximity switch or the like.

Preferably, the refuse vehicle comprises a control means such as an analogue controller that receives a signal from the position sensor.

The control means preferably controls the compacting means to compact the refuse at a plurality of compaction pressures.

According to a second aspect of the invention there is provided a method of loading a refuse vehicle comprising front and rear axles, a storage body and compacting means for compacting refuse deposited in the storage body, the method comprising controlling the compacting means to control the position and/or compaction of the refuse in a fore and aft direction in the storage body so as to distribute the refuse in the body in a desired manner.

In a first embodiment, the method includes sensing load on front and rear axles and 5 controlling the position and/or compaction of the refuse in the storage body to distribute the sensed load over the axles in a desired manner.

The method may include moving the refuse in the forward direction to enable loading on the front axle to be increased and the loading on the rear axle to be decreased. The method may include moving refuse in the aft direction whereupon, the loading on the rear axle will be increased and the loading on the front axle decreased.

The method may include transmitting a signal from the load sensing means to a control means to enable the control means to control the position or compaction of the refuse.

The control means may include a control unit and, preferably, a processing unit. Where the control and processing units are provided, the method may include using the control unit to control the compacting means in response to a signal from the processing unit.

Once the allowable gross weight for the said vehicle is approached, the method may include preventing further movement of refuse in the aft direction and continuing the loading of refuse into the body until the allowable gross vehicle weight is substantially reached. In that way, the vehicle can be loaded in a way which not only optimises the axle loading but which also enables optimum loading of the body up to the allowable 6 gross weight of the vehicle. Therefore, a vehicle in accordance with the invention offers significant legal loading advantages over those proposed hitherto.

In a second embodiment, where the step of providing compacting means comprises providing a compactor and a member against which the refuse is compacted, the method includes loading the body with refuse at a first compaction pressure which causes the member to move away from the compactor and maintaining a load on one of the axles such as the front axle at or above a minimum, sensing the position of the member within the body and, when the member reaches a given position within the body, causing the member to move towards the compactor to increase compaction of the refuse.

Preferably, loading the body with refuse continues at a pressure higher than the first compaction pressure until the body is substantially full.

15- Preferably, the step of sensing the position of the member comprises providing a position sensor such as a proximity switch which causes the member to move towards the compactor. Preferably, the method includes controlling the extent to which movement of the said member increases such compaction by means of an axle load sensing means on, for example, a front axle of the refuse vehicle. Preferably, once the axle load sensing means reaches a desired minimum level for example 20% of the gross vehicle weight the position sensor controls the movement of the member towards the compactor causing such movement towards the compactor to cease. The method may include subsequently causing the compactor to compact further refuse in the storage body thereby causing the member to move away from the compactor again. In 7 that case, the position sensor may be overridden or deactivated so that the member continues to move away from the compactor.

Preferably, the pressure applied to the refuse by the compacting means can be varied, for example iteratively, between a first pressure corresponding to the ideal compaction density necessary to fill the body and reach the GVW and a second pressure corresponding to the ideal compaction density necessary to fill the body and maintain a minimum load on the front axle as a percentage of the GVW, the pressure varying steps preferably continuing until the storage body is full.

In that way, the loading on an axle, such as the front axle, can be maintained at or above a desired level, for example, 20% of the gross vehicle weight whilst filling of the storage body and reaching of the maximum allowable GVW is achieved.

A refuse vehicle and a method of filling a refuse vehicle will now be described with reference to the accompanying drawings, in which, Fig. I is a schematic longitudinal cross section of a refuse vehicle in accordance with the invention, Fig. 2 shows the refuse vehicle of Fig. 1 in an empty state, Fig. 3 shows the refuse vehicle of Fig. I partly loaded with refuse, Fig. 4 shows the refuse vehicle of Fig. 1, approaching overload at its rear axle, 8 Figs. 5 and 6 show the refuse vehicle of Fig. I during further stages of loading, Fig. 7 shows the refuse vehicle of Fig. 1, the body having an optimised payload, 5 Fig 8 is a longitudinal cross section of a further refuse vehicle in accordance with the invention, and Fig 9 is a graph to show the method of loading the further refuse vehicle.

Referring to Fig 1, a refuse vehicle 10 comprises a chassis 12 supported by front and rear axles 14, 16 respectively. Each axle 14, 16 carries wheels 17. The chassis 12 supports a storage body 18, the storage body having a hopper 20 at its rear end 2 1. The body 18 contains an ejection barrier 22 between its front end 23 and its rear end 2 1. The hopper 20 includes a compactor 24. The barrier 22 and the compactor 24 are controlled by first and second fluid-operable rams 26 and 28, respectively.

The barrier 22 may be wedge shaped with front and rear faces 30, 32 respectively. The barrier 22 is movable by the first fluid-operable ram 26 along the body with working clearance.

The pressure which is applied to the second fluid operable rams 28 can be varied, for example from one value to another, e.g. from 190 bar to 210 bar or can be varied infinitely between desired values.

9 The front and rear axles 14, 16 have respective load sensors such as strain gauges 38, 40 positioned thereon. The load sensor 38, 40 are calibrated so that they sense the change in axle load as a result of refuse deposited into the storage body. Then, the fixed weight of the rest of the refuse vehicle is added to give the GVW.

A further axle 42 can be provided between the front and rear axles 14, 16. The further axle 42 can move between a normal retracted position and an extended position as shown in Fig I by solid and broken lines respectively. The further axle 42 has a further load sensor 43 positioned thereon.

Each of the load sensors 38, 40, 43 is connected to an electronic processor 44 and a logic based controller 46. The controller 46 controls the fluid operable rams, 26, 28.

With the farther axle 42 raised, loads sensed by the load sensors 38, 40 form inputs a 1.5 to the processor 44, which in turn sends an input b to the controller 46. The controller 46 can then send an output c to each of the fluid operable rams 26, 28. Depending on the outputs c of the logic based controller 46, the barrier 22 is able to move towards the rear end 21 or front end 23 of the body 18. Also, the rear compactor 24 can vary the pressure it exerts on the refuse 48 by virtue of outputs c to the rams 28.

The operation of the refuse vehicle 10 is shown schematically in Figs. 2 to 7.

Referring to Fig 2, the barrier 22 is initially positioned towards the rear end 21 of the body, the face 32 being adjacent the compactor 24. Initially, only the front and rear axles 14, 16 are in contact with the ground.

Referring to Fig 3, the body 18 is loaded with refuse 48 and the barrier 22 moves towards the front end 23 under pressure from the compacted refuse. The axle weights are monitored by the sensors 38, 40 and the GVW is determined by adding the sensed axle weights together. In Fig 3, the weights are assumed to be well within defined limits.

As loading of refuse continues, the rear axle weight approaches its legal maximum. As that occurs, an output c from the logic based controller 46 (again see Fig 1) causes the barrier 22 to move towards the front end 23 of the body 18 as shown in Fig 4. In that way, a space shown schematically by 50 is formed between the face 32 of the barrier 22 and the refuse 48 and the centre of gravity of the barrier 22 is moved forwards away from the rear axle 16. Continued operation of the compactor 24 moves the refuse forwards whereby the load on the rear axle 16 decreases and the load on the front axle 14 increases. In that way, the GVW and axle weights are maintained within defined limits. With continued filling, the refuse 48 eventually comes back into contact with the barrier 22 and the compactor 24 packs the refuse 48 under pressure once more against the barrier 22.

As the weight on the front axle approaches its legal maximum, the refuse density can be increased by moving the barrier 22 towards the rear end 21 of the body 18 shown in Fig 5 by the broken line arrow. That will, in effect, move the centre of gravity of the refuse 48 and the barrier 22 rearwards to relieve the front axle of some of its load.

11 As the front axle 14 weight reduces to, say, 20 % of the GVW in any condition, the barrier 22 will be moved forward as shown by the solid line arrow, enabling the weight of subsequently loaded refuse and the barrier centre of gravity to be moved towards the front axle 14 once more. Compaction pressure in the rams 28 may be increased to aid 5 the forward movement of refuse 48.

If the GVW exceeds a certain level, the further axle 42 can be moved from its retracted position into its extended position shown in broken lines in Fig 1. Conversely, if the GVW falls below the level, the further axle can be returned to its retracted position. In the extended position, wheels 17 on the further axle 42 contact the ground so as to redistribute the GVW over three axles. When the further axle 42 is in the extended position the fin-ther sensor 43 comes into operation and the GVW is determined by adding the three axle weights.

It will be appreciated that the density of the refuse 48 can be varied and the weight of the refuse can be distributed as desired. Loading of refuse is continued as shown in Fig 6, until the body approaches its fully loaded state as shown in Fig 7. The barrier 22 is then kept stationary with the base 30 adjacent the front end 23 whilst the rear compactor 24 continues to load at normal or increased pressure to compress the refuse 48 until the body 18 is filled, provided that the maximum allowable GVW is not exceeded. When the vehicle is at the desired fill level the refuse 48 can be ejected by moving the barrier 22 rearwards.

12 In another embodiment of the invention, load can be sensed by measurement of axle/chassis suspension deflection (not shown). In such a case, the deflection can be sensed by a strain gauge arrangement.

In still another embodiment, the sensor means senses pressure in a pressutised suspension (not shown) for the vehicle 10, the pressure in the suspension varying with load resulting from the depositing of refuse 48 in the storage body 18.

In a further embodiment, the sensor means senses loading and/or deflection at areas 10 where a suspension (not shown) for the vehicle 10 is attached between a part of the vehicle and each of the axles 14, 16, 42.

In a still further embodiment, the sensor means 38, 40, 43 is mounted on the storage body 18 and is sensitive to load resulting from the depositing of refuse 48 in the body, 1.5 the sensor being calibrated to provide an indication of corresponding axle loading. The sensor means may be a load cell.

A further refuse vehicle 52 in accordance with the invention is shown in Fig 8, where parts corresponding to those in Fig I carTy the same reference numerals and will not be described again in detail. In Fig 8, the refuse vehicle 52 has an analogue control system (not shown) comprising an analogue controller 54 and a position sensor such as a proximity switch indicated at B. The proximity switch at B senses a linear position of the barrier 22 along the length of the body 18.

13 A first ideal compaction density for the refuse 48, for example 350 kg/cubic metre is calculated to maintain the legal minimum percentage loading, say 20% of the maximum allowable GVW on the front axle 14 and to fill the body 18 completely. A second ideal compaction density for the refuse 48, for example 480 kg/cubic metre, is calculated to achieve the maximum allowable GVW of the refuse vehicle 52 and to fill the body 18 of the refuse vehicle completely. The first ideal compaction density is always lower than the second ideal compaction density and will normally not let the maximum allowable GVW be achieved.

Initial loading of the body 18 at a compaction pressure corresponding to the second ideal compaction density is inadvisable as the refuse 48 will cause a cantilever effect that reduces the load on the front axle below the legal minimum percentage of the GVW.

Instead, prior to loading, the analogue controller 54 controls the rams 28 so that the compactor 24 packs at a pressure which will provide the first ideal compaction density throughout the refuse 48 and controls the rams 26 to provide a relief pressure in the rams 26 corresponding to the first ideal compaction density. In use, the body 18 is loaded with refuse 48 at its rear end 21 and the barrier 22 moves from point A (empty) to, say, point B. The rams 26 allow the barrier 22 to move forwards under the compaction during continued loading whilst maintaining the first ideal compaction density. When point B is reached and loading on the front axle 14 continues to increase beyond the legal minimum percentage loading, a signal is sent from the proximity switch at B causing the analogue controller 54 to initialise movement of the barrier 22 towards the rear end 21 to, say, position C. At the same time the pressure in the rams 14 28 is increased to provide a compaction pressure corresponding to the second ideal compaction density. Loading then proceeds using the compaction pressure corresponding to the second ideal compaction density until the body 18 is completely filled with refuse 48. When the refuse 48 is ejected by the barrier 22, the barrier 22 will remain at the rear end 21 of the body 18 and the lower barrier ejection/ dump pressure is preferably reinstated so that the reftise vehicle 52 is ready to recommence the loading cycle.

Referring to Fig 9, where the X axis measures the distance of the barrier 22 from its position adjacent the compactor 24 (i.e. when the refuse vehicle 52 is empty) and the Y axis measures the load on the front axle 14 as a percentage of the GVW, the effects of the method of loading described above are illustrated for a typical refuse vehicle 52.

The upper curve shows the front axle 14 under the action of loading at the first ideal compaction density from virtually the start of the loading cycle at A to when the body 18 is approximately 2/3 full as indicated at B. By operating the above pressure and compaction variances the load on the front axle can be maintained above the legal minimum percentage, i.e. the 20% axis. The straight line from B to C illustrates back packing with the barrier 22 to achieve a refuse density approximate to that of the second ideal compaction density. The GVW at B and C is identical. Compaction of refuse 48 continues at the pressure corresponding to the second ideal compaction density until the body 18 is full. In that case, the signal from the proximity switch at B is overridden or deactivated so that the barrier 22 is allowed to move past the switch at B. Following ejection of the refuse 48 the lower setting will be reinstated for the next loading cycle.

Different refuse vehicles 10, 52 will require differing combinations of pressure settings, compaction and density.

The above loading operations may be iterative between the compaction pressure corresponding to the first ideal compaction density and the compaction pressure corresponding to the second ideal compaction density until the body 18 is full.

Claims

iG Claims

I A refuse vehicle comprising front and rear axles, a storage body for the refuse and compacting means for compacting refuse deposited in the storage body, the compacting means being operable to control the position of the refuse in a fore and aft direction in the storage body and/or control the compaction of the refuse so as to distribute the refuse in a desired manner.
2 A refuse vehicle according to claim 1 in which the refuse vehicle is provided with means for sensing axle load and control means to control the position and/or compaction of the refuse in the storage body to distribute the sensed load over the axles in a desired manner.
3 A refuse vehicle according to claim I or 2 in which, in use, the compaction of the refuse increases as a result of the aforesaid aft movement.
4 A refuse vehicle according to claim 1, 2 or 3 in which the compacting means comprises a compactor and a member against which the refuse is compacted.
5 A refuse vehicle according to claim 4 in which the member is movable.
6 A refuse vehicle according to claim 5 in which the member is movable in the fore-and-aft direction.
7 A refuse vehicle according to claim 6 in which the member is arranged to increase the compaction of the refuse against the compactor when it is moved in the aft direction to optimise axle loading.
8 A refuse vehicle according to any of claims 4 to 7 in which the control means 30 controls the member or the member and the compactor.

IT
9 A refuse vehicle according to any of claims 4 to 8 in which'the compactor can pack the refuse in the body at a plurality of pressures to vary the compaction of the refuse.
10 A refuse vehicle according to any of claims 4 to 9 in which the compactor is positioned at a first position on the body such as a rear end.
11 A refuse vehicle according to claim 10 in which the member is located between the first position and a second position on the body remote from the first position such 10 as a front end.
12 A reftise vehicle according to any of claims 4 to 11 in which fluidoperable means controlled by the control means is used to operate the member and/or the compactor.
13 A refuse vehicle according to any of claims 4 to 12 in which the member operates at various pressures to vary the degree of compaction.
14 A refuse vehicle according to any of claims 4 to 13 in which the member takes the form of an ejector used for ejecting compacted refuse from the body when the body has 20 been filled.
15 A reftise vehi-cle according to any preceding claim in which the control means receives a signal from the load sensing means to enable the control means to control the position or compaction of the refuse. 25
16 A refuse vehicle according to any preceding claim in which the control means includes a processing unit such as an electronic processing unit.
17 A refuse vehicle according to claim 16 in which the control means includes a 30 control unit which controls the compacting means in response to a signal from the processing unit.
IS 18 A refuse vehicle according to any preceding claim in which the means for sensing axle load comprises a sensor means on the axle or on another suitable part of the vehicle sensitive to loading resulting from the deposited refuse.
19 A refuse vehicle according to claim 18 in which sensor means senses axle/chassis suspension deflection by means of a strain gauge arrangement or by sensing pressure in a pressurised suspension for the vehicle, the pressure in the suspension varying with load resulting from the depositing of refuse in the storage body. 10
20 A refuse vehicle according to claim 18 in which the sensor means senses loading and/or deflection at areas where a suspension for the vehicle is attached between a part of the vehicle and each of the axles.
21 A refuse vehicle according to claim 18 in which the sensor means is mounted on 15 the storage body and is sensitive to load resulting from the depositing of refuse in the body, the sensor means being calibrated to provide an indication of corresponding axle loading.
22. A refuse vehicle according to claim 18 in which the sensor means is a load cell. 20
23 A reffise vehicle according to any preceding claim in which the reffise vehicle comprises a further axle either between the front and rear axles or aft of the rear axle.
24 A refuse vehicle according to claim 23, in which the further axle bears load only
25 when the weight on the front and/or rear axle exceeds a certain level. 25. A reffise vehicle according to claim 23, in which the further axle includes or is associated with means for sensing load thereon. 30
26 A reffise vehicle according to claim 4 in which the refuse vehicle comprises a position sensor such as a proximity sensor or the like which senses the position of the member within the body.

Ici
27 A refuse vehicle according to claim 24 comprising control means such as an analogue controller which receives a signal from the position sensor, the control means being arranged to control the compacting means to compact the refuse at a plurality of compaction pressures.
28 A method of loading a refuse vehicle comprising front and rear axles, a storage body and compacting means for compacting refuse deposited in the storage body, the method comprising controlling the compacting means to control the position and/or compaction of the refuse in a fore and aft direction in the storage body so as to distribute the refuse in the body in a desired manner. 29 A method according to claim 28 including sensing load on front and rear axles and controlling the position and/or compaction of the refuse in the storage body to distribute the sensed load over the axles in a desired manner. 15 30 A method according to claim 29 including moving the refiise in the forward direction to enable loading on the front axle to be increased and the loading on the rear axle to be decreased or moving refuse in the aft direction whereupon, the loading on the rear axle will be increased and the loading on the front axle decreased. 20 31 A method according to claim 29 or 30 wherein once the allowable gross weight for the vehicle is approached, the method includes preventing- further movement of refiise in the aft direction and continuing the loading of refuse into the body until the allowable gross vehicle weight is substantially reached.

25 32 A method according to claim 28 including providing a compactor and a member against which the refiise is compacted, the method includes loading the body with refuse at a first compaction pressure which causes the member to move away from the compactor and maintaining a load on one of the axles such as the front axle at or above 30 a minimum, sensing the position of the member within the body and, when the member reaches a given position within the body, causing the member to move towards the compactor to increase compaction of the refuse.

2L 33 A method according to claim 32 in which the step of sensing the position of the member comprises providing a position sensor such as a proximity switch which causes the member to move towards the compactor. 5 34 A refuse vehicle substantially as hereinbefore described with reference to or as shown in figures I to 8 of the accomapnying drawings.

A method of loading a refuse vehicle substantially as hereinbefore described with reference to or as shown in the accompanying drawings.