GB2224261A - Tipping containers into refuse vehicles - Google Patents

Abstract

A hoist for a refuse collection vehicle includes a carrier (18) for a refuse container. The carrier is connected with a support (19) rigid with a body (14) of the vehicle by a pair of links (21, 22). One of these links is an extensible ram (22) which is extended to tip the carrier, after the container has been raised from the ground, by means of a further ram (23). A gravity-operated latch (27) is arranged to contact the rim (17) of the container as it is being tilted into the emptying position. <IMAGE>

Description

Title:"Hoist and method of clomping a container to a carrier" Description of the Invention From one aspect, the present invention relates to a method of clamping a container to a carrier of a hoist. The invention also relates to hoists suitable for lifting containers and tipping the containers to discharge contents therefrom. The invention has been devised primarily for use in the collection of refuse by means of a vehicle having a hoist for lifting and tipping bins or other refuse containers from the ground and replacing the containers on the ground after emptying the contents of the container into a load space defined by a body of the vehicle.

In our published application GB 2,1 28,578A, there is described a hoist mounted on a refuse collection vehicle. The hoist comprises a carrier connected by a parallelogram linkage with a support. The support is mounted on a body of the vehicle for pivoting relative thereto about a horizontal axis.

The carrier includes an upwardly projecting row of teeth for engagement beneath the lip of a refuse container having an outwardly projecting lip. A clamp is mounted on and fixed with respect to the support. As the configuration of the linkage is changed to raise the row of teeth and a bin suspended thereon, the lip of the bin is moved into close proximity with the clamp so that the clamp either holds the lip of the bin on the teeth or prevents significant movement of the lip away from the teeth. After the container has been raised to the clamp, the support is pivoted relative to the body of the vehicle to tip the carrier and the container so that the contents of the container fall into the body of the vehicle. The clamp prevents the container falling from the carrier.

The hoist described in GB 2,1 28,578A is satisfactory in a case where all refuse to be loaded into the vehicle body is in lipped containers which can be picked up by the hoist. The hoist is unsatisfactory in cases where refuse is to be loaded into the vehicle body by hond or from containers which cannot be picked up by the hoist. An example of such a container is a skip.

A refuse skip is typically such that it can contain many times the volume of refuse which can be accommodated in a lipped container suitable for being lifted by the hoist disclosed in the aforesaid published specification.

For discharging the contents of a skip into the body of a vehicle, it is usual to provide the vehicle with a pair of bearing lugs at a rear end of the vehicle for co-operation with complementary formations on the skip, whilst the skip is standing on the ground. The vehicle is also provided with pivoted arms which can be raised above the body of the vehicle and chains for connecting the arms with the skip at positions between the ends of the skip. The chains are drawn upwardly to tip the skip about the bearing lugs on the vehicle body.

This arrangement cannot be used in a vehicle provided with the hoist disclosed in GB 2,128,578A, because the clamp and other parts of the hoist obstruct access to the vehicle body, even when the carrier is in a lowered position.

According to a first aspect of the invention, there is provided a method of clamping to a carrier of a hoist a container having an outwardly projecting lip wherein a clamp is mounted on the carrier for limited movement relative thereto, the carrier is raised into engagement with the underside of the container lip, the carrier is raised further to lift the container, the carrier is tipped relative to the clamp so that the lip approaches and engages the clamp, the clamp tipping less than the carrier or not tipping until the lip engages the clamp, and wherein the clamp then tips with the carrier and the container.

By mounting the clamp on the carrier, the clomp is lowered with the carrier when the carrier is moved to a lower position so, that the clamp is less of an obstruction than is the clamp disclosed in CB 2,128,578A.

According to a second aspect of the invention, there is provided a hoist suitable for mounting on a vehicle for raising containers from the ground, clamping containers by a method in accordance with claim I and tipping the containers to discharge the contents thereof into a body of the vehicle, the hoist comprising a carrier having formations for engaging beneath a lip of the container to lift the container from the ground and a clamp for holding the lip of the container on or adjacent to said formations, wherein the clamp is mounted on the carrier for movement relative thereto under the action of gravity between clamping and releasing positions.

Arranging the clamp to be moved by gravity between its clamping and releasing positions enables the structure of the hoist to be simplified, since it is unnecessary to provide hydraulic rams or other devices for moving the clamp.

According to a third aspect of the invention, there is provided a hoist suitable for mounting on a vehicle for raising containers from the ground and tipping the containers to discharge contents thereof into a body of the vehicle, the hoist comprising a support for mounting on the body of the vehicle, a carrier for the container and a linkage connecting the carrier with the support, the linkage being a parallelogram linkage of which the support is a first member, the carrier is an opposite member and of which a third member is a fluid actuated ram.

By changing the length of the ram, the carrier can be tipped relative to the support. Accordingly, in a hoist in accordance with the third aspect of the invention, it is unnecessary to provide for tipping of the support relative to the vehicle.

An example of a vehicle used in a method in accordance with the invention and which emhodies the second and third aspects of the invention will now be described, with reference to the accompanying drawings, wherein: FIGURE 1 shows diagrammatically a perspective view of the vehicle from one side and the rear, together with a container; FIGURE 2 shows certain parts of the vehicle, as viewed from one side of the vehicle; and FIGURE 3 shows on an enlarged scale certain of the parts shown in Figure 2.

The vehicle illustrated in Figure 1 comprises a chassis 10 mounted on steerable front wheels 11 and driven rear wheels 12. On the chassis, there is mounted a cab 13 for operators of the vehicle and a hollow body 14 for containing a load. At the rear end of the vehicle, the body defines a rearwardly facing loading opening which extends downwardly from the top of the body to a level somewhat above the bottom of the body and which extends across almost the entire width of the body. The body may include a pivoted tailgate which defines the loading opening, extends forwardly from that opening and includes a hopper and a packing mechanism for moving refuse into a forward part of the body. The tailgate and packing mechanism may be of known construction and will not be -described further nor illustrated in the drawings.

There is mounted on the body 14 at the rear of the vehicle a hoist 15 for lifting a container 16 from the ground and tipping the contents of the container into the body 14. For clarity of illustration of the hoist, the hoist is shown in Figure 1 as having a height which is somewhat increased relative to the overall height of the vehicle, as compared with the hoist which would be fitted to the vehicle in practice.

The paticolar example of container illustrated in the drawing at 16 is of square or other rectangular shape, as viewed in plan, and has an outwardly projecting lip 17 at the upper margin of each of its walls. Between the lip and each wall, there is defined a downwardly facing channel. The lip may be additionally connected with walls of the container by gussets. The container may be provided with a pivoted lid and with a pair of wheels. Such containers are well known.

The hoist 15 includes a carrier 18 for corrying the container 16, a support 19 and a parallelogram linkage 20 connecting the carrier with the support. By a parallelogram linkage, we mean herein a linkage comprising four members each pivotally connected with another two of the members for movement relative thereto about mutually parallel axes, each pair of adjacent pivot axes being spaced apart by a distance substantially equal to the spacing between the opposite pair of pivot axes so that the attitude of each member remains substantially constant with respect to an opposite member of the linkage, as the configuration of the linkage is changed. In the hoist 15, one member of the linkage is constituted by the support 19, an opposite member of the linkage is constituted by the carrier 18, a third member of the linkage is constituted by a bar 21 and the fourth member of the linkage is constituted by an extensible member 22. Preferably the extensible member is a fluid-actuated ram.

The linkage 20 lies at one side of the vehicle body 14. The support 19 is rigidly secured to the vehicle body at the rear end thereof and other members of the linkage protrude rearwardly from the body. The hoist further comprises a corresponding linkage (not shown) at the opposite side of the vehicle body. The carrier 18 extends across the entire width of the vehicle body.

A lift ram 23 is provided for pivoting the bar 21 relative to the vehicle body 14 to change the configuration of the linkage 20. One end portion of the lift ram is pivotally connected with the bar 21 between the ends thereof and the lift ram is pivotally connected adjacent to its opposite end with the vehicle body at a position above the linkage 20. It will be appreciated that alternative means may be provided for pivoting the bar 21 relative to the body.

If the configuration of the linkage 20 is varied by contraction or expansion of the lift ram 23 whilst the ram 22 remains in a contracted condition, then.the angular relation of the carrier 18 to the support 19 and the vehicle body 14 is substantially unchanged throughout pivoting movement of the bar 21. It will be understood that there may be some angular movement of the carrier relative to the vehicle body. However, such angular movement of the carrier as does occur whilst the ram 22 remains in a contracted condition is insufficient to tip significantly a container 16 on the carrier. Significant tipping of the container is such as might cause refuse to be tipped from the container prematurely.

The carrier 18 has a row of upwardly projecting teeth 24 suitably arranged for engagement with the lip 17 at the underside thereof in the channel defined between the lip and the wall of the container 16. Any gussets present in the channel and downwardly extending flanges on the lip provided on adjacent walls of the container can lie between adjacent teeth 24 so that they do not prevent the lip seating firmly on the teeth. The carrier further comprises a rest 25 for engaging the container at a level between the top and the bottom of the container. The rest lies at least approximately directly beneath the teeth 24, when the carrier is in the upright attitude illustrated in Figure 2, in which the carrier can be engaged with a bin standing on the ground.

The pivot connection between the bar 21 and the carrier 18 preferably includes a rectilinear shaft 26 which extends from the linkage 20 to the corresponding linkage at the other side of the vehicle body 14 and which is clamped or otherwise secured to the bar 21 adjacent to one end thereof. The carrier includes a sleeve which is a sliding fit on the shaft 26 which lies between the bar 21 and the corresponding bar of the other linkage. The sleeve is arranged to turn freely on the shaft and turning of the sleeve relative to the shaft is controlled by the ram 22.

There is provided on the carrier 18 a clamp 27 for releasably holding the lip 17 of the container in engagement with or immediafely adjacent to the teeth 24 of the carrier so that the container cannot become inadvertently separated from the carrier. The particular clamp illustrated is mounted on the carrier for pivoting relative thereto through a limited angle about an axis 28 which is parallel to the axis of the shaft 26. The axis 28 lies forwardly of the teeth 24 and, when the carrier is in the attitude shown in Figure 2, is at a level somewhat below the tops of the teeth. The pivots defining the axis 28 are connected with the sleeve of the carrier by brackets 29. There may be a plurality of these brockets spaced apart along the sleeve.

The clamp 27 includes an abutment portion which extends without interruption along the entire length of the row of teeth 24. The clamp can pivot relative to the carrier from the releasing position illustrated by a full line in Figure 2, in which the abutment portion is spaced considerably from the teeth 24, to a clamping position shown by a full line in Figure 3, in which the abutment portion 30 overlies the teeth 24 to engage or almost engage the lip 17, when on the teeth 24. The clamp is freely pivotoble under the action of gravity relative to the carrier between these extreme positions.

The carrier includes a tail 31 extending from the axis 28 in a direction approximately opposite to that in which the abutment portion 30 is spaced from that axis. The tail carries a weight 32 which lies at a considerable distance below the axis 28 and, when the parts are in the position shown by full lines in Figure 2, lies somewhat forwardly of the axis 28. The arrangement is such that the centre of gravity of the clamp lies below the axis 28, when the parts are in the position shown by full lines in Figure 2.

Whilst the lift ram 23 is fully extended and the ram 22 is maintained in a contracted condition, the carrier 18 occupies the lowered position illustrated by full lines in Figure 2. In this position, the carrier and the clamp are spaced downwardly from the lower margin of the opening defined by the body 14 through which refuse can be loaded into the body. Furthermore, the carrier projects only a short distance rearwardly from the body 14. In this position, the carrier and clamp do not obstruct access to the vehicle body by a skip. Provided suitable devices for co-operation with the skip are provided on the body 14, a skip can be emptied into the body. Furthermore, refuse can be loaded by hand into the body.

If, with the carrier in the lowered position represented in Figure 2, the container 16 is placed on the ground just to the rear of the carrier and the lift ram 23 is then contracted, the teeth 24 of the carrier will be raised into the downwardly facing channel at the underside of the lip 17 of the container.

It will be noted that, as the lift ram 23 is contracted, the carrier will move upwardly and slightly rearwardly relative to the vehicle body, thereby ensuring that the teeth 24 move into the channel at the underside of the lip 17 and do not pass the lip. Typically, the teeth engage the lip 17 before the axis of the shaft 26 rises to the level of the pivotal connection between the bar 21 and the support 19.

Continued contraction of the lift ram 23 raises the container 16 from the ground to the position represented by a broken line in Figure 2. It will be noted that the container is maintained in a substantially upright attitude and that the clamp 27 remains in the releasing position whilst the bin and carrier are in the upright attitude.

Once contraction of the lift ram 23 has been completed, the ram 22 is extended to turn the carrier 18 about the shaft 26. Because the centre of gravity of the clamp 27 lies below the axis 28, the clamp does not participate in initial turning of the carrier or participates in only part of the initial turning of the carrier. Accordingly, the carrier tips the container 16 so that the lip 17 approaches the abutment portion 30 of the clamp. The clamp is then in the clamping position with respect to the carrier and container. The clamp then participates in further tipping of the container about the shaft 26.

Tipping of the clamp may be coused by the action of the lip 17 on the abutment portion 30 of the clamp or by co-operation between parts of the carrier and the clamp which limit relative pivoting, once the clamp has assumed the clamping position. Continued extension of the ram 22 causes the container to be partly inverted so that contents fall from the container into the load space of the body 14. The ram 22 is then contracted to return the container to an upright attitude and the lift ram 23 is extended to return the container to the ground.

During return of the container 16 to the upright attitude, the clamp 27 does not participate fully in tipping of the carrier 18. Once the centre of gravity of the clamp lies approximately directly beneath the axis 28, the clamp ceases to tip with the carrier and the lip 17 moves away from the abutment portion 30 of the clamp so that, once the container has reached the ground, continued downward movement of the carrier will withdraw the teeth 24 from the channel beneath the lip 17.

There is further provided on the carrier retaining means for retaining the clamp 27 in its clamping position whilst the container 16 is inverted over the load space. In the example illustrated, the retainer 33 is mounted on the braket 29 for pivoting thereto about an axis which is parallel to the axis 28.

The retainer 33 is free to pivot through a limited range relative to the carrier 18 under the action of gravity. As shown in broken lines in Figure 3, when the carrier is an upright attitude, the retainer pivot is adjacent to an upper end of the retainer.

At a position remote from its pivot, the retainer 33 is formed with a recess 34 for teceiving a projection 35 provided on the clamp 37. The arrangement is such that the projection 35 can be received in the recess 34 only when the clamp is in its clamping position. When the projection is seated in the recess, the retainer 33 prevents movement of the projection towards the pivot axis of the retainer and thereby prevents pivoting of the clamp from its clamping position towards its releasing position. Whilst a container carried on the carrier 18 is inverted over the load space of the vehicle body 14, the retainer 33 is biased by gravity into the position illustrated in Figure 3, in which the projection 35 occupies the recess 34.

During tipping of the carrier and container from the upright attitude, the retainer does not participate in tipping of the carrier until the clamp has assumed its clamping position. When in its clamping position, the clamp tips with the carrier 18 and the projection 35 moves into the recess 34.

Thereafter, the projection 35 acts on the retainer in the recess 34 to cause the retainer to tip with the carrier against the biasing of gravity. During return of the carrier and container to the upright attitude, the retainer 33 ceases to participate in tipping of the carrier first so that the projection 35 leaves the recess 34. The clamp 27 ceases to porticipate in tipping of the carrier, once the projection 35 has left its recess.

It will be noted that the hoist does not include rams, springs or other means dedicated to biasing of the retainer 33 and of the clamp 37. Pivoting of these components results solely from the action of gravity and the action of the ram 22.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (18)

CLAI MS:

1. A method of clamping to a carrier of a hoist a container having an outwardly projecting lip wherein a clamp is mounted on the carrier for limited movement relative thereto, the carrier is raised into engagement with the underside of the lip, the carrier is raised further to lift the container, the carrier is tipped relative to the clamp so that the lip approaches and engages the clamp, the clamp tipping less than the carrier or not tipping until the lip engages the clamp, and wherein the clamp then tips with the carrier and the container.

2. A method according to Claim I, wherein until the lip engages the clamp, gravity alone restrains tipping of the clamp with the carrier.

3. A method according to Claim I or Claim 2 wherein, during tipping of the clamp with the container and carrier, the clamp tips relative to a retainer until the clamp engages the retainer and wherein the retainer then prevents tipping the clamp relative to the carrier in a direction away from the lip.

4. A hoist suitable for mounting on a vehicle for raising containers from the ground, for clamping the containers by a method according to Claim I and tipping the containers to discharge contents thereof into a body of the vehicle, the hoist comprising a carrier having formations for engaging beneath a lip of a container to lift the container from the ground and a clamp for holding the lip of the container on or adjacent to said formations, wherein the clamp is mounted on the carrier for movement relative thereto under the action of gravity between clamping and releasing positions.

5. A hoist according to Claim 4 further comprising a retainer for retaining the clamp in the clamping position, wherein the retainer also is mounted on the carrier for movement relative thereto under the action of gravity.

6. A hoist according to Claim 4 or Claim S further comprising a support for the carrier and links connecting the carrier with the support for limited displacement of the clamp and the carrier together relative to the support.

7. A hoist according to any one of Claims 4 to 6 wherein the clamp is mounted for pivoting relative to the carrier.

8. A hoist according to Claim 7, as appendant to Claim 5, wherein the retainer is mounted for pivoting relative to the carrier.

9. A hoist according to Claim 6 wherein the carrier, the support and said links together constitute a parallelogram linkage.

10. A hoist according to Claim 9 wherein one of said links is an extensible and contractable link.

II. A hoist suitable for mounting on a vehicle for raising containers from the ground and tipping the containers to discharge contents thereof into a body of the vehicle, the hoist comprising a support for mounting on the body of the vehicle, a carrier for the container and links connecting the carrier with the support, wherein the support, the carrier and said links together constitute a parallelogram linkage of which one link is extensible and contractable.

12. A hoist according to Claim II wherein the other of said links is an inextensible link.

13. A vehicle having a hoist according to Claim II or Claim 12 wherein the hoist comprises a fluid actuated ram, a lower end of said ram is pivotally connected to the other of said links and an upper end of the ram is pivotally connected with a body of the vehicle.

14. A method discharging the contents of a container into the body of a vehicle wherein the vehicle is provided with a hoist including a carrier and a support connected by links with the carrier, the carrier is raised relative to the support, the container is clamped to the carrier and wherein the carrier, the container and the clamp are tipped together relative to the support by extension of one of said links.

15. A method according to Claim 14 wherein the container is clamped to the carrier by a method according to Claim I.

16. A hoist substantially as herein described with reference to the accompanying drawing.

17. A method of lifting, clamping and tipping a lipped container substantially as herein described with reference to the accompanying drawing.

18. Any novel feature or novel combination of features disclosed herein or in the accompanying drawing.