GB2167036A

GB2167036A - Refuse loading apparatus

Info

Publication number: GB2167036A
Application number: GB08526506A
Authority: GB
Inventors: Francis H Pittenger; Larry D Horning
Original assignee: Peabody International Corp
Current assignee: Peabody International Corp
Priority date: 1984-11-15
Filing date: 1985-10-28
Publication date: 1986-05-21
Also published as: JPS61166401A; AU4901585A; GB8526506D0

Abstract

A tailgate for a rear loading refuse vehicle has spaced vertical side walls and a hopper bottom (18) defining a rear refuse inlet opening (20) and a forward refuse outlet opening (22). A packing blade (26) and fallback shield (28) are moved by hydraulic cylinders (38, 54) and linkages (30, 48) without the use of internal slides to move the refuse from the hopper bottom through the outlet opening, into the body of the vehicle. Links (30, 48) on both ends of the fallback shield permit translation of the fallback shield between optimum locations to maximise compaction by the packing blade. <IMAGE>

Description

SPECIFICATION Refuse loading apparatus This invention relates to refuse collection vehicles, and more particularly to the mechanism for actuation of a packing blade and a fallback shield in a tailgate housing for a rear loading refuse vehicle.

The tailgate housing is generally constructed with vertical side walls that are spaced apart the width of the refuse vehicle body to provide a maximum loading area. A hopper bottom is provided to contain the refuse as it is collected and against which a packing blade can travel to move and compact the refuse from a rear inlet opening to a forward outlet opening and thence into the body of the vehicle. The packing blade extends across the width of the vehicle for complete utility.

The loading mechanism of most present day tailgate housings includes a fallback shield which moves to some extent with the packing blade to prevent the back flow of refuse which has been and which is being moved forwards into the vehicle body. The shield must of necessity extend the width of the packing blade upwards from the top thereof.

The patent art is replete with tailgate refuse handling mechanisms incorporating the elements enumerated above. U.S. Patent No. 3, 615,028 to Appleman et al and U.S. Patent No. 3,615,029 to Anderson are examples of such tailgate mechanisms employing upwardly and forwardly inclined linear guide tracks in the vertical side walls, in which a transversely extending heavy carrier plate slides. The packing blade is pivotally connected along its upper edge to the lower edge of the carrier plate. Hydraulic cylinders are mounted on the carrier plate with their piston rods connected to the packing blade to rotate it in relation to the hopper bottom.The carrier plate is moved up and down in the guide tracks by cylinders mounted on the outside of the vehicle side walls, the bases of the cylinders being located at the Ibwer rear end of the guide track and their piston rods being connected through the side walls to the carrier plate so that, as the cylinders are extended, the packing blade is moved upwards and forwards against the hopper to move the refuse through the hopper from the inlet as the plate is swung, and out through the outlet as the carrier plate and attached packing blade are raised. The fallback shield is rigidly mounted on the carrier plate, and thus has restricted linear motion, as shown in Figures 4 and 5 of that Anderson Patent Specification.Various improvements have been made to the structures, for exampie, as shown in U.S. patent Nos. 3,746,192 and 3,177,917 both to Herpich et al, to relocate the sweep cylinder from the carrier plate to a position between the upper rear portion of the tailgate housing and the packer blade, thus eliminating the massive carrier plate and attendant force problems; the fallback shield extending across the tailgate has its edges extending into linear guide tracks, thus again restricting its motion to a linear one. Similarly, as shown in U.S.Patent Specification 4,029,224 of Herpich et al, where the packing cylinders were relocated from an exterior lower position to an interior position extending downwards from an upper forward position, thereby accomplishing another substantial reduction in loading forces and providing a greater clearance for a given capacity, the fallback shield remains attached to the slide blocks at each side, and this continues to restrict motion to a straight line.

When internal slides are eliminated and the required movements of the packing blade are accomplished by the use of hydraulic cylinders and linkages, without regard to the desired movement of the fallback shield, the resulting motion of the shield is restricted to a circular arc.

It is, therefore, a principal aim of this invention to provide a packing blade and fallback shield operating mechanism for the tailgate of a rear loading refuse vehicle that does not limit the motion of the failback shield to a straight line or a circular arc.

It is another aim of this invention to retain the forced distribution advantages of the aforementioned improvement patents, but to eliminate the internal slides which have been the source of complaints because they tend to trap grit that causes wear, and they present maintenance problems such as the tendency for foreign material to be trapped in the slides, and the requirement for greasing the slide elements.

It is still another aim of this invention to eliminate the use of internal slides and to accomplish improved movement and effectiveness of the packing blade as well as to accomplish an optimum translation of the fallback shield which is not limited to movement in a circular arc or along a single line.

The aims of this invention are accomplished in an improved operating mechanism and method of operation for a tailgate of a rear loading refuse vehicle. The fallback shield is articulated at both its ends by moving pivotal connections. The tailgate has wall means defining its overall housing which includes spaced vertical side walls and a hopper bottom which together define a rear refuse inlet opening and a forward refuse outlet opening.

The implements used for loading or moving and compacting the refuse through the tailgate from the rear inlet to the forward outlet are the packing blade and a fallbgack shield. The fallback shield is mounted above the packing blade and is caused to move with it in a manner to enhance compaction by the formation of an optimum transport and compaction path forward of the moving packing blade. The packing blade is generally rectangular in configuration, and extends across the entire width of the tailgate. The packaging blade is supported at each side of its upper end by one of a pair of radial packing blade links attached by a moving pivotal connection. The other ends of the packing blade links are pivotally connected to the tailgate wall adjacent to the upper end of the inlet opening.A pair of hydraulic sweep cylinders are pivotally connected on each side of the packing blade at a point between the upper and lower hori zontal edges of the blade. The other ends of the sweep cylinders are connected to the wall at the upper end of the inlet opening subjacent the pivotal connections of the packing blade links to the wall. Commonly, these connections to the wall would be by means of a pair of brackets, one at each side of the tailgate, supporting the upper, forward packing blade link pivotal connections and the lower, rearward sweep cylinder pivotal connections.The base ends of the sweep cylinders are preferably pivoted to these brackets and the piston rod ends of the sweep cylinders are connected to the packing blade The articulated fallback shield is located above the packing blade and extends across the width of the tailgate, being pivotally connected at its lower end to the packing blade preferably on a common axis with the pivotal connection of the packing blade links to the packing blade. The other end of the articulated fallback shield is supported at each side by radial shield links which are pivotally connected at each side to the upper end of the shield.

The other ends of the shield links are pivotally connected to the wall adjacent the upper rear portion of the tailgate. A pair of hydraulic packing cylinders are each pivotally connected at their upper ends to the side wall at the upper forward end of the tailgate. The other ends of the cylinders are pivotally connected to the upper end of the packing blade, preferably along the same common axis as the pivotal connection of the packing blade to the packing blade links and the fallback shield.

Preferably, the bases of the cylinders are connected at the upper forward end of the tailgate and the piston rod ends are connected to this common pivot.

The method of operation consists of four distinct sequential steps involving extension or retraction of one of the sweep or packing cylinders in turn.

The complexity of the hydraulic circuit is minimised by not requiring simultaneous operation of these cylinders. The pivotal connection of the packing blade links to the packing blade is along a first movable axis, the other end of the packing blade links being pivotally connected to the wall along a second fixed axis. The sweep cylinder piston rods are connected along a third movable axis at each side of the packing blade at a point between the upper and lower horizontal edges of the blade. The base ends of the sweep cylinders are pivotally connected to the wall along a fourth fixed axis which is subjacent the second fixed axis. The articulated fallback shield is pivotally connected at its lower end along the common first movable axis to the packing blade and the packing blade links.The pair of radial shield links are pivotally connected to the upper end of the shield along a fifth movable axis and the other ends of the shield links are pivotally connected to the wall along a sixth fixed axis. The piston rod ends of the packing cylinders are pivotally connected at their lower ends to the common first movable axis interconnecting them to the packing blade, the lower end of the shield and the radial. packing blade links. The base ends of the packing cylinders are connected to the wall along a seventh fixed axis. Starting with the packing blade in its transport position, closing off the forward refuse outlet opening into the truck body, the hopper is loaded with refuse through the rear refuse opening until it reaches its capacity. The loading and compaction mechanism is then set into motion to perform the following four step method of operation.

1. The sweep cylinders are retracted, swinging the packing blade about the first movable axis away from the refuse outlet opening. The fallback shield remains stationary in a substantially upright position; 2. The packing cylinders are extended. This produces swinging of the upper end of the packing blade downwards and rearwards to a substantially horizontal position with its lower edge above the rear portion of the hopper bottom while the fallback shield is translated to a lower rearward position to form a transport and compaction path. This extension of the packing cylinder causes the first movable axis to swing about the second fixed axis.

The third movable axis is swung about the fourth fixed axis and the fifth movable axis is swung about the sixth axis. The packing cylinder itself, as it extends, freely swing through small angle about the seventh fixed axis.

3. The sweep cylinders are extended. This causes the lower end of the packing blade to swing downwards and forwards so as to move the refuse in a compaction and transport path against the hopper bottom and fallback shield. The third movable axis is swung about the first movable axis as the first movable axis and the fifth movable axis remain stationary, holding the fallback shield in a stationary position.

4. The packing cylinders are retracted. This causes the packing blade to be swept upwards and forwards towards the refuse outlet opening, moving the refuse through the transport and compaction path while the faliback shield moves upwards and forwards. The third movable axis is swung about the fourth fixed axis while the first movable axis swings about the second fixed axis and the fifth movable axis swings about the sixth fixed axis. As the packing cylinders retract they swing about the seventh fixed axis.

The preferred embodiments of the invention are illustrated in the drawings in which: Figure 1 is a side elevation view partially in vertical cross-section showing the tailgate of a rear loading refuse truck and illustrating the packing blade and fallback shield and the operating mechanism embodying the invention.The packing blade and fallback shield are shown in their starting and final position in which the packing blade covers the outlet opening during transport of the vehicle and loading of refuse into the tailgate; Figure 2 is a view similar to Figure 1 showing the packing blade in its raised position after the sweep cylinders have been retracted to complete the first sequential step in the method of operation of the invention; Figure 3 is a view similar to Figure 1 showing the packing cylinders extended after the second step of operation is complete and the packing blade is in a substantially horizontal position with its lower edge above the rear portion of the hopper bottom and the fallback shield is in its lowermost position;; Figure 4 is a view similar to Figure 1 after the third step has been completed by extension of the sweep cylinders swinging the lower end of the packing blade downwards and forwards, moving and compacting the refuse toward the outlet opening and in position for the fourth step which completes the cycle by retraction of the packing cylinders, moving the packing blade and fallback shield to their final and starting position shown in Figure 1.

Referring to Figure 1, a tailgate is generally shown by the reference numeral 10, the tailgate having vertical side walls 12 and 14, a roof 16, and a hopper-like bottom 18. The side walls 12 and 14 and the bottom 18 define a rear refuse inlet opening 20 through which refuse is dumped into the bottom 18, and a forward refuse outlet opening 22 through which the compacted refuse is pushed out of the tailgate.

The tailgate 10 is mounted at the rear of the body 24 of the refuse vehicle, the vehicle body being shown only in fragmentary form. The refuse enters the vehicle body through the tailgate outlet opening 22. The implements for compacting, moving and guiding the refuse through the tailgate are a packing blade 26 and a fallback shield 28 which extend across the width of the tailgate. The packing blade is generally rectangular and is supported along its upper end by a pair of packing blade links 30 pivotally connected at both ends by pins 32 forming a first movable axis. The other ends of the packing blade links 30 are pivotally connected to the walls of the tailgate by brackets 34 at each side through pins 36 forming a second axis, which is fixed. The brackets 34 are mounted to the tailgate walls at the upper end of inlet opening 20.A pair of hydraulic sweep cylinders 38 are pivotally connected at their piston rod ends 40, one at each side, to the. packing blade 26 by pins 42 on a third movable axis which is between the upper and lower horizontal edges of the packing blade 26.

The base ends 44 of the sweep cylinders 38 are pivotally connected to the tailgate wall at brackets 34 by pins 46 forming a fourth axis, also fixed, below and behind the pins 36 forming the second axis. The fallback shield 28 is pivotally connected at its lower end to the packing blade 26, preferably along the same first movable axis as the packing blade links 30 on pins 32. A pair of radial shield links 48 are pivotally connected, one at each end by pins 50 to the upper end of the fallback shield 28. The pins 50 form a fifth, movable, axis providing articulation to the fallback shield. The other ends of links 48 are pivotally connected to the walls adjacent the upper rear portion of the tailgate by pins 52 which forms a sixth axis, which is fixed.

A pair of packing cylinders 54 are pivotally connected at their piston rod ends 56 to the packing blade 26 at each side thereof, preferably on the first movable axis at pins 32 forming a common pivotal axis for the top of the packing blade 26, packing blade links 30, the lower end of fallback shield 28 and cylinders 54. The upper base ends 58 of the cylinders 54 are pivotally connected, one at each side of the walls adjacent the upper forward end of the tailgate by pins 60 forming a seventh axis, also fixed, about which each packing cylinder 54 is free to pivot as it is being extended.

It should be particularly noted that both ends of the fallback shield 28 are pivotally mounted for motion, at the ends of the packing blade links 30 and the ends of the radial shield links 48 which are mounted at their other ends as far apart as possible to establish nearly parallel linkage to accomplish the desired translation of the fallback shield 28. A baffle wall 62 extends downwards from the upper forward end of the tailgate. A scraper blade 64 is mounted on the lower end of the baffle wall 62 with its lower end in contact with the forward face of the fallback shield 28. The lower end of the scraper blade 64 defines the upper end of the refuse outlet opneing 22.The pins 52 are so located and the forward face of the fallback shield 28 is so configured that, as the upper end of the fall back shield 28, at moving axis 50, is rotated about the sixth axis at pins 52, the scraper blade 64 remains in contact with the shield 28.

In operation, the sweep cylinders 38 and the packing cylinders 54 are extended and retracted in four separate sequential steps providing the method of moving the packing blade and fallback shield to compact and move refuse through the tailgate on hopper bottom 18. Initially, the packing blade 26 is held adjacent to the refuse outlet opening 22 by the extended sweep cylinder 38, retaining refuse previously discharged into the vehicle body 24, as shown in Figure 1. Refuse is loaded into the tailgate 10 through the inlet opeining 20 onto the hopper bottom 18. When the hopper bottom 18 has been filled to capacity, the first sequential step is initiated and the sweep cylinders 38 are retracted, swinging the lower end of the packing blade 26 to the rear through piston rods 40 pivotally connected to the blade 26 at pins 42.The base ends 44 of sweep cylinders 38 swing to a small degree about the fourth stationary axis formed by pins 46 as the blade 26 is rotated about the first movable axis formed by pins 32. Since the packing cylinder 54 is not actuated at this time, the fallback shield 28 is retained in its stationary substantially upright position as the first axis at pins 32 and the fifth axis at pins 50 remain stationary. On the completion of this first, retraction step, the mechanism is in the position shown in Figure 2.

In the second sequential step the packing cylinders 54 are extended, moving the mechanism from the position shown in Figure 2 to that shown in Figure 3 by swinging of the upper end of the packing blade 26 through piston rods 56 downwards and rearwards to a substantially horizontal position with its lower edge above the rear portion of the hopper bottom and translating the fallback shield 28 to a lower rearward position to form a refuse transport and compaction path swinging the first movable axis at pins 32 about the secondary fixed axis formed by pins 36 as the packing blade links 30 rotate clockwise. The third axis formed by the pin connections 42 of the sweep cylinders 38 to the packing blade 26 swings clockwise about the fourth axis formed at the pin connection 46 of the bases 44 of sweep cylinders 38, as the cylinders 38 remain in their extended positions.The upper end of the fallback shield 28 which constitutes the fifth axis formed by the pin connections 50 of the shield 28 to the shield links 48 swings clockwise about the sixth axis formed by pins 52. During this extension of packing cylinders 54, their base ends 58 swing freely in a clockwise direction about the seventh fixed axis formed by the pins 60.

In the third sequential step, the sweep cylinders 38 are extended, swinging the lower end of the packing blade 26 at the pin connections 42 forming the third movable axis to swing the packing blade downwards and forwards so as to move the refuse in a compaction and transport path against the hopper bottom and fallback shield. This third movable axis swings about the stationary first movable axis as the first and fifth movable axes are held stationary by the extended packing cylinders 54 which hold the fallback shield 28 in its stationary, passage-forming position. This moves the mechanism from the position shown in Figure 3 to that shown in Figure 4.

In the final, fourth step, the packing cylinders 54 are retracted. This causes the packing blade 26 to be swept upwards and forwards towards the refuse outlet opening 22, moving the refuse through the transport and compaction path as the fallback shield 28 moves upwards and forwards. As the extended sweep cylinders 38 are swung upwards their connections at the pins 42 swing the third movable axis about the fourth fixed axis at pins 46 connecting the bases 44 to the brackets 34. As the packing blade links 30 swing counterclockwise, the first movable axis at the common pin connections 32 swings about the second fixed axis at pins 36 and the upper end of fallback shield 28 at pins 50 forming the fifth movable axis swings about the sixth fixed axis at the rear ends of the radial shield links 48.This moves the mechanism from the position shown in Figure 4 to the final and starting position shown in Figure 1.

The use of radial shield links 48 to allow movement of the upper end of the fallback shield 28 relative to its lower end eliminates the strictly straight line or radial path of the prior art and permits a translation of the shield from the upper forward position shown in Figure 1 and 2 to the lower rearward position shown in Figures 3 and 4, forming an optimum passage for the compaction of the refuse. In step three as the packing blade is swung downwards and forwards and in step four as the packing blade is swept upwards and forwards, this passage is maintained by the simultaneous upward movement of the fallback shield. Since the top portion of the shield is not constrained to a strictly radial movement, as is the prior art structure with no shield link, the upper position of the shield is closer to the forward end of the tailgate housing, permitting the packing cylinders 54 to be mounted closer to the front as well, and producing a greater angle between the axis of the packing cylinders and the packing blade link, which in turn increases the effectiveness of the packing cylinders 54 to lift the packing blade and hence increase the compaction of a given load.

Claims

1. A tailgate for a rear loading refuse vehicle, said tailgate having wall means including spaced vertical side walls and a hopper bottom defining a rear refuse inlet opening, and a forward refuse outlet opening, the combination of a packing blade and fallback shield and mechanisms for actuating the blade and the shield comprising: a generally rectangular packing blade extending across said tailgate; a pair of radial packing blade links each pivotally connected at one end, one at each side to the upper end of the packing blade, the other ends of the packing blade links being pivotally connected to the wall means adjacent the upper end of the inlet opening; a pair of hydraulic sweep cylinders each pivotally connected at one end, one at each side to a point between the upper and lower horizontal edges of said packing blade, the other ends of the sweep cylinders being connected to the wall means adjacent the upper end of the inlet opening subjacent the pivotal connection of the packing blade to the wall means, an articulated fallback shield extending across the tailgate being pivotally connected at its lower end to the packing blade; a pair of radial shield links each pivotally connected at one end, one at each side to the. upper end of the shield, the other ends of the shield links being pivotally connected to wall means adjacent the upper rear portion of the tailgate; and a pair of hydraulic packing cylinders each pivotally connected at its upper end to the wall means at the upper forward end of the tailgate, the other ends of these cylinders being pivotally connected to the upper end of the packing blade.

2. A tailgate according to claim 1 and further comprising a baffle wall extending across the tailgate and downwards from the top forward end of the tailgate and a scraper blade extending across the tailgate and attached to the lower end of the baffle wall and extending downwards and rearwards into contact with the forward face of the articulated fallback shield.

3. A tailgate according to claim 2 in which the scraper blade constitutes the upper end of the forward refuse outlet opening.

4. A tailgate according to any one of claims 1 to 3 in which the piston rod end of the sweep cylinder is pivotally connected to the packing blade and the base ends of the sweep cylinders are connected to the wall means.

5. A tailgate according to any one of claims 1 to 4 in which the fallback shield is pivotally connected at its lower end to the packing blade and the radial packing blade links on a common pivotal axis.

6. A tailgate according to any one of claims 1 to 5 in which the packing cylinders have their base ends connected to the wall means and their piston rod ends connected to the upper end of the packing blade and the radial packing blade links on a common pivotal axis.

7. A tailgate according to claim 6 in which the fall back shield is pivotally connected at its lower end to the packing blade, radial packing blade links and packing cylinders on a common pivotal axis.

8. A method of loading and compacting refuse through a tailgate assembly and into a rear loading refuse vehicle, the tailgate having wall means forming spaced vertical side walls and a hopper bottom defining a rear refuse inlet opening and a forward refuse outlet opening, the implements for loading and compacting being a packing blade and a fallback shield, and the mechanism for actuating the implements including: a pair of packing blade links pivotally connected along a first movable axis, one link at each side, to the upper end of the packing blade, the other ends of the packing blade links being pivotally connected to the wall means along a second fixed axis adjacent the upper end of the inlet opening; a pair of sweep cylinders pivotally connected along a third movable axis, one cylinder at each side, to a point intermediate the upper and lower horizontal edges of the packing blade, and the other ends of the sweep cylinders being pivotally connected to the wall means along a fourth fixed- axis adjacent and below the second axis; an articulated fallback shield pivotally connected at its lower end along the first movable axis to the packing blade and packing blade links; a pair of radial shield links pivotally connected along a fifth movable axis, one link at each side, to the upper end of the shield, the other ends of the shield links being pivotally connected along a sixth fixed axis to the wall means adjacent the upper rear portion of the tailgate; a pair of packing cylinders pivotally connected on the first movable axis at their lower ends, one cylinder at each side, to the packing blade, packing blade links and fall back shield, the upper ends of the packing cylinders being pivotally connected to the wall means along a seventh stationary axis adjacent the upper forward end of the tailgate; the method comprising the following sequential steps: swinging the packing blade about the first movable axis away from the refuse outlet opening by retracting the sweep cylinders, the fallback shield remaining stationary in a substantially upright position; swinging the upper end of the packing blade downwards and rearwards to a substantially horizontal position with its lower edge above the rear portion of the hopper bottom and transiating the fallback shield to a lower rearward position to form a refuse transport and compaction path by swinging the first movable axis about the second fixed axis, swinging the third movable axis about the fourth fixed axis, and swinging the fifth movable axis about the sixth fixed axis, through the extension of the packing cylinders as they freely swing about the seventh fixed axis; swinging the lower end of the packing blade downwards and forwards thereby moving the refuse in a compaction and transport path against the hopper bottom and fallback shield by swinging the third movable axis about the first movable axis as the first movable axis is held stationary along with the fifth movable axis through extension of the sweep cylinders as they freely swing about the fourth fixed axis; sweeping the packing blade upwards and forwards towards the refuse outlet opening thereby moving the refuse through the refuse transport and compaction path while the fallback shield is moved upwards and forwards by swinging the third movable axis about the fourth fixed axis while the first movable axis swings about the second fixed axis and the fifth movable axis swings about the sixth fixed axis through retraction of the packing cylinders as they freely swing about the seventh fixed axis.

9. A tailgate for a rear loading refuse vehicle substantially as described with reference to the accompanying drawings.

10. A method of loading and compacting refuse through a tailgate assembly and into a rear loading refuse vehicle substantially as described with reference to the accompanying drawings.