Patent Publication Number: US-2019177085-A1

Title: Multi-Compartment Rear Load Packer

Description:
RELATED APPLICATIONS 
     The present application claims the benefits of the filing dates under 35 U.S.C. § 119(e) of U.S. Provisional Applications No. 62/174,748 filed Jun. 12, 2015 for “Three Compartment Refuse Packer With Anti-Spill Plates”, and No. 62/161,996 filed May 15, 2015 for “Three Compartment Rear Load Packer”, and under 35 U.S.C. § 120 of U.S. application Ser. No. 15/568,621 filed Oct. 23, 2017 for “Three Compartment Rear Load Packer” as a U.S. National Stage entry of International Application No. PCT/US2016/032432 filed May 13, 2016. 
    
    
     BACKGROUND 
     The present invention relates to trucks for refuse packing, and especially to truck bodies adapted to pack recyclable refuse. 
     Some communities desire the separate recycling of three kinds of materials: metals, paper goods, and organics. Although truck bodies are known for providing three compartments for receiving, packing, and ejecting three types of recyclables, such bodies have one sump, one sweep blade and one pack blade for each compartment, with two compartments loaded from the rear of the body and one compartment loaded from the sidewalk side of the body. This configuration has two main disadvantages. First, three sets of power and actuation components are required, with the resultant high cost of components and encroachments on available space for the packing compartments. Second, curbs, poles, signs and other roadside obstacles can inconvenience and endanger the collection worker at the side sump. 
     SUMMARY 
     The present invention is generally directed to a multi-compartment, sweeper-type rear loading refuse packer for a truck body, wherein a single pack blade cooperates with a multi-section sweep blade. 
     The sweep blade can be unitary, with multiple sections connected together and driven as a unit or the sweep blades can be segmented, with each driven individually. 
     This enables the collection worker to separately load all three types of recyclables at the rear of the truck, and reduces the number and space occupied by the power and actuation components. 
     In a three compartment configuration, the sweep blade has two spaced apart slots which cooperate with a respective two collection sump dividers that extend to the openings of the compartments. This defines three collection sumps and three channels leading into a respective three longitudinal packing compartments. With a unitary sweep blade option, the blade comprises opposed top and bottom continuous edges of greater lengths than opposed lateral edges, with an optional curvature from top to bottom, and with laterally spaced slots extending at least halfway from the bottom edge toward but not reaching the top edge. With a segmented sweep blade, the slots extend the full blade height from top to bottom. The sweep blade spans all the collection sumps from above and the two vertical slots are laterally spaced at a distance corresponding to the lateral space between the compartment dividing walls, thereby defining three blade sections drivable toward through the collection sumps toward the loading floors of the compartments. 
     Yet another embodiment is directed to a rear load refuse body comprising three packer compartments extending longitudinally from the front toward the back of the body; three laterally divided collection sumps at the lower back of the body, for receiving a respective three loads of segregated refuse; and a sweep blade extending laterally across all the sumps, with three sections corresponding to the three collection sumps. The sweep blade sections are movable respectively within each sump. A first drive system is provided for sweeping the entire sweep blade whereby each sweep blade section sweeps through each respective collection sump and thereby transports collected refuse toward the floor of a respective compartment. A single pack blade is coupled to the sweep blade and driven by a second drive system. As the pack blade is displaced obliquely, it lifts the sweep blade obliquely such that the sweep blade and pack blade push the collected refuse into respective compartments, against compaction faces carried on respective ejection cylinders in the compartments. 
     In an ideal three compartment system, cost and space are minimized when the sweep blade is unitary with three sections and the first drive system for the sweep blade has only two hydraulic cylinders, but space savings are still achieved even when the sweep blade has three segments driven by a respective three cylinders. In both embodiments, space savings are achieved by the use of a single pack blade, with the associated second drive system consisting of two hydraulic cylinders. 
     As used herein, the terms “multiple” and “multi” mean “at least two”, and description of a compaction unit having multiple collection sumps or sweep blade having multiple sections according to the invention does not necessarily preclude the compaction unit from including an additional sweep blade and associated collection sump. The main advantage of the present invention is that for a compaction unit having a particular number of collection sumps with associated sweep blade sections, efficient operation can be achieved with fewer pack blades than the number of sweep blade sections. For example, in a hybrid three compartment packer, the compaction unit can have one conventional sump, sweep blade with dedicated drive, and pack blade with dedicated drive, in side-by-side combination with two other sumps having a two-section sweep blade and single pack blade according to one aspect of the invention. The inventive two-section sweep blade could be unitary or segmented, have either one or two associated drives, but with a single pack blade. Instead of the drive systems requiring six drives, only four or five drives would be required. This hybrid configuration would fall within the open-ended recitation of a multi-compartment, sweeper-type rear loading refuse compaction unit for a truck body, comprising a single pack blade pivotally connected to a multi-section sweep blade. 
     Another problem arises when the compaction unit is raised open for refuse ejection of the three compartments. There is a tendency for refuse in all three compartments to start dropping. This is undesirable, as the type of refuse in each compartment is different and must be offloaded separately. According to another improvement, this problem is solved by providing a sloped lower back end to the refuse compartments and two anti-spill plates cooperating with the sloped back end for blocking the lower portion of the outer two compartments. The two anti-spill plates hold the contents within the outside compartments, thus enabling the center compartment to be ejected first. Once the center compartment is unloaded, each of the outside compartments is uncovered in turn by lowering the respective anti-spill plate. 
     In a further feature to prevent spillage through the rear opening of one or more compartments, each having upper region and a lower regions, the anti-spill plate associated with a sump is displaceable to cover the lower region of the opening, and a seal plate is mounted on the body in vertical opposition to each anti-spill plate, to selectively cover the upper region of the opening. In the way the anti-spill plate and the seal plate confront and close the opening of the associated refuse compartment when the compaction unit is pivoted to the ejection position. 
     The anti-spill plates and seal plates can be advantageously used with any type of seep and pack blade configuration. Thus, an aspect of the invention is directed to a refuse truck having a refuse receiving body including a front, a back, a top, and a bottom, with at least one refuse compartment with an opening accessible at the back of the body, comprising; an anti-spill plate supported by the body, and rotatable between an open position away from a lower region of the opening and a closed position against the lower region of the opening; and a seal plate supported by the body, and rotatable between an open position away from an upper region of the opening and a closed position against the upper region of the opening. 
     The inventive principles described herein can be readily implemented in two, three, four or more compartment configurations. 
     In yet another advantageous feature, the compaction unit is pivotally connected to the body. In the loading position, the plurality of collection sumps at the back of the body are situated rearward of and below the compartment openings, for receiving a respective load of segregated refuse deposited over a rear loading ledge at the back of each sump. At least one divider wall extends between respective two adjacent sumps from the rear loading ledge to the ceilings of the respective two adjacent compartments at the compartment openings, thereby defining respective loading channels from the sumps to the compartments. Each divider wall has a back portion with a top edge extending forward along adjacent sumps and a front portion with a top edge that rises obliquely from the top edge of the back portion to the ceilings of the respective two adjacent compartments at the compartment openings. The pack blade covers the channels and is drivable toward and away from the ceiling on an obliquely linear path along the top edge of the front portion of the walls, between a bottom limit position and a top limit position. The pack blade remains a part of the compaction unit when the compaction unit is pivoted upwardly into the discharge position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows a conventional single compartment, rear-loading garbage packing truck; 
         FIG. 2  is a schematic representation of the steps in a packing cycle according to the present invention; 
         FIG. 3  is a top view of one embodiment of the present invention, showing the truck body with the roof removed; 
         FIG. 4 , is an exploded view showing the sweep blade as an integral unit that extends laterally the full width of the truck body and has two laterally spaced slits which extend vertically from the bottom edge of the blade at least half way to but terminating below the top edge of the blade; 
         FIG. 5  shows another embodiment for the sweep blade; 
         FIGS. 6 and 7  schematically show the operation of ant-spill plates; and 
         FIG. 8  is a view of the open rear of the truck corresponding to  FIG. 7 , showing the anti-spill plates. 
         FIG. 9  is a perspective view of the sweep blade, pack blade, and associated drive systems corresponding to position  2  in  FIG. 2 ; and 
         FIG. 10  is a perspective view of the sweep blade, pack blade, and associated drive systems corresponding to position  4  in  FIG. 2 . 
         FIG. 11  shows a fully open compartment at the back driver&#39;s side of the truck body that incorporates a seal plate with the anti-spill plate; 
         FIG. 12  corresponds to  FIG. 11 , with the seal plate closed and the anti-spill plate open; 
         FIG. 13  corresponds to  FIG. 12 , during the refuse collection mode of operation, whereby the sweep blade pushes material toward the open lower region of the compartment; 
         FIG. 14  corresponds to  FIG. 13 , in a detailed view of the sweep blade passing over the anti-spill plate; 
         FIGS. 15 and 16  show how the sweep blade pivots away to provide clearance for the anti-spill plate to pivot upwardly toward the lower region of the compartment opening in preparation for dumping another compartment; and 
         FIG. 17  shows the anti-spill plate and seal plate in the closed positions. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a conventional single compartment, rear-loading garbage truck  10 , including chassis  12 , wheels  14 , body  16 , and cab  18 . The body extends longitudinally from a front end  20  to a back end  22 , where a compaction unit  24  is integral with the body or supported by the chassis or both the body and chassis. Hydraulic cylinders  26  are mounted to the body or other support structure  28  to operate the compaction unit. 
       FIG. 2  is a schematic representation of the steps  1 - 4  in a packing cycle according to the present invention, which is directed to a sweep type compaction unit that can be incorporated into the overall truck and body represented in  FIG. 1 . The set of hydraulic cylinders  26  at the periphery of the body  16  can be adapted to operate the pack blade  30  and another set of cylinder (not shown) operate the sweep blade  32  through sump  34  into the pack compartment in body  16 . The upper edge of the sweep blade  32  is pivotally connected along a transverse axis, to the bottom edge of the pack blade  30 . The present invention is an improved truck body or compaction unit with efficient multi-compartment capability. 
       FIGS. 3 and 4  will be described below, for showing the detailed execution of the inventive concept for three packer compartments extending longitudinally from the front toward the back of the body, but the general operating principles will be described with respect to  FIG. 2 . Each compartment has a height defined between a loading floor  36  and a ceiling  38 , at a rear opening  40 . Three collection sumps  34  at the back of the body, situated rearward of and below the compartment openings  40 , receive a respective three loads  42  of segregated refuse (per steps  1  and  2  of  FIG. 2 ). Two laterally spaced divider walls  44  extend from the sumps to the ceilings of the compartments at the compartment openings, thereby defining three respective loading channels from the sumps to the compartments. The main body has two longitudinal walls  46  aligned with the divider walls  44 . Sweep blade  32  extends laterally across all the sumps  34 , and has three sections corresponding to the three collection sumps, wherein the sweep blade sections are movable respectively within each sump. 
     A first drive system is provided for pivoting each sweep blade section through each respective collection sump toward the floor of a respective the compartment (as shown in step  3  of  FIG. 2 ). A single pack blade  30  is displaceable in a linear oblique path toward and away from the sump  34 . The pack blade is retracted upwardly and the sweep blade pivoted toward the floor  36  for collection of refuse (per step  1  of  FIG. 2 ). The pack blade  30  is extended and the sweep blade is also extended in substantial alignment with the pack blade, and then pivoted toward the floor  36  in a sweeping action as shown in steps  2  and  3  of  FIG. 2 . As shown in step  4  of  FIG. 2 , the pack blade  30  is then retracted and in cooperation with the perpendicularly angled sweep blade  32 , pushes the swept refuse through the channels between divider walls  44  into compartment openings  40  while maintaining segregation of the refuse between the divider walls. The rearward edges  48  of divider walls  44  are positioned and inclined so that the oblique upward displacement of the pack blade  30  closely follows the edges of the divider walls. 
     It can be appreciated that the pack blade has a lower edge that is pivotally connected along a transverse axis to an upper edge of the sweep blade; a first drive system pivots the sweep blade around the transverse axis, over an included angle that follows the shape of the sump; and a second drive system displaces the pack blade with sweep blade obliquely from the sump to the floors of the compartments. 
       FIG. 3  is a top view of one embodiment of the present invention, showing the truck body  100  with the roof removed. The body has a frame  102  with front wall  104  and side walls  106 ,  108 . Two laterally spaced internal walls  110 ,  112  cooperate with the side and front walls to define three longitudinally extending packing compartments  114 ,  116 ,  118 . At the back end  120 , two longitudinally extending, laterally spaced dividers  122 ,  124  align with the walls  110 ,  112 , respectively. The dividers separate three distinct collection sumps  126 ,  128 ,  130 . The dividers  122 ,  124 , extend or are otherwise connected to the walls  110 ,  112 , so that three channels are formed, each having an associated sump and packing compartment. 
     As also shown in  FIG. 4 , the sweep blade  132  is an integral unit that extends laterally the full width of the body and has two laterally spaced slits  134 ,  136  which extend vertically from the bottom edge of the blade at least half way to but terminating below the top edge  138  of the blade. This defines three sweep blade sections  140 ,  142 ,  144 , preferably having a curvature adapted to sweep within the respective three curved collection sumps  126 ,  128 , and  130  as the slits  134 ,  136  pass over dividers  122 ,  124 . In this manner, a different type of recyclable can be placed in a different collection sump, and separately swept toward respective packer compartments  114 ,  116 , and  118  as the respective sweep blade cylinders  146   a ,  146   b , and  146   c  sweep the entire sweep blade  132 . Three sweep blade cylinders are shown but fewer can be provided. The sweep blade cylinders are supported within the frame on cross brace  148 , with linkages and associated actuation arms  150   a ,  150   b , and  150   c  connected to the back side, for sweeping blade  132 . 
     The pack blade  152  extends laterally across the body above the sweeper blade  132 , for oblique movement toward and away from the compartments. Pack blade cylinders  154   a ,  154   b  are shown mounted inside the body or frame for this purpose and connect to an additional cross brace  156 , but the pack blades can alternatively be mounted outside the frame. Braces  158   a ,  158   b  are also provided. The lower edge  160  of the packer blade is in essence pivotally connected along a transverse axis to the upper edge  138  of the sweep blade for cooperative movement as described with respect to  FIG. 2 . 
     Refuse in each compartment  114 ,  116 ,  118  is packed as the pack blade  30 ,  152  and sweep blade  32  as sectioned per  140 ,  142 ,  144 , push the refuse into the openings  40  at the rear of the compartments. The refuse is pushed against packing faces  162 ,  164 ,  166  on the ejection cylinders  168 ,  170 ,  172 . The cylinders retract as the compartments fill with packed refuse. When the truck is full, the entire compaction unit  24  ( FIG. 2 ) rotates upwardly to expose the compartment openings  40 . The ejection cylinders  168 ,  170 ,  172  are extended in sequence to push the refuse out the back end of the truck into three different dumping stations for the respective three different kinds of refuse. 
       FIG. 5  shows another embodiment  174  for the sweep blade. Each of the three sections is a distinct segment  176 ,  178 ,  180 . In all other respects, the relationship and cooperation with the pack blade are the same as described with respect to  FIGS. 2-4 . It should be understood that, as shown in  FIG. 5 , the present description of the upper edge of the sweep blade as being pivotally connected to the lower edge of the pack blade does not require literal mating on the edges or effective along the entire lateral extent of the edges. The main point is that the blades are connected so that the edges pivot. 
     Regardless of the number of compartments, sweep blade sections or segments, and sweep blade cylinders, only one pack blade is required, which can be actuated by only two internal or external cylinders. 
     When the compaction unit  24  is raised open for refuse ejection of the three compartments, there is a tendency for all three compartments to start spilling refuse. This is undesirable, as the type of refuse in each compartment is different and must be offloaded separately. 
       FIGS. 6-8  show an improved compaction unit  182  that can be used with any type of multi-compartment refuse packer to address this problem. The compaction unit  182  has an upper portion  184  pivotally connected at  186  to the upper portion of the main body  188  of the truck and a lower portion  190  that extends downwardly behind the main body of the truck and defines the sumps. The pack blade is located within the upper portion  184  and the sweep blade is located in the lower portion  190 . During collection, the pack blade runs up and down along oblique track  192 , which enables the path of the pack blade (described previously) to follow the similarly oblique edges  194   a  at the openings of the upper portion of the compartments of the main body of the truck. The upper edges  194   a  extend backward and downward from the area of the pivot  186 . The lower edges  194   b  at the lower portion of the openings angle downward and forward from the lower end  194   c  of the upper edges. Two anti-spill plates  196 ,  198  at the bottom of the sump with associated hydraulic actuators  200 ,  202  and linkages  204 ,  206  are provided for the two outer compartments. 
     When the truck is full and ready to unload ( FIG. 6 ), the sweep blade is opened (extended). The anti-spill plates are rotated into the up (closed) position, and the compaction unit is raised ( FIG. 7 ). The two anti-spill plates hold the contents within the outside compartments, thus enabling the center compartment to be ejected first. Spillage would tend to occur at the floors of the compartments, but this is prevented by the blocking effect of the anti-spill plates. Each anti-spill plate confronts or slightly enters the lower portion of a compartment opening, defined by the edges  194   b . This blocks the lower portion of the opening, while the packed refuse at the upper portion of each compartment opening has a natural angle of repose corresponding to the angle of the back edges  194   a  resulting from the operating angle of the pack blade. The anti-spill plates need only block the lower portion, which is preferably less than half of the full height of the compartment openings. Whereas the sweep blades pivot counterclockwise toward the openings, the anti-spill blades pivot clockwise toward the openings. 
     Once the center compartment is unloaded, each of the outside compartments is uncovered in turn by lowering the respective anti-spill plate.  FIG. 8  shows the back of the truck during the load ejection sequence of compartments A, B, and C, with the center compartment B fully open, compartment A during opening of the anti-spill plate, and compartment C with the anti-spill plate fully closed. 
     It should be understood that the anti-spill plates are inside the respective sumps, below the sweep path of the sweep blades when the compaction unit is in the collection position. Each anti-spill plate is displaceable out of the sump for confronting the bottom of the associated refuse compartment when the compaction unit is pivoted to the ejection position. 
       FIGS. 9 and 10  are perspective views of the sweep blade, pack blade, and associated drive systems corresponding to the respective positions  2  and  5  shown in  FIG. 2 , consistent with  FIG. 3  and representative of a unitary or segmented sweep blade as shown in  FIGS. 4 and 5 . 
       FIGS. 11 and 12  show an additional preferred feature, whereby the inadvertent spilling of the content of each side compartment can be further prevented during unloading. In a manner analogous to the anti-spill plates, a seal plate  208  is provided for each side compartment, such that the seal plates prevent the content from overflowing the top edge of the anti-spill plates  210 . Whereas the anti-spill plates pivot  212  from a low point at the back of the body upwardly toward the compartment end walls  214 ,  216 , and close a lower portion or region  218  of the compartment opening, the seal plates  208  pivot  220  from a high point at the back of the body downwardly toward the compartment end walls, closing an upper portion or region  222  of the opening. When deployed together during unloading of a given compartment, each pair of vertically opposed set of anti-spill plate  210  and seal plate  208  effectively block the entire rear opening of the compartment that is not being unloaded. 
     The back of the body is shown with angled profile  224  with an edge that can be fitted with resilient seals such as outer seal  226  and inner seal  228 . A straight (or as shown) correspondingly angled  230  seal plate  208  is pivotally connected with a drive system at the top, or near the roofline of the body. The outer seal  226  can be a strip, ridge, ledge or shaped plate fixed to the body whereas each of the two inner seals  228  would generally be a strip covering the two edges of the central compartment walls. The seal plate  208  extends over the upper region of the opening, down to the tops  232 ,  232 ′ of the vertical outer body support and vertical portion of the internal divider wall, which defines the lower region. 
     When the compaction unit is lifted, each lateral compartment thus has a rear opening with upper and lower regions. The upper region is subject to closure with the sealing plates and the lower region is subject to closure with the anti-spill plates, thereby preventing spillage while the central or other lateral compartment is being unloaded. As shown in  FIGS. 13 and 14 , during the compaction phase, the seal plates  208  are closed whereas the anti-spill plates  210  are open, to maintain an open lower region of the compartment for the sweep blade  234  and pack blade (not shown) to operate. In the packing phase, the hopper pan portion  236  of the sump has a recessed lower plate  238  that supports the flat, overlying, open anti-spill plate  210 , so the sweep blade passes closely over the anti-spill plate toward the open lower region of the compartment. The seal plates are closed, but the pack blade (not shown) can push refuse through the open lower region. 
       FIGS. 15-17  show the cooperation of the seal plates  208  and ant-spill plates  210  during the transition to the dumping phase, wherein initially, at least the lateral compartments must be closed as the compaction unit is raised. For one of the lateral compartments, the corresponding sweep blade  234  pivots or is otherwise angularly displaced from the packing position as shown in  FIG. 14 , to a dump position as shown in  FIG. 16 . At that point, the anti-spill plate  210  can be fully closed, as shown in  FIG. 17 . 
     In a three-compartment system, when the compartments are to be emptied, generally the central compartment is emptied first, while the lateral compartments are both sealed with the closed seal plates and closed anti-spill plates, as shown in to  FIG. 17 . During the transition to the dumping phase, the anti-spill plate pivots toward and closes off the lower region of the compartment opening as the sweep blade retracts. Preferably, the lateral edges of the anti-spill plate are provide with flexible wipers  242  to bear upon the inner edges  244  of body wall structure that define the lower region of the opening. As shown in  FIG. 15  these movements are coordinated to avoid interference by providing clearance  240 . After dumping from the central compartment, the equipment moves to another dump location and the seal plate and anti-spill plate of one lateral compartment are opened for dumping, as shown in  FIG. 11 , while the other compartment remains closed. The equipment is then moved whereupon the other compartment is fully opened. 
     As an alternative, the seal plates could be simply hinged, with each being heavy enough to stay closed and only open as a result of the pressure of the contents being pushed out the back end by the hydraulic ram. 
     It should be understood that a similar need for preventing spillage arises in a two-compartment or even four-compartment system. The anti-spill plates and sealing plates as described above can be readily implemented into any refuse body having multiple (at least two) compartments. 
     The combination of  FIGS. 1-4, 6, 7, 9 and 10  discloses other notable features of the divider walls  122 ,  124 , sweep blades  132  and pack blade  152  as integrated into a compaction unit  182  that is pivotally connected at  186  to the upper portion of the main body  188 . In the collection or loading position of the compaction unit (schematically represented in  FIG. 2  and shown according to an embodiment of the invention in  FIGS. 3, 6, 9 and 10 ), a respective plurality of collection sumps  126 ,  128 , and  130  are situated rearward of and below the compartment openings  114 ,  116 ,  118 , for receiving a respective load of segregated refuse deposited over a rear loading ledge  246  that spans the back of each sump. Two transversely spaced apart, shared unitary divider walls  122 ,  124  extend between respective two adjacent sumps from the rear loading edge  246  to the ceilings  38  of the respective two adjacent compartments at the compartment openings  40 , thereby defining the separation between respective loading channels from the sumps to the compartments. Each divider wall has (i) a back portion  248  confronting the loading ledge  246  and a top edge  250  extending at a shallow angle substantially horizontally forward along adjacent sumps, and (ii) a front portion  252  with a top edge  254  that rises obliquely at a steeper angle from the top edge  250  of the back portion to the ceilings of the respective two adjacent compartments at the compartment openings. In the embodiment shown in  FIG. 10 , the back portion  248  of the divider walls confronts the loading ledge  246  with the top edge  250  of the back portion  248  only slightly above the loading ledge  246 . 
     The pack blade  152  has a top  256  and a bottom  160 , overlying the channels and drivable toward the ceiling  38  on an obliquely linear path between a bottom limit position (position  2  in  FIGS. 2 and 152  in  FIG. 9 ) and a top limit position (position  1  in  FIGS. 2 and 152  in  FIG. 10 ). The sweep blade  132  is pivotally connected at its top  138  to the bottom of the pack blade and when the pack blade  152  is at the lower limit position the sweep blade  132  is rotatable between an extended position substantially aligned with the pack blade while covering the sump and a retracted position angled downwardly into the sump; toward the compartments. The top edges  254  of the front portion  252  of the divider walls begin to rise obliquely from the top edges  250  of the back portion  248  of the divider walls, at an inflection  258  located at the bottom limit position of the pack blade ( FIG. 9 ). The pack blade is in the form of a single, substantially flat plate that travels in parallel along the top edge of the front portion of the divider walls while pulling the closed sweep blades through the channels to the packed position shown in  FIG. 10 . 
     This can be viewed in an alternative way, as the pack blade  132  having a lower edge  160  that is pivotally connected along a transverse axis to an upper edge  138  of the sweep blade  132 . The hydraulic cylinders of first drive system  146  on the compaction unit pivot the sweep blade  132  around the transverse axis, over an included angle such that a lower edge  260  of the sweep blade follows the contoured surface of the sump (positions  2  and  3  in  FIG. 2 ), and the hydraulic cylinders of second drive system  154  on the compaction unit obliquely displace the pack blade with angled sweep blade and thereby raise the lower edge of the sweep blade from the sump to a packed position at the floors of the compartments (position  4  in  FIG. 2  and  FIG. 10 ). The back portions  248  of the divider walls extend from the loading ledge  246  to the packing position of the sweep blades. 
     It can be appreciated that for loading refuse, the pack blade  152  and angled sweep blade  132  are in the raised position ( FIG. 10  and position  1  in  FIG. 2 ). This is also the fully packed position (position  4  in  FIG. 2 ). As shown in  FIG. 10 , at the conclusion of a packing stroke the sumps are open for loading. The combination of low top edge  250  on the back portion  248  of the walls facilities cross loading of refuse, in that the refuse collector need not stand directly behind the sump targeted for deposit of a particular type of refuse. The collector can stand in any convenient position relative to a particular sump, conducive to lifting and rotating the refuse receptacle over the loading edge, into that sump. The steeper but still relatively low top edge  254  on the front portion  252  of the walls accommodates the obliquely up and down motion of a single overlying pack blade.