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This invention provides a compaction device for use on refuse collection and transportation vehicles having a rear loading system, comprising:
- a shroud consisting of two side walls, a front wall, a rear wall for coupling with the vehiche body, an arc-shaped bottom (hopper), and means capable of conveying and compacting refuse into the vehicle body, consisting of:
- a plate provided with two pins projecting from the plate upper edge which can slide within a pair of straight-lined guides provided on the side walls of the shroud in an upper wall only;
- a pair of connecting rods hinged on one side to the side wall frame, at a point near the front wall of the shroud and on the other side to a lower edge of said plate, for guiding said lower edge along a curvilinear path during the up and down movements of the plate;
- a shovel hinged to the plate lower edge;
- a pair of plungers fitted outside the side walls of the shroud, for driving displacements of said plate along said guides;
- a pair of plungers hinged on one side to said plate and on the other side to arms secured to said shovel for driving rotations thereof around a hinging point.
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Compaction systems for use in collecting and transporting of refuse, based on the principle referred to as a so-called "articulated monoshovel", are known and widely spread throughout the world.
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The system comprises a plate having a shovel hinged at a lower end thereof, the shovel being driven by a pair of plungers for rotation around its hinging point, thereby causing its lower end (base) to describe an arc of a circle, to pass from an open position to a closed position. The entire plate and shovel assembly is slidable in a direction from bottom to top and viceversa inside the side walls of a shroud-loading hopper coupled to a body platform mounted to a truck, generally with a given, forwardly oriented inclination to the vertical from the body platform.
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In the various embodiments as presently used, the manner by which the shovel is hinged to the plate and the mode of causing its rotation are essentially the same, and do not show, in fact, any substantial differences in all of the proposed solutions.
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On the contrary, the translational movement of the plate secured to the associated articulated shovel for conveying and compacting the refuse from the bottom of the hopper to the vehicle body platform, which platform is, in fact, placed at a higher level than the hopper bottom, is in the prior art embodiments basically achieved according to two systems, that is, either
- a. by sliding movement on guides formed in the side walls of the loading shroud-hopper, or
- b. by means of a crank mechanism causing said translation to be performed through an arc of circle.
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In each of said systems some advantages and drawbacks are implied.
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The solution using side-guides permits the plate to have a linear conformation, which has to find a point of correspondence in the front wall of separation from the vehicle body, placed in an upper area of the shroud in order to cause the refuse to enter the vehicle body.
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However, the drawback here is that the length of the guides has to be such as to comprise the length of the plate which must be supported on two (lower and upper) points, plus the length of sliding movement, so that, in their lower part, said guides have to extend also into the area of the hopper where refuse is dumped.
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This solution, therefore, implies all of the unadvisabilities that are involved in the presence of refuse precisely in the area where the guides and associated shoes or rolls supporting the plate are subjected to higer wear as a result of the refuse counterthrust during the compaction step.
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Furthermore, due precisely to the necessity that said guides should be extended into this area, the guide wings must be inwardly directed, as a result of which the shoes or rolls for sliding and supporting the plate are also involved in the refuse area, with severe problems of maintenance as a consequence, since in order to replace the shoes or the rolls the plate itself must be removed from the shroud.
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Finally, since these shrouds have to be coupled to a truck body mounted in a rear portion of the truck, the shroud size has to be contained within the standard limits imposed for equipment jutting out from a rear axle of a vehicle.
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Therefore, the inclination of these guides to the vertical has to be determined by keeping in mind said limit size (from the end of vehicle body to the imposed jutting-out limit thereof), so that this frequently gives rise to hard situations with shroud-hopper terminating to a limit of said size, and difficulties in having further space available for fitting such accessory devices as are necessary for lifting and tipping a container to be dumped.
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Embodiments in which translation occurs through crank mechanisms imply a path in the form of an arc of a circle along which the plate is driven and as a result of which the plate will be brought to occupy hopper space in the area where access for dustbins to be dumped takes place, the plate interfering with these latter or their covers as a consequence.
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Moreover, the circular mode of movement, due to the necessity of maintaining contact between the plate and the front wall partially closing the way towards the vehicle body to convey refuse into this body, requires use to be made of an arc-shaped construction for the plate which is more expensive and complicated as compared with a straightlined costruction, and finally also the bottom of the hopper may have to show a non-homogeneous outline, according to the type and combination of arcs that are described by the lower part (base) of the shovel.
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The present embodiment is characterized in that the translational movement of the plate and shovel assembly is achieved by using a particular combination of connecting rods and rectilinear sliding guides, wherein a pair of connecting-rods are hinged, on one side, to the lowermost area of the plate and, on the other side, to the side walls of the shroud at a location near the front area of access to the hopper, and two pins protruding from the upper edge of the plate are slidlingly received in a slot in a rectilinear guide provided in the upper walls of the shroud.
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Said rectilinear guides are channel sections having a longitudinal slot traversed by the pins, with their base being flush with the inside of the shroud walls and with their wings being outwardly turned.
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Said pins, supported by a shoe or roll, as an alternative, are able, under the effect of two plungers placed outside the shroud walls, to cause the plate-shovel assembly to follow a translational path in a direction from bottom to top and viceversa.
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Advantageously, the conformation of said guides with their guide wings outwardly turned, permits maintenance of the shoes or rolls to be easily performed, their possible replacement being able to take place from outside the shroud walls, without any removal of the plate being required.
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Now, the invention will be described in detail as an example only, with reference to the annexed figures wherein:
- figures 1 to 3 are schematic side views of the compaction device according to the invention with the different handling mechanisms for handling the plate and shovel, in different operative steps;
- Figure 4 is a front view of the compaction device according to the invention.
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Referring now to the above figures, a vehicle body is shown at 1, in which refuse is compacted and collected by using the compaction device of the invention.
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This device consists of a shroud-hopper, indicated by reference numeral 2 as a wohle.
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Said shroud has two side walls 3, a front wall 4 for refuse or dustbin access, a rear wall 5 for coupling with a vehicle body, the rear wall 5 being closed at the top by a wall 6 which at its lower end provides a point of reference 7 to the inside surface of the movable plate, from which point, an opening 8 extending up to the vehicle body platform permits the refuse to enter the vehicle body. Finally, from the level of the body platform an arcuated bottom 9 extends downwardly into the lower part to raise again up to the access threshold at a given level of the front wall for garbage dumping, so as to define the base of a loading hopper.
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Placed inside said shroud-hopper are the devices for conveying and compacting refuse into the vehicle body, which comprise:
- a plate 10 capable of moving in a direction from bottom to top and viceversa, and a shovel 11 hinged through pins 12 to the lower edge of plate 10;
- two guides 13 substantially consisting of channel sections placed with their base at level with and inside the side walls of shroud 2 and having wings outwardly turned.
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Formed in the base of said channel sections is an elongated slot 14 which slidingly receives pins 15 extending from the upper edge of plate 10 and having shoes 16 fitted thereon which provide for greater bearing surface on the wings of the sliding guide, thereby to improve resistance to distortion of the assembly.
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Guides 13 are rectilinear guides and translational movements of plate 10 are provided by a pair of plungers 17 fitted outside the side walls of shroud 2 and arranged to act on pins 15 protruding from the upper edge of plate 10.
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Thus, plungers 17 drive the movement of plate 10 by said pins 15 sliding across the longitudinal slot 14, which pins 15, supported on shoes 16, run along the portion of guide 13 provided for translational movement of the plate-shovel assembly.
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The lower part of plate 10 is, on the contrary, guided in its movement by a pair of connecting rods 18 that are hinged, on one side, to the lower edge of plate 10 and, on the other side, to the frame of the side walls of shroud/hopper assembly, at a point 19 in poximity to the front wall of this latter.
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The fact that only the pins protruding from the upper edge of plate 10 are moved along the guides 13, permits these guides to be short in length, thereby obviating the necessity to have the guides continued towards and into the bottom of the shroud/hopper assebly where the guides would interfere with the refuse being dumped.
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Hinged to the lower edge of plate 10 is the shovel 11. The shovel 11 has a pair of arms 20 attached thereto, and hinged to these arms 20 is the rod of a plunger 21 which is in turn hinged, on the opposite side, to plate 10 at point 22.
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Movement of plunger 21 causes the shovel 11 to rotate around pins 12 at the lower edge of the plate.
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The bottom 9 of the shroud/hopper assembly is arc-shaped, so that the lower edge of the shovel, during rotation around pins 12 and in the path of translation of the plate/shovel assembly, will follow said arc while maintaining contact with the bottom of the hopper so that all of the refuse to be compacted is conveyed into the vehicle body.
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The operative sequence of the above-described device is as follows:
- At the end of a compaction cycle and, thus, at beginning of the subsequent cycle, the shovel is in the position shown with a solid line in figure 1, with the plate 10 being fully lifted.
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At this point plungers 21 are operated and cause the shovel to rotate in an anticlockwise direction to bring it in a so-called open position, shown in dashed line, figure 1.
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Now, the plungers 17 are operated and the retraction of these plungers 17 causes the plate 10 to slide downwardly, whereby the plate-shovel assembly is moved to the position in figure 2.
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During this movement, the lower edge of the plate is guided by the connecting rods 18 causing it to move along a circular arc having a center at point 19.
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Now, the plungers 21 are driven in extension to move the shovel in a clockwise direction to bring it to the position in figure 3. During this movement, the lower edge of the shovel will slidlingly move in contact with the arcuated bottom of the shroud so as to collect all of the refuse, whwreupon the plate-shovel assembly can be moved again upwardly, while maintaining the shovel in the closed state until position of figure 1 is reached once more.
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During this movement the refuse is lifted to be pushed and compacted into the vehicle body through the opening 8 provided in the rear wall 5 from point of reference 7 to the platform of vehicle body.
Advantages
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The hinging of the connecting rod to a fixed point in the side walls in proximity to the front wall of the hopper, describes an arc whose concavity is in the direction of the vehicle body and this permits the bottom of the hopper to be given a curvilinear profile of continuity from bottom towards the body platform, thereby enabling the end (base) of the shovel to constantly move in contact with the hopper bottom, in the path for conveying refuse into the inside of the vehicle body.
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Said connecting rod, besides performing the function of guiding the lower part of the plate during its translation, also acts as a counterthrust means against reaction due to the pressure as exerted by refuse bulk in the compaction step (with substantial advantages over the solution using guides in that area where both maximum wear and the interference of refuse with sliding movement of the roll or shoe occur).
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The guide is straight-lined in shape and this permits shoes to be used as supports for the pins; it is placed in an upper part of the door and, thus, in an area strange to the presence of refuse; it is of a short length limited to the translational movement only, that is the path the pins protruding from the upper edge of the plate have to perform; and due to the fact that said guide is free from any constraint with respect to the base of said plate hinged to said swinging connecting-rod, it can assume such inclination to the vertical as is desired in order to obtain optimum profile of the plate-shovel assembly for conveyance and compaction of refuse into the vehicle body.
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Moreover, said point of contact-reference to which the internal surface of the plate has to constantly adhere during its movement in order to convey and compact refuse into vehicle body, has been suitably set so that the profile (inside surface) of contact-reference of the plate should be basically linear, in spite of the use, in a lower part, of a connecting rod and, in an upper part, of a guide which is linear, but relatively short in length.
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These features permit a plate to be constructed which is non-arcuated but substantially rectilinear in shape, as a result of which a more simple and less expensive product is obtained.
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The fact that said upper guide of short length is linear in shape (that is a straight-lined guide with no curves therein), permits sliding shoes to be used, which in comparaison with hypothetical rolls provides the benefit of having a wider bearing base for counteracting the pressure thrust on the guide wings.
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By these arrangements it has been attempted to achieve all of the simplicity advantages offered by a linear construction of the plate, typical of the solutions using guides only, and which are: maximum utilization of space for access of the bins into hopper without interference with the moving plate, an evenly curvilinear configuration of the hopper bottom for conveyance of refuse into vehicle body, together with all of the benefits resulting from using a connecting-rod or crank, in lieu and place of guides, in the lower part only of the hopper where refuse is handled and where maximum thrust and wear occur.