The present invention relates to trash collection receptacles, and more particularly to a dumpster that empties quickly without the need of shaking or banging the dumpster using the hydraulic lifting-tilting system.
Dumpsters and other trash receptacles are typically unloaded using large trash collection trucks with hydraulic lifting-tilting systems that lift and tilt the dumpster to an inverted position. In the tilted position the trash is no longer supported by the dumpster's floor, and a portion of the trash is pulled by gravity into the bay of the trash collection truck through the collection port. Even though the dumpster is fully or partially inverted, a residual portion of trash tends to be retained therein, adhered to the sidewalls and rim of the dumpster. Adhesive-like materials, such as proteinaceous mixtures, sugars, starches, and other polymeric materials, typically hold the residual trash. To dislodge the residual trash the truck's hydraulic system is used to violently shake and bang the dumpsters. The violent action is relatively effective at breaking loose the retained trash, however, the shaking and banging is noisy, it bends and knocks paint off the dumpsters, and it applies a tremendous strain on the trash collection truck's hydraulic lifting-tilting system. The strain results in much higher maintenance cost of the hydraulic lift system which is often the largest single maintenance issue on the entire truck because of the multiple pivot points and their respective pins, bushings and related parts. The cost directly attributable to shaking and banging dumpsters is on the order of several thousand dollars per month per truck at current prices. There are an estimated 140,000-160,000 trash collection trucks with hydraulic lifting-tilting systems in the United States, and the annual maintenance cost for the hydraulic lifting-tilting systems alone is several billion dollars.
In many cases, the moving arms on the truck are lubricated at least daily, and the overall cost of this and other maintenance is severe enough to make frequent new truck purchases a viable option to extended maintenance.
As another factor, the noise that is produced during trash collection and generated during the process of violently shaking and banging to dislodge the residual trash limits the collection hours during which the public will accept the disruptive noise, and requires (for example) a municipality to purchase, use, and maintain more trucks for fewer working hours.
In one aspect the invention is a waste dumpster that includes a container defined by vertically oriented walls, a fixed floor that closes the bottom of the dumpster and a hinged lid opposite the floor. A moveable floor is above the fixed floor and moves unaided in the walled container depending on the orientation of the dumpster. The moveable floor can be a planar member congruent in size and shape to the fixed floor and coupled to the fixed floor by a plurality of fixed length restraining means that define the movement of the moveable floor when the container is tilted from a non-upright position towards an inverted position. The movable floor has flexible edges coplanar with the remainder of the movable floor for allowing the movable floor to move more easily when the container is tilted.
In another aspect, the waste dumpster is a container defined by vertically oriented walls, a bottom area defined by the walls and a top opening opposite the bottom area of the dumpster. A moveable floor is adjacent the bottom area and moves unaided in the walled container depending on the orientation of the dumpster. The moveable floor includes a planar member congruent in size and shape to the bottom area and is coupled to the vertically oriented walls by a plurality of fixed length restraints that define the movement of the moveable floor when the container is tilted from a non-upright position towards an inverted position. The movable floor has flexible edges coplanar with the remainder of the movable floor for allowing the movable floor to move more easily when the container is tilted.
In another aspect, the invention is a method of collecting trash from a dumpster. In this aspect the invention includes the steps of engaging, using a hydraulic lifting-tilting system, a dumpster that includes a movable floor that is fixed to bottom portions of the dumpster to define a modest range of travel for the movable floor; and in which the moveable floor has flexible edges coplanar with the remainder of the movable floor; raising the dumpster from its storage location to a position substantially above a collection port of a trash collection truck; and tilting the dumpster from an upright orientation towards an inverted orientation so that the moveable floor drops a predetermined length defined by the range of travel from the bottom of the dumpster, to thereby push trash out of the dumpster through a top opening, and so that the movable floor shakes the dumpster when the movable floor reaches its defined range of travel to further dislodge adhered trash.
The foregoing and other objects will become more readily apparent by referring to the following detailed description and the appended drawings.
Referring now to the drawings, and particularly to
The illustrated dumpster 10 has forklift channels 30 that receive and are engaged by forks on a trash collection truck 31 fitted with a hydraulic lifting-tilting system broadly designated at 32. The dumpster 10 has a moveable false floor 22 comprised of a planar member that substantially forms the cross-sectional area of the floor. Attached or otherwise a part of the planar member are a plurality of upper coupling elements 33, on a lower side of the planar member (moveable false floor 16). A plurality of lower coupling elements 34 are fixedly attached to the dumpster 10 proximate to the bottom 17. There is a restraining means comprised of a plurality of connecting elements illustrated as the chains 35 attached to upper coupling elements 33 and lower coupling elements 34. The connecting elements in unison provide the moveable false floor freedom to fall a predetermined length toward the (open) lid 21 to push out trash when the dumpster 10 is tilted toward an inverted orientation as shown in
The restraints 23 extend to a predefined length. This is shown in
The dumpster 10 can include a plurality of stops 40 that prevent the moveable false floor 22 from hitting the plurality of lower coupling elements 34. The stops 40 can be selected to also impart noise dampening as the floor returns to the bottom, as well as stop the movement of the floor. Examples of noise dampeners are rubber pads, springs, pressure release pistons, and the like.
The moveable false floor 22 can additionally be aligned with a guiding means 41, which is shown in the corners formed by two of the sidewalls 14, 16. The guiding means 41 comprises a plurality of vertical longitudinal rails and intersecting slidable members. Examples of slidable members are bearings, rings, wheels, and pipes. Examples of vertical longitudinal rails are bars, pipes, angle iron, tube steel, and the like. More elaborate alignment systems, such as rack and pinion systems can be used, but in general are too expensive and not robust enough for the application.
These represent two possibilities for the flexible edge, but are offered for illustration rather than by way of limitation.
In operation, the moveable false floor 22 starts to move towards the top when the dumpster 10 is tilted greater than about 90 degrees. As a practical matter, the dumpster 10 is normally inverted so quickly, that the moveable false floor 22 moves only a short distance before the dumpster is inverted. Likewise, when the dumpster 10 is tilted upright, the moveable false floor 22 starts to move towards the bottom when the dumpster is tilted to an angle less than about 90 degrees, but as a practical matter the rotation is so quick, that very little movement of the floor 22 occurs before the dumpster 10 is upright, so alignment is less of an issue than one might speculate. If the trash collection truck 31 has a very slow operating hydraulic lift-tilt system 32, the guiding means operation will delay movement by the false floor until the dumpster is approaching a fully inverted orientation.
The invented apparatus changes the method of collecting trash. In a conventional collection, after tilting the dumpster from an upright orientation towards an inverted orientation, the hydraulic lift-tilt system is used to shake the dumpster, and if the design to the dumpster permits, the dumpster is banged on the collection port of the truck to dislodge the trash. With the invented dumpster the moveable false floor drops a predetermined length from the bottom of the dumpster, wherein said dropping false floor pushes trash out of the dumpster through the top opening, and upon reaching the predetermined length the floor is abruptly stopped causing the dumpster to shake therein dislodging adhered trash. No banging or shaking is performed by the trash collection. When the invented dumpster is returned to the upright position, the moveable false floor moves back to the bottom. The method reduces the time required for emptying the dumpster, as there is no shaking or banging step.
It is to be understood that the foregoing description and specific embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention, which is therefore understood to be limited only by the scope of the appended claims.
The present invention is related to Ser. No. 11/789,610 filed Apr. 25, 2007 for “Dumpster with a Movable False Floor and Method of Collecting Trash using the same,” and now U.S. Pat. No. 8,944,276.