Waste compacting apparatus

Abstract

A waste compacting apparatus 10 has an outer framework 1, an inner compacting chamber 7, a compaction plate assembly, and a waste ejection assembly. The inner compacting chamber has a pair of spaced a

Description

Field of the Invention The present invention relates to apparatus for compacting waste. Background of the Invention Retail environments generate large quantities of paper and cardboard waste from packing and shipping materials. This waste accumulates quickly and occupies valuable storage space. Recycling and disposal of such waste is made easier by efficient compacting of the waste. US4232599 describes a waste paper compacter in which waste is compacted by a compacting ram to form bales of waste material. The compacter includes a bale ejector in the floor of the apparatus in the form of a tilting element which causes the bale to be tipped out of the compacter. The bale can then be received onto a forklift or hand cart placed in front of the compacter. Such an arrangement would generally be suitable for the production and ejection of bales which have a low height relative to their width and some manual handling of the bale may well be required. GB2569545 describes apparatus for compacting waste which is contained within a roll cage. Roll cages comprise a rectangular base with wheels beneath the base, and a three-sided cage framework extending upwardly from the base, with the cage open on one side. Roll cages are widely used for carrying and transporting goods but the cage framework is relatively light weight. The waste compacting apparatus described in GB2569545 allows waste to be compacted within a roll cage framework. The apparatus comprises a frame into which a roll cage filled with discarded packaging or other waste material is received. A pair of side plates then move inwardly to stabilise and support the sides of the roll cage during compaction of waste. Waste is then compacted by a pressure plate referred to as a, “platen” which is pressed downward by a hydraulic ram onto the waste in the roll cage. A pusher plate is then employed to urge the roll cage out of the apparatus. Material may be compacted in stages. The roll cage may be topped up with additional material in between the compaction stages. Roll cages have a modest weight limit, typically around 500kg, so are at risk of damage if a large pressure is exerted on the waste held within the cage. This means that waste cannot be highly compacted. Roll cages also often have a folding inner shelf which could interfere with the pressure plate during compaction, causing damage to the roll cage. It would be desirable to provide an improved waste compacting apparatus. Summary of the Invention According to one aspect of the invention there is provided a waste compacting apparatus comprising: an outer framework; an inner compacting chamber; a compaction plate assembly; and a waste ejection assembly for ejecting compacted waste from the apparatus; wherein the inner compacting chamber comprises a pair of spaced apart side walls and a base, wherein the side walls and base are fixedly attached to the outer framework; and wherein the inner compacting chamber is positioned such that the side walls and the base of the inner compacting chamber locate within an interior space of a roll cage when a roll cage is introduced into the framework; and wherein the compaction plate assembly includes a press plate which is moveable between an upper position and a lower position within the inner compacting chamber such that waste within the inner compacting chamber is compacted by the press plate; and wherein the waste ejection assembly comprises at least one pusher plate configured to move between a retracted position located at a rear region of the inner compaction chamber, and an extended position located at a front region of the inner compaction chamber. The side walls of the inner compacting chamber may be substantially parallel, and may be substantially vertically oriented. The side walls may be mounted on the base of the inner compacting chamber. The outer framework may comprise a base and a pair of side walls and the inner compacting chamber may be positioned within the outer framework such that the base of the inner compacting chamber is spaced apart from the base of the outer framework and the side walls of the inner compacting chamber are spaced apart from the side walls of the outer framework. The press plate may be moveable by means of a hydraulic ram. The outer framework may support side walls spaced apart from the side walls of the inner compacting chamber. The side walls of the inner compacting chamber may be spaced apart from the side walls of the outer framework by a distance of between 150 and 300mm. The outer framework may comprise a base and the base of the inner compacting chamber may be spaced apart from the base of the outer framework by a distance of between 180 and 300mm. The at least one pusher plate may be moveable by means of a scissor mechanism and / or a hydraulic ram. The scissor mechanism may comprise at least one pair of scissor arms associated with the or each pusher plate, the scissor arms being pivotably connected to each other. The scissor arms may be pivotably connected to each other at a midpoint of each scissor arm. A first end of one of the scissor arms may be pivotably mounted to the pusher plate and a second end thereof may be slidably mounted to the outer framework, and a first end of the other of the scissor arms may be slidably mounted to the pusher plate and a second end thereof may be pivotably mounted to the outer framework. At least one of the outer frame work and the inner compacting chamber may be provided with a door. The door may be provided with a loading opening. The loading opening may be provided with a closing member. The pusher plate of the waste ejection assembly may be arranged substantially perpendicular to the press plate of the compaction plate assembly. A further aspect of the invention provides a method for compacting waste using the waste compacting apparatus as hereinbefore defined, the method comprising the steps of: a) introducing waste into the inner compacting chamber of the apparatus; b) compacting the waste within the inner compacting chamber by actuating the compaction plate assembly and causing the press plate to move from a retracted position downwards within the inner compacting chamber; and c) returning the press plate to the retracted position. The method may comprise the further steps of: d) introducing further waste into the inner compacting chamber; and e) repeating steps b) and c) until the inner compacting chamber is full. The method may comprise the further steps of: (f) introducing an empty roll cage into the outer framework of the apparatus such that the inner compacting chamber is contained within the roll cage; and (g) actuating the waste ejection assembly and causing the at least one pusher plate to push compacted waste out of the inner compacting chamber and into the roll cage, causing the roll cage filled with compacted waste to be pushed out of the apparatus; and (h) returning the at least one pusher plate to a retracted position Brief Description of the Drawings In the drawings, which illustrate preferred embodiments of the waste compacting apparatus of the invention and are by way of example: Figure 1 illustrates a perspective view of a waste compacting apparatus, shown with main door open; Figure 2 illustrates the apparatus of Figure 1, shown with main door closed and loading door open; Figure 3 is a plan view of the apparatus of Figure 1 with the main door and loading door closed; Figure 4 is a rear view of the apparatus of Figure 1; Figure 5 is a simplified side view of the apparatus of Figure 1, shown with the compaction press plate lowered; Figure 6 is a perspective view of the waste compacting apparatus of Figure 1, shown with the ejection pusher plates in an extended configuration; Figure 7 is a simplified side view of the waste compacting apparatus of Figure 6, with an inner compacting chamber wall removed for clarity; Figure 8 is a simplified side view of the waste compacting apparatus of Figure 1, showing the ejection pusher plates in a retracted configuration; Figure 9 is a simplified perspective view of the apparatus illustrating the scissor mechanism at the rear of the pusher plates; Figure 10 is a simplified perspective view of the apparatus illustrating the scissor mechanism at the rear of the outer framework; Figure 11 illustrates the apparatus of Figure 1 with a roll cage surrounding the inner compacting chamber; Figure 12 illustrates the ejection of a roll cage filled with compacted waste from the apparatus; Figure 13a is a partial schematic view of the apparatus of Figure 1, illustrating the compaction plate assembly; and Figure 13b illustrates a simplified plan view of the apparatus of Figure 1, illustrating the compaction plate assembly. Detailed Description of the Preferred Embodiments Referring now to Figure 1, a waste compacting apparatus is shown generally at 10 and comprises an outer frame 1, including at least four vertical members 2, and horizontal members 3, 3 ’joining the vertical frame members. The outer frame 1 may include side wall members 4 which each extend between two of the vertical members. The side wall members 4 may cover the entire side walls of the outer frame. As shown in Figure 2, the front of the frame is provided with a hinged door member 5, which includes an opening 13 provided with a closing member in the form of a loading door 6. At floor level, the front of the frame does not include a horizontal frame member. This is so that there is no obstruction at the floor level and so that a roll cage can be easily rolled into and out of the outer frame. Inside the outer frame there is provided an inner compaction chamber 7. The inner compaction chamber comprises a pair of side walls 8, 8 ’mounted on a base 9. As illustrated in Figure 1, the base 9 of the inner chamber is raised a distance X above the floor, providing a gap 11 underneath the base of the inner chamber. The side walls are also spaced apart a distance Y, Y ’ from the sides of the outer frame, providing a gap 12 to either side of the inner compaction chamber. The side walls and base of the inner compaction chamber are fixedly attached to the outer frame. When the main door 5 is closed, this door abuts the front edges of the side walls of the inner chamber and the door forms at least part of the front side of the inner compaction chamber. The loading door 6 allows waste to be introduced into the inner chamber through the opening 13, as illustrated in Figure 2. A compaction plate assembly includes a substantially horizontally press plate 14 mounted on a substantially vertical arm 16. The arm 16 is connected to a plurality of sliding members 17 (best shown in Figures 13a and 13b) which are arranged to slide up and down within vertical channels 18. The vertical channels 18 are attached to the rear of the outer frame. A hydraulic ram 19 is positioned centrally at the rear of the outer frame 1, in between the vertical channels 18, and aligned with the vertical arm 16 of the compaction plate assembly. The compaction plate assembly is fixed to the piston 21 of the hydraulic ram 19, preferably via a bolted connection indicated at numeral 20. As the piston of the hydraulic ram extends vertically downwards, the sliding members 17 of the compaction plate assembly, along with the press plate 14 are also urged downwards. The stroke of the hydraulic ram is approximately Im. When the piston 21 of the hydraulic ram 19 is in an unextended position the press plate 14 rests towards the top of the inner chamber as shown in Figures 1 and 2. Figure 5 illustrates the position of the press plate 14 with the arm of the hydraulic ram fully extended. In the simplified side view of Figure 5, one of the inner chamber side walls 8 ’ has been removed for clarity. A mechanism for ejecting compacted waste from the apparatus comprises a pair of pusher plates 15,15 ’which are located at the rear of the inner chamber, towards the rear of the outer frame. A single pusher plate could also be used. The pusher plates 15, 15 ’each preferably extend longitudinally along the full height of the inner compaction chamber. In the illustrated example each pusher plate is mounted on a scissor mechanism which serves to retract the pusher plates 15, 15’ to the rear of the inner chamber 7, or to urge the pusher plates forwards. In Figure 1 the pusher plates are in the retracted position, and in Figure 6, the pusher plates 15, 15’ are shown in the extended position. The scissor mechanism is best illustrated in Figures 7 to 10. Each pusher plate 15,15’ is provided with a pair of scissor arms 22,24 connected together at a midpoint such that they may pivot with respect to one another. In the illustrated example, each scissor arm is in the form of a pair of parallel members which are connected together via bracing elements 32. With reference to the first pusher plate 15, a first scissor arm 22 is pivotably connected to a second scissor arm 24 at a midpoint 27. The first scissor arm 22 is pivotably mounted towards the rear of the outer frame at a first end 23, and is slidably mounted to the pusher plate 15 at a second end 25. The slide mounting is better illustrated in Figure 9 and comprises a sliding member 33 fixed to the second end 25 of the first scissor arm 22 such that the sliding member 33 may pivot with respect to the first scissor arm 22. The sliding member is located within a channel 31, such that the sliding member 33 can slide up and down within the channel 31. The second scissor arm 24 is pivotably mounted to the bottom of the pusher plate 15 at a first end 26, and slidably mounted to the rear of the outer frame at a second end 30. The slide mounting is better illustrated in Figure 10 and comprises a sliding member 34 fixed to the second end 30 of the second scissor arm 24 such that the sliding member 34 may pivot with respect to the second scissor arm 24. The sliding member is located within a channel 35, such that the sliding member 34 can slide up and down within the channel 35. The scissor arm assembly for the second pusher plate 15 ’is identical, and reference numerals have a prime suffix added. Each of the scissor arm assemblies includes a hydraulic ram 28, 28 ’which is pivotably mounted to the rear of the outer frame. The piston 29,29 ’of each hydraulic ram 28,28’ is pivotably mounted to the respective second scissor arm 24, 24’ at a location in between the midpoint 27, 27 ’ and the first end 26, 26’ of the second scissor arm. The hydraulic rams 28, 28 ’are actuated simultaneously to move both pusher plates 15,15 ’at substantially the same rate. The hydraulic rams 28,28’ may be provided with a flow equalization valve to equalise the flow of hydraulic fluid to each ram. The ejection assembly could equally comprise a single or double hydraulic ram without the scissor mechanism. To use the apparatus, the main door 5 is closed, the press plate 14 is raised and the pusher plates 15, 15 ’are retracted to the rear of the inner compaction chamber. The loading door 6 is opened and an operator can introduce loose waste into the inner compaction chamber 7 through the opening 13. When the inner compaction chamber 7 is full of loose waste the loading door 6 is closed and the compaction mechanism is operated. The press plate 14 is urged downwards by the hydraulic ram 19, compacting the waste below it. The press plate 14 is then returned to its rest position at the top of the inner chamber 7. Further loose waste can now be introduced into the inner compaction chamber 7 via the loading door 6, and the compaction process can then be repeated. This process of loading and compaction continues until the inner compaction chamber 7 is full of compacted waste 37. Preferably the apparatus includes sensors which alert an operator when the inner compaction chamber 7 is full, such an alert may include a light on the exterior of the apparatus. To empty the inner compaction chamber 7 the operator opens the main door 5 and pushes an empty roll cage 36 into the outer framework. As shown in Figure 11, the inner compaction chamber 7 is positioned such that the whole of the inner compaction chamber 7 locates within the interior of the roll cage. The roll cage walls locate within the gap 12, 12 ’to the sides of the inner chamber side walls 8, 8’; and the roll cage floor and wheels locate within the gap 11 underneath the base 9 of the inner chamber. For example, the base of the inner chamber may be spaced apart from the floor at distance of approximately 200mm, and the sides of the inner chamber may be spaced apart by distance of approximately 600mm. This allows the inner chamber to fit comfortably within the internal space of a roll cage with an internal width of approximately 750mm and base height of approximately 180mm from the floor. Activation of the ejection mechanism allows the pusher plates 15, 15 ’to push the compacted waste 21 out of the inner compaction chamber 7. Since the roll cage 36 is on wheels, the presser plates 15, 15 ’push the waste and cage 36 out of the apparatus together, until the roll cage, complete with compacted waste 37 is ejected from the apparatus, as illustrated in Figure 12. The roll cage filled with compacted waste 37 can then be easily rolled away from the compacter apparatus and stored until it is collected for recycling or other disposal. No other manual handling of the bale of compacted waste is required. The main door 5 can then be closed and fresh loose waste introduced via the loading door 6. The apparatus of the invention allows a large force, typically in excess of 3 tonnes, to be exerted on the waste material within the inner compaction chamber. This means that one roll cage full of waste compacted using the apparatus of the invention is equivalent to six or seven roll cages full of loose waste material, leading to large savings in transport costs. Empty roll cages can be easily stacked together for transport, meaning fewer trucks are required to transport the combination of empty cages and waste.

Claims

1. A waste compacting apparatus comprising:an outer framework;an inner compacting chamber;a compaction plate assembly; anda waste ejection assembly for ejecting compacted waste from the apparatus;wherein the inner compacting chamber comprises a pair of spaced apart side walls and a base, wherein the side walls and base are fixedly attached to the outer framework;and wherein the inner compacting chamber is positioned such that the side walls and the base of the inner compacting chamber locate within an interior space of a roll cage when a roll cage is introduced into the framework;and wherein the compaction plate assembly includes a press plate which is moveable between an upper position and a lower position within the inner compacting chamber such that waste within the inner compacting chamber is compacted by the press plate;and wherein the waste ejection assembly comprises at least one pusher plate configured to move between a retracted position located at a rear region of the inner compaction chamber, and an extended position located at a front region of the inner compaction chamber.

2. A waste compacting apparatus according to Claim 1, wherein the press plate is moveable by means of a hydraulic ram.

3. A waste compacting apparatus according to Claim 1 or 2, wherein the outer framework supports side walls spaced apart from the side walls of the inner compacting chamber.

4. A waste compacting apparatus according to Claim 3, wherein the side walls of the inner compacting chamber are spaced apart from the side walls of the outer framework by a distance of between 150 and 300mm.

5. A waste compacting apparatus according to any preceding claim, wherein the outer framework comprises a base and the base of the inner compacting chamber is spaced apart from the base of the outer framework by a distance of between 180 and 300mm.

6. A waste compacting apparatus according to any preceding claim, wherein the at least one pusher plate is moveable by means of a scissor mechanism and / or a hydraulic ram.

7. A waste compacting apparatus according to Claim 6, wherein the scissor mechanism comprises at least one pair of scissor arms associated with the or each pusher plate, the scissor arms being pivotably connected to each other.

8. A waste compacting apparatus according to Claim 7, wherein the scissor arms being pivotably connected to each other at a midpoint of each scissor arm.

9. A waste compacting apparatus according to Claim 7 or 8, wherein a first end of one of the scissor arms is pivotably mounted to the pusher plate and a second end thereof is slidably mounted to outer framework and a first end of the other of the scissor arms is slidably mounted to the pusher plate and a second end thereof is pivotably mounted to outer framework.

10. A waste compacting apparatus according to any preceding claim, wherein at least one of the outer framework and the inner compacting chamber is provided with a door.

11. A waste compacting apparatus according to Claim 10, wherein the door is provided with a loading opening.

12. A waste compacting apparatus according to Claim 11, wherein the loading opening is provided with a closing member.

13. A waste compacting apparatus according to any preceding claim, wherein the pusher plate of the waste ejection assembly is arranged substantially perpendicular to the press plate of the compaction plate assembly.

14. A method for compacting waste using the apparatus of claims 1 to 13 comprising the steps of:a) introducing waste into the inner compacting chamber of the apparatus;b) compacting the waste within the inner compacting chamber by actuating the compaction plate assembly and causing the press plate to move from a retracted position downwardswithin the inner compacting chamber; andc) returning the press plate to the retracted position.

15. A method for compacting waste according to Claim 14, comprising the further steps of:d) introducing further waste into the inner compacting chamber; ande) repeating steps b) and c) until the inner compacting chamber is full.

16. A method for compacting waste according to Claim 15 comprising the further steps of:(f) introducing an empty roll cage into the outer framework of the apparatus such that the inner compacting chamber is contained within the roll cage; and(g) actuating the waste ejection assembly and causing the at least one pusher plate to push compacted waste out of the inner compacting chamber and into the roll cage, causing the roll cage filled with compacted waste to be pushed out of the apparatus; and(h) returning the at least one pusher plate to a retracted position.

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