GB2455544A - Waste Compactor - Google Patents

Abstract

The waste compactor 10 comprises a housing defining a waste compaction region 18 in which waste is compacted disposed above a compacted waste receiving space 40. The waste compactor 10 also comprises two opposed substantially parallel press plates 27, 28 disposed within the compaction region 18, which are moveable by power drive means towards and away from each other along a common axis. A trapdoor 23 separates the compaction region 18 from the receiving space 40, and the trapdoor 20 is moveable between a closed position for waste compaction and an open position for depositing compacted waste in the receiving space 40. The trapdoor includes an operating mechanism arranged to move the trapdoor 23 to the open position when the press plates 27, 28 have been moved closer than a predetermined spacing and also to move the trapdoor 23 to the closed position when the press plates 27, 26 have been moved apart after compacting waste.

Description

WASTE COMPACTOR

The present invention relates to a waste compactor and in particular, but not exclusively, to a waste compactor suitable for use in compacting waste domestic containers, cartons, packaging and the like.

Domestic waste compactors are used to break up and compact various emptied containers and packaging materials, including containers of paper, plastics and glass, in order that the used containers can be stored and transported for recycling or disposal without wasting space. Compactors for use in a domestic environment are known, but mostly they suffer from several drawbacks, which have prevented their widespread use.

EPI 745921 shows an example of one such domestic waste compactor.

This compactor has a press plate operated by a lazy tong arrangement, positioned above a container storing waste. The ram is arranged to force the press plate down into the container to crush the waste. This arrangement has the drawback that only a limited force can be exerted onto the waste without damaging the container.

The present invention aims at providing a domestic waste compactor that is capable of producing a high compressive force within a limited volume. Therefore, according to the present invention there is provided a domestic waste compactor comprising: -a housing defining a waste compaction region in which waste is compacted and a compacted waste receiving space, the compaction region being disposed above the receiving space; -two opposed substantially parallel press plates disposed within the compaction region, the press plates being moveable towards and away from each other along a common axis; -power drive means to move the press plates along said axis; -a trapdoor separating the compaction region from the receiving space, the trapdoor being moveable between a closed position for waste compaction and an open position for depositing compacted waste in the receMng space; and -a trapdoor operating mechanism arranged to move the trapdoor to the open position when the press plates have been moved closer than a predetermined spacing and to move the trapdoor to the closed position when the press plates have been moved apart after compacting waste.

Waste to be compacted is inserted into the waste compaction region and then the press plates are driven closer together. Once compacted, the waste is released by opening the trapdoor, allowing the waste to fall into the receiving space for subsequent removal. The power drive means should be sufficiently powerful to compact the waste so that the press plates move closer than a predetermined spacing, for the trapdoor operating mechanism to effect opening of the trapdoor. Subsequently the plates being returned to their initial, furthest-apart position closes the trapdoor.

Preferably, the power drive means comprises hydraulic rams together with an electric motor-driven hydraulic pump and control gear. Conveniently, each plate has a single hydraulic ram associated therewith, disposed to act centrally on the plate. The two press plates are forced towards the centre of the compaction region by the hydraulic rams to compact any waste therebetween. Alternatively, and particularly on large waste compactors, each plate may have two or more rams associated therewith.

To enable control of the applied compacting force, the rams are preferably provided with pressure sensors. The press plates preferably converge until a certain pressure threshold is reached, and a switch causes the press plates to return to their initial furthest-apart position. Preferably, further pressure sensors detect that the press plates have reached their furthest-apart position, and the waste compactor ceases operation. Preferably the pressure thresholds on the sensors are adjustable.

The present invention incorporates an operating mechanism to open and close the trapdoor with the action of the press plates. In a preferred embodiment a single trapdoor is provided which is hinged beneath the compaction region. For a preferred operating mechanism the trapdoor is hinged to the bottom of one of the press plates. When released the trapdoor opens about the hinge and the contents of the compacting region fall into the receiving space.

To hold the trapdoor shut when required, the operating mechanism preferably includes a trapdoor support positioned beneath the trapdoor. When the press plates are furthest apart, the trapdoor support holds the trapdoor shut. The trapdoor support is positioned so that when the press plates converge closer than a predetermined spacing, the hinge attaching the trapdoor to the press plate passes said trapdoor support, and the trapdoor opens. As the press plates are returned to their furthest-apart position, the trapdoor engages with the trapdoor support and is closed by the movement of the press plate. Preferably, the trapdoor support is a bar arranged substantially parallel with the bottom of the press plate to which the trapdoor is hinged.

One or more rollers are preferably provided beneath the trapdoor to provide further support and to facilitate movement of the trapdoor when the press plates are converging. The rollers preferably only support the edge regions of the trapdoor. The trapdoor is preferably provided with one or more notches on either or both side edges thereof, the notch or notches being positioned to permit the trapdoor to fall past the or each roller once the press plates have reached the predetermined position. The or each roller preferably supports the trapdoor until the or each notch reaches the or each roller, whereupon the trapdoor is no longer supported thereby, and the trapdoor opens. Ideally, ones or more further notches are also provided on the edges of the trapdoor towards the end furthest from the hinges. These further notches permit the trapdoor to pass back over the roller(s) as the trapdoor moves to the closed position. Of course, alternative means may be employed to operate the opening and closing of the trapdoor, such as a catch and release mechanism.

The compaction region is preferably substantially cuboidal, comprising two fixed side walls between which the press plates slide. A lid may be provided for the compaction region, and the trapdoor is arranged below said compaction region.

Each hydraulic ram is preferably disposed towards the centre of each press plate, with the compacting surface of the press plate being substantially perpendicular to the ram. To prevent the force from the compaction of the waste causing the press plates to rotate about the end of each ram, the position of each press plate is preferably maintained by one, but preferably two guide rods. To further reduce rotation of the press plates about the end of each ram, each press plate is preferably provided with guide pins. A guide pin is preferably mounted towards the top and bottom of at least one side of each press plate, the guide pins extending through parallel grooves or slots in the side walls of the compacting region.

The present invention is suitable for use in compacting any domestic waste containers, including glass and plastic bottles, tin cans and cardboard boxes.

Plastic bottles, if not cut up or punctured, have a tendency to return to their previous shape once crushed. Therefore it is preferred that crushing blades are attached to the compacting surface of the two press plates, which will break up the bottles and prevent the problem herein described.

During use the crushing blades may become worn or broken, so it is preferred that the blades are replaceable. The crushing surface is preferably provided with grooves into which the blades locate, although any suitable alternative means of replacing the crushing blades is within the scope of the present invention.

Once compacted, the waste will drop from the compaction region into the receMng space. The term "receiving space" as used herein refers to the space beneath the compacting region. In one embodiment the receiving space may be a discrete section beneath the compacting region with side walls and a door to access the inside thereof. If provided, the door may have a safety switch so that the waste compactor will not operate if said door is open. Preferably, a removable container is provided in the receiving space to collect the compacted waste.

The compacting region preferably has an inlet, and a lid preferably covers the inlet. For reasons of safety it is preferred that the lid has a lock so the press plates cannot be operated unless the lid is locked. Alternatively, the lid may be provided with a magnetic switch, so that the waste compactor operates automatically once the lid has been closed, and will not operate if the lid is opened.

So that the invention may be better understood, one embodiment of domestic waste compactor will now be described in detail, by way of example only with reference to the following drawings in which: Figure 1 shows a cross sectional side view of a waste compactor in a closed position; Figure 2 shows a cross sectional side view of the waste compactor in an open position; FIgure 3 shows a cross sectional top view of the compaction region of the waste compactor; FIgure 4 shows a cross sectional bottom view of the compaction region of the waste compactor; FIgure 5 shows a front view of the waste compactor and Figure 6 shows a top view of the press plates and the crushing blades.

Refening to the drawings, there is shown a waste compactor generally indicated 10. The waste compactor has a housing, which comprises front wall 12, rear wall 13, side walls 14, 15, base 16 and roof 17. The waste compactor 10 is divided into a waste compaction region 18, in which domestic waste containers such as cans and bottles are compacted, and a waste receiving space 40 into which the waste is deposited once compacted. The compaction region 18 is the space between internal front wall 19, internal rear wall 20, and press plates 27, 28.

The press plates 27, 28 are arranged parallel to internal side walls 21, 22. A lid is provided, which comprises two panels 25 and 26, which are slidably attached to said roof 17. The compaction region 18 and the receiving space 40 are separated by trapdoor 23, which is hinged to the bottom of press plate 28. The panels 25, 26 are slid apart to open the lid and allow waste to be inserted into the waste compaction region 18. A magnetic switch (not shown) is provided in panels 25, 26 to operate the waste compactor 10 when the panels 25,26 are closed together.

The press plates 27, 28 in use compact waste placed into the compaction region 18. The press plates 27, 28 are operated by hydraulic rams 29, 30 respectively. The hydraulic rams 29, 30 are powered by pump 31, which is connected to the rams 29, 30 via pipes 32, 33 respectively. As shown in Figure 5, removable crushing blades 36 are mounted in each press plate 27, 28. These crushing blades 36 break up waste containers such as plastic bottles, and may be replaced if broken by sliding them out of the press plates 27, 28. Pressure sensors are provided on the hydraulic rams 29, 30. The press plates 27, 28 converge until a certain pressure threshold is reached, and then return to the furthest apart position. Once this position is reached, further pressure sensors activate a switch to cease the motion of the press plates 27, 28.

Guide rods 34 are positioned either side of hydraulic rams 29, 30. These guide rods 34 are telescopically mounted in sleeves 35, and are attached to the press plates 27, 28. The guide rods 34 prevent rotation of the press plates 27, 28 relative to the ends of the rams 29, 30 when compacting waste. To further stabilise the press plates 27, 28, pins 49 extend from the top and bottom of the side face of the press plates 27, 28 out through parallel slots (not shown) in the internal front wall 19 and internal rear wall 20 to prevent said press plates 27, 28 rotating about the ends of the rams 29, 30.

The trapdoor 23 is connected to the base of press plate 28 by hinges 50.

The trapdoor 23 is configured to remain closed whilst the press plates 27, 28 are compacting waste, but to open once the press plates 27, 28 have moved to a predetermined position. The trapdoor 23 opens and the compacted waste is deposited into the receiving space 40. Mechanisms are employed to control the opening and closing of the trapdoor 23 at the correct moment Specifically, a bar 51 is provided between the internal front wall 19 and internal rear wall 20. As shown in Figure 1, the bar 51 is positioned just beneath the trapdoor 23, which is held shut by said bar 51, and in front of press plate 28 when the press plates 27, 28 are furthest apart. The trapdoor 23 is further supported by rollers 52 attached to the internal front wall 19 and the internal rear wall 20. When the press plates 27, 28 converge towards the centre of the compaction region 18, the trapdoor 23 is supported by, and moves across, the rollers 52.

Rear notches 53 are provided on the trapdoor 23, and these are slightly larger than the rollers 52. When the pres plates 27, 28 converge towards the centre of the compaction region 18, the rear notches 53 then pass over the rollers 52 and the trapdoor 23 opens. When the press plates 27, 28 separate and return to their initial furthest-apart position, press plate 28 passes bar 51. When this happens, the trapdoor 23 hits the bar 51 and is closed. Forward notches 54 are provided at the side edges of the trapdoor furthest away from the hinges 50. The forward notches are also slightly larger than the rollers 52, so when the trapdoor 23 is closed said forward notches 54 pass over said rollers 52.

The receiving space 40 comprises the area beneath the trapdoor 23 and between front wall 12, rear wall 13, side walls 14 15, and internal base 41. Also within the receiving space are runners 42 for receiving a removable container (not shown). The receiving space 40 can be accessed via the transparent concertina doors 44, as shown in Figure 4. The concertina doors 44 are provided with a switch (not shown), which prevents operation of the waste compactor 10 if said door 44 are open.

Waste can be inserted into the waste compactor 10 when said waste compactor is configured as shown in Figure 1. Panels 25, 26 are slid underneath roof 17 and the waste compaction region 18 is exposed. The press plates 27, 28 are fully retracted and the trapdoor 23 is closed. Waste is inserted into the compaction region 18 and as soon as panels 25, 26 are slid shut the magnetic switch is switched on. The compacting process then begins, whereby the press plates 27, 28 move towards the centre of the compaction region 18, driven by hydraulic rams 29, 30. When the press 27, 28 plates reach a predetermined position within the waste compaction region 18, the rear notches 53 on the trapdoor 23 pass over the rollers 52 and the trapdoor 23 opens. Separately, when a certain compacting pressure threshold is passed the press plates 27, 28 return to their furthest apart position. As this happens the waste falls into the receiving space 40. The trapdoor 23 shuts as the hinges 50 on the base of press plate 28 passes bar 51, and the forward notches 54 pass the rollers 52. The operation of the waste compactor 10 ceases when the pressure sensors in the hydraulic rams 29, 30 detect that the press plates 27, 28 have returned to their furthest apart position. The waste compactor 10 may then be used again. -11 - WASTE COMPACTOR

The present invention relates to a waste compactor and in particular, but not exclusively, to a waste compactor suitable for use in compacting waste domestic containers, cartons, packaging and the like.

Domestic waste compactors are used to break up and compact various emptied containers and packaging materials, including containers of paper, plastics and glass, in order that the used containers can be stored and transported for recycling or disposal without wasting space. Compactors for use in a domestic environment are known, but mostly they suffer from several drawbacks, which have prevented their widespread use.

EPI 745921 shows an example of one such domestic waste compactor.

This compactor has a press plate operated by a lazy tong arrangement, positioned above a container storing waste. The ram is arranged to force the press plate down into the container to crush the waste. This arrangement has the drawback that only a limited force can be exerted onto the waste without damaging the container.

The present invention aims at providing a domestic waste compactor that is capable of producing a high compressive force within a limited volume. Therefore, according to the present invention there is provided a domestic waste compactor comprising: -a housing defining a waste compaction region in which waste is compacted and a compacted waste receiving space, the compaction region being disposed above the receiving space; -two opposed substantially parallel press plates disposed within the compaction region, the press plates being moveable towards and away from each other along a common axis; -power drive means to move the press plates along said axis; -a trapdoor separating the compaction region from the receiving space, the trapdoor being moveable between a closed position for waste compaction and an open position for depositing compacted waste in the receMng space; and -a trapdoor operating mechanism arranged to move the trapdoor to the open position when the press plates have been moved closer than a predetermined spacing and to move the trapdoor to the closed position when the press plates have been moved apart after compacting waste.

Waste to be compacted is inserted into the waste compaction region and then the press plates are driven closer together. Once compacted, the waste is released by opening the trapdoor, allowing the waste to fall into the receiving space for subsequent removal. The power drive means should be sufficiently powerful to compact the waste so that the press plates move closer than a predetermined spacing, for the trapdoor operating mechanism to effect opening of the trapdoor. Subsequently the plates being returned to their initial, furthest-apart position closes the trapdoor.

Preferably, the power drive means comprises hydraulic rams together with an electric motor-driven hydraulic pump and control gear. Conveniently, each plate has a single hydraulic ram associated therewith, disposed to act centrally on the plate. The two press plates are forced towards the centre of the compaction region by the hydraulic rams to compact any waste therebetween. Alternatively, and particularly on large waste compactors, each plate may have two or more rams associated therewith.

To enable control of the applied compacting force, the rams are preferably provided with pressure sensors. The press plates preferably converge until a certain pressure threshold is reached, and a switch causes the press plates to return to their initial furthest-apart position. Preferably, further pressure sensors detect that the press plates have reached their furthest-apart position, and the waste compactor ceases operation. Preferably the pressure thresholds on the sensors are adjustable.

The present invention incorporates an operating mechanism to open and close the trapdoor with the action of the press plates. In a preferred embodiment a single trapdoor is provided which is hinged beneath the compaction region. For a preferred operating mechanism the trapdoor is hinged to the bottom of one of the press plates. When released the trapdoor opens about the hinge and the contents of the compacting region fall into the receiving space.

To hold the trapdoor shut when required, the operating mechanism preferably includes a trapdoor support positioned beneath the trapdoor. When the press plates are furthest apart, the trapdoor support holds the trapdoor shut. The trapdoor support is positioned so that when the press plates converge closer than a predetermined spacing, the hinge attaching the trapdoor to the press plate passes said trapdoor support, and the trapdoor opens. As the press plates are returned to their furthest-apart position, the trapdoor engages with the trapdoor support and is closed by the movement of the press plate. Preferably, the trapdoor support is a bar arranged substantially parallel with the bottom of the press plate to which the trapdoor is hinged.

One or more rollers are preferably provided beneath the trapdoor to provide further support and to facilitate movement of the trapdoor when the press plates are converging. The rollers preferably only support the edge regions of the trapdoor. The trapdoor is preferably provided with one or more notches on either or both side edges thereof, the notch or notches being positioned to permit the trapdoor to fall past the or each roller once the press plates have reached the predetermined position. The or each roller preferably supports the trapdoor until the or each notch reaches the or each roller, whereupon the trapdoor is no longer supported thereby, and the trapdoor opens. Ideally, ones or more further notches are also provided on the edges of the trapdoor towards the end furthest from the hinges. These further notches permit the trapdoor to pass back over the roller(s) as the trapdoor moves to the closed position. Of course, alternative means may be employed to operate the opening and closing of the trapdoor, such as a catch and release mechanism.

The compaction region is preferably substantially cuboidal, comprising two fixed side walls between which the press plates slide. A lid may be provided for the compaction region, and the trapdoor is arranged below said compaction region.

Each hydraulic ram is preferably disposed towards the centre of each press plate, with the compacting surface of the press plate being substantially perpendicular to the ram. To prevent the force from the compaction of the waste causing the press plates to rotate about the end of each ram, the position of each press plate is preferably maintained by one, but preferably two guide rods. To further reduce rotation of the press plates about the end of each ram, each press plate is preferably provided with guide pins. A guide pin is preferably mounted towards the top and bottom of at least one side of each press plate, the guide pins extending through parallel grooves or slots in the side walls of the compacting region.

The present invention is suitable for use in compacting any domestic waste containers, including glass and plastic bottles, tin cans and cardboard boxes.

Plastic bottles, if not cut up or punctured, have a tendency to return to their previous shape once crushed. Therefore it is preferred that crushing blades are attached to the compacting surface of the two press plates, which will break up the bottles and prevent the problem herein described.

During use the crushing blades may become worn or broken, so it is preferred that the blades are replaceable. The crushing surface is preferably provided with grooves into which the blades locate, although any suitable alternative means of replacing the crushing blades is within the scope of the present invention.

Once compacted, the waste will drop from the compaction region into the receMng space. The term "receiving space" as used herein refers to the space beneath the compacting region. In one embodiment the receiving space may be a discrete section beneath the compacting region with side walls and a door to access the inside thereof. If provided, the door may have a safety switch so that the waste compactor will not operate if said door is open. Preferably, a removable container is provided in the receiving space to collect the compacted waste.

The compacting region preferably has an inlet, and a lid preferably covers the inlet. For reasons of safety it is preferred that the lid has a lock so the press plates cannot be operated unless the lid is locked. Alternatively, the lid may be provided with a magnetic switch, so that the waste compactor operates automatically once the lid has been closed, and will not operate if the lid is opened.

So that the invention may be better understood, one embodiment of domestic waste compactor will now be described in detail, by way of example only with reference to the following drawings in which: Figure 1 shows a cross sectional side view of a waste compactor in a closed position; Figure 2 shows a cross sectional side view of the waste compactor in an open position; FIgure 3 shows a cross sectional top view of the compaction region of the waste compactor; FIgure 4 shows a cross sectional bottom view of the compaction region of the waste compactor; FIgure 5 shows a front view of the waste compactor and Figure 6 shows a top view of the press plates and the crushing blades.

Refening to the drawings, there is shown a waste compactor generally indicated 10. The waste compactor has a housing, which comprises front wall 12, rear wall 13, side walls 14, 15, base 16 and roof 17. The waste compactor 10 is divided into a waste compaction region 18, in which domestic waste containers such as cans and bottles are compacted, and a waste receiving space 40 into which the waste is deposited once compacted. The compaction region 18 is the space between internal front wall 19, internal rear wall 20, and press plates 27, 28.

The press plates 27, 28 are arranged parallel to internal side walls 21, 22. A lid is provided, which comprises two panels 25 and 26, which are slidably attached to said roof 17. The compaction region 18 and the receiving space 40 are separated by trapdoor 23, which is hinged to the bottom of press plate 28. The panels 25, 26 are slid apart to open the lid and allow waste to be inserted into the waste compaction region 18. A magnetic switch (not shown) is provided in panels 25, 26 to operate the waste compactor 10 when the panels 25,26 are closed together.

The press plates 27, 28 in use compact waste placed into the compaction region 18. The press plates 27, 28 are operated by hydraulic rams 29, 30 respectively. The hydraulic rams 29, 30 are powered by pump 31, which is connected to the rams 29, 30 via pipes 32, 33 respectively. As shown in Figure 5, removable crushing blades 36 are mounted in each press plate 27, 28. These crushing blades 36 break up waste containers such as plastic bottles, and may be replaced if broken by sliding them out of the press plates 27, 28. Pressure sensors are provided on the hydraulic rams 29, 30. The press plates 27, 28 converge until a certain pressure threshold is reached, and then return to the furthest apart position. Once this position is reached, further pressure sensors activate a switch to cease the motion of the press plates 27, 28.

Guide rods 34 are positioned either side of hydraulic rams 29, 30. These guide rods 34 are telescopically mounted in sleeves 35, and are attached to the press plates 27, 28. The guide rods 34 prevent rotation of the press plates 27, 28 relative to the ends of the rams 29, 30 when compacting waste. To further stabilise the press plates 27, 28, pins 49 extend from the top and bottom of the side face of the press plates 27, 28 out through parallel slots (not shown) in the internal front wall 19 and internal rear wall 20 to prevent said press plates 27, 28 rotating about the ends of the rams 29, 30.

The trapdoor 23 is connected to the base of press plate 28 by hinges 50.

The trapdoor 23 is configured to remain closed whilst the press plates 27, 28 are compacting waste, but to open once the press plates 27, 28 have moved to a predetermined position. The trapdoor 23 opens and the compacted waste is deposited into the receiving space 40. Mechanisms are employed to control the opening and closing of the trapdoor 23 at the correct moment Specifically, a bar 51 is provided between the internal front wall 19 and internal rear wall 20. As shown in Figure 1, the bar 51 is positioned just beneath the trapdoor 23, which is held shut by said bar 51, and in front of press plate 28 when the press plates 27, 28 are furthest apart. The trapdoor 23 is further supported by rollers 52 attached to the internal front wall 19 and the internal rear wall 20. When the press plates 27, 28 converge towards the centre of the compaction region 18, the trapdoor 23 is supported by, and moves across, the rollers 52.

Rear notches 53 are provided on the trapdoor 23, and these are slightly larger than the rollers 52. When the pres plates 27, 28 converge towards the centre of the compaction region 18, the rear notches 53 then pass over the rollers 52 and the trapdoor 23 opens. When the press plates 27, 28 separate and return to their initial furthest-apart position, press plate 28 passes bar 51. When this happens, the trapdoor 23 hits the bar 51 and is closed. Forward notches 54 are provided at the side edges of the trapdoor furthest away from the hinges 50. The forward notches are also slightly larger than the rollers 52, so when the trapdoor 23 is closed said forward notches 54 pass over said rollers 52.

The receiving space 40 comprises the area beneath the trapdoor 23 and between front wall 12, rear wall 13, side walls 14 15, and internal base 41. Also within the receiving space are runners 42 for receiving a removable container (not shown). The receiving space 40 can be accessed via the transparent concertina doors 44, as shown in Figure 4. The concertina doors 44 are provided with a switch (not shown), which prevents operation of the waste compactor 10 if said door 44 are open.

Waste can be inserted into the waste compactor 10 when said waste compactor is configured as shown in Figure 1. Panels 25, 26 are slid underneath roof 17 and the waste compaction region 18 is exposed. The press plates 27, 28 are fully retracted and the trapdoor 23 is closed. Waste is inserted into the compaction region 18 and as soon as panels 25, 26 are slid shut the magnetic switch is switched on. The compacting process then begins, whereby the press plates 27, 28 move towards the centre of the compaction region 18, driven by hydraulic rams 29, 30. When the press 27, 28 plates reach a predetermined position within the waste compaction region 18, the rear notches 53 on the trapdoor 23 pass over the rollers 52 and the trapdoor 23 opens. Separately, when a certain compacting pressure threshold is passed the press plates 27, 28 return to their furthest apart position. As this happens the waste falls into the receiving space 40. The trapdoor 23 shuts as the hinges 50 on the base of press plate 28 passes bar 51, and the forward notches 54 pass the rollers 52. The operation of the waste compactor 10 ceases when the pressure sensors in the hydraulic rams 29, 30 detect that the press plates 27, 28 have returned to their furthest apart position. The waste compactor 10 may then be used again. -11 -

Claims (19)

1. A domestic waste compactor comprising: -a housing defining a waste compaction region in which waste is compacted and a compacted waste receiving space, the compaction region being disposed above the receiving space, -two opposed substantially parallel press plates disposed within the compaction region, the press plates being moveable towards and away from each other along a common axis; -power drive means to move the press plates along said axis; -a trapdoor separating the compaction region from the receiving space, the trapdoor being moveable between a closed position for waste compaction and an open position for depositing compacted waste in the receMng space; and -a trapdoor operating mechanism arranged to move the trapdoor to the open position when the press plates have been moved closer than a predetermined spacing and to move the trapdoor to the closed position when the press plates have been moved apart after compacting waste.

2. A domestic waste compactor as claimed in claim 1, wherein the drive means comprises hydraulic rams together with an electric motor-driven pump and control gear.

3. A domestic waste compactor as claimed in claim 2, wherein each press plate has at least one hydraulic ram operable therewith disposed to act centrally on said press plate.

4. A domestic waste compactor as claimed in claim 3, wherein rotation of each press plate about the end of the ram is prevented by one or more guide rod connected to the press plate.

5. A domestic waste compactor as claimed in claim 3 or daim 4, wherein rotation of each press plate about the end of the ram is prevented by one or more guide pin connected to the press plate.

6. A domestic waste compactor as claimed in any of the preceding claims, wherein the trapdoor is hinged to the base of one of the press plates.

7. A domestic waste compactor as claimed in claim 6, wherein the trapdoor is held shut by a support positioned beneath the trapdoor positioned so that when the press plates move closer than a predetermined spacing, the hinges on the trapdoor pass the support and the trapdoor opens.

8. A domestic waste compactor as claimed in claim 7, wherein the support is a bar arranged parallel with the base of the press plate.

9. A domestic waste compactor as claimed in any of any of the preceding claims, wherein the trapdoor is supported on one or more roller.

10. A domestic waste compactor as claimed in claim 9, wherein one or more notches are provided on the side edge of the trapdoor, so when the trapdoor moves to a predetermined position, the notch or notches pass over the rollers and the trapdoor opens.

11. A domestic waste compactor as daimed in any of the preceding claims, wherein pressure sensors are provided, so that the press plates converge until a set pressure threshold is reached, and then a switch causes the press plates to return to a furthest-apart position.

12. A domestic waste compactor as claimed in any of the preceding claims, wherein crushing blades are attached to the surface of each of the two press plates that faces the waste compaction region.

13. A domestic waste compactor as claimed in claim 12, wherein the crushing blades are replaceable.

14. A domestic waste compactor as claimed in daim 12 or claim 13, wherein the crushing blades are locatable within grooves in the surface of the press plates.

15. A domestic waste compactor as claimed in any of the preceding claims, further comprising a removable container in the waste receiving space to collect the compacted waste.

16. A domestic waste compactor as daimed in any of the preceding claims, wherein the waste receiving space has an inlet.

17. A domestic waste compactor as claimed claim 16, wherein the inlet is covered by a lid.

18. A domestic waste compactor as claimed claim 17, wherein the lid includes a magnetic switch so the waste compaction means will not operate unless the lid is locked.

19. A domestic waste compactor as claimed in claim 1 and as substantially herein described with reference to and as illustrated in the accompanying drawings.

19. A domestic waste compactor as claimed in claim 1 and as substantially herein described with reference to and as illustrated in the accompanying drawings.

1. A domestic waste compactor comprising: -a housing defining a waste compaction region in which waste is compacted and a compacted waste receiving space, the compaction region being disposed above the receiving space, -two opposed substantially parallel press plates disposed within the compaction region, the press plates being moveable towards and away from each other along a common axis; -power drive means to move the press plates along said axis; -a trapdoor separating the compaction region from the receiving space, the trapdoor being moveable between a closed position for waste compaction and an open position for depositing compacted waste in the receMng space; and -a trapdoor operating mechanism arranged to move the trapdoor to the open position when the press plates have been moved closer than a predetermined spacing and to move the trapdoor to the closed position when the press plates have been moved apart after compacting waste.

2. A domestic waste compactor as claimed in claim 1, wherein the drive means comprises hydraulic rams together with an electric motor-driven pump and control gear.

3. A domestic waste compactor as claimed in claim 2, wherein each press plate has at least one hydraulic ram operable therewith disposed to act centrally on said press plate.

4. A domestic waste compactor as claimed in claim 3, wherein rotation of each press plate about the end of the ram is prevented by one or more guide rod connected to the press plate.

5. A domestic waste compactor as claimed in claim 3 or daim 4, wherein rotation of each press plate about the end of the ram is prevented by one or more guide pin connected to the press plate.

6. A domestic waste compactor as claimed in any of the preceding claims, wherein the trapdoor is hinged to the base of one of the press plates.

7. A domestic waste compactor as claimed in claim 6, wherein the trapdoor is held shut by a support positioned beneath the trapdoor positioned so that when the press plates move closer than a predetermined spacing, the hinges on the trapdoor pass the support and the trapdoor opens.

8. A domestic waste compactor as claimed in claim 7, wherein the support is a bar arranged parallel with the base of the press plate.

9. A domestic waste compactor as claimed in any of any of the preceding claims, wherein the trapdoor is supported on one or more roller.

10. A domestic waste compactor as claimed in claim 9, wherein one or more notches are provided on the side edge of the trapdoor, so when the trapdoor moves to a predetermined position, the notch or notches pass over the rollers and the trapdoor opens.

11. A domestic waste compactor as daimed in any of the preceding claims, wherein pressure sensors are provided, so that the press plates converge until a set pressure threshold is reached, and then a switch causes the press plates to return to a furthest-apart position.

12. A domestic waste compactor as claimed in any of the preceding claims, wherein crushing blades are attached to the surface of each of the two press plates that faces the waste compaction region.

13. A domestic waste compactor as claimed in claim 12, wherein the crushing blades are replaceable.

14. A domestic waste compactor as claimed in daim 12 or claim 13, wherein the crushing blades are locatable within grooves in the surface of the press plates.

15. A domestic waste compactor as claimed in any of the preceding claims, further comprising a removable container in the waste receiving space to collect the compacted waste.

16. A domestic waste compactor as daimed in any of the preceding claims, wherein the waste receiving space has an inlet.

17. A domestic waste compactor as claimed claim 16, wherein the inlet is covered by a lid.

18. A domestic waste compactor as claimed claim 17, wherein the lid includes a magnetic switch so the waste compaction means will not operate unless the lid is locked.