Compactor, bladed part, carrier, and reverse vending machine

Abstract

Aspects relate to a compactor (200), bladed part (212), carrier (210), and reverse vending machine (100). The compactor (200) comprises a drive shaft (208), a carrier (210) coupled to the drive shaft, and a bladed part (212) releasably mounted to the carrier (210). A further aspect relates to first and second compactors (200A, 200B) having different blade arrangements for their counter-rotatable crusher units (204, 206).

Description

FIELD OF THE INVENTION

[0001] Embodiments of the present invention relate to a compactor, a bladed part for the compactor, a carrier for the compactor, and a reverse vending machine comprising the compactor. In some, but not necessarily all examples, the reverse vending machine is configured to provide aluminium drink cans to a first compactor and plastic drink bottles to a second compactor.BACKGROUND TO THE INVENTION

[0002] Compactors are used in various machines, typically to reduce the volume of waste within a waste stream.

[0003] A reverse vending machine is a vending machine that accepts waste, usually recyclable waste, in exchange for a financial reward or a token. This simultaneously incentivises recycling and disincentivises littering. Reverse vending machines operate automatically and are generally unsupervised, only being accessed by on-site staff for routine emptying and cleaning, and by technicians for periodic servicing.

[0004] If the reverse vending machine is full, then it must cease operating until it is emptied. Therefore, a reverse vending machine may contain a compactor for reducing the volume of the waste, to lengthen the time between empties.

[0005] A compactor (roll crusher) is an expensive machine that can be damaged if inappropriate objects, such as very hard objects, are inserted into the reverse vending machine and somehow reach the compactor. If blades of the compactor are damaged or broken off, it will become less effective and / or may need replacing. The entire compactor or a substantial part of it generally needs to be replaced.

[0006] A reverse vending machine therefore utilises upstream sensors, as well as geometric constrictions such as a small entrance hole, as a defence to prevent unrecognised objects or materials from entering the reverse vending machine. This also has the effect of preventing inappropriate objects, that could damage the compactor, from reaching the compactor.

[0007] The reliance on highly accurate sensors does however affect the cost of the reverse vending machine. Furthermore, no sensors are 100% accurate, and may still accept an inappropriate object that resembles an acceptable object, but which could damage the compactor.BRIEF DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

[0008] According to various, but not necessarily all, embodiments of the invention there is provided a compactor for a reverse vending machine, the compactor comprising: a drive shaft; a carrier coupled to the drive shaft; and a bladed part user-releasably mounted to the carrier.

[0009] This provides the advantage of reduced maintenance costs for the reverse vending machine as a whole. This is because if the bladed part is damaged due to attempted compaction of an inappropriate object, the bladed part can be replaced without also needing to replace the drive shaft and carrier, or the entire compactor. Such a compactor design is useful for reducing the costs, downtime, and technician time for servicing reverse vending machines. This is especially beneficial when the machines are unsupervised and deployed at several sites, for example in supermarkets or entertainment venues around the country. This is because a technician needs to travel a long distance between sites. Such a compactor design also means that the machine's sensors for detecting and rejecting inappropriate objects are not the only form of protection against damage to the compactor.

[0010] Optionally, the bladed part comprises a blade set comprising a plurality of blades. Optionally, one or more bladed edges of the bladed part define the plurality of blades.

[0011] Optionally, the blade set is formed from a material harder than aluminium, or if it is not harder than aluminium then it is harder than polyethylene terephthalate (PET). Optionally, the material comprises steel or an alloy thereof.

[0012] Optionally, the bladed part comprises a plate. Additionally, or alternatively, the carrier comprises a plate or plates. An advantage of using plates is that the part or parts are low-cost to manufacture, and can be manufactured without specialist tooling. The part may be made using only bending and laser cutting or wire cutting operations. This reduces the overall cost of the compactor and of the reverse vending machine.

[0013] Optionally, the bladed part mostly consists of a plate, or substantially consists of a plate, or consists of a plate. An advantage is that since the bladed part may need to be replaced several times over the lifespan of the compactor, a very low-cost bladed part reduces maintenance costs of the reverse vending machine as a whole.

[0014] Optionally, the plate is formed from a sheet metal, such as sheet steel.

[0015] Optionally, the plate is shaped to define the blade set. Optionally, the blades are portions of the plate. This geometric simplicity advantageously ensures a low manufacturing cost.

[0016] Optionally, the blade set has a tip thickness mostly or substantially equal to a root thickness of the blade set. This advantageously reduces the chance of tip fracture, without impeding crushing ability because sharpness is not required. Optionally, the blade set has a tip thickness substantially equal to a nominal plate thickness of the whole plate. An advantage is that the blades can be formed by the single step of cutting a sheet into a plate with one or more crenelated, toothed, or serrated edges.

[0017] Optionally, the blade set or a first subset of the blade set is formed along a first bladed edge of the bladed part.

[0018] Optionally, the first bladed edge of the bladed part extends longitudinally. The term 'longitudinal' has an understood meaning in the context of compactor blades, since the drive shaft's axis of rotation defines a longitudinal direction.

[0019] Optionally, the first bladed edge of the bladed part is crenelated, toothed, or serrated, to define the blade set or first subset.

[0020] Optionally, the bladed part comprises a base region and a first bladed bent peripheral region along which the first bladed edge extends. Optionally, the first bladed bent peripheral region is bent relative to the base region. Optionally, the base region and first bladed bent peripheral region are regions of the plate.

[0021] Optionally, the base region of the bladed part is generally tangential or circumferential to the drive shaft.

[0022] Optionally, the first bladed bent peripheral region of the bladed part faces a more radial direction than the base region of the bladed part, away from the base region and away from the carrier and drive shaft.

[0023] Optionally, the bladed part is secured to the carrier at the base region.

[0024] Optionally, according to a first design of the bladed part, the blade set further comprises a second subset of blades formed along a second bladed edge of the bladed part. Optionally, the second bladed edge of the bladed part is parallel to and opposite the first bladed edge of the bladed part.

[0025] Optionally, the first design of bladed part is for counter-rotatable crusher units of the compactor.

[0026] Optionally, the first and second bladed edges of the bladed part extend longitudinally.

[0027] Optionally, the second bladed edge of the bladed part is crenelated, toothed, or serrated, to define the second subset of blades.

[0028] Optionally, according to the first design, the bladed part comprises a central region between a pair of bladed bent peripheral regions, the first and second bladed edges each extending along a respective one of the pair of bladed bent peripheral regions.

[0029] Optionally, the central region is the base region described above. Optionally, the pair of bladed bent peripheral regions comprises the first bladed bent peripheral region described above, comprising the first bladed edge, and a second bladed bent peripheral region opposite the first bladed bent peripheral region, the second bladed bent peripheral region comprising the second bladed edge.

[0030] Optionally, the compactor alternatively or additionally comprises a bladed part according to a different, second design. Optionally, the second design is bladed along fewer edges than the first design, for example only one edge.

[0031] Optionally, the bladed part according to the second design has fewer bladed bent peripheral regions than the first design, for example only one such region.

[0032] Optionally, the bladed part according to the second design is user-releasably mounted to a different carrier mounted to a different drive shaft than the bladed part according to the first design. Optionally, the second design of bladed part is for a pre-feeder roller unit of the compactor, comprising the different carrier and different drive shaft. Optionally, the pre-feeder roller unit is configured to guide objects to the crusher units and force the objects into the crusher units. This advantageously prevents objects from `floating' on the crusher units. Many drink containers have a rounded shape that is susceptible to floating' on the crusher units. As well as forcing objects towards the crusher units, the pre-feeder roller unit may initiate crushing of objects, which changes the shape of the object to further assist the crusher units in grabbing and pulling in the object.

[0033] Optionally, the bladed part according to the second design comprises a cantilevered portion cantilevered beyond an edge of a face of a carrier to which the bladed part is mounted, cantilevered in a direction substantially parallel to a plane of said face. An advantage is that objects are guided and forced into the separate crusher units.

[0034] Optionally, the cantilevered portion comprises a portion of the base region of the bladed part according to the second design. Optionally, the cantilevered portion further comprises the first bladed bent peripheral region of the bladed part according to the second design.

[0035] Optionally, both the first and second designs of the bladed part are advantageously compatible with the same carrier geometry.

[0036] Optionally, the bladed part comprises a fixing point configured to receive a user-releasable fixing to user-releasably mount the bladed part to the carrier.

[0037] Optionally, the carrier comprises a corresponding carrier fixing point with which the fixing point of the bladed part is alignable.

[0038] Optionally, the carrier fixing point is threaded. Optionally, the carrier fixing point comprises a threaded hole. An advantage is ease of manufacture and bladed part replacement, because a separate captive nut does not need to be installed inside the carrier, or the carrier does not need to be disassembled to position a nut inside the carrier.

[0039] Optionally, the fixing comprises a mechanical fastener.

[0040] Optionally, the mechanical fastener comprises a bolt.

[0041] Optionally, the mechanical fastener comprises a shank, and a tool-receiving portion, such as a fastener head, protruding from an exterior side of the bladed part, enabling tightening of the bladed part to the carrier, and enabling release of the bladed part from the carrier for replacement of the bladed part.

[0042] Optionally, the tool-receiving portion of the mechanical fastener is recessed relative to blade roots of the bladed part. An advantage is that the mechanical fastener is protected from damage during compaction.

[0043] Optionally, if the bladed part is a bent plate as described earlier, the tool-receiving portion of the mechanical fastener is located at the base region of the plate, and recessed relative to the or each bladed edge of the plate in the or each bladed bent peripheral region of the plate.

[0044] Optionally, the bladed part comprises a pair of the fixing points, enabling a pair of the fixings to user-releasably mount the bladed part to the carrier. Optionally, the carrier bladed part comprises a pair of the carrier fixing points, with which the pair of fixing points of the bladed part are alignable.

[0045] Optionally, the bladed part is user-releasably mounted to the carrier by no more than two or no more than four of the fixings. An advantage is minimising the number of steps required to effect release.

[0046] Optionally, the compactor comprises a plurality of the bladed parts mounted to the carrier. Optionally, each bladed part is individually user-releasably mounted to the carrier. An advantage is that if one bladed part is damaged, it can be replaced without replacing or even temporarily removing the other bladed parts mounted to the same carrier.

[0047] Optionally, the compactor comprises three or more of the bladed parts mounted to the carrier. Optionally, the compactor comprises different numbers of the bladed parts mounted to each of different carriers of the compactor.

[0048] Optionally, the carrier comprises a drum or is a drum to which the plurality of the bladed parts are mounted, facing in different directions than each other.

[0049] Optionally, the carrier is formed from one or more carrier plates. Optionally, the drum is formed from carrier plates. An advantage is that similar manufacturing techniques and machinery can be used to manufacture the carrier, as well as the bladed parts.

[0050] Optionally, the drum defines a polygonal shape, the plurality of bladed parts being mounted to different faces of the polygonal shape.

[0051] Advantages of a polygonal shape are a generally flat bearing surface for the fixings mounting the toothed part, as well as low-cost manufacture due to the ability to use laser cutting or wire cutting, and bending.

[0052] Optionally, the drum comprises a pair of end plates, one or each of which is coupled to the drive shaft.

[0053] Optionally, the drum comprises a plurality of longitudinal carrier plates, providing substrates to which the bladed parts are mounted. An advantage of using several longitudinal carrier plates to define a closed polygonal drum shape is ease of manufacture.

[0054] Optionally, each longitudinal carrier plate is connected at each end region to a respective one the end plates.

[0055] Optionally, at least one of the longitudinal carrier plates comprises one or more bends to define more than one face of the polygonal shape.

[0056] Optionally, the drum comprises a pair of the longitudinal carrier plates, each longitudinal carrier plate comprising a plurality of parallel bends to define, at least in part, a plurality of faces of the polygonal shape. Optionally, each longitudinal carrier plate is bent to define half of the faces of the polygonal shape.

[0057] Optionally, the drive shaft extends through the carrier between a pair of opposing bearings. An advantage is that torque is not transmitted through the carrier, which could result in twisting or deformation of the carrier.

[0058] Optionally, the compactor comprises a plurality of roller units including a pair of counter-rotatable crusher units. Optionally, each counter-rotatable crusher unit comprises one of the drive shaft, one of the carrier, and one or more of the bladed parts, wherein the compactor is configured to drive the drive shafts of the counter-rotatable crusher units in opposite directions, and wherein the bladed parts of the counter-rotatable crusher units have a crushing space therebetween. Optionally, the counter-rotatable crusher units comprise bladed parts according to the first design.

[0059] Optionally, the plurality of roller units of the compactor further comprises a pre-feeder roller unit upstream of the pair of counter-rotatable crusher units, the pre-feeder roller unit comprising one of the drive shaft, one of the carrier, and one or more of the bladed parts. Optionally, the pre-feeder roller unit is above the pair of counter-rotatable crusher units. Optionally, the pre-feeder roller unit comprises bladed parts according to the second design.

[0060] Optionally, the compactor comprises a compactor actuator, such as an electric motor, to drive the or each drive shaft of the compactor.

[0061] Optionally, a first one of the roller units is coupled to the compactor actuator, and a second one the roller units is coupled to the first roller unit via a transmission mechanism.

[0062] Optionally, the transmission mechanism comprises a gear transmission mechanism, and / or a chain or belt transmission mechanism.

[0063] Optionally, the compactor is a drinks container compactor.

[0064] According to various, but not necessarily all, embodiments of the invention there is provided a reverse vending machine comprising the compactor. According to various, but not necessarily all, embodiments of the invention there is provided a reverse vending machine comprising an automated sorting system to sort drinks containers into a selected one of first and second compactors.

[0065] Optionally, the compactor actuator is configured to drive the drive shaft of each of the first and second compactors. Optionally, the compactor actuator is a common design for the first and second compactors.

[0066] Optionally, the reverse vending machine comprises a sensor system and a control system collectively configured to control the automated sorting system to sort aluminium drink cans into the first compactor, and plastic drink bottles into the second compactor.

[0067] Optionally, the first and second compactors are of different sizes, e.g., widths. Optionally, the automated sorting system is configured to sort aluminium drink cans into the smaller of the compactors, and to sort plastic drink bottles into the larger of the compactors. An advantage is that the reverse vending machine can accept large plastic drink bottles such as two litre or three litre drinks bottles.

[0068] Optionally, the counter-rotatable crusher units of the first and second compactors have a different number of bladed parts mounted to each respective carrier, and / or have a different blade geometry, and / or have different plate thicknesses of the bladed parts. An advantage is that the roller units are optimised for crushing the different types of materials and different container dimensions. For example, a shape memory material such as plastic may require more aggressive crushing, whereas a ductile material such as aluminium may require less aggressive crushing to prevent shredding.

[0069] Optionally, the first and second compactors have different phase offsets between their counter-rotatable crusher units. For one of the compactors, the bladed parts of its crusher units may be at a first phase relative to each other, so that the bladed parts interdigitate with each other. For the other compactor, the bladed parts of its crusher units may be at a different phase relative to each other, with less or no interdigitation. An advantage is that the roller units are optimised for crushing different types of materials or objects.

[0070] Optionally, the bladed parts of the counter-rotatable crusher units of the first and second compactors have bladed parts of different plate thicknesses mounted to their respective carriers. An advantage is that the roller units are optimised for crushing different types of materials or objects.

[0071] Optionally, the reverse vending machine comprises a storage space beneath the first and second compactors to receive storage carriers for storing compacted containers from the first and second compactors, respectively. Optionally, the storage carriers comprise bins and / or bin bags.

[0072] Optionally, the reverse vending machine comprises a lockable closure configured to be unlocked and opened to enable access to the storage space.

[0073] Optionally, the reverse vending machine comprises a frame to locate and / or support tops of the storage carriers in alignment with the first and second compactors.

[0074] Optionally, the reverse vending machine comprises a roll-off floor for the storage space, less than 10cm above ground level, enabling storage bins to be rolled out of or slid out of the storage space.

[0075] According to another embodiment, the reverse vending machine has only one compactor and therefore only one storage carrier.

[0076] According to various, but not necessarily all, embodiments of the invention there is provided a bladed part for a compactor, the bladed part comprising one or more fixing points allowing the bladed part to be user-releasably mounted to a carrier of the compactor.

[0077] According to various, but not necessarily all, embodiments of the invention there is provided a carrier for a compactor, the carrier further being mounted or mountable to a shaft, and the carrier comprising one or more carrier fixing points allowing a bladed part for the compactor to be user-releasably mounted to the carrier.

[0078] According to various, but not necessarily all, embodiments of the invention there is provided a reverse vending machine comprising the compactor.

[0079] According to various, but not necessarily all, embodiments of the invention the compactor is a drinks container compactor. The drinks container compactor may be an aluminium drink can compactor or a plastic drink bottle compactor.

[0080] According to various, but not necessarily all, embodiments of the invention there is provided a compactor comprising: a drive shaft; a carrier coupled to the drive shaft; and a bladed part user-releasably mounted to the carrier.

[0081] According to various, but not necessarily all, embodiments of the invention there is provided a reverse vending machine comprising an automated sorting system, a first compactor, and a second compactor, wherein the automated sorting system is to sort objects into the first compactor and the second compactor, wherein each compactor comprises a pair of counter-rotatable crusher units each comprising one or more bladed parts, and wherein the pair of counter-rotatable crusher units of the first compactor have a different blade arrangement than the pair of counter-rotatable crusher units of the second compactor.

[0082] Optionally, the blade arrangements differ to cause the first and second compactors to have a different degree of blade interdigitation. Optionally, the blade arrangements differ in one or more of the following ways to cause the different degree of blade interdigitation: a number of the bladed parts mounted to each counter-rotatable crusher unit; blade thicknesses of bladed parts; or phase offsets.

[0083] Optionally, the blade arrangements differ by having different blade geometries.BRIEF DESCRIPTION OF THE DRAWINGS

[0084] For a better understanding of various examples of embodiments of the present invention reference will now be made by way of example only to the accompanying drawings in which: FIG. 1 schematically illustrates a front elevation of an example reverse vending machine; FIG. 2 schematically illustrates a rear elevation of an example reverse vending machine with the rear panel removed; FIG. 3 schematically illustrates a perspective cutaway view of an example compactor; FIGS. 4A, 4B schematically illustrate first and second designs of a bladed part for a compactor, respectively; FIG. 5 schematically illustrates an example exploded view of an example carrier and shaft of a compactor; and FIGS. 6A-6B schematically illustrate perspective cutaway views of first and second example compactors. DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

[0085] The Figures illustrate a reverse vending machine (RVM) 100 for recycling, the RVM 100 comprising compactors 200. Some embodiments of the invention are applicable to compactors for other uses, not restricted to RVMs.

[0086] FIG. 1 illustrates a front elevation of the RVM 100 seen by the user. The user inserts objects in exchange for tokens, currency, or other benefits.

[0087] The RVM 100 is optionally a compact design when viewed in top-down plan view, for example less of than 1.5 metres squared. Such a size is suitable for thoroughfares or limited size spaces in retail or entertainment venues, among other things. The size is similar to that of standard vending machines. Many of the internal components described herein have been specifically adapted for the compact dimensions of the RVM 100. However, the features disclosed herein are also applicable to larger RVMs.

[0088] The RVM 100 crushes / compacts inserted objects to maximise the number of objects that can be stored therein.

[0089] The RVM 100 in FIG. 1 comprises a front door 104 (lockable closure) or doors 104 locked in a closed position by a door lock 106. The RVM 100 further comprises a machine entrance 112, which is shown as a hole in a front door 104 or panel of the RVM 100, at a height of over 120cm about the ground.

[0090] FIG. 2 schematically illustrates a rear elevation of the RVM 100, with its rear panel removed to expose its chassis 102 and some internal components.

[0091] A control system 116 and sensor system 118 are schematically shown. The control system comprises one or more processors. In a non-limiting use case, the control system 116 and the sensor system 118 of the RVM 100 are configured to accept plastic drink bottles of varying sizes up to and including two litre bottles or even three litre bottles, and are also configured to accept aluminium drink cans. The plastic drink bottles and aluminium drink cans are stored separately within the RVM 100.

[0092] In a use case, the sensor system 118 comprises a weight sensor, an optical sensor, and / or a magnetic sensor.

[0093] When a user inserts a drinks container through the machine entrance 112 of FIG. 1 onto a conveyor 113, the drinks container is scanned by the sensor system 118 and transported rearwardly / downstream away from the machine entrance 112 by the conveyor 113 (shown in the detail view of FIG. 1) if it is accepted.

[0094] Acceptance means that the control system 116 receives signals from the sensor system 118 indicative of characteristics of an object, processes the sensed information to determine whether the characteristics satisfy numerical and / or geometric criteria, and if so, outputs a control signal to operate a belt actuator to control the conveyor 113 to transport the object (putative drinks container) downstream for compacting and storing.

[0095] If the object is rejected, it is returned to the user. Rejection means that the control system 116 determines that the sensed information does not satisfy at least one of the numerical and / or geometric criteria, and therefore outputs a second control signal to operate the belt actuator to control the conveyor 113 to transport the object upstream, back towards the machine entrance 112. The user then takes the object back.

[0096] For example, an object may be rejected if a weight sensor of the sensor system 118 indicates that it is too heavy, which could be because the drinks container has excessive liquid inside, or that the drinks container is a glass bottle, or that an incorrect type of object has been inserted.

[0097] FIG. 2 schematically illustrates an automated sorting system 114 to receive the drinks container from the conveyor 113 of FIG. 1 (hidden from view in FIG. 2), and sort aluminium drink cans and plastic drink bottles into separate recycling streams. Full details of the automated sorting system 114 are outside the scope of this disclosure.

[0098] The aluminium drink cans are dropped by the automated sorting system 114 into a first compactor 200A, and the plastic drink bottles are dropped by the automated sorting system 114 into a second compactor 200B.

[0099] The first and second compactors 200A, 200B are shown alongside each other and beneath the automated sorting system 114. The second compactor 200B has a larger compacting volume than the first compactor 200A because the maximum size of a plastic drink bottle is typically larger than the maximum size of an aluminium drink can. Specifically, the illustrated second compactor 200B is wider than the first compactor 200A.

[0100] For example, the width of the first compactor 200A is 15cm or another value from the range 10cm to 20cm, whereas the width of the second compactor 200B is greater than that of the first compactor 200A, for example 5cm wider or at least 3cm wider.

[0101] Despite the extra width, the second compactor 200B may still have a width of only 20cm or less than 22cm or less than 25cm, if the automated sorting system 114 and / or funnels orientate the drinks container appropriately. Therefore, large drink containers can be received without needing a large compactor 200B.

[0102] A compactor actuator 201 is shown between the first and second compactors 200A, 200B, in the form of an electric motor. The same electric motor is configured to drive both compactors. They may be driven simultaneously. Separate electric motors are another possibility.

[0103] FIG. 3 is a perspective view of a compactor 200, specifically 200A, with one side wall and features mounted thereto removed to expose internal roller units 202, 204, 206.

[0104] FIG. 3 shows that the compactor 200 has multiple roller units 202, 204, 206 each comprising a drive shaft 208. Turning back to FIG. 2, a gear transmission mechanism 211 is shown which couples the drive shafts 208 to each other, allowing a single output shaft of the compactor actuator 201 to drive all the drive shafts 208. The gear transmission mechanism 211 causes a pair of the drive shafts 208 to rotate in opposite directions, resulting in a pair of counter-rotatable crusher units 204, 206. In other examples, chains or belts could be used rather than gears.

[0105] FIG. 2 also shows that a storage space 108 is located beneath the first and second compactors 200A, 200B. Storage carriers (not shown) such as bin bags or wheelie bins may be located beneath the compactors 200A, 200B, to catch compacted drinks containers. Compacted plastic drink bottles fall into a different storage carrier than compacted aluminium drink cans.

[0106] The RVM 100 can comprise a frame 110 such as bin top tubes, to locate and / or support the tops of bin bags or wheelie bins in alignment with the first and second compactors 200A, 200B.

[0107] If wheelie bins or slidable bins are provided, the low height of the floor 109 of the storage space 108 is useful, because it is generally flat and less than 10cm above the bottom of the RVM 100.

[0108] In another example, the storage carriers are in a location other than below the compactors 200A, 200B, and a suitable conveying means is provided to transport the compacted drinks containers to the storage carriers.

[0109] According to another embodiment, the RVM 100 has only one compactor and therefore only one storage carrier.

[0110] Turning fully to FIG. 3, three roller units 202, 204, 206 are shown, for the first compactor 200A. The second compactor 200B may be identical to FIG. 3 notwithstanding the greater width and other minor variations.

[0111] The roller units 202, 204, 206 firstly comprise an optional, upper pre-feeder roller unit 202 to initially receive the drinks container falling from the automated sorting system 114, and a pair of lower counter-rotatable crusher units 204, 206 below the pre-feeder roller unit 202, to compact the drinks container. The pre-feeder roller unit 202 forces the drinks container into the crusher units 204, 206.

[0112] Embodiments of the invention further apply to a compactor 200 with only the counter-rotatable crusher units 204, 206, or even only one crusher unit 204. However, the benefit of the three roller units 202, 204, 206 shown in FIG. 3 is that drinks containers are compacted quickly, allowing a user to insert multiple drinks containers in rapid succession.

[0113] Each roller unit 202, 204, 206 comprises a drive shaft 208, a carrier 210 rotatably coupled to the drive shaft 208, and a plurality of bladed parts 212 mounted to the carrier 210. Embodiments of the invention also apply to implementations with only one bladed part 212 mounted to the carrier 210.

[0114] The compactor 200 comprises a pair of counter-rotatable crusher units 204, 206, each comprising a drive shaft 208, a carrier 210, and one or more bladed parts 212A according to a first design

[0115] The transmission mechanism 211 (FIG. 2) is configured to rotate the drive shafts 208 of the counter-rotatable crusher units 204, 206 in opposite directions. The bladed parts 212A of the counter-rotatable crusher units 204, 206 are configured to define a narrow crushing space 207 therebetween of only a few cm. The crushing space 207 may be so narrow that the bladed parts 212A of the counter-rotatable crusher units 204, 206 interdigitate.

[0116] The roller units 202, 204, 206 for a given compactor are mostly standardised, with only the bladed parts 212B of the pre-feeder roller unit 202 being different than the bladed parts 212A of the counter-rotatable crusher units 204, 206. A common design of shaft is provided for each roller unit 202, 204, 206, and a common design of carrier 210 FIG. 5 is provided for each roller unit 202, 204, 206. The counter-rotatable crusher units 204, 206 each comprise bladed parts 212A according to a first design of FIG. 4A. The pre-feeder roller unit 202 comprises bladed parts 212B according to a second design of FIG. 4B.

[0117] Turning now to FIG. 4A, a bladed part 212A according to the first design is described in detail. The bladed part 212A is used for the counter-rotatable crusher units 204, 206. The bladed part 212A can be rapidly and cost-effectively formed by sheet bending and laser / wire cutting operations.

[0118] The bladed part 212A is a plate 220 formed from a sheet steel or another sheet metal, having a constant thickness of 3mm or 6mm or any other constant thickness value from the range 2-8mm. The plate 220 comprises two blade subsets 236, 238 of blades 240 defining a full blade set 234, each defined by a respective bladed edge of the plate 220.

[0119] Specifically, the plate 220 comprises opposite first and second bladed edges 222, 224 each extending longitudinally, i.e., parallel to the drive shaft's rotation axis, and further comprises opposite first and second straight side edges 226, 228 extending transversely and perpendicularly to the first and second bladed edges 222, 224, and connecting the first and second bladed edges 222, 224.

[0120] The first and second bladed edges 222, 224 are crenelated (toothed) edges formed by a manufacturing technique such as laser / wire cutting. Therefore, the blades 240 defined by the bladed edges are integral portions of the plate 220, and have the same geometry as each other. No additional manufacturing steps are involved to sharpen the blades 240, because drinks containers are generally easy to crush.

[0121] The plate 220 is bent along two parallel longitudinal bends 241 to form a generally flat base region 230 (central region) between opposite first and second bladed bent peripheral regions 231, 232 (bent wings). The first bladed bent peripheral region 231 comprises the first bladed edge 222, and the second bladed bent peripheral region 232 comprises the second bladed edge 224.

[0122] The first and second bladed bent peripheral regions 231, 232 are each pitched up from the base region 230 by an angle of 60 degrees, or another angle from the range 30 to 90 degrees. Therefore, the blades 240 are pitched up by 60 degrees relative to the base region 230, radially away from the carrier 210 and drive shaft 208. This has the effect of crushing the drinks container.

[0123] The plate 220 optionally comprises a line of symmetry extending longitudinally along the base region 230 halfway between the first and second bladed bent peripheral regions 231, 232, about which the first and second bladed bent peripheral regions 231, 232 are symmetrical. The first and second bladed edges 222, 224 may or may not be symmetrical depending on whether the individual blades 240 line up.

[0124] Optionally, the length of a bladed edge 222, 224 of each bladed part 212, measured in the longitudinal (shaft) direction between the centres of its end blades 240, is from the range 75% to 95% of the corresponding width of the compactor 200. As a result, with the second compactor 200B being wider than the first compactor 200A, the bladed parts 212 for the second compactor 200B are longer than the bladed parts 212 for the first compactor 200A.

[0125] As shown in FIGS. 6A-6B, bladed parts 212A1 for the first compactor 200A may differ from the bladed parts 212A2 for the second compactor 200B in minor ways, while still being in accordance with the first design. For example, the bladed parts 212A1 for the first compactor 200A for crushing aluminium drink cans may be thinner, e.g., 3mm thick plates 220, than the bladed parts 212A2 for the second compactor 200B for crushing plastic drink bottles, e.g., 6mm thick plates 220.

[0126] This lower thickness can reduce the degree of blade interdigitation, which is beneficial when the goal is to compact drink containers, rather than shred them. Aluminium is ductile and more susceptible to shredding than plastic.

[0127] For similar reasons, the bladed parts 212A1 for the crusher units 204, 206 of the first compactor 200A for crushing aluminium drink cans may be more out-of-phase with each other than those of the second compactor 200B, to reduce or prevent blade interdigitation.

[0128] This phase offset may be up to 50%, which is 30 degrees for the depicted six-sided crusher units 204, 206 which present blades towards each other for every 60-degree rotation. The minimum phase offset for the first compactor 200A may be such that the blades do not interdigitate (overlap). This depends on the thickness of the blades, but could be for example at least 10% phase offset, or at least 15% phase offset. This avoidance of interdigitation ensures that aluminium drink cans are crushed rather than shredded. The bladed edge 222 or 224 on one crusher unit 204 may be aligned with a face 246 of the carrier 210 or with a base region 230 of the bladed part 212A1 on the other crusher unit 206.

[0129] As shown in FIG. 6B, the bladed parts 212A2 for the crusher units 204, 206 of the second compactor 200B for crushing plastic drink bottles may be more in-phase with each other than those of the first compactor 200A, and might at least partially interdigitate (overlap). This is the result of a smaller phase offset than the first compactor 200A, and / or the greater thickness of the bladed parts 212A2 than the bladed parts 212A1 of the first compactor 200A. The maximum phase offset depends on the thickness of the blades of the bladed parts 212A2, but may be selected from the range 0-15%. This aggressive crushing geometry ensures that plastic drinks bottles stay in their compacted shapes, overcoming the shape memory tendencies of plastic.

[0130] The blades 240 may be formed as cuts through the thickness of the plate 220. Each individual blade 240 has a length of approximately 4-5mm, or from the range 2.5-7.5mm. Each individual blade 240 has a width of approximately 10mm, or from the range 5-15mm.

[0131] Each individual blade 240 is formed as a crenelated cut with a radius along the cut to define tip corners / shoulders of the blade 240. Each blade 240 has a constant thickness from its root to its tip, which is the same as the thickness of the base region 230 and first and second bladed bent peripheral regions 231, 232. The blades 240 are therefore merely cut into the plate 220 by laser / wire cutting operations or similar, before (or after) the plate 220 is bent to form the first and second bladed bent peripheral regions 231, 232.

[0132] Advantageously, the bladed part 212A is individually user-releasably mounted to the carrier 210, enabling its replacement without replacing the carrier 210, or removing or loosening any of the other bladed parts 212A mounted to the carrier 210, and without even having to remove the carrier 210 from the drive shaft 208.

[0133] To achieve this, FIG. 4A shows the bladed part 212A comprising two fixing points 216, in this example a pair of longitudinally spaced holes each configured to receive a mechanical fastener fixing 214 or more specifically a bolt shank 214B.

[0134] The illustrated mechanical fastener 214 is a bolt comprising a threaded shank 214B and a head 214A with a tool-receiving portion such as a spanner-receiving head, a screwdriver-receiving recess, or a hex key-receiving socket.

[0135] The fixing points 216 are of the same dimensions to receive the same mechanical fastener size. The mechanical fasteners 214 each have the same type of tool-receiving portion so that one tool can be used.

[0136] FIG. 5 shows the carrier 210 comprising underlying carrier fixing points 218 in the form of a pair of longitudinally spaced threaded holes. The holes in the carrier 210 are threaded so that the operator does not require access to the interior of the carrier 210 to secure a nut.

[0137] To protect the mechanical fastener 214 from damage, the top of the head 214A of the mechanical fastener 214 is recessed below the blade tips of the blades 240, or is further recessed below the blade roots of the blades 240.

[0138] Turning now to FIG. 4B, a bladed part 212B according to the second design is described in detail. The bladed part 212B is used for the pre-feeder roller unit 202.

[0139] The bladed part 212B of FIG. 4B is similar to that of FIG. 4A, because it is a plate 220 with a base region 230 and a first bladed bent peripheral region 231, and has the same type of fixing points 216 with the same dimensions and same spacing therebetween.

[0140] However, FIG. 4B shows that the bladed part 212B differs from that of FIG. 4A in one or more ways.

[0141] Firstly, the bladed part 212B of FIG. 4B comprises only one bend 241 meaning there is only one bladed bent peripheral region 231.

[0142] Additionally, or alternatively, the first bladed edge 222 of the bladed part 212B has a different blade geometry. In this instance, the blade geometry of the first bladed edge 222 of FIG. 4B is less aggressive than the blade geometry of the first and second bladed edges 222, 224 of the bladed part 212A of FIG. 4A. The blade geometry in FIG. 4B is better described as serrated whereas the blade geometry of FIG. 4A is better described as crenelated or toothed.

[0143] Additionally, or alternatively, a portion of the first bladed bent peripheral region 231 of the bladed part 212B of FIG. 4B is cantilevered beyond the edge of a flat face 246 (FIG. 5) of the carrier 210 to which the bladed part 212B is mounted, in-plane with the face 246.

[0144] To achieve this, the base region 230 of FIG. 4B is wider than that of FIG. 4A so that a portion of the base region 230 is cantilevered from the carrier 210.

[0145] Additionally, or alternatively, the plate 220 of FIG. 4B has an asymmetric geometry with its fixing points 216 being distal from the first bladed edge 222 and proximal to the opposite edge 225 of the plate 220 than the first bladed edge 222. In FIG. 4B, the fixing points 216 are distal from the bend 241 and proximal to the opposite edge 225. In FIG. 4B, the distance from the centre of a fixing point 216 to the bend 241 between the base region 230 and the first bladed bent peripheral region 231 may be more than twice, or more than three times as long as the corresponding distance in FIG. 4A.

[0146] Additionally, or alternatively, the bladed part 212B of FIG. 4B comprises bent side regions 227, 229 each comprising one of the first and second straight side edges 226, 228 of the plate 220. This provides additional stiffness, for example if the bladed part 212B is cantilevered as described above. Optionally, the bent side regions are bent upwardly like the first bladed bent peripheral region 231. Optionally, the plate 220 of FIG. 4B is bent up along at least three out of its four sides due to the regions 227, 229, 231.

[0147] Turning now to FIG. 5, the carrier 210 is described in detail with reference to the exploded view. The carrier 210 is the same for all the different types of roller units 202, 204, 206.

[0148] The carrier 210 can be referred to as a drum 242. The illustrated carrier 210 is a hexagonal drum 242 with six generally flat faces 246, or alternatively another form of polygonal shape with three or more generally flat faces, or four or more faces, or five or more faces. As shown in FIGS. 3-5 collectively, the generally flat base region 230 of a bladed part 212 abuts flatly against the generally flat face 246 of the carrier 210.

[0149] Each face 246 of the illustrated drum 242 comprises a plurality of carrier fixing points 218 in the form of threaded holes, which align with the fixing points 216 of the bladed part 212 enabling the mechanical fasteners 214 to extend through the fixing points 216 of the bladed part 212 into the carrier fixing points 218, and engage with the threads of the carrier fixing points 218 to clamp the bladed part 212 to the carrier 210.

[0150] The use of threaded holes for the carrier fixing points 218 obviates the need for nuts. An internal nut would either need to be a captive nut which increases cost and complexity, or would require the bladed parts 212 to be mounted or dismounted while the carrier 210 is in a disassembled state.

[0151] Although each face 246 of the carrier 210 comprises carrier fixing points 218, FIG. 3 shows that the counter-rotatable crusher units 204, 206 of the first compactor 200A each have fewer bladed parts 212A mounted to the carrier 210 than the number of faces 246 of the carrier 210 that have carrier fixing points 218. Specifically, three bladed parts 212A are mounted to the carrier 210, because one bladed part 212A is mounted to every other face 246 of the carrier 210.

[0152] However, the second compactor 200B may have six bladed parts 212A mounted to the carrier 210, mounted to every face 246 of the carrier 210. The specifics may vary, but this demonstrates that the crushing characteristics of each compactor 200A, 200B may be controlled by varying the number and / or type of bladed parts 212 mounted to each standardised carrier 210.

[0153] FIG. 5 shows that the carrier 210 itself, like the bladed parts 212, can be formed from plates that are cut and bent to a required shape, for low-cost and high-volume manufacturing. The same manufacturer that makes the bladed parts 212 can also make the carriers 210.

[0154] FIG. 5 shows the carrier 210 being formed from carrier plates 244, 252. The carrier 210 is formed from two end plates 252 spaced along the drive shaft 208, and a plurality / pair of longitudinal carrier plates 244 mounted to the end plates 252 and extending therebetween.

[0155] A pair of longitudinal carrier plates 244 is shown, each longitudinal carrier plate 244 comprising a plurality of parallel longitudinal bends 250 so that the longitudinal carrier plate 244 forms a drum half, in this case a half-hexagon. The number of longitudinal carrier plates 244 and the number of such bends 250 depends of course on the required polygon shape and the required number of longitudinal carrier plates 244.

[0156] The longitudinal carrier plates 244 may be plug welded or otherwise permanently secured to the end plates 252, for strength and rigidity. The end plates 252 may likewise be welded or otherwise permanently secured to the drive shaft 208. These parts do not experience much wear and tear, and may last the entire lifetime of the compactor 200, so permanent connections are used. In other embodiments, one or more of the elements shown in FIG. 5 are releasably mounted rather than being welded.

[0157] In FIG. 5, the carrier 210 has a hollow interior through which the drive shaft 208 extends, wherein both end plates 252 are mounted to the same drive shaft 208. The drive shaft 208 is held by a pair of opposing bearings (not shown), and extends through the inside of the carrier 210 so that torque is not transmitted through the carrier 210, which could result in twisting or deformation of the carrier 210.

[0158] Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed, for example by releasably mounting bladed plates directly to the end plates 252 (the end plates 252 would function as carriers 210).

[0159] Features described in the preceding description may be used in combinations other than the combinations explicitly described.

[0160] Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

[0161] Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

[0162] Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and / or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A compactor for a reverse vending machine, the compactor comprising: a drive shaft; a carrier coupled to the drive shaft; and a bladed part user-releasably mounted to the carrier.

2. The compactor of claim 1, wherein the bladed part comprises a blade set comprising a plurality of blades.

3. The compactor of claim 2, wherein the bladed part comprises a plate, and wherein the plate is shaped to define the blade set.

4. The compactor of claim 2 or 3, wherein the blade set has a tip thickness equal to a root thickness of the blade set.

5. The compactor of claim 2, 3, or 4, wherein the blade set or a first subset of the blade set is formed along a first bladed edge of the bladed part, and wherein the first bladed edge of the bladed part extends longitudinally, and wherein the bladed part comprises a base region and a first bladed bent peripheral region along which the first bladed edge extends.

6. The compactor of claim 5, wherein according to a first design of the bladed part, the blade set further comprises a second subset of blades formed along a second bladed edge of the bladed part, wherein the compactor further comprises a bladed part according to a different, second design, and wherein the bladed part according to the second design: is bladed along fewer edges than the first design; and / or has fewer bent peripheral regions than the first design; and / or is user-releasably mounted to a different carrier mounted to a different drive shaft than the bladed part according to the first design; and / or comprises a cantilevered portion cantilevered beyond an edge of a face of a carrier to which the bladed part according to the second design is mounted, cantilevered in a direction substantially parallel to a plane of said face.

7. The compactor of claim 5 or 6, wherein the bladed part is secured to the carrier at the base region.

8. The compactor of any preceding claim, wherein the bladed part comprises a fixing point configured to receive a releasable fixing to mount the bladed part to the carrier, and wherein the carrier comprises a corresponding carrier fixing point with which the fixing point of the bladed part is alignable.

9. The compactor of claim 8, wherein the carrier fixing point comprises a threaded hole, and wherein the fixing comprises a mechanical fastener.

10. The compactor of any preceding claim, wherein the compactor comprises a plurality of the bladed parts individually releasably mounted to the carrier.

11. The compactor of claim 10, wherein the carrier comprises a drum to which the plurality of the bladed parts are mounted, facing in different directions than each other.

12. The compactor of claim 11, wherein the drum defines a polygonal shape, the plurality of bladed parts being mounted to different faces of the polygonal shape, and / or wherein the drum comprises a pair of end plates, one or each of which is coupled to the drive shaft, and wherein the drum comprises a plurality of longitudinal carrier plates, providing substrates to which the bladed parts are mounted.

13. A reverse vending machine comprising the compactor according to any one or more of the preceding claims.

14. The reverse vending machine of claim 13, wherein the compactor is a first compactor, and wherein the reverse vending machine further comprises a second compactor according to any one or more of the preceding claims.

15. The reverse vending machine of claim 14, wherein the first and second compactors each comprise a pair of counter-rotatable crusher units, wherein the counter-rotatable crusher units of the first and second compactors differ in one or more of the following ways: the number of the bladed parts; the blade geometry of the bladed parts; the plate thicknesses of the bladed parts; or phase offsets of the bladed parts of the pair of counter-rotatable crusher units.

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