WO2014106687A1

WO2014106687A1 - Roller conveyor and reverse vending machine

Info

Publication number: WO2014106687A1
Application number: PCT/FI2014/050001
Authority: WO
Inventors: Tuomas RITOLA
Original assignee: Aalto University Foundation
Priority date: 2013-01-03
Filing date: 2014-01-02
Publication date: 2014-07-10
Also published as: FI20135008L

Abstract

(57) Abstract The invention relates to a roller conveyor for advancement of discrete articles along a predetermined path, and a reverse vending machine making use of such a roller conveyor. The roller conveyor includes a support frame structure and a plurality of roller conveying modules (12) supported by the support frame structure (11) and placed successively along said path. Each of said modules comprises a set of mutually spaced rollers (13) extending transversely to the direction of said path. At least one endless element is supported by the frame structure and is driven along a track beneath the rollers (13) and frictionally engaging the rollers of the modules. At least one quick-release means is used to fasten and release each module to and from the support frame structure.

Description

Roller conveyor and Reverse Vending Machine

The present invention relates io roller conveyors, and more specifically to roller conveyors for advancement of discrete commodities along a predetermined path, comprising a plurality of successive conveying modules. The invention also relates to a Reverse Vending Machine.

Conveyors for transporting discrete goods are widely used in industry and commerce. Both belt conveyors and roller conveyors are used, depending on the goods, the weight of the goods and the environment the conveyor is installed, industry grade roller conveyors are usually designed for transfer of heavy equipment or semi-finished products like machinery etc. from one place to another. Belt conveyors, being lighter in construction and design, are used for a variety of purposes also in security industry, retail shops etc. One specific requirement that many conveyors have is to withstand contamination and dirt. Therefore durability, easy access for cleaning and maintenance, as well as a simple construction to facilitate quick replacement of failed parts, are essential design criteria, in most instances only trained personnel may access the conveyor constructions, which makes operation stops an issue, if they happen frequently. Especially in the retail industry, and specifically in the case of Reverse Vending Machines (RVM), this is presently a problem, in certain countries, the gross majority of beverage retail packages, as a major way of arranging recycling of glass, plastic materials and aluminum, are returned to the shops in return for a deposit fee charged upon purchase of the product, in popular markets and shopping malls the RVM's are in constant use, receiving unsorted packages that frequently still contain liquids, are broken, or are covered with dirt, sand, etc. it is a known fact that RVMs in grocery stores are often malfunctioning or out of order, The main reasons for maintenance are usability problems, failed mechanics in conveyor systems or compactors, and the general dirtiness of the mside of the RVM. Typically, prior art conveyors provide potential hard- to-reach places for liquid residue to accumulate over time. In principle belt conveyors could be cleaned mainly by wiping them with a cloth, but because of the risk for glass and metal residues in the structures, most maintenance work has to be done by professionals. Finally, the prices for reverse vending machines and their maintenance tend to be rather high compared with the task they fulfill. Prior art RVM's often has belt driven conveyors, as can be seen in publications US 5967330 and WO 9802853. These are fixed constructions that typically need full service stoppage and at least some disassembly for inspection, cleaning and repair. Conveyor belts are oecasionally damaged by glass chips from broken bottles. A broken or malfunctioning belt is usually not repaired, it lias to be changed altogether with a corresponding disassembly of the conveyor as a consequence. Beit conveyors can be said to have all the disadvantages of prior art solutions as explained above. it is also known to use roller conveyors for transportation of consumer goods, A roller conveyor is often used e.g. in warehouses, and it consists of multiple consecutive small rollers in series. Such roller conveyors in general can be either motor driven or inclined gravity conveyors. E.g. in EP Patent No, 1076020 a roller conveyor mechanism is used to erect objects in an upright position. US Patent Application 2011/008002 describes a fixed roller conveyor having an open structure with the driving mechanism right under the rollers. A drawback of such a conventional roller conveyor, especially in the transport of lightweight goods, is that ensuring engagement of a driving belt with all the rollers along the conveyor constitutes a complex task. As a rule, in order to work, such mechanisms include

pneumatic ally or electrically operated parts. Moreover, the belt is not readily accessible making accessing, lifting and lowering selected portions of it for inspection, maintenance or repair work involves long stoppages of the entire roller conveyor and of the transport line. US Patent No. 5211281 describes a modular conveyor where each module has its own motor and a complicated sensory system for starting and stopping a module system should a monitor system so require. These prior art roller conveyors are used for a specific purpose (erecting an object) where belt conveyors cannot be used for technical reasons, or for large or sensitive products. Known roller conveyors are not optimized for durability in harsh conditions, cleaning and maintenance as required in a RVM as described above.

It is therefore an object of the present invention to create an improved roller con veyor, which would increase the functioning and fluency of reverse vending sen-ices in retail stores, greatly improve serviceability and cleaning of RVM's and thus decrease their life-cycle costs, and increase the reliability and usability of RVM's also as seen from a consumer's point of view.

The inventive roller conveyor for advancement of discrete articles along a predetermined path includes

- a support frame structure extending in the direction of said path and essentially defining the same:

- a plurality of roller conveying modules supported by said frame structure and placed successively along said path, each of said modules comprising a set of mutually spaced rollers extending transversely to the direction of said path,

- at least one endless element supported by said frame structure and driven along a track beneath the rollers and frietionally engaging the rollers of the modul es defining said path, - at least one quick-release means to fasten and release each module to and from said support frame structure- According to a preferred embodiment of the inventive roller conveyor die quick-release means is a latch mechanism situated on both sides of said conveying module. Preferably the conveying modules are also interchangeable with each other, and the rollers made of an easily washable solid material.

Preferably, a second quick-release means includes one or several latch mechanisms on one side of said guiding and support structures, and hinge means on die other side of said structures, According to a preferred embodiment of the inventive roller conveyor, die guiding structure includes at least a second gate and actuator associated with said second gate for ejecting an article out from its track on said roller conveyor in response to a signal received from said control unit of said conveyor.

Furthermore, an inventive roller conveyor may include means for adjusting the vertical distance between the rollers with respect to the driven element. The invention also concerns a reverse vending machine having a roller conveyor as described above, The reverse vending machine includes;

- receiving means arranged to receive an input of containers :

- identification means 3) for identification of said containers;

- a first gate and actuator associated with said first gate to make a first diversion of said containers in response to a container identification signal received from a control unit of the reverse vending machine;

- an elongated guiding structure placed on top of said roller conveyor, said guiding structure including at least one side guiding means to keep the containers on track on die roller conveyor;

- at least one second gate and actuator associated with said second gate for diverting a container from its path and out from said roller conveyor m response to said identification signal received from said control unit of the reverse vending machine.

According to a preferred embodiment of the inventive reverse vending machine, at least one further quick-release means is provided to enable lifting of said guiding straeture from the support frame structure of said roller conveyor. Preferably the quick-release means includes one or several latch mechanisms on one side of the guiding and support frame structures, and hinge means on the other side. The invention is hereinafter described detail by means of example and by making reference to the attached drawings, where:

Fig. 1 shows in perspective a general overview of a Reverse Vending Machine to which a roller conveyor according to the invention has been fitted; Fig. 2a shows a schematic overview of a roller conveyor according to the present invention;

Fig. 2b shows a schematic view⁷ of a roller conveyor according to one embodiment of the in vention;

Fig. 2c shows a schematic view of a roller conveyor according to another embodiment of the invention;

Fig. 3 shows an inventive roller conveyor module in more detail;

Fig. 4 shows details of the drive and quick-release mechanisms of the roller conveyor according to the present invention;

Fig. 5 shows the inventive roller conveyor with its guiding structure in service position.

A typical Reverse Vending Machines (RVM) processes empty bottles and cans in the following manner: The user inputs the container to a input tunnel 1, and the container is stopped at a first gate 2 for identification. Immediately after the input tunnel is an identification unit 3, which consists of a light source on the left side of the input tunnel I that transmits collimated or polarized light, and on the opposite side across the slope or track where the container is stopped, there is a camera. The light sources and the camera are not part of the present invention, so they are described here for reference only.

The mam difficulty in the recognition of beverage containers is being able to detect transparent containers. By using collimated light, i.e. light which has parallel "rays" of light, one can with Fresnel lenses create an undistorted silhouette of a container. Another alternative is to use a polarized light source and have polarizer filter on the camera. Then clear silhouette pictures of also transparent containers can be taken. This is because a transparent container will allow background light to pass through it, which mixes the polarization of the background light and thus allows one to see the transparent object as white object against black background, which in reality is a transparent object against a white background. In any case, each type of container has to be added "manually'^" to a recognition database of the control unit of the RVM. The silhouettes thus obtained are compared for match and identification in the RVM control unit, and an article identification signal generated will determine the downstream route and treatment of the can or bottle. The camera system is assisted by several barcode readers organized in a layout thai enables reading the barcodes from quite an extensive area on the container surface. Usually the track leading from the input tunnel 1 to the first gate 2 consists of two roiatable cylinders that are rotating the container if needed; i.e. if the barcode cannot be immediately found. If the container is not recognized or unacceptable, the first gate 2 guides it to e.g. a gravity roller conveyor to a rejected containers slot 4. The user can then either retry inputting the container, or leave the container to the rejected slot. An identified container continues on to the conveyor 5, on which secondary gates 6-9 are organized in the appropriate way in order for the bottle to pass through to the relevant exit path from the conveyor. These exit paths may be e.g.

aluminum containers 6, PET containers 7, reusable glass containers 8 and recyclable glass 9. The various gates are actuated to eject an article out frost! its track in response to a signal received from a control unit of the RVM machine. There are polarized light sensors (not shown) on the conveyor for sensing the containers when they arrive to a gate.

The con vey or 5 itself is roughly 300mm wide, and can have two ianes for the containers. The reason for this is that the containers that are crushed or compacted (PET and aluminum) are separated from glass into different lanes to decrease the chances that a wrong kind of container would go into a crusher and e.g. jam it. The first gate 2 on the conveyor divides the containers to the two different lanes immediately after they are identified on the recognition unit making the chance for mistakes in the separation smaller.

Referring now to Fig. 2a, an inventive and easily maintainable modular roller conveyor 10 for a harsh and dirty environment i s shown. The conveyor consists of a series of 300 mm wide stainless steel roller modules 12, each earning a dozen of mutually spaced stainless steel rollers 13, extending transversely to the. transport direction of the conveyor. Referring now also to Fig. 3, the individual rollers 13 are made of 020 mm stainless steel tubes with plastic ends 17, stainless steel bearings (not shown) fitted to the plastic ends, and a stainless steel through-axis with female threads in both ends for fastening bolts 18. The rollers are bolted to approx. 300 mm long stainless steel sides 14. to form a module mountable to the conveyor frame 11 with latches. The conveyor frame i 1 consists of a 45 ram x 45 mm aluminum or steel frame for the purpose of easy adjustment and adaptability. The frame 11 is essentially a structure of two parallel rails having a desired length, on which the modules can be mounted and removed, as indicated by arrow H.

In Fig. 2b is shown one embodiment of how to adjust the vertical distance h between the modules 12 and the individual idle rollers 13, with respect to a driven element, i.e. a conveyor belt 19 (see Fig. 4). The conveyor belt 19 travels on short idle rollers 15a, each of which are being supported at the frame i 1 with bolts (not shown) through an oblong aperture l la. The shape of the apertures provides individual height adjustment of each roller 15a, as shown by the arrow h. By adjusting the height of the rollers, at their support point, the contact pressure between the conveyor belt 1.9 and the rollers 13 is adjustable very accurately.

In Fig. 2c is shown another embodiment of the conveyor, where the conveyor belt 19 travels on sliding tracks 15b. Each track has a length corresponding to die length of a module 12, but this is only one option. The length of a ttack 15b may vary and can be as long as the frame 11 itself. The height of each track 15b is adjustable (arrow h) in a similar fashion as the rollers 15a above, at their ends at oblong apertures 1 lb. This provides for a simple and in most cases accurate enough adjustment of the pressure between the conveyor belt. 19 and the rollers 13.

The modular roller conveyor according to the invention has the advantages of being completely a wash- down application, and that the modules are easily detachable from the conveyor drive (see Fig. 4). hi a preferred embodiment, the wash-down requirement results in using stainless steel in the module components, but also robust rubber or plastic rollers can be used. The modules are interchangeable and washable throughout, and also the individual rollers are removable or maintainable only by unscrewing two hex key bolts .18. Also shown in Fig. 3 is an example of a quick-release mechanism, in this ease a latch 16, fastened to each side 14 of the roller module 12. The modules are thus replaceable extremely easily, and one spare module can thus instantly replace a dirty or a broken roller module. A few spare modules and rollers can affordably be stocked in the store in case of a conveyor failure. As said, the modules are completely wash-down applicable, and therefor can be e.g. thrown into an industrial dishwasher. One aspect of the inventive roller conveyor concept, concerns the roller drive transmission. While this can be handled in a number of ways known in the art, the conveyor is according to one preferred embodiment, of the invention equipped with a tangential drive belt, which is a simple and reliable solution, provided measures are taken to preserve contact between the drive belt and the rollers. Fig. 4 shows the drive system, consisting of a 4,5 Nm DC-motor 22 driving the 16 mm wide conveyor drive belt 19 via a 044 mm pulley 21. Also a polyethylene runner 20 is shown, on which the belt runs below the rollers 13. The upside of the belt 19 which is contact with the rollers 13 is coated with a high-friction surface and the bottom of the belt, sliding against the runner 20, is coated with a low-friction surface, in Fig. 4, die belt 19 driving the rollers 13 is located in the left side of the conveyor rollers; although it is theoretically possible that e g, glass could end up on this belt, it is highly unlikely. The belt travels roughly 50mm to the side from the actual lanes on which the containers are conveyed, and is isolated from the containers by a side wall 23. A roller 13 may also be provided with a groove near the end of it, which would prevent leaked, sticky liquid from getting near the belt drive. it is clear that different kinds of drive mechanisms may be used in the inventive context, such as chain and sprockets, indirect drives with friction rollers between the conveyor rollers, etc. There are however multiple benefits in the inventive concept of having a modular roller conveyor driven with a narrow rubber belt on the other end of the rollers. In known RVMs the conveyors are mainly belt conveyors with either one wider belt of two narrower belts that form a V-shape in which the bottle is conveyed, in these conveyors the problems are that die belts can be easily broken by the shards of glass often seen in the machines, the belts are difficult to keep clean and cleanse when needed, removing or replacing the belt requires an expert maintenance person, and also the structures and guides surrounding the conveyor are difficult to cleanse or detach for cleaning, in Fig. 4 is also shown the quick-release mechanisms, i.e. latches 16 that attach the roller modules 12 to the common frame 11 that hosts the drive mechanism.

Referring now to Figs. 1 and 5, a guiding structure 5 placed on top of the support frame structure i 1 is described, as part of a Reverse Vending Machine according to the present invention. The guiding structure 5 essentially consists of parallel profiles or bars 24 extending in the same direction as the frame structure 11, and placed on top of the roller conveyor 10. In order to form a structure, the parallel bars 2.4 are naturally joined together with end and intermediate cross bars. The structure 5 carries a plurality of guiding plates 25, which keep the containers on their intended track, and also provides mounts for gates 26 and their actuators, in order to direct the containers off the track at desired points along the conveyor 10, see discussion of the gates in relation to Fig. 1.

The roller conveyor is easily divided by a centra! guiding plate in two parallel paths, for example, one path for articles to be recycled, like cans and any glass not. having a deposit value, and another path for glass and plastic bottles to be returned to use. The purpose of having two different paths relates to the different treatment for recycled goods (crushing and/or compression), and that misorted glass often may be broken and it is not desirable to have shards travelling along with containers to be re-used. The guiding plate 25 on the left drive belt 19 side also keeps liquid and dirt away from the belt and the surface of the rollers 13.

As can be seen from fig 5, a second quick-release means enables easy removal or lifting of the guiding structure 5 from the support frame structure 11. Preferably, at least one latch mechanism 2.8 on the left side of the structures 5 and 1 1 , and hinges 27 on the other side of said structures, facilitates easy lifting for cleaning, service and maintenance. Also the gates 26 and the aluminum side guides 25 can be easily detached from the conveyor and the frame e.g. for washing purposes.

It is to be understood thai the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

Reference throughout this specification to "one embodiment" or "an embodiment^"' means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment^'' or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment.

As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art. that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended thai the invention be limited, except as by the claims set forth below.

Claims

1 , A roller conveyor for advancement of discrete articles along a predetermined path, including:

- a support frame structure extending in the direction of said path and essentially defining the same;

- a plurality of roller conveying modules (12) supported by said support frame structure (11) and placed successively along said path, each of said modules comprising a set of mutually spaced rollers (13) extending transversely to die direction of said path,

- at least one endless element (19) supported by said frame structure and driven along a track beneath the rollers (13) and friciionally engaging the rollers of the modules defining said path,

- at least one quick-release means (16) to fasten and release each module to and from said support frame structure.

2. A roller conveyor according to claim L wherein said quick-release means (16) is a latch

mechanism situated on both sides of a roller conveying module (12).

3. A roller conveyor according to claim 1 or 2, wherein said roller conveying modules (12) are interchangeable with each other.

4. A roller conveyor according to any of claims 1 - 3. including means (11a, 1 lb) for adjusting the vertical distance (h) between said rollers (13) with respect to said endless element (19).

5. A roller conveyor according to any of claims 1 - 4, wherein the each roller (13) is interchangeable and made of an easily washable solid material.

6. A reverse vending machine having a roller conveyor according to any of claims I - 5, including:

- receiving means (1) arranged to receive an input of containers;

- identification means (3) for identification of said containers;

- a first gate (2) and actuator associated with said first gate to make a first diversion of said containers in response to a container identification signal received from a control unit of the reverse vending machine;

- an elongated guiding structure (5; 23.25) placed on top of said roller conveyor, said guiding structure mciuding at least one side guiding means (25) to keep the containers on track on the roller conveyor;

- at least one second gate (6-9) and actuator associated with said second gate for diverimg a container from its path and out from said roller conveyor in response to said identification signal received from said control unit of the reverse vending machine.

7, A reverse vending machine according to claim 6, wherein at least one second quick-release means (28) is provided to enable lifting of said guiding structure from the support frame structure (1 1) of said roller conveyor.

8. A reverse vending machine according to claim 7, wherein said second quick-release means (28) includes one or several latch mechanisms on one side of said guiding and support frame structure (11), and hinge means (27) on the other side of said structure.