CLAIMS
1. An object separator comprising: a channel for passage of a single object from a source of a plurality of the objects; a first pivotal member at or near the channel inlet, which member can be locked to prevent entry of an additional object while another object is in the channel, wherein the member when locked is prevented from moving inwardly, yet biased towards a rest position; and a second pivotal member that is in physical communication with the first member; and a control circuit that provides a communicative link between the first member and the second member, such that when the distance between the distal ends of the members is greater than the distance separating the pivot points of the members, the first member is locked; and an adjustable timing mechanism that governs the unlocking of the first member.
2. The separator of claim 1, wherein the channel comprises sheets of material forming the walls and the floor of the channel, with the open ends of the channel defining an entry and an exit. 3. The separator of claim 2, wherein the channel has a U-shaped cross section.
4. The separator of claim 3, wherein the channel further comprises guides that extend from the walls or the floor of the channel.
5. The separator of claim 4, wherein the guides are metal plates that are positioned on opposite sides of the channel and extend longitudinally, forming new walls within the channel. 6. The separator of claim 5, wherein the guide plates are adjustable by manual or automatic means.
7. The separator of claim 6, wherein the guide plates extend from the entry to, or exit of, the channel.
8. The separator of claim 1, wherein a pivotal member is a flap or gate. 9. The separator of claim 8, wherein a pivotal member is mounted at the top of the channel, and is biased towards a rest position in which it is normal to the floor of the channel.
10. The separator of claim 9, wherein a gate or flap comprises a metal sheet.
1 1. The separator of claim 1 , wherein the locking of the first member is effected by a brake.
12. The separator of claim 11 , wherein the brake incorporates a clutch mechanism that comprises a one way bearing or clutch bearing that prevents the inward movement of the member upon locking, but allows the movement of the member towards the rest position.
13. The separator of claim 1, wherein physical communication between the first member and the second member is by way of a pivoted rod.
14. The separator of claim 13, wherein the rod acts on a switch that is part of the control circuit such that when the distance between the distal ends of the members is greater than the distance separating the points about which the members pivot, the switch activates the brake which locks the first member. 15. The separator of claim 14, wherein the distance separating the pivots is half the length of the object to be separated.
16. The separator of claim 1, wherein the timing mechanism is integrated into the control circuit and controls the unlocking of the first member.
17. The separator of claim 16, wherein the timing mechanism controls the rate at which an object exits the separator.
18. The separator of claim 1 , wherein the control circuit is a pneumatic circuit.
19. The separator of claim 17, wherein the timing mechanism is a pneumatic timer.
20. The separator of claim 1, wherein the object to be separated is a fish.
21. The separator of claim 1 , wherein the separator acts in concert with a fish stunning apparatus.
22. The separator of claim 7, wherein the distance between opposing guide plates is sufficient to orient a fish along its dorsal-ventral or ventral-dorsal axis.
Date: 1 1 July 2007 |
SEPARATOR FOR FISH OR SIMILAR OBJECTS
TECHNICAL FIELD
The invention described herein relates to an object separator. In particular, the invention relates to an object separator that can act in concert with an automated fish stunning device, although the scope of the invention is not necessarily limited thereto.
BACKGROUND ART
A pneumatically-powered apparatus capable of stunning large numbers of fish in an automated flow through fashion is described in the international application having the number PCT/AU2003/001615 (International Publication No. WO 2004/049810), which is incorporated herein in its entirety by cross reference. A purported aim of the invention described in the foregoing application is to provide a significant commercial advantage to the operators of fisheries, by allowing large numbers of fish to be processed rapidly with minimal manual intervention.
In a preferred embodiment of the PCT/AU2003/001615 invention, the flow through fish stunning apparatus is incorporated into a specially designed table that distributes fish for stunning. The table comprises a reservoir for holding fish and a slide, such that the slide provides a gravity feed for the fish stunning apparatus. During harvesting, fish move from the reservoir down the slide and are presented to the fish stunning apparatus for processing. Under optimal operating conditions, an individual fish enters the apparatus from the slide and is positioned within the apparatus such that its head is placed within striking distance of a pneumatic ram, which upon activation delivers a mortal blow. After the fish has been stunned the floor of the apparatus moves downwardly and the fish is ejected from the apparatus for further processing.
In commercial operation, the preferred embodiment as described above suffers from a number of significant operational inefficiencies. Chief among these are blockages and stunning inefficiencies that result in damage to the fish and concomitant financial loss.
Operational inefficiencies of this kind are directly attributable to the fact that when harvesting, it often transpires that two or more fish are presented to the apparatus head to tail. To circumvent this problem, the operators of fisheries employ laborers to manually control the flow of fish to the apparatus, to ensure that only one fish enters the apparatus at any given time. This represents a significant "bottle neck" in the overall processing of the fish and is therefore an antithesis to the original objective of the apparatus.
It is the aim of the present invention to overcome this limitation by providing an automated means of regulating the flow of fish to the fish stunning apparatus and other like apparatuses, such that only one fish is processed at any given time. This invention will not only circumvent the need for laborious manual input, but ensure greater efficiency in the stunning of fish during processing, resulting in less damage to the fish and concomitant financial gain.
A further aim of the invention is to provide a device that can be used for separating a broad range of objects and that is not limited to merely separating fish.
SUMMARY OF THE INVENTION
In a broad format, the invention provides an object separator comprising: a channel for passage of a single object from a source of a plurality of the objects; a first pivotal member at or near the channel inlet, which member can be locked to prevent entry of an additional object while another object is in the channel, wherein the member when locked is prevented from moving inwardly, yet biased towards a rest position; and a second pivotal member that is in physical communication with the first member; and a control circuit that provides a communicative link between the first member and the second member, such that when the distance between the distal ends of the members is greater than the distance separating the pivot points of the members, the first member is locked; and an adjustable timing mechanism that governs the unlocking of the first member. It will be appreciated that the object separator can be used to separate a wide variety of objects provided that the objects have a shape that can be physically detected by the first and second members, when acting in combination. The separator can therefore be incorporated into numerous production line processes, where a requirement of the process is that only one object is to be processed at any given time.
The separator can also be used to separate a heterogeneous population of objects into homogeneous groups, based on the size of an object of a particular shape. For example, the separator can be used to separate juvenile fish from adult fish. In such an application, the separator not only regulates the flow of fish to a stunning device, but separates juveniles from adults ensuring that only mature fish are stunned.
The separator can further comprise a cover that is pivotally mounted over the channel and typically closed during operation to prevent operator injury.
The channel typically comprises sheets of material forming the walls and the floor of the channel, with the open ends of the channel defining an entry and an exit. Preferably, the channel has a U-shaped cross section, but other suitable cross-sectional shapes can be used. The
channel can be enclosed in a housing or can form the exterior walls and floor of the separator. In the latter case, a cover can be pivotally mounted to the channel. The floor of the channel can comprise a mechanical means for transporting the object along the channel. Alternatively, the walls of the channel comprise a mechanical means for transporting the object along the channel. It will be appreciated by one skilled in the art that any suitable mechanical means can be used for this purpose. For instance the means can be a conveyor comprising a belt or rollers.
The channel can further comprise guides that extend from the walls or the floor of the channel. The guides can comprise a sheet of stainless steel but can comprise any suitable material. Typically the guides help to define the orientation of the object to be separated. Preferably the guides are plates, that are positioned on opposite sides of the channel and extend longitudinally, forming new walls within the channel. Guide plates positioned in this way, are typically adjustable by manual or automatic means. Guides can also extend from the entry to, or exit of, the channel. Preferably, guide plates extending from the entry to the channel, are positioned at an obtuse angle relative to the plane of the channel floor. In a preferred embodiment, guide plates positioned on opposite sides of the channel, as described above, are used to constrict the channel such that, for example, only a single fish oriented along its dorsal-ventral or ventral-dorsal axis can pass through the separator. It will be appreciated that the distance between opposing guide plates — that is, a distance that is sufficient to orient a fish along its dorsal-ventral or ventral-dorsal axis— will depend on the dimensions of the fish to be separated.
The members can take the form of a flap or gate. However, any pivotal member is envisaged, for example a swinging bar or elongated member optionally with a paddle at its distal end. Preferably, a member in the form of a gate or flap comprises a sheet of stainless steel. Rather than comprising a sheet, the flap or gate can comprise a plurality of cross-pieces or a panel of cross-pieces or a panel of mesh material or a grille fixed between a frame. It is also advantageous if the flap is not affected by the flow of any fluid associated with objects as they pass through the channel. For example, fish will generally be carried through the separator by a flow of water.
In one embodiment of the invention, the mounting of the pivotal members is at the top of the channel, and are biased towards a rest position in which it is normal to the floor of the channel.
In other embodiments of the invention, the pivotal members can pivot from either a wall or the floor of the channel. In the case of wall mounted pivotal members, each member can
have an opposed member on the opposite wall such that the members comprise pairs. The members of each pair move in unison and are biased towards the rest position in which the ends of the opposing members of a pair are adjacent to each other.
The locking of the first member is preferably effected by a brake. A preferred brake mechanism will be described below. Typically the brake will incorporate a clutch mechanism that comprises a one way bearing or clutch bearing that prevents the inward movement of the member upon locking, but allows the movement of the member towards the rest position. It will be appreciated that this feature is advantageous when separating objects that have different dimensions. For example, if a first fish has a distance along its dorsal-ventral axis that is greater than a second fish that follows the first into the separator, it is advantageous for the first member to return towards the rest position after being locked so as to prevent the entrance of the second fish into the channel. If this were not the case the first member would be elevated to accommodate the dimensions of the first fish, locked and remain at the elevated position, whereupon the second smaller fish would gain entrance to the channel. The movement of the members, between the actuated position and rest, can be controlled by any suitable means. Means for controlling the movement of the members could include, but is not limited to, pneumatic or mechanical control.
The physical communication between the first and second members typically takes the form of a pivoted rod. This will be explained in greater below. The rod acts on a switch that is part of the control circuit such that when the distance between the distal ends of the members is greater than the distance separating the points around which the members pivot, the switch activates the brake which locks the first member. It will also be appreciated that the distance separating the pivots, will depend on the dimensions of the object to be separated. As a general rule, this will typically be half the length of the object to be separated. It will be appreciated by one of skill in the art that the control circuit providing communication between the members can be operated by any suitable means. Typically, the control circuit is governed by pneumatics, but can also be governed by a combination of mechanical and pneumatic means. Means of this type are advantageous in wet operational environments. The timing mechanism is typically integrated into the control circuit and controls the unlocking of the first member. The adjustable timing mechanism is preferably a pneumatic timer, but other suitable timing mechanisms are envisaged. It will be appreciated that the timing mechanism provides an adjustable means, by which the operator can regulate the rate at which
an object exits the separator. It will also be appreciated that when the separator acts in concert with a downstream process, where a requirement of the process is that only one object is to be processed at any given time, it is advantageous that the objects are presented to the process at an interval that is commensurate with the time taken for the processing of a single object. In a preferred embodiment the separator acts in concert with a fish stunning apparatus. It will be appreciated that fish stunning apparatuses typically have a cycle time of approximately one second. Thus for optimal operation it is preferable that the fish are presented to the apparatus at intervals greater than or equal to one second. It is preferable therefore that the timing mechanism is adjusted such that fish are presented to the stunning apparatus at intervals that are no less than one second apart.
Components of the object separator can be manufactured from any suitable material but are typically manufactured from metals, or plastics where the latter is more appropriate. Preferred metals are non-corrosive, such as stainless steel and brass. Stainless steel components are preferably electro-polished to provide superior corrosion resistance. Objects amenable to separation using the device according to the invention will typically comprise a surface that, when viewed in cross-section, is convex relative to the floor of the channel.
In a particularly preferred embodiment of the invention, the object separator is for separating fish and comprises: a channel further comprising guide plates to orient a fish along its dorsal-ventral axis; a first member that is a gate or flap that is lockable, and is positioned at or near the entrance to the channel, and contacts the fish first, and is pivotally attached at the top of the channel, and pivots inwardly when contacted by a fish, and is biased towards the rest position which is normal to the floor of the channel; and a second member that is a gate or flap, that is pivotally attached at the top of the channel at a preset distance from the first gate or flap, and pivots towards the exit of the channel when contacted with the fish, and is biased towards the rest position which is normal to the floor of the channel, and is connected to the first gate or flap by a pneumatic cylinder; a pneumatic control circuit that provides a communicative link between the first flap or gate and the second gate or flap, such that when the distance between the distal ends of the two gates or flaps is greater than the distance separating the pivots, the pneumatic cylinder activates the brake which locks the first gate or flap.
an adjustable pneumatic timer that is incorporated into the control circuit and effects the unlocking of the first flap or gate after a preset interval.
The object separator can be incorporated into a fish processing line, positioned upstream and acting in concert with, a fish stunning device, that is described in either WO 2004/049810 or WO 2005/000412. Preferably, the separator is integrated into a table similar to that described in WO 2004/049810, and forms part of a slide, that connects a reservoir or pen that holds fish to be processed, to the fish stunning device. In addition, it is preferable that the object separator is located such that the distance between the separator and the stunning device, allows adequate time for the device to process the fish, before the presentation of the same. In order that the invention can be more readily understood and put into practice, one or more preferred embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of the front side of the object separator. Figure 2 is a perspective view of the reverse side of the object separator.
Figure 3 is a perspective view from above showing the brake assembly. Figure 4 is a diagrammatic representation of a locking mechanism which forms part of the control circuit.
Figure 5 is a schematic diagram of the pneumatic control circuit. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring firstly to Figure 1 , there is shown separator 1 comprises a lockable flap 2 which is pivotally mounted across the top of the channel 3, which comprises the separator. Flap 2 can be independently pivoted and is biased towards a rest position in which the flap is normal to the floor of the channel. Guide plates 4 and 5 are provided at the entry to channel 3. The reverse side of separator 1 as visible in Figure 1 is shown in Figure 2. With reference to Figure 2, there is shown separator 1 further comprising flap 6, guide plates 7 and 8, brake assembly 9, locking mechanism 10 and cover 11. Flap 6 is pivotally mounted across the top of channel 3 and can independently pivot and is biased towards the rest position in which the flap is normal to the floor of the channel. Guide plates 7and 8 extend longitudinally along channel 3 and are adjacent to the edges of guide plates 4 and 5 forming a continuous passage within channel 3. Locking mechanism 10 forms an integral part of the control circuit linking flap 2 and flap 6. Cover 11 is pivotally mounted to the top of channel 3 and is typically in the closed position during operation. Figure 2 shows cover 11 in the open position.
Brake assembly 9 is described in greater detail in Figure 3. Referring to Figure 3, Flap 2 has associated therewith a cam clutch 12 which incorporates a disk 13. There is a caliper 14 included in the assembly which when activated acts on the disk to brake the cam clutch housing. When braked, cam clutch 12 prevents pivoting of flap 2 inwardly although it can still return to its rest position. Advantageously, pneumatic rams 15 and 16 are attached to flaps 2 and 6 respectively. Under constant pressure pneumatic rams 15 and 16 aid the return of the flaps to their rest positions.
Locking mechanism 10 is depicted in Figure 4. A rod 17 extends from a pivotal connection on a crank 18 on flap 6 through a supporting sleeve 19. Supporting sleeve 19 is fixed at the end distal flap 2 to a plate 20 which carries a normally closed roller valve 21. Plate 20 is pivotally connected to flap 2. The free end 22 of rod 17 is beveled and with both flaps 2 and 6 in their rest (vertical) positions is near roller 23 of valve 21 but not in contact therewith. However, extension of rod 17 causes beveled end 22 to contact roller 23 thereby actuating valve 21. Actuation of valve 21 can only occur when the distance between the distal end of flap 6 and that of flap 2, is greater than the distance between the two pivot points.
The pneumatic control circuit is depicted in Figure 5. With reference to Figure 5, there is shown flap 2 and 6, roller valve 21, rod 17, brake assembly 9, pneumatic timer 24, pneumatic memory valve 25, air supply 26 and line connectors 27 and 28. One of skilled in the art would be aware of the pneumatic control circuitry to affect operation of the components referred to above. Detail is furthermore given in the present applicants co-pending international application which has been published under the number "WO 2005/089558", the entire content of which is incorporated herein by cross-reference.
The operation of the separator is described in the following paragraphs. a) Prior to admission of a fish, flap 2 is in a lowered vertical position. If the channel is vacant, brake 9 is disengaged and flap 2 is free to rotate inwardly. b) The fish pushes through flap 2 and enters channel 3. After a prescribed distance the fish engages flap 6. As the fish proceeds further through the channel, flap 6 pivots towards the exit of the channel. c) Movement of flap 6 results in the extension of rod 17 which is connected to flap 2. When the distal ends of flap 6 and flap2 are separated by a distance that is greater than the distance separating the two pivot points, the beveled extent of rod 17 engages a normally closed roller valve 21.
d) When rod 17 engages roller valve 21, brake assembly 9 is activated resulting in the locking of flap 2. e) After locking, flap 2 is biased towards the rest position in which flap 2 is normal to the floor of the channel. Bias is achieved by pneumatic ram 16. f) If pneumatic timer 24 is set, flap 2 will be unlocked after a prescribed time.
It will be appreciated by one of skill in the art of pneumatic timing circuitry, that although the separator would separate head to tail fish without the pneumatic timer, the effect of incorporating an adjustable pneumatic timer enables the operator to adjust the time an therefore distance between separated fish. The foregoing embodiments are illustrative only of the principles of the invention, and various modifications and changes will readily occur to those skilled in the art. The invention is capable of being practiced and carried out in various ways and in other embodiments. It is also to be understood that the terminology employed herein is for the purpose of description and should not be regarded as limiting. The term "comprise" and variants of the term such as "comprises" or "comprising" are used herein to denote the inclusion of a stated integer or stated integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required.
Any reference to publications cited in this specification is not an admission that the disclosures constitute common general knowledge in Australia.