WO1997019591A1

WO1997019591A1 - Improvements to weights and sinkers

Info

Publication number: WO1997019591A1
Application number: PCT/AU1996/000775
Authority: WO
Inventors: Arthur Keith Acworth; Kevin Glen Acworth; Gary Acworth
Original assignee: Arthur Keith Acworth; Kevin Glen Acworth; Gary Acworth
Priority date: 1995-11-30
Filing date: 1996-12-02
Publication date: 1997-06-05
Also published as: CA2239961A1; JP2000509963A

Abstract

A sinker having a relatively dense solid body adapted for retention on a line and a non-toxic barrier material covering at least the external surface of the body. This barrier material is typically a polymer coating, preferably of thickness 100-300 microns. It can be multi-layered and/or multi-coloured.

Description

"IMPROVEMENTS TO WEIGHTS AND SINKERS" -- BACKGROUND OF THE INVENTION — This invention has application to weights such as sinkers for fishing lines and for diving and the like. This invention has particular application to weights formed with a line passage therethrough. Such weights and sinkers will hereinafter be referred to collectively as sinkers.

Large quantities of lead are used to manufacture sinkers, especially for fishing lines and nets and the like and for divers weight belts. Sinkers are often manipulated by hand by users and thus they expose many persons to potential contamination from the dense metal from which they are formed which typically is lead. Furthermore many sinkers, and particularly fishing line sinkers, are lost during use and litter the world's fish habitats. These sinkers constitute a significant contamination of those habitats.

In addition, maintaining a bait adjacent the floor of a habitat being fished by use of a sinker introduces a clearly visible foreign object into the habitat adjacent the bait which may reduce the chance of a fish approaching a bait in the vicinity of the sinker.

-- SUMMARY OF THE INVENTION -- The present invention aims to alleviate at least one of the above disadvantages and to provide sinkers and methods of manufacturing sinkers which will be reliable and efficient in use.

With the foregoing in view, this invention in one aspect resides broadly in a sinker of the type having a relatively dense solid body adapted for retention on a line and characterised in that at least the external surface of the body is covered with a non-toxic barrier material. This barrier material prevents skin contact with the dense material when handling the sinker. This is particularly important if the dense solid body is formed from a toxic material such as lead. However other materials and metals including iron and steel may be used which will benefit from isolation by a barrier coating for safe or clean handling. Such sinkers may be adapted for retention on a line, such as for example, a fishing line, or on a diver's belt, by being deformable to encapsulate a portion of the line or belt or it be may of volute form or be provided with connection means, either integral or attached thereto, such as a non- corrosive eye or the like. In a preferred form the barrier material is a non-toxic coating which covers all exposed surfaces of the sinker so that the dense body material is isolated from interaction with surrounding water.

The barrier material may be in the form of a plastics sheath applied about the sinker but preferably the barrier material is a coating applied to the dense body in liquid or powder form and bonded thereto. The barrier material may be a polymer coating which when cured exhibits properties of chemical resistance and toughness. It may be a polyurethane resin coating or water reducible or one pack epoxy or polyurethane coating. Preferably the barrier coating is a two-pack epoxy resin coating applied directly to the body. However the epoxy coating may be applied to primed body surfaces. A preferred primer is an epoxy compatible etch primer.

It is preferred that the epoxy coating be deposited to a thickness in excess of 100 microns and more preferably the coating is deposited to a thickness in the range of 100 microns to 300 microns. Preferably the sinkers are of solid form provided with a passageway or passageways therethrough and through which a line or belt may be threaded and the passageway( s ) are coated with a non-toxic barrier material which is preferably bonded thereto or which forms part of an encapsulating casing. The barrier coating on the passageway(s) may be the same or a different coating to that on the external surface of the body.

The barrier material coating the body including the passageway(s ) isolates the body material from interaction with surrounding water, especially salt water.

In a further aspect, it is preferred that sinkers of the present invention adapted for use with fishing line be coated with a coloured, or a selection of coloured, barrier material which is selected for camouflaging the presence of a sinker in an underwater fish habitat or in the alternative is coloured to form a fish attractant or to assist the sinkers visibility.

In yet a further aspect, this invention resides broadly a method of providing a barrier coating over the surfaces of metal sinkers formed with a line passage therethrough, the method including:- submerging the sinkers in a coating liquid able to flow into and coat the surface of the passages through the sinkers; arranging the coated sinkers in location means whereby the sinkers are located spaced from one another; spraying the exposed portions of the located sinkers with a barrier material and causing the coating to at least partially cure or harden; engaging complementary location means across the spray painted portions of the sinkers so as to clamp the sinkers between the location means and the complementary location means; inverting the assembly of the location means and the complementary location means such that the sinkers are supported by the complementary location means; removing the primary location means to expose the uncoated portions of the sinkers, and spraying the remaining exposed portions of the sinkers with a barrier material and causing the coating to cure or harden.

The metal sinkers may be sprayed with a barrier material and cured in any suitable manner including powder coating methods. Preferably however the coating process is a spray painting process.

Preferably the sinkers are submerged in a bath of coating liquid whereby the coating liquid will flow into and coat the surface of the passageway through the sinker. However if desired the sinkers could be submerged in an agitated mist, spray or splashes of coating liquid for coating the surface or passageway.

The coating liquid may be of a type which will inhibit the formation of a permanent membrane across small openings. However, where a barrier material is used which may form a membrane-like film across any small opening, the method further includes transporting the sinkers from the submerging process to a treatment station at which any membrane-like film spanning a passageway opening in the sinker is removed. The coating liquid may be a primer and more suitably an etch primer, however it is preferred that the coating liquid is an epoxy liquid and the submerging process is utilised to apply an epoxy coating to the sinker passage ay(s) to a thickness of between 50 microns and 150 microns. In the preferred form the coating liquid is the same as the barrier material and the spraying process is utilised to apply a two- part epoxy barrier coating to external surfaces of the sinker to a thickness in the range of 100 microns to 300 microns.

In a preferred process the sinkers are transported from the submerging process to the drying station across or through removal means which removes the coating from the outer surface of the sinkers while leaving the passageway coating intact. The sinkers in this partly coated condition may be arranged on a tray or the like to enable the passageway coating to cure without the sinkers bonding to one another through the uncured external coating. The final external coating may be spray applied in stages enabling the sinkers to be readily handled for this purpose.

It is also preferred that some or each of the above processes be repeated to ensure full coverage of the exposed metal surfaces of the sinker to an adequate extent.

It is further preferred that draining of excess coating fluid from the passageway and removal of the coating liquid from the exterior surface of the sinkers is accomplished by moving the sinkers retrieved from the submerging process along a defined path wet with solvent whereby the external coating liquid is removed during passage therealong. The floor of the defined path is suitably provided with an absorbent and resilient material wet with the solvent. The wetting could be accomplished for a batch of sinkers or it could be continuously wet to ensure adequate removal of the coating liquid.

Suitably the defined path is a path between parallel rollers arranged with their peripheries in contact with one another. Their lower peripheries may pass through a solvent bed such that wetting is continuous as is removal of coating- contaminated solvent or the solvent may be pumped to the rollers.

In an alternate process draining of the sinkers after submerging is accomplished with the sinker supported on a vibrating screen arranged in the path of an airflow which may be regulated to rupture membranes spanning openings in the sinker and/or to dry the coating.

In a preferred form of spray painting process adapted for round or substantially symmetrical sinkers, the sinkers are passed onto a regularly dimpled, apertured or otherwise configured tray for holding sinkers in spaced apart relationship. Suitably the sinkers are passed through location means for locating one sinker over each dimple or aperture or the like and after spray coating at least the upper half of the sinkers they are engaged with complementary trays for clamping between the trays, inverted and upon removal of the upper dimpled tray are ready for spray coating the previously shielded portions of the sinkers.

Suitably the trays have substantially identical opposed faces whereby the underside of one tray forms the complementary location means for a corresponding tray therebelow. It is also preferred that similar trays of sinkers are processed simultaneously and stacked for the inversion process. In another aspect this invention resides broadly in a method of spray painting the external surfaces of a plurality of small round or regular shaped articles, including: - locating the round or regular shaped articles on a tray configured to locate the articles in spaced attitude to enable one side to be spray coated; spray coating said one side; allowing the partially coated round or regular shaped articles to at least partially cure; clamping the round or regular shaped articles to the tray with a further tray formed with a complementary locating configuration; inverting the clamped trays; removing the uppermost tray, and spray coating the uncoated external surfaces of the round or regular shaped articles.

-- BRIEF DESCRIPTION OF THE DRAWINGS -- In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate typical embodiments of the invention adapted for coating fishing line sinkers and wherein: -

FIG. 1 is a plan view of a preferred form of apparatus; FIG. 2 is an elevational view of the apparatus illustrated in Fig. 1; FIG. 3 collectively illustrates the dip coating apparatus in plan, end and side elevational views; FIG. 4 collectively illustrates the coating removal apparatus in plan, end and side elevational views; FIG. 5 collectively illustrates the drying table apparatus in plan and side elevational views;

FIGS. 6A and 6B illustrate operation of the loading apparatus associated with the drying table; FIG. 7 collectively illustrates the apparatus for inverting loaded trays and its operation; FIG. 8 is a plan view of an alternate form of apparatus; FIG. 9 is an elevational view of the apparatus illustrated in Fig. 8;

— DESCRIPTION OF THE PREFERRED EMBODIMENT — The apparatus 10 illustrated in Figs. 1 to 7 is adapted for coating round sinkers formed with narrow passageways therethrough to enable the sinkers to be threaded onto a line. The apparatus 10 includes a dipping station 11, a primary drying station 12 and a two-pass paint stripping station 14 leading to the drying station 12. As illustrated in Fig. 3, the dipping station 11 incudes a perforated barrel 17 having its lower peripheral portion extending into an epoxy bath 18. The perforated barrel 17 is provided with internal collector fins 19 which are rotated with the barrel 17 about its axis 20 by a belt drive assembly 21 such that sinkers may rest in the bottom of the barrel 17 submerged in the bath 18 awaiting engagement by a collector fin 19.

The fins 19 extend inwardly and in the direction of rotation of the barrel 17 so that, during rotation of the barrel 17, sinkers will be retained behind the collector fins 19 and carried to an upper position from which they will spill onto an outlet chute 22 for delivery to the paint stripping station 14.

At station 14, uncured paint on the outer surfaces of the dipped sinkers will be solvent stripped and discharged to the solvent collection tray 29. In addition any membranes formed at the entrance to the line passages will be removed by contact with the solvent. However the coating in the line passages will remain intact. Thus when the sinkers are discharged from the paint stripping station 14 they will have a relatively clean outer surface so that upon discharge to the drying table 23 they will roll freely thereon and will not contaminate the table 23 with partly cured coating liquid or adhere to one another. As illustrated collectively in Fig. 4 the stripping station 14 comprises a pair of fabric coated rollers 25 arranged with their adjacent peripheries 26 in longitudinal engagement with one another so as to form an inclined V- shaped passage 28 extending from the outlet chute 22 to the table 23.

The lower peripheries of the rollers 25 are confined in a thinners tray 29 which collects contaminated thinners for return to the solvent supply 24 from which thinners are recirculated by pump 16 through spray rails 27 to the upper surfaces of the rollers 25.

The rollers 25 contra-rotate and may be vibrated to ensure that each sinker has substantially all of its coating removed through contact with the wet fabric coated rollers or through contact with one another in the presence of a solvent during passage to the drying table 23. The outer surfaces of the sinkers dry almost immediately upon discharge from the rollers 25 to the drying table where they may reside for curing of the epoxy coating in the passageways.

It will be seen in Fig. 5 that one corner portion 30 of the drying table 23 has a raised apertured loading tray 31 connected by a hinged ramp portion 32 to the lower table portion. Sinkers can be rolled from the table 23 onto this corner portion 30 for passage through and support in any one of the apertures 33. These apertures 33 register with further smaller apertures 34 in a perforated holding tray 35 supported beneath the loading tray 31.

The thickness of the loading tray 31 is substantially equal to the diameter of the sinkers being treated such that the apertures therethrough will be substantially filled by a sinker ensuring ease of removal of the excess sinkers, after filling, back to the table 23.

The holding tray 35 rests upon the table top 37 of the drying table 23 and is clamped thereto by the loading tray 31. This tray 31 is biased by compression springs 38 into its clamped position. The springs 38 extend between the underside of the table 23 and a common end plate 39 on connecting rods 40 which pass through the table to the loading tray 31. It will be seen that each holding tray 35 is square in plan form and is provided with a regular array of apertures 34 therethrough which are formed smaller than the diameter of the sinkers and the apertures 33 in the loading tray 31. Thus the sinkers are located by their lower portions registering with a respective aperture 34.

The clamping pressure can be released by lifting a hand lever 42 as shown in Fig. 6B, which forces the common end plate 39 upwards, freeing the clamping effect and lifting the loading tray 31 clear above the sinkers 36 in the holding tray 35 enabling the holding tray 35 loaded with sinkers to be removed and placed in a spray booth 45 in which the upper surface of the sinkers are spray coated.

The holding tray 35 is supported in the spray booth 45 on a turntable 46 and rotated during painting to ensure a full coverage of at least the upper half of the located sinkers 36. The spray painting may be done with a manual spray gun through the open face 47 of the spray booth 45 with a full rotation of the turntable performed in four equal stages to ensure full coverage of the upper surfaces of the sinkers. Alternatively, fixed spray nozzles may be used if desired. Upon completion of the spraying process the holding trays 35 are loaded into a storage rack 48 for drying of the painted sinkers. The spray booth 45 is provided with an extractor fan 43 below the turntable 46 which discharges filtered air to atmosphere and a provides a downdraft air supply 44 above the tray therein. The spray booth is utilised to spray a two pack epoxy resin paint onto the sinkers at approximately 125 microns per coat.

After curing, an empty holding tray 35, which is suitably formed of metal with aligned apertures is placed over the top of the loaded holding tray 35 in the storage rack 48 and the assembly is removed and placed into a tray invertor assembly 50, as illustrated in Fig. 7, for inversion of the sinkers without dislodgement of the sinkers from registering apertures 34. As shown the invertor assembly 50 has a rectangular carrier frame 51 supporting posts 52 at each corner. The carrier frame 51 is supported by opposed trunnions 59 whereby it may be rotated about a horizontal axis. An opposed pair of the posts 53 are threaded and are rotatable by a common central drive handle 54 through a chain drive 57.

A clamping platen 55 is moveable along the posts and carries threaded collars 56 engaged with the threaded posts 53 which enables the platen 55 to be wound down onto a loaded top holding tray 35t to clamp it against the sinkers located in the bottom holding tray 351 on which the sinkers were painted.

The clamped tray assembly 58 may then be rotated to reverse the positions of the upper and lower holding trays. This procedure is repeated until all trays in the stack are inverted whereupon the inverted sinkers, now positioned with their upper uncoated faces exposed uppermost, may be inserted batch wise on their respective holding trays 35 into the spray booth for complete paint coverage of the sinkers.

After spraying, the coated sinkers are returned to the tray stack for drying. Thus the sinkers obtain a full coating of the two pack epoxy paint in a two-pass painting process and a dipping process. The two-pass painting process may be repeated if desired to increase the thickness of the epoxy coating. The alternate coating apparatus 60 illustrated in Figs. 8 and 9 includes an etching station 61, a primary drying station 62, a spray painting station 63 and a secondary drying station 64 constituted by a roller conveyor 65.

The etching station 61 operates in the same manner as the dipping station 11, however the solution contained in the bath 68 is an epoxy etch. The etch primed sinkers are delivered to a vibrating outlet chute 69 which is perforated and extends to a swing conveyor 70 along which the sinkers may roll to a storage bin 71, or by swinging the conveyor 70 to an alternate position as illustrated at 26, to a drying table 72.

The table 72 is divided into sectors and is rotatable about a vertical central axis for conveying sinkers deposited thereon from the conveyor 70 in divided lots to a work station 30 adjacent the entrance to the conveyor 74 through a spray booth 75 which is similar to the booth 45. An associated tray turner similar to the turner 50 is utilised to enable the sinkers to be painted on both sides.

In use, lead sinkers to be coated are distributed from a loading hopper 76 directly into the barrel 77 where they are submerged in the liquid etching bath 78 which is thinned sufficiently to ensure that all exposed surfaces of the sinker are etch coated, including their line passageways. The collector fins 79 agitate the sinkers in the bottom of the barrel 77 and carry a portion of the sinkers from the bath to an upper location where they are discharged on to the perforated outlet chute 69 which is vibrated to ensure that as the sinkers move along chute to either the storage bin 71 or the drying table 72 excess liquid is drained through the perforations back to the etching bath either directly or from the drip tray.

A blower assembly 80 supported above the external portion of the chute 69 is adapted to force heated air downward onto the sinkers travelling along the chute such that they will be touch dry before discharge into the storage bin 71. The air downdraft created is sufficient to rupture any paint membranes forming across the open ends of the fishing line passageways.

The primed sinkers are held in the bin 71 for at least one hour whereafter they are returned to the barrel 77 for a second etch process. The sinkers after being coated for the second time are, upon discharge diverted along the swing conveyor 70 to the drying table 72 which is divided into sectors to ensure the sinkers are conveyed in batch lots from the swing conveyor to the work station 85.

At that station, sinkers are raked into the trays 86 and located by the dimpling or apertures therein, and then placed onto the conveyor at 74 where they pass through the spraying booth 75 which spray coats the upper exposed surface of the sinkers. The spray booth 75 is provided with an extractor fan 87 below the conveyor which discharges filtered air to atmosphere and a downdraft fan above the trays. The spray booth sprays a two pack epoxy resin paint onto the sinkers at approximately 125 microns per coat. The painted sinkers pass around the conveyor 65 for drying and discharge to a storage location where the trays 88 of painted sinkers are stacked one on top of the other.

Sinkers provided with a non-toxic coating may be manipulated by adults and children without concern about possible contamination and health effects. Furthermore, sinkers may be coated in various colours or with two or more colours for camouflage purposes. In addition, sinkers lost in a fish habitat and coated with an inert material, such as the epoxy resin coating as described above, will not provide an immediate toxic input to the fish habitat. It will of course be realised that while the above has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is defined in the appended claims.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: -

1. A sinker having a relatively dense solid body adapted for retention on a line and a non-toxic barrier material covering at least the external surface of the body.

2. A sinker as claimed in claim 1 and having a body of solid form provided with a line passage therethrough and a non- oxic barrier material coating said passage.

3. A sinker as claimed in claim 2, wherein said non-toxic barrier material encapsulates said body.

4. A sinker as claimed in any one of the preceding claims, wherein said barrier material is a polymer coating which when cured exhibits properties of chemical resistance and toughness.

5. A sinker as claimed in claim 4, wherein said polymer coating is a two-pack epoxy resin coating applied directly to the body.

6. A sinker as claimed in claim 5, wherein said polymer coating is applied to a thickness in the range of 100 microns to 300 microns.

7. A sinker as claimed in any one of the preceding claims, wherein said barrier coating is multi coloured.

8. A method of providing a barrier coating over the surfaces of metal sinkers formed with a line passage therethrough, the method including: - submerging the sinkers in a coating liquid able to flow into and coat the surface of the passages through the sinkers; arranging the coated sinkers in location means whereby the sinkers are located spaced from one another; spraying the exposed portions of the located sinkers with a barrier material and causing the coating to at least partially cure or harden; engaging complementary location means across the spray painted portions of the sinkers so as to clamp the sinkers between the location means and the complementary location means; inverting the assembly of the location means and the complementary location means such that the sinkers are supported by the complementary location means; removing the primary location means to expose the uncoated portions of the sinkers, and spraying the remaining exposed portions of the sinkers with a barrier material and causing the coating to cure or harden.

9. A method of providing a barrier coating as claimed in claim 8, the method further including transporting the sinkers from the submerging process to a treatment station at which any membrane-like film spanning a passageway opening in the sinker is removed.

10. A method of providing a barrier coating as claimed in claim 9, the method further including: - providing an epoxy barrier material liquid bath for the submerging process; transporting the sinkers from the bath across or through removal means which removes the coating from the outer surfaces of the sinkers while leaving the passageway coating intact, and subsequently spray painting the sinkers with the same or a compatible epoxy barrier material liquid to coat the remaining exposed portions of the sinkers.

11. A method of providing a barrier coating as claimed in claim 10, wherein removal of excess coating fluid from the passageway and from the outer surfaces of the sinkers is accomplished by moving the sinkers along a defined path wet with solvent.

12. A method of providing a barrier coating as claimed in claim 11, wherein the defined path is a path between rollers wet with solvent and arranged with their peripheries in contact with one another.

13. A method of providing a barrier coating as claimed in any one of claims 8 to 12, wherein the sinkers to be spray coated are passed onto a tray configured to locate the sinkers in spaced attitude to enable one side to be spray coated whereafter the sinkers are clamped to the tray by a further tray, the trays inverted and the upper tray removed prior to spraying the uncoated external surfaces of the sinkers.

14. A method of providing a barrier coating as claimed in claim 13, wherein the trays have substantially identical opposed faces defining recesses for locating respective sinkers whereby the underside of one tray forms complementary location means for a corresponding tray therebelow.

15. A method of providing a barrier coating as claimed in any one of claims 8 to 14, wherein the bath is an epoxy bath and the submerging process is utilised to apply a two-part epoxy coating to the sinker passageways to a thickness of between 50 microns and 150 microns and the spraying process is utilised to apply a two-part epoxy coating to the external surfaces of the sinkers to a thickness in the range of 100 microns to 300 microns.

16. A method of providing a barrier coating as claimed in any one of claims 8 to 15 for forming a coated sinker as defined in any one of claims 1 to 7.

17. A method of spray painting the external surfaces of a plurality of small round or regular shaped articles, including: - locating the round or regular shaped articles on a tray configured to locate the articles in spaced attitude to enable one side to be spray coated; spray coating said one side; allowing the partially coated round or regular shaped articles to at least partially cure; clamping the round or regular shaped articles to the tray with a further tray formed with a complementary locating configuration; inverting the clamped trays; removing the uppermost tray, and spray coating the uncoated external surfaces of the round or regular shaped articles.