Large Marine Animal Automatic Release Device for Use with Deep Sea Fishing Gear
20220322649 · 2022-10-13
Assignee
Inventors
- Todd Richard ELLIS (Somersworth, NH, US)
- Chad Mitchell GREENLAW (South Berwick, ME, US)
- Charles J. DONOVAN (Rollinsford, NH, US)
Cpc classification
B63B22/06
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A water pressure-activated end line severing device is configured to be attached to a lobster, crab or snow crab trawl end line and to automatically sever the end line if a large marine animal has snagged, bitten, seized, caught, become entangled with, or otherwise somehow attached itself to that end line. When any large marine animal, such as a whale, snags or becomes entangled in the end line, the normal, instinctive response of the large marine animal is to dive rapidly to a greater depth, which pulls the end line and the device attached to the end line to a greater depth in the water column. As the device descends to a greater depth in the water column, the water pressure exerted against the device rapidly increases. When the water pressure reaches and exceeds a predefined water pressure threshold, a trigger assembly on the device activates a spring-loaded cutter assembly, which forces movement of a cutting blade to sever the part of the end line that passes through an aperture in the device, thereby freeing the large marine animal from the end line and the weight of the lobster or crab trawl.
Claims
1. A device for automatically severing a rope line that ties a marker floating on or near a surface of a body of water to underwater fishing gear located below the surface of the body of water, the device comprising: a cutter assembly comprising an aperture, a rope line latch to fixedly secure a section of the rope line inside the aperture, and a spring-loaded blade assembly, the spring-loaded blade assembly comprising a blade, a blade holder that holds the blade in a position that is directly adjacent to the aperture, a set of loaded springs connected to the blade holder, the set of loaded springs being configured to urge the blade holder and the blade to move in a direction that causes the blade held by the blade holder to pass through the aperture if the load on the set of loaded springs is released, a receiving slot in the blade holder, the receiving slot being configured to receive a first end of a piston rod that, while inserted in the receiving slot prevents movement of the blade holder in said direction and prevents said release of the load on said set of loaded springs; a rope latch pin operable to (i) move the rope line latch into a closed and locked position across the aperture to fixedly secure the section of the rope line inside the aperture, and (ii) move the rope line latch into an open and unlocked position next to the aperture to release the section of the rope line from the aperture; and a trigger assembly, attached to the cutter assembly, the trigger assembly comprising a cylinder and a piston, the piston comprising the piston rod and a piston skirt disposed within an internal chamber of the cylinder, the piston skirt being connected to an opposite end of the piston rod; wherein, if the device passes below a predefined depth in the body of water, a resulting increase in water pressure on the internal chamber of the cylinder will force the piston skirt and the opposite end of the piston rod connected to the piston skirt to move away from the cutter assembly, thereby pulling the first end of the piston rod out of the receiving slot in the blade holder and releasing the load on the set of loaded springs; whereby the releasing of the load on the set of loaded springs immediately causes the blade holder and the blade to move in the direction that causes the blade held by the blade holder to pass through the aperture and sever the section of the rope line secured in the aperture by the rope latch.
2. The device of claim 1, wherein the internal chamber of the cylinder is configured to have a cross-sectional size that is selected so that the increase in water pressure on the internal chamber will cause the piston skirt to pull the first end of the piston rod out of the receiving slot in the cutter assembly when the device passes below the predefined depth in the body of water.
3. The device of claim 1, wherein the load in the set of loaded springs is imparted by compressing a set of coils in the set of loaded springs.
4. The device of claim 1, wherein the load in the set of loaded springs is imparted by stretching a set of coils in the set of loaded springs.
5. The device of claim 1, wherein the set of loaded springs comprises two or more banks of loaded springs.
6. The device of claim 1, wherein the set of loaded springs comprises an inner loaded spring nested inside an outer loaded spring.
7. The device of claim 6, wherein the inner loaded spring has a first central axis that is coextensive with a second central axis of the outer loaded spring.
8. (canceled)
9. The device of claim 1, wherein the underwater fishing gear comprises one or more lobster traps or one or more crab traps.
10. The device of claim 9, wherein the rope line comprises an end line for said one or more lobster traps or said one or more crab traps.
11. The device of claim 1, wherein the marker floating on the surface of the body of water comprises a high flyer or a polyball.
12. The device of claim 1, wherein the predefined depth is between 30 and 50 feet below the surface of the body of water.
13. The device of claim 1, wherein the predefined depth is between 50 and 100 feet below the surface of the body of water.
14. The device of claim 1, wherein the predefined depth is between 100 and 200 feet below the surface of the body of water.
15. The device of claim 1, wherein the predefined depth between 200 and 400 feet below the surface of the body of water.
16. The device of claim 1, wherein the trigger assembly is configured to pull the first end of the piston rod out of the receiving slot of the cutter assembly if the water pressure exerted on the internal chamber of the cylinder exceeds a predefined pressure threshold.
17. The device of claim 16, wherein the predefined pressure threshold is between 25 and 30 psi.
18. The device of claim 16, wherein the predefined pressure threshold is between 35 and 40 psi.
19. The device of claim 16, wherein the predefined pressure threshold is between 60 and 70 psi.
20. The device of claim 1, wherein the cutter assembly further comprises: a top clamshell; and a bottom clamshell; wherein the top clamshell and the bottom clamshell are bolted, screwed or glued together to define an airtight enclosure that encapsulates the spring-loaded blade assembly.
21. The device of claim 1, wherein the trigger assembly is removably attached to the cutter assembly.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention and various aspects, features and advantages thereof are explained in detail below with reference to exemplary, and therefore non-limiting, embodiments and with the aid of the drawings, which constitute a part of this specification and include depictions of the exemplary embodiments. In these drawings:
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0036] An exemplary Todd Device according to embodiments of the present invention will now be described in more detail with reference to the figures. Some of the figures show computer-aided drawings (CAD) of exemplary versions of the Todd Device. Generally speaking, lobster, snow crab and crab trawl end lines have diameters that are typically between about ½ and ⅝ths of an inch. Snow crab trawl end lines are typically ¾ in. or greater in diameter. However, it will be apparent to those skilled in the art and familiar with lobster and crab fishing that embodiments of the Todd Device of the present invention may be beneficially constructed in a variety of different sizes and dimensions, depending on a variety of different factors, including the diameters of the end lines that need to be severed, the type of water body where the device will be used, as well as depths at which the devices are intended to be used. Therefore, it will be apparent that larger or smaller versions of the Todd Device, as well as Todd Devices having larger or smaller subcomponents, may be constructed and beneficially used without departing from the scope and spirit of the invention that is claimed.
[0037] Turning now to the figures,
[0038]
[0039]
[0040]
[0041]
[0042]
[0043] The spring banks 40A and 40B each comprises an inner loaded spring nested inside an outer loaded spring. In some embodiments, the inner loaded spring has a central axis that is coextensive with the central axis of the outer loaded spring. The spring banks 40A and 40B may be reset to the “loaded” position if the Todd Device 1 has been previously activated and the blade 49 has been previously sprung. Consequently, the Todd Device is reusable.
[0044]
[0045] Both the blade holder 45 and the blade handle 48 include a slot 57 configured to receive one end of a piston rod 62 extending from the trigger assembly 10 affixed to the top of the cutter assembly 5. The insertion of the piston rod 62 into the slot 57 of the blade holder 45 and the blade handle 48 prevents the two banks 40A and 40B of nested springs under compression from decompressing, which prevents the blade handle 48 and the blade 49 from snapping forward as a result of the forces applied by the two banks 40A and 4B of nested springs under compression. When the piston rod 62 is retracted from the slot 57, however, the two banks 40A and 40B will rapidly decompress, which causes the blade handle 48 and the blade 49 to snap forward and cut the end line.
[0046]
[0047] When a large marine animal, such as a whale, comes into contact with an end line passing through the Todd Device, the large marine animal will typically dive to a greater depth in the water column. The dive pulls the Todd Device to a greater depth in the water column. As the Todd Device 1 is pulled to a greater depth in the water column, the water pressure exerted on the trigger assembly increases dramatically. The dramatic increase in water pressure on the trigger assembly causes water to pass rapidly through the water inlets 72 and fill the internal chamber 74 of the cylinder 64, which causes the piston skirt 66 to push the air out of the internal chamber 74 of the cylinder 64 through the plug 70. As the air exits the internal chamber 74 of the cylinder 64, the piston skirt 66 rapidly moves toward the plug 70 inside the cylinder 64. When the piston skirt 66 moves rapidly toward the plug 74, it pulls the piston rod 62 along with it, thereby causing the piston rod 62 to retract into the trigger assembly 10 at a rapid rate of speed. The rapid displacement and evacuation of the piston rod 62 out of the blade holder 45 of the cutter assembly 5 releases the compression on the springs in the spring banks 40A and 40B of the cutter assembly 5, which causes the blade holder 45 to snap forward with enough force to cause the blade 49 to snap forward at a high rate of speed. This rapid movement of the blade 49 completely severs the end line passing through the cutter assembly 5, thereby breaking the physical connection between the trawl on the seabed and the polyballs on the surface of the water.
[0048] The trigger assembly 10 typically has an effective useable range of depths between 20 and 1,500 feet. Preferably, the trigger assembly 10 is factory preset to activate at a predefined depth in the water column and has a plus/minus variance of 1.5 to 3.5 meters in terms of release point in the water column. A variety of different sized trigger assemblies 10 may be manufactured to fit the same cutter assembly, depending on the desired predefined activation depth.
[0049] In preferred embodiments, the trigger assembly 10 on the Todd Device 1 can be set to trigger at any depth in the water column deemed to be most appropriate, taking into account presumed characteristics of the marine animals most likely inhabiting the area or fishing zone. The depth of activation is determined by controlling the cross-sectional size of the internal chamber 74 of the cylinder 64 in the trigger assembly 10. More specifically, the predefined depth (i.e., the depth below the surface of the body of water that the trigger assembly will be activated) may be set by controlling the cross-sectional size (i.e., the internal volume) of the internal chamber 74 of the cylinder 64 on the trigger assembly 10. The larger the cross-section of the internal chamber 74 of the cylinder 64 on the trigger assembly 10, the shallower the depth that the water needs to be for trigger assembly 10 to be activated by the water pressure exerted on the internal chamber 74. Conversely, the smaller the cross-sectional size of the internal chamber 74 of the cylinder 64 of the trigger assembly 10, the deeper the depth of the water needs to be for the trigger assembly 10 to be activated. This is because, as compared to a smaller internal chamber, a larger internal chamber will undergo a greater amount of force of water pressure than a smaller internal chamber located at the same depth in the water column.
[0050] For example, in one embodiment of the Todd device 1, wherein the device is intended to automatically sever the rope line at a predefined depth of about 40 feet below the surface of the water, the internal chamber 74 in the cylinder 64 on the trigger assembly 10 should be constructed to have a height of about 22.3 mm (0.878 inches) and an internal diameter of about 61.3 mm (2.4134 inches). However, it will be appreciated by those skilled in the art that a version of the Todd device 1 that is intended to automatically sever the rope line at say, 400, 800 or 1000 feet below the surface of the water will necessarily have relatively smaller internal chambers (and thus smaller cylinders) on their trigger assemblies, depending on the desired activation depths.
[0051] The diameter of the piston skirt in the internal chamber of the cylinder required to trigger the device at a target depth may be calculated as follows:
Required Diameter=Triggering Force/Water Pressure(P.sub.W)at Target Depth,
wherein,
P.sub.W=Water Density*Force of Gravity*Target Depth
[0052] Table 1 below shows, by way of example, the required diameters (calculated in accordance with the above formula) for the piston skirts and internal chambers of the cylinders for seven different desired target depths for one version of the Todd device having a triggering force of 80 lbs. (or 355.8 Newtons) in ocean water having a density of 1.23.6 kg/m.sup.3.
TABLE-US-00001 TABLE 1 Piston Skirt Diameter Calculations Based on Seven Exemplary Desired Target Depths Water Required Piston Desired Pressure at Skirt Area Required Piston Example Target Depth Target Depth (sq inches/ Skirt Diameter No. (feet/meters) (PSI/Pascals) sq millimeters) (inches/meters) 1 100/30.5 44.3/305,753.4 1.804/1163.814 1.516/0.038 2 250/76.2 110.8/764,383.5 0.722/465.5255 0.959/0.024 3 500/152.4 221.7/1,528,767 0.361/232.7627 0.678/0.17 4 800/243.8 354.7/2,446,027 0.225/145.4767 0.536/0.014 5 1200/365.8 .sup. 532/3,669,041 0.150/96.98447 0.437/0.011 6 1500/457.2 .sup. 665/4,586,301 0.120/77.58758 0.391/0.010 7 3000/914.4 1330/9,172,602 0.060/38.79379 0.277/0.007
[0053] Accordingly, in preferred embodiments of the invention, the diameter of the piston skirt on the piston inside the internal chamber of the cylinder 64 on the trigger assembly (and thus the size of the trigger assembly itself) may be selected according to the desired target depth that the user wishes for the trigger assembly 10 to be activated by water pressure to automatically sever the rope line. Moreover, the triggering assemblies and cutter assemblies may be manufactured in a variety of different sizes and configurations, and may be built to be interchangeable based on the particular environment or fishing application. For example, a triggering assembly configured to activate at a particular threshold depth (say, 50 feet) can be removed from the cutter assembly and replaced with a triggering assembly configured to activate at a different threshold depth (say, 250 feet) if the situation calls for it. Alternatively, embodiments of the Todd device of the present invention may be manufactured so that, for safety reasons, end users cannot remove the trigger assemblies from the cutter assemblies, but the trigger assemblies have been pre-selected at the factory, in terms of their size, so that end users can select the Todd device that already has on it a trigger assembly with the appropriate size to activate the cutting assembly at the desired depth.
[0054]
[0055] The Todd Device 1 is configured to be attached to an end line before the end line is placed into the water. This may be accomplished operating the sliding rope latch pin 50 in the cutter assembly 5 to open the rope latch 35 so that a section of the end line may be pushed to the back walls of the aperture 34. After the end line is positioned in the aperture 34, the sliding rope latch pin 50 is operated again to lock the rope latch 35 over the end line, which secures the Todd Device 1 to the end line. Then the end line, the Todd Device 1 and the trawl may be dropped into the water so that the trawl will sink to the sea floor and the end line extends from the sea floor to the surface of the water.
[0056] When a whale (or any other large marine animal), encounters an end line in the water column, and that contact results in the end line being lowered in the water column by approximately five vertical feet the trigger assembly affixed to the top of the cutter assembly of the Todd Device triggers the pin inside the trigger assembly, which simultaneously releases the blade, which, in turn, instantly slices through the end line passing through the aperture in the Todd Device, thus avoiding entanglement of the whale. See
[0057] The Todd Device 1 is “user friendly” in application, i.e., it is not complex, completely safe, and so uncomplicated as to be completely integrated with modern fishing practices. Further still, the Todd Device 1 requires very little additional time to use while lobster or crab fishing. The Todd Device 1 is not anticipated to be very expensive, and should last at least two years in a salt water environment before replacement becomes necessary. It is also anticipated that embodiments of the device will be used in connection with fishing for other sea creatures besides lobsters and crabs. Embodiments of the present invention may be used in any situation involving end lines connected to traps, or any other heavy equipment on the seabed, where those end lines pose a risk to large marine animals
[0058] In some embodiments, the trigger assembly 10 may be constructed primarily from stainless steel, not including the plug 70 and the O-ring 68, which are typically constructed from rubber or plastic material having an acceptable resistance to corrosion from being in salt water. The cutter assembly 5 may be constructed from stainless steel (screws and bolts and nuts) and any molded and rigid polymer material, such as marine grade high-density polyethylene (HDPE), with acceptable resistance to corrosion or degradation in salt water.
[0059] In preferred embodiments, the trigger assembly is removably attached to the cutter assembly so that various sizes and configurations of trigger assemblies may be attached to the same cutter assembly, depending on the circumstances where the device will be deployed. This would permit, for example, suppliers to purchase and stock separate inventories of trigger assemblies and cutter assemblies, and then assemble Todd Devices with differing activation thresholds, depending on the demand.
[0060] While the present invention has been disclosed with reference to certain embodiments, numerous modifications, alterations and changes to the disclosed embodiments are possible without departing from the scope of the present invention, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.