EP3737228A1

EP3737228A1 - Bite detector for recreational fishing

Info

Publication number: EP3737228A1
Application number: EP19701048.1A
Authority: EP
Inventors: Stephen Neil Matthews
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-01-11
Filing date: 2019-01-10
Publication date: 2020-11-18
Also published as: GB202012268D0; WO2019137990A1; GB2584055A

Abstract

A bite alarm for sensing a bite on a fishing line of a fishing rod, and a line tension sensor. The bite alarm comprising: a housing, and a line movement sensor assembly. The line movement sensor assembly comprising: a moveable member, anchored relative to the housing at a first end, and movable relative to the housing at a second end, said member having two edge portions which are offset relative to one another, said edge portions being disposed distal to the first end and arranged such that when a fishing line is disposed in the line movement sensor assembly, opposite sides of the fishing line are in contact with respective edge portions at different points spaced along the length of said line; and a sensor configured to detect movement of the second end of the member relative to the first end.

Description

Bite Detector for Recreational Fishing

Field of invention

The present invention relates to a bite alarm and a line tension assembly.

Background

Bite alarms, and notably electronic bite alarms, are well known in the art and are in common use by anglers, especially when fishing for carp.

Commercially available bite alarms have existed for more than three decades and provide satisfactory performance to able-bodied anglers. Therefore, at present, the features and benefits of bite alarms have changed little, as their performance and flaws are accepted by the majority of healthy and able bodied anglers. However, this is not necessarily the case for anglers with disabilities or chronic illnesses.

Evidence has been actively gathered regarding the experiences of anglers with disabilities or chronic illness, as well as the reasons why (when appropriate) they no longer fish whilst actively wanting to. This evidence was used to develop the bite alarm and line tension assembly discussed herein.

To some businesses and end-users, it may seem odd to have excluded the majority of consumers from the evidence gathering exercise discussed above, and then to generate a design brief based solely on said evidence. However, that was the route followed by the inventor of the bite alarm and line tension assembly discussed herein. As demographics continue to shift towards a more elderly population, and as medical advancements continue to prolong the life spans of those suffering from disabilities or chronic illness, the inventor took the view that those consumers should not be excluded from following their chosen hobby.

Bite alarms known in the art commonly fall into three categories: (i) those which form rod rests (for example those described in GB1503596 and GB2222060), (ii) those which are suspended from the fishing line (for example bobbins), and (iii) those which are attached to or are an integral part of the fishing rod (for example rod tip detectors). Rod rest bite detectors can be further be subdivided into those which detect changes in line movement, and those which detect changes in line tension. Rod-rest bite detectors which detect movement of a fishing line do so by monitoring the translational forwards and backwards motion of fishing line (relative to the fishing reel or the rod tip) as it is actively drawn over the sensor. For example, 10 centimeters of fishing line drawn forwards over the sensor may register as a bite. An exemplary movement based rod- rest bite detector is described in GB 1503596, which describes a bite detector whereby forward and backward translational movement of the fishing line rotates a wheel and rotation of said wheel can be measured by an electronic sensor connected to an alarm indicator, e.g. a buzzer or light. Wheel based sensors have a V profile around their circumference and at the highest point on the wheel the V profile makes contact with the underside surface of line. However, there are several limitations of wheel-based designs such as loss of sensing performance caused by the inherent friction between the trunnions of the wheel and their respective fixtures in the supporting housing, freezing water preventing the free rotation of the wheel, diminishing performance caused by grime transferred from dirty water carried from the line onto the sensing mechanism or wheel rotating mechanism, and the limited resolution of line movement provided by a wheel based design.

GB2222060 replaces the wheel with a solid-state piezoelectric stylus. The stylus has a V shaped profile as its contact point, and makes contact with the underside surface of the line. However, the piezoelectric stylus design has significant limitations. It is necessary to isolate the piezoelectric material from water. The piezoelectric stylus is not suitable for direct contact with the fishing line due to its brittleness, and the inevitable wear of the stylus risks exposing the intercalating metal shimmy of the piezoelectric bimorph which can accidentally cut the fishing line and/or result in a deviation of electrical output from a known input value. Whilst the piezoelectric stylus may be capped with a plastic bifurcated line guide to address this issue, the plastic eventually wears away over time, requiring specialist servicing, and this means that all of the force of a hooked large fish is wholly transmitted directly onto the small brittle piezoelectric stylus which can result in catastrophic failure. Finally, piezoelectric styluses are unable to distinguish between forward and backward direction of movement of a line.

Generally, bite alarms only sense line movement. The few tension based rod-rest bite detectors which have attempted commercial viability either monitor the line for changes in tension or the amount of force being transmitted from the line to the rod and then from the rod to the rod rest bite alarm as described in US2785494. Often line tension designs rely on a mechanical system, most often involving two pivotable members connected together with a pin and held apart by an arrangement of using tensioning screws and helical springs. When the line tension exceeds a threshold value, the mechanism brings together the pivotable members into electrical contact to complete the alarm circuit. However, as the tension threshold value cannot easily be adjusted easily, such alarms only provide one sensitivity setting in the field, or require the use of e.g. screwdrivers. These devices are also suffer from short circuiting when it rains, and are susceptible to corrosion or grime clogging up their rotary pivot joints. None of these devices are able to detect dynamic ranges of tension in real time.

There remains an unmet need to develop a bite detector which is capable of reproducibly detecting dynamic ranges of line tension in real-time, in order to reduce or eliminate false alarms caused by environmental variables such as tidal currents or wind, and herald an era when a bite alarm might only ever generate an alarm when a bite has actually occurred.

SUMMARY OF INVENTION

In a first aspect, the invention provides a bite alarm for sensing a bite on a fishing line of a fishing rod, the bite alarm comprising:

a housing, and

a line movement sensor assembly, the line movement sensor assembly comprising: a moveable member, anchored relative to the housing at a first end, and movable relative to the housing at a second end, said member having two edge portions which are offset relative to one another, said edge portions being disposed distal to the first end and arranged such that when a fishing line is disposed in the line movement sensor assembly, opposite sides of the fishing line are in contact with respective edge portions at different points spaced along the length of said line; and

a sensor configured to detect movement of the second end of the member relative to the first end.

Optional features of the invention will now be set out. These are applicable singly or in any combination with any aspect of the invention.

The edge portions may provide a range of contacting points where opposing sides of the fishing line are in contact with respective edge portions. The edge portions may be fixed relative to one another. The line movement sensor may be disposed below the rest, such that when a fishing rod having the fishing line is placed on the rest, the fishing line is located in the line movement sensor assembly

The bite alarm may further include an alarm configured, in response to said sensor detecting movement of the second end of the member, generate an alarm.

The bite alarm may further include circuitry used to power the sensors and to process the sensor signals, and/or devices to provide alerts such as LEDs, audio and wireless communications units.

The edge portions may be formed from a single piece of wire. Advantageously, this may simplify manufacture.

The moveable member may have a cavity with which the edge portions are aligned. Said another way, the moveable member may bifurcate partway along its length to provide one or more tines. The space between the tines may provide the cavity with which both edge portions are aligned. By aligned, it may be meant that the edge portions both lie within a common plane passing through the cavity. This common plane may extend in a direction generally aligned with the fishing line (when present in the sensor). Said yet another way, the moveable member may comprise one or more upwardly projecting arms and the edge portions may be aligned with the space between said arms. The common plane may be described by a vector which extends perpendicular to the direction of the line, and which may also be perpendicular to the direction in which the upwardly projecting arms project.

The movable member may be a flexible electronic circuit. The movable member may be a plate, and in some examples a metal plate.

The housing may include one or more line guides arranged such that when a fishing line is introduced into the bite alarm it is directed to contact the edge portions. The line guides may each provide a lower edge, so as to limit movement of the fishing line in a direction towards the first end. The line guides may be made of hardwearing materials such as ceramic and/or metal.

The moveable member, which may be referred to as a stylus, may be formed from a resilient material. This means that when line contacted by the edge portions starts to move, the frictional grip between the moveable member and line moves the moveable member with the line until a position where the force provided by the resilient nature of the moveable member is greater than the frictional force holding the edges against the line and so the moveable member slips in the opposite direction to the direction of line travel and automatically moves back towards its natural resting position. As the line continues to move this cyclical behaviour can repeat and continue in an oscillatory fashion until either line movement ceases of the rod is removed from the bite alarm.

The main body of moveable member can be manufactured from a wide variety of materials, such as metals, composites, plastics, laminates. In some embodiments, the moveable member takes the form of a planar sheet design. In other embodiments, the moveable member will take other forms such as being a wireform itself either having a repeating structure such as helical spring or being folded into either a complex 2D or 3D structure.

In some embodiments, the moveable member includes or is formed from a cantilever. This enables volumetric miniaturization of the moveable member.

The moveable member may provide one or more pair of substantially vertical edges which, in use, are capable of simultaneously making contact with opposite sides of the fishing line.

The edges which make contact with the line which are used to detect line motion may lie upon substantially vertical planes. Vertical edge contact locations permit the pendulum like movement of moveable member to occur whilst maintaining contact with the line by providing“contact expanses”, which accommodate contact points which have dynamically changing positions along the edge. If contact is made along non-substantially vertical edges, the moveable member is unable to initiate a pendulum like action because the non- substantially vertical edges when viewed from the coronal plane inevitably cross at a specific height and thereby do not provide a contact expanse but a discrete contact point at a constant height which reduces the moveable member oscillating nature because the set height of the line restricts the undulating contact point of the moveable member’s return stroke.

In a preferred embodiment, the axes of all vertical edges present in the line movement sensor assembly are placed upon a sagittal plane, i.e. one passing from the front to the back of the device, but this does not need to be the case. Vertical edges placed onto separate planes which are either on the sagittal plane, or offset from it, function well and in certain circumstances provide improved sensing performance.

In some embodiments, the moveable member comprises a line guide, which ensure that the fishing line makes contact with the one or more pair of substantially vertical edges on opposite sides of the fishing line. In some embodiments, the line guide comprises the one or more pairs of substantially vertical edges.

The moveable member and line guide can be constructed from a single part.

The surface of the line guide may be modified to either decrease or increase the amount of friction between said line guide through blasting with abrasives, electropolishing, and/or erosion with corrosive substances.

The sensor assembly according to the present aspect does not need to make intermittent contact with the underside surface of the line because it rather makes contact with alternative offset sides of the line. This provides a grip in a fashion similar to how a rope can slip between a thumb and forefinger. Because of the double contact arrangement being present on a single stylus one or two parts of the loaded line are always in constant contact with the sensor assembly and therefore a continuous signal is generated for as long as the line continues to move.

The slot, which is preferably able to laterally deflect line, loads line onto the opposite sides of two vertical edges so that the line between the two vertical edges is laterally deflected into a slalom-style path with edge contact points which are offset along the length of the line. This enables the line movement sensor assembly to handle lines of different diameters, different materials and compositions (such as braid or monofilament) and act in an oscillatory fashion as long as the line continues to move.

The movement sensor assembly comprises one or more electronic sensing means capable of detecting movement in order to detect movement of the moveable member and, hence, line movement. In some embodiments, the sensing means is a strain gauge. In other embodiments, the sensing means is a MEMs accelerometer. Preferably, the sensing means assembly comprises a first sensing means attached to the moveable member and sensing means fixed to a part of bite alarm not influenced by line movement, such as the printed circuit board. This means signal analysis can be used to decipher forwards and backwards line movement and also provide the opportunity to deduct unwanted environmental signal noise.

In other embodiments, the sensing means assembly comprises a magnet fitted to the moveable member and a magnetic sensor, such as a Hall Effect sensor, mounted to a part of bite alarm not influenced by line movement, so that when the moveable member moves the magnet changes its distance from the fixed location of the magnetic sensing device.

In some embodiments, the movement sensor assembly comprises a resilient member located at the extreme end of the moveable member stroke such that these members can provide additional kinetic energy to rebound the moveable member if the moveable member extends to or enters within the boundaries of said resilient members, and assist it return journey towards its original resting position. This allows the bite alarm to be used under extreme conditions such as sea fishing with heavy weights or excessively taught fishing lines caused by a large hooked fish where the tension within the line imparts excessive frictional forces which can overwhelm the resilient nature of the moveable member and thus its ability to overcome its bound engagement with the moving line. In some embodiments, the resilient members are helical springs, wireform springs, deformable plastic protrusions, or are formed of resilient materials such as silicone rubber.

In some embodiments, the loading of the line onto the moveable member (i.e. between the moveable member’s offset vertical edges) can optionally be assisted by a line loading guide. In some embodiments, when the rod is lowered onto the bite alarm, the line loading guide intentionally causes lateral deflection in said fishing line from a relatively straight path to a deflected path which slaloms the line around the opposite edges of the moveable member’s offset vertical edges which provides an automatic loading of the line onto the sensor.

In some embodiments, the line loading guide is part of the moveable member. In other embodiments, the line loading guide is separate from the moveable member. The moveable member and line loading guide, and/or the line movement guide and line loading guide, may optionally be constructed from a single part.

In some embodiments, the line loading guide is a slit which permits the fishing line associated with the supported rod access to the sensor. Ideally the bottom edge of the slit prevents further downwards travel of the line so that the line becomes rested at a preferred horizontal level relative to the moveable member’s vertical edges and it is this position which is optimum for the sensor monitoring of line movement. In some embodiments, the inner edges of the slit comprise recessed grooves which can receive and secure wireform line loading guides. In some embodiments, the slit is profiled such as to deflect a line.

In some embodiments, the line loading guide is a wireform. The wireform may be made from solid wire. Alternatively, a hollow tubing can be used. Hollow tubing allows non-radii bends to be formed during tooling, and radii can be flattened in a post-process using sharp right- angled jigs. This allows the production of a wireform with sharp corners.

In some embodiments, the bite alarm comprises a pair of case inserts which cooperate to form a slit line loading guide along their interface. This prevents the need for complex injection mould tooling which opens and shuts along the sagittal plane, which is

perpendicular to the tool action for the front and back case parts. In some embodiments, the inner faces of the case inserts comprise recessed grooves which can receive and secure wireform line loading guides. In some embodiments, the case inserts comprise reciprocal tongues and grooves through which the case inserts can be joined so as to cooperate.

Additionally or alternatively, adhesives can be used to join the case inserts, preferably in combination with specifically designed gaps between mating surfaces functioning as microfluidic adhesive dispersal channels and injection points.

Although a wire guide supported within a slitted compartment is described herein, apart from providing physical protection from environmental noise such as wind or rain drops striking the cantilever or accidental contact of the cantilever with a foreign object there is no need for the plastic compartment to exist and therefore line guiding can be purely achieved with a line guide capable of maintaining its own shape.

In some embodiments, drainage holes can be integrated into the bodies of parts which complete the compartmented slit, or voids can be created where one part meets another, so that these one or more openings can form exit channels for water which has collected within the slitted compartment.

The bite alarm of the present invention is applicable to rod rest styled bite alarms. However, the bite alarm as described herein may additionally or alternatively be mounted within a bobbin. A bite alarm according to the invention may therefore comprise a housing located beneath a fishing rod. In some embodiments, the bite alarm comprises an anchorage means. The anchorage means may comprise hinged rigid arm, which provides a rigid fixture. This prevents the bobbin twisting on the line caused by the forces imposed upon it by the slalom profile between the two edges of the line guide. The anchorage means may comprise a flexible cord is another solution. The anchorage means may be anchored at one end to a fishing rod, a bank stick, a bite detector, or any other static anchorage point.

In some embodiments, the bite alarm comprises a limiter to restrain line movement above a certain point. This may be configured so as to prevent line movement above and out of the line guide. The bite alarm may further comprise a limiter to restrain line movement below a certain point. This may be configured so as to prevent line movement below and out of the line guide. The limiters may be reversible restraints, e.g. clips, such that when the rod is lifted from its resting position the line is released from the restraint.

In some embodiments, the bite alarm is provided as a bobbin and further comprises a further electronic sensing means configured so as to detect vertical movement of the bobbin (i.e. movement caused by changes in line tension). The further electronic sensing means may comprise a micro-electro-mechanical system (MEMS) device such as a MEMS

accelerometer or MEMS inclinometer. In some embodiments the bite alarm may process signals from the line movement sensor assembly and the further electronic sensing means to produce an alarm in response to output from one or both sensors.

In a second aspect, the invention provides a line tension sensor, operable to sense the tension of a fishing line, comprising:

a housing, which in use bears the weight of a fishing rod;

a mount, for supporting the housing;

a support coupled between the mount and the housing and on which the housing rests; and

a sensor, configured to sense a deformation of the support due to a force applied to the mount by the housing and thereby sense a tension in a fishing line of the fishing rod.

The support may be provided as a support plate. The support may extend in a direction substantially perpendicular to a line joining the mount and the housing. The sensor may sense a range of changes in the force applied to the mount by the housing.

The mount may or may be attachable to a bank stick.

The line tension sensor may further comprise an alarm configured to generate an alarm when a sensed tension in the fishing line of the fishing rod indicates a bite.

When the rod is supported by the bite alarm, the rod’s weight and/or combined weight of reel, line etc. cause physical deformation of all structural components which are involved with transmitting the force to the ground. When the system becomes static, the deformation is constant but any changes to the system will result in a change in deformation.

For example if additional load, for example wind or tidal forces or a fish pulling on a taught line are applied to the static deformed state the system will become dynamic and additional deformation will occur. Alternatively, if the rod is removed from the system deformation will be reversed and the system will return to its original state. Such a sensor system could be defined as a set of highly sensitive digital scales monitoring the dynamic change of weight being applied to them.

For example the line tension sensor assembly is able to detect the mass of the supported fishing rod and its associated items, such as the casting reel and the amount of line on its spool. It is able to detect an increase in force submitted to the rod from a taught line once a bite occurs and a hooked fish moves away from the rod, and also a decrease in force as the line tension decreases as a hooked fish swims towards the rod or the hook is dislodged from its resting position. It is also able to sense changing environmental parameters such as water currents or wind.

The support plate may be configured to flex by any degree so long as it may be detected by the sensing means in response to a fish bite. In some embodiments, the support plate is configured such that the degree of flexibility is low, such that the flexion in response to a fish bite is barely perceivable or totally unperceivable to the user. The flexibility of the plate and sensitivity of the sensor may be selected so that the signal produced by a fish bite is close to the limit of the resolution of the sensor. This limited flexing means that when a strong fish bite occurs the flexing does not cause the rod to tilt the bite alarm, which might cause the rod to become unseated from the bite alarm and be lost. A bolt, which can be used to secure the support to a bank stick, may be unitary with the support. That is to say, the support and bolt may be formed as a single part, e.g. moulded from plastic (preferably glass filled nylon). The bolt may include one or more through holes to allow screws or other fixings to secure the line tension sensor to an object (for example, a fishing boat or kayak). These through holes may extend through the bolt in a direction generally aligned with the fishing rod (when held in the housing).

The novel line tension sensor advantageously provides a system where deformation in the support occur on such a small level that no significant change of angle occurs for the housing even under extreme load. This is important because this allows a supported rod to be is horizontally secured on a bite alarm.

Horizontally supporting rods may be advantageous as it allows the rod tip to be held closer to the water.

Furthermore, having the sensor located on a mount which supports a rod-bearing housing in a horizontal support arrangement means that the rod is vertically further from the sensor.

This means that when torsional forces are applied from the rod to the bite alarm this increased distance is able to inherently amplify the signal, and therefore lower cost electronics can be used to measure the surface deformation.

Locating the sensor on a mount which acts as a support for the housing of a bite alarm which supports a fishing rod in the horizontal position also means it can be more easily integrated into an existing bite alarm case. This is important because location of the sensor at other locations would mean that the case needs to move and that means dividing the case into articulated parts which means more expensive tooling, more components, greater assembly costs, higher chance of mechanical failure and ultimately a more expensive product. Placing the sensor on a mount which supports the case also means that rain, condensation, sea spray, etc. will collect and, due to gravity, run down the outside surface of the product and then drip away. This avoids yet another drawback of the articulated case, and avoids the need for complex sealing whilst permitting movement

Locating the sensor on a mount which supports the housing bearing the weight of a fishing rod means that the weight of the rod and the force being transmitted from the line to the rod is what is being measured. This is important because measuring line tension in this way has a linear profile whereas line tension measurements made directly from contact with the fishing line are non-reproducible and are sporadic and irregular because when the fishing line travels through the eyes of the rod the eyes act like ratchets meaning there is no smooth correlation between line tension and the force the line exerts on the sensor. In contrast, line tension measurements made from the force being transmitted from the line to the rod are smooth and show correlation between line tension and the force the line exerts on the sensor.

In some embodiments, the electronic sensing means is a strain gauge. In some

embodiments, the line tension assembly comprises multiple strain gauges at multiple points distributed across the plate. This allows a more complex picture of the flexion in the plate to be obtained which can be used to distinguish between fish bites and changes in tension caused by environmental factors, based on their strain profile.

In some embodiments, the electronic sensing means is capable of dynamic sensing. This may be understood in contrast to static sensing, where the sensor is only able to detect a binary state above and below a given threshold. For example, a static sensor may be configured so that bending a mount by a specified value brings two metal terminals into contact to activate an alarm. This provides single activation value which some bites might not trigger. Dynamic sensing provides an ability to monitor an impulse caused by a bite across time, without setting a single activation threshold. In contrast, a dynamic sensor is able to monitor across a range of values. For example, a dynamic sensor may allow a bite to be characterized not only by a single threshold value but by impulse, acceleration, duration, etc. A dynamic sensing ability can be used to eliminate back ground noise such as wind, water currents, or to out background noise caused by trawling lures etc. from moving boats.

In some embodiments, the anchorage means is an adaptor for receiving a bank stick. In some embodiments, the anchorage means is arranged centrally to the support plate.

In some embodiments, the support plate is configured to make contact with and bear the load of the tension assembly towards its distal edges. This increases the lever length of the plate bearing the load of a change in line tension.

In the preferred embodiment, the plate laterally extends from the anchorage means on both sides of the sagittal plane so that it has a symmetrical design and symmetrically bears the load of the rod rest at its far ends.

Alternatively, the plate may have an asymmetrical design whereby the plate extends from the anchorage means only in one lateral direction so that the line tension sensor assembly only bears the load of the rod rest at one end and behaves more like a cantilever only supported at one end.

In some embodiments, the plate comprises one or more cut-out portions in order to increase inherent deformability. In some embodiments, the plate comprises two or more beams. In a preferred embodiment the plate comprises two beams which are connected at their ends by terminal crossbar sections in order to reduce unwanted torsional twist within the plate. In some embodiments, the anchorage means is held between the beams.

In some embodiments, the line tension sensor assembly comprises one or more buffers positioned in contact with the upper and/or the underside of the plate. Preferably, the buffers are in the form of rods and span the distance between the front and rear faces of the bite alarm. These prevent unwanted translational upwards movement of the plate and/or provide securing means between the front and rear case parts. In some embodiments, the buffers are located towards the edges of the plate.

In some embodiments, the electronics permit the function of‘taring’. Due to the sensitivity of strain gauges to detect minuscule rates of deformation, variabilities in the assembly process can unintentionally distort the resting state of the plate and therefore change the baseline reading of one bite alarm to another and this might lead to an additional calibration step which would increase the cost of the product. To overcome this, the electronics can provide an automated taring feature so that irrelevant of what the product’s resting sensor readings are when the product is turned on the readings are automatically adjusted. In some embodiments, the function of‘taring’ allows further functions such as anti-theft alarms or automated mute functions for speakers or wireless transmission breaks between bite alarms or wireless receivers, or automatically resetting sensitivity for dynamic environmental variables such as a change in tide direction or developing rip currents.

The integration of signals from the line movement sensor assembly with those from the line tension sensor assembly allows further discrimination between fish bites and changes caused by environmental factors.

In some embodiments, the bite alarm comprises an adaptor for different sized rods. The adaptor may have the effect of providing an enlarged rest for a fishing rod so as to accommodate rods with larger diameters. The adaptor may have the effect of providing an smaller rest for a fishing rod so as to accommodate rods with smaller diameters. In either case, the adaptor allows the rest to accommodate the rod such that the line is properly loaded into the bite detector. The adaptor may be removeable, for example through cooperation between a screw thread and a threaded receiver on the adaptor and the bite alarm. The adaptor may comprise affixation means for attaching to the rod.

It will be appreciated that the bite alarm of the above-described first aspect may also include a line tension sensor of the above-described second aspect, together with some, all or none of the optional and preferred features of those aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 , is an isometric view of a bite alarm;

Figure 2 is an isometric view of the line movement sensor assembly and case inserts stripped away from all other bite alarm components;

Figure 3A shows the profile of the slit when viewed from the rear face of the bite alarm;

Figure 3B shows the profile of the slit when viewed from above;

Figure 3C shows the profile of the slit when viewed from the front face of the bite alarm;

Figure 4 is an isometric view of the line movement sensor and slit guides stripped away from all other bite alarm components;

Figure 5 is an isometric view of the line contact guide in isolation;

Figure 6 is a side view of the bite alarm line movement sensor being influenced by movement of the fishing line;

Figure 7 is a cross-sectional view of the bite alarm;

Figure 8 shows the use of a strain gauge as the electrical sensor on the stylus;

Figure 9 shows the use of two MEMs sensors in the bite alarm; Figure 10 is an isometric view of the bite alarm without the housing and highlights components related to line tension sensing;

Figure 11 is an isometric view of the line tension sensing system;

Figure 12 is an isometric cross-sectional view of the line tension sensor assembly stripped away from all other bite alarm components;

Figure 13 is a frontal view of the line tension sensor;

Figure 14A shows distortion related to vertical placement of a fishing rod resting on the bite alarm and a second configuration whereby further distortion has taken place due to tightening of the line or a change in dynamic load cause by environmental variables such as wind or tidal forces or by a fish bite or a combination of physical inputs;

Figure 14B shows distortion of the line tension sensor due to external forces being applied from the left side of the bite alarm;

Figure 14C shows distortion of the line tension sensor due to external forces being applied from the right side of the bite alarm; and

Figure 15 is a partial isometric view of a bobbin including the line movement sensor.

Detailed Description and Further Optional Features

Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

Figure 1 shows a bite alarm 1 of the invention having front 3 and back 4 moulded case parts which join together along a coronal or frontal plane of the alarm to form a housing. At the base of the housing is male threaded bolt 67, which provides a mounting means by which the bite alarm 1 may be attached to a bank stick or similar support. Set within the housing are case inserts 16 and 17, which cooperate to form a slit 12 along their interface. A fishing line may be inserted through the open top of slit 12 so as to pass through into the alarm. Extending upwardly from the top of the bite alarm 1 are two support ears 24, which cooperatively form a rest for a fishing rod with a generally“U”-shaped profile. The slit 12 is at the lowermost point of the rest. As a fishing rod is lowered into place (with the line underneath), it is guided by the concave inner faces of the support ears 24 so that, as the rod comes to rest at the bottom of the rest, the fishing line enters through the open top 12A of the slit 12.

The line movement assembly 21 can be seen in further detail in Figure 2, which shows the case inserts 16 and 17 with the front 3 and back 4 moulded case parts removed. The front 12B and rear 12C faces of the slit 12 are also shown aligned at their basemost points before diverging as they approach the top of the case inserts 16 and 17.

The profile of the slit 12 can be seen more clearly in Figures 3A-3C, which show an aligned viewed from the front (Fig. 3C), the top (Fig. 3B) and the back (Fig. 3A) of the bite alarm 1.

In Fig. 3C, the front face 12B of the slit can be seen to have lower and upper vertical regions connected by an angled region. Travelling upwards from the base, the slit begins in the lower vertical centred around the sagittal plane of the bite alarm 1 , travels across the plane during the angled region, and ends in upper vertical regions offset from the sagittal plane.

Turning to Fig. 3A, it can be seen that the rear face 12C of the slit has the same profile as the front 12B. However, whilst the angles and direction can be the same for front 12B and rear 12C faces of the slit, and the respective lower vertical regions of these faces are aligned, the respective upper vertical regions are positioned in opposite sides of the sagittal plane. The front 12B and rear 12C faces of the slit cannot be superimposed upon one another and are chiral in nature. This chirality is clear when the device is viewed from above as in Fig. 3B. The open top 12A of slit 12 has a generally“S-curve” shaped profile, connecting the upper vertical region of the front face 13 with the upper vertical region of the rear 15 face of the slit. The path formed by the open top 12A crosses the sagittal and coronal planes simultaneously.

The effect of this slit profile is such that a taut fishing line inserted through the open top 12A is deflected laterally as it enters the front 12B and back 12C faces at their upper vertical regions. The front and back ends of the line are deflected in opposing directions, resulting in a slalomed profile. As the line travels downward, it passes through the angled regions and returns to a straight profile by the stage it reaches the lower vertical regions. This is important for proper loading into the line movement sensor assembly 21.

Figure 4 shows a section through the alarm down the slit 12 formed by case inserts 16 and 17. The inner edges of the slit 12 are lined by hardwearing wireforms 19 and 20, which sit in receiving grooves 18 in the walls of case inserts 16 and 17. These wireforms protrude partially from the walls of the slit 12 so as to prevent contact of the fishing line with the case inserts 16 and 17 during insertion, and therefore reduce wear.

Sitting between the case inserts 16 and 17, is the movement sensor assembly 21. lt has a stylus 22 with a stem 22A, upwardly projecting from which are upright arms 22B and 22C, separated by a void or cavity 22D. The stylus 22 is formed from a resilient material so that when kinetic forces are applied to its structure it there is an increase in the internal energy (e.g. potential energy) in the stylus causes it to return to its original shape and or position. The arms 22B and 22C have cantilever portions 22GA and 22GB which project laterally from the stylus 22 before bending and once again continuing vertically. This allows the stylus 22 to be miniaturised. The upright arms 22B and 22C house elongate through-holes 22E and 22F respectively, which provide fixture locations for engagement regions 23A and 23B of line contact guide 23.

Figure 5 shows the line contact guide 23 in isolation, with the other components of the device removed. The guide is formed from a single piece of wire bent into a complex shape with 2-fold rotational symmetry when rotated around the longitudinal axis of the bite alarm.

The line contact guide has a series of offset vertical sections. A first vertical section 23D is connected to a second vertical section 23F through first horizontal spacer 23E at their lower ends. The second vertical section 23F is connected to the third vertical section 23G through horizontal apex spacer 23C at their top ends. The third vertical section 23G is connected to a fourth vertical section 23K through second horizontal spacer 23H at their lower ends. The first 23D and fourth 23K vertical sections connect to the engagement regions 23A and 23B respectively at their top ends. The vertical sections are therefore aligned along the sagittal plane and connected to form a rounded“W”-shaped profile. The engagement regions 23A and 23B are bent away from the sagittal plane so as to be offset from the rest of the line contact guide. Each has a squared section of corresponding dimensions to the elongate through-holes 22E and 22F of the stylus.

As a fishing line descends into the slit, the fishing line is deflected laterally by the slit 12 and wireforms 19 and 20 into a slalomed profile at the point of contact with the line guide as described above. It contacts the movement sensor assembly at the apex spacer 23C.

Under the influence of downward pressure and internal tension, the line will move along apex spacer 23C, either towards the front or back of the bite alarm 1. The direction of travel is essentially random, but frontward movement is described by way of example.

Viewed from the front, the line moves along apex spacer 23C towards the viewer so that opposite sides of the fishing line makes contact with the left hand edge of second vertical region 23F and right hand edge of first vertical region 23D. In the event that the fishing line moved towards the rear of 23C, the opposite sides of the fishing line would make contact with the left hand edge of fourth vertical region 23K and the right hand edge of third vertical region 23G.

As the line descends further into the slit 12 and passes from the upper vertical to the angled regions of 12B and 12C, it leaves contact with the edges of the slit and is held solely by the offset pair of vertical regions of the line guide. As the rod makes contact with the bottom of the support rest, the fishing line passes through the aligned lower vertical portions of 12B and 12C and is held in direct contact with the offset pair of vertical regions of the line contact guide, such that each of the paired vertical regions contacts the fishing line on opposite sides. In this way, the line contact guide communicatively connects the fishing line to the movement sensor assembly 21.

The mode of operation through which bite is detected is shown in Figure 6. A fishing line 25 is shown inserted into the slit 12 and is held by the line contact guide 23 as described above.

When a bite occurs, there is movement in the fishing line 25 in the direction indicated by arrow 34. During this initial movement, the frictional grip between line 25 and the line contact guide 23 is greater than the stylus’s 22 resilience to remain in its resting position 32. Due to the fact that the stylus 22 is securely fixed at one end 33 to the bite alarm case (not shown) and frictionally held against the line 25 at the other end 35, the stylus 22 is dragged in the direction of line movement 34 and follows along a generally arcuate path 32A. The arcing 32A of the stylus 22 continues until the force provided by the resilient nature of the stylus 22 exceeds the frictional force between line 25 and the line contact guide 23. At this point the stylus 22 stops moving (at the position indicated as 36), after which the frictional resistance is overcome. The binding contact between line 25 and the line contact guide 23 slips, allowing the stylus 22 to move in a direction 37 which is opposite to that in which the line 25 is traveling and back to towards its natural resting position 32. This continues until the balance of forces flips, at which point the stylus 22 stops again (shown, for instance, at intermediate position 38) and the frictional grip between the line 25 and the line contact guide once again becomes the dominate force. The cycle of motion for the line movement sensor assembly 21 is reset and starts again. The stylus 22 behaves like an inverted pendulum moving in an arced trajectory until either line movement stops or the rod is removed from bite alarm 1.

The oscillatory nature of line movement sensing assembly 21 is made possible by the discovery that vertical edges are required to enable the stylus to continuously move whilst there is line movement. Without vertical edges, the stylus would either cease or be impaired to oscillate after the first stroke in the direction of line travel. This is because vertical edges are able to accommodate dynamically changing points of contact with the line, rather than a discrete contact point at a constant height, and therefore can accommodate the pendulum like movement of the stylus 22. The movement of the stylus 22 is detected by an electrical sensor, and is processed into an alarm signal in response to a bite.

The packaging of the line movement sensor assembly 21 within the bite alarm 1 can be seen in cross sectional view Figure 7. The figure details how the effective length of the stylus and therefore its ability to flex in response to a passing fishing line can be enhanced by an innovative physical form combined with an effective and hermetic fixture method to the main bite alarm body which provides an appropriate conduit for externally positioned sensors.

The stylus’s fixture location 33 is shown on a second portion 46 which is connected to the first portion 47 by an intermediate portion 48 with a curved“bent back” profile. This provides a stress-reduced deformable hinge mechanism, extending the life expectancy of stylus. This also ensures that the space occupied by fixture location 33 is not taken from the length of the stylus which conducts the sensing. Because a longer length of stylus portion able to bend in response to line movement results in a more responsive line movement sensor assembly, the“bent back” fixture location allows the alarm to be miniaturized without compromising sensitivity The stylus at fixture location 33 is fixed with screws 49 to internal face 50 of the case at position 51. Back case 4 has a through hole 51 which provides access to internal compartment 52, which stores the printed circuit board 53, and can provide access for the electrical connections for sensors which are located in the slitted compartment 54. Through hole 51 is positioned behind the stylus region 46 which makes contact with case face 50 so that when the product is assembled the portion of the stylus surface which makes contact with face 50 acts as a protective face plate sandwiched between the stylus 22 and case.

Figure 8 shows an embodiment using a strain gauge 56 as the electrical sensor on the stylus with its electrical wires (not shown) attached to surface 57 of stylus 22. Cutout profiles 57A in the stylus allow further size reduction by permitting a screwdriver, in the assembly process, access to the screws 49 which bind the stylus to the bite alarm 1 within a smaller space.

In the alternative embodiment shown in Figure 9, the electrical sensor uses motion sensors, such as MEMs accelerometers. Two motion sensors are used: the first 58 is attached to the stylus 22 and the second 59 is fixed to a part of bite alarm not influenced by line movement. The use of two sensors means algorithms can be used to decipher forwards and backwards line movement and also provide the opportunity to deduct unwanted environmental signal noise.

An alternative sensing mode not shown would be to substitute the first motion sensor with a magnet fitted to the stylus 22 and the second motion sensor with a magnetic sensor, such as a hall effect sensor, mounted to the printed circuit board 53 so that when the stylus 22 moves the magnet changes its distance from the fixed location of the magnetic sensing device.

Figure 10 shows an isometric view of the bite alarm without the casing and clearly shows wireless antenna 63, control buttons 64, LEDs 65, power switch 65A, 2.5 mm jack 65B, battery 66, male threaded bolt 67. The parts 68 to 73 are part of line tension sensing assembly 74 discussed below, which is fixed to the male threaded bolt 67.

As shown in Figure 1 1 , line tension sensing assembly 74 has plate 68 at the base of the bite alarm 1. The rectangular perimeter of plate 68 is defined by beams 68E, 68F, 68G and 68H. These beams enclose through-holes 68A and 68B, which permit the power switch 65A and female jack connector 65B, unrelated to line tension sensing, to occupy the same space as the place 68B. This enables the size profile of the bite alarm to be reduced. The two long beams 68D and 68G are connected by circular profile 68J. At least one strain gauge 56 is located on beam 68F, and additional strain gauges may be located at corresponding positions on beams 68E, 68G, and 68H (not shown).

Cross sectional view Figure 12 shows the male threaded bolt 67 attached to the circular profile 68J and secured with captive nut 69. Positioned above plate 68 are rods 70A and 70B which span the distance between the front 13 and rear faces 15 of bite alarm 1 and prevent unwanted translational upwards movement of the plate. Positioned below plate 68 are rods 71 A and 71 B. The plate 68 is sandwiched between 70A and 71A at one short end, and 70B and 71 B at the other. The male threaded bolt 67 passes through resilient washer 72, which is sandwiched between nut 73 and the bite alarm case (not shown) so as to fix the threaded bolt to the case with a hermetic seal, and to provide increasing physical resistance to prevent overload of the line tension sensing assembly 74 as increasing line tension loads are applied to bite alarm 1.

The male threaded bolt 67 may be unitary with the plate 68. That is to say, the plate 68 and male threaded bolt 67 may be formed from a single part e.g. moulded from plastic such as glass filled nylon. The bolt may have one or more through holes to allow screws or other fixings to secure the line tension sensor to an object (for example, a fishing boat or kayak). These through holes may extend through the bolt in a direction generally from the front 3 of the bite alarm 1 to the back 4 of the bite alarm.

The operation of line tension sensor assembly can be understood with reference to Figure 13. A fishing rod is placed in the support rest as before. The position of the rods 70 and 71 are towards the extremities of plate 68 and the lengths of objects 70 and 71 which span plate 68 are oriented on planes offset from the sagittal plane. Because the distance 70X between 70 and the male threaded bolt 67 is greater than the distance 71 X between 71 and the male threaded bolt, the plate 68 is more easily able to flex in the direction of distortion caused by loading of forces onto bite alarm 1.

Figure 14A shows an example of the plate 68S flexing in response to the load of a fishing rod being placed on bite alarm 1. The plate is further distorted 68T due to the force transferred from a cast taught line or plate distortion caused by an increase in dynamic load caused by a fish bite (which in this example is co-linear with the sagittal plane of the bite alarm). Figure 14B shows distortion of the plate 68U due to forces from the rod being applied from the left side of the bite alarm, in the case of a fish bite from a non-collinear angle. Similarly, Figure 14C shows distortion of the plate 68V due to forces from the rod being applied from the right side of the bite alarm. This distortion is detected by strain gauges 56, and is processed into an alarm signal in response to a bite. It should be noted that the distortions of the plate are exaggerated for clarity in Figures 14A-14C, and in reality may be substantially smaller in magnitude.

Whilst shown as being connectable to a bank stick style rod rest e.g. one or more stakes in the ground, to which the line tension assembly connects, it is possible to provide the line tension assembly in a tubular rod rest. In this example, a generally elongate tube is provided in which the handle of the fishing rod may sit. The line tension assembly is then provided between the tubular rod rest and the ground, such that the weight of the fishing rod is borne by the line tension assembly. The line tension assembly then functions substantially the same as described above.

Previously, the bite detector has been described as being mountable to a rod rest via one or more threaded connections. In contrast, figure 15 shows an isometric view of the bite detector described herein when installed as a bobbin. The bobbin housing 3 encases the movement sensing means 5 comprising a stylus 6 and line guide 7 are as described previously. The bobbin housing 3 comprises a through slot 8 through which line may be inserted into the line guide 7. Unlike in the rod rest embodiment, the user may manipulate the line to aid deflection into the line guide 7. Once the line is inserted into the line guide 7, the user may engage the line clip so as to restrain upper line movement, preventing the line from being moved above the line guide. This is a reversible restraint i.e. line can be clipped in and when the rod is lifted from its resting position the line can automatically release from the restraint. The bottom of housing slot 8 restrains lower line movement, preventing insertion below the line guide. In this way, the movement of the line is restricted at its upper and lower extremes such that the line does not leave the line guide.

Bobbins are often tethered so that they are not lost. In the example provided the tether 4 is shown as a hinged rigid arm, which provides a rigid fixture prevents the bobbin twisting on the line caused by the forces imposed upon it by the slalom profile between the two edges but a flexible cord is another solution. Once attached, the line is held below the rod under tension by the weight of the bobbin. When a fish bites, line movement is detected by the movement sensing means 5 as described previously. Changes in line tension are reflected by movement of the bobbin relative to the rod, namely vertical movement.

While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

Claims

1. A bite alarm for sensing a bite on a fishing line of a fishing rod, the bite alarm comprising:

a housing, and

2. The bite alarm of claim 1 , wherein the edge portions provide a range of contacting points where opposing sides of the fishing line are in contact with respective edge portions.

3. The bite alarm of claim 1 or claim 2, wherein the edge portions are fixed relative to one another.

4. The bite alarm of any preceding claim, wherein the line movement sensor is disposed below the rest, such that when a fishing rod having the fishing line is placed on the rest, the fishing line is located in the line movement sensor assembly

5. The bite alarm of any preceding claim, further comprising an alarm configured, in response to said sensor detecting movement of the second end of the member, generate an alarm.

6. The bite alarm of any preceding claim, wherein the edge portions are formed from a single piece of wire.

7. The bite alarm of any preceding claim, wherein the edge portions each have a corner, which engages with the line as the line is introduced to the line movement assembly, which is a substantially 90° corner.

8. The bite alarm of any preceding claim, wherein the moveable member has a cavity with which the edge portions are aligned.

9. The bite alarm of any preceding claim, wherein the movable member is a flexible electronic circuit.

10. The bite alarm of any preceding claim, wherein the movable member is a metal plate.

11. The bite alarm of any preceding claim, wherein the housing includes one or more line guides arranged such that when a fishing line is introduced into the bite alarm it is directed to contact the edge portions.

12. The bite alarm of claim 1 1 , wherein the line guides each provide a lower edge, so as to limit movement of the fishing line in a direction towards the first end.

13. A line tension sensor, operable to sense the tension of a fishing line, comprising: a housing, which in use bears the weight of a fishing rod;

a mount, for supporting the housing;

14. The line tension sensor of claim 13, wherein the support is provided as a support plate.

15. The line tension sensor of claim 13 or claim 14, wherein the support extends in a direction substantially perpendicular to a line joining the mount and the housing.

16. The line tension sensor of any of claims 13 - 15, wherein the sensor senses a range of changes in the force applied to the mount by the housing.

17. The line tension sensor of any of claims 13 - 16, wherein the mount is or is attachable to a bank stick.

18. The line tension sensor of any of claims 13 - 17, further comprising an alarm configured to generate an alarm when a sensed tension in the fishing line of the fishing rod indicates a bite.

19. The line tension sensor of any of claims 13 - 18, further comprising a bolt which can be used to secure the support to the bank stick, wherein the bolt includes one or more through holes to allow screws or other fixings to secure the line tension sensor to an object.

20. The bite alarm of any of claims 1-12 further comprising a line tension sensor according to any of claims 13-19.