GB2248755A

GB2248755A - Bite detectors

Info

Publication number: GB2248755A
Application number: GB9022687A
Authority: GB
Inventors: Jurgen Fechner
Original assignee: DAIWA SPORTS Ltd
Current assignee: DAIWA SPORTS Ltd
Priority date: 1990-10-18
Filing date: 1990-10-18
Publication date: 1992-04-22
Anticipated expiration: 2010-10-18
Also published as: GB9022687D0; GB2248755B

Abstract

A bite indicator, for line fishing, including a line movement sensor comprising, a mechanical device 19 engageable with and moveable by linear movement of a line, in use. Electrical sensing means is provided capable of producing a continuously variable signal, representative of such linear line movement, connected to actuate indicator means. The sensing means may include a radiation source D1 arranged for directing radiation to a means 24 for varying the radiation intensity with linear line movement prior to detection by a sensing device TR1. <IMAGE>

Description

ImDrovements in and Relating to Bite Indicators The invention relates to bite indicators for use when line fishing.

A bite indicator is disclosed in United Kingdom Patent Specification No. 1,503,596 in which line movement causes rotation of a pulley for rotating a sensor, producing a signal indicative of the line movement and the rate thereof.

Such arrangement suffers from the disadvantage that wind and wave movement can produce movement of the line, so producing incorrect bite indication.

It is an object of the invention to obviate or mitigate the above disadvantage.

According to the invention there is provided a bite indicator, for line fishing, including a line movement sensor comprising, a mechanical device engageable with and moveable by linear movement of a line, in use, associated with electrical sensing means capable of producing a continuously variable signal, representative of such linear line movement, connected to actuate indicator means.

The sensing means may comprise a radiation source arranged for directing radiation to a means for varying radiation intensity with linear line movement, which may include a polariser, a member of variable optical density or a member having a surface of variable reflectivity, prior to detection by a sensing device.

The mechanical device may comprise at least one roller arranged to be engageable by the line for producing rotation thereof with line movement, the or each roller mounting a disc for rotation therewith such disc comprising the means for varying radiation intensity. In a preferred arrangement a pair of rollers are arranged juxtaposed with their rotational axes parallel, each having a circumferential champher at one end to provide a generally V-shaped line receiving area therebetween.

The electrical sensing means may include an amplifier and a level detector, via which the continuously variable signal is fed, in use, and variable sensitivity means associated therewith, which may comprise means for varying the gain of the amplifier or means for varying the detection level of the level detector.

The bite indicator may form part of a rod support.

The foregoing and further features of the invention may be more readily understood from the following description of some preferred embodiments thereof, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a bite indicator with a rod located thereon, in use; Fig. 2 is a front sectional view of one embodiment of the bite indicator of Fig. 1 on enlarge scale; Figs. 3 and 4 are views similar to Fig. 2 but of alternative embodiments; Fig. 5 is a simple block schematic representation of an electrical, sensing circuit for the bite indicators of Figs.

1 to 4; and Figs. 6A and 6B are more detailed block schematic representations of the sensing circuit of Fig. 5.

Referring now firstly to Fig. 1 of the drawings there is shown a bite indicator 10 which comprises a housing 11 formed with two upstanding portions 12 to provide a generally V-shaped area for locating a rod 13 therein. The housing 11 is located at the top of a bank stick 14 and a weight 15 ensures that the rod's line 16 is located in a slot 17 in housing 11. The housing 11 also has control knobs 18 carried thereon which will be described hereinafter.

Referring now to Fig. 2, the bite indicator 10 is shown on enlarged scale and has a pair of juxtaposed rollers 19 freely rotatably mounted on respective shafts 20, the upper bearings 21 of which allow the shafts 20 to be resiliently urged one towards the other. The upper ends of rollers 19 are formed with circumferentially extending champhers 22 to provide a generally V-shaped area 23 therebetween, for accommodating various line diameters, located adjacent slot 17. A pair of discs 24 are located one on each of shafts 20 for rotation therewith. Each of the discs 24 comprises an optical polariser having continuously varying degrees of opacity over each 1800 thereof. A light emitting diode D1 is located beneath discs 24 and a phototransistor TR1 is located above discs 24 in alignment therewith.

Referring now to Fig. 3 there is shown an alternative embodiment, similar to that of Fig. 2 but having a single roller 19 with a single disc 25 mounted for rotation with shaft 20. In this embodiment the disc 25 comprises a material having continuously varying optical density therearound. Fig. 4 shows an arrangement similar to that of Fig. 3 except that a disc 26 is provided, having a lower surface of continuously varying reflectivity spaced therearound. In this embodiment the diode D1 and phototransistor TR1 are both located beneath the disc 26.

Referring now to Fig. 5 there is shown a simplified block schematic representation of an electrical circuit for the indicator 10. Sensor 27 is connected to a power supply 28 with a switch 51 interposed therebetween. The sensor 27 is connected via an amplifier 29 and a filter 30 to a level detector 31. Outputs from level detector 31 are connected to a visual indicator 32 and an audible indicator 33.

Figs. 6A and 6B show the circuit of Fig. 5 in greater detail. With switch SWl closed and line movement causing rotation of roller(s) 19 and hence disc(s) 24, 25 or 26 a continuously variable light signal is received by phototransistor TR1 from the light emitting diode D1. The signal present at the junction of a resistor R2 and transistor TR1 is directly proportional to the amount of rotation of the discs. An amplifier Al comprises a buffer which reduces the signal impedance. The actual amplifying stage consists of the following components: capacitors C1 and C2, which couple the signal to the amplifier; resistors R5, VR1, capacitor C3, and amplifier A2. These components comprise the amplifier and the filter, with resistors R3 and R4 acting to set a reference voltage which is at half the power supply to allow maximum signal swing.Resistors R6, R7 and R8, amplifiers A3 and A4, and diodes D2 and D3 comprise the comparator or level detector 31. The resistor R7 controls the detection window or level and therefor the sensitivity. There are two ways of adjusting sensitivity: a) keep the detection window of the comparator fixed and make the amplifier gain variable of; b) let the amplifier have a fixed gain but make the detection window variable Resistor R9 and capacitor C4 stretch any very short signals to render them detectable.

Gates N1, N2 and N3, resistors R16, R18, transistor TR3 and diode D7 serve to provide a momentary visual indication and components N6, D4, Rill, C6, N7, D5, N8, R14, R13, D6, C7, R15, TR2, R19 and D8 serve to provide a flashing twenty second visual indication. The audible indication is comprised of the following components: N4, N5, R12, VR2, C8 for a tone generator the frequency of which can be controller via variable resistor VR2. Variable resistor VR3 controls the volume. Transistor TR4 switches a coil L1 in order to boost the 9Volt supply voltage to SOVolts necessary to provide sufficient volume output of the speaker.

Hence, in each of the embodiments shown there is provided a bite indicator in which, the volume, tone and sensitivity can be adjusted by control knobs 18, to reduce or prevent erroneous bit indicating signals from being produced by adverse weather conditions.- Since a continuously variable sensing signal is produced, a considerably greater sensitivity control can be provided.

Claims

1. A bite indicator, for line fishing, including a line movement sensor comprising, a mechanical device engageable with and moveable by linear movement of a line, in use, associated with electrical sensing means capable of producing a continuously variable signal, representative of such linear line movement, connected to actuate indicator means.

2. A bite indicator as claimed in claim 1 wherein the sensing means includes a radiation source arrange for directing radiation to a means for varying the radiation intensity with linear line movement prior to detection by a sensing device.

3. A bite indicator as claimed in claim 2 wherein the means for varying radiation intensity includes a polariser.

4. A bite indicator as claimed in claim 2 or 3 wherein the means for varying radiation intensity includes at least one member of variable optical density.

5. A bite indicator as claimed in claim 2 wherein the means for varying radiation intensity comprises a member having a surface of variable reflectivity.

6. A bite indicator as claimed in any one of claims 2 to 5 inclusive wherein the mechanical device comprises at least one roller arranged to be engageable by the line for producing rotation thereof with line movement, the or each roller mounting a disc for rotation therewith, such disc comprising the means for varying the radiation intensity.

7. A bite indicator as claimed in claim 6 comprising a pair of rollers arranged juxtaposed with their rotational axes parallel, each having a circumferential champher at one end to provide a generally V-shaped line receiving area therebetween.

8. A bite indicator as claimed in any preceding claim wherein the electrical sensing means includes an amplifier and a level detector, via which the continuously variable signal is fed, in use, and variable sensitivity - means associated therewith.

9. A bite indicator as claimed in claim 8, wherein the variable sensitivity means comprises means for varying the gain of the amplifier.

10. A bite indicator as claimed in claim 8 wherein the variable sensitivity means comprises means for varying the detection level of the level detector.

11. A bite indicator as claimed in any preceding claim wherein the mechanical device and electrical sensing means form part of a rod support.

12. A bite indicator substantially as hereinbefore described with reference to the accompanying drawings.