GB2222060A - Bite indicator - Google Patents

Abstract

A bite indicator is described comprising a vibratable member mounted for direct contact with a fishing line and piezo- electric element PE for generating an electrical signal in response to vibration of the member. Friction between the member and the fishing line causes the member PE to vibrate in response to line movement and an electronic circuit senses the vibration and produces a sound and/or a flashing light to indicate line movement. The amplitude of vibration is affected by the speed of line movement and the circuit preferably includes a voltage to frequency converter IC2 to indicate the speed of line movement. <IMAGE>

Description

BITE INDICATOR The present invention relates to a bite indicator for use by anglers.

It is known to provide a bite indicator in a fishing rod support, in which the fishing line is arranged to pass over a pulley which rotates as line is drawn out. The rotation of the pulley is sensed magnetically, or by other means, to produce an audible signal. In certain types of angling, for example when fishing for carp, it may take a considerable length of time for fish to take the bait. Anglers therefore use several rods at the same time to improve their chances of success and a bite indicator is of value to such anglers in that it enables several rods to be watched at the same time.

The present invention seeks to provide a bite indicator which can sense line movement but does not make use of a pulley for this purpose.

According to the present invention, there is provided a bite indicator comprising a vibratable member mounted for direct contact with a fishing line and means for generating an electrical signal in response to vibration of the member, friction between the member and the fishing line serving to cause the member to vibrate in response to line movement.

In a preferred embodiment of the invention, the vibratable member is formed by a piezo-electric element.

Such elements are currently available and are used in record player cartridges.

Advantageously, the element is elongate and is resiliently mounted at one end, its other end being fitted with a stylus over which passes the line of which the movement is to be sensed.

As an alternative to a piezo-electric sensing element, one may use a stylus connected to electro-magnetic, moving coil or Hall-effect cartridge or pickup.

There are in existence several bite indicators but the one referred to above and employing a pulley has so far been preferred because it not only indicates that line is being drawn but also the rate of line movement.

In the present invention, the electrical signal produced by the bowing caused by line movement is a noise like signal falling within a well defined bandwidth but its frequency is not a simple function of the speed of line movement. The amplitude of the output signal derived from the stylus, on the other hand, is dependent upon the speed of line movement and consequently may provide an analogue speed indication without further processing.

Preferably, however, the output signal of the cartridge is rectified and the magnitude of the resulting DC signal employed to vary the frequency of an oscillator, thereby enabling an audible sound to be produced of which the frequency rather than amplitude varies with the speed of line movement.

If several rods are being monitored using different bite indicators, it is desirable to be able to determine immediately which indicator has been actuated. To this end, it is desirable for each indicator to provide a visual and an audible indication of line movement and/or for the tone of each indicator be adjustable to permit recognition from the sound alone.

If a light source, such as an LED, is employed for supplying a visible indication of line movement, it is preferred that the light source should remain switched on for a time even after the sound has ceased. Thus if a single burst of sound is heard, it is still possible to determine after the sound has stopped which rod sensed line movement.

In place of a record player like stylus and cartridge, it is possible to use other forms of vibratable member to sense line movement using the same principle of a vibratable member being bowed by the line movement.

Thus the vibratable member may be a taut string analogous to a violin string as opposed to the elongate element mentioned above which in operation is analogous to a musical saw.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a line movement sensing element, and Figure 2 is a circuit diagram of a bite indicator in accordance with the invention.

The outer housing of the bite indicator is not shown in the drawings and can be generally conventional. A box like unit, designed to be secured to a rod support has a V shaped recess in its top surface on which the rod may rest. While the rod is supported in this position, its line may pass over one or two pulleys or guides which serve only to locate the line.

The element within the housing which senses line movement is shown in Figure 1 and comprises a piezoelectric element PE in the form of an elongate rod. One end of the rod is located in a rubber grommet 10 which is in turn received in a hole in the housing of the bite indicator. The other end of the element PE is fitted with a plastics end piece or stylus 12 which just touches the line. In the drawing, the line movement is along a line normal to the paper and the line rests in the notch in the stylus 12. As the stylus is bowed by movement of the line, it vibrates and produces an alternating voltage on its connection lines 14 and 16, the amplitude of the voltage being dependent upon the amplitude of vibration, which in turn depends on the speed of line movement.

The circuit shown in Figure 2 receives a signal from the element PE and produces a series of bleeps of which the repetition frequency varies with the speed of line movement. The circuit has adjustable sensitivity to cope with different weights of line and other relevant factors, so that the repetition frequency at any given speed of line movement can be set by the user. Beyond a certain line speed, the bleeps merge into one continuous tone. The loudness of the sound can be adjusted as can the tone, the latter permitting a user to distinguish by ear the bite indicators of different fishing rods. The circuit also causes a light emitting diode to flash on and off, and the LED remains energised for a short time after line movement has stopped. The circuit includes an extension socket to permit connection to a remote loudspeaker.

In the circuit diagram, numerals with the prefix R, C, TR, VR and IC refer to resistors, capacitors, transistors, variable resistors and integrated circuits, respectively. Values of resistance and capacitance are not given as suitable component values can readily be determined by those skilled in the art. PE represents the piezo-electric sensing element, LED the light emitting diode, ES the extension socket and LS the loudspeaker. The components G1 to G4 are all NAND gates and are in practice all formed as a single integrated circuit.

The principle of operation of the circuit is as follows.

IC1 is a CMOS amplifier, for example a TLC 271, and serves with resistors R1, R2, R3, and capacitors C1 and C2 to amplify the output signal from the sensor PE. The gain of the amplifier is set by the negative feedback through variable resistor VR1.

The signal amplifier can operate in an active and a quiescent mode depending on the bias applied to one the terminals of IC1. The active mode has higher gain and bandwidth but consumes more current. In the illustrated circuit transistor TR1 acts as a mode switch to switch to the quiescent mode in the absence of a sensed signal and to switch back to the active mode after sensing some line movement.

The amplified signal is rectified by diode D1 and smoothed by filter C3, R5 before being supplied as the input to IC2, which is for example a CD 4046. Such an integrated circuit is normally used in phase locked loops but in the present case it acts with capacitor C4 and variable resistor VR2 as a voltage controlled oscillator producing two output signals which have a repetition rate determined by the magnitude of the input voltage. Variable resistor VR2 and gain control VR1 both affect the repetition frequency and in some cases one or other may not be required or may be replaced by a switch permitting the setting of the gain in discrete steps.

The first of the output signals of IC2 is supplied by way of capacitor C5 and gate G2 to the LED so that the latter should blink at a rate representative of line movement speed. Resistor R8 and capacitor C7 connected to the other input of the G2 maintain the LED energised after the output from IC2 goes low.

The second of the output signals from IC2 is supplied via diode D2 as an enabling signal to an oscillator consisting of the three gates G1, G3 and G4, capacitor C8, resistance R8 and the tone control variable resistor VR3. The same signal is also supplied via a diode D3 to the second input of G2. Resistor R6 and capacitor C7 act as a latch to maintain a constant enable signal at the input of the gate G4 above a certain repetition frequency.

The output from the tone oscillator is supplied to two separate output transistors TR2 and TR3. The transistor TR2 has an input resistor R10 and supplies current into the extension socket ES, while the transistor TR3 supplies the loudspeaker LS and receives its signal through input resistor Rll and the variable resistor VR4 which is the volume control.

Claims (8)

1. A bite indicator comprising a vibratable member mounted for direct contact with a fishing line and means for generating an electrical signal in response to vibration of the member, friction between the member and the fishing line serving to cause the member to vibrate in response to line movement.

2. A bite indicator as claimed in claim 1, wherein the vibratable member comprises a resiliently mounted stylus which, in use, is bowed by movement of the line.

3. A bite indicator as claimed in claim 2, wherein the stylus forms part of a piezo-electric, magnetic, moving coil or Hall-effect cartridge serving to convert the vibrations of the stylus into an electrical signal.

4. A bite indicator as claimed in any preceding claim, further comprising means for rectifying the output signal derived from the vibratable member and a voltage controlled oscillator connected to receive the DC signal resulting from rectification, the output frequency of the voltage controlled oscillator being dependent upon the speed of line movement.

5. A bite indicator as claimed in any preceding claim, comprising means for providing both a visible and an audible indication of line movement.

6. A bite indicator as claimed in claim 5, wherein means are provided for enabling the tone of the audible indication to be varied by the user.

7. A bite indicator as claimed in claim 5 or 6, wherein a latch circuit is provided to maintain the visible indication for a length of time after sensing of line movement has ceased.

8. A bite indicator constructed, arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.