GB2340016A - A vibration detector for a fishing line - Google Patents

Description

2340016 A vibration detector The present invention relates to a vibration

detector especially but not exclusively a fish bite detector having a vibration transducer which serves to detect vibration in 5 a fishing line when the detector is in use.

Figures 1 and 2 show respective circuit diagrams of previously proposed fish-bite detectors. Thus, Figure 1 shows a piezo-electric transducer 10 coupled, when the detector is in use, to a fishing line so that vibrations on a fishing line result in the generation of electrical voltage oscillations across the transducer 10. This voltage oscillation is applied to an amplifier 12 having a gain adjustment 14 to enable the sensitivity of the detector to be varied selectively. A diode 16 and resistor 18 are connected in series with the output from the amplifier 12, and a capacitor 20 with a resistor 21 in parallel therewith is connected to the resistor 18 so that the output VO,t across the capacitor 20 is used to drive a voltage controlled oscillator or similar, so that a series of pulses are produced, the frequency of which will be proportional to the amplitude and frequency of the vibrations.

The previously proposed circuitry shown in Figure 2 differs insofar as the amplifier 12 is replaced by a comparator 22 having a first input 24 connected to a reference potential vrtf and a second input 26 connected to the centre connection of a potentiometer 28 which is connected so that the potential generated by the transducer 10 is present across its end connections. With the adjustment of the potentiometer 28, a voltage output V.., is obtainable only when the percentage of the output from the transducer 10 as determined by the setting of the potentiometer 28 exceeds the potential V,.f applied to input 24 of the comparator 22. In this way, the sensitivity of the circuit shown in Figure 2 can be adjusted by way of the potentiometer 28.

A problem encountered with the circuits shown in Figures 1 and 2 is that they are both essentially analogue in nature and it becomes difficult to employ readily available digital electronic devices with such circuitry.

The present invention seeks to obviate this problem.

Accordingly, the present invention is directed to a vibration detector having a vibration transducer which serves to detect vibration when the detector is in use, especially but not exclusively for detecting vibration in a fishing line, the detector comprising a pulse generator connected to the transducer to produce a series of electrical pulses in dependence on the output of the vibration transducer and a counter connected to receive such a series of electrical pulses from the pulse generator and to produce an indicator signal in the event that it receives a given number of pulses within a given period of time.

Preferably, the vibration transducer is a piezoelectric transducer.

Advantageously, the vibration detector further comprises adjustment means coupled with the counter to vary the said given number and/or the said given period, to enable the sensitivity of the detector to be adjusted selectively at a reasonable cost without the need for 5 digital potentiometers or digital to analogue converters.

Alternatively, the said counter may be provided with adjustment means which enable the rate of pulses required to produce an indicator signal to be varied.

Preferably, the pulse generator comprises an electronic comparator.

In one construction of the present invention, means are provided to reset the count in the counter to zero at the end of regular periods, and the counter produces an indicator signal in the event that it receives the said given number of pulses within such a period.

An example of a fish-bite detector made in accordance with the present invention is illustrated in Figures 3 to 6 of the accompanying drawings in which:

Figure 3 shows a side elevational view of an assembly comprising fishing rod supported on a bank stick with a detector in accordance with the present invention; Figure 4 shows electronic circuitry of the detector shown in Figure 3; and Figures 5 and 6 show respective explanatory graphs.

The fishing rod assembly shown in Figure 3 comprises a bank stick 30 at the top of which is provided an internally screw-threaded portion 32 by means of which an electronic detector 34, which also acts as a rod rest head, is secured with an attachment part 35 of a bite indicator clamped therebetween. A pivot member 36 is attached by means of a dovetail joint, to the attachment part 35. A fishing rod 38 is supported by the electronic detector 34. The rod 38 is provided with line rings 40 secured to the rod 38 at positions spaced apart therealong, with the fishing rod line 42 threaded through those rings 40 which thereby act as guides therefor.

A stainless steel wire arm 44 extends forwardly from the pivot member 36, and is pivotally attached thereto at one end of the arm, there being a head 46 of the bite indicator which is secured to the other end of the arm 44, and which has a projection resting on the line 42 of the fishing rod 38, at a position between two rings 40 (only one of which is shown in Figure 1), to create a " V" shape in the line. As a result, any increased tension in the line 42 will lift the head 46 in an upward direction, whereas any slackening of the tension in the line 42 will result in a fall of the head 46. Any bite made by a fish on the line of the fishing rod will thereby be indicated, irrespective of whether it results in an increase or decrease in the tension in the line, but some degree of tension in the line will be maintained.

The electronic detector 34 is provided with a wheel which has a grooved periphery 52 engaged by the line 42.

The wheel 50 has spindles 54 supported in trunions 56 which in turn are coupled to the piezo-electric transducer 58.

The electronic detector 34 is further provided with the electronic circuitry shown in Figure 4. This shows how the piezo-electric transducer 58 is used to provide an alarm signal. Thus, the voltage output from the piezoelectric transducer 58 is applied to a first input 60 of a comparator 62 to the second input 64 of which is applied a reference potential V,.f. The output from the comparator 62 is fed to the input of a micro-controller 66 which in turn has two adjustment switches 72 and 74. A first output of the micro-controller 66 is connected to a speaker 74 and the second output from the micro- controller 66 is connected to a light emitting diode 78.

The micro-controller 66 comprises a counter 67, and a light emitting diode drive 68 and a speaker drive 69 connected to respective outputs of the counter 67. The counter and drives may be implemented in software in the micro-controller. Alternatively, the counter could comprise a CMOS counter integrated circuit.

The switch 72 is so connected to the counter 67 that successive depressions of the switch 72 will successively decrement the count required to trigger an output from the micro-controller 66 that will produce a signal at the speaker 76 and the light emitting diode 78. In contrast, successive depressions of the switch 74 will increment this count. A selectively adjustable sensitivity control as regards the size of the vibration that will trigger an alarm is thereby obtained.

Figures 5 and 6 show voltages appearing in the circuitry shown in Figure 4 upon the occurrence of a small transverse vibration in the fishing line 42 and in a large vibration in the fishing line 42, respectively.

In both Figures 5 and 6, V, represents the voltage across the piezoelectric transducer 58, and V2 represents the voltage output from the comparator 62, in each case as a function of time.

It will thus be seen f rom Figure 5 that in the case of a small vibration, in which the output from the transducer 58 oscillates initially with a relatively high amplitude at a relatively low frequency, which oscillation dies away quite quickly, the voltage Vr.f has been exceeded at only three positions, plotting the voltage V, as a function of time and these are shown as three pulses, being the output voltage V2 from the comparator 62.

In the event of a large vibration as shown in Figure 6, the initial amplitude of the oscillations is greater and more frequent, and these oscillations take longer to die down, so that there are a larger total number of pulses generated at comparator 62 and with greater frequency. Either one of both of these characteristics therefore can be used to vary the sensitivity.

Various equivalents to the parts of the circuit shown in Figure 4 that can be substituted for the illustrated parts may occur to the reader without taking the resulting construction outside the scope of the present invention.

Although the piezo-electric transducer 58 is shown coupled to a wheel 50, the latter could be replaced by a nonrotary stylus or any other fishingline contact member.

claims:

1. A vibration detector having a vibration transducer which serves to detect vibration when the detector is in use, especially but not exclusively for detecting vibration in a fishing line, the detector comprising a pulse generator connected to the transducer to produce a series of electrical pulses in dependence upon the output of the vibration transducer and a counter connected to receive such a series of electrical pulses from the puise generator and to produce an indicator signal in the event that it receives a given number of pulses within a given period of time.

2. A vibration detector according to claim 1, in which the vibration transducer is a piezo-electric transducer.

3. A vibration detector according to claim 1 or claim 2, in which the vibration detector further comprises adjustment means coupled with the counter to vary the said given number and/or the said given period.

4. A vibration detector according to claim 1 or claim 2, 20 in which the said counter is provided with adjustment means which enable the rate of pulses required to produce an indicator signal to be varied.

5. A vibration detector according to any preceding claim, in which the pulse generator comprises an electronic comparator.

6. A vibration detector according to any preceding claim, in which means are provided to reset the count in the counter to zero at the end of regular periods, and the counter produces an indicator signal in the event that it receives the said given number of pulses within such a period. 7. A vibration detector substantially as described herein with reference to and as illustrated by (i) the part labelled 34 in Figure 3, and (ii) Figures 4 to 6 of the accompanying drawings.