GB2119980A

GB2119980A - A device for use by a diver to give a signal

Info

Publication number: GB2119980A
Application number: GB08213608A
Authority: GB
Inventors: Madelyn Carrol Freeman
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-05-11
Filing date: 1982-05-11
Publication date: 1983-11-23
Also published as: GB2119980B

Abstract

A hand-held device (10) is provided for use by an aqualung diver to give a selection of audible signals underwater to a fellow diver, and accordingly comprises a housing (11) water-tightly containing a battery (12), a sound transducer (13) and circuitry (14) including a switch (14a). The housing (11) includes a lug (11f) for attaching the device (10) to the person of the diver to guard against loss. A rotary switch knob (14a1) is provided at the opposite end from the transducer (13) for controlling the signals produced. The signals are pulses of tone, for example, 2 kHz tone pulses of 100mS duration at a repetition rate of 2 pps (normal) or 4 pps (emergency). <IMAGE>

Description

SPECIFICATION A device for use by a diver to give a signal This invention relates to a device for use by a diver to give an audible signal underwater.

According to the invention there is provided a self-contained device adapted to be carried by a diver on his person for use by him to give at least one type of audible signal underwater, comprising a housing containing an electric battery, a sound transducer and electrical circuitry including a selectively operable switch for energizing the transducer from the battery to produce the signal, wherein the battery, transducer and circuitry are protected against the effects of the water and the pressure.

Preferably the device is adapted to be held in the hand of the diver, the housing being generally cylindrical with the transducer at one end thereof and a manually operable part of the switch located at or adjacent the other end of the housing. For example, the manually operable part of the switch may be operatively rotatable about an axis extending longitudinally of the housing.

The protection of the battery, transducer and circuitry against the effects of the water is preferably due to water-tight sealing provied by the housing, although encapsulation may be used to augment this.

To guard against the device being accidentally lost by the diver while underwater, means is preferably provided for attaching the device to the person of the diver.

Preferably the battery is both replaceable and rechargeable.

Preferably the switch is selectively operable to cause the production of selectively different signals. Furthermore, preferably these signals are a finite plural number of audible signals which are noticeably different from each other.

Alternatively, for reasons of economy the device may be such that only a single type of signal is producible by operation of the switch In either case, the circuitry may be adjustable to change a characteristic of the signal or of at least one said signal. This can be especially useful where it is required to have a plurality of such devices adjusted so that the or each signal producible by each device is noticeably different from the or each signal producible by each other device, so that signals from different divers can be distinguished from each other.

The invention will be further described by way of example with reference to the accompanying drawings, wherein: Figure 1 is a sectioned side elevation of a device embodying the invention; and Figure 2 is a circuit diagram of the circuitry of the device of Fig. 1, including the battery and the transducer.

Referring to the drawings, the illustrated device 10 is adapted to be carried by a diver on his person for use by him to give anyone of two or three (or more) audible signals which are noticeably different from each other, underwater. The device 10 comprises a housing 11 containing an electric battery 12, a sound transducer 1 3 and electrical circuitry 14 including a selectively operable switch 1 4a for energizing the transducer 1 3 from the battery 1 2 to produce the selected signal. The battery 12, transducer 1 3 and circuitry 14 are protected against the effects of the water and pressure by water-tight sealing provided by the housing 11.

The device 10 is adapted to be held in the hand of the diver, the housing 11 being generally cylindrical with the transducer 1 3 at the lefthand end (11 a in Fig. 1) of the housing 11 and a knob 1 4a1 of the switch 1 4a at the right hand end 11 b of housing 11. The switch knob 1 4a, is fixed to a rotary shaft 1 4a2 for rotation about the axis of the shaft 1 4a2, extending longitudinally of the housing 11, to operate electrical contacts 1 4a3 of the switch 14a.

Describing the housing 11 in more detail, it comprises a tubular main body 11 C of ABS plastics material, a fixed end cap 11 d of PVC (polyvinylchloride) plastics material at the left hand end 11 a, cemented to the main body 1 1 c to form a water-tight seal at that end, a removable end cap 11 e, also of PVC plastics material, screwed into the end of the main body 1 1 c at the right hand end 11 b of housing 11 and a lug 11 f of PVC plastics material cemented to the main body 11 C. The lug 11 f is formed with a hole 11 f1 to receive a stainless steel clip (not shown) for attaching the device 10 to the person of the diver, to guard against accidental loss of the device.

Two O-ring seals 11 g1 and 11 g2 are provided between the main body 1 1 c and the end cap 11 e, whilst a third O-ring seal 11 h is provided between the end cap 11 e and the switch shaft 1 4a2, to make the housing 11 completely water-tight.

The transducer 1 3 is mounted to the end cap 11 d in such a way that it is accoustically coupled to the ambient water at the left hand end 11 a of housing 11 when submerged. The circuitry 14 includes flexible wiring 1 4b interconnecting the battery 12, the switch contacts 1 4a3 and a printed circuit board 14c, so that when it is desired to change and/or recharge the battery 12, the end cap 11 e can be unscrewed from the main body 11 c, with- drawing the switch 1 4a, after which the battery 1 2 can be extracted and disconnected (in a conventional manner). The battery 1 2 is preferably a nickel cadmium rechargeable battery, type PP9.

Referring particularly now to Fig. 2 of the drawings, the circuitry 14 comprises a tone generating circuit 1 4d, a first timing circuit 14e1, a second timing circuit 14e2, a transistor switch 14f and a power amplifier 14g.

The switch 1 4a is a two-gang, four-position switch. In the first position of switch 1 4a, device 10 is switched off. In the second position of switch 1 4a, pulses of tone from tone-generating circuit 14dare passed by transistor switch 14f to power amplifier 14g and thence to the transducer 13, the duration and frequency of the pulses being determined by the first timing circuit 1 4e1 controlling transistor swtich 1 4f. In the third position of switch 1 4a, the situation is the same as in the second position of switch 1 4a, except that the duration and frequency of the pulses are different, being controlled by the second timing circuit 1 4e2 instead of first timing circuit 14e1, controlling transistor switch 14f.In the fourth position of switch 14a, a coding circuit 14h controls transistor switch 14f to produce pulses of tone having a regular pattern of frequency and duration which the diver may use to give a signal of prearranged meaning to a colleague or colleagues in the vicinity.

To this end, contacts 1 4a3 of switch 1 4a have two centre terminals a0 and bo respec- tively connected by moving contacts Ca and cb in the first position of the switch to fixed contacts a1 and b1, in the second position of switch 1 4a to fixed contacts a2 and b2, in the third position of the switch 1 4a to fixed contacts a3 and b3 and in the fourth position of switch 1 4a to fixed contacts a4 and b4.

Fixed contacts a2, a3 and a4 serve to connect power from centre contact a0 to tonegenerating circuit 14din the second, third and fourth positions of switch 14a, and are interconnected with each other and to circuit 14for that purpose. Contacts b2, b3 and b4 are respectively connected to timing circuit 14e, timing circuit 1 4e2 and coding circuit 1 4h to supply power to each of these three circuits respectively from centre contact b0 in the second, third and fourth positions of switch 1 4a. Centre contacts a0 and by are accordingly both connected to the battery 1 2.

The fixed contacts a1 and b1 are not connected to anything, so that the battery 1 2 is effectively open-circuit in the first position of switch 14a.

The device 10 is intended to be especially of use to an aqualung diver in a party of aqualung divers to signal to his colleagues underwater.

It is preferred that the second position of switch 1 4a should produce audible pulses of two kilohertz tone, the pulse duration and frequency being one hundred millisecond duration, two pulses per second ("pps"). In the third position of switch 1 4a, it is preferred to produce one hundred millisecond pulses of two kilohertz tone at a rate of four pulses per second, it being understood by the divers that this higher frequency indicates an alarm requiring immediate emergency action of some kind or other. The pattern of two kilohertz tone pulses produced by coding circuit 14h may be any pattern found suitable for use by divers. The design of each of circuits 1 4d, 1 4e1, 1 4e2 and 1 4h and of transistor switch 14f and power amplifier 149 are generally conventional and contain no out-of-the ordinary features.

The printed circuit board 1 4c may contain adjustment devices (not shown) for adjusting a characteristic of one or more of the signals, for the purpose of distinguishing the device used by one diver from a similar device used by another diver.

Preferably device 10 is capable of withstanding the water pressure down to a depth of fifty metres.

Claims

1. A self-contained device adapted to be carried by a diver on his person for use by him to give at least one type of audible signal underwater, comprising a housing containing an electric battery, a sound transducer and electrical circuitry including a selectively operable switch for energising the transducer from the battery to produce the signal, wherein the battery, transducer and circuitry are protected against the effects of the water and the pressure.

2. A device as claimed in claim 1 wherein the device is adapted to be held in the hand of the diver.

3. A device as claimed in claim 2 wherein the housing is generally cylindrical with the transducer at one end thereof.

4. A device as claimed in claim 3 wherein a manually operable part of the switch is located at or adjacent the other end of the housing.

5. A device as claimed in claim 4 wherein the manually operable part of the switch is operatively rotatable about an axis extending longitudinally of the housing.

6. A device as claimed in any preceding claim wherein the protection of the battery, transducer and circuitry against the effects of the water is due to water-tight sealing provided by the housing.

7. A device as claimed in any preceding claim wherein means is provided for attaching the device to the person of the diver.

8. A device as claimed in any preceding claim wherein the battery is replaceable.

9. A device as claimed in any preceding claim wherein the battery is rechargeable.

10. A device as claimed in any preceding claim wherein the switch is selectively operable to cause the production of selectively different signals.

11. A device as claimed in claim 10 wherein a finite plural number of audible signals which are noticeably different from each other can be selectively produced by operation of the switch.

1 2. A device as claimed in any one of claims 1 to 9 wherein a single type of signal is producible by operation of the switch.

1 3. A device as claimed in claim 11 or 12 wherein the circuitry is adjustable to change a characteristic of the signal or of at least one said signal.

14. A plurality of devices each as claimed in claim 1 3 adjusted so that the or each signal producible by each device is noticeably different from the or each signal producible by each other device.