WO2004050473A1

WO2004050473A1 - Dive propulsion system

Info

Publication number: WO2004050473A1
Application number: PCT/NZ2003/000268
Authority: WO
Inventors: Karl Jason Kwidor; Alan Murray Reynolds; Peter Frodsham Watkinson
Original assignee: Empac Limited
Priority date: 2002-12-05
Filing date: 2003-12-05
Publication date: 2004-06-17
Also published as: AU2003288816A1

Abstract

A dive propulsion system capable of being secured to the body of a diver or to equipment mounted on the body of a diver has a dive propulsion unit (11), an adapter unit (13) which can be secured about the body of the diver, an attachment means (17) for releasably attaching the dive propulsion unit (11) to the adapter unit (13), and a control glove (20) operatively connected to the dive propulsion unit (11) to allow the diver to control its operation. The attachment means (17) allows the dive propulsion unit (11) to be secured to the adapter unit (13) and removed from the adapter unit (13) with ease, such that safety of the diver can be enhanced.

Description

Dive Propulsion System

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a dive propulsion system, adapted for use particularly, but not exclusively, for providing propulsion for underwater or scuba diving activities.

BACKGROUND

Dive propulsions systems have been used for a number of years to provide improved mobility for divers. They can improve diving efficiency both by allowing improved speed through the water, but also by increasing dive times since they can reduce energy expenditure and therefore oxygen requirements.

The most common forms of dive propulsion systems are hand held devices. These are used as tractor units to essentially tow a diver through the water. However these devices have two main disadvantages, one is that they occupy the hands, and the second is that they can be very tiring on the arms. Turning radii are often large, and any turns can require considerable strength. Divers who use such devices often come out of the water with very strained and tired arms.

To overcome these problems, a number of dive propulsion units have been developed that can fit to a person or at least to a piece of dive equipment such as a tank that is attached to a person. These devices often exhibit a range of problems. These problems will be explained as follows;

These units can be difficult to install to or remove from a diver. One such device can be clamped to the back end of a dive tank, but cannot be easily installed or removed by a person in the water. And in an emergency situation, removal and/or installation in a hurry could be vital.

These units can also be difficult to use, and manoeuvrability can be compromised. This is because the units do not fit close to the centreline or to the centre of gravity of the diver. These factors mean that additional energy or strain is required to maintain a heading, and steering can be more difficult.

These units are often situated in a location that is not readily accessible by the hands, making control of the units difficult. Turning the unit on or speed control, or stopping the unit in a hurry can be difficult.

And also, these units can project unduly from the lines of a diver and become hazardous to the diver as the units can snag ropes or seaweed, etc.

OBJECT

It is therefore an object of the present invention to provide a dive propulsion system which will at least go some way toward overcoming the foregoing disadvantages in a simple yet effective manner, or which will, at least, provide the public with a useful choice.

STATEMENTS OF THE INVENTION

Accordingly in one aspect the present invention may broadly be said to consist in a dive propulsion system comprising;

a dive propulsion unit, and

an adapter unit capable of being attached directly or indirectly to the body of a diver, and

each unit being provided with complementary engaging members to enable the dive propulsion unit to be locked to the adapter unit, the system being provided with a release mechanism adapted to disengage the engaging members to release the dive propulsion unit from the adapter unit.

In most cases the adapter unit would be designed to attach to a buoyancy compensator device which is in turn strapped to the back of the diver. However in some cases the dive propulsion unit may be secured directly to the back of the diver. Preferably the adapter unit is designed to be securely attached to a back mounted buoyancy compensator device so that the dive propulsion unit will sit close to the divers body.

Preferably the dive propulsion system includes a remote control device which is accessible to the hands of a diver to whom the dive propulsion system is fitted, the remote control device being operatively connected to the dive propulsion unit.

Preferable the remote control device can be mounted on the hands or arms of a diver to whom the dive propulsion system is fitted.

Preferably the remote control device can be mounted within a full or cutaway glove.

Preferably a glove mounted remote control device can be positioned on the side or back of the fore finger allowing control using the thumb.

Preferably the engaging members and the release mechanism is in the form of a quick release mechanism which is accessible within the normal reach of a user/diver to whom the dive propulsion unit is fitted.

Preferably the engaging members and the release mechanism are positioned such that they are contained within the lines of the assembled dive propulsion unit and adapter unit. The advantage of this being that the releasable attachment does not protrude and form a snag hazzard.

Preferably the engaging members and the release mechanism are able to release the dive propulsion unit when the dive propulsion unit is producing thrust.

Preferably the thrust of the dive propulsion unit is able to assist with the release of the dive propulsion unit.

Preferably the quick release mechanism is provided with a biasing device which is adapted to move the dive propulsion unit away from the adapter unit when the dive propulsion unit is released. The biasing device could be any device capable of exerting a force, for example a spring, a rubber shape, a chamber containing a gas, but preferably is a metal spring. Preferably the engaging members and the release mechanism are provided with a power assist system to facilitate release of a dive propulsion unit. The power assist mechanism can be powered by a number of means, for example, compressed air from a dive tank, a tensioned or compressed spring, an electrical supply or a pyrotechnic device, but preferably is powered using compressed gas from a dedicated cylinder.

Preferably the dive propulsion unit and the adapter unit are also provided with complementary guide members adapted to guide the units into a pre-locking position such that the complementary engaging members substantially overlie each other in the pre-locking position prior to the units being locked together.

Preferably the complementary guide members comprise a tongue and a socket.

Even more preferably the tongue and socket are each tapered in a complementary manner.

Preferably the adapter unit is adapted to be connectable to an item of diving equipment, for example, adapted to be connectable to a buoyancy compensator device.

Preferably the dive propulsion unit includes a streamlined shaped housing.

Preferably the dive propulsion unit includes a chamber adapted to be used for buoyancy compensation of the dive propulsion unit, and preferably the chamber is so sized as to be capable of providing the dive propulsion unit with a positive buoyancy when immersed in fresh or sea water.

Preferably the streamlined shaped housing includes fairings adapted to fair the dive propulsion unit with a diver or an item of diving equipment.

Preferably the adapter units are adapted to mount more than one dive propulsion unit.

Preferably the dive propulsion units are able to be mounted adjacent to the abdomen of a diver.

Preferably the dive propulsion unit contains an electric motor and a battery pack.

In a second aspect the present invention may broadly be said to consist in a dive propulsion unit which is adapted to include a buoyancy compensation chamber. Preferably the buoyancy compensation chamber is provided with a streamlined housing which forms part of the dive propulsion unit.

In a third aspect the present invention may broadly be said to consist in a dive garment provided with an integrated adapter unit substantially as described herein. Such a garment is particularly suited to aiding a person in carrying out a sea rescue, and when used with a dive propulsion unit as described herein can be used to help a rescuer tow a person to safety, allowing the rescuers hands to be used to support the person being rescued.

Preferably the dive garment also includes the features of a buoyancy compensator device.

In a fourth aspect the present invention may broadly be said to consist in a control device for a dive propulsion system, the control device comprising at least part of a glove, and at least one control interface device associated with the glove.

Preferably the control interface device is in the form of a switch.

In a fifth aspect the present invention may broadly be said to consist in a quick release attachment means suitable for assembling a first and a second article, the attachment means comprising an elongate member on the first article which is able to be mated with a complimentary socket on the second article, and also at least one stud on either the first or the second article which is capable of mating with a latch on the opposing article, such that engagement of the elongate member into the complimentary socket causes the stud to generally align with the latch.

The invention may also broadly be said to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of the said parts, elements or features, and where elements or features are mentioned herein and which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

The invention consists of the forgoing and also envisages constructions of which the following gives examples. BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be more particularly described by way of example only with reference to the accompanying sheets of drawings in which;

Figure 1 is a perspective exploded view of a dive propulsion system showing an adapter plate for installation of the system onto a dive tank,

Figure 2 is a perspective view of the assembled dive propulsion system shown in figure 1 ,

Figure 3 is an exploded view showing a set of attachment points between a dive propulsion unit and an adapter plate of the dive propulsion system,

Figure 4 is a detailed view of a releasable attachment means,

Figures 5 and 5a are perspective views of an adapter plate suited to mount a dive propulsion unit to a dive tank,

Figures 6 and 6a are perspective views of an adapter tube suited to mount a dive propulsion unit to a buoyancy compensator device (BCD) whilst also providing storage for a dive tank,

Figures 7 and 7a are perspective views of an adapter plate suited to mount one or more dive propulsion units directly to a BCD,

Figure 8 is a perspective view of a multi-adapter suited for mounting onto a BCD or similar diving apparatus and capable of providing a number of mounting points for any combination of adapter plates of figures 7 or 7a, or dive tanks,

Figure 9 is an exploded perspective view showing a pair of adapter plates of figure 5 used to mount a pair of dive propulsion units about a single dive tank,

Figure 9a is perspective view showing the components of figure 9 assembled, Figures 10 and 10a are exploded perspective views showmg an adapter tube of figure 6 used to mount a dive propulsion unit to a BCD and providing storage for a dive tank,

Figure 11 is an exploded perspective view showing manual release of a dive propulsion unit from an adapter,

Figure 12 is a an exploded perspective view showing an alternative or emergency release of a dive propulsion unit from an adapter,

Figure 13 is a schematic view of a power assisted emergency release system,

Figure 14 is an exploded perspective view of some of the main components of a dive propulsion unit,

Figures 15 to 15b are perspective views showing how a single adapter tube of figure 6 can be used to mount either one or two dive propulsion units,

Figures 16 to 16b are perspective views showing how an adapter plate of figure 7 can be used to mount a dive propulsion unit directly to a BCD,

Figures 17 to 17b are perspective views showing how an adapter plate of figure 7a can be used to mount a pair of dive propulsion units directly to a BCD,

Figures 18 and 19 are exploded perspective views showing the use of a multipoint adapter of figure 8 to mount a number of dive tank and dive propulsion unit combinations,

Figure 20 is an exploded perspective view showing a dive vest adapted to include a mounting fixture for a dive propulsion unit,

Figure 21 is a perspective view of the dive vest of figure 20 including a buoyancy compensation chamber, Figures 22 to 23 are perspective views showing an optional manual steering feature,

Figure 24 is an exploded view showing an alternative releasable attachment means,

Figure 25 is a plan view showing two dive propulsion units fitted about an adapter tube using the releasable attachment means represented in figure 24,

Figures 26 to 26b are side and plan views of the releasable attachment means used in figure 24,

Figure 27 is an exploded view showing an alternative dive propulsion unit housing arrangement,

Figure 28 is a series of views showing an alternate steering system, and

Figure 29 is a further series of views showing yet a further steering system.

DETAILED DESCRIPTION

With reference to Figures 1 and 2, a dive propulsion system (10) is shown comprising a dive propulsion unit (11) and an elongate adapter unit (13). The adapter unit (13) has a concave lower surface (13 a) along its entire length enabling the adapter unit (13) to be mated with a dive tank. The dive propulsion unit (11) and an adapter unit (13) are shown adjacent to a dive tank (14) and a buoyancy compensator device (BCD) (16) in an exploded view in figure 1, and fully assembled in figure 2. A body strap (15) can also be included to provide improved stability between the dive propulsion unit (11) and a wearer/user. The body strap (15) can be particularly important in relation to directional control whilst moving through the water under the influence of the dive propulsion unit. In this example the body strap (15) is shown attached to the adapter unit (13), but clearly the body strap (15) could be attached directly to the dive propulsion unit (11). Attachment means (17) are provided to secure the dive propulsion unit (11) to the adapter unit (13), the details of which will be explained with reference to the figures which are described below.

The dive propulsion unit (11) can also be provided with a streamlined housing (18), and preferably the streamlined housing (18) includes fairings which are adapted to fair the dive propulsion unit (11) with a diver or an item of diving equipment to which the dive propulsion unit (11) is fitted. Such a streamlined housing (18) not only improves the streamlining of the dive propulsion unit (11), but also reduces the chances of entanglement with seaweed or ropes. Also, having the user and the dive propulsion system (10) adequately faired together can reduce overall drag and increase speed and or range when using the dive propulsion system (10).

The streamlined housing (18) can also provide an air chamber (not shown) which can be used to give the dive propulsion unit (11) positive buoyancy. Positive buoyancy is clearly an advantage when installing or removing the dive propulsion unit (11) in or around the water, where it would be much simpler to retrieve the unit (11) if it floated when it became disconnected from a user. The air chamber can be adjustable in volume and used as a buoyancy compensation feature

A remote control device (19) is also provided to enable control of the dive propulsion system (10). The remote control device is capable of communicating with a control system within the dive propulsion unit (11) to control the operation of a motor and optionally a steering system. Additional details of the dive propulsion unit and the motor and steering systems are described with reference to figures 14, 22, 23, 28 and 29 below.

While the remote control device (19) is shown fitted within a glove (20) it could be mounted in a number of locations, for example, on the arm, on the end of a tether, on the body of the diver, or on an appropriate location on the dive propulsion unit (11). The glove has been chosen as a preferred location for a number of reasons, (a) it eliminates the need for yet another appendage about the neck of a diver, (b) it places the controller literally at the finger tips of the diver, or in this case accessible to the thumb, and (c) it further enhances the "hands-free" objective of the dive propulsion system (10) by allowing control to be achieved even while the hands are partially occupied. In the example illustrated the remote control device (19) incorporates a number of push buttons (19a) and a display screen (19b). These push buttons (19a) are located to be easily activated using the thumb of the same hand to which the glove (20) is fitted. The push buttons (19a) can be used to provide manual control inputs to the dive propulsion unit (11), for example for steering purposes, or to control the operation of the motor or, for example one switch can stop or start the motor, another can accelerate the motor and another can decelerate the motor.

In some cases if two dive propulsion units (11) are fitted to a diver, one can be controlled by a glove on one hand and the other controlled by a glove on the other hand. The advantage of this being that control is intuitive, the left hand controlling the left dive propulsion unit (11) and the right hand controlling the right dive propulsion unit (11). The display screen (19b) can be used to convey such information as battery life remaining.

While the example illustrated uses push buttons (19a) these can be replaced with a number of proximity sensors and a target element which is located on the thumb and which can be used in conjunction with the proximity sensors to input control information from the diver. The advantage of this arrangement being that there is a reduced possibility of inadvertently pushing a button (19a) when using the hands for any reason.

The remote control device (19) communicates with the dive propulsion system (10) via a cable (21) which is capable of transmitting electrical or digital signals. This cable (21) can for example contain a number of electrical wires for transmitting signals, can contain a pull cord for activation of a release mechanism which will be explained further below, and can be protected by an outer sheath. Alternatively the remote control device (19) communicates with the dive propulsion system (10) using sound or radio waves or infra-red signals.

Preferably the control system of the dive propulsion unit (11) is also provided with a pressure sensor, and the controller is able to calculate ascent rates, and the controller is further able to cut power to the motor of the dive propulsion unit (11) if an unsafe ascent rate is detected.

Straps (22) which form part of the BCD (16), and which may be designed to secure the dive tank (14) can be used to secure the adapter unit (13) to the BCD (16). Slots (22a) are provided in the adapter unit (13) for the straps (22) to pass through. Such a dive propulsion system (10) provides a number of advantages, some of which will be more apparent with reference to the following figures, but some of which are already apparent. These advantages can be detailed as follows; (a) the system can be secured to an item of diving equipment in such a way as to be close to the centre of gravity of the diver and not too far from the centreline of the diver, (b) the system is streamlined in shape and the housing of the dive propulsion unit (11) is provided with a fairing to further enhance the streamlining and to reduce the possibility of the unit becoming entangled with seaweed or ropes etc, and (c) the dive propulsion unit (11) is easily installed and removed, even while in the water.

With reference to each of the figures, unless otherwise stated, the dive bottle (14) and the BCD (16) shown in these figures do not form part of this invention.

With reference to Figure 3 the attachment means (17) are shown in more detail. The adapter unit (13) is provided with two studs (23) and a socket (25) on its upper surface. The dive propulsion unit (11) is provided with a latching mechanism (27) and a tongue (29). The latching mechanism (27) will be described in more detail with reference to figure 4 below.

To attach the dive propulsion unit (11) to the adapter unit (13) is a simple process of sliding the tongue (29) into the socket (25). The socket (25) is provided with a tapered lead-in portion (31) to assist with the initial aligning of the dive propulsion unit (11) with the adapter unit (13). The tongue (29) is complimentary in shape to the tapered lead-in portion (31), such that the action of inserting the tongue (29) into the socket (25) acts to orientate the dive propulsion unit (11) such that latching mechanism (27) contained on the dive propulsion unit (11) is appropriately aligned with the two studs (23), allowing the latching mechanism (27) to be mated with the studs (23). The studs (23) are bullet shaped to assist with the final guiding and entry of the studs (23) into the latching mechanism (27). Further details of the studs (23) and the latching mechanism (27) are described with reference to figure 4 below.

In this way the dive propulsion unit (11) is provided with a three point attachment to the adapter unit (13), which can be made with relative ease even when in the water. The three point attachment system, coupled with the waist belt (15) of the adapter unit (13) has the advantage of providing good stability for the dive propulsion unit (11), particularly longitudinal stability. Such stability, relative to the longitudinal axis of the divers body is important, both when trying to maintain a heading and when carrying out ftirning manoeuvres.

Turning manoeuvres can be carried out with relative ease using the dive propulsion system (10) of the present invention. Much tighter turning radii can be achieved than those achieved using traditional hand held propulsion units, and with less strain on the limbs of the user/diver. To effect a turn the user/diver can simply roll his back away from the centre of the turn using an asymmetric deflection of his flippers, and then deflect both flippers towards the centre of the turn, the flippers acting in a similar way to the elevators on an aircraft.

With reference to Figure 4 the details of the latching mechanism (27) and the studs (23) are described in further detail. The latching mechanism (27) is secured to the dive propulsion unit (11) using fasteners which pass through the lugs (38).

The latching mechanism (27) comprises two parallel latch members (39) spaced apart in a side by side relationship, each held within guide members (41), and biased towards a latched position by latch springs (43). The ends (40) of the latch members (39) are tapered in a similar manner to the sharp end of a wood chisel, the sloping face of the taper facing outwards from the dive propulsion unit (11). The ends (40) of the latch members (39) extend into holes (44) in the guide members (41).

The studs (23) have a bullet shaped nose (33) to aid with entry into the holes (44) in the latching mechanism (27), and a recess (35) which is used to engage with a latch in the latching mechanism (27). The studs (33) are also provided with a stud spring (37) which is held in place by a washer (36). The washer (36) has a small tab on its inner diameter which is aligned with a slot (36a) on the stud (23). In this manner the washer (36) is able to travel along a portion of the length of the stud (23), but is restrained from coming off the end of the stud because the slot (36a) does not extend that far. The base (23a) of each stud (23) is secured into the adapter unit (13) by any suitable means, for example using a cement or are cast in situ, etc.

In use, the latching mechanism (27) is guided onto the studs (23) such that each stud (23) enters each respective hole (44), the studs initially contacting the sloping face of each respective tapered end (40) of the latching members (39), the studs then pushing the latch members (39) against the force of the latch springs (43) and moving further into the hole (44) until the respective recess (35) on each stud (23) aligns with each tapered end (40) of the latching members (39)and of the latching members (39) then move under the action of their respective latch springs (43) to engage with the recesses (35). Once the studs (23) have engaged with the holes (44), the tongue (29) is not able to move out of the socket (25) - refer to figure 3 above.

As the studs (23) enter the holes (44) the washer (36) contact the guides (41) adjacent to the holes (44) and cause the stud springs (37) to be compressed. This compression of the stud spring is later used to aid in causing the studs (23) to move away from the latching mechanism (27) when the latch members (39) are withdrawn during a release event. This stud spring (37) action is particularly useful in a situation where rapid removal of the dive propulsion unit (11) from the adapter unit (13) is required in an emergency.

The handle (45) can be used to withdraw the latch members (39) and thereby release the studs (23).

Clearly any resilient material for example rubber or a gas filled chamber could be used in place of each of the springs (37) and (43).

While a three point attachment means (17) as described herein has certain advantages, an attachment means using any number of attachment points could be used, the criteria simply being; ease of attachment, stability of the attachment, and ease of release of the attachment. An alternative two point attachment means is described with reference to figures 24 to 26 below.

The three point attachment means (17) as described herein has the added advantage that upon operation of the release handle (45) the dive propulsion unit (11) is caused to move away from the adapter unit (13) by the action of the stud springs (37). And, the removal of the tongue (29) from the socket (25) is in the same direction as the thrust from the dive propulsion unit (11). The combination of these two factors means that the dive propulsion unit (11) can be removed from the adapter unit (13) without undue difficulty even if the dive propulsion unit (11) is still producing thrust. This can be an important feature as removal of the dive propulsion unit (11) while it is producing thrust may be required in an emergency situation for example in a situation where control to the dive propulsion unit has been lost or it is otherwise not possible to shut-off the motor of the dive propulsion unit (11). The three point attachment means (17) has another advantage in that the thrust load produced by the dive propulsion unit (11) is transferred into the adapter unit (13) in the form of a shear load in the studs (23), and there are no significant loads transferred into the latch members (39). Clearly the studs (23) can easily withstand such a shear load, and since the latch members (39) are not significantly loaded by the thrust load, the latching means (17) will not tend to bind under load.

With reference to Figures 5 and 5a the adapter units (13), which have already been detailed with reference to figure 3 above are shown, primarily for comparison with a range of alternative adapter units, which are described with reference to figures 6 to 7a below.

With reference to Figures 6 and 6a a variation on the adapter unit (13) is presented. In this case the adapter unit is in the form of an adapter tube (47). This adapter tube (47) can be fitted to a (BCD) in the same manner that a dive tank is fitted, and can be used as a mounting adapter for one or more dive propulsion units (11), whilst also providing storage for a dive tank. The neck straps (49) can be used to retain a dive tank within the adapter tube (47). These neck straps (49) are shown disconnected in figure 6, and connected in figure 6a as they would be when a dive tank is installed. The connection can for example be achieved using complementary hook and loop fastening means attached adjacent to the end of each mating strap (49).

In the example illustrated, three pairs of studs (23) and three sockets (25) are provided (two of each are visible, the others being out of sight on the opposing side of the tube about the circumference of the adapter tube (47). This adapter tube (47) can be used to mount a single dive propulsion unit (11) to the uppermost pair of studs (23) and socket (25) for example, or two dive propulsion units (11) could be mounted, one on each side of the adapter tube (47) for example. Clearly, depending on the relative size between the adapter tube (47) and the dive propulsion units (11), any number of dive propulsion units (11) could be mounted about the adapter tube (47). The adapter tube (47) can also be provided with a body strap (15).

With reference to Figures 7 and 7a a further variation on the adapter unit (13) is presented. In this case the adapter unit is in the form of an adapter plate (51) having a convex shaped bottom surface (53). Each adapter plate (51) is provided with at least one pair of studs (23) and at least one socket (25) to enable dive propulsion units (11) to be mounted onto the adapter plate (51). The adapter plate (51) can also be provided with a body strap (15).

The adapter plate (51) shown in figure 7 is provided with one pair of studs (23) and a socket (25), while the adapter plate (51) shown in figure 7a is provided with two pairs of studs (23) and two sockets (25), showing that the adapter plate (51) could be adapted to support any number of dive propulsion units (11).

Such an adapter plate (51) can be used to mount one or more dive propulsion units (11) directly to a BCD which is designed for use with a dive tank, the adapter plate (51) being fitted to the BCD in place of the dive tank. The straps or other attachment means designed to secure a dive tank to the BCD can be used to secure the adapter plate (51) to the BCD. This equipment can be used for example when snorkelling or otherwise operating close to the surface of the water, but where a dive propulsion unit (11) is desired. An example of such a situation could be a surf rescue operation, a military exercise, or simply exploring a reef.

With reference to figures 5 through 7a it is clear that the adapter unit (13) can take many forms and be adapted to fit to a range of diving equipment. Further variations for example can be an adapter unit adapted to fit to a re-breather unit, or an adapter unit adapted to fit directly to a users body, for example adapted to fit to the users back, front, legs or arms.

With reference to Figure 8 a multi-adapter (55) is shown and is suited for, mounting onto a BCD or similar diving apparatus and capable of providing a number of mounting points for any combination of adapter plates of figures 6 to 7a, or dive tanks. Typically the multi-adapter (55) can be secured to onto a BCD or similar diving apparatus using straps, and any equipment or adapters can also be secured to the multi-adapter (55) using straps. Alternatively the multi- adapter can include a latching mechanism (27) and a tongue (29) such that it can be secured using studs (23) and a socket (25). A number of slots (57) are provided in the multi-adapter (55) for this purpose.

The multi-adapter is illustrated in figure 8 having three recesses (56) , but clearly it could have any number of recesses (56). Details of the use of the multi-adapter (55) are described with reference to figures 18 and 19 below. With reference to Figures 9 and 9a a variation on the use of the adapter units (13) from that shown in figures 1 and 2 is described. These two figures show the use of a pair of adapter units (13) being fitted about a single dive tank to allow a pair of dive propulsion units (11) to be installed. This arrangement is shown in an exploded view in figure 9 and fully assembled in figure 9a.

With reference to Figures 10 and 10a the use of the adapter tube (47) is described. In this example a single dive propulsion unit (11) is shown fitted to the adapter tube (47). The adapter tube (47) is secured to a BCD (16) for example using the straps (22) of the BCD which are normally used to secure a dive tank (14). The dive tank (14) can be secured within the adapter tube (47) using the neck straps (49). This configuration is shown in an exploded view in figure 10 and with the adapter tube (13) assembled to the BCD (16) in figure 10a.

With reference to Figure 11 details of the manual release of the attachment means (17) is described. Details of the attachment means (17) are described with reference to figure 4 above. In this figure the use of the handle (45) is shown. When the handle is pulled, the latching mechanism releases the studs (23), the stud springs (37) (not shown) push the dive propulsion unit (11) away from the adapter tube (47) and then the tongue (29) can be withdrawn from the socket (25).

Due to the positioning of the handle (45) and the simplicity of operation, this manual release function can be carried out by the diver to whom the dive propulsion system (10) is fitted, or by a dive buddy, in a very short period of time. This can be particularly advantageous in an emergency situation. It should also be noted that if the dive propulsion unit (11) is being removed while powered, the propulsion of the unit will in fact assist with removal of the dive propulsion unit (11) from the adapter tube (47). And clearly, while this function has been described with reference to an adapter tube (47), the same is true for any style of adapter described herein.

With reference to Figure 12 an alternative or emergency release of the attachment means (17) is described. In this example a rip cord (59) is attached to the handle (45) which can be pulled from some location remote from the handle (45). This is advantageous since in some configurations the handle (45) may not be readily accessible to the diver. While the rip cord (59) could be any length and positioned anywhere about the body of the diver, it is considered advantageous to connect it to the control cable (21). This eliminates the need for yet another appendage to hang about an equipped diver. It also has the advantage of being immediately accessible. Preferably the control cable (21) is adjustable in length, and can be adjusted to suit any diver. The length of the cable can be such that if the arm to which the glove (20) is fitted is extended to it's full length, then the rip cord (59) will be caused to pull on the handle (45) (not shown), to cause the dive propulsion unit (11) to be released from the adapter tube (47). Alternatively the control cable (21) can be pulled by a free hand, or by a dive buddy, so that the rip cord (59) will pull on the handle (45).

In any case, the control cable (21) can be provided with an in-line connector (61) such that the in-line connector (61) will disengage at the same time that the rip cord (59) is pulled. This feature can be advantageous in causing the dive propulsion unit (11) to power down during an emergency release.

With reference to Figure 13 a power assisted release system (63) is described. This power assisted release system (63) can be used in place of the manual latching mechanism (27) described herein, and includes a compressed gas cylinder (65), a spring loaded firing pin (67) and a release pin (69). When the release pin (69) is pulled, the spring loaded firing pin (67) pierces the cap of the compressed gas cylinder (65) releasing compressed gas which is directed via a conduit (71) to act on pistons (73) which cause the latch members (39) to withdraw. In this way, the compressed gas is used to achieve the same action as pulling on the handle (45), as with the manual latching mechanism (27).

The expelled compressed gas (75) from the conduit (71) can be used to inflate a retrieval balloon (not shown) which can be attached to the dive propulsion unit (11). Activation of the power assisted release system (63) can also be used to trigger an emergency locator beacon or similar device.

With reference to Figure 14 a number of the main components of the dive propulsion unit (11) are described. These include a battery housing (77) and a motor housing (79) which are connectable using latches (81). An output shaft from a motor (not shown) can protrude from the outlet bore (83) and drive a propeller (not shown). The propeller operates within a duct (85), the duct (85) being supported on two support arms (87), which are represented in the figure in an exploded arrangement and rotated 90 degrees from their normal orientation. The duct (85) can be pivotally mounted on the support arms (87) and the variable alignment of the duct (85) can be used for trimming purposes or for steering. The orientation of the duct can be controlled by use of an adjustable strut (89) and strut clamp (91).

Preferably the motor housing (79), battery housing (77) and the duct (85) are in-line to form a torpedo shape and have a minimal diameter which can be mounted close to the body of a diver. This has the advantage of aligning the centreline of thrust of the dive propulsion system (11) as closely as possible with the centre of drag of the combined diver and dive propulsion system (10).

In practice the dive propulsion system can be fitted to a diver and a trial carried out to determine trim requirements. If the diver experiences a tendency to move in a nose down or a nose up direction when under power, the adjustable strut (89) can be adjusted or frhnmed accordingly to alter the direction of the thrust from the dive propulsion unit (11) to counter this tendency.

While this example uses a battery and an electric motor, clearly any self contained motor and energy source could be used to drive the propeller. The inventor has found that an approximately 0.4 Kilowatt, permanent magnet DC geared motor, having a 4:1 reduction gearbox, and a solid state Cr-F-Li battery combination to be effective.

With reference to Figures 15 to 15b a variation on the features described with reference to figures 10 and 10a is described. These figures simply illustrate more completely how a single adapter tube (47) can be used to mount either one or two dive propulsion units (11).

With reference to Figures 16 to 16b the use of an adapter plate (51) to mount a dive propulsion unit (11) directly to a BCD (16) is shown. The adapter plate (51) can be secured to a BCD (16) using the straps (22) which would normally be used to secured a dive tank. A dive propulsion unit (11) can then be attached to the adapter plate (51). Such a configuration can be useful in situations where a dive tank is not required, but where propulsion would be an advantage. With reference to Figures 17 to 17b a configuration similar to that described with reference to figures 16 to 16b is described. The difference being the style of the adapter plate (51) which in this case is a double adapter plate and can be used to mount two dive propulsion units (11).

Also shown is the positioning of a mini dive tank or pony bottle, which can be stowed between the dive propulsion units (11) if required, to provide air for buoyancy control and/or for a supply of breathing air.

With reference to Figures 18 and 19 the use of a multi-adapter (55) is described, showing how the multi-adapter (55) can be used to mount a number of dive tank and dive propulsion unit combinations. It can be seen that the recesses (56) on the multi-adapter (55) can be occupied by either adapter tubes (47), adapter plates (51) or dive tanks (14), to provide a variety of dive tank and dive propulsion unit combinations.

The multi-adapter (55) can be provided with a latching mechanism (27) and a tongue (29) (not shown) as described herein, such that the multi-adapter can be secured onto an adapter having the studs (23) and socket (25) as shown in figure 18, or can be secured using straps (22) as shown in figure 19.

Also introduced in figure 18 is a dive garment (95) incorporating an adapter unit, that is, having a pair of studs (23) and a socket (25) built into the back of the dive garment (95). Such a dive garment (95) can be used to mount a dive propulsion unit directly and is described in further detail with reference to figures 20 and 21 below. As illustrated the dive garment (95) is in the form of ,a vest and includes a tail portion (97) which extends to the hips and secures the garment about the buttocks and crotch for additional stability. In effect the tail portion (97) performs a similar function to the body strap (15) described herein, in providing improved stability between the dive propulsion unit and the body of the diver.

While the dive garment is illustrated as described above, clearly it could take any form, for example a full or partial wetsuit form, or the form of a body harness. The essential features of the dive garment (95) being the inclusion of means to mount a dive propulsion unit (11), in this case by the provision of studs (23) and a socket (25), and means to stabilise the dive propulsion unit (11) relative to the body of a user. With reference to Figure 20 the dive garment (95) is illustrated to highlight it's ability to have a dive propulsion unit (11) mounted directly to it. The dive garment (95) can also be provided with a pouch (99) to support a mini dive tank (93).

With reference to Figure 21 a further variation on the dive garment (95) is shown, and in this case the dive garment (95) also includes a buoyancy compensation chamber (101). The dive garment (95) can also be provided with straps (22) for the purpose of attaching a dive tank if desired. These straps are in addition to the studs (23) and socket (25) and give the dive garment (95) additional flexibility of use, that is it can be used as a buoyancy compensator device or as a garment to use with a dive propulsion unit (11) or for use with any combination of dive propulsion units (11) and dive tanks (14) when used in conjunction with a multi-adapter (55).

With reference to Figures 22 to 23 an alternative use of the pivoting duct (85) is described. If desired, the pivoting duct (85) can be used for steering purposes. This is shown in it's most basic form in these figures, simply having a handle (103) which can be manually controlled. In a more sophisticated version the steering control can be achieved using remote mechanical systems, or by the use of powered servo-actuators, for example servo-actuators using pneumatic, electrical or hydraulic power sources. Clearly a pneumatic servo-actuator could use a dive tank as a source of compressed air. Alternative forms of steering using moving vanes or compound ducts will be described further with reference to figures 28 and 29 below.

With reference to Figure 24 a dive propulsion system having an alternative releasable attachment means is described, the releasable attachment means comprising a pair of pins (105) attached to an adapter tube (107), the pins being adapted to be received by a receptor housing (109) having two bores and a latching mechanism. The bores and latching mechanism will be described with reference to figures 26 to 16b below. In this case the attachment means uses only two attachment points and adequate stability of the dive propulsion unit (11) can be achieved due to the length and rigidity of the pins (105) and the strength of the receptor housing (109).

The other features of the dive propulsion system being similar to the dive propulsion system (10) described herein. With reference to Figure 25 an assembly of two dive propulsion units (11) fitted about an adapter tube (107) using the releasable attachment means described with reference to figure 24 and figures 26 to 26b is shown.

With reference to Figures 26 to 26b the alternative releasable attachment means initially described with reference to figure 24 is described in further detail. Figure 26 shows a side view and figure 26a shows a plan view. Figure 26b shows the latching means in more detail.

The two pins (105) are rigidly secured in a mounting block (106) which forms part of the adapter tube (107) (not shown). These two pins (105) can be inserted into two bores (111) within the receptor housing (109), and can be retained within the bores (111) by the latching members (113) which engage with recesses in the pins (105). To release the dive propulsion unit (11), a handle (115) can be pulled which draws the latching members (113) back releasing the pins (105). Springs (117) can be provided to assist with removal of the pins (105).

It can be seen that this releasable attachment means has many features similar to that described with reference to figures 3 and 4 above. The essential features of both being; ease of attachment, stability of the attachment, and ease of release of the attachment. A power assisted version of the releasable attachment means as described with reference to figures 24 to 26b could be made by simply incorporating the relevant features of the power assisted release system (63) described herein.

With reference to Figure 27 an alternative dive propulsion unit (11) housing arrangement is illustrated. In this example the housing (119) integrates a streamlined housing, a battery housing and a motor housing, and is manufactured in two halves, a nose section (121) and a tail section (123). The two sections (121) and (123) are joined using latches (125), the two sections being appropriately sealed at the join. The housing (119) can store a battery (127), and a motor (not shown) can be housed in the tail section (123).

With reference to Figure 28 an alternative steering arrangement is illustrated. In this example the duct (85) of the dive propulsion unit (11) is provided with a swivelling aft nozzle (131). In this example the duct (85) can be fixed or held in a set orientation for trimming purposes, and the swivelling aft nozzle (131) is caused to move to alter the direction of thrust and thereby produce some level of steering control. The swivelling aft nozzle (131) can be operated manually via a handle or using a servo-actuator as described herein

With reference to Figure 29 a further alternative steering arrangement is illustrated. In this example the duct (85) of the dive propulsion unit (11) is provided with movable vanes (133) which can be used to alter the direction of thrust and thereby produce some level of steering control. A set of movable vanes (133) can be oriented horizontally as illustrated to produce steering control in a vertical plane, and a further set of movable vanes (133) can be oriented vertically to produce steering control in a horizontal plane. These sets of movable vanes (133) can be operated manually via handles or using a servo-actuators as described herein.

VARIATIONS

Throughout specification the invention has been described as a dive propulsion system, however it could be used in a number of swimming applications, and in these cases it may be better described as an aquatic propulsion system.

DEFINITIONS The term "dive tank" used herein is intended to mean any cylinder or tank used to provide a supply of breathing air.

The term "diver" used herein is intended to mean any user of a dive propulsion unit whether the user be diving, snorkelling, carrying out a rescue or swimming.

Throughout this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

Claims

1. A dive propulsion system comprising a dive propulsion unit, and an adapter unit capable of being attached directly or indirectly to the body of a diver, and each unit being provided with complementary engaging members to enable the dive propulsion unit to be locked to the adapter unit, the system being provided with a release mechanism adapted to disengage the engaging members to release the dive propulsion unit from the adapter unit.

2. A dive propulsion system as claimed in claim 1, wherein the adapter unit is designed to be securely attached to a buoyancy compensator device so that the dive propulsion unit will sit close to the divers body.

3. A dive propulsion system as claimed in any preceding claim, wherein the dive propulsion system includes a remote control device which is accessible to the hands of a diver to whom the dive propulsion system is fitted, the remote control device being operatively connected to the dive propulsion unit.

4. A dive propulsion system as claimed in any preceding claim, wherein the engaging members and the release mechanism axe in the form of a quick release mechanism which is accessible within the normal reach of a user/diver to whom the dive propulsion unit is fitted.

5. A dive propulsion system as claimed in claim 4, wherein the quick release mechanism is provided with a biasing device which is adapted to move the dive propulsion unit away from the adapter unit when the dive propulsion unit is released.

6. A dive propulsion system as claimed in any preceding claim, wherein the dive propulsion unit and the adapter unit are also provided with complementary guide members adapted to guide the units into a pre-locking position such that the complementary engaging members substantially overlie each other in the pre-locking position prior to the units being locked together.

7. A dive propulsion system as claimed in any preceding claim, wherein the engaging members and the release mechanism are positioned such that they are contained within the lines of the assembled dive propulsion unit and adapter unit.

8. A dive propulsion system as claimed in any preceding claim, wherein the engaging members and the release mechanism are able to release the dive propulsion unit when the dive propulsion unit is producing thrust.

9. A dive propulsion system as claimed in any preceding claim, wherein the dive propulsion unit includes a chamber adapted to be used for buoyancy.

10. A dive garment provided with an integral adapter unit for use with a dive propulsion system as claimed in any preceding claim.