AU611046B1 - Marine units - Google Patents

Description

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ZAXMAnljSj bdouwIlj!!qBjapxio ZAXMAfl.LsNdNW11lINH0:a3D9V 'Id 0L 1.25 I 6 SIA I 1 1, 1 1 1 '1 1 3 1 I 1 F i rrr rrrrrrc~ ~i COMMONWEALTH OF AUSTRALIA Form Patents Act 1952-199 COMPLETE

SPECIFICATION

(ORIGINAL)

FOR OFFICE US 4 Class Int. Class Application Number Lodged Complete Application No.

Specification Lodged Published Priority: S Related art: 0C 0 0 0 TO BE COMPLETED BY APPLICANT o o Name of Applicant: BAJ LIMITED Address of Appl'cant: Banwell, Weston-Super-Mare, Avon, BS24 8PD, England 0 Actual Inventor: ARTHUR LEIGHTON BRAKE, ANDREW LAWRENCE CHARLES DAVID PAPWORTH POLE and Address for Service: Ca:re of COLLISON CO., 117 King William Street, Adelaide, South Australia, 5000 Complete Specification for the invention entitled: MARINE UNITS The following statement is a full description of this invention, including the best method of performing it known to A: us: THE COMh,!SSIONER OF PATENTS This form musl be accompanfld by either a provisionrl specilication (Form 9 and true copy) or by a complete speciiclaton (Form 10 and Irue copy) 1 SW iii i I mli a Marine Units 3 4 6 7 8 9 0 0 1 4 e s' 12 13 14 c S 15 o r 16 17 18 oo00 19 oo OC 0 0 0 20 000 21 o0 22 0 0 o e04 23 24 oo 25 0 6 o 6 a 4 t 27 28 29 31 32 33 This invention relates to marine units and is particularly concerned with the construction of such units which are arranged to be deployed on and supported from the sea bed, The invention is particularly concerned with units having an elongate payload-containing body which is to be maintained on the sea bed in an approximately vertical position. The units may serve various purposes but in general the invention is concerned with relatively small unics, for example units of less than ten or more preferably less than five metres in height; for example such units may incorporate electronic equipment such as navigation equipment.

Our British patent specification GB-B-2163200 describes and claims a marine unit which has an elongate payload-containing body and a plurality of legs adapted to rest on the sea bed and to maintain the body in an approximately vertical position, each leg being connected at one end to the body by a pivot adjacent the lower end of the body and each leg being pivotable from a closed position adjacent to the body to a deployed position extending away from the body, and an actuator in the body connected to the legs to pivot the legs simultaneously from the closed position to the deployed position.

According to the present invention the actuator has a common axially moving member which is connected to eac'i leg by means of a link which is pivoted to the leg at a point which is radially within the pivotal axis of the leg and arranged so that on full deployment of the leg forces on the leg tending to return the leg lovojll or rorogo 2ft Polea.j._c. Ci -le..s Dav rth...

PrunglnnA 2 should be cOMiPIted l* -i thOlulIgd- DECLARED at t-Vic, (Name of 9th a o8 9 otlpienut) day of tile asgignw of thon sold (Non'o of (0Irpj 0 r' .X EN s" P Smo'logo l l; tumo ,oM~rs~ino5,~ ~-Rk OrlT Pc~f 4d RIA-,T rt 7-3 19 'r 1 I 1 2 3 4 6 7 8 9 a 0 10 11 ooo0 12 S 13 S~14 16 17 18 0o00 So 0 19 00 0 0 0ooo 0 20 0 00 21 00 0o 22 23 24 0o 0 25 0. 26 27 28 29 31 32 33 to the closed position do not act on the said common member in a direction to tend to return the piston in a direction opposite to the deploying direction. Thus the linkage is self-locking.

According to the present invention the legs of the marine unit are operated by a single actuator the actuator is preferably a piston and cylinder, preferably an annular piston and cylinder coaxial with the marine unit and preferably of double acting construction and more preferably of constant displacement construction. With a double acting constant displacement piston and cylinder arrangement no provision has to be made for "piston rod volume" and operation can be by means of a pump transferring hydraulic fluid from one side to the other side of the piston without connection to a reservoir, although a recuperation chamber may be provided. Preferably the pump is an electrical pump.

At the end of the unit remote from the pivotal axes of the legs, there is preferably a cuver retained by the distal ends of the legs and released by the deployment of the legs. Preferably the legs are held against deployment by a ring removable on deployment.

Preferably there are spring means tending to move the legs in the deployed direction when the ring is removed. In addition such springs may provide cushioning to shield the body from impacts on the legs when they are in an initially deployed condition.

Additionally or alternatively there may be dashpot means between the legs and the body for cushioning purposes and the spring and dashpot may be combined in a single plunger and cylinder structure incorporating a coil spring.

I 1 2 3 4 6 7 8 9 10 o o 0 11 000000 12 13 14 01 15 16 17 18 0000 00a 19 00 0 0000 20 o 00 21 0o 0 22 23 24 0 25 00 0 0 o 26 27 28 29 31 32 33 Preferably the unit incorporates a water parachute or drogue which may initially be connected to all the legs but be releasable from all but one of the legs on deployment of the legs. With this arrangement it is possible to provide that the leg to which the drogue is permanently attached pulls the drogue clear of the body on full deployment.

The invention may be carried into practice in various ways but one particular construction will now be described by way of example with reference to the accompanying drawings, in which: Figures 1 to 4 show various stages in the deployment of a marine unit which is air launched, Figure 1 showing the condition shortly after the unit enters the water, Figure 2 showing the unit lying on the sea bed, Figure 3 showing an intermediate stage in the deployment of the legs and Figure 4 showing the unit with the legs fully deployed and the body of the unit upright; Figure 5 is a side elevation to a larger scale of the lower end of the unit in the region in which the legs are pivoted to the body; Figure 6 is a view similar to Figure 5 but to a smaller scale with one of the legs removed; Figure 7 is an end elevation partly in section seen from the left in Figure Figure 8 is longitudinal section of the portion of the unit shown in Figure Figure 9 is a view, similar to part of Figure 8 showing the legs in a fully deployed position; Figure 10 is a longitudinal section of the top end of the unit; Figure 11 is a fragmentary view showing a spring 1 2 3 4 6 7 8 9 oooo 1 o 000000 0 0 12 0.090 13 o090 0 1 14 0 0 a 00 00a 0 o 0 15 0 16 17 18 0000 00oo 19 00 0 o0o00 20 0 00 21 oO 22 0 a0a9I 23 24 0 25 0 S 4 27 28 29 31 32 33 and dashpot unit for one of the legs; Figure 12 shows a releasable connection between the lanyard holding the drogue and one of the legs; and Figure 13 is a cross section through one of the legs.

Turning now to the drawings, Figure 1 shows a marine unit 10 which has been launched from an aircraft and having descended under the control of an air parachute 11 is now sinking in the water below the surface 12 under the control of a water parachute or drogue 20. The unit comprises a body 13 to which are pivoted three legs 14 each leg being pivoted at its lower end by a pivot pin 15 to the lower end of the body 13 and extending the full length of the body and having an arcuate cross section as can be seen in Figure 13, the arc extending through approximately 1200 so that the three legs between them substantially enclose the body 13.

The air parachute 11 is connected to the remainder of the unit by a load separable link 16a,16b and an easily breakable pull cord 17.

When the unit reaches the sea bed it may become partially buried or may lie horizontally on the sea bed as seen in Figure 2. The body 13 contains an actuator to be described below which, on operation, causes the legs to pivot away from the body so that the body moves towards an upright position through the intermediate position shown in Figure 3 to the fully upright position shown in Figure 4 in which the three legs rest on the ground with the body substantially vertical.

Referring now to Figures 5 to 8 which show the lower end of the unit in detail it will be seen that attached to the lower end of a main body section 21 1 2 3 4 6 7 8 9 0 10 0 0 0000 11 oooo 0 0 0' 12 0000 13 0o 0 14 00 0 00 00 15 0 0 16 17 18 o 0 19 o000o 20 0 00 21 22 0 000 23 24 o°o 25 0 000 00 o 26 0 00 27 28 29 31 32 33 which is only indicated in outline in Figure 8 is ani outer cylinder member 22 and an inner cylinder member 30 between which an annular piston member 25 slides thus forming a first cylinder chamber 23 and a second cylinder chamber 24. The annular piston member 25 has an enlarged upper end 26 and a lower closure member 27 so that the piston member 25 and the closure member 27 enclose the cylinder chamber 24. Within the inner cylinder member 30 there is a pump unit 28 operated by an electric motor driven from batteries 31 and located behind the pump unit 28 as viewed in Figure 8. The two-directional pump 28 has one port connected by a line 32 to the cylinder chamber 23 and the other port connected by a line 33 to the cylinder chamber 24.

Also connected to the line 33 is a hydraulic recuperator or accumulator 29 which is pressurised to maximum sea pressure, say 500 psi (3450 kPa).

The outer cylinder member 22 is formed with three pairs of outwardly extending parallel flanges 34a,34b each of which is formed with a transverse outwardly facing groove 35a,35b which receive a pivot pin 36 on which one of the legs 14 is pivoted and which is retained in position by cap screws 37 passing through holes in the pivot pin 36 and entering tapped holes 38 in the bases of the grooves 35a,35b. The flanges 34a,34b of each pair are restrained from moving away from one another under load by a bolt 39 surrounded by a spacer sleeve 41.

The piston member 25 is formed at its lower end with three sets of lugs 42 each set consisting of three lugs 42a,42b,42c through which passes a pin 43 on which are pivoted two short links 44 which, when the legs are in their non-deployed condition, extend generally ii 1

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1 2 3 4 6 7 8 9 C0C, 10 11 12 13 14 0 4 1 0CQ 4C 15 16 17 18 C 19 00 a 0 04 oo0 C 20 21 00 22 23 24 :4 25 0 4 26 27 28 29 31 32 33 axially upwardly of the unit as can be seen in Figure 8. The upper ends of each pair of liiks 44 are pivoted by a pin 45 to the lower end of one of the legs 14 at a point which, when the legs are in their undeployed position, is approximately radially within the pivot 36 of the leg concerned.

When the legs are to be deployed, the motor is actuated in a direction to deliver hydraulic fluid through the pipe 32 into the cylinder chamber 23 and to withdraw hydraulic fluid from the cylinder chamber 24 through the pipe 33. T*:us the piston member 25 is moved to the right from the position shown in Figure 8 to the position shown in Figure 9. Load is transferred from the piston member 25 to the legs 14 through the links 44 which swing from the position shown in Figure 8 in which they extend generally axially of the unit to the position shown in Figure 9 in which they are approximately radial to the axis of unit. Although not shown in the drawings, the hydraulic system includes valves which, when the pump 28 is not in operation, prevent flow between the cylinder chambers 23 and 24 so that movement of the legs 14 is resisted hydraulically and it may therefore be arranged for the legs to be retained in an intermediate position.

However when the legs are in the fully deployed position as seen in Figure 9, loads on the legs tending to move them towards the undeployed position are directed generally along the length to the links 44 and, if anything, tend to move the piston member further to the right as seen in Fig',re 9 although such movement is not possible as the piston is at its extreme position. A mechanical lock is thus provided.

Turning now to Figure 10, the right hand or upper

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1 2 3 4 6 7 8 9 10 0 0 01 0 13 14 0 e 00 15 0 a o 0 16 17 18 0000 19 0 0 0 19 00o 0 0 00 20 2 0 000 21 22 0 0 23 24 0°o 25 0o 000 o o 26 27 28 29 31 32 33 end of the unit is shown. The upper or distal end of each of the legs 14 is formed with an inwardly directed groove 51 which receives an outwardly directed flange 52 on the outer edge of a generally conical shaped cover member 53. The legs 14 are retained in a fully closed or non-deployed position by a snatch ring 54 having an inwardly facing rebate 55 engaging an outwardly facing rebate 56 on the upper ends of the legs 14. The snatch ring 54 is normally retained in position by a circlip 57 located in a groove 58 in the outer surface of a cylindrical flange 59 extending upwardly from the cover 53. The upper flange of the groove 58 is inclined so that the circlip 57 can be expanded and moved upwardly to clear the cover member.

The snatch ring carries lugs 61 to which are attached lanyards 62 by which the snatch ring may be moved axially upwards as will be described below. The air parachute 11 is stored in a frangible annular container 60 on the upper side of the cover 53. The frangible container 60 also contains a load separable link 16a,16b. The sea parachute or drogue 20 is stored beneath the cover 53.

Operation will now be described with reference to Figures 1 and 10. When the unit is air launched, the air parachute 11 will be pulled out by a static line 64 and the unit suspended from the parachute by means of the load separable' link 16a,16b the integrity of the link being maintained by the tension in the line. When the unit falls into the sea it will sink and the load on the link 16a,16b will fall. The link is constructed so that because of such reduction it will separate and the unit will continue to sink while the drag provided by the air parachute 11 will strain the static line 17 1 2 3 4 6 7 8 9 0000 1 0 0 0000 1 00 12 0 0 13 14 00 a 00 a a 15 0 0 o o o 16 17 18 0000oo 19 0 0 0 00 0 0 o0 20 00 21 00 22 00 o a I 23 24 o" 25 S 26 4 0 27 28 29 31 32 33 which is connected to the lanyards 62 so that the snatch ring 54 is pulled axially clear with release of the circlip 57. Once the rebates 55 and 56 separate from one another the legs 14 are free to open and when this occurs the flange 52 will be cleared from the groove 51 and the cover 53 will come clear from the unit. This will cause the drogue 20 to be released and the unit will descend under the control of the drogue in the manner shown in Figure 1.

Figure 11 shows a combined actuator spring and dashpot arrangement, one of which is located between the body and each of the legs 14 with its axis extending radially of the body. The unit comprises an inner cylindrical member 72 and cup member 74 which can slide in a cylinder 73 which is attached to the leg 14.

The outer cylindrical member 73 is formed with an inwardly directed flange 75 and a compression spring 76 operates between this flange and the closed end of the cup member 74. Outwardly of the inwardly directed flange 75 the outer cylindrical member 73 is provided with another cup member 77 in the base of which there is an aperture 78 normally closed by a flap valve 79 controlled by a spring 31. The closed end of the cup member 74 contains a throttle passage 82.

When the leg 14 is in its closed or non-deployed condition as shown in full lines in Figure 11, the spring 81 and 76 are compressed and thus bias the leg outwardly. When the snatch ring is pulled clear and the leg 14 is released from the restraint by the snatch ring, the spring 76 moves the legs outwardly to the position shown in chain dotted lines in Figure 11 and while this occurs the flap valve 79 opens to admit water to the interior of the device. The dimensions i 1 2 3 4 6 7 8 9 0 oo0 12 o 13 00ooo00 0007 14 o 0 00 C 00 00 15 00 0 0 0 16 17 18 000. 19 00 0 0 oo 20 0 20 a o 21 oo 22 0 00 23 24 oo 25 o o ooo000 26 Soo o 00 o 27 28 29 31 32 23 are such that the legs rotate through approximately half a degree under the influence of the spring 76. If the unit should topple onto its side, any impact will be cushioned by the spring 76 and by the dashpot effect produced by closure of the flap valve 79 (which acts as a check valve) water within the device being expelled through the throttle passage 82.

As mentioned in relation to Figur.e 3 the drogue is permanently connected by a first strop 91 to a lug 92 on one of the legs and is releasably connected by two further strops 93 to the other two legs. Figure 12 shows the release mechanism. Each strop 93 terminates in a ring 94 which engages round a pin P5 passing through a clevis 96 in the body of the unit. One end of the pin 95 is connected to the respective leg 14 by a stop 96. This strop is of sufficient length for the leg to be able to move from the fully closed position to the rartially open position shown in chain dotted lines in Figure 11 without pulling out the pin 95 so that when the unit is descending through the water as shown in Figure 1 it is suspended from the drogue 20 by the three lanyards 91,93. However when the legs are fully opened the strop 96 pulls out the pin 95 thus releasing the ring 94 and the lanyard 93 so that the drogue 20 is pulled clear of the body as is indicated by Figure 3.

In order to provide maximum strength with minimum weight and to provide a degree of cushioning, each of the legs is of double skinned construction as shown in Figure 13, the two skins being separated by a high shear, low weight material such as honeycomb or expanded foam.

Claims (9)

1. A marine unit having an elongate payload-containing body and a plurality of legs adapted to rest on the sea bed and to maintain the body in an approximately vertical position, each leg being connected at one end to the body by a pivot adjacent the lower end of the body and each leg being pivotable from a closed position acjacent to the body to a deployed position extending away from the body, and an actuator in the body and connected to the legs to pivot the legs simultaneously from the closed position to the deployed position, the actuator having a common axially moving member which is connected to each leg by means so arranged that, on full deployment of the leg, forces on the leg tending to return the leg to the closed position do not act on the said common member in a direction to tend to return the piston in a direction opposite to the deploying direction.

2. A unit as claimed in claim 1 in which each leg is connected to the common axially moving member by a link which is pivoted to the leg at a point which is radially within the pivoted axis of the leg.

3. A unit as claimed in claim 1 or claim 2 in which, at the end of the unit remote from the pivotal axes of the legs, there is a cover retained by the distal ends of the legs and released by the deployment of the legs.

4. A unit as claimed in claim 3 in which the legs are held against deployment by a ring removable on deployment. L 11 1

5. A unit as claimed in claim 4 "Ich includes spring 2 means t-.nding to move the legs in the deployed 3 direction when the ring is removed. 4

6. A unit as claimed in claim 5 in which the springs 6 are arranged to provide cushioning to shield the body 7 from impacts on the legs when they are in an initially 8 deployed condition. 9

7. A unit as claimed in any of the preceding claims S 11 which includes dashpot means between the legs and the 12 body for cushioning purposes. C. C 13 14

8. A unit as claimed in claim 7 when dependent on 15 claim 5 or claim 6 in which the springs and dashpot are 16 combined in a single plunger and cylinder structure 17 incorporating a coil spring. 18 o 19 9. A unit as claimed in any of the preceding claims K;3~ 20 which incorporates a water parachute or drogue which is O 21 initially connected to all the legs but is releasable 22 from all but one of the legs on deployment of the legs. o 0.0 23 24 10. A unit as claimed in any of the preceding claims o 25 in which the actuator is a piston and cylinder. p o~c 26 27 11. A unit as claimed in claim 10 in which the 28 actuator is an annular piston and cylinder coaxial with 29 the marine unit and of double acting constant displacement construction. 31 32 33 t I, 12 1 12. A marine unit constructed and arranged to operate 2 substantially as described herein with reference to the 3 accompanying drawings. 4 Dated this 27th day of July, 1989 6 7 BAJ LIMITED By their Patent Attorneys 8 COLLISUN CO.

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