NO311816B1 - Detachable locking device for mechanical coupling - Google Patents

Description

This invention relates to a releasable locking device, particularly for use in lifting devices where a simple and reliable mechanism for disconnecting heavy parcels is required, such as when placing modules in underwater installations. Furthermore, the invention includes the use of shape memory metal in such devices.

In underwater lifting operations, in addition to the usual coupling links such as shackles and dropout couplings, couplings of the "collar lock" type are also used. Both the collar lock and the dropout coupling are types of quick couplings that can be locked or released with simple operations.

A collar lock is designed to grip around a cylindrical part where a collar is arranged at the free end part. The collar lock is provided with a bore with a diameter that is adapted to the diameter of the collar so that it can be inserted over the collar. At a suitable distance from the end part of the collar lock, two cylindrical countersinking pits shaped like stairs of different depth are arranged in the bore. The shallowest countersinking pit that is closest to the collar lock's end part constitutes the locking pit. A sleeve where the locking end portion has a cylindrical bead is placed in the bore. The locking end of the sleeve is divided axially into many segments, so that the locking end of the sleeve consists of many "fingers", each of them with a part of the cylindrical bead placed on its free end portion. The geometry of the bead on the inner side of the sleeve fits complementary to the collar, while its geometry on the outer side of the sleeve fits complementary to the countersinking pit closest to the end part of the bore.

Before coupling, the sleeve is moved to a position so that the sleeve's beads have an axial position in the bore that coincides with the deeper countersink pit that is placed within the countersink pit where the beads lock. Because this countersink pit is deeper, fingers can swing into it when passed over the collar. The beads at the inner part of the sleeve (and the fingers) will be positioned behind the collar by the spring force in the fingers. The collar coupling housing is then guided axially in relation to the sleeve, so that the beads at the outer part of the sleeve are positioned in the recess where the beads are locked, and are thereby prevented from moving out of the collar. When the coupling is released, it is relieved, and the collar coupling housing is pushed axially in relation to the sleeve to a position where the beads on the outer part of the sleeve are positioned above the deepest countersink pit, so that they can swing into this when the sleeve is pulled out over the collar.

In an output coupling, a load-bearing hoop is connected at one end by means of a hinge to a housing. In a borehole in the house, a locking bolt has been installed. The housing is provided with an internal threaded part for attachment to the lifting equipment. The locking pin, which can be displaced axially in the bore in the housing, is arranged to be placed, in the locked position, in a locking hole in the dropout bracket. The outlet coupling is opened by displacing the locking pin out of the hole in the hoop, after which the hoop can swing around the hinge and release the load hanging in the hoop.

Both quick coupling types can be mechanically, hydraulically or pneumatically actuated.

When working underwater, the connecting links must be operated by a diver or ROV (Remote Operated Vehicle - remotely controlled mini-submarine). Alternatively, the quick coupling types can be operated from the sea surface by, for example, a hydraulic connection from an aggregate on a ship to an actuator in the coupling.

The use of divers or ROVs is very expensive and complicated when working at sea. The same applies to the use of long control lines from the surface to great ocean depths, which can also result in an uncertain function.

The purpose of the invention is to remedy the negative aspects of existing equipment, as the new technique uses a new coupling of the multi-hook type and power elements where a phase change in a shape memory metal is indirectly used to operate a locking element in the coupling, which enables the use of a simple and functionally reliable remote control device.

A coupling of the multiple hook type according to the invention, for example, has an outer part (the female part) with a bore where one or more annular countersink pits are arranged in the cylindrical surface. The coupling parts are also provided with a fastening device for connection to a load or lifting equipment. The inner part of the coupling (the male part) is designed so that a cylindrical part of it can be inserted into the bore of the outer part. In this cylindrical part, two or more axial slots are arranged where a locking hook is suspended springily in a hinge shaft in each slot, so that it can swing out and in from/towards the center line of the coupling in a limited sector. In the loaded state, the locking hooks will rest against the bottom of the axial slot, while in the unloaded state they will spring back and have a clearance to the bottom of the axial slot. The clearance can be adjusted by, for example, an adjustment screw placed in the locking hook that spans the hinge shaft. A locking body can be guided in a bore, into between the locking hooks when they are in the extended locked position.

When the coupling's two main parts are brought together, the locking body is positioned outside the sector where the locking hooks can pivot, so that the locking hooks can assume a pivoted position. The inner part of the coupling can thereby be inserted into the outer part of the coupling. When the coupling parts are in the correct position in relation to each other, the locking hooks swing outwards and engage the recesses of the outer part. The locking body is then inserted between the locking hooks and prevents these from swinging back towards the center of the coupling when the coupling is loaded. The coupling thereby forms a fixed mechanical connection.

Release of the coupling can take place when it is relieved by the locking body being moved out of the locking hook's swing sector area. The locking hooks can then be swung inwards, out of the outer coupling's countersunk pits and the inner part of the coupling can be pulled out of the outer part.

When using multi-hook couplings, collar locks and also other types of couplings, it is necessary to move one or more locking elements to control the coupling's locking function. According to the invention, the locking element is clamped between two spring types which pull or push the locking element in opposite directions. In this context, a spring can consist of several springs or a spring system. In a preferred solution, the force from a conventional spring will act on the locking element in the direction towards the locked position, while the force from a shape memory metal spring will act in the opposite direction.

The memory effect in the shape memory metal can be explained by the fact that the material appears in two different structural phases. In the cold state, the material has an easily malleable martensite structure with a yield strength of, for example, approx. 70 MPa, and above the transformation limit austenite structure with a yield strength of, for example, approx. 210 MPa. By changing the mixing ratio between e.g. nickel and titanium in the shape memory metal alloy, the transformation temperature between the structure of martensite and austenite can be kept in the range from -100°C to +100°C. Memory metal is also known which, depending on the temperature, can have two positions without mechanical influence, i.e. that the metal assumes one geometry under the influence of heat and another geometry when the metal cools. Shape memory metal is in and of itself well known and widely available, and is therefore not the subject of this patent application.

When the multi-hook coupling main parts and locking hooks are in the locked position, the ordinary spring that acts on the locking body and has greater tension force than the shape memory metal springs in a cold state, will overcome the force from the shape memory metal springs, and push the locking body to the locked position. When the coupling is to be released in the unloaded state, the shape memory metal is heated. The structure is then transformed into the mechanically strong austenite state. The increased force in the shape memory metal springs is sufficient to overcome the force of the ordinary spring. Thereby, the locking body is moved away from the locking position, so that the hooks can swing in towards the center of the coupling, thereby releasing the mechanical connection between the coupling parts.

A further development of the invention consists in arranging a maneuver/battery pack at the coupling which is connected to the shape memory metal springs. This unit can be controlled from the surface of the sea using known radio/sonar technology. Hot liquid and/or chemical energy in the form of reaction heat from two or more materials can also be used as a heat source. 1 the following describes several examples of preferred embodiments which are visualized in the accompanying drawings, where: Fig. 1 is a principle sketch showing the main components that are part of a releasable lifting arrangement according to the invention where main parts such as load, couplings, lifting equipment and maneuver/battery pack are shown; Fig. 2a and 2b show in section an embodiment of the invention in the case of a multi-hook coupling, where part "a" shows the coupling in a joined locked position, while part "b" shows it in a partially joined, unlocked position; Fig. 3a and 3b show in section the details of the locking body in fig. 2 on a larger scale, where in part "a" the same position as in fig. 2a, while in part "b" the same position as in fig. 2b; Fig. 4a and 4b show in cross-section a multi-hook coupling in principle similar to the one in fig. 2a and 2b, but with a simplified locking mechanism in a version with an ejector bolt; Fig. 5a - 5d show in cross-section an embodiment of a collar lock with locking mechanism according to the invention, where part "a" shows it in the closed position; part "b" shows it in an intermediate position, while part "c" shows the lock in the open position, part "d" shows a section Va - Va in fig. 5a; Fig. 6a and 6b show a partial cross-section of a device according to the invention used in an output coupling where part "a" shows the coupling in the closed position, while part "b" shows the coupling in the open position; Fig. 7a and 7b partially show in section details of the locking hook's suspension (see fig. 2), as fig. 7a shows it from the front, while fig. 7b shows it in section from the side.

In fig. 1, the reference number 1 denotes a load to be placed and then disconnected from a lifting device 4. A remote-operated multi-hook coupling in the form of an outer part 2 and an inner part 3 is connected via a wire 6 to a maneuver/battery pack 5 which is controlled by a displayed transmitter. The coupling parts 2 and 3 are shown here in the disconnected state. Boreholes 26 resp. 27, fig. 2a, is designed to connect the connecting parts 2 or 3 for the lifting equipment. A locking body 13 is designed to lock one or more locking hooks 8 in the locked position. During insertion of the coupling's inner part 3 in the outer part 2, the locking body 13 is positioned in a retracted position, and the locking hooks 8 are pivoted around a hinge shaft 11 towards the center of the coupling. See fig. 2b. A conventional pressure spring 14 is tensioned and presses the locking body against the locking hooks 8. Just before the lock's inner part 3 is brought into the locking position in the lock's outer part 2, a stop 10 on the locking hook 8 is arranged so that it comes into contact with a shoulder 12 in the outer part of the coupling 2. Upon further insertion, the locking hooks 8 are caused to swing outwards around the hinge shaft 11, so that the teeth 9 on the locking hooks 8 engage in the outer part 2 countersunk pits 7. The spring 14 can now push the locking body 13 to the locked position behind/between the locking hooks 8, see fig. 2a.

Shape memory metal springs 15, see fig. 3a, is arranged in a corresponding number of tubes 16 with a base/spring attachment 17, where one end part of the shape memory metal spring 15 is connected. The opposite end part of the shape memory metal spring 15 is connected by means of a tension spring hook 18" to a tension rod 18 which is connected to the locking body 13 via a screw 18' and an insulating fastening element 19. The tube 16 is in the opposite end part relatively bottom/spring fixed 17 , connected by a wound conventional spring 20. The opposite end part of the spring 20 is connected to an insulating nut 21 which is threaded onto a screw 22. The head 22' of the screw 22 spans against an electrically conductive plate 23 which is fixed in an insulating attachment 24. A guide sleeve 25 for the spring 14 is placed in the attachment 24 by means of a screw connection 25'. A cover 24' is attached to the coupling part 3 with bolts 24" and washers 24'". The memory metal springs 15 can be calibrated by adjusting the preload to give equal power.

The hinge shaft 11, see fig. 7a and 7b, are arranged to spring downwards when the locking hooks 8 are loaded, so that the locking hook 8 can come into contact with the support surface 3"" in the inner part 3. When the locking hooks 8 are relieved, they will be lifted from the support surface 3"", thereby gaining clearance for easy turning about the hinge shaft 11. The locking hook 8 is provided at the top with an adjustment screw 52 which is designed to adjust the distance between the contact surface 3"" and the locking hook 8 when the locking hook 8 is in the unloaded state. The distance between the contact surface 3"" and the locking hook 8 is increased by screwing the adjustment screw 52 in towards the hinge shaft 11.

When the locking body 13 is to be moved out of the locking position when the coupling is relieved, a tension is applied to the shape memory metal spring 15 via the plate 23, the screw 22 which rests against the bottom/spring attachment 17 and the tie rod 18 which is grounded. The heat that is then developed by the 15 ohm resistance of the shape memory metal spring brings it into the strong austenitic phase, whereby it contracts with three times the force it had in the cold state. Together, the shape memory metal springs 15 overcome the force from the conventional spring 14, and drive the locking body 13 out of the locking position. The locking arms 8 can now swing in towards the center of the coupling and the inner part 3 can be led out of the outer part 2.

If one of the shape memory metal springs 15 is not allowed to move the attachment 19 during the heating and contraction, it will stretch out the conventional spring 20, whereby the bottom/spring attachment 17 is pulled out from the screw 22 so that the electrical contact is broken. See detail Illa in fig. 3a. This device prevents the shape memory metal spring from overheating, with the risk that it may lose its predetermined geometry.

A multiple hook coupling 2, 3, in fig. 4 has a simplified design for changing the position of a locking body 13. The internal coupling part 3 is provided with an internal threaded part 3" for attachment to the lifting equipment 4. The construction of the locking hooks 8 is as described above. A conventional compression spring 14 is clamped between a to the internal coupling part 3 connected sleeve 3", and the locking body 13. It pushes the locking body 13 in the direction of the locked position, while a shape memory metal spring 38 which is clamped between the internal coupling part 3, and one on the locking body 13 flange 13'. It pushes the locking body 13 in the direction of the unlocked position. The locking body 13 is provided with a firmly connected rail 13".

Upon release of the relieved coupling, see Fig. 4a, the shape memory metal spring 38 is heated, for example electrically through wires not shown, so that it occupies the relatively strong austenite structure. The shape memory metal spring 38 then overcomes the force from the spring 14, and displaces the locking body 13 out of the locking hook's 8 swing segment, whereby they can swing around the shaft 11 out of the countersinking pits 7. Upon further displacement of the locking body 13, the rail 13" hits a bottom 2' in the outer locking part 2 and presses against it.The lock's inner part 3 is thereby moved out of the locked position.

A collar lock housing 28, see fig. 5a, is provided with a bore 29 which is adapted to the diameter of a collar 30, so that the bore 29 can be inserted over the collar 30. Two cylindrical countersinking pits 31, 32 are shaped like stairs of different depths. The shallowest countersinking pit 31, which is closest to the end part of the collar clasp

33, is the locking pit. A sleeve 34, where an active end part has a cylindrical bead 35, is placed in the bore 29. The locking end of the sleeve 34 is divided axially into many segments, so that the locking end of the sleeve consists of many "fingers"

36, each of which has a portion of the cylindrical bead 35 which constitutes the free end portion. The geometry of the bead 35 on the inner side of the sleeve fits complementary in an annular groove 30' under the collar 30, while the geometry of the bead 35 on the outer side of the sleeve 34 fits complementary to the countersinking pit 31 closest to the end part 33 of the bore. The fingers 36 act like leaf springs, and cause the beads 35 on the end part of the fingers 36 can be moved springily radially outwards, but will themselves return to their original shape when they are relieved. A rail 34 is firmly connected to the collar lock housing 28 in its upper end part.

Before coupling, the sleeve 34 is brought to a position where its beads 35 have an axial position in the bore 29 which coincides with the deeper countersinking pit 32 fig. 5c. Because this countersinking pit 32 is deeper than the countersinking pit 31, the beads 35 of the fingers 36 can swing into the countersinking pit 32 when they are passed over the collar 30. The beads 35 at the inner part of the sleeve 34 (and the fingers 36) will be positioned behind by the spring force in the fingers 36 the collar 30, fig. 5b. The collar coupling housing 28 is then displaced axially in relation to the sleeve 34, so that the beads 35 at the outer part of the sleeve 34 are positioned in the countersink pit 31 where the beads 35 are locked and thereby prevented from moving out of the collar 30. When the relieved coupling is released, a shape memory metal spring 38 is heated, for for example by electrical energy through wires not shown, whereby the metal structure is transformed into the mechanically relatively strong austenite structure. The force from the shape memory metal spring 38 thereby overcomes the force from a conventional spring

37, and pushes, via the flange 39", a rail 39 first down towards the collar 30, whereby it also displaces the collar coupling housing 28 axially in relation to the sleeve 34, to a position where the beads 35 are positioned above the deepest countersink pit 32,

so that they can swing into this when the sleeve 34 is pulled out over the collar 30. See fig. 5b. The shape memory metal spring 38 then presses the rod 39 against the collar 30 at the same time as it braces against the sleeve 34. The beads 35, which are now free to move into the countersinking pit 32, out of a position in the pit 30', are pushed over the collar 30 to a free position. See fig. 5a. The coupling's construction enables, for example, a guide line (not shown) to be passed through the rail's 39 bore 39'.

The coupling can be provided with a position lock 49, the purpose of which is to further ensure that the coupling is not inadvertently brought out of the predetermined position. The position lock 49 locks the sleeve 34 in an upper or a lower position by engaging in one of the two slots 50 arranged in the sleeve 34. The movement of the position lock 49 is achieved by using the same mechanism as described above to produce the movement of the sleeve 34, namely a conventional compression spring 49' and a shape memory metal spring 49". The shape memory metal spring 49" is supplied with energy via electrical wires not shown.

In an output coupling 40, fig. 6a, one is locked to a housing 42, by means of a hinge 48, suspended dropout bar 41 of a locking rail 43. The housing 42 is provided with an internal threaded portion 42' for attachment to the lifting equipment 4.

The locking pin 43, which can be moved axially in a bore 45 in the housing 42, is arranged, in the locked position, to be placed in a locking hole 44 in the dropout bracket 41. The locking pin 43 is held in the locked position by a conventional compression spring 46, which spans between a gable 51 in the housing 42 and the rail 43. A shape memory metal spring 47 is used which is extended in relation to its programmed geometry.

The shape memory metal spring 47, which is insulatingly clamped between the gable end 51 of the housing 42 and the pin 43, will, when heated, overcome the force from the compression spring 46, thereby pulling the locking pin 43 out of the locking hole 44 in the dropout bracket 41, fig. 6b. The dropout bracket 41 will then rotate around the hinge pin 48, thereby opening the dropout coupling 40.

The invention makes it possible for lifting and positioning work in connection with, for example, underwater work to be simplified, because the release couplings can be operated remotely from the sea surface.

Claims (11)

1. Device with a releasable split coupling/locking device (2, 3) which has load-bearing releasable locking elements, in particular for lifting goods, where the locking device (2, 3) is placed between a lifting device (4) and a load (1), characterized in that the releasable load-bearing element(s) consists of one (or more) pivotably suspended locking hook(s) (8) tooth(s) (9) which are arranged to be placed in a complementary ) countersinking pit(s) (7) in one locking device part (2), and where a locking body (13) in a position behind/between the locking hook(s) (8) is arranged to prevent the locking hook(s)'s (8) teeth (teeth) (9) in swinging out of the countersinking pit(s) (7), as the locking body (13) is arranged to be brought into a position outside the turning sector of the locking hook(s) (8) by changing the position or rotation, thereby canceling the locking effect . 2. Device according to claim 1, characterized in that the locking hook(s) (9) is provided with a stop (10) which is arranged to meet a shoulder (12) in the outer part (2) of the coupling, whereby the locking hook's (8) tooth ( teeth) (9), when the coupling parts (2, 3) are brought together, are brought into engagement in the complementary locking pits (13). 3. Device according to claim 1 and/or 2, characterized in that the locking hook (8) is spring-suspended in a hinge shaft (11) and that the locking hook (8) is provided at the top with an adjustment screw/device (52) which is adapted to to adjust the suspension length of the locking hook (8). 4. Device according to one or more of the preceding claims, characterized in that the locking body (13) is provided with a rail (13") which is designed to push the inner coupling (3) out of the outer coupling (2) after release has taken place . 5. Device with a releasable split coupling/locking device (2, 3), in particular for lifting goods, where the locking device (2, 3) is placed between a lifting device (4) and a load (1), and where the locking device (2, 3) is locked and opened directly or indirectly by a positional and/or rotational change of a locking body (13), characterized in that the locking body 13's positional or rotational change between the locked and open position is directly or indirectly caused by one or more metals which has the ability to change structure. 6. Device according to claim 5, characterized in that the metal or metals are made up of springy elements. 7. Device according to claims 5 and 6, characterized in that the springy elements are calibrable with regard to force. 8. Device according to one or more of claims 5 to 7, characterized in that the metal or metals which, by structural change, cause the locking body (13) a change in position and/or rotation are connected to, for example, an electric voltage source (5) for heating of the material. 9. Device according to one or more of claims 5 to 8, characterized in that the voltage source (5) is designed to be controlled remotely. 10. Device according to one or more of the preceding claims, characterized in that a position lock (49) is arranged in a housing (28) and locks the sleeve (34) or other locking body in one of several positions. 11. Use of shape memory metal to directly or indirectly shift and/or rotate the position of a locking body (13) between locked and unlocked position in a releasable coupling (2, 3) for lifting operations.