GB2214158A - Load coupling/uncoupling mechanism - Google Patents

Abstract

A load coupling/uncoupling mechanism especially suitable for mounting on a naval vessel to retrieve or relaunch an aircraft capable of hovering flight has a funnel 9 mounted on a gantry, and attached to a cylinder 11 in which a piston 13 with a head centering recess 20 is slidable. A damper 17 is attached to the piston. Pivoted capture/release jaws 14 are connected via springs 16 to the piston 13. Entry of the spherical head on the end of a probe 10 mounted on the aircarft into the cylinder 11 and further upward movement thereof pushes the jaws 14 aside until engagement of the probe head into the recess 20 allows the jaws 14 to pivot back and engage the head from below. To release the head, it is first pushed further upwardly so as to move the piston 13 so far upwardly as to prevent the jaws 14 from springing back into the path of the head when it moves downwardly. (figs. 4 and 5). <IMAGE>

Description

froad CkrlD rDq/bnmml Th.n This invention concerns a load coupling/uncoupling mechanism.

Although the invention is not so restricted, it will hereafter be described with reference to its application to a retrieving and/or launching system for aircraft described and claimed in our Patent GB B,2,104,014.

The invention in GE-B-2,104,014 may be summarised by stating that it describes a system for retrieval and/or launching an aircraft capable of hovering flight (for example an aircraft having a thrust vectoring capability or a helicopter) includes gantry means for mounting on a surface station (for example a naval vessel), and an aircraft capable of hovering in a stationary position with respect to the gantry. The gantry and the aircraft are provided with complementary engagement means which are releasably engageable to allow the whole of the weight of the aircraft to be carried by the gantry. The engagement means on the aircraft are provided in the region of its centre of gravity.In a retrieval sequence, the aircraft hovers with its engagement means within a notional window with respect to the engagement means of the gantry and the engagement means are then engaged.

The present invention seeks to provide a load coupling/uncoupling mechanism which, for its application to a vectorable thrust aircraft such as our Sea Harrier, requires minimal modification to the aircraft, is capable of reliably and securely holding the weight of a fully laden (fuel, payload, arms) aircraft, is relatively simple and light, is semi-automatic in operation, activatable by the flight crew through aircraft rEcverents, and has low maintenance requirements.

According to the invention there is provided a load coupling/uncoupling mechanism, comprising complementary interengageable male and female members one of which is on the load and the other of which forms part of the said mechanism, the male member having an enlarged head secured to a neck and the female member having an entry opening for receiving said head and at least part of said neck, said mechanism further including yieldable obturating means for blocking said entry opening fully or partially by restricting its dimensions to less than the dimensions of said head, biasing means for biasing said obturating means towards the entry-blocking position displaceable engaging means for engaging the male member connected to said biasing means and effective to limit penetration of the head past the said obturating means, and control means for controlling the displacement of said engaging means between a first, load-holding position in which the obturating means engage and hold the male member and a second, load-releasing position in which the biasing means are disabled and the obturating means are disengaged from the male member to cause or allow it to be retracted out of said entry opening.

Preferably, the obturating means consist of a plurality of angularly erg spaced jaw members articulated for movement about a direction orthogonal to the direction of entry and retraction of said head.

The jaw members are preferably accommodated in a housing serving as a cylinder in which is disposed a fluid-pressure operated piston means, the biasing means being connected between said jaw members and said piston means.

The piston means may have a centering recess for engaging the said head, and it may be connected to a damper to provide cushioning of head movements.

The control means advantageously includes sensing means for sensing travel of the head into said entry opening past the obturating means and the engagement of said head between said centering recess and the obturating means.

A piston displacement blocking means actuatable in two stages may be connected to said control means; in the first stage, further movement of said head is permitted to a limited extent insufficient to disengage the obturating means from said head, whilst in the second stage the head is substantially totally immobilised.

Said damper is preferably adjustable to permit displacement of the piston means only when a predetermined threshold of pressure over time has been exceeded, to prevent inadvertent load release.

The invention is described, by way of example only, with reference to the accompanying diagrammatic drawings, wherein Figure 1 is a pictorial perspective view of a ship with a retrieving and launching system for a vectorable thrust aircraft; Figure 2 is a perspective, partially broken-away view of the load coupling/uncoupling mechanism according to the invention, and Figures 3 to 8 are schematic part-sectional and part-elevational views (not all to the same scale) of the mechanism in its various phases of operation.

Referring first to Figure 1, an aircraft retrieving and/or launching system is shown generally at 2. The system includes gantry means in the form of a pillar 3, supported at 4 and 4' by a naval vessel 1, and pivotally carrying an arm 5 articulated at 5' for nodding movement. The arm 5 carries at or near its free end, downwardly directed engagement means in the form of an acquisition ram 8. The acquisition ram 8 is positively movable upwards and downwards with reference to the arm 5 and has at its lower end a receiver 9 of inverted funnel shape. An upwardly directed engagement means in the form of a probe 10 of suitable profile, preferably a ball, protrudes upwards from an aircraft to be retrieved. The aircraft includes nozzles 6 vectorable to provide both lift and propulsion thrust.The receiver 9 houses locking means, to be described below, in the form of a releasable collet fitting which lock on to the probe 10 and anchor it to the receiver 9. In such an anchored condition the retrieved aircraft is carried by the gantry means which must accordingly be designed to bear the full dead weight of such an aircraft. Aircraft location pads 7 are provided around the ram 8.

The ram 8 is pivotally mounted at the end of arm 5 about two orthogonal horizontal axes X and Y and rams are provided to effect movement in these senses; these degrees of freedom, together with provision of upward and downward movement of arm 8 define a notional window within which a probe 10 may be acquired and locked. The aircraft and the gantry are preferably provided with an associated control system, not further described, to control movement of the acquisition ram 8 to ensure that when an aircraft is formatting with its probe 10 within the window1 the acquisition ram homes in on the probe 10 irrespective of movement of the aircraft within the window.

The downwards movement of the acquisition ram 8 is such as to cause the receiver 9 to receive and lock on to the probe 10 of an aircraft hovering below; the force effecting such movement is therefore positive, but not such as to damage or to greatly displace the hovering aircraft. The force of the upward movement must be such as to bodily carry the aircraft upwards into stabilising engagement with the location pads 7, although a large proportion of the mass of the aircraft may still be supported by the lift-generating means of the aircraft.

Thus far, the description follows that in our said GB-B2,104,014. Figure 2 shows a preferred embodiment of the load (aircraft) engaging and releasing mechanism.

Briefly, the coupling mechanism includes an outer casing 11 serving also as a cylinder (as will be explained below) providing a means of capture, hold and release of the connecting probe 10 provided at the centre of gravity of an aircraft, eq. Sea Harrier, as shown in Figure 1. The probe 10 has a cylindrical neck and a spherical head.

In the captured condition, the probe 10 is fully held about its spherical head from both above and below. From above, the head is held by a conical centering recess 20 set centrally in a piston 13, while from below it is supported by three jaws 14, pivotally mounted towards each other, equispaced in the outer casing 11.

The piston 13 has a two-stage locking mechanism 15, which initially restricts piston travel during capture and finally locks solid both the piston 13 and the jaws 14 after capture.

The piston 13 is connected to each of three jaws 14 by way of spring housings 16 which ensure that the jaws 14 close beneath the probe head on capture and also lift the jaws 14 into an open position when the piston 13 is raised via the probe 10 for release.

A damper 17 forming part of the acquisition ram is mounted between the piston 13 and the top of the outer casing 11, providing a time delay on upward lift of the probe 10 for release and a cushioning effect for any vertical probe oscillations.

The funnel 9 is attached to the outer casing 11 for guidance of the mechanism over the probe 10 during capture.

Describing the mechanism in greater detail now, the gantry assembly is provided or associated with a (preferably laser-operated) guidance system, not shown. Lock-on is initiated as soon as the guidance system senses the aircraft-mounted probe 10 within an imaginary spatial 'window' of e.g. 3m x 3m x 3m. Usually, the lock-on mechanism will be extended to engage the probe 10 at an angle. The probe 10 is therefore preferably deflectably mounted, e.g. by a balljoint mounting, for engagement by the funnel 9 attached to the entrance of the locking mechanism.

As the lock-on mechanism continues to accomnaodate the probe 10, the spherical head will penetrate into an entry opening 22 formed in the bottom wall of the cylindrical casing 11. Within the casing 11 and adjacent to the entry opening 22, three angularly equispaced jaws 14 are mounted for pivotal movement about a horizontal pivot axis 24 disposed near one end of each jaw 14. The other end of each jaw 14 has a part-spherical head-engaging surface 26 adjacent to which a spring 28 mounted in the spring housing 16 connects the jaw 14 with the piston 13. Thus on further inward probe travel, the jaws 14 are pushed open against the bias of springs 28, see Figures 3 and 4.

As the jaws 14 move relatively past the probe 10, travel continues until the probe 10 is seated within the above-mentioned conical centering recess 20 set in the piston 13 to face the probe head. At this stage all three jaws 14 spring closed, i.e. pivot back, fully encapsulating the lower half of the spherical head of the probe, see Figure 5.

Once engaged, the head, which is space-stabilised, ensures that the locking mechanism follows every movement of the aircraft.

Referring now to Figure 6, if the aircraft, i.e. the probe, continues to rise within the cylinder 11, an initial stage of the locking system 15 is applied to the piston 13 through slots 29 in the side of the cylinder 11, allowing the probe 10 only a small amount of vertical movement damped by the damper 17. This small amount of movement is indicated in Figure 6 by the gap 30 between opposed arrows and by the broken lines of the positions of the jaw 14 and the spring 28; a schematic arrow 32 indicates locking movement.

Referring to Figures 2 and 6, it will be seen that the top surface of the piston is sector-shaped for reasons explained below.

In Figs. 2 and 6 a part of the piston 13 has been broken away, to show that it is formed with three equispaced slots 34 cooperating with a lock member 36 having a reduced section nose 37. The maximum upward movement of the piston in the Figure 6 position is given by the engagement of the top of the piston with the underside of the nose 37.

After lock-on is achieved, sensors (not shown) indicate this via a control system to the pilot and the gantry operator, e.g. by a series of indicator lights. Following this, the gantry operator manually applies a second stage lock, Figure 7, which locks the piston 13 solid against all three jaws 14, preventing any risk of their opening as a result ef excessive probe movement. Thus, comparing Figure 7 with Figure 6, further inward movement (shown with arrow 32') of the lock member 36 causes the full thickness of the latter to engage with the top of the piston 13. At the same instant, the pilot reduces power whilst still controlling the aircraft in three axes as it is pulled up into the docking pads 7. The aircraft at this stage is fully captured.

The release sequence will now be describeS Prior to release the locking mechanism is kept in its fully locked (Figure 7) state allowing the pilot safely to open up the engine sufficiently to give effective reaction control power.

After engine tests, the lock-on jack 8 is extended, positioning the aircraft to the centre of the imaginary capture window. When ready, the pilot indicates to the operator to remove both primary and secondary stage locks and increases power until hovering is achieved.

For release, the pilot applies sufficient lift for the aircraft mounted probe 10 to push against the seat 20 in the piston 13 upwar' y inside the locking mechanism. This has the effect of opening all three jaws 14 via its spring housing connection 16 to the piston 13, Figure 8, because the jaws 14 have been moved too far upwardly to be able to spring back beneath the path of downward travel of the head.

In order to eliminate any unexpected upward loads releasing the mechanism from the probe before the pilot is ready to go (i.e. pilotinduced oscillation in steadying the aircraft), the damper 17 restricts the rate at which the jaws 14 may open. Therefore, for the pilot to release his aircraft from the mechanism an upward thrust of a predetermined magnitude and/or for a predetermined period, e.g. five seconds must be maintained After the period has elapsed, the jaws 14 will be in the fully open state and the sensors cause the ram 8 to be rapidly retracted. The aircraft at this stage is free to move away from the ship 1 and complete its transition from hovering, i.e. being jet-borne, to forward, i.e. wing-borne, flight.

The sector-shaped configuration of the piston 13 has a number of advantages. Firstly, it provides support for the three pivoting trunnion bars 40 (one is shown in Fig. 2) through which pairs of guide pins 42 of the spring assemblies or housings 16 may slidably pass. Next, the configuration permits the guide pins 42 to extend beyond the piston top when the jaws 14 are displaced by the initial entry of the probe head 14, see Fig. 4. Thirdly, the area of contact and thus undesirable friction between the casing 12 and the piston 13 is reduced. Fourthly, the slots 34 are in effect drainage slots for condensation within the casing, thus preventing or reducing the risk of icing-up in cold weather and consequent seizing-up of the piston 13. lastly, appreciable material, weight and thus costs are saved.

Many modifications are possible within the scope of the invention. Thus the shape of the probe head need not be spherical, with corresponding changes to the shape of surface 26. The shapes of the piston, lock member and jaws may vary and there may be more than three jaws. An iris type of shutter mechanism may replace the jaws.

Nevertheless, having three jaw members 14 with contiguous partspherical supporting faces, as in the illustrated and preferred embodiment, has the advantage that any tendency of the male probe member 10 to 'walk' out of its captured position is resisted.

Furthermore, and at least equally importantly, should one spring assembly 16 fail, the male member 10 will nevertheless be continued to be supported over two-thirds of its lower surface, so disengagement will still be reliably prevented.

Claims (10)

cz 1. A load coupling/uncoupling mechanism, comprising complementary interengageable male an female members one of which is on the load and the other of which forms part of the said mechanism, the male member having an enlarged head secured to a neck and the female member having an entry opening for receiving said head and at least part of said neck, said mechanism further including yieldable obturating means for blocking said entry opening fully or partially by restricting its dimensions to less than the dimensions of said head, biasing means for biasing said obturating means towards the entry-blocking position, displaceable engaging means for engaging the male member connected to said biasing means and effective to limit penetration of the head past the said obturating means, and control means for controlling the displacement of said engaging means between a first, load-holding position in which the obturating means engage and hold the male member and a second, load-releasing position in which the biasing means are disabled and the obturating means are disengaged from the male member to cause or allow it to be retracted out of said entry opening. Amendments to the claims have been filed as follows

1. A load coupling/uncoupling mechanism, comprising complementary interengageable male and female members one of which is on the load and the other of which forms part of the said mechanism, the male member having an enlarged head secured to a neck and the female member having an entry opening for receiving said head and at least part of said neck, said mechanism further including yieldable obturating means for blocking said entry opening fully or partially by restricting its dimensions to less than the dimensions of said head, said obturating means being accommodated in a cylinder in which is disposed a fluid-pressure operated piston means having a centering recess for engaging the said head and being connected to a damper effective to provide cushioning of head movements biasing means for biasing said obturating means towards the entry-blocking position, displaceable engaging means for engaging the male member connected to said biasing means and effective to limit penetration of the head past the said obturating means, and control means for controlling the displacement of said engaging means between a first, load-holding position in which the obturating means engage and hold the male member and a second, load-releasing position in which the biasing means are disabled and the obturating means are disengaged from the male member to cause or allow it to be retracted out of said entry opening.

2. A mechanism according to claim 1, wherein said damper is adjustable to permit displacement of the piston means only when a predetermined threshold of pressure over time has been exceeded, to prevent inadvertent load release.

3. A mechanism according to claim 1 or 2, wherein the obturating means consist of a plurality of angularly equi-spaced jaw members articulated for movement about a direction orthogonal to the direction of entry and retraction of said head.

4. A mechanism according to any preceding claim, wherein the jaw members are accommodated in said cylinder, the biasing means being connected between said jaw members and said piston means.

5. A mechanism according to any preceding claim, wherein the control means includes sensing means for sensing travel of the head into said entry opening past the obturating means and the engagement of said head between said centering recess and the obturating means.

6. A mechanism according to any preceding claim, wherein a piston displacement blocking means actuatable in two stages is connected to said control means; in the first stage, further movement of said head is permitted to a limited extent insufficient to disengage the obturating means from said head, whilst in the second stage the head is substantially totally immobilised.

7. A mechanism according to any preceding claim, wherein the piston means has a sector-shaped configuration effective to support pivotable trunnion bars through which pairs of guide pins of said biasing means may slidably pass in use.

8. A mechanism according to claim 7, wherein said blocking means includes a slidable lock member for sliding across the top of said piston means, said lock member having a shaped reduced-section nose for progressively limiting the freedom of relative movement between the said cylinder and the said piston means.

9. A mechanism according to claim 1, substantially as herein described with reference to and as shown in the accompanying drawings.

10. A retrieving/launching system for aircraft, e.g. mounted on a water-borne vessel, including a mechanism as claimed in any preceding claim.