External anchoring harpoon for aircraft

Abstract

An external anchoring harpoon for an aircraft in order to anchor the aircraft on an anchor grid of a platform, the external anchoring harpoon comprises a frame connected to the aircraft, a harpoon head, and a deployment device for deploying the harpoon head. The deployment device comprises a cable, a movement device for moving the cable connected to the frame, the cable being connected to the harpoon head and to the movement device. The deployment device also comprises a main telescopic strut and two secondary telescopic struts so as to enable the harpoon head to be centered under the aircraft and so as to enable the harpoon head to be anchored to the anchor grid.

Claims

1. An external anchoring harpoon for an aircraft for co-operating with an anchor grid of a platform in order both to make landing of the aircraft on the platform safe and also to hold the aircraft down on the platform, the external anchoring harpoon being external to the structure of the aircraft and comprising: a frame configured to be connected to the aircraft; a harpoon head configured to become anchored in the anchor grid; and a deployment device for deploying the harpoon head; wherein the deployment device comprises: flexible connection means having a first end and a second end and connected via the first end to the harpoon head; a movement device for moving the flexible connection means and connected firstly to the frame and secondly to the second end of the flexible connection means; a main telescopic strut provided with a third end and a fourth end, and connected via the third end to the harpoon head and via the fourth end to the frame; and at least one secondary telescopic strut provided with a fifth end and a sixth end and connected via the fifth end to the harpoon head and configured to be connected via the sixth end to the aircraft.

2. The external anchoring harpoon according to claim 1, wherein the frame is configured to be connected to the aircraft by one or more rigid end-restraint type connections.

3. The external anchoring harpoon according to claim 1, wherein the frame is configured to be connected to the aircraft by at least two pivot connections.

4. The external anchoring harpoon according to claim 1, wherein the movement device comprises a winder device for winding the flexible connection means.

5. The external anchoring harpoon according to claim 1, wherein the movement device comprises an actuator.

6. The external anchoring harpoon according to claim 1, wherein the deployment device comprises an angle-changer device connected to the frame and serving to guide the flexible connection means while it is moving, the angle-changer device being arranged between the movement device and the harpoon head so as to change the direction of the flexible connection means between the movement device and the harpoon head.

7. The external anchoring harpoon according to claim 6, wherein the angle-changer device comprises a sheave connected to the frame by at least one pivot connection.

8. The external anchoring harpoon according to claim 1, wherein the main telescopic strut has a first tube and a second tube capable of sliding relative to each other along a slideway connection, together with two first resilient means, the first resilient means being opposing resilient means, the first tube being connected to the harpoon head via a rigid end-restraint type connection and the second tube being connected to the frame via a ball-joint connection, each secondary telescopic strut having a third tube and a fourth tube capable of sliding relative to each other, the third tube being connected to the harpoon head via a ball-joint connection and the fourth tube being configured to be connected to the aircraft by a ball-joint connection.

9. The external anchoring harpoon according to claim 8, wherein the main telescopic strut is of elongate shape along an elongation axis, and the deployment device includes a control rod configured to be arranged between the second tube and the aircraft in order to constrain the main telescopic strut together with the aircraft in rotation about the elongation axis.

10. The external anchoring harpoon according to claim 1, wherein the deployment device comprises a single secondary telescopic strut having two second resilient means, the second resilient means being opposing resilient means.

11. The external anchoring harpoon according to claim 1, wherein the deployment device comprises two secondary telescopic struts arranged on either side of the harpoon head and each comprising a single second resilient means such that the second resilient means of the two secondary struts act in opposition.

12. The external anchoring harpoon according to claim 1, wherein the deployment device comprises a tensioning scissors linkage arranged between the harpoon head and the frame, the tensioning scissors linkage being provided with a pantograph and at least one third resilient means for tensioning the flexible connection means and simultaneously exerting a substantially vertical force on the harpoon head.

13. The external anchoring harpoon according to claim 1, wherein the external anchoring harpoon includes a locking device for locking the anchoring of the harpoon head on the anchor grid, the locking device including control means independent of the deployment device.

14. An aircraft, wherein the aircraft includes the external anchoring harpoon according to claim 1.

15. The aircraft according to claim 14, wherein the aircraft has a fuselage and structural elements, and the frame of the external anchoring harpoon and each secondary telescopic strut are connected to respective ones of the structural elements under the fuselage.

16. The aircraft according to claim 14, wherein the movement device for moving the flexible connection means comprises an actuator arranged under the fuselage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail from the context of the following description of embodiments given by way of illustration and with reference to the accompanying figures, in which:

(2) FIG. 1 shows an aircraft having an external anchoring harpoon;

(3) FIGS. 2 to 4 show a first embodiment of an external anchoring harpoon;

(4) FIGS. 5 and 6 show a second embodiment of an external anchoring harpoon; and

(5) FIG. 7 is a detail view of the harpoon head.

(6) Elements present in more than one of the figures are given the same references in each of them.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows an aircraft 100 having a main rotor 105 positioned about a fuselage 101 and an anti-torque tail rotor 106 positioned at the rear end of a tail boom 103. The aircraft 100 also has main landing gear 110, nose landing gear 115, and an external anchoring harpoon 1 arranged under the fuselage 101 of the aircraft 100. The main landing gear 110 comprises two subassemblies, each comprising a leg 112 secured to the aircraft 100 and a wheel 111.

(8) The external anchoring harpoon 1 is for co-operating with an anchor grid 125 of a platform 120 for landing on a ship in order to make landing of the aircraft 100 on the platform 120 safe, and in order to hold the aircraft 100 down on the platform 120.

(9) The external anchoring harpoon 1 may equally well co-operate with an anchor grid 125 of a landing platform 120 situated on an oil rig or indeed on the roof of a building.

(10) A reference frame X, Y, Z is associated with the aircraft 100. A longitudinal direction X extends from the rear of the aircraft 100 towards the front of the aircraft 100, an elevation direction Z extends upwards perpendicularly to the longitudinal direction X, and a transverse direction Y extends from right to left perpendicularly to the longitudinal direction X and the elevation direction Z.

(11) Two embodiments of the external anchoring harpoon 1 are shown in FIGS. 2 to 6.

(12) In both these embodiments, an external anchoring harpoon 1 comprises a frame 2, a harpoon head 3, and a deployment device 4 for deploying the harpoon 3.

(13) The external anchoring harpoon 1 is arranged so as to be completely under the fuselage 101 of the aircraft 100. The external anchoring harpoon 1 can thus be installed on a large number of aircraft 100 without complicated and expensive adaptation.

(14) The frame 2 is rigid and constituted mainly by two longitudinal beams 21 and 22 and by two crossbars 23 and 24 connecting the two beams 21 and 22 together transversely. The frame 2 is connected to the bottom face of the fuselage 101 by means of the two crossbars 23 and 24 and two fittings 11 and 12 secured to the fuselage 101. Each crossbar 23, 24 is connected to a corresponding fitting 11, 12 by a respective one of two pivot connections. These two pivot connections are in alignment along the longitudinal axis X of the aircraft 100. Each fitting 11, 12 is fastened to a structural element of the aircraft 100.

(15) Furthermore, in each embodiment, the deployment device 4 includes a cable 5 constituting flexible connection means, a movement device 6 for moving the cable 5, a sheave 41, a main strut 7 of elongate shape, and at least one secondary strut 8, 9 of elongate shape. The movement device 6 comprises an actuator having a rod 61 and a cylinder 62 arranged substantially horizontally and parallel to the longitudinal direction X, and thus substantially parallel to the bottom face of the fuselage 101. The cylinder 62 is fastened to the frame 2 by a pivot connection. The cable 5 is connected at a first end 51 to the harpoon head 3 and at a second end 52 to the rod 61 of the movement device 6.

(16) The sheave 41 has a groove in which the cable 5 is guided. The sheave 41 arranged between the movement device 6 and the harpoon head 3 is connected to the frame 2 by a pivot connection. The sheave constitutes an angle-changer device serving to change the direction of tension in the cable 5 from a direction that is substantially horizontal to a direction that is substantially vertical.

(17) The first end 51 of the cable 5 is connected to the harpoon head 3 via a clevis 55. The first end 51 is connected via a rigid end-restraint connection to the clevis 55, the clevis 55 being connected by a ball-joint connection to the harpoon head 3. The second end 52 of the cable 5 is connected to the end of the rod 61 of the actuator 6 so as to form a ball-joint connection between the cable 5 and the rod 61 enabling the cable 5 to accommodate the movement of the actuator 6, thereby limiting the mechanical stresses to which the cable 5 is subjected.

(18) In addition, the main strut 7 is connected by a third end 71 to the harpoon head 3 via a rigid end-restraint type connection and via a fourth end 72 to the frame 2 via a ball-joint connection. Each secondary strut 8, 9 is connected via a ball-joint connection respectively to the harpoon head 3 via the fifth end 81, 91 and to the aircraft 100 via the sixth end 82, 92.

(19) The main strut 7 comprises a first tube 73 and a second tube 74 that can slide relative to each other via a sliding connection, together with two shock absorbers 78, 79 and two first resilient means 76, 77. The two first resilient means 76, 77 are compression springs constituting opposing resilient means and enabling the length of the main strut 7 to vary and enabling it to return to an equilibrium length. The first tube 73 is connected to the harpoon head 3 at the third end 71 and the second tube 74 is connected to the frame 2 at the fourth end 72.

(20) Likewise, each secondary strut 8, 9 comprises a third tube 83, 93 and a fourth tube 84, 94 capable of sliding relative to each other via a sliding pivot connection, together with a shock absorber 88, 98 and at least one second resilient means 86, 87, 96. The third tube 83, 93 is connected to the harpoon head 3 at a fifth end 81, 91, and the fourth tube 84, 94 is connected to a strong point of the structure of the aircraft 100 that is capable of transmitting forces at a sixth end 82, 92 via a support 13, as can be seen in FIG. 2.

(21) Whatever the embodiment of the external anchoring harpoon 1, its operation is substantially analogous.

(22) The deployment device 4 enables the harpoon head 3 to be moved essentially vertically relative to the frame 2 and thus relative to the bottom face of the fuselage 101 of the aircraft 100. The main and secondary struts 7 and 8, 9, by virtue of their variable lengths and by virtue of the forces generated by the resilient means 76, 77, 86, 87, 96, serve to control and to limit these movements of the harpoon head 3 in a substantially horizontal plane so as to ensure that the harpoon head 3 is centered under the fuselage 101 of the aircraft 100 and that it is favorably oriented for anchoring on the anchor grid 125. Likewise, the main and secondary struts 7 and 8, 9 also serve, because of the forces generated by their resilient means 76, 77, 86, 87, 96, to apply forces directly vertically downwards on the harpoon head 3, thereby co-operating in anchoring the harpoon head 3 on the anchor grid 125 of the platform 120.

(23) The pivot connections between the frame 2 and the fittings 11, 12 provide hinging between the frame 2 and the aircraft 100, thereby automatically adapting the orientation of the frame 2 depending on the position of the harpoon head 3 and on the traction direction of the cable 5. As a function of movements of the harpoon head 3 in a substantially horizontal plane, the traction direction of the cable 5 may present an angle relative to a vertical direction as taken relative to the bottom face of the fuselage 101 of the aircraft 100. These pivot connections thus enable the plane of the sheave 41 and the traction plane of the cable 5 to be kept in alignment, thereby limiting the mechanical stresses to which the cable 5 is subjected and that are transmitted in particular to the frame 2.

(24) As a result, the external anchoring harpoon 1 serves to distribute the forces to which the harpoon head 3 is subjected both during landing and anchoring on the anchor grid 125, and also while holding the aircraft 100 down on the platform 120. The main strut 7 serves to take up all of the longitudinal forces that are transmitted to the aircraft 100 via the frame 2 and the fittings 11, 12. Each secondary strut 8, 9 serves to take up all of the transverse forces that are transmitted directly to the aircraft 100 via each support 13. Finally, while anchoring the harpoon head 3 in the grid 125, the vertical forces are taken up mainly by the support 13 via the secondary struts 8, 9, whereas the traction force of the cable 5 for holding the aircraft 100 on the platform 120 is taken up mainly by the fitting 12 via the sheave 41 and the frame 2.

(25) FIGS. 2 to 4 show a first embodiment of the external anchoring harpoon 1 for which the deployment device 4 comprises two secondary struts 8 and 9 arranged on either side of the harpoon head 3, each being provided with single second resilient means 86, 96.

(26) FIG. 2 shows in greater detail how the external anchoring harpoon 1 is installed on the bottom face of the fuselage 101. The two secondary struts 8, 9 are connected via their sixth ends 82, 92 by respective supports 13 at strong points of the structure of the aircraft 100. The two secondary struts 8, 9 are situated in a plane that also contains the harpoon head 3 and the axis of the wheels 111, this plane being substantially parallel to the transverse elevation directions Y and Z. Furthermore, since the two secondary struts 8 and 9 are situated on either side of the harpoon head 3, the two second resilient means 86, 96 behave like two opposing resilient means.

(27) The projections of the main strut 7 and of each secondary strut 8, 9 onto a horizontal plane form an angle of about 90 between one another.

(28) FIG. 4 shows the external anchoring harpoon 1 in its stowed position under the fuselage 101 of the aircraft 100. It can thus be seen that the external anchoring harpoon 1 occupies little space vertically by virtue of using the sheave 41 as angle-changer device together with an actuator 6 in a substantially horizontal position as movement device 6. Furthermore, the actuator 6 is placed as close as possible to the fuselage 101 still for the purpose of minimizing the vertical space occupied by the external anchoring harpoon 1. In this stowed position, the main strut 7 is substantially parallel to the longitudinal direction X.

(29) FIGS. 5 and 6 show a second embodiment of the external anchoring harpoon 1, in which the deployment device 4 has only one secondary strut 8 together with a tensioning scissors linkage 30. This secondary strut 8 has two second resilient means 86, 87 constituting opposing resilient means, and it is preferably connected via its sixth end 82 and a support 13 to a strong point of the structure. The secondary strut 8 lies in a plane that is substantially parallel to the transverse and elevation directions Y and Z and that contains the harpoon head 3 and the axis of the wheels 111.

(30) The projections of the main strut 7 and of the secondary strut 8, 9 onto a horizontal plane form between them an angle of about 90.

(31) The tensioning scissors linkage 30 is formed by a pantograph 31 with two traction springs 32, 32 constituting third resilient means. The pantograph 31 has two sets of links 33, 33, 34, 34 and it is made as two symmetrical portions connected together by four hinge pins 35, 36, 37, and 38. Two first links 33, 33 are arranged parallel to each other and connected respectively to the harpoon head 3 via a pivot connection at a first hinge pin 35, and two second links 34, 34 are arranged parallel to each other and connected respectively firstly to a first link 33, 33 by a pivot connection via a second hinge pin 36 and secondly to the frame 2 via a ball joint at a third hinge pin 37.

(32) Each traction spring 32, 32 is arranged between the frame 2 and a fourth hinge pin 38 connecting together the second links 34, 34. Throughout the action zone of the tension scissors linkage 30, the geometry of the pantograph 31 and the way the traction springs 32, 32 are installed serve to obtain a practically constant thrust force that is oriented mainly vertically and downwards. This thrust serves in particular to guarantee the force needed for engaging and locking the harpoon head 3 to the anchor grid 125.

(33) In addition, in the stowed position, as shown in FIG. 6, the position of the tension scissors linkage 30 folded under the fuselage 101 is practically horizontal and favorable to minimizing the space occupied by the external anchoring harpoon 1.

(34) In addition, in both of these embodiments, since the main strut 7 is of elongate shape along an elongation axis Xa, the deployment device 4 includes a control rod 16 arranged between the fitting 11 and the second tube 74 of the main strut 7, as can be seen in FIGS. 3 to 6. This control rod 16 is connected to the fitting 11 and to the second tube 74 via respective ball-joint connections. The control rod 16 serves to constrain together in rotation about the elongation axis Xa the main strut 7 and the fitting 11, and consequently the main strut 7 and the bottom face of the fuselage 110 of the aircraft 100. As a result, the harpoon head 3 has an orientation for which variation is limited firstly by the presence of a slideway connection between the first tube 73 and the second tube 74 of the main strut 7, and secondly by a rigid end-restraint type connection between the first tube 73 and the harpoon head 3.

(35) Furthermore, the harpoon head 3 is shown in detail in FIG. 7. The harpoon head 3 has a clamp 14 and a locking device comprising a locking link 18, a locking finger 19, and control means 15 constituted by an electromagnet. Such locking of the clamp 14 to the anchor grid 125 is thus obtained by the electromagnet 15 acting on the locking link 18 causing the locking finger 19 to move so as to prevent the clamp 14 from opening.

(36) FIG. 7 also shows a torsion spring 45 constituting fourth resilient means and forming a device for keeping the cable 5 in the groove of the sheave 41. Specifically, the torsion spring 45 bears against the harpoon head 3 and the clevis 55, thereby moving the cable 5 away from the harpoon head 3 when the cable 5 is not under tension so as to tension the cable 5 and prevent it from leaving the groove in the sheave 41.

(37) The ball-joint connections throughout the external anchoring harpoon 1 are preferably ball-joint connections that are free to move about all axes of rotation. Nevertheless, such a ball-joint connection could have a preferred axis of rotation about which rotation is free while freedom to move angularly about other axes is limited. By way of example, such ball-joint connections may be constituted by resilient balls made of elastomer. Such a connection can also replace the pivot connection of the sheave 41, and the frame 2 may then be connected to the aircraft 100 by a rigid end-restraint type connection.

(38) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.