Buoyancy system for an aircraft

Abstract

A buoyancy system (10) for an aircraft (1), the buoyancy system (10) being provided with at least one inflatable float (15). The buoyancy system (10) has at least one inflator (25) and at least one actuator (30) interposed between the inflator (25) and a float (15), the actuator (30) having a cylinder (35) and a rod (40) partially received in the cylinder (35). The rod (40) is secured to a piston (50) defining a first chamber (61) within the cylinder (35) and in fluid flow communication with the inflator (25), and a second chamber (62) within the rod (40) and in fluid flow communication with the float (15), and the piston (50) has a channel (63) to put the first chamber (61) into fluid flow communication with the second chamber (62), the deployment device (20) having a shutter (70) for shutting the channel (63).

Claims

1. A buoyancy system for an aircraft, the buoyancy system comprising: an inflatable float; and a deployment device comprising an inflator and an actuator interposed between the inflator and the float, the actuator having a cylinder and a rod secured to the float, the rod being inserted in part in the cylinder and being slidable relative to the cylinder, the rod being secured to a piston, the piston co-operating with the cylinder to define a first chamber within the cylinder and co-operating with the rod to define a second chamber within the rod, the first chamber being in fluid flow communication with the inflator, while the second chamber is in fluid flow communication with the float, the piston having a channel for putting the first chamber into fluid flow communication with the second chamber; the deployment device having a shutter for shutting the channel in a retracted position of the actuator so that gas fed to the first chamber causes the actuator to extend by the rod moving in translation and for not shutting the channel in an extended position of the actuator after the movement in translation, in order to enable the gas to inflate the float.

2. The buoyancy system according to claim 1, wherein the shutter includes a finger extending in the cylinder, the finger penetrating into the channel when the actuator is retracted.

3. The buoyancy system according to claim 2, wherein the finger is secured to an end wall of the cylinder.

4. The buoyancy system according to claim 1, wherein the actuator includes an abutment to limit the extent to which the rod can be extended out from the cylinder.

5. The buoyancy system according to claim 1, wherein the deployment device includes a strap fastened to the float in order at least to limit the freedom of movement of the float relative to the actuator.

6. The buoyancy system according to claim 5, wherein the strap extends between the cylinder and an outer envelope of the float.

7. The buoyancy system according to claim 1, wherein the deployment device includes at least one apron sheet fastened to the float in order at least to limit entry of water into a cabin facing the float.

8. The buoyancy system according to claim 1, wherein the float is hollow and has a hollow float center, and the rod includes an elongate portion slidably received in the cylinder and followed by an angled portion passing through the hollow float center.

9. An aircraft provided with a fuselage, wherein the aircraft includes the buoyancy system according to claim 1, the cylinder being fastened to the fuselage.

10. The aircraft of claim 9, wherein the cylinder is secured inside a compartment in the fuselage on a first side of the fuselage.

11. The aircraft of claim 9, further comprising a second inflatable float in fluid connection with a second deployment device, the second inflatable float being disposed on a second side, opposite a first side, of the fuselage.

12. A buoyancy system for an aircraft, the buoyancy system comprising: an inflatable container defined by an outer envelope enabled to hold pressurized gas; and a deployment device having an inflator and an actuator, the actuator being interposed between the inflator and the container, the actuator having a cylinder, a piston, and a rod, the rod having a first end section and a second end section, the first end section of the rod being disposed in the cylinder and slidable relative to the cylinder, the second end section of the rod being secured to the container, and the first end section of the rod being secured to a piston; the piston cooperating with the cylinder and the rod to define a first chamber within the cylinder and a second chamber within the rod, the second chamber being interposed between the piston and the container; the piston further comprising a channel fluidly communicating the first chamber with the second chamber; and the first chamber fluidly communicating with the inflator and the second chamber fluidly communicating with the container such that entry of pressurized gas into the first chamber moves the actuator in translation from a retracted position to an extended position, allowing pressurized gas to inflate the container.

13. The buoyancy system of claim 12, further comprising pipework fluidly communicating the first chamber with the inflator.

14. The buoyancy system of claim 12, further comprising pipework fluidly communicating the second chamber with the container.

15. The buoyancy system of claim 12, where the inflator is configured to remove pressurized gas from the container to retract the container.

16. The buoyancy system of claim 12, further comprising a shutter for selectively shutting and opening the channel within the piston.

17. A buoyancy system for an aircraft, the buoyancy system comprising: an inflatable envelope capable of holding pressurized gas; and a deployment device in fluid communication with the envelope, the deployment device having an inflator and an actuator disposed between the inflator and the envelope, the actuator having a cylinder, a piston, and a rod having a first end section and a second end section, the first end section of the rod slidingly disposed within the cylinder, the second end section of the rod being connected with the envelope, and the first end section of the rod being connected with a piston; the piston cooperating with the cylinder and the rod to define a first chamber within the cylinder and a second chamber within the rod, the second chamber disposed between the piston and the envelope; the piston fluidly communicating the first chamber with the second chamber, with the first chamber fluidly communicating with the inflator and the second chamber fluidly communicating with the envelope.

18. The buoyancy system according to claim 17, wherein the deployment device extends the actuator in order to cause the rod to move in translation relative to the cylinder as a result of the envelope being inflated.

19. The buoyancy system of claim 17, further comprising pipework fluidly communicating the first chamber with the inflator.

20. The buoyancy system of claim 17, further comprising pipework fluidly communicating the second chamber with the envelope.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS 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 is a section of an aircraft of the invention shown with a non-deployed float;

(3) FIGS. 2 and 3 are sections showing an actuator of the invention;

(4) FIG. 4 is a diagram explaining how an actuator of the invention extends;

(5) FIG. 5 is a section of an aircraft of the invention shown with a float while it is being deployed;

(6) FIG. 6 is a section of an aircraft of the invention shown with a float that is deployed;

(7) FIG. 7 is a section of an aircraft of the invention provided with an angled rod; and

(8) FIG. 8 is a view of an aircraft of the invention provided with an apron sheet secured to a deployed float.

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

DETAILED DESCRIPTION OF THE INVENTION

(10) It should be observed that three mutually orthogonal directions X, Y, and Z are shown in some of the figures, namely a first direction X, a second direction Y, and a third direction Z.

(11) FIG. 1 shows an aircraft 1 of the invention.

(12) The aircraft comprises a fuselage 2 extending lengthwise from a front end 2 to a rear end. The fuselage 2 also extends widthwise from a left flank 2 to a right flank, and in elevation from a bottom portion towards a top portion.

(13) The bottom portion is conventionally provided with landing gear, while the top portion may carry a rotor for providing lift and indeed propulsion. The bottom portion may include a lower section defined in particular by the floor of a cabin and the outer shell of the fuselage.

(14) The aircraft 1 is provided with a buoyancy system 10 of the invention in order to be able to land on water.

(15) Such a buoyancy system is provided with at least one float, e.g. with at least two floats 15 arranged on either side of the fuselage 2 of the aircraft. Thus, a first float is arranged beside the left flank of the aircraft, while a second float is arranged beside the right flank of the aircraft.

(16) The floats may be paired. Under such circumstances, the floats of a pair may be arranged symmetrically on either side of an anteroposterior plane of symmetry of the aircraft in a stable position of the aircraft. For example, the aircraft may have a single pair of floats 15.

(17) The floats are inflatable floats. Other than during stages of landing on water, each float may be folded in a compartment 3 of the aircraft, which compartment is possibly closed in flight by a cover 5 or the equivalent. A float then includes an inflatable bag defined by an outer envelope.

(18) With reference to FIG. 2, each float is inflated by a deployment system 20 for deploying the buoyancy system.

(19) Such a deployment system 20 is provided with at least one actuator 30 communicating with an inflator 25 and a float 15. The deployment device also includes an automatic or manual trigger device 100 for controlling the inflator 25.

(20) The actuator 30 is provided with a cylinder 35 that is fastened to the fuselage 2. To this end, the cylinder 35 may include conventional fastener means 38. The cylinder 35 is thus secured to the fuselage 2, e.g. within a compartment 3.

(21) The cylinder 35 is hollow. Thus, the cylinder may be provided by a blind cylindrical tube 36. The cylindrical tube 36 extends longitudinally from a first end that is closed by an end wall 37 towards a second end that is not closed. The cylindrical tube may also have an opening 39 connected to the inflator 25.

(22) The actuator 30 also possesses a hollow rod 40 that slides relative to the cylinder 35. The rod 40 extends in part inside the cylinder 35 and in part outside the cylinder 35. Thus, the rod 40 may be provided with a hollow tube extending from a first end section present in the cylinder 35 towards a second end section present outside the cylinder.

(23) The rod 40 is movable in translation relative to the cylinder 35 in order to increase or decrease the length of the actuator respectively for the purposes of moving a float away from or towards the fuselage 2. An abutment (not shown) may serve to limit the extent to which the actuator is extended. Such an abutment may comprise a shoulder on the rod co-operating with a shoulder on the cylinder, for example.

(24) Furthermore, the first end section of the rod 40 is secured to a piston 50. This piston 50 consequently defines longitudinal ends of a first chamber 61 inside the cylinder 35, and of a second chamber 62 inside the rod 40.

(25) In contrast, the second end section of the rod 40 is fastened to an envelope 16 of a float 15. Other than during stages of landing on water, the envelope 16 is folded. It should be observed that the rod includes at least one orifice 43 putting the second chamber 62 into communication with the inside 17 of the float 15.

(26) Consequently, the first chamber 61 is in fluid flow communication with an inflator via the opening 39 and possibly via pipework, once the second chamber 62 is in fluid flow communication with a float via each orifice 43 and possibly via pipework.

(27) Furthermore, a channel 63 runs longitudinally through the piston 50 so as to put the first chamber 61 into fluid flow communication with the second chamber 62. At least one gasket may be interposed between the cylinder 35 and the rod 40 in order to prevent any other fluid flow communication between the first chamber 61 and the second chamber 62.

(28) The deployment device then includes a shutter 70 for shutting or releasing the channel 63. Such a shutter may comprise a finger 71 that is engaged inside the channel 63.

(29) Thus, the actuator may include a finger 71 extending longitudinally inside the cylinder 35 from the end wall 37. When the actuator is retracted, the finger 71 is engaged in the channel in order to prevent fluid flow communication between the first chamber 61 and the second chamber 62. Conversely, when the actuator is extended, at least in part, the finger 71 is no longer engaged in the channel 63, thereby allowing fluid flow communication between the first chamber 61 and the second chamber 62.

(30) During a first stage of operation seeking to deploy a float 15, the inflator conveys a gas to the actuator, which gas may be air or an inert gas, for example. The gas penetrates into the first chamber 61 via the opening 39. Since the channel 63 in the piston is closed by the shutter, the pressure of the gas inside the first chamber increases.

(31) This pressure exerted by the gas on the piston 50 causes the rod to move in translation along arrow F1. The rod, and in particular its second end portion carrying the float, then projects out from the fuselage of the aircraft, as shown in FIG. 4.

(32) At the end of the first stage of operation, the finger 71 is no longer inserted in the channel 63, thus enabling the second stage of operation to be triggered.

(33) During this second stage of operation, as shown in FIG. 3, the gas produced by the inflator is conveyed to the float successively via the first chamber 61, the channel 63, and then the second chamber 62. This gas then serves to inflate the float.

(34) At the end of the second stage of operation, the float is inflated, as shown in FIG. 5.

(35) Optionally during a third stage of operation as shown in FIG. 6, the inflator continues to convey gas to the actuator in order to cause the actuator to be extended fully in the direction of arrow F2.

(36) The inflator thus represents extension means serving to extend the actuator 30 by causing the rod 40 to move in translation relative to the cylinder 35 after a float 15 has been inflated.

(37) Extension of the actuator then takes place during the first stage of operation and also during the third stage of operation. For example, the first stage of operation takes place before landing on water, while the third stage of operation may take place after landing on the water, in order to limit the forces exerted by the water on the actuator while the aircraft is settling on the water.

(38) Furthermore, the deployment device may include at least one strap 80 (shown in FIGS. 5 and 6) for limiting the movements of a float 15 relative to an actuator.

(39) By way of example, the deployment device has a top strap 81 and/or a bottom strap 82 fastened respectively to a top portion and to a bottom portion of the float. The term top and bottom should be considered relative to the gravity direction.

(40) Each strap is then connected to an actuator or to the fuselage of the aircraft.

(41) As a variant, or in addition, the first end section may be a straight portion 41 of the rod, while the second end section 42 may be a section that is angled so as to pass through the center of the float.

(42) With reference to FIG. 7, the rod then passes through the float, thereby serving to limit the freedom of the float to move.

(43) FIG. 8 also shows a deployment device having an apron sheet 85. The apron sheet 85 extends from the float to at least one actuator or to the fuselage of the aircraft. The apron sheet may serve to limit the amount of water that splashes into the cabin 4 of the aircraft.

(44) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described above, 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.

(45) In particular, the buoyancy system may include at least one deployment device. For example, the system may have a single deployment device provided with an inflator that is connected to a plurality of actuators for deploying and inflating all of the floats. Alternatively, the system may have one deployment device per float, each deployment device having at least one inflator connected to at least one actuator.

(46) The inflator may optionally suck out the air present in a float 15 in order to retract such a float after landing on water has terminated.