TURBOMACHINE NACALE LOCK
The lock mechanism with a worm screw and nut enables efficient, rapid pre-tension adjustment of turbomachine nacelle locks, addressing the inefficiencies of existing systems by allowing independent adjustment without repeated lock operations and enhancing accessibility.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- SAFRAN NACELLES
- Filing Date
- 2024-12-20
- Publication Date
- 2026-06-26
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Title of the invention: TURBOMACHINE NACELLE LOCK Technical field of the invention
[0001] The present invention relates to a lock for a turbomachine nacelle, particularly an aircraft turbomachine nacelle, a nacelle equipped with such a lock, and a method for adjusting such a lock. The lock is configured to lock cowlings in the closed position when in a locked configuration and to allow the cowlings to open when in an unlocked configuration. Technical background
[0002] The technical background includes in particular the document FR-A1-3 015 435.
[0003] Aircraft engine assemblies generally comprise a nacelle forming a generally annular outer casing housing a turbomachine arranged along the longitudinal axis of this nacelle. The turbomachine receives fresh air from the upstream side and expels hot gases from fuel combustion, which provide thrust, on the downstream side.
[0004] An aircraft turbomachine generally comprises, from upstream to downstream, a fan and several modules such as a low-pressure compressor followed by a high-pressure compressor, an annular combustion chamber, a high-pressure turbine followed by a low-pressure turbine, which drive the corresponding low- or high-pressure compressor, and a gas ejection system. Upstream and downstream are defined with respect to the normal direction of gas flow in a flow channel (from upstream to downstream).
[0005] In the case of turbofan engines, the high- and low-pressure sections are traversed by a primary airflow, and the fan produces a secondary airflow that circulates within the turbofan, between a casing and a nacelle or outer shell of the turbofan, in a cold-flow channel. At the nozzle outlet, the gases from the primary flow are mixed with the secondary flow to produce a propulsion force, the secondary flow providing the majority of the thrust in normal operation, resulting in a direct jet.
[0006] Some nacelles include a thrust reversal system that at least partially closes the annular stream of cold air and rejects the secondary flow forward, forming a reverse jet that generates a braking thrust for the aircraft. One known type of nacelle comprises two half-hoods or cowls covering the midsection surrounding the secondary flow fan, connected to each other by a hinge. having a longitudinal axis located in the upper part, so as to allow the lower parts of these hoods to be opened for maintenance operations.
[0007] The hoods are held in the closed position, generally in the lower part, by locks which achieve a tangential clamping between these two hoods.
[0008] In a known manner, these locks comprise a hook and a stirrup including a loop or a bar, each fixed to one of the covers. In a locked position, the hook cooperates with the loop or bar in a closed position of the covers. In an unlocked position, the hook is disengaged from the loop or bar, allowing the covers to be opened.
[0009] The loop or bar is located at one longitudinal end of a threaded rod that receives a nut for adjusting the pre-tension or pre-load of the lock. This pre-load adjustment nut can be located on the hook or loop / bar side of the lock. The nut can thus be directly integrated onto the hook or onto a bracket incorporating the loop or bar, onto which the hook locks.
[0010] The nut is screwed or unscrewed to adjust the position of the loop or bar relative to the hook, thereby varying the force required to lock the hook onto and unlock it from the loop or bar, and thus to move from the locked position to the unlocked position, and vice versa. This nut therefore allows adjustment of the preload in the mechanism once locked.
[0011] The locks are generally operated manually by an operating handle to open and / or close them.
[0012] As is known, access to the nuts requires opening the lock handle. After opening the lock, the nut must be used as an adjustment knob to adjust the caliper, and once this knob is turned (to increase or decrease the pre-tension), the value of this pre-tension must then be checked by closing the lock using a force measuring tool, such as a spring scale.
[0013] In other words, adjusting the pre-tension requires opening the lock to access the nut and then closing the lock with the measuring tool on the handle to measure the closing force. The force exerted on the handle during closing is then converted into a pre-tension force in the lock.
[0014] This pre-tension adjustment step is therefore lengthy, particularly because the lock must be opened and closed several times to adjust the setting dichotomously until the desired pre-tension value is obtained. It is also tedious, especially since the lock must be closed with the measuring tool to measure the force exerted on the handle, and the accessibility of the lock handles is not always optimal.
[0015] The objective of the present invention is therefore to propose a gondola lock that makes it possible to overcome at least some of these drawbacks of the prior art. Summary of the invention
[0016] The invention relates to a lock for a turbomachine nacelle comprising first and second cowlings, the lock comprising: - a first part intended to be fixed to the first cover and comprising a hook and a handle for actuating the hook, the hook being movable from an unlocked position to a locked position, the actuating handle being connected to the hook and being movable from a closed position to an open position, the movement of the actuating handle from its closed position to its open position causing the hook to move from its locked position to its unlocked position, and vice versa, and
[0017] - a second part intended to be fixed to the second cover and comprising a bracket comprising a loop or bar that is configured to cooperate with said hook,
[0018] the first or second part comprising a threaded rod which is connected to said hook or to said loop or bar, this threaded rod receiving an adjusting nut whose screwing / unscrewing allows adjustment of the position of the loop or bar of the caliper vis-à-vis the hook, or vice versa,
[0019] the hook being capable of engaging with the loop or bar of the stirrup when the hook is moved from its unlocked position to its locked position, and of disengaging from the loop or bar of the stirrup when the hook is moved from its locked position to its unlocked position,
[0020] According to the invention:
[0021] - the nut comprises external teeth, and
[0022] - the lock further comprises a worm screw which includes an external thread meshed with the external teeth of the nut so that a rotation of the worm in one direction around its axis causes the nut to tighten, and in a second opposite direction around its axis causes the nut to loosen.
[0023] Thanks to the cooperation between the nut and the worm screw of the lock, it is possible to adjust the position of the loop or bar of the stirrup vis-à-vis the hook, i.e. to adjust the pre-tension of the lock independently of the position of the lock, i.e. independently of whether the lock is in the closed and locked position or open and unlocked.
[0024] The lock of the invention thus makes it possible to avoid the multiple opening / closing operations of the lock to adjust the pre-tension setting.
[0025] The invention thus allows for a simple, precise, and rapid pre-tension adjustment, for example by using a torque wrench to tighten / loosen the worm gear. When using a torque wrench (or equivalent torque measuring tool), the wrench is triggered at the desired torque and informs the operator that the adjustment has been made simply and efficiently.
[0026] The invention also makes it possible to quickly reduce the pre-tension in the lock, thanks to the worm screw, which in particular facilitates the opening and closing of the lock handles.
[0027] In addition to allowing the nut to rotate, the worm screw also prevents the nut from rotating. This second anti-rotation function of the worm screw ensures, in particular, that the nut remains in a fixed position (until an operator acts on the worm screw) so as to guarantee that the pre-tension setting remains at the defined value.
[0028] The lock according to the invention may comprise one or more of the following features, taken individually or in combination with each other in all technically possible combinations:
[0029] - one of the covers or a cover wall covers the nut and includes an opening passing through at the nut, this orifice being suitable for a tool to be passed through to rotate the worm screw.
[0030] - the hood or the hooding wall containing the opening is at a distance predetermined length of the worm screw, which is preferably greater than a length of the worm screw.
[0031] — the hood or the hooding wall includes a plug that is movable from a from the closed position of the orifice to an open position of the orifice, the stopper being stressed by at least one elastic element such as a spring in its closed position.
[0032] - the worm screw has its axis which is located in a plane perpendicular to the axis of tightening / unscrewing the nut.
[0033] - the worm screw and the nut are mounted in the same housing of the first or of the second part.
[0034] - the housing is formed by a case of generally parallelepiped shape, this case comprising two side walls through which said threaded rod passes and between which the nut is located.
[0035] - the worm screw comprises a first longitudinal end guided in rotation in a socket or orifice of the first or second part, and a second longitudinal end, opposite the first end, which includes a head suitable for cooperating with a tool for rotating the worm screw.
[0036] — the socket or orifice is located in or on a wall of the housing which extends between the two side walls.
[0037] — the housing is open on the side opposite the socket or the orifice.
[0038] - the worm screw passes through an opening in the housing and has its second end which is located outside the case.
[0039] — the head of the worm screw includes a recess.
[0040] The invention also relates to a nacelle for a turbomachine, comprising first and second hoods, as well as a lock as described above, the first part of the lock being fixed to the first hood, and the second part of the lock being intended to be fixed to the second hood.
[0041] The invention also relates to a turbomachine, in particular for aircraft, comprising at least one nacelle as described above.
[0042] The invention further relates to a method for adjusting a lock as described above, comprising the following steps:
[0043] a) moving the actuating handle from its closed position to its open position so as to cause the hook to move from its locked position to its unlocked position,
[0044] b) rotating the worm screw so as to screw or unscrew the nut and adjust the tension of the lock.
[0045] The method includes, for example, between steps a) and b), a step of inserting a tool through the opening of the hood or the hood wall, and engaging this tool with the worm screw in order to rotate it. Brief description of the figures
[0046] The present invention will be better understood and other details, features and advantages of the present invention will become more apparent upon reading the description of a non-limiting example that follows, with reference to the accompanying drawings in which: [Fig.1] The [Fig.1] is a schematic overview in axial section of a turbomachine nacelle; [Fig.2] The [Fig.2] is a schematic perspective view of a gondola lock; [Fig.3] The [Fig.3] is a schematic cross-sectional view of a lock in a locked position;
[0047] [Fig.4] The [Fig.4] is a schematic cross-sectional view of the lock of the [Fig.2] in an unlocked position; [Fig.5] The [Fig.5] is a schematic perspective view of part of the lock including a stirrup, a nut and a worm screw;
[0048] [Fig.6] The [Fig.6] is a schematic cross-sectional view of the nut and worm gear;
[0049] [Fig.7] Fig.7 is a schematic perspective view of the locking part of the [Fig.5] positioned on the aircraft nacelle, the latter comprising an opening and a plug in the closed position;
[0050] [Fig.8] [Fig.8] is similar to [Fig.7], with the cap in the open position; and
[0051] [Fig.9] [Fig.9] is a view similar to [Fig.7], showing another mode of realization of the invention. Detailed description of the invention
[0052] Figure 1 shows a nacelle 10 containing a turbomachine supported by a pylon 4 fixed under the wing of an aircraft. The nacelle 10 comprises a front section 6 including a streamlined air inlet, a central section 2 surrounding a cold air fan 14, and a rear section 8 including, in particular, a thrust reverser, for example with grids or doors. The nacelle 10 forms an external profile of the annular duct 12 guiding the flow of cold air, and an aerodynamic outer fairing.
[0053] The nacelle 10 has a longitudinal axis A and an annular shape about this axis. The central section 2 of the nacelle comprises two external cover hoods, arranged symmetrically with respect to a vertical axial plane P (which is, for example, the cutting plane of [Fig. 1]). These hoods can open laterally by pivoting about a hinge comprising a longitudinal axis located at the top and parallel to the longitudinal axis A of the nacelle 10. The rear section 8 comprises two rear lateral parts or hood walls, which close onto each other along the same axial plane P of symmetry.
[0054] The invention applies in particular to this rear section 8 or to the central section 2 or any other sections. Generally, the invention applies to any nacelle of a turbomachine comprising two cowlings and / or two cowling walls that can open and close against each other, and in particular to the nacelle 10 illustrated in [Fig. 1]. For example, these two cowlings may be fan cowlings or reversing cowlings that slide rearward during a thrust reversal phase.
[0055] Figure 2 is a bottom view of the nacelle 10 showing at the top the two front cowlings 20, 22 and at the bottom the two cowling walls 24, 26, these cowlings and cowling walls, when closed, joining along the plane of symmetry P. The two cowling walls 24, 26 are clamped to each other in a tangential direction by several latches, including a latch 50 of the invention. The latch of the invention could also clamp any other wall or cowling of an aircraft nacelle, for example the cowlings 20, 22.
[0056] The lock 50 includes, in particular, an operating handle 28, which is actuated in a transverse plane. In this embodiment, when this lock 50 is locked and the front covers 20, 22 are closed, the handle 28 is positioned so fitted in an external transverse cut extending over these two hoods, at the limit of the hood walls 24, 26. The free end of the handle 28 which pivots in the operation, shown on the right of the figure, has a notch which offsets it slightly towards the axis of the nacelle, to come below the right front hood 20.
[0057] Figures 3 and 4 show the handle 28, for example, fixed by pivots to the left-hand side panel 26, acting in particular via a rocker 34 on a locking lever of the latch 50. The locking lever here comprises a main hook 30 that engages a loop 33 located at the end of a threaded rod 62 fixed to the right-hand side panel 24. The latch 50 further comprises, for example, a safety hook 36. Once the handle 28 is fully closed, the safety hook 36, pivotally fixed to the handle 28, locks automatically by the action of a spring on the main hook 30 or another element of the latch 50. To open the handle 28, it is necessary, for example, to press on a push button 38 of the safety hook 36 located in the outer plane of the handle 28, in order to release the hook and free the handle, which can then pivot.
[0058] In this embodiment, the outer surface of the handle 28 fitted in the cutout of the hoods 20, 22, comes substantially at the level of the surface of these hoods in order to obtain an aerodynamic continuity of the outer surface of the nacelle.
[0059] The free end of the handle 28 may have a recess 40 that fits inside the right front cover 20, forming a substantially flat surface parallel to this cover with a gap, so as to prevent any contact between this cover and the handle. A similar gap exists between the closed handle 28 and the edges of the cutout.
[0060] With the front cover 20 closed, the handle 28 cannot be opened, nor can it be closed if it is open. Furthermore, since the handle 28 is held open by a spring, and the main hook 30 is tilted downwards, extending radially outwards from the cover walls 24, 26 that support it, the cutouts in the covers 20, 22 ensure that, in all cases, when they are closed or dropped, they do not strike any element of the lock, in particular the handle and the hook.
[0061] The lock 50 essentially comprises two parts 52, 54 which are intended to be fixed respectively to two hoods, such as the hoods 20, 22, or to two hooding walls 24, 26, as in the example above.
[0062] The first part 52 of the lock 50 is here that comprising the hook 30 and the operating handle 28.
[0063] The hook 30 is movable from an unlocked position, comparable to that of [Fig.4], to a locked position illustrated in [Fig.3].
[0064] The actuating handle 28 is connected to the hook 30, for example by a three-point mechanism, and is movable from an illustrated closed position to [Fig.3], until an opening position comparable to that of [Fig.4]. This movement can be achieved by pivoting or tilting.
[0065] The movement of the operating handle 28 from its closed position to its open position causes the movement of the hook 30 from its locked position to its unlocked position, and vice versa, thanks to the aforementioned mechanism.
[0066] The first 52 or the second part 54 (here the second part 54) of the lock 50 includes a stirrup 56.
[0067] The stirrup 56 here includes the loop 33 which is configured to cooperate with the hook 30. The first part 52 or the second part 54 (here the second part 54) includes the threaded rod 62 which is connected to the hook 30 or to said loop 33 (here the loop 33 as explained previously). In particular, it is the stirrup 56 that includes the threaded rod 62. This threaded rod 62 receives an adjusting nut 66 of the lock 50, the tightening / loosening of which allows the position of the loop 33 of the stirrup 56 to be adjusted relative to the hook 30, or vice versa (according to the double arrow Fl in Figures 3 and 4). The threaded rod 62 is mounted axially sliding in the nut 66, along an elongation axis C of the threaded rod 62 (equivalent to a screwing / unscrewing axis C of the nut 66).
[0068] The stirrup 56 is advantageously axially mobile in an orifice of the nut 66, from a rearward position in which the nut 66 is axially away from the loop 33 and an advanced position in which the nut 66 is close to the loop 33.
[0069] In this application, the term "stirrup" means any mechanical element configured to cooperate with the hook 30. The stirrup 56 may, for example, comprise the loop 33 and the threaded rod 62 (as explained previously) or a bar 33' (illustrated [Fig. 9]) with which the hook 30 can cooperate. In the latter case, it is the hook 30 that comprises the threaded rod 62.
[0070] The hook 30 is able to engage on the loop 33 of the stirrup 56 when the hook 30 is moved from its unlocking position ([Fig.3]) to its locking position ([Fig.4]), and to disengage from the loop 33 of the stirrup 56 when the hook 30 is moved from its locking position to its unlocking position.
[0071] More precisely, moving the actuating handle 28 from its closed position to its open position causes the hook 30 to move from its locked position to its unlocked position and disengages the hook 30 from the loop 33, and conversely, moving the actuating handle 28 from its open position to its closed position causes the hook 30 to move from its unlocked position to its locked position and engages the hook 30 in the loop 33.
[0072] According to the invention, the lock 50 comprises a worm screw 70. As can be seen in particular in Figures 5 to 9, the worm screw 70 comprises an external thread 71 meshed with an external tooth (or thread) 67 of the nut 66 so that a rotation of the worm screw 70 in a first direction around its axis V causes the nut 66 to tighten, and in a second opposite direction around its axis V causes the nut 66 to loosen. The external tooth 67 allows the nut 66 to rotate.
[0073] In this way it is possible for an operator to adjust the position of the nut 66 and therefore the pre-tension of the lock 50 by acting on the worm screw 70, in particular with the aid of a tool 100, for example a torque wrench (or other portable electric type tools, such as a screwdriver with torque detector, or other manual torque measuring tools). The worm gear 70 includes, for example, a head 74 adapted to cooperate with the tool 100 for rotating the worm gear 70. The head 74 can be flush with the aerodynamic surface of the cowlings 20, 22, or the cowling walls 24, 26 (as illustrated in Figures 3 and 4), allowing direct access with the tool 100. Alternatively, the head 74 can be located at a certain distance D from the cowlings 20, 22, or the cowling walls 24, 26 (as illustrated in Figures 7 to 9). In both cases, the locking mechanism 50 of the invention optimizes aerodynamic performance.
[0074] The worm screw 70 and the nut 66 are mounted in particular in the same housing 80 of the first or second part 52, 54 (the second part 54 in the embodiments illustrated in figures 3 and 4).
[0075] As can be seen in particular in [Fig. 5], the housing 80 is formed by a casing 90, generally parallelepiped in shape. The shape of the casing could, however, be different (elliptical, hexagonal, etc.). This casing 90 comprises, in particular, two lateral walls 91, 92 through which the threaded rod 62 passes and between which the nut 66 is located. The casing 90 surrounds, for example, the nut 66 in order to maintain the position of the threaded rod 62 relative to the nut 66.
[0076] The worm screw 70 includes, for example, a first longitudinal end 72, in particular guided in rotation in a sleeve 75 or an orifice of the first or second part 52, 54, and in particular a second longitudinal end 73, opposite the first end 72, which includes the head 74. The sleeve 75 or the orifice may be located in or on a wall 93 of the housing 90 which extends between the two lateral walls 91, 92, so as to allow in particular cooperation between the worm screw 70 and the nut 66.
[0077] The housing 90 is, for example, open on the side opposite the bushing 75 or the orifice, so as to allow the worm screw 70 to enter the housing 90. The housing 90 includes in particular an opening 95, through which the worm screw 70 passes. This allows the worm screw to have its second end 73 located outside the housing 90, facilitating access to the worm screw for an operator.
[0078] The head 74 of the worm gear 70 includes, for example, a recess 78 that further facilitates access to the worm gear 70 for an operator. The recess 78 may be flush with the aerodynamic surface of the cowlings 20, 22, or the cowling walls 24, 26 (as illustrated in Figures 3 and 4) or be located at a certain distance D from the cowlings 20, 22, or the cowling walls 24, 26 (as illustrated in Figures 7 to 9). The recess 78 may be male, for example, hexagonal. In this case, the worm gear 70 can be rotated using a socket, particularly a hexagonal one. Alternatively, the recess 78 may be female. In this case, the worm gear 70 can be rotated using an Allen® or Torx® wrench. The female imprint 78 can also be square in shape.
[0079] The worm screw 70 has in particular its axis V which is located in a plane S perpendicular to the screwing / unscrewing axis C of the nut 66.
[0080] The worm screw 70 ensures the rotational locking of the nut 66. By preventing the rotation of the nut 66, the worm screw 70 thus secures the adjustment of the lock 50.
[0081] According to the embodiments illustrated in Figures 7 to 9 (and unlike those illustrated in Figures 3 and 4), the lock 50 is located at a certain distance from the covers 20, 22 and / or the cover walls 24, 26. In this case, one or both of the covers 20, 22 and / or one or both of the cover walls 24, 26 covers the nut 66. This cover or these covers 20, 22 and / or this cover wall or these covers include in particular a through hole 110 at the center of the nut 66. This hole 110 is adapted to allow passage through the tool 100 ([Fig. 8]) for rotating the worm screw 70.
[0082] This solution makes it possible to optimize the aerodynamic surface of the nacelle.
[0083] The hood 20, 22 or the covering wall 24, 26 having the orifice 110 is located at the predetermined distance D from the worm gear 70. The distance D is a distance allowing the opening and closing of the hood 20, 22 without interfering with the locking mechanism 50. The distance D is preferably greater than a length e of the worm gear 70. In an embodiment not shown, the hood 20, 22 or the covering wall 24, 26 having the orifice 110 are located at a distance very close to the worm gear 70, in particular a distance D less than the length e of the worm gear 70, as for example in the case of a sliding hood or covering.
[0084] The cover 20, 22 or the cover wall 24, 26 includes, for example, a plug 111 which is movable from a closed position of the orifice 110 ([Fig. 7]) to an open position of the orifice 110 ([Fig. 8]). The plug 111 is, in particular, subjected by at least one elastic element 112, such as a spring, in its closed position so as to remain closed by default.
[0085] In the variant of the invention illustrated in [Fig.9], it is not the stirrup that is connected to the threaded rod 62 but the hook 30. The hook 30 can be connected to a longitudinal end of the threaded rod 62 and an assembly with the adjusting nut 66, similar to that described above, can be adopted.
[0086] Furthermore, in this figure, the stirrup 56 is formed by a simple bar 33' which is configured to cooperate with the hook 30 in the same way that the loop 33 cooperates with the hook 30 in the previous example.
[0087] The first part 52 here comprises the threaded rod 62 which is connected to the hook 30. In particular, it is the hook 30 that includes the threaded rod 62. This threaded rod 62 receives the adjusting nut 66 of the lock 50, the screw / unscrew of which allows the position of the bar 33' of the bracket 56 to be adjusted relative to the hook 30, or vice versa (according to the double arrow Fl in [Fig. 9]), thus ensuring the same function as in the previous embodiments
[0088] The other elements of the lock 50 of the invention remain similar here to the embodiments presented previously.
[0089] The invention also relates to a method for adjusting the lock 50 as described above. The method comprises in particular the following steps:
[0090] a) movement of the actuating handle 28 from its closed position to its open position so as to cause the hook 30 to move from its locked position to its unlocked position,
[0091] b) rotating the worm screw 70 so as to screw or unscrew the nut 66 and to adjust the tension of the lock 50.
[0092] The method includes, in particular, between steps a) and b), a step of inserting the tool 100 through the orifice 110 of the hood 20, 22 or of the hooding wall 24, 26, and engaging this tool 100 on the worm screw 70 in order to rotate it.
[0093] The lock according to the invention has many advantages, including:
[0094] - the reduction in the lock adjustment time due to the fact that it is no longer necessary to open and close the lock to adjust the pre-tension.
[0095] - facilitating the adjustment of the lock, in particular triggering the tool, including a torque wrench, set to the desired torque.
[0096] - the final pre-tension can be applied easily and quickly to the last moment. It will then be possible to significantly reduce the pre-tension to facilitate intermediate opening and closing of lock handles.
[0097] - Maximized aerodynamics.
Claims
Demands
1. A lock (50) for a turbomachine nacelle comprising first and second cowlings (20, 22), the lock (50) comprising: - a first part (52) for attachment to the first cowling (20) and having a hook (30) and a handle (28) for actuating the hook (30), the hook (30) being movable from an unlocked position to a locked position, the actuating handle (28) being connected to the hook (30) and being movable from a closed position to an open position, the movement of the actuating handle (28) from its closed position to its open position causing the hook (30) to move from its locked position to its unlocked position, and vice versa, and - a second part (54) for attachment to the second cowling (22) and having a bracket (56) having a loop (33) or a bar (33') which is configured to cooperate with said hook (30),the first or second part (52, 54) comprising a threaded rod (62) which is connected to said hook (30) or to said loop (33) or bar (33'), this threaded rod (62) receiving an adjusting nut (66) the screwing / unscrewing of which allows the position of the loop (33) or bar (33') of the caliper (56) to be adjusted vis-à-vis the hook (30), or vice versa, the hook (30) being able to engage on the loop (33) or bar (33') of the caliper (56) when the hook (30) is moved from its unlocking position to its locking position, and to disengage from the loop (33) or bar (33') of the caliper (56) when the hook (30) is moved from its locking position to its unlocking position, characterized in that: - the nut (66) comprises an external toothing (67),and - the lock (50) further comprises a worm screw (70) which includes an external thread (71) meshing with the external teeth (67) of the nut (66) such that a rotation of the worm screw (70) in a first direction around its axis (V) causes the nut (66) to tighten, and in a second opposite direction around its axis (V) causes the nut (66) to loosen.
2. Lock (50) according to claim 1, wherein one of the covers (20, 22) or a cover wall (24, 26) covers the nut (66) and includes a through hole (110) at the nut (66), this hole (110) being suitable for a tool (100) to pass through for rotating the worm screw (70).
3. Lock (50) according to claim 2, wherein the hood (20, 22) or the hooding wall (24, 26) having the orifice (110) is at a predetermined distance (D) from the worm gear (70), which is preferably greater than a length (e) of the worm gear (70).
4. Lock (50) according to any one of the preceding claims, wherein the worm screw (70) has its axis (V) which is located in a plane (S) perpendicular to the screwing / unscrewing axis (C) of the nut (66).
5. Lock (50) according to any one of the preceding claims, wherein the worm screw (70) and the nut (66) are mounted in the same housing (80) of the first or second part (52, 54), the housing (80) being formed by a case (90) of generally parallelepiped shape, this case (90) comprising two lateral walls (91, 92) which are traversed by said threaded rod (62) and between which is located the nut (66).
6. Lock (50) according to any one of the preceding claims, wherein the worm (70) comprises a first longitudinal end (72) guided in rotation in a bushing (75) or an orifice of the first or second part (52, 54), and a second longitudinal end (73), opposite the first end (72), which comprises a head (74) adapted to cooperate with a tool (100) for rotating the worm (70).
7. Lock (50) according to all claims 5 and 6, wherein the worm screw (70) passes through an opening (95) in the housing (90) and has its second end (73) which is located outside the housing (90).
8. Nacelle (10) for a turbomachine, comprising first and second cowls (20, 22), and a latch (50) according to any one of the preceding claims, the first part (52) of the latch (50) being fixed to the first cowl (20), and the second part (54) of the latch (50) being intended to be fixed to the second cowl (22).
9. A method for adjusting a lock (50) according to any one of claims 1 to 7, wherein it comprises the following steps: a. moving the actuating handle (28) from its closed position to its open position
10. so as to cause the hook (30) to move from its locked position to its unlocked position, b. rotating the worm screw (70) so as to screw or unscrew the nut (66) and to adjust the tension of the lock (50). Method according to claim 9, wherein, the lock (50) being as defined in claim 2 or 3, it comprises, between steps a) and b), a step of inserting a tool (100) through the orifice (110) of the hood (20, 22) or of the hood wall (24, 26), and engaging this tool (100) on the worm screw (70) in order to rotate it.