FR3146874A1 - ARRANGEMENT FOR AIRCRAFT CONTROL LEVER - Google Patents

Abstract

The invention relates to an arrangement, in particular a movable stop for an aircraft throttle lever (1), said arrangement comprising a position adjustment device comprising an adjustment rod (20) intended to be arranged in a housing (22) hollowed out in a support (9) and extending in a plane (A) in a longitudinal direction (L), said adjustment rod (20) having an outer surface provided with at least one threaded portion and carrying at least one flat (21), said flat (21) being formed at a distance from said at least one threaded portion, said at least one threaded portion being intended to cooperate with a tapping formed in said housing (22). According to the invention, said arrangement further comprises a rotation stop device comprising a removable stop pin (30) intended to be inserted into a cylindrical orifice (32) hollowed out in said support (9) and extending in a plane (B) parallel to the plane (A) in a direction (P) orthogonal to said longitudinal direction (L) of said housing (22), said cylindrical orifice (32) and said housing (22) being hollowed out so as to be connected at an internal cavity formed in said support (9), said stop pin (30) comprising a rotation stop flat (31) intended to come into contact with said at least one flat (21) of said adjustment rod (20) at said internal cavity, so that said adjustment rod (20) is blocked in rotation relative to said support (9) around the axis carrying said longitudinal direction (L). Figure 3.

Description

ARRANGEMENT FOR AIRCRAFT CONTROL LEVER Field of invention

The present invention relates to the field of aeronautics, more precisely, to a mechanical stop system which can be applied to all types of screw adjustments, threaded parts, for example to an aircraft throttle lever provided in the cockpit for electrical control.

More particularly, the invention relates to an arrangement, in particular a movable stop, for an aircraft, making it possible to stop a position adjustment device in positive rotation, i.e. to achieve a rotation stop by means of a physical obstacle.

State of the prior art

In aeronautics, it is known to implement position adjustment devices. They are used, for example, in the context of joystick levers having an integrated movable stop and the position of which can be adjusted by means of a position adjustment device, for example comprising a spring constrained according to the desired position of the movable stop. This adjustment is carried out in a conventional manner by rotating the movable stop around an axis of the position adjustment device, so as to, for example, compress a spring or any other means requiring a mechanical stop, and therefore to exert a force on it which varies according to the position of the movable stop.

However, it is necessary to stop the adjustment device in rotation once the position of the movable stop has been reached and therefore once the desired level of force exerted on the spring has been reached, so as to maintain the position of the movable stop.

Currently, in order to stop a position adjustment device from rotating, it is known to use rotation stopping means which can be either reversible or irreversible. Such means are for example described in patent documents DE102010032895 or EP3091240.

In aeronautics, reversible solutions such as the implementation of lock wires, lock washers, or systems preventing unscrewing are commonly used.

An advantage of such solutions is that they allow the adjustment device to be locked in rotation in position with little or no damage to this device as well as to the rotation stop means implemented, in particular if it is desired to be able to subsequently dismantle the rotation stop means. However, a major disadvantage of these solutions is that they are unreliable and that they require the parts to be locked in rotation to be adapted beforehand in order to be able to cooperate with the rotation stop means envisaged.

Another potential drawback is that these solutions very often have rotational play, for example equivalent to the stiffness of the brake wire used or the play of a washer used in the assembly.

Yet another drawback of existing solutions is that they can be cumbersome to implement, especially in the case of a screw that is difficult to access or has little space around it.

In aeronautics, irreversible solutions are also known, such as rotation stops by gluing or welding, particularly for adjusting structural clearances. An advantage of these solutions is that they allow the adjustment device to be locked in rotation in position in both directions of rotation, and this reliably.

However, a major drawback of these solutions is that they prove irreversible, unless the rotation adjustment device, or the support on which it is implemented, is at least partially damaged when the rotation stop means are removed, and therefore risk harming the good performance of the assembly.

There is therefore a need to provide an alternative solution that can provide a positive rotation stop that is removable and reliable, while not deteriorating the performance of the position adjustment device.

In other words, there is a need to provide an alternative solution that provides a rotational stop through a physical obstacle that is removable and reliable, while not deteriorating the performance of the position adjustment device.

The invention aims to remedy at least in part the drawbacks mentioned above relating to the techniques of the prior art.

To this end, the invention relates to an arrangement, in particular a movable stop for an aircraft throttle lever, said arrangement comprising a position adjustment device comprising an adjustment rod intended to be arranged in a housing hollowed out in a support and extending in a plane A in a longitudinal direction L, said adjustment rod having an external surface provided with at least one threaded portion and carrying at least one flat, said flat being formed at a distance from said at least one threaded portion, said at least one threaded portion being intended to cooperate with a tapping formed in said housing.

According to the invention, said arrangement further comprises a rotation stop device comprising a removable stop pin intended to be inserted into a cylindrical orifice hollowed out in said support and extending in a plane B parallel to plane A in a direction P orthogonal to said longitudinal direction L of said housing, said cylindrical orifice and said housing being hollowed out so as to be connected at an internal cavity formed in said support, said stop pin comprising a rotation stop flat intended to come into contact with said at least one flat of said adjustment rod at said internal cavity, so that said adjustment rod is blocked in rotation relative to said support around the axis carrying said longitudinal direction L.

Thus, the invention provides a novel and inventive approach to at least partially solving some of the drawbacks of the prior art.

In particular, with the implementation of a rotation stop device comprising a removable stop pin coming into contact with the position adjustment device, rotation is blocked in both possible directions of rotation.

Furthermore, the implementation of such a rotation stop device requires little adaptation of the parts to be blocked in rotation which are intended to cooperate with the rotation stop device according to the invention.

In fact, a simple cutting of the flat part as well as a drilling of the cylindrical orifice is necessary.

Furthermore, another advantage of the invention is that it allows the rotation stop of the adjustment device to be placed perpendicular to it, and thus allows the mechanical stopping of devices that are difficult to access or whose space around does not allow the implementation of usual solutions.

Finally, another advantage of the rotation stop arrangement of a position adjustment device according to the invention is that it is reversible.

According to a particular aspect of at least one embodiment of the invention, the rotation stop flat is in contact with said flat of said adjustment rod over a length of between 25% and 75% of a diameter of said adjustment rod, preferably between 25% and 50% of said diameter of said adjustment rod.

As a result, the mechanical rotation locking forces are distributed over a sufficiently large surface area to limit the mechanical forces exerted at each point, while not disrupting the operation of the position adjustment device.

According to a particular aspect of at least one embodiment of the invention, said rotation stop flat is inclined relative to said orthogonal direction P at an angle of between 0.5 degrees and 3 degrees, preferably substantially equal to 1.5 degrees.

This also ensures that the rotation stop device and the position adjustment device are held in the respective housings in a reciprocal position.

According to a particular aspect of at least one embodiment, said rotation stop flat has a stepped profile where each of the steps has a different inclination.

Such a stepped profile can help to reinforce the blocking.

According to a particular aspect of at least one embodiment of the invention, said adjustment rod has a plurality of flats uniformly distributed around a periphery of said outer surface of said adjustment rod.

This can help improve the accuracy of the adjustment.

According to a particular aspect of at least one embodiment of the invention, said stop pin is crossed by an at least partially tapped through hole. In addition, said rotation stop device comprises a retaining screw intended to be inserted into said at least partially tapped through hole so as to maintain said rotation stop flat in contact with said flat of said adjustment rod.

This allows the pawn to be mechanically held in the housing by mechanically simple and inexpensive means.

It should be noted that a mechanical stop can also be integrated to hold this retaining screw in the tapped hole.

According to a particular aspect of at least one embodiment of the invention, said at least partially tapped hole has a tapping only in the vicinity of the entrance of said hole.

This makes it easier to extract the said stop pin.

According to a particular aspect of at least one embodiment of the invention, said at least one threaded portion of the adjustment rod has a thread pitch of between 0.2 mm and 1.5 mm, preferably between 0.4 mm and 0.6 mm, preferably substantially equal to 0.5 mm.

This allows for fine adjustment of the position adjustment device.

According to a particular aspect of at least one embodiment of the invention, said adjustment rod has a hollow cylindrical body inside which is housed a preload spring kept constrained between a first end piece intended to come into abutment against a bottom of said housing and a second end piece opposite said first end and coming into abutment against an annular end of said hollow cylindrical body of said adjustment rod.

The invention also relates to a joystick lever for an aircraft, comprising a support forming at least part of a body of said joystick lever, and comprising an arrangement for stopping rotation of a position adjustment device, in particular a movable stop, according to one of the aforementioned embodiments.

The invention also relates to an aircraft, comprising a joystick lever according to the aforementioned embodiment, or an arrangement according to one of the aforementioned embodiments.

Presentation of figures

The invention, as well as the various advantages that it presents, will be more easily understood in the light of the following description of illustrative and non-limiting embodiments thereof, and of the appended drawings among which:
is a schematic perspective view of an aircraft cockpit implementing a joystick lever according to one embodiment of the invention;
is a schematic perspective view of an arrangement according to one embodiment of the invention;

is a schematic perspective view of the arrangement according to the embodiment of the , in partially exploded view;
is a schematic perspective view of the arrangement according to the embodiment of the , in partially exploded view, from an opposite viewing angle;
is a schematic front sectional view of the arrangement according to the embodiment of the ;
is a schematic side sectional view of the arrangement according to the embodiment of the ;
is a schematic front sectional view of the arrangement according to a second embodiment of the invention;
is a schematic side sectional view of the arrangement according to the embodiment of the ;
is a schematic side sectional view of the arrangement according to the embodiment of the , without the rotation stop device;
is a schematic perspective view of the arrangement according to the embodiment of the , in partially exploded view, and
is a schematic perspective view of the arrangement according to the embodiment of the .

Detailed description of an embodiment of the invention

It should be noted that the invention applies to any type of joystick lever, and in particular to joystick levers used in cockpits in the context of electric controls.

More generally, the invention is applicable to any type of mechanical system requiring the stopping of a cylindrical part.

Throughout the description, the terms "upstream" and "downstream" are used in reference to the overall direction of gas flow through the turbomachine in operation.

An aircraft throttle lever 1 provided in the aircraft cockpit for electrical control is illustrated in .

Such a joystick lever 1 comprises a support 9 which forms part or all of a body of the joystick lever.

According to the invention, the joystick lever also comprises an arrangement comprising a position adjustment device. Here, the position adjustment device is implemented to adjust the position of a movable stop.

We now present, in relation to Figures 2 to 6, an arrangement according to a first embodiment of the invention.

As illustrated, the position adjustment device, which is here a movable stop position adjustment device for a joystick lever, comprises an adjustment rod 20 intended to be arranged in a housing 22, visible in the , hollowed out in a support 9, here the body of the lever, and extending in a plane A in a longitudinal direction L.

In this embodiment, this adjustment rod 20 has a hollow cylindrical body 2 inside which is housed a preload spring 200 kept constrained between a first end piece 201 intended to come into abutment against a bottom of the housing 22 and a second end piece 202 opposite the first end 201 and coming into abutment against an annular end of the hollow cylindrical body 2 of the adjustment rod 20.

This annular end is provided so that the second end piece 202 cannot come out entirely from the cylindrical body 2 but only partially projects. The end pieces and the spring form a movable stop whose longitudinal extent is adjustable.

This annular end also makes it possible to form an adjustment stop for the adjustment rod 20 so as to limit the sinking of the hollow cylindrical body 2 into the housing 22. In the , this annular end is separated from the support 9 by a distance X.

This adjustment rod 20 has an external surface provided with a threaded portion intended to cooperate with a tapping formed in the housing 22 so as to adjust the position of the movable stop. This thread makes it possible to block the translation in the direction L.

In this embodiment, the threaded portion has a thread pitch substantially equal to 0.5 mm. Logically, the tapping has a substantially equal thread pitch.

According to other embodiments, the threaded portion could have a thread pitch of between 0.2mm and 1.5mm, preferably between 0.4mm and 0.6mm.

Furthermore, this adjustment rod 20 carries a flat 21. As illustrated, this flat 21 is formed at a distance from the threaded portion.

According to the invention, the arrangement further comprises a rotation stop device comprising a removable stop pin 30 intended to be inserted into a cylindrical orifice 32 hollowed out in the support 9 and extending in a plane B parallel to the plane A, in a direction P orthogonal to the longitudinal direction L of the housing 22.

It should be noted that the cylindrical orifice 32 and the housing 22 are hollowed out so as to be connected at the level of an internal cavity formed in the support 9.

As illustrated, the stop pin 30 comprises, in this embodiment, a rotation stop flat 31 intended to come into contact with the flat 21 of the adjustment rod 20 at the level of the internal cavity, so that the adjustment rod 20 is blocked in rotation relative to the support 9 around the longitudinal direction L.

In other words, the rotation stop flat 31 and the flat 21 of the adjustment rod 20 come into contact at the internal cavity so that the rotation stop flat prevents rotation about the axis carrying the longitudinal direction L, in both directions of rotation, of the adjustment rod 20 relative to the support 9.

Here, the rotation stop flat 31 is in contact with the flat 21 of the adjustment rod 20 over a length of between 25% and 50% of a diameter of the adjustment rod 20.

According to other embodiments, the rotation stop flat could be in contact with the flat of the adjustment rod over a length of between 25% and 75% of a diameter of the adjustment rod.

In the first illustrated embodiment, and so as to facilitate the insertion of the stop pin 30 into the cylindrical orifice 32, the rotation stop flat 31 is inclined relative to the orthogonal direction P at an angle substantially equal to 1.5 degrees.

According to other alternatives, the rotation stop flat 31 could be inclined relative to the orthogonal direction P at an angle between 0.5 degrees and 3 degrees.

Furthermore, according to another alternative not shown, the rotation stop flat could have a stepped profile where each of the steps has a different inclination. Such a stepped profile could in particular make it possible to reinforce the blocking, or even make the blocking irreversible if necessary.

As can be seen in particular in Figures 3 and 4, the stop pin 30 is here crossed by a threaded through hole 33. Furthermore, the rotation stop device comprises a retaining screw 34 which is intended to be inserted into this threaded through hole 33 so as to maintain the rotation stop flat 31 in contact with the flat 21 of the adjustment rod 20.

Such a retaining screw 34 inserted into the through-tapped hole 33 is more particularly illustrated in figures 2 and 5.

According to other embodiments, it would also be possible to provide holding means to replace the holding screw, provided that these means provide the same function.

It should be noted that the insertion of the pin could also be carried out by means other than a screw, such as a tight assembly, a press assembly, a nitrogen pressure assembly.

It should be noted that a mechanical stop can also be integrated to hold the retaining screw in the tapped hole.

We now present, in relation to Figures 7 to 11, an arrangement according to a second embodiment of the invention.

In this embodiment, the features common to the first embodiment are not detailed again.

As illustrated, the position adjustment device, which is here also intended to adjust the position of a movable stop, comprises an adjustment rod 20’ intended to be arranged in a housing 22’ hollowed out in a support 9 and extending in a plane A in the longitudinal direction L.

In this embodiment, the adjustment rod 20’ has an outer surface provided with a threaded portion and carrying a plurality of flats 21’ uniformly distributed around the perimeter of the outer surface of this adjustment rod 20’, at a distance from the threaded portion.

Here, this 20’ adjustment rod has a hexagonal head intended to cooperate with a screwing or unscrewing key so as to adjust the position of the movable stop.

As in the first embodiment, the arrangement further comprises a rotation stop device comprising a removable stop pin 30 intended to be inserted into a cylindrical orifice 32 hollowed out in the support 9 and extending in a plane B parallel to the plane A in a direction P orthogonal to the longitudinal direction L of the housing 22', the cylindrical orifice 32 and the housing 22' being hollowed out and connected at the level of an internal cavity formed in the support 9.

As illustrated, and similarly to the first embodiment, the stop pin 30 comprises a rotation stop flat 31 intended to come into contact with one of the flats 21' of the adjustment rod 20' at the level of said internal cavity, so that the adjustment rod 20' is blocked in rotation relative to the support 9 in the longitudinal direction L.

The fact here of having an adjustment device having a plurality of flats makes it possible to obtain a fine adjustment of the adjustment device in position because the rotation stop can be made at the level of several flats.

Claims (10)

Arrangement, in particular of a movable stop for an aircraft throttle lever (1), said arrangement comprising a position adjustment device comprising an adjustment rod (20) intended to be arranged in a housing (22) hollowed out in a support (9) and extending in a plane (A) in a longitudinal direction (L), said adjustment rod (20) having an external surface provided with at least one threaded portion and carrying at least one flat (21), said flat (21) being formed at a distance from said at least one threaded portion, said at least one threaded portion being intended to cooperate with a tapping formed in said housing (22),
characterized in that said arrangement further comprises a rotation stop device comprising a removable stop pin (30) intended to be inserted into a cylindrical orifice (32) hollowed out in said support (9) and extending in a plane (B) parallel to the plane (A) in a direction (P) orthogonal to said longitudinal direction (L) of said housing (22), said cylindrical orifice (32) and said housing (22) being hollowed out so as to be connected at the level of an internal cavity formed in said support (9),
said stop pin (30) comprising a rotation stop flat (31) intended to come into contact with said at least one flat (21) of said adjustment rod (20) at said internal cavity, so that said adjustment rod (20) is blocked in rotation relative to said support (9) around the axis carrying said longitudinal direction (L). Arrangement according to claim 1, characterized in that said rotation stop flat (31) is in contact with said flat (21) of said adjustment rod (20) over a length between 25% and 75% of a diameter of said adjustment rod (20), preferably between 25% and 50% of said diameter of said adjustment rod (20). Arrangement according to one of claims 1 or 2, characterized in that said rotation stop flat (31) is inclined relative to said orthogonal direction (P) at an angle between 0.5 degrees and 3 degrees, preferably substantially equal to 1.5 degrees. Arrangement according to claim 3, characterized in that said rotation stop flat (31) has a stepped profile where each of the steps has a different inclination. Arrangement according to one of claims 1 to 4, characterized in that said adjustment rod (20) has a plurality of flats (21) uniformly distributed around a periphery of said outer surface of said adjustment rod (20). Arrangement according to one of claims 1 to 5, characterized in that said stop pin (30) is crossed by an at least partially tapped through hole (33), and in that said rotation stop device comprises a retaining screw (34) intended to be inserted into said at least partially tapped through hole (33) so as to maintain said rotation stop flat (31) in contact with said flat (21) of said adjustment rod (20). Arrangement according to one of claims 1 to 6, characterized in that said at least one threaded portion of said adjustment rod (20) has a thread pitch of between 0.2mm and 1.5mm, preferably between 0.4mm and 0.6mm, preferably substantially equal to 0.5mm. Arrangement according to one of claims 1 to 7, characterized in that said adjustment rod (20) has a hollow cylindrical body (2) inside which is housed a preload spring (200) kept stressed between a first end piece (201) intended to come into abutment against a bottom of said housing (22) and a second end piece (202) opposite said first end (201) and coming into abutment against an annular end of said hollow cylindrical body of said adjustment rod (20). Joystick lever (1) for an aircraft, comprising a support (9) forming at least part of a body of said joystick lever, characterized in that it comprises an arrangement for stopping rotation of a position adjustment device, in particular a movable stop, according to one of claims 1 to 8. Aircraft, comprising a throttle lever (1) according to claim 9, or an arrangement according to one of claims 1 to 8.