Capture pin for locking hook

Abstract

The invention relates to a capture pin (100) intended to be mounted on a movable element (3) to be hooked by a locking hook (4) with the intention of fixing the movable element in a given position, the capture pin comprising: a body (101) provided with a longitudinal opening (120) enabling the body to be mounted on the main shaft (1) of the movable element; and a rotating outer surface (109, 110, 111) having a central portion (110) having a convex profile cooperating with the hook. According to the invention, the central portion of the outer surface is formed on a central ring (107) mounted so as to rotate freely on a central bearing surface (103) of the body. The invention also relates to an aeronautical device, an undercarriage and a method for mounting such a capture pin.

Description

Technical Field

[0001] The present invention relates to a capture pin for a locking hook. Background Art

[0002] The aircraft comprises a number of movable elements such as landing gear, doors, wing tips between deployed and retracted positions. These movable elements are provided with a capture pin adapted to at least one of the above positions to be hooked by a locking hook supported by the aircraft structure, thereby fixing the movable element in place.

[0003] The catch pin is usually in the form of a rotor with an axial opening to be received in free rotation on a spindle supported by the movable element so that it can roll on the hook during parking or release. However, cases have been observed where the catch pin gets stuck on the spindle, thereby creating friction between the catch pin and the hook during movement of the hook, sometimes making it difficult to release the catch pin.

[0004] In order to avoid this, it is known to mount a freely rotating spindle in a yoke that receives its end, so as to be able to rotate the capture pin and spindle assembly in the event that the capture pin is stuck on the spindle. However, this solution is not satisfactory in operation. In particular, it is difficult for the operator to verify during the inspection operation whether the spindle is blocked or freely rotating. In addition, the free rotation of the spindle makes it difficult to use it as a lubrication channel for the capture pin in practice. Summary of the invention

[0005] The present invention aims to propose a capture pin capable of alleviating the above-mentioned disadvantages.

[0006] In order to achieve this purpose, a capture pin is proposed, which is intended to be installed on a movable element to be hooked by a locking hook in order to fix the movable element in a given position. The capture pin comprises: a main body, which is provided with a longitudinal opening for mounting it on a main shaft; and a rotating outer surface having a central portion, which has a convex profile cooperating with the hook, characterized in that the central portion of the outer surface is formed on a central ring, and the central ring is installed so that it can rotate freely on the central bearing surface of the main body.

[0007] Therefore, even if the body of the capture pin is stuck on the main shaft through which it passes, the central ring can always rotate freely on the body and thus roll on the hook. Therefore, the invention can achieve double rotation without the need for the main shaft to rotate freely.

[0008] Furthermore, checking the free rotation of the body and the center ring is very simple and suitable for regular inspections during pre-flight visits.

[0009] According to a specific aspect of the invention, the outer surface of the capture pin comprises a first side portion and a second side portion, the first side portion being formed on one side of the central ring on a portion integral with the main body, the second side portion being formed on the other side of the central ring on an auxiliary ring mounted so as to rotate freely on an auxiliary bearing surface of the main body.

[0010] If necessary, the central bearing surface and the auxiliary bearing surfaces are formed on the same cylindrical surface.

[0011] According to a first embodiment variant, the first side portion, the central portion and the second side portion of the outer surface provide a non-fractured convex profile without being fractured.

[0012] The so-called "non-break" convex profile refers to a substantially smooth convex profile, ie, a continuous and relatively gradual change without any other profile breaking steps.

[0013] According to a second embodiment variant, the first side and the second side of the outer surface extend along a cylindrical surface.

[0014] According to a particular embodiment of the invention, the body is made of steel and the center ring is made of a material suitable for friction and anti-seizing.

[0015] The invention also relates to an aviation device comprising a fixed element on which a movable element provided with such a capture pin is mounted and a locking hook connected to the fixed element to hook the capture pin and hold the movable element in a given position relative to the fixed element.

[0016] The invention also relates to an undercarriage comprising a movable element provided with such a capture pin.

[0017] The invention also relates to a method for mounting a capture pin according to the invention, comprising mounting the capture pin in a freely rotatable manner on a spindle of a movable element, the spindle being rotationally fixed to the movable element. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention will be better understood from the following description of specific embodiments of the invention given with reference to the figures in the accompanying drawings, in which:

[0019] Figure 1 is a front view of a movable element of a capture pin according to a first specific embodiment of the present invention, during the approach of a hook of a locking box, with one guide of the locking box removed for greater clarity;

[0020] Figure 2 yes Figure 1 A longitudinal cross-sectional view of a capture pin received in a locking box hook, with the clearance exaggerated for greater clarity;

[0021] Figure 3 is similar to Figure 1, but only the capture pin itself is shown;

[0022] Figure 4 is similar to Figure 3 0026] Figure 2 is a view of a variation of an embodiment of a capture pin of the present invention. DETAILED DESCRIPTION

[0023] refer to Figure 1 , Figure 2 and Figure 3 The capture pin 100 of the invention is rotary and comprises a body 101 comprising a cylindrical longitudinal opening 120 to be passed through a spindle 1 mounted on two yokes 2 of a movable element 3, such as in this case an aircraft landing gear. When the movable element 3 reaches the position in which it must be fixed and locked, the capture pin 100 is intended to be hooked by the hook 4 of the locking box 5. To this end, in this case, the locking box 5 comprises guides 6 on either side of the hook 4 to guide the capture pin 100 during parking of the hook 4.

[0024] According to the invention, the body 101 comprises a cylindrical outer surface 102 which defines in turn a central bearing surface 103 and an auxiliary bearing surface 104. The central bearing surface 103 is axially limited by a shoulder 105 formed by the face of a lateral projection 106 of the body 101. On the central bearing surface 103 and the auxiliary bearing surface 104, a central ring 107 and an auxiliary ring 108 are passed and received, which are free to rotate around the same axis of rotation.

[0025] The center ring 107 is intended to be in contact with the hook 4, while the protrusion 106 and the auxiliary ring 108 are intended to be in contact with the guide 6. The center ring 107 can rotate freely on the body 101, so that if it is stuck on the main shaft 1, the center ring 107 can always rotate during contact with the hook 4. Rotational redundancy is thus achieved, which does not require the main shaft 1 to be rotationally mounted in the yoke 2 of the movable element 3, so that the main shaft 1 can be rotationally fixedly mounted in the yoke 2. Similarly, the auxiliary ring 108 is rotatably mounted on the body 101 so that the outer surfaces of the protrusion 106 and the auxiliary ring 108 can rotate relative to each other, which helps the capture pin 100 to roll along the guide 6.

[0026] Furthermore, the operator can easily verify the free rotation of the body on the spindle, as well as the free rotation of the rings on the body. The verification procedure consists in blocking the rotation of the central ring 107 on the one hand and rotating the protrusions 106 and the side rings 108 on the other hand. This procedure enables verification of all the sliding trajectories. Thus, the detection of blockages is significantly facilitated.

[0027] In this case, and according to Figure 3In the first embodiment variant which can be seen in particular in FIG. 1 , the lateral protrusions 106, the central ring 107 and the auxiliary ring 108 have respective outer surfaces 109, 110, 111, each defining a portion (respectively the two side portions constituting the central portion) of the outer surface of the capture pin with a non-interrupted convex profile. In the embodiment shown, the profile is arched, thus with a constant bending radius R, but any other non-interrupted convex profile is also suitable within the scope of the invention.

[0028] according to Figure 4 In the embodiment variant shown, the protrusion 106 and the auxiliary ring 108 have cylindrical outer surfaces, so that only the outer surface of the central ring 107 is curved. This arrangement reduces the risk of degradation of the outer surfaces of the protrusion 106 and the auxiliary ring 108 due to excessive contact pressure against the guide rail 6.

[0029] Embodiments of the capture pin 100 with several parts enable the choice of separate materials for the body and the rings. In particular, it may be chosen to make the body from steel and the center ring from a material suitable for friction and anti-seizure, such as bronze or an iron alloy. Alternatively, a self-lubricating bushing may be inserted between the body and the ring. It is also possible to directly provide the friction surfaces of the spindle 1, the body 101 and the coating rings 107 and 108 to facilitate their sliding.

[0030] If necessary, this several-part embodiment allows replacing only the most commonly used parts while leaving the other parts operational.

[0031] The double rotation initiated according to the invention between the spindle 1 and the body 101 of the capture pin, and between the body 101 of the capture pin and the centering ring 107, makes it possible to use the spindle 1 stopped in rotation on the yoke 2. The fixing of the spindle 1 makes it possible to avoid large movements between the inner diameters of the spindle 1 and the yoke 2, which would lead to a deterioration of the contact surface. It is then possible to drill a lubrication channel 7 into the spindle 1, on the one hand essentially leading to the middle of the body 1 and on the other hand to the end of the spindle 1 provided with a lubricator 8. The fixing of the spindle 1 makes it possible to orient the lubrication hole perpendicular to the load in the neutral plane, thereby increasing the resistance of the component. It is therefore necessary to note that, although the radial section of the lubrication channel 7 has been Figure 2 , but the radial section is actually positioned perpendicular to Figure 2 The protrusion 106 is provided internally with: an annular groove 106.1, in which the radial section of the lubricating channel 7 is open; and an axial groove 106.2 at the closed end, in which radial ducts 106.3, 106.4 are open, both of which pass through the thickness of the protrusion 106 to relatively open to the outer surface of the protrusion 106. The two channels 106.3 are open to the annular groove 107.1 arranged on the inner side of the ring 107, while the duct 106.4 is open to the annular groove 108.1 arranged on the inner side of the ring 108. It can be understood that:

[0032] The radial section of the lubrication channel 7, the annular groove 106.1 and the axial groove 106.2 form means for lubricating the interface between the spindle 1 and the body 101;

[0033] The radial section of the lubrication channel 7, the annular groove 106.1, the axial groove 106.2, the radial duct 106.3 and the annular groove 107.1 form means for lubricating the interface between the projection 106 and the ring 107;

[0034] The radial sections of the lubricating channel 7 , the annular groove 106 . 1 , the axial groove 106 . 2 , the radial ducts 106 . 4 and the annular groove 108 . 1 form means for lubricating the interface between the projection 106 and the ring 108 .

[0035] The invention is not limited to the above description, but on the contrary covers any variant within the ambit defined by the accompanying claims.

[0036] In particular, although the capture pin shown in this case comprises an auxiliary bearing surface extending into the extension of the central bearing surface to receive the auxiliary ring, the auxiliary bearing surface may extend along another cylindrical surface other than the central bearing surface. It is even possible to remove the auxiliary bearing surface and the auxiliary ring by making the auxiliary ring integral with the body or by shrinking, thereby forming the second protrusion. Thus, the central ring will advantageously be divided into two parts so as to be able to be mounted on the central bearing surface between the two protrusions. Of course, the option of relative rotation between the two protrusions is then no longer there.

[0037] Alternatively, the projection may be removed in order to replace it on the body with a second auxiliary bearing surface suitable for receiving a second auxiliary ring, the second auxiliary ring being mounted so as to be able to rotate freely.

[0038] Although the outer surfaces of the two side portions 109, 111 on either side of the central portion 110 have been described as extending from the central portion according to a non-interrupted convex profile, another profile may be provided which varies gradually or not (thus presenting interruptions, such as steps).

[0039] The guide 6 is optional.

[0040] The invention relates to any aviation device comprising a fixed element on which a movable element provided with a capture pin according to the invention is mounted and a locking hook connected to the fixed element to hook the capture pin and hold the movable element in a given position relative to the fixed element.

[0041] The invention is applicable, for example, to aircraft landing gear comprising a movable element provided with such a capture pin. The movable element is, for example, a landing gear box, which is hinged to the aircraft structure and is movable in a manner known per se between output positions of the wheel well, and when the box is in the retracted position, the locking hook hooks the capture pin to hold the box in this position.

[0042] The movable element may also be a wheel bay door or any other movable element of an aircraft. The present invention is also applicable to fields other than vehicles.

Claims

1. An aircraft landing gear, comprising a landing gear (3) provided with a yoke supporting a main shaft, on which a capture pin (100) is mounted which is hooked by a hook (4) of a locking box (5), the locking box (5) being intended to be mounted on a structure of the aircraft in order to fix the landing gear in a given position relative to the structure; the capture pin comprising: A body (101) provided with a longitudinal opening (120) enabling it to be mounted on the spindle (1); and a rotating outer surface having a central portion (110) having a convex profile cooperating with the hook, characterized in that the central portion (110) of the outer surface is formed on a central ring (107) mounted so as to rotate freely on the central bearing surface (103) of the body.

2. The landing gear according to claim 1, characterized in that: The rotating outer surface of the capture pin comprises a first side portion (109) and a second side portion (111) on either side of the central portion (110), the first side portion (109) and the second side portion (111) extending with the central portion according to a non-break convex profile.

3. The landing gear according to claim 2, characterized in that: The non-fractured convex profile has a constant curvature (R).

4. The landing gear according to claim 1, characterized in that: The rotational outer surface of the capture pin comprises a first side portion (109) and a second side portion (111) on either side of the central portion (110), the first side portion (109) and the second side portion (111) extending along a cylindrical surface.

5. The landing gear according to claim 1, characterized in that: The body also supports an auxiliary bearing surface (104) on which an auxiliary ring (108) is received in free rotation, coaxially with the central ring.

6. The landing gear according to claim 5, characterized in that: The central bearing surface (103) and the auxiliary bearing surface (104) are formed on the same cylindrical outer surface (102) of the main body.

7. The landing gear according to claim 1, characterized in that: The body (101) is made of steel, while the center ring is made of a material suitable for friction and anti-seizing.

8. The landing gear according to claim 1, characterized in that: The main shaft is rotationally fixed to the landing gear.

9. The landing gear according to claim 8, characterized in that The main shaft (1) is provided with a lubrication channel (7) opened to the end of the main shaft.

10. Method for controlling a capture pin in a landing gear according to any one of claims 1 to 9, comprising verifying the free rotation of the different components of the capture pin.

11. The method according to claim 10, characterized in that This includes verifying the free rotation of the body on the spindle, and the free rotation of each ring on the body.

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