HK1190444B - Shut-off device with automatically activatable locking - Google Patents

Description

The present invention relates to a cap-locking device whose screw-down allows automatic locking to prevent spontaneous or untimely unscrewing.

In aeronautics, an aircraft engine requires regular maintenance and very rigorous inspection visits, in order to ensure the engine is perfectly reliable during operation. To control the internal parts as well as their possible wear, holes are provided in the engine cartridge. During maintenance operations, a plug closing the orifice is unscrewed and an endoscope can be inserted for exploring the internal cavities and observing the condition of the engine parts.

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The use of a brake pad, a brake pin or a locking wire is a common method of preventing such damage.

However, the accessibility of the plugs in an engine can be very poor, as tubing and other peripheral organs clutter the space around the crankcase. For example, putting an additional brake or locking part on a plunger requires great dexterity and even luck to avoid losing that part. In some cases, the plunger is only accessible with a long tool, any direct manual access to the plunger is impossible even when the plunger is in place.A system of this type has locking and unlocking means that are automatically activated by the rotation of the cap and its longitudinal progression along the axis of rotation. The locking and unlocking means consist of two crowns (or cups) each with a series of teeth directed axially towards the other cap. The teeth have a pointed (or triangular) profile and interpenetrate each other during the axial progression of the cap. One of the crowns is fixed to the crankcase, in the case of a species mounted forcefully on the latter in a manner that is immobilized in rotation.This known cork requires the attachment of a crown to the cartridge by means of a forceful mounting.

In particular, it is noted that the rotary coupling between one of the crowns and the cap is achieved by conformations of conjugate shapes on the crown and on the central body of the cap. In the case of the device described in this document, the crown has key rings that penetrate axially in relation to the direction of screwing in corresponding grooves conforming to the central body of the cap, these key rings being mobile along this longitudinal axis. Alternatively, similar devices are known in which the crown is coupled on the periphery of the central body by a system of interlocking.

In addition, the cap described in this document has means (helical compression spring pushing the cap cap back towards the cartridge cap, asymmetrical tooth profiles on the caps, etc.) which, although already solving the problem of untimely unscrewing, can still be optimized in their shape and function.

The purpose of the present invention is to propose an optimized variant of the cap as described above, which would respond even more effectively to the need to prevent untimely unscrewing while simplifying the constraints of manufacture and assembly of the cap. The purpose of the invention is therefore also to propose a closing device with a shut-off system, which would prevent untimely unscrewing by vibrations produced by an aircraft engine, which would be directly integrated into the closing device, perfectly compacted, and which would not be a nuisance or a risk to opening and closing maneuvers, even in the case of poor accessibility.

For this purpose, the invention concerns a closing device comprising a stopper intended to be placed on or removed from a threaded opening of a cartridge by screwing and unscrewing, respectively, the stopper comprising a central body carrying a thread, and locking and unlocking devices opposed to the spontaneous unscrewing of the stopper, automatically activated by rotation of the stopper and its corresponding progression in the direction of screwing along a longitudinal axis, the locking and unlocking devices comprising two free-flowing coupling organs, one of which is coupled in rotation with the central body and a second organ is immobile in rotation with respect to the cartridge during screwing,characterised by the cap having a skirt rigidly attached to the centre body with a supporting area capable of directly cooperating with a corresponding supporting area of the second organ, and by the first organ being coupled in rotation with the skirt by means of guides conforming to the periphery of the first organ and extending radially with respect to the longitudinal axis, these guides penetrating into conforming conjoined grooves on the inside of the skirt, which extend along the longitudinal axis in such a way as to allow the first organ to move within the skirt along the longitudinal axis.

The rotary drive (or coupling) means are in the invention located between the first organ and the skirt which is itself rigidly solid with the central body. The perfectly cylindrical profile of the central body allows direct guidance of the means of attachment to this central body. The size of the central body can be increased, including its diameter, while maintaining an identical external encumbrance of the cap.

According to other advantages of the invention, the guiding means consist of at least two angular relief areas at the periphery of the second organ, in particular opposite in diameter, each area being radially bounded by an outer cylindrical profile of a diameter greater than the outer cylindrical surface of the first organ and angularly bounded by longitudinal edges in planes forming an angular sector around the longitudinal axis.

This allows the distribution of the forces to be optimized: during assembly or disassembly, the forces are always perpendicular to a straight line passing through the longitudinal axis of the first organ. The forces are thus applied perfectly tangentially, without any radial component (i.e. projected on a radial axis relative to the longitudinal axis). This allows to avoid or limit the phenomena of crushing even blocking of the first organ during the assembly or disassembly phases. These phenomena are also likely to be amplified by an increase in the coefficient of friction of the materials due to a pollution and/or corrosion generated after high operating cycles.

According to further advantages of the invention, the angular sector has an angle of 10 to 45°, including 30°.

According to other advantages of the invention, the radial height of the relief in relation to the longitudinal axis is greater than 1 mm, and is in particular between 1 and 5 mm.

According to other advantages of the invention, the first organ is mobile relative to the central body along the longitudinal axis, between the second organ and an inner skirt bottom, the first organ being pushed back towards the second organ by elastic means of restraint housed in the skirt.

According to other advantageous features of the invention, the central body has an axial stop against which the second organ is pushed in under the pressure of the first organ pushed back by the elastic restraint.

According to other advantages of the invention, the axial stop consists of a machine collar on the central body.

According to other advantages of the invention, the elastic booster means consist of a flat-wire corrugated compression spring.

According to other advantages of the invention, the first and second organs have general ring shapes, the second organ also comprising a protuberance radially extending from the longitudinal axis, this protuberance carrying a restraint rod directed parallel to the longitudinal axis, intended to penetrate a corresponding conformal restraint hole in the cartridge.

According to other advantageous features of the invention, the first and second organs have respective dentures designed to interpenetrate each other during screwing/un screwing.

According to other advantages of the invention, dentures have teeth with a symmetrical profile, the side faces of which are inclined notably at 30° / 30°.

According to other advantages of the invention, dentures have an asymmetrical profile, the side faces of which are oriented in particular at 30° / 60°.

According to other advantages of the invention, in a first embodiment the central body has a rotating grip configuration for rotating drive by means of a screwing/un screwing tool.

According to other advantages of the invention, the skirt has a rotating cap configuration for rotating drive by means of a screwing/un screwing tool. This solution has the advantage of enabling the realization of a more compact closing device. This solution also has the advantage of enabling a larger rotating cap configuration for the same cork volume, and thus also enabling the realization of smaller caps with the same rotating cap configuration.

According to other features of the invention, when the skirt has a rotating grip conformation, the skirt is extended on the side opposite the thread beyond the centre body and defines the grip conformation inside it beyond the centre body.

Further particularities and advantages of the invention will be shown by the following description of non-limiting examples of the invention and in the light of the attached drawings on which: Figure 1 is a cut-out view of a first embodiment of a shutter according to the invention; Figure 2 is a cut-out view of the device according to the cut-out line D-D of Figure 1; Figure 3 is a magnified view of an embodiment detail E of the shutter according to the invention as illustrated in Figure 4; Figure 4 is an external view of the shutter according to the invention as shown in view F of Figure 1; and Figure 5 is a cut-out view of a second embodiment of a shutter according to the invention.

Since these embodiments are by no means limiting, it may be possible to imagine variants of the invention comprising only a selection of features described below, isolated from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the state of the art.

The first method of carrying out the invention is described in Figures 1 to 4.

Depending on the invention, the closing device has a plug 1 intended to be placed on a threaded hole 2 of a cartridge 3, or to be removed from it, respectively by screwing and unscrewing. For example, the threaded hole 2 is formed in a filling of the cartridge 3 of an engine. The threads are standard and in particular do not include any interruptions of the axial groove or flat type. The plug 1 consists of a central body 4 having the general shape of an axis provided with a thread 5 at one end, and at the opposite end of a rotary grip 6 for the rotary drive of the central body 4 using a screw/unscrew tool (not shown).In the illustrated example, the rotary socket conformation is a 4-sided female part intended to receive a 4-sided male screwdriver. Alternatively and in a non-represented manner, the rotary socket conformation may be a 6-sided female part intended to receive a 6-sided male screwdriver. A predetermined clamping torque may be provided by the use of a dynamometric key. In an unillustrated variant, this part may be provided to be replaced by a male conformation on the outside of the central body 1.

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In particular, locking and unlocking are provided by means of locking and unlocking, in particular by loosely coupled devices comprising a first device 7 rotating with the centre body 4 of the stopper 1 and a second device 8 capable of being held in rotation with respect to the crankcase 3 when the centre body 4 is screwed into the 2 hole of the crankcase 3.

The first and second organs 7, 8 each have a dented profile pointing towards the opposite organ. The teeth are precisely conformed on the respective annular faces of the first 7 and second 8 organs vis-à-vis each other. To prevent parasitic loosening by vibration and allow the operator to voluntarily loosen the cap, the dented profile of the first organ 7 is applied by a spring 9 against the identical dented profile of the second organ 8.

In addition, the operator can feel the device clicking when it is being assembled or disassembled and can therefore be assured that the locking system is working properly.

Remarkably, the first and second organs 7, 8 are both embedded in the plug and inseparable from it.

The cap 1 has a cylindrical protective skirt 10 rigidly attached to the center body 4. This skirt 10 is typically rigidly mounted/sewn on the center body 4 by its end having the rotational grip conformation 6, up to a conformal positioning and locking shoulder 11 on the outer periphery of the center body 4. The term rigidly attached means a perfect fit of the skirt on the center body, without any degree of freedom. In a variant embodiment not illustrated of the invention, the skirt may also be welded on the center body.

The skirt has a support zone 12 capable of directly cooperating in support with a support zone 13 corresponding to the second organ 8. The first organ 7 is coupled in rotation with the skirt 10 via guidance means 14, 15 conforming to the periphery of the first organ 7 that extend radially relative to the X longitudinal axis. These guidance means 14, 15 enter into 16 conjoined-shaped grooves conforming to the inside of the skirt 10. The grooves 16 extend along the X longitudinal axis so as to allow the first organ 7 to move within the skirt, following the X longitudinal axis. Consequently, the next first organ 7 is also referred to as the piece or the ring due to degrees of freedom of movement of the X axis.

The guides 14, 15 shall consist of at least two angular relief sections at the periphery of the first organ 7, each of which is radially delimited by an outer cylindrical profile of a diameter greater than the outer cylindrical surface of the first organ 7, and angularly by longitudinal edges in planes forming an angular sector around the longitudinal axis X. This angular sector delimiting the guides shall have an angle α typically between 10 and 45°, e.g. 30° as shown in Figure 2.The forces transmitted from the skirt 10 to these guides 14, 15 (acting on the central axis 4 when screwing or unscrewing) are very advantageously directed along tangents to the first organ 7, so that no radial component is induced during screwing/unscrewing. In the example shown in Figure 2 two diametrically opposite guides are provided. In this case, a typical 90° angle β is observed between the longitudinal edges either directly applied to the screwing or unscrewing.more than two means of guidance may be provided, e.g. three means of guidance angularly distributed around the longitudinal X-axis.

According to the invention, the first organ 7 is mobile in translation with respect to the central body 4 between the second organ 8 and an inner skirt bottom 10, the first organ 7 being pushed back towards the second organ 8, towards the opening of the skirt 10, opposite the inner bottom, under the influence of a spring 9 located around the central body 4. The central body 4 has an axial stop 18 against the second organ 8 cooperates in a butte under the pressure of the first organ pushed back by the spring 9. In the example, this axial stop 18 consists of a collarette machined around the periphery of the central body against 4, on which an inner shoulder of the second organ 8 is supported. In an unillustrated variant, it can be envisaged that the collarette is replaced by an elastic ring.

The second organ 8 is free to rotate relative to the central body 4. It is however immobilizable in rotation relative to the carter 3 when screwed. The second organ 8 has a general ring shape. It has a protuberance 19 radially extending relative to the longitudinal X-axis. This protuberance 19 carries an immobilizer ergot 20 directed parallel to the longitudinal X-axis. The ergot 20 is intended to penetrate a corresponding immobilizer orifice 21 conforming to the carter 3.

When the central body 4 is screwed into threaded orifice 2, the second organ 8 first follows the rotational motion of the stopper 1. When the screw has reached a certain stage, the ergot comes into contact with the outer surface of the carter 3, while rotating, until it reaches the right of the immobilization orifice 21. Any further progression of the stopper along the longitudinal X-axis during screwing causes a corresponding advance of the ergot into the locking orifice, until the second organ 8 meets the outer surface of the carter 3. A further progression of the central body 4 to the carter along the longitudinal X-axis during screwing causes the respective dentures of the first and second organs 8 to intermittently interpenetrate.The group of teeth (or denture) of the first organ 7 is driven in rotation with the cork while the group of teeth (or denture) of the second organ 8 is at this stage immobilized in rotation with respect to the carter 3. During the relative rotation between the two groups of teeth, the latter are alternately in an interpenetration configuration and a tip-on-tip configuration, the transition from one configuration to the other being achieved by relative sliding of the respective adjacent faces of the two groups of teeth.Each translation is performed on a stroke corresponding to the height of the teeth, distance separating the tip of a tooth from the hollow between two teeth, in projection along the longitudinal X-axis. It should be noted that the teeth have preferably a symmetrical profile, i.e. identical inclinations of the sliding surfaces acting on tightening or loosening, in order to optimize the life of the system and control the coefficients of friction.In another not shown embodiment, dentures may have an asymmetrical profile, in particular to provide a greater coefficient of friction in one direction than in the other.

The spring 9 is preferably a flat-wire corrugated compression spring, which has a very small footprint and significantly lighten the cap compared with a similar cap with a helical compression spring.

The cap is assembled as follows: the elements are placed on the central body by its rear end, located on the side of the rotation footprint or shape 6. The second organ 8 is placed first around the central body 4. The first organ 7 is then placed around the central body 4 and stacked on the second organ 8, denture against denture. The spring 9 is then placed around the central body and applied against the first organ 7. The protective skirt 10 is then securely fixed or tightened around the central body and these elements 8.7, 9. The skirt 10 provides protection by simultaneously providing the outer shell of the cap and the rotary coupling (or drive) between the central body 4 and the first organ 7. It is noted that the first organ and the second organ have very compact external shapes, in particular following the direction of the longitudinal X-axis. Their thickness in this direction may be less than 10-15 mm. For example, the first organ may be between 5 and 10 mm thick. These examples are by no means limiting.The Commission has already taken a number of steps to ensure that the information provided by the Member States is adequate.

A second embodiment of the invention will now be described, with reference to Figure 5, but only in so far as it differs from the first embodiment described above.

The skirt 10 has a rotating grip configuration 6 for rotational drive using a screwing/un screwing tool. The shape 6 is formed in the centre of the skirt 10 along the longitudinal (X) axis of the skirt. In the illustrated example, the rotating grip configuration is a female 4-piece part intended to receive a male screwing and un screwing key corresponding to 4.

In the example shown, on the side opposite the central body thread 4, the skirt is extended beyond the end of the central body 4. The part of the skirt that thus extends beyond the central body 4 has a radially non-circular inner wall that defines the rotating socket conformation 6.

This skirt 10 is typically rigidly mounted/sewn on the center body 4 by the longitudinal end of the skirt 10 corresponding to the bottom of the rotating grip conformation 6, up to a conformal positioning and locking shoulder 11 on the outer periphery of the center body 4. Typically the positioning and locking shoulder 11 has a geometric shape, notably a noticeably square one as depicted in the example in Figure 5, which fits tightly on a corresponding profile of the center body 4.

The invention is not limited to the methods described above and includes all technical equivalents of the means presented.

In particular, it was stated earlier that the invention relates to a closing device incorporating an endoscope cap, as this device is intended to close a suitable opening through which access can be obtained to the inside of the cartridge. The device of the invention relates more generally to any closing device incorporating a cap as described above, whether or not such a cap has other characteristics or functions. For example, such a closing device according to the invention may itself be a thermal sensor, a vibration sensor, a particle detector chip or any other means of detection.

In addition, the skirt 10 as described above is for example rigid, i.e. unchangeable in compression along the longitudinal screw axis. The rigid skirt forms a gap supporting the support zone 13 of the second organ 8. In another embodiment of the invention, the skirt can be elastic, i.e. conformed in its structure so that it is deformable at least in compression along the longitudinal screw axis. To this end, it may have protruding, split, or pleated areas allowing its deformation and return to its original shape after deformation of the compression efforts. Such a rigid skirt optimizes the safety of the system by increasing the elastic reserve.

In addition, the groove of the first organ 7 inside the skirt 10 can be adjusted as needed.

Claims (15)

1. Sealing device comprising a plug (1) intended to be placed in a threaded hole (2) in a case (3), or removed therefrom, respectively by screwing and unscrewing, the plug comprising a central body (4) provided with a screw thread (5), and locking and unlocking means opposing the spontaneous unscrewing of the plug, activated automatically by the rotation of the plug (1) and its corresponding movement in the direction of screwing along a longitudinal axis (X), the locking and unlocking means comprising two releasable coupling components (7, 8), a first component (7) of which is coupled in rotation with the central body (4) and a second component (8) of which can be immobilized in rotation with respect to the case (3) during screwing, characterized in that the plug (1) comprises a skirt (10) rigidly connected to the central body (4) and having a bearing zone (12) capable of cooperating directly with a corresponding bearing zone (13) of the second component (8), and in that the first component (7) is coupled in rotation with the skirt (10) via guide means (14, 15) configured on the periphery of the first component (7) and extending radially with respect to the longitudinal axis (X), said guide means (14, 15) entering mutually corresponding grooves (16) configured inside the skirt (10), which extend along the longitudinal axis (X) so as to allow the displacement of the first component (7) inside the skirt (10), along the longitudinal axis (X).
2. Sealing device according to claim 1, characterized in that the guide means (14, 15) are constituted by at least two protrusions angularly distributed on the periphery of the first component, about the longitudinal axis (X), in particular in a diametrically opposed manner, each protrusion being delimited, on the one hand radially by a cylindrical outer profile having a diameter greater than the outer cylindrical surface of the first component (7), and on the other hand angularly by longitudinal edges inscribed within planes forming an angular sector about the longitudinal axis (X).
3. Sealing device according to claim 2, characterized in that the angular sector has an angle comprised between 10 and 45°, particularly 30°.
4. Sealing device according to claim 2 or 3, characterized in that the radial height of the protrusions with respect to the longitudinal axis (X) is greater than 1 mm, and is in particular comprised between 1 and 5 mm.
5. Sealing device according to any one of claims 2 to 4, characterized in that the first component (7) is movable with respect to the central body (4) along the longitudinal axis (X), between the second component (8) and an inner base of the skirt (10), the first component (7) being urged towards the second component (8) by resilient return means (9) housed in the skirt (10).
6. Sealing device according to claim 5, characterized in that the central body (4) comprises an axial stop (18) against which the second component (8) abuts under the force of the first component (7) urged by the resilient return means (9).
7. Sealing device according to claim 6, characterized in that the axial stop (18) is constituted by a collar machined on the central body (4).
8. Sealing device according to any one of claims 5 to 7, characterized in that the resilient return means (9) are constituted by a flat wire wave compression spring.
9. Sealing device according to any one of claims 1 to 8, characterized in that the first component (7) and the second component (8) have generally annular shapes, the second component (8) also comprising a projection (19) extending radially with respect to the longitudinal axis (X), said projection carrying an immobilization lug (20) directed parallel to the longitudinal axis (X), intended to enter a corresponding immobilization hole (21) configured in the case (3).
10. Sealing device according to any one of claims 1 to 9, characterized in that the first component (7) and the second component (8) comprise respective sets of teeth intended to mesh together during screwing/unscrewing.
11. Sealing device according to claim 10, characterized in that the sets of teeth have teeth with a symmetrical profile, the lateral faces of which are inclined particularly at 30°/30°.
12. Sealing device according to claim 10, characterized in that the sets of teeth have teeth with an asymmetrical profile, the lateral faces of which are inclined particularly at 30°/60°.
13. Sealing device according to any one of claims 1 to 12, characterized in that the central body (4) comprises a rotary drive configuration (6) for driving in rotation using a tool for screwing/unscrewing.
14. Sealing device according to any one of claims 1 to 12, characterized in that the skirt (10) comprises a rotary drive configuration (6) for driving in rotation using a tool for screwing/unscrewing.
15. Sealing device according to claim 14, characterized in that the skirt is extended beyond the central body on the side remote from the screw thread and defines the drive configuration inside the skirt beyond the central body.