Torque measuring device for tightening / loosening a nut in a restricted access location and method of using such a torque measuring device
A compact torque wrench with a specialized body structure and triggering mechanism addresses the challenge of applying correct torque in confined spaces, ensuring precise nut tightening and loosening, thus reducing maintenance time and preventing deviations.
Patent Information
- Application Number
- FR2024003110
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2024-03-27
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2044-03-27
AI Technical Summary
Existing tools are too bulky to be used effectively in the confined spaces of aircraft fuel tank hatches, making it difficult to tighten or loosen nuts with the correct torque, leading to potential under-tightening or over-tightening and increased maintenance time.
A compact torque wrench with a unique body structure and triggering mechanism, allowing it to be used in restricted spaces, ensuring the correct torque is applied by transitioning between rest and travel positions based on applied force.
Enables precise tightening and loosening of nuts in confined spaces, preventing under-tightening or over-tightening, reducing maintenance time and preventing deviations from aircraft specifications.
Smart Images
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Abstract
Description
Title of the invention: Torque measuring device for tightening / loosening a nut in a restricted access location and method of using such a torque measuring device. Technical field
[0001] The present application relates to a dynamometric device for tightening / loosening a nut, particularly used in the aeronautical field, in a confined space, as well as to a method of using such a dynamometric device, and in particular a method of tightening a nut by means of said dynamometric device. PREVIOUS STATE OF THE ART
[0002] As is known, some aircraft are equipped with one or more additional fuel tanks. An additional fuel tank is generally arranged under the floor of the aircraft cabin, and a connection between this fuel tank and a fuel distribution line from this fuel tank is accessible through a hatch in the floor of the aircraft cabin.
[0003] Fig. 1 schematically represents such an aircraft cabin floor 10 in which a hatch 12 is arranged for access to an additional fuel tank 14.
[0004] The auxiliary fuel tank 14 is fluidly connected to at least one aircraft engine 16 by at least one fuel circulation line 18. A portion of this line 18 is accessible through the opening of the hatch 12. The auxiliary fuel tank 14 is also fluidly connected to a pressurization pump 20 by at least one air circulation line 22. A portion of this line 22 is accessible through the opening of the hatch 12. During operation, in order to supply the engine 16, the pump 20 pressurizes the fuel in the auxiliary fuel tank 14 by sending an air flow FA into said auxiliary fuel tank 14 via the line 22, and consequently, the auxiliary fuel tank 14 sends a fuel flow Fc into the engine 16 via the line 18.
[0005] Figure 2 shows an enlarged view of the hatch 12 of Figure 1, and Figures 3 and 4 show views of the inside of the hatch 12. Each pipe 18, 22 fluidly connected to the auxiliary fuel tank 14 has a plate 30 at one of its ends, which is fixed to a wall 24 delimiting a part of the auxiliary fuel tank 14 by means of screws 26 and nuts 28. Between the two pipes 18, 22, there is at least one housing 32, which may contain means for managing operating parameters of the auxiliary fuel tank 14. Below said box 32 and said pipes 18, 22 is arranged a recovery panel 34 for possible leaks of liquid from pipes 18, 22, or other elements arranged in hatch 12.
[0006] For information purposes, the dimensions L12,112, H12 of such a hatch 12 are generally between 15cm and 25cm for the width L12 of the hatch 12, between 50cm and 70cm for the length 112 of the hatch 12, and between 30cm and 40cm for the usable height H12 of the hatch 12 (between the opening of the hatch 12 and the recovery panel 34).
[0007] The distance DI between a pipe 18, 22 and the housing 32 is generally less than 5cm, and the distance D2 between a pipe 18, 22 and the recovery panel 34 is generally less than 10cm.
[0008] In order to properly fix the pipes 18, 22 to the wall 34 of the additional fuel tank 14, and in particular the plate 30 of said pipes 18, 22, each nut 28 must be correctly (with the correct torque) tightened on a screw 26. In order to tighten said nuts 28 with a correct tightening torque on each screw 26, a tightening tool must be used.
[0009] However, as shown in Figures 2 to 4, access conditions inside the hatch 12, around the pipes 18, 22, for tightening said nuts 28 are very restricted. Indeed, around each pipe 18, 22, the operator responsible for tightening said nuts 28 has a space of approximately 10 cm to pass the tightening tool, position it correctly on the nut 28, and perform the tightening movement until the correct tightening torque of said nut 28 is reached, which, depending on the required tightening torque, may be difficult or even impossible in this confined space.
[0010] Access to these nuts 28 is only possible for an operator lying on the ground, blind (no vision of the inside of the hatch 12, and therefore of the nuts 28 to be tightened) and only “by touch”, that is to say by progressing by manual exploration.
[0011] Furthermore, the operator must be permanently physically connected to the clamping tool (for example, via a tether) to prevent the clamping tool from falling, which could cause significant production delays while the tool is retrieved from between the auxiliary fuel tanks 14. The presence of this tether complicates the use of the clamping tool, as the tether can become entangled in various places within the access hatch 12 to the auxiliary fuel tank 14.
[0012] Thus, access to said nuts 28 in order to tighten them with the desired tightening torque by equipment currently available on the market is not possible, these tools being bulky and not being able to be used in such a confined space.
[0013] Furthermore, during aircraft maintenance, it may be necessary to check the tightness of said nuts 28, or disassemble / reassemble pipes 18, 22, and therefore loosen / tighten said nuts 28. However, during such a maintenance operation, the floor 10 of the cabin is then fitted with a floor covering and seats, which makes access to the inside of hatch 12 even more difficult.
[0014] It is possible to deviate from the use of a pre-formed tightening tool for tightening said nuts 28 with the predetermined correct tightening torque by applying R-suffix deviations to each aircraft equipped with one or more additional fuel tanks 14 in the configuration described above and shown in [Fig. 1]. A deviation is a non-conformity of a part of an aircraft with respect to the aircraft's originally intended definition. An R-suffix deviation corresponds to a permanent deviation, which relates to a non-conformity of the aircraft that results in limitations in the use of said aircraft (either operational or maintenance-related).
[0015] There is therefore a need for a new clamping tool to ensure proper tightening of the joint between auxiliary fuel tanks on aircraft, which can be used in a confined environment. Summary of the invention
[0016] The present invention aims to provide a nut tightening / loosening device with correct tightening torque which is compact, and which has a shape and dimensions suitable for use of said device in a space with restricted access.
[0017] To this end, the invention relates to a torque device for tightening / loosening at least one nut, comprising a body including: - a first part comprising a socket shaped to fit the profile of the nut to be tightened, the first part extending in a first direction, - a second part having a first end fixed to the first part and a second end, the second part extending in a second direction at an angle between 60° and 95° to the first direction, and - a third part having a first end and a second end connected to the second end of the second part, the third part extending in a third direction at an angle between 60° and 95° with respect to the second direction,
[0018] According to the invention, the body also includes a triggering means arranged at a junction between the second and third parts, the triggering means comprising a spherical bearing having an outer ring integral with the third part and an inner ring mounted with a spherical joint in the ring external and in which is arranged the second end of the second part, the second and third parts being movable relative to each other, at the level of the triggering means, between a first position, called the rest position, in which the inner ring is coaxial with the outer ring when a torque less than a predetermined value is exerted by the sleeve on the nut to be tightened / loosened, and a second position, called the travel position, in which the inner ring is subjected to travel relative to the outer ring, when a torque greater than or equal to the predetermined value is exerted by the sleeve on the nut to be tightened / loosened.
[0019] Advantageously, such a torque device can be used in a confined space. Furthermore, this device ensures that the nut is tightened with the correct torque, thus preventing under-tightening of the nut (and therefore preventing loosening of the nut due to vibrations) or over-tightening of the nut (and therefore weakening of the fastener attached to the nut).
[0020] According to another feature, the first part extends substantially parallel to the third part.
[0021] According to another feature, the first part extends along the first direction over a length between 2cm and 6cm, the second part extends along the second direction over a length between 5cm and 12cm, and the third part extends along the third direction over a length between 10cm and 20cm. These dimensions of the dynamometric device make it possible to guarantee the use of said device in a confined space, and in particular in the confined space as described above.
[0022] According to another feature, the triggering means comprises a spherical bearing including an outer ring integral with the third part and an inner ring mounted with a spherical link in the outer ring, the second end of the second part being inserted into the inner ring.
[0023] According to another feature, the second part is removable relative to the inner ring.
[0024] According to another feature, the spherical bearing comprises rolling elements arranged between the inner ring and the outer ring. In one configuration, the rolling elements are balls. In another configuration, the rolling elements are rollers.
[0025] According to another feature, the third part includes a gripping element which extends from the first end of the third part in the third direction over a length between 40% and 80% of a length of the third part in the third direction.
[0026] According to another feature, the gripping element has a dimension along a radial direction to the third direction of between 1cm and 3cm.
[0027] The invention also relates to a method for tightening at least one nut using a torque device as described above. The method comprises: - a positioning step, during which the socket of the device is positioned on the nut to be tightened, - a tightening step, during which a tightening torque is applied to said nut until the triggering means moves from the first position to the second position, - a tightening stop step, during which the application of tightening torque to the nut is stopped so that the triggering means returns from the second position to the first position, and - a removal step, during which the device's socket is removed from the tightened nut.
[0028] According to another feature, the tightening process includes, before the positioning step, a calibration step, during which the travel of the inner ring of the triggering means relative to the outer ring is calibrated according to the desired tightening torque on the nut to be tightened. Brief description of the drawings
[0029] Other features and advantages will become apparent from the following description of the invention, given by way of example only, with reference to the accompanying drawings, among which:
[0030] [Fig-1] is a schematic top view of an aircraft cabin floor including an access hatch to an additional fuel tank, already presented,
[0031] [Fig.2] is a schematic top view of the access hatch to an additional fuel tank of [Fig.1], already presented,
[0032] [Fig.3] is a schematic side view of the inside of the access hatch to an additional fuel tank of [Fig.1], already presented,
[0033] [Fig.4] is a schematic cross-sectional view of the interior of the access hatch to an additional fuel tank of [Fig.1], already presented,
[0034] [Fig.5] is a schematic top view of an aircraft comprising an additional fuel tank,
[0035] [Fig.6] is a schematic perspective view of a dynamometric device for tightening / loosening a nut according to an embodiment of the invention,
[0036] [Fig.7] is a schematic top view of the dynamometer device of [Fig.6]
[0037] [Fig.8] is a schematic side view of the dynamometer device of [Fig.6],
[0038] [Fig.9] is a schematic side view of a triggering means of the device torque wrench for tightening / loosening a nut, in its rest position, according to one embodiment of the invention,
[0039] [Fig. 10] is a schematic side view of the triggering means of the torque device for tightening / loosening a nut, in the travel position, according to an embodiment of the invention,
[0040] [Fig. 11] represents a flowchart of a method of using a dynamometric device for tightening / loosening a nut in a restricted space, according to an embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION
[0041] Figure 5 represents an aircraft 1 comprising an additional fuel tank 14 intended to supply at least one engine 16 of said aircraft. The additional fuel tank 14 is arranged under the floor of the aircraft cabin, as shown in Figure 1 described above, and is accessible via an access hatch 12, as shown in Figures 2 to 4 described above.
[0042] In order to tighten / loosen the nuts 28 of the plates 30 of the pipes 18, 22, within the limited space provided, a torque wrench 40 is used by an operator. Such a wrench 40 is shown in Figures 6 to 8.
[0043] The device 40 comprises a body 42 consisting of a first part 44, a second part 46 and a third part 48, the second part 46 being arranged between the first and third parts 44, 48.
[0044] The first part 44 of the device 40 comprises a sleeve 50 whose shape is adapted to the profile of the nut 28 to be tightened / loosened. The first part 44 extends overall in a first direction denoted X. Along the first direction X, the length L44 of the first part 44 is generally between 2 cm and 6 cm.
[0045] The second part 46 of the device 40 has first and second ends 52, 54, and is fixed to the first part 44 of the device 40 at its first end 52. The second part 46 extends overall along a second direction denoted Y, which has an angle between 60° and 95° with respect to the first direction X. In one configuration, the second part 46 is substantially perpendicular to the first part 44, that is to say, the second direction Y is oriented at an angle of 90° with respect to the first direction X. Along the second direction Y, the length L46 of the second part 46 is generally between 5 cm and 12 cm.
[0046] The third part 48 of the device 40 has first and second ends 56, 58, and is connected to the second end 54 of the second part 46 of the device 40 at its second end 58. The third part 48 extends globally along a third direction denoted Z, which has an angle between 60° and 95° with respect to to the second direction Y. According to one configuration, the third part 48 is substantially perpendicular to the second part 46, that is, the third direction Z is oriented at an angle of 90° to the second direction Y. According to another configuration, the third part 48 is substantially parallel to the first part 44. By “substantially parallel,” it is understood that the angle between the first direction X and the third direction Z is less than or equal to 5°. Along the third direction Z, the length L48 of the third part 48 is generally between 10 cm and 20 cm.
[0047] The third part 48 includes a gripping element 60, for example a handle, which extends from its first end 56 towards its second end 58, over at least 40% of the length L48 of the third part 48. The gripping element 60 extends over a length L60 equal to a maximum of 80% of the length L48 of the third part 48. Advantageously, this gripping element 60 has a minimum length which is sufficient to allow a correct grip by the operator, but also a maximum length which is as small as possible so that when tightening a nut, i.e. during the angular movement transmitted by the operator to the device 40, the gripping element 60 does not come into contact with an element of its environment (which is a restricted space, as described previously with reference to Figures 1 to 4).Furthermore, the gripping element 60 has a diameter D60 (dimension along a radial direction to the axis extending along the third direction Z) of between 1 cm and 3 cm. Indeed, the gripping element 60, together with the device 40, contributes to the amplitude described by the angular movement of tightening the nut, and the larger the diameter of the handle, the greater the angular movement of the device 40 will be able to come into contact with its environment.
[0048] In one configuration, the third part 48 may also include an attachment point 72 for a connecting element 74, such as a link, which allows the device 40 to be connected to the operator and facilitates the retrieval of said device 40 if the operator inadvertently drops it. In another configuration, the attachment point 72 is optional, the device 40 being more easily handled by an operator than prior art clamping tools, and it is therefore possible to avoid the presence of a connecting element 74 between the device 40 and the operator.
[0049] Of course, the dimensions L44, L46 and L48 mentioned here are given as an indication and are adapted to the case presented in figures 1 to 4, but the device 40 could have smaller or larger dimensions depending on the environment in which the device 40 is intended to be used.
[0050] The body 42 of the device 40 also includes a triggering means 62 arranged at the junction between the second and third parts 46, 48 of the device 40. The triggering means 62 is shown more precisely in Figures 9 and 10.
[0051] The triggering means 62 comprises a spherical bearing 64 having an outer ring 66 integral with the third portion 48 of the device 40, and an inner ring 68 mounted with a spherical joint in the outer ring 66 and into which the second end 54 of the second portion 46 of the device 40 is inserted. In one configuration, the second portion 46 of the device 40 is press-fitted into the inner ring 68 and is therefore removable. In another configuration, the second portion 46 of the device 40 is fixed to the inner ring 68. The inner ring 68 and outer ring 66 are coaxial and centered on an axis corresponding to the third direction Z. Rolling elements 70 are arranged between the inner ring 68 and the outer ring 66, around the central axis of the inner ring 68 and outer ring 66 corresponding to the third direction Z, to enable the spherical joint.The spherical bearing 64 can be a ball or roller spherical bearing, i.e. the rolling elements 70 can be balls or rollers.
[0052] The second and third parts 46, 48 of the device 40 are therefore movable relative to each other at the triggering means 62. Figure 9 shows a first position of the triggering means 62, called the rest position, in which a torque less than a predetermined value is exerted on the second part 46 of the device 40 relative to the third part 48 of the device 40. In this rest position, the inner ring 68 is coaxial with the outer ring 66, and the rolling elements 70 are entirely disposed between the inner ring 68 and the outer ring 66. Figure 10 shows a second position of the triggering means 62, called the travel position, in which a torque greater than or equal to the predetermined value is exerted on the second part 46 of the device 40 relative to the third part 48 of the device 40.In this travel position, the inner ring 68 is subjected to travel relative to the outer ring 66, so that the inner ring 68 is no longer coaxial with the outer ring 66, and part of some rolling elements 70 is disposed outside the space between the inner ring 68 and outer ring 66. The inner ring 68 has a travel angle of between 5° and 15° relative to its central axis, here an axis oriented along the Z direction.
[0053] The triggering means 62 can be a triggering device with a ball / roller disengagement torque limiter.
[0054] The assembly formed by the first and second parts 44, 46 of the device 40 can be removed, in order to adapt the dimensions of the sleeve 50 to the nut 28 to be tightened / loosened. More specifically, the first part 44 comprising the sleeve 50, the first and second parts 44, 46 of the device 40 being fixed to each other, and the second part 46 of the device 40 being inserted into the inner ring 68 of the triggering means 62, in order to change the sleeve 50 to adapt the device 40 to If other nut sizes 28 are incompatible with the socket 50 initially mounted on the device 40, the first and second parts 44 and 46 of the device 40 can be interchanged with other first and second parts of the device 40 whose socket 50 dimensions are better suited to the new nut sizes. This advantageously allows the third part 48 of the device 40 to be reused for tightening / loosening different nut sizes.
[0055] A method for using the dynamometric device 40 by an operator will now be described. The steps of such a method are shown in [Fig. 11].
[0056] For tightening at least one nut 28 using the device 40, the method includes, once the operator is in position (for example, in the confined space as described in relation to Figures 1 to 4), a step E10 of positioning the sleeve 50 of the device 40 on the nut 28 to be tightened. The method then includes a step E20 of tightening said nut 28 until the triggering means 62 moves from the first rest position to the second travel position. The shape and dimensions of the device 40 are optimized so that the operator can make the device 40 perform a complete tightening movement until the desired tightening torque is reached. In other words, the method includes a step of applying a tightening torque to the nut 28 until the torque corresponding to the predetermined value is reached.More specifically, as long as the tightening torque exerted by the operator, via the third part 48 of the device 40, on the sleeve 50 positioned on the nut 28 to be tightened (via the junction between the second and third parts 46, 48 of the device 40 and the fixed connection between the first and second parts 44, 46 of the device 40), remains below the predetermined value, the triggering means 62 remains in its first rest position. When the torque exerted by the operator on the sleeve 50 positioned on the nut 28 to be tightened, via the third part 48 of the device 40, becomes greater than or equal to the predetermined value, the triggering means 62 moves into its second travel position. The movement of the travel means from the first to the second position signifies that the tightening torque of the nut 28 has been reached, and the operator can stop tightening the nut 28.The predetermined torque value is pre-calibrated according to the desired tightening torque on the nut 28 to be tightened. As the socket 50 is positioned on the nut 28 to be tightened, the operator will feel the movement of the assembly composed of the first and second parts 44, 46 of the device 40 relative to the third part 48 of the device 40 that he is holding. Indeed, when the tightening torque is reached, the inner ring 68, which is fixed to the second part 46 of the device 40, is subject to movement relative to the outer ring 68, which is fixed to the third part 48 of the device 40. The process then includes a step E30 of stopping the tightening of the nut 28. Stopping the tightening by the operator will cause a return movement of the un- means. The locking mechanism 62 moves from its second locking position to its first rest position. The process includes a step E40 of removing the sleeve 50 from the device 40 of the tightened nut 28. This process is then repeated for each nut 28 to be tightened.
[0057] The method may include a preliminary step E01 of calibrating the device 40, so as to calibrate the travel of the triggering means 62 according to the desired tightening torque on the nut 28 to be tightened.
[0058] For loosening a nut 28, the device 40 can be recalibrated so that a loosening torque greater than the tightening torque required to trigger the movement of the triggering means 62 is applied. In other words, the predetermined value of the loosening torque to be applied to trigger the movement of the triggering means 62 can be greater than the predetermined value of the tightening torque required to trigger the movement of the triggering means 62. This advantageously eliminates any movement during the loosening of a nut, facilitates the use of the device 40 by the operator, and improves its resistance (the loosening torque being applied to the device 40 with the triggering means in the rest position).
[0059] During an aircraft maintenance operation, the device 40 can be used to control the tightening torque of the nuts 28, and tighten them if their tightening torque is less than the predetermined value.
Claims
Demands
1. A torque device (40) for tightening / untightening at least one nut (28), comprising a body (42) comprising: - a first part (44) comprising a sleeve (50) of a shape adapted to the profile of the nut (28) to be tightened / loosened, the first part (44) extending along a first direction (X), - a second part (46) having a first end (52) fixed to the first part (44) and a second end (54), the second part (46) extending in a second direction (Y) at an angle between 60° and 95° with respect to the first direction (X), and - a third part (48) having a first end (56) and a second end (58) connected to the second end (54) of the second part (46), the third part (48) extending in a third direction (Z) with an angle between 60° and 95° with respect to the second direction (Y),The body (42) also comprising a triggering means (62) being arranged at the junction between the second and third parts (46, 48), the triggering means (62) comprising a spherical bearing (64) having an outer ring (66) integral with the third part (48) and an inner ring (68) mounted with a spherical joint in the outer ring (66) and in which the second end (54) of the second part (46) is arranged, the second and third parts (46, 48) being movable relative to each other, at the level of the triggering means (62), between a first position, called the rest position, in which the inner ring (68) is coaxial with the outer ring (66) when a torque less than a predetermined value is exerted by the sleeve (50) on the nut (28) to be tightened / loosened, and a second position, called the travel position, in which the inner ring (68) is subjected to travel relative to the outer ring (66),when a torque greater than or equal to the predetermined value is exerted by the socket (50) on the nut (28) to be tightened / loosened.
2. A dynamometric device (40) according to the preceding claim, wherein the first part (44) extends substantially parallel to the third part (48).
3. Dynamometric device (40) according to any one of the preceding claims, wherein the first part (44) extends along the first direction (X) over a length (L44) between 2cm and 6cm, the second part (46) extends along the second direction (Y) over a length (L46) between 5cm and 12cm, and the third part (48) extends along the third direction (Z) over a length (L48) between 10cm and 20cm.
4. Dynamometric device (40) according to any one of the preceding claims, wherein the triggering means (62) comprises a spherical bearing (64) including an outer ring (66) integral with the third part (48) and an inner ring (68) mounted with a ball joint in the outer ring (66), the second end (54) of the second part (46) being inserted into the inner ring (68).
5. Dynamometric device (40) according to the preceding claim, wherein the second part (46) is removable relative to the inner ring (68).
6. Dynamometric device according to any one of claims 4 or 5, wherein the spherical bearing (64) comprises rolling elements (70) arranged between the inner ring (68) and the outer ring (66), and wherein the rolling elements (70) are balls or rollers.
7. Dynamometric device according to any one of the preceding claims, wherein the third part (48) comprises a gripping element (60) which extends from the first end (56) of the third part (48) along the third direction (Z) over a length (L60) between 40% and 80% of a length (L48) of the third part (48) along the third direction (Z).
8. Dynamometric device according to the preceding claim, wherein the gripping element (60) has a dimension (D60) along a radial direction to the third direction (Z) between 1cm and 3cm.
9. A method for tightening at least one nut (28) using a torque device (40) according to any one of the preceding claims, comprising: - a positioning step (E10), during which the sleeve (50) of the device (40) is positioned on the nut (28) to be tightened, - a tightening step (E20), during which a tightening torque is applied to said nut (28) until the triggering means (62) moves from the first position to the second position, - a tightening stop step (E30), during which the application of a tightening torque to the nut (28) is stopped so that the triggering means (62) moves from the second position to the first position, - a removal step (E40), during which the sleeve (50) of the device (40) is removed from the tightened nut (28).
10. A clamping method according to the preceding claim, comprising, before the positioning step (E10), a calibration step (E01), during which the travel of the inner ring (68) of the triggering means (62) relative to the outer ring (66) is calibrated according to the desired tightening torque on the nut (28) to be tightened.