Fastener selection device for aeronautical assembly

Abstract

A rivet length selection device (1) comprising: a frame (2), a length gauge (5) of a hole passing through an assembly of at least two parts and opening onto opposite faces of said assembly to receive a rivet for securing the two parts, the gauge having a rod (6) mounted to slide on the frame and having a hooked end (7) projecting from a bearing face (4) of the frame so that the hooked end and the bearing face can bear against the opposite faces of the assembly when the rod extends into the hole, a transducer (14) mounted on the frame and arranged to transform the sliding of the rod into an electrical signal representing a sliding amplitude, an electronic circuit (15) connected to the transducer and arranged to convert the electrical signal into a value expressed in a unit of rivet length. FIGURE IN ABRIDGED DIAGRAM: Fig. 1

Description

Title of the invention: Device for selecting a fastener for aeronautical assembly

[0001] The present invention relates to the field of assembly fasteners and the field of measuring tools.

[0002] BACKGROUND OF THE INVENTION

[0003] Assemblies comprising two parts having superimposed portions pierced with through holes provided with rivets are known. Each rivet comprises a body having an end provided with a head bearing against a first external surface of the assembly and a free end which extends projecting from an opposite face of the assembly and which is plastically deformed to bear against said opposite face in such a way that the superimposed portions are clamped between the head and the plastically deformed end of the rivets.

[0004] Riveting is a robust and permanent fastening method. Therefore, riveting appears as a preferred assembly method in the assembly of aeronautical structures.

[0005] The quality of the fastening provided by the rivet depends, however, on the length of the rivet body, which must be adapted to the length of the hole. The length of the through hole is generally measured using a measuring tool comprising a ruler that is inserted into the through hole and is graduated in rivet length units so that the user, by reading the graduation corresponding to the hole length, directly obtains the length of rivet to be used.

[0006] Reading conditions (lighting, position...) and the user's physical condition (fatigue, poor eyesight, inattention) can lead to poor reading, the consequences of which can be catastrophic (rivet failure and jeopardizing the integrity of the assembly).

[0007] Furthermore, there are several types of rivets, and the required rivet length depends on the rivet type. Therefore, there is a specific measuring tool for each rivet type. Consequently, there is a risk that the user may make a mistake when selecting the measuring tool. If the user notices an error in the length of one of the installed rivets, they must remove it, resulting in a loss of time and a risk of damage to one or both parts. Removing this rivet can also introduce an unwanted foreign body (FOD) into the through hole. These errors necessitate several analyses of the parts, causing disruption or even a production stoppage. Moreover, purchasing all the specific measuring tools for a particular type of fastener represents a significant cost.

[0008] SUBJECT OF THE INVENTION

[0009] The invention is intended in particular to remedy at least in part the aforementioned disadvantages. Summary of the invention

[0010] For this purpose, according to the invention, a rivet length selection device is provided, comprising: - a frame, - a length gauge of a hole passing through an assembly of at least two parts and opening onto opposite faces of said assembly to receive a rivet for holding the two parts together, the gauge having a rod mounted to slide on the frame and having a hooked end extending outward from a bearing face of the frame so that the hooked end and the bearing face can bear against the opposite faces of the assembly when the rod extends into the hole, - a transducer mounted on the frame and arranged to transform the sliding of the rod into an electrical signal representative of a sliding amplitude, - an electronic circuit connected to the transducer and arranged to convert the electrical signal into a value expressed in at least one unit of rivet length and present it on a display.

[0011] Thus, a new rivet length selection device is advantageously proposed. The length gauge rod is inserted from one face of the assembly into the through hole to hook the opposite face of the assembly by sliding it relative to the frame resting on the first face of the assembly. The transducer measures the amplitude of the displacement and therefore the length of the through hole, which the electronic circuit converts into the expected rivet length. However, the rivet length is expressed in a specific unit of length. The electronic circuit therefore converts the length measured by the transducer into a value expressed in at least one rivet length unit, and this value is displayed on a screen. This is much simpler for the user than determining the value on the graduation system of a dedicated measuring tool.Therefore, user reading errors are avoided. Furthermore, the selection device can be configured to replace a wide range of measuring tools. Consequently, the choice of measuring tool can no longer be a source of error for the user. Eliminating these sources of error improves the quality of assemblies and provides peace of mind for the user, saves time, and reduces maintenance costs. production. The use of an electronic circuit can also ensure traceability of the values ​​expressed.

[0012] According to optional features, used individually or in whole or in combination: - the electronic circuit includes a table relating hole lengths to values ​​expressed as a plurality of rivet length units corresponding to a plurality of predetermined rivet types; - the device includes a housing arranged on the frame, the housing containing the transducer, at least part of the electronic circuit and the display which is arranged to display the value expressed in rivet length units; - the electronic circuit includes a measurement circuit arranged in the housing and a processing circuit which is remote from the housing, the measurement circuit being connected to the transducer; - the processing circuit is arranged in a computer terminal programmed to communicate with the measurement circuit of the box via a transmitter connected to the measurement circuit and a receiver connected to the processing circuit; - the electronic circuit includes an integrated processing circuit which is arranged to provide the value expressed in rivet length units and which is connected to the display in the case, the electronic circuit being entirely arranged in the case; - the processing circuit includes a rivet type selection menu and an interface arranged to allow a user to make a choice from the selection menu; - the device is incorporated into a caliper comprising at least one first set of jaws for measuring an internal diameter; - the caliper has at least one second set of jaws for measuring an external diameter; - Each set of jaws includes a movable jaw fixed in translation to the rod of the length gauge so that the transducer serves to measure diameter and length.

[0013] Other features and advantages of the invention will become apparent from the following description of particular, non-limiting embodiments of the invention. Brief description of the drawings

[0014] Reference will be made to the attached drawings, among which:

[0015] [Fig-1] [Fig.1] is a schematic elevation view of a selection device of a rivet, according to the invention, during use;

[0016] [Fig.2] [Fig.2] is a perspective view of the selection device illustrated in the [Fig.l];

[0017] [Fig.3] [Fig.3] represents a diagram of a case and a computer terminal of the selection device illustrated in [Fig.2];

[0018] [Fig.4] [Fig.4] is a schematic front view of an alternative embodiment of the selection device according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] With reference to [Fig. 1], the invention relates to the assembly of at least one first part PI and a second part P2 which are joined together. The parts PI and P2 are drilled with a through hole T opening onto opposite faces Fl, F2 of said assembly to receive a rivet for holding the two parts PI and P2 together.

[0020] In particular, the invention relates to a device for selecting 1 a rivet length.

[0021] With further reference to [Fig. 2], the selection device 1 comprises a frame 2 extending longitudinally along a first axis X. The frame 2 is, in this case, shaped as a rectangular parallelepiped whose thickness is negligible compared to the other two dimensions. The frame 2 could have any other shape suitable for its function.

[0022] The frame 2 comprises a first end 3 and a second end 4, opposite the first end 3. The second end 4 comprises an edge wider than that of the first end 3.

[0023] The selection device 1 also includes a gauge of length 5. The gauge of length 5 extends along the first axis X. The gauge of length 5 includes a rod 6, extended by a hooked end 7, projecting from a first bearing face integral with the frame 2. More precisely, the rod 6 projects from the second end 4 forming the first bearing face integral with the frame 2. The hooked end 7 of the gauge includes a face forming a second bearing face 8. The second bearing face 8 forms a right angle with the rod 6. The second bearing face 8 is located opposite the frame 2. More precisely, the second bearing face 8 is located opposite the second end 4 forming the first bearing face integral with the frame 2.

[0024] The rod 6 is mounted to move in translation within the frame 2 to slide according to the needs of a user and includes a lug or slider not visible in the figures allowing the user to slide the rod 6 relative to the frame 2. The rod 6 therefore extends between a service position in which the rod 6 is extended to the maximum outside of the frame 2 and a rest position in which the rod 6 is housed to the maximum inside of the frame 2.

[0025] The selection device 1 also includes a housing 9. In the present case, the housing 9 is fixedly mounted on the frame 2. The housing 9 is shaped like a parallelepiped and extends in length along the first axis X and in width along a second axis Y, the second axis Y being perpendicular to the first X. Of course, the housing 9 could have any other shape suitable for its function.

[0026] The housing 9 includes a first side panel on which is arranged at least one knob 10 which, if necessary, allows the rod 6 to be locked in position relative to the frame 2. The housing 9 includes a second side panel, opposite the first side panel, on which are arranged at least one push button and preferably at least two push buttons. In the present case, the housing 9 includes a first push button 11 and a second push button 12.

[0027] The housing 9 also includes a display 13 arranged on an upper face of said housing 9, the upper face being perpendicular to the first and second lateral sides. The display 13 is, for example, a liquid crystal display (LCD).

[0028] With reference to [Fig. 3], the housing 9 also includes a transducer 14, arranged inside said housing 9. The transducer 14 is therefore mounted on the frame 2. In this case, the transducer 14 is an active electromechanical transducer. Indeed, the transducer 14 is arranged to transform the sliding motion of the rod 6 into an electrical signal representing a sliding amplitude. By way of example, the rod 6 may include an optical coding pattern extending over at least part of the length of the rod 6, and the transducer 14 may include an optronic reader capable of reading the portion of the optical coding pattern facing it in order to deduce a position of the rod 6 relative to the frame 2.Alternatively, the rod 6 may include a magnetic pattern extending over at least part of the length of the rod 6 and the transducer 14 may include a magnetic reader capable of detecting the magnetic field of the magnetic pattern in front of it in order to deduce a position of the rod 6 relative to the frame 2.

[0029] The housing 9 contains an electronic circuit 15.

[0030] The electronic circuit 15 includes a measurement circuit 16 and a processing circuit 17 integrated into the housing 9.

[0031] The electronic circuit 15 includes at least one processing component 18 (electronic and / or software), which is for example a "general purpose" processor, a processor specializing in signal processing (or DSP, for Digital Signal Processor), a microcontroller, or a programmable logic circuit such as an FPGA (for Field Programmable Gate Arrays) or an ASIC (for Application Specified Integrated Circuit).

[0032] The measuring circuit 16 is electrically connected to the transducer 14. The measuring circuit 16 then receives the electrical signal representing a sliding amplitude and converts it into a value expressed in a specific unit of length. The term "specific" will be defined later.

[0033] The electronic circuit 15 also includes a power supply system 19 arranged to electrically supply all the components of the housing 9 that require it. The power supply system 19 is, for example, a battery.

[0034] The display 13 is electrically connected to the electronic circuit 15.

[0035] Furthermore, the first push button 11 is electrically connected to the electronic circuit 15 and allows, by a long press, the electronic circuit 15 and the display 13 to be switched on or off and, by a short press, the measurement circuit 16 to be reset. Switching off the electronic circuit 15 also resets said measurement circuit 16. On the other hand, the second push button 12 is also electrically connected to the electronic circuit 15 and allows a measurement to be acquired.

[0036] The processing circuit 17 further includes a transmitter 20 for communicating with a receiver 21 arranged in a computer terminal 22. The computer terminal 22 includes a human-machine interface. Moreover, the computer terminal 22 includes at least one processing component (electronic and / or software), not shown, which is, for example, a general-purpose processor, a processor specialized in signal processing (or DSP, for Digital Signal Processor), a microcontroller, or a programmable logic circuit such as an FPGA (for Field Programmable Gate Array) or an ASIC (for Application-Specific Integrated Circuit). The computer terminal 22 also includes one or more memories (and in particular one or more non-volatile memories), not shown, connected to or integrated into the processing component.At least one of these memories forms a computer-readable recording medium on which is recorded at least one computer program comprising instructions that lead the processing component to execute at least some of the steps of the selection process that will be described below.

[0037] Communication between the transmitter 20 and the receiver 21 is carried out, for example, via the telecommunications standard called "Wifi" or "Bluetooth".

[0038] The operating principle of the invention will now be described.

[0039] As previously stated, the through hole T is intended to receive a rivet to hold the two parts PI and P2 together. Since there are several types of rivets, the user must choose both the correct type of rivet and the correct rivet length.

[0040] The user powers on the electronic circuit 15 by pressing the first push button 11. Via the terminal's human-machine interface In the computer system 22, the user selects the desired rivet type from a rivet type selection menu. The selected rivet type is then transmitted from the receiver 21 to the transmitter 20 of the processing circuit 17, which then selects the corresponding rivet length unit. The rivet type could also be selected directly using a third button on the housing 9, and the selected rivet would be displayed on the display 13.

[0041] The rivet length unit is, as previously described, a special unit of length. By special, it is meant that the unit of length is a rivet length unit expressed as a dash. The dash is an imperial unit of fractions of an inch. Rivet diameters are generally measured in increments of i inches, and their lengths are generally measured in increments of inches, expressed as a dash at the end of the rivet identification number.

[0042] As is known per se, the diameter of the chosen rivet should ideally be 4 to 6 thousandths of an inch smaller than the diameter of the through hole T. The choice of rivet diameter is made in a conventional manner.

[0043] With reference to [Fig. 1], the user grasps the selection device 1 and inserts the hooked end 7 of the rod 6 of the gauge of length 5 into the through hole T. The user then slides the rod 6 until the bearing face 8 of the hooked end 7 bears against the face F2 of the second part P2 to be assembled. The second end 4 of the frame 2, forming the first bearing face, is, in turn, brought to rest against the face F1 of the first part P1 to be assembled.

[0044] The sliding amplitude of the rod 6 is recovered by the transducer 14 which generates an electrical signal representative of a sliding amplitude.

[0045] When the user determines that the selection device 1 is correctly pressed against faces Fl, F2, they press the second push button 12 to initiate the measurement acquisition. The electrical signal transmitted to the measuring circuit 16 is then converted by the processing component 18 into a length expressed in dashes. To do this, the processing circuit 17 uses a memory containing a table relating hole lengths to values ​​expressed as a plurality of rivet length units corresponding to a plurality of predetermined rivet types. The length in dashes is displayed on the display 13 of the housing 9. Simultaneously, the transmitter 20 transmits the rivet length expressed in dashes to the receiver 21, which transmits this value to the memory of the computer terminal 22. This allows the values ​​transmitted by the electronic circuit 15 to be recorded, thus ensuring traceability of the installed fasteners.To perform a new measurement, the user briefly presses the first push button 11 to reset the measurement circuit. 16. At the end of the measurements, the user presses and holds the first push button 11 to cut off the power supply to the electronic circuit 15.

[0046] The method for selecting a rivet length thus comprises the following steps: - insert the hooked end 7 into the hole T and slide the rod 6 relative to the frame 2 so as to bring the hooked end 7 and the bearing face 4 into contact with the opposite faces F2, Fl of the assembly, - read the value expressed in "dash" format. - place the corresponding rivet in the T hole.

[0047] In the variant of [Fig.4], the selection device 1 is integrated into a caliper 100. Calipers are known to have a depth gauge: the caliper 100 is a caliper of this type but in which the depth gauge has been replaced by the length gauge 5.

[0048] The caliper 100 thus comprises a first set of jaws 101 arranged, in a conventional manner, for measuring an internal diameter such as the internal diameter of the through hole T intended to receive the body of a rivet and a second set of jaws 102 arranged, in a conventional manner, for measuring an external diameter such as the external diameter of the body of a rivet.

[0049] Each set of jaws includes a movable jaw fixed in translation to the rod 6 of the gauge of length 5 so that the transducer 14 serves to measure external diameter, internal diameter and length.

[0050] The caliper frame 100 carries the housing 9, which, as before, contains the electronic circuit 15. The electronic circuit 15 is arranged to allow selection of the type of measurement to be performed and may include an additional button to make this selection: - external diameter measurement, - measurement of internal diameter, - length measurement.

[0051] The operation of the caliper used to measure the length of a through hole is identical to that mentioned previously. It should be noted that it is still possible to use the length gauge 5 to measure the length of a blind hole by placing the hooked end 7 against the bottom of the blind hole.

[0052] The operation of the caliper used to measure the external and internal diameters is identical to the conventional operation of a caliper. The electronic circuit 15 can, however, be arranged to automatically convert the measured diameter into a value in one unit of rivet diameter, such as a dash value.

[0053] It is understood that the caliper then makes it possible to select the diameter of the rivet suitable for the through hole or to determine the dimensions of a rivet which would be without marking.

[0054] The electronic circuit 15 can also be arranged to allow conventional use of the caliper by providing a selection menu allowing the display of measurements to be chosen in a conventional unit of lengths such as millimeters.

[0055] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0056] In particular, the structure may differ from that described. For example, an elastic return means (not shown) may extend between the frame and the rod to apply a restoring force on the rod so that it returns to its rest position.

[0057] In particular, although here the display is an LCD screen, consideration may be given to implementing an E-paper screen or a screen with a twisted or twisted nematic effect, better known by the English name of "Twisted Nematics" (TN) screen.

[0058] Although communication between the transmitter and the receiver is carried out by Wifi or Bluetooth communication module, it may be possible to implement a module conforming to another standard such as an Ultra Wide Band module, better known by the English name "Ultra Wide Band" (UWB).

[0059] The computer terminal described herein is, for example, a touch tablet, a computer or any other computer means equipped with a human / machine interface.

Claims

Demands

1. A rivet length selection device (1), comprising: - a frame (2), - a length gauge (5) with a hole passing through (T) an assembly of at least two parts (PI, P2) and opening onto opposite faces (F1, F2) of said assembly to receive a rivet for retaining the two parts, the length gauge (5) having a rod (6) mounted to slide on the frame (2) and having a hooked end (7) projecting from a bearing face (4) of the frame so that the hooked end (7) and the bearing face (4) can bear against the opposite faces (F1, F2) of the assembly when the rod (6) extends into the hole, - a transducer (14) mounted on the frame and arranged to transform the sliding of the rod into an electrical signal representative of a sliding amplitude,- an electronic circuit (15) connected to the transducer (14) and arranged to convert the electrical signal into a value expressed in at least one unit of rivet length and present it on a display (13).

2. Device (1) according to claim 1, wherein the electronic circuit (15) comprises a table relating hole lengths to values ​​expressed as a plurality of rivet length units corresponding to a plurality of predetermined rivet types.

3. Device (1) according to any one of the preceding claims, comprising a housing (9) arranged on the frame (2), the housing (9) comprising the transducer (14), at least a portion of the electronic circuit (15) and the display (13) which is arranged to display the value expressed in rivet length units.

4. Device (1) according to claim 3, wherein the electronic circuit (15) comprises a measuring circuit (16) arranged in the housing (9) and a processing circuit (17) which is remote from the housing (9), the measuring circuit (16) being connected to the transducer (14).

5. Device (1) according to claim 4, wherein the processing circuit (17) is arranged in a computer terminal (22) programmed to communicate with the measurement circuit (16) of the housing (9) via a transmitter (20) connected to the measurement circuit (16) and a receiver (21) connected to the processing circuit (17).

6. Device (1) according to claim 3, wherein the electronic circuit (15) comprises an integrated processing circuit (17) which is arranged to provide the value expressed in rivet length units and which is connected to the display (13) of the housing (9), the electronic circuit (15) being entirely arranged in the housing (9).

7. Device (1) according to any one of claims 4 or 5 or 6, wherein the processing circuit (17) includes a rivet type selection menu and an interface arranged to enable a user to make a selection from the selection menu.

8. Device (1) according to any one of the preceding claims, incorporated in a caliper (100) comprising at least a first set of jaws (101) for measuring an internal diameter.

9. Device (1) according to claim 8, wherein the caliper (100) comprises at least a second set of jaws (102) for measuring an external diameter.

10. Device according to claim 8 or 9, wherein each set of jaws (101, 102) comprises a movable jaw fixed in translation to the rod (6) of the length gauge (5) so that the transducer (14) serves for the measurement of diameter and length.

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