AU2010224348B2

AU2010224348B2 - Portable tooling for adhesively bonding a ring to a yoke of a sleeve for a blade, and a method of bonding the ring

Info

Publication number: AU2010224348B2
Application number: AU2010224348A
Authority: AU
Inventors: Christophe Ducamp
Original assignee: Airbus Helicopters SAS
Current assignee: Airbus Helicopters SAS
Priority date: 2009-09-23
Filing date: 2010-09-21
Publication date: 2011-10-13
Anticipated expiration: 2030-09-21
Also published as: AU2010224348A1; FR2950275A1; EP2301843B1; FR2950275B1; EP2301843A1

Abstract

A B S T R A C T The present invention relates to portable tooling (10) suitable for adhesively bonding one or two rings 5 (11, 12) respectively to one or two cheeks (6, 7) of a yoke (5) of a blade sleeve (2). The tooling (10) comprises a heater (100) , a diffuser (200) fed with hot air by said heater (100) via a delivery duct (300), one ring support (401, 402) per ring for bonding arranged at 10 a respective end of said diffuser (200), at least one temperature sensor (501, 502) for determining the temperature of the ring for bonding, and control means (600) for controlling said heater (100) and receiving information from said temperature sensor(s) (501, 502). 4 5 3 Fig. 1 720 2' 7"' 401 6o 5 270 2 2 1 0 8 0 3 720 5-801 L1 L2 803 103 i . L3 102 Fi.

Description

pool Seclion 29 Regulation 3.2(2) AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Portable tooling for adhesively bonding a ring to a yoke of a sleeve for a blade, and a method of bonding the ring The following statement is a full description of this invention, including the best method of performing it known to us: P111ABAU0610 1 PORTABLE TOOLING FOR ADHESIVELY BONDING A RING TO A YOKE OF A SLEEVE FOR A BLADE, AND A METHOD OF BONDING THE RING The present invention relates to portable tooling 5 for adhesively bonding a ring to a yoke of a sleeve for a rotor blade, and more particularly to a yoke for fastening a blade damper for a rotor of a rotorcraft of the helicopter type. The invention also provides a method of bonding such rings. 10 A rotorcraft includes at least one main rotor for providing it with lift and indeed with propulsion if it is a helicopter. 15 Such a rotor generally has a plurality of blades, with each blade being fastened to the hub of the rotor by means of a sleeve, sometimes referred to as a cuff. With reference to document FR 2 898 581, it should be observed that the sleeve may optionally be incorporated in the 20 blade itself. Furthermore, it is also common practice to fit a rotor with a plurality of dampers, sometimes referred to as "frequency adapters". Under such circumstances, and by way of example, each damper is fastened to the sleeve 25 of one blade and to the hub of the rotor, or indeed to the sleeve of one blade and to the sleeve of an immediately adjacent blade for dampers of the kind conventionally referred to as "inter-blade dampers". Thus, each has at least one end surrounding a ball 30 joint, said ball joint being held by a pin between two cheeks of a yoke of a blade sleeve . The person skilled in the art sometimes refers to the cheeks of such a yoke as "lugs". More precisely, each cheek being fitted with an 35 insert that is mounted by force in an orifice of the cheek, and being also fitted with a fastener ring that is suitable for protecting said insert, each ball joint is 2 arranged between two rings, and a pin then passing through the insert in the two cheeks, through the associated rings, and also through the ball joint. Such a device for fastening a ball joint to a yoke 5 is most effective. Nevertheless, it is sometimes found that the end of the damper surrounding the ball joint rubs against the rings of the yoke of the sleeve. This leads to the rings being damaged and in the long term such damage requires 10 the rings to be replaced. In order to make such a replacement, the person skilled in the art removes the blade and its sleeve from the hub. Thereafter a new ring is bonded adhesively under pressure and at ambient temperature against the 15 cheek that needs to be fitted therewith. The duration of the polymerization cycle at ambient temperature for the adhesive used lasts for about seven days. This results in the blade being unavailable and consequently in the rotorcraft being unavailable for a 20 considerable length of time. It can be understood that this unavailability is penalizing for the user of the rotorcraft, who therefore has a tendency to shorten the duration of the polymerization cycle. It should be observed that prior art techniques seek 25 to use an adhesive that polymerizes at ambient temperature in order to avoid damaging the sleeve of the blade by high temperature. By way of example, the technological background includes document US 2001/010251 in which two bases clamp 30 between them the two parts for bonding together, each base including infrared heater means and air cooling means. Document US 3 607 545 presents a structure for assembling together elements making up a rotor blade. 35 An object of the present invention is thus to 3 propose tooling that overcomes the above-mentioned limitation by enabling at least one ring of a yoke for fastening a damper of a rotorcraft rotor in a duration that is short and that does not involve the rotorcraft 5 being made unavailable for a long period of time. Thus, the invention relates to portable tooling suitable for adhesively bonding one or two rings respectively to one or two cheeks of a yoke of a blade sleeve, each cheek having first and second surfaces, the 10 first surfaces of the first and second cheeks facing each other, each ring being placed around a pin orifice formed in the corresponding cheek. As a result, the invention lies in the restricted and particular technical field of rings bonding on the 15 cheeks of a sleeve for a blade. It is the final location of the ring that makes adhesively bonding the ring most unusual and difficult, since under no circumstances should the adhesive bonding put the physical integrity of the sleeve at risk. 20 The portable tooling is remarkable in particular in that it comprises: * a heater, for example a heater sold under the reference Hot Gun 1000; - a diffuser defining an inside space fed with hot 25 air by said heater via a delivery duct for heating said ring for bonding, the inside space representing a heating tunnel; - one ring support per ring for bonding arranged at one end of said diffuser; 30 - at least one temperature sensor for determining the temperature of the ring for bonding; and - control means for controlling said heater and receiving information from said temperature sensor(s), for example a control unit sold under the reference 35 AHB380-D by Aeroform France. Consequently, an operator places a ring in the ring support. The operator then heats the ring successively 4 via the heater, the delivery duct, and the diffuser, the heater being controlled by the control means that apply the hot polymerization cycle appropriate for the adhesive used. 5 Thus, the operator arranges the tooling in the yoke of a sleeve and bonds the ring against a first surface of a cheek of the yoke at high temperature, e.g. by using an adhesive of the Hysol@ type. As a result the adhesive polymerizes in about one hour instead of seven days as in 10 the prior art, and that is clearly' a considerable advantage. Surprisingly, bonding the ring at high temperature is made possible by the tooling, since the tooling enables the ring to be heated without heating the body of 15 the sleeve. In addition, as described below, there is no need for the sleeve to be removed in order to bond the ring because the tooling is of a portable nature, thereby optimizing the total length of time required for 20 replacing the ring. The tooling optionally presents one or more of the following additional characteristics. Advantageously, the tooling includes first and second ring supports, said first ring support being 25 arranged at a first end of said diffuser, said second ring support being arranged at a second end of said diffuser. Thus, the diffuser heats two rings simultaneously, thereby enabling both rings of a yoke to be replaced in a single operation. 30 Furthermore, each ring support may comprise a tray that closes one end of said diffuser, said tray having a first layer in contact with said inside space and a second layer suitable for being in contact with a first surface of a cheek, said second layer including a recess 35 matching the shape of said ring for bonding, and said first layer having at least one hole putting said inside space into communication with said recess.

5 The hot air delivered by the heater penetrates into the inside space of the diffuser and thus reaches the ring for bonding via the hole(s) formed in the first layer of the tray. 5 Each ring support then has the function firstly of positioning the ring for bonding, and secondly of conveying hot air to said ring. The heater tool thus heats the ring at the core, said ring then heating the adhesive to the required 10 temperature. Additionally, each ring support includes a chimney secured to said tray and extending axially from said first layer away from said diffuser so as to be suitable for penetrating into said pin orifice of a cheek, said 15 chimney including an axial orifice passing right through it and opening out into said inside space. The ring support then presents a generally T-shaped section. When the ring support is installed, the chimney passes not only through the pin orifice but also through 20 the ring for bonding. Because of the axial orifice, the hot air in the inside space of the diffuser penetrates into the inside of the chimney, thereby enhancing heating of the ring. In addition, the chimney optionally has a first 25 diameter that is smaller than a second diameter of the pin orifice in which the chimney is suitable for extending. Under such circumstances, the chimney advantageously includes at least one slot formed through its periphery 30 and opening out into said axial orifice. The slot then represents a duct connecting the axial orifice to the pin orifice. Consequently, the hot air can heat the ring for bonding in three distinct ways: 35 . by passing via the hole(s) through the first layer of the ring support; 6 - by passing through the hollow body of the chimney heated by the air coming from the diffuser that flows along its axial orifice; and - by the hot air leaving the chimney via its slot(s) 5 and reaching the ring by moving down through the pin orifice. Furthermore, the tooling may include one cap per ring for bonding, the cap being suitable for being placed against a second surface of a given cheek, thereby 10 closing the pin orifice of said given cheek, said cap being fastened to a ring support in order to press the ring for bonding against the first surface of the given cheek. By fastening the cap to the ring support, e.g. by 15 screw-type clamping means, the ring support is pressed against the first surface of a cheek and the cap is pressed against the second surface of the cheek. By dimensioning the clamping means appropriately, it is possible to guarantee the pressure required for bonding 20 the ring. Furthermore, the cap closes the pin orifice. Thus, if the ring support is provided with a chimney suitable for diffusing hot air in the pin orifice, then the cap prevents the hot air from escaping from the pin orifice 25 via the second surface. The tooling constrains the hot air to remain in the vicinity of the ring for bonding, and thus preserves the sleeve from any high temperature that might damage it. In order to optimize the flow of hot air in the pin 30 orifice, the cap has a face suitable for being placed against a second surface of a cheek, and said face is partially hollowed out in its center. It should also be observed that when the ring support possesses a chimney, the cap may have clamping 35 means passing therethrough that are suitable for screw fastening in the chimney. For example, a thread may be 7 arranged around the axial orifice of the chimney and the clamping means may be screwed into said axial orifice. In a variant, said cap includes a projecting key suitable for co-operating with an edge of a cheek, where 5 key means are commonly constituted by a device for preventing an instrument being used wrongly. Consequently, the edge of the cheek that connects the first surface of the cheek to its second surface presents a shape, and the projecting key presents a 10 complementary shape, so as to position the cap in the position required by the manufacturer. The projecting key projects from the cap in order to fit closely against the shape of the edge, thereby positioning the cap in a single position. 15 The operator then necessarily positions the cap appropriately. In order to guarantee the bonding pressure exerted on the ring, the tooling optionally includes a rated spring suitable for being arranged in a pin orifice 20 between said cap and the associated ring support. In addition, the tooling may include support means having at least one leg suitable for being engaged in said sleeve instead of a blade, said support means being provided with fastener means secured to said leg, said 25 fastener means being provided with a slideway suitable for receiving said heater. Under such circumstances, the operator removes the blade from the sleeve and then fastens the support means to the sleeve, by engaging it instead of the blade. 30 Thereafter the heater is fastened via the support means. In order to determine the temperature of the ring accurately during bonding, the temperature sensor is arranged in the ring support. The temperature sensor, e.g. a thermocouple, then measures the temperature of the 35 ring support, which temperature corresponds substantially to the temperature of the ring for bonding.

8 Finally, in order to bond two rings adhesively to a yoke, the tooling may comprise: . first and second ring supports, said first ring support being arranged at a first end of said diffuser, 5 said second ring support being arranged at a second end of said diffuser; - first and second temperature sensors respectively arranged in the first and second ring supports; and - first and second caps suitable for being fastened 10 respectively to the first and second ring supports. In addition to the portable and removable tooling, the invention also provides a method implementing said tooling and stemming from the same inventive concept, i.e. using tooling for hot-bonding a ring. 15 The invention provides a method of using portable tooling to adhesively bond first and second rings respectively to first and second cheeks of a yoke of a blade sleeve, each cheek having first and second surfaces, the first surfaces of the first and second 20 cheeks facing each other, each ring being placed around a pin orifice formed in the corresponding cheek, said portable tooling comprising a heater, a diffuser fed with hot air by said heater via a delivery duct, first and second ring supports arranged respectively at first and 25 second ends of said diffuser, first and second caps suitable for being fastened respectively to the first and second ring supports, first and second temperature sensors arranged respectively in the first and second ring supports, and control means for controlling said 30 heater and receiving information from said first and second temperature sensors. This method is remarkable in particular in that it comprises a preparatory stage in which the following steps are performed: 35 - applying adhesive between each ring and a first surface of said cheeks, i.e. against the ring for bonding 9 and/or against the first surface against which the ring is to be bonded; - placing a ring in each ring support and pressing the first and second ring supports against the first 5 surfaces respectively of the first and second cheeks, i.e. the first ring support against the first surface of the first cheek and the second ring support against the first surface of the second cheek; - placing said first and second caps against the 10 second surfaces respectively of the first and second cheeks, and then fastening the first and second caps to the first and second ring supports respectively, the first cap and the first ring support pressing the first ring against the first surface of the first cheek and the 15 second cap and the second ring support pressing the second ring against the first surface of the second cheek; - arranging said diffuser between the first and second ring supports; and 20 - connecting the heater to the diffuser via said delivery duct and then connecting said heater and the first and second temperature sensors to the control means; and then an adhesive bonding stage during which the 25 control means cause the heater to deliver air to the diffuser at a predetermined temperature for a predetermined cycle that corresponds to the adhesive used. For example, the control means requires a temperature of 90 degrees Celsius to be reached at a 30 speed of 5 degrees Celsius per minute and then requires this temperature of 90 degrees Celsius to be maintained for one hour before requiring a return to ambient temperature at a speed of 5 degrees Celsius per minute. The predetermined temperature and the predetermined 35 cycle are clearly and easily determined by the operator insofar as they are set by the manufacturer of the adhesive that is used.

10 The invention and its advantages appear in greater detail in the context of the following description 5 showing an embodiment given by way of illustration with reference to the accompanying figures, in which: - Figure 1 shows a blade sleeve provided with rings that are to be replaced; - Figure 2 is a diagrammatic view of tooling of the 10 invention arranged on a sleeve; - Figure 3 is a section view of the diffuser, of the support rings, and of caps of the tooling arranged on a yoke of a sleeve; and - Figure 4 is an exploded view of a diffuser, 15 support rings, and caps of the tooling. Elements that are present in more than one of the figures are given the same references in each of them. 20 Figure 1 shows a rotorcraft blade 1 fastened to a sleeve 2 by pins 3, the sleeve 2 itself being constrained to rotate with a hub 4. The sleeve 2 includes a yoke 5 for connection to a damper, the damper being an inter-blade damper, for 25 example. Consequently, the yoke 5 possesses first and second cheeks 6 and 7, each provided with first and second surfaces 6' & 6", 7' & 7". The first surface 6' of the first cheek 6 faces the first surface 7' of the second 30 cheek 7, with the gap between said first surfaces 6' and 71 then being suitable for receiving a ball joint for fastening the damper. A first ring 11 is adhesively bonded to the first surface 6' of the first cheek 6, and a second ring 12 is adhesively bonded to the first 35 surface 7' of the second cheek 7. In order to fasten the ball joint of a damper, an operator positions a first flat of the ball joint against 11 the first ring and a second flat of the same ball joint against the second ring. Thereafter, a pin is inserted successively through a first pin orifice 8 going from the first surface 6' to the second surface 6" of the first 5 cheek 6, through the first ring 11 surrounding the first pin orifice 8, then through the ball joint, and subsequently through the second ring 12 surrounding a second pin orifice 9 going from the first surface 7' to the second surface 71" of the second cheek 7, and finally 10 through the second pin orifice 9. It should be observed that the first and second pin orifices 8, 9 are advantageously defined by first and second inserts 8', 9' mounted by force within the cheeks. Such a damper fastener device satisfies 15 requirements. Nevertheless, it is found that the end of the damper surrounding the ball joint sometimes comes into contact with the first and second rings 11, 12. The resulting damage to the first and second rings 11, 12 leads to them being replaced. 20 Figure 2 shows portable and removable tooling 10 of the invention for adhesively bonding the first and second rings 11, 12 in a minimum length of time without running the risk of damaging the body 2' of the sleeve 2. The tooling comprises a removable and portable local 25 stove 20 suitable for positioning and heating the first and second rings 11, 12 so as to bond them to the first surfaces 6', 7' of the first and second cheeks. The local stove 20 includes a diffuser 200 having a first semicylindrical shell 201 and a second 30 semicylindrical shell 202. It should be observed that the first shell 201 has two U-shaped fastener members 223, each fastener member 223 co-operating with a fastener wheel 221 of the second shell 202. When the first and second shells 201, 202 are 35 assembled together, they form a heating tunnel that defines a cylindrical inside space.

12 Furthermore, the first and second ends 211, 212 of the diffuser 200 are closed by one ring support per ring for bonding, i.e. first and second ring supports 401, 402, these first and second ring supports 401, 402 5 receiving the first and second rings 11, 12. The assembly including the diffuser 200 and the first and second ring supports 401, 402 is then arranged between the first surfaces 6', 7' of the first and second cheeks 6, 7. 10 In addition, the portable stove includes one temperature sensor per ring for bonding, i.e. first and second temperature sensors 501, 502. By way of example, the first and second temperature sensors 501, 502 are thermocouples arranged in the thickness of respective 15 ones of the first and second ring supports 401, 402. The first and second temperature sensors 501, 502 are then connected via first and second electrical connections L1, L2 (which may be wired or wireless connections) to control means 600 for controlling the 20 tooling 10. Under such circumstances, the tooling 10 includes a heater 100 suitable for sending hot air into the inside space 203 of the diffuser 200 via a delivery duct 300, such as a flexible pipe. 25 optionally a heater is used that is provided with an electrical connector 101 for connection via a third electrical connection L3 to the control means 600, with a connector 102 for being fed with air by conventional means (not shown in the figures), and with an exhaust 103 30 suitable for discharging air. Since the heater is itself known, reference may be made to the literature for further information about it. An operator then indicates a predetermined heating cycle to the control means, by specifying the temperature 35 gradients to be applied, the dwell temperature to be reached, and the duration during which the dwell temperature should be maintained.

13 The control means 600 control the operation of the heater 100 as a function of the temperature information reaching them from the first and second temperature sensors. 5 Optionally, in order to guarantee good positioning of the ring supports and to avoid heat coming from the diffuser 200 being diffused towards sensitive zones of the sleeve 2, the tooling 10 includes one cap per ring support, i.e. first and second caps 701, 702, as shown in 10 Figure 2. Consequently, the first cap 701 has a face that is adjacent to the second surface 6" of the first cheek 6 so as to close the first pin orifice 8 hermetically level with said second surface 6". 15 The first cap 701 is then fastened to the first ring support 401 by clamping means 720. The first ring support 401 and the first cap 701 then clamp the first cheek 6, with the first ring support 401 pressing the first ring 11 against the first surface 6' of the first 20 cheek 6 with the required level of pressure. For safety purposes, the clamping ring may be connected to the associated cap by a tie, e.g. a chain. Similarly, the second cap 702 has a face that is adjacent to the second surface 7" of the second cheek 7 25 so as to close the second pin orifice 9 hermetically at said second surface 7". The second cap 702 is then fastened to the second ring support 402 by clamping means 720. The ring support 402 and the second cap 702 then clamp the second cheek 7, with the second ring support 30 402 pressing the second ring 12 against the first surface 7' of the second cheek 7 with the required pressure. Finally, the tooling 10 advantageously includes support means 800. In order to optimize bonding operations an operator 35 merely dismantles the blade 1 and thus leaves the sleeve 2 fastened to the hub. Consequently, the stove of the tooling 10 may be found at a height of several meters 14 above the ground. The support means 800 then serve to position the heater 100 close to the stove. The support means 800 are provided with at least one blade 801 extending in a first direction, e.g. 5 cylindrical bushings directed in a vertical direction. Fastener means 802 extending along a second direction orthogonal to the first direction are secured to the legs 801 of the support means 800, with the fastener means 802 being constituted, for example, by a thin plate extending 10 in a horizontal direction with its ends being provided with slideways 803, each suitable for receiving a heater. Once the blade has been removed, the operator fastens the support means 800 to the sleeve 2 by engaging the legs 801 instead of the blade 1. The operator then 15 places a heater 100 in a slideway 803 so as to place the heater close to the cheeks against which a ring is to be bonded. It can be seen that it is possible to arrange two heaters on the support means, so as to use two portable 20 stoves 20 in order to replace the rings of two distinct yokes of the sleeve 2. Figure 3 is a view of a portable stove 20 in a preferred embodiment arranged on a yoke for bonding first and second rings 11, 12, with Figure 4 being an exploded 25 view of the portable stove 20. Thus, in order to bond the first and second rings 11, 12, an operator spreads adhesive over the first and second rings 11, 12 and/or over the first and second surfaces 6', 7' of the first and second cheeks 6, 7, e.g. 30 using adhesive of the Hysol@ type. The operator then places the first and second rings 11, 12 in the first and second ring supports 401, 402. The ring support 401 has a tray 410 closing a first end 211 of the diffuser 200. This tray 410 has a first 35 layer 411 and a second layer 412, the first layer 411 being in contact with the diffuser 200 and in particular with its inside space 203, while a recess 413 having the 15 shape of the rings is formed in the second layer 412 for receiving the first ring 11. Furthermore, at least one hole 414 passes through the first layer 412 in its thickness direction so as to 5 connect the inside space 203 to the recess 413, e.g. four holes as shown in Figure 4. The first ring support 401 also has a chimney 420 passing right through the tray 410 and projecting from the second layer 412 of the tray 410. Thus, the chimney 10 420 extends axially away from the first layer 411 so as to pass through the second layer 412 and finally project from the tray 410. Consequently, the first ring support 401 is T-shaped. This chimney 420 includes an axial orifice 421 15 passing along its entire length, together with at least one slot 422 formed through its periphery 423, in the projecting zone of the chimney that projects from the tray 410. Thus, after placing the first ring 11 in the recess 20 413 of the first ring support 401, the operator presses the second layer 412 of the first ring support 401 against the first surface 6' of the first cheek 6. Consequently, the projecting zone of the chimney penetrates into the first pin orifice 8 of the first 25 cheek 6, said first pin orifice 8 being defined radially by a first insert 8' . The axial orifice 421 of the chimney 420 is then suitable for opening out into the inside space 203 of a diffuser, the slots 422 in the chimney 420 opening out into said axial orifice 421 and 30 into the first pin orifice 8. The second ring support 402 is identical to the first ring support 401, so after -placing the second ring 12 in the recess of the second ring support 402, the operator presses the second layer 412 of the second ring 35 support 402 against the first surface 7' of the second cheek 7.

16 At this stage of installing the portable stove 20 on the yoke of the sleeve 2, the operator makes use of first and second caps 701, 702. Thus, one face of the first cap 701 is placed 5 against the second face 6" of the first cheek 6 so as to close the first pin orifice 8 hermetically. Thereafter, the operator fastens the first cap 701 to the first ring support 401 with clamping means 720, the clamping means 720 passing through the first cap 701 so as to be screwed 10 into a thread in the chimney 420 of the first ring support 401 surrounded the radial orifice 421. By tightening the clamping means as much as possible, the operator ensures that the first ring 411 has the pressure needed for adhesive bonding applied 15 thereto. Nevertheless, and for reasons of safety, it is possible to arrange a rated spring in the pin orifice 8 between the second layer of the tray of the first ring support 401 and the first cap 701. It should be observed that the first cap has a key 20 730 projecting therefrom that is shaped to match the shape of the first edge 6" ' of the first cheek 7, this projecting key co-operating with said first edge to ensure that the cap is properly positioned. Furthermore, in order to optimize the flow of hot 25 air in the first pin orifice 8 during bonding, the first cap 701 is hollowed out in part so as to present a recess 711 facing the first pin orifice 8. Since the second cap 702 is identical to the first cap, the operator repeats the above-described operations 30 to fasten the second cap 702 to. the second ring support 402. Thereafter, the operator arranges the diffuser 200 between the first and second ring supports 401, 402 in order to finalize installing the portable stove 20 of the 35 tooling 10. For this purpose, it should be observed that each ring support 401, 402 includes a peripheral circular 17 recess 450 in its first layer 411 suitable for coming into contact with the ridges of the first and second shells 201, 202 of the diffuser 200. Advantageously, a rail 430 borders part of the peripheral circular recess 5 450, said rail following a semicircle in a zone bordered by the ring supports 401, 402. It should be observed that the projecting keys of the first and second caps 701, 702 when associated with determined clamping of the clamping means 720 of the 10 first and second caps give rise to very accurate positioning of the first and second ring supports 401, 402. Under such circumstances, the rails 430 of the first and second ring supports 401, 402 face each other. The operator then places the second shell 202 in the 15 peripheral circular recesses 450 that are not bordered by the first and second ring supports 401, 402, and then causes the second shell 202 to turn through 180 degrees. The second shell 202 is then arranged between the bordered zones of the first and second ring supports 401, 20 402. Thereafter, the operator places the first shell 201 in the peripheral circular recesses 450 that are not bordered of the first and second ring supports 401, 402, and then fastens the second shell 202 to the first shell 25 201 using the fastener wheels 221. With the portable stove 20 now in place, the operator connects an endpiece 250 of the first shell 201 to the heater 100 via the delivery duct 300. Finally, the operator connects the heater 100 and 30 the first and second temperature sensors 501, 502 to the control means 600. Then using the control means 600, the operator applies the heating cycle as predetermined by the manufacturer of the adhesive being used, so as to stick 35 the ring in a short length of time at a high temperature, i.e. at a temperature that is higher than ambient temperature.

18 Naturally, the present invention may be subjected to numerous variants as to its implementation. Although only one embodiment is described above, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means 5 described by equivalent means without going beyond the ambit of the present invention. Although Figures 2 to 4 show tooling provided with two ring supports, and consequently two caps, it is conceivable to use a single ring support arranged at one end of the diffuser if it is desired to bond only one ring. The other end of the 10 diffuser is then closed by a plug. Such a plug may be a ring support of the above-described type with the holes and the axial orifice therein being closed. A cap may also be fastened on such a plug. Comprises/comprising and grammatical variations thereof when used in 15 this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims

1. Portable tooling suitable for adhesively bonding one or two rings respectively to one or two cheeks of a yoke of a sleeve of a blade, each cheek having first and second surfaces, the first surfaces of the first and second cheeks 5 facing each other, each ring being placed around a pin orifice formed in the corresponding cheek, wherein the portable tooling comprises: a heater; a diffuser defining an inside space fed with hot air by said heater via a delivery duct for heating said ring for bonding; one ring support per ring for bonding arranged at one end of said diffuser; at least one temperature sensor for determining the 10 temperature of the ring for bonding; and control means for controlling said heater and receiving information from said temperature sensor(s).

2. Tooling according to claim 1, including first and second ring supports, said first ring support being arranged at a first end of said diffuser, said second ring support being arranged at a second end of said diffuser. 15

3. Tooling according to claim 1, wherein each ring support comprises a tray that closes one end of said diffuser, said tray having a first layer in contact with said inside space and a second layer suitable for being in contact with a first surface of a cheek, said second layer including a recess matching the shape of said ring for bonding, and said first layer having at least one hole putting said 20 inside space into communication with said recess.

4. Tooling according to claim 3, wherein each ring support includes a chimney secured to said tray and extending axially from said first layer away from said diffuser so as to be suitable for penetrating into said pin orifice of a cheek, said chimney including an axial orifice passing right through it and opening out 25 into said inside space.

5. Tooling according to claim 4, wherein said chimney includes at least one slot formed through its periphery and opening out into said axial orifice. 20

6. Tooling according to claim 1, including one cap per ring for bonding, the cap being suitable for being placed against a second surface of a given cheek, thereby closing the pin orifice of said given cheek said cap being fastened to a ring support in order to press the ring for bonding against the first surface of the 5 given cheek.

7. Tooling according to claim 6, wherein said cap has a face suitable for being placed against a second surface of a cheek, and said face is partially hollowed out in its center.

8. Tooling according to claim 6, wherein said ring support has a chimney and 10 said cap has clamping means passing therethrough and suitable for being screwed into said chimney.

9. Tooling according to claim 6, wherein said cap includes a projecting key suitable for co-operating with an edge of a cheek.

10. Tooling according to claim 6, including a rated spring suitable for being 15 arranged in a pin orifice between said cap and the associated ring support.

11. Tooling according to claim 1, including support means having at least one leg suitable for being engaged in said sleeve instead of a blade, said support means being provided with fastener means secured to said leg, said fastener means being provided with a slideway suitable for receiving said heater. 20

12. Tooling according to claim 1, wherein said temperature sensor is arranged in said ring support.

13. Tooling according to claim 1, comprising: first and second ring supports, said first ring support being arranged at a first end of said diffuser, said second ring support being arranged at a second end 25 of said diffuser; first and second temperature sensors respectively arranged in the first and second ring supports; and 21 first and second caps suitable for being fastened respectively to the first and second ring supports.

14. A method of using portable tooling to adhesively bond first and second rings respectively to first and second cheeks of a yoke of a sleeve for a blade, 5 each cheek having first and second surfaces, the first surfaces of the first and second cheeks facing each other, each ring being placed around a pin orifice formed in the corresponding cheek, said portable tooling comprising a heater, a diffuser fed with hot air by said heater via a delivery duct, first and second ring supports arranged respectively at first and second ends of said diffuser, first and 10 second caps suitable for being fastened respectively to the first and second ring supports, first and second temperature sensors arranged respectively in the first and second ring supports, and control means for controlling said heater and receiving information from said first and second temperature sensors; said method comprising a preparatory stage in which the following steps are 15 performed: applying adhesive between each ring and a first surface of said cheeks; placing a ring in each ring support and pressing the first and second ring supports against the first surfaces respectively of the first and second cheeks; placing said first and second caps against the second surfaces 20 respectively of the first and second cheeks, and then fastening the first and second caps to the first and second ring supports respectively, the first cap and the first ring support pressing the first ring against the first surface of the first cheek, and the second cap and the second ring support pressing the second ring against the first surface of the second cheek; 25 arranging said diffuser between the first and second ring supports; and connecting the heater to the diffuser via said delivery duct and then connecting said heater and the first and second temperature sensors to the control means; and then an adhesive bonding stage during which the control means cause 30 the heater to deliver air to the diffuser at a predetermined temperature for a predetermined cycle that corresponds to the adhesive used. 22

15. Portable tooling substantially as hereinbefore described with reference to what is shown in the accompanying drawings.

16. A method of using portable tooling substantially as hereinbefore described with reference to what is shown in the accompanying drawings. 5 EUROCOPTER WATERMARK PATENT AND TRADE MARKS ATTORNEYS P33717AU00