Abstract:
A device for assembling two constructional elements is equipped with an assembly control system (CR) comprising a sensor ( 26 ) for measuring a physical assembly control parameter and a radiofrequency label ( 14 ) communicating with said measuring sensor ( 26 ). The control system (CR) is capable of determining a characteristic curve representative of the change in the physical control parameter during the assembly of the two constructional elements. The radiofrequency label ( 14 ) is capable of transmitting a control signal (SC) representative of said characteristic curve to a control unit ( 31 ) situated remotely for comparison with a predetermined specific curve.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a U.S. National Phase Patent Application based on International Application Serial No. PCT/EP2007/000622 filed Jan. 25, 2007, the disclosure of which is hereby explicitly incorporated by reference herein. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention concerns an assembly device for assembling two structural elements, the assembly device being equipped with an assembly control system including a measuring sensor for measuring a physical parameter serving to verify assembly and a radio frequency tag communicating with the measuring sensor. 
         [0004]    2. Description of the Related Art 
         [0005]    The measuring sensors currently used in the control systems integrated into assembly devices operate on a binary principle, i.e. an all or nothing principle. These control systems operate to determine remotely whether the measuring sensor is in the activated or inactivated state. 
         [0006]    Depending on the arrangement of the device itself and the operation of the integrated control system, the state of the sensor sometimes cannot be used to determine with certainty whether or not the assembly device is in the assembled state. For example, with many known assembly devices, it is possible for the measuring sensor to change states even though the device is not in the assembled state. 
         [0007]    Furthermore, such measuring sensors cannot be used to qualitatively control the assembly performed. In many known applications, it is possible for assembly to be poorly executed (for example, due to failure to satisfy mounting conditions) without this being detectable by the control system. In such a case, the measuring sensor does change states at the time of assembly, and the control system shows that assembly has been completed. But the risk remains that the device will subsequently deteriorate with time, or even fall apart, due to poor mounting conditions. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides improved control of the assembly performed by assembly devices designed to assemble two structural elements. 
         [0009]    According to the invention, this aim is achieved by the fact that the control system is capable of determining a characteristic curve representative of the change in the verifying physical parameter at the time of the assembly of the two structural elements, and in that the radio frequency tag is capable of transmitting a control signal representative of said characteristic curve to an external control unit for comparison with a predetermined specific curve. 
         [0010]    The predetermined specific curve recorded in the control unit is established for assembly conditions that correspond to normal assembly satisfying all the anticipated requirements. With a control system according to the invention, therefore, when the comparison between the predetermined specific curve and the characteristic curve received is positive, it can be concluded with certainty that the device is in the assembled state and that assembly has been qualitatively well executed. 
         [0011]    In one form thereof, the present invention provides an assembly device for assembling two structural elements, the assembly device being equipped with a control system (CR) for verifying assembly, including a measuring sensor for measuring a physical parameter serving to verify assembly and a radio frequency tag communicating with the measuring sensor, characterized in that the control system (CR) is capable of determining a characteristic curve representative of the change in the physical parameter at the time of assembly of the two structural elements, and in that the radio frequency tag is capable of transmitting a control signal (SC) representative of the characteristic curve to an external control unit for comparison with a predetermined specific curve. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]    The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0013]      FIG. 1  is a front view of a first embodiment of the assembly device according to the invention; 
           [0014]      FIG. 2  is an exploded perspective view of the assembly device of  FIG. 1 ; 
           [0015]      FIG. 3  is a perspective view of the lower portion of the device of  FIG. 1 ; 
           [0016]      FIG. 4  is a schematic representation of an exemplary control system that can be used in the assembly device of  FIG. 1 ; 
           [0017]      FIG. 5  is a perspective view of a second embodiment of the assembly device according to the invention; 
           [0018]      FIG. 6  is an exploded perspective view from below of the assembly device of  FIG. 5 ; and 
           [0019]      FIG. 7  is a perspective view of a longitudinal section of the assembly device of  FIG. 5 . 
       
    
    
       [0020]    Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
       DETAILED DESCRIPTION  
       [0021]      FIGS. 1 to 3  illustrate a first embodiment of the assembly device according to the invention. The assembly device, referenced  10 , is elongate in shape and is designed for assembling a tube on a support (neither of which is shown), with an upper portion  11  to which the tube is to be mated and a lower portion  12  for fixing the assembly device  10  on the support. In the variant shown, the upper and lower portions  11  and  12  are constituted by two one-piece plastic assemblies, which are rendered integral to each other in the central region of the assembly device  10 . 
         [0022]    The central region of the assembly device  10  forms a rectangular case  13  of small thickness, designed to accommodate a annular radio frequency tag  14 . The case  13  is composed of a rectangular lid  15  belonging to upper portion  11  and a plate  16  complementary in shape to said lid  15  and belonging to lower portion  12 . 
         [0023]    Extending from the external surface of the lid  15  is a holding element  17  of a clip ring  18  of the tube. The clip ring  18  is in the shape of a deformable C, with the opening directed upward. The holding element  17  has an X-shaped cross section for good rigidity. The ends of the clip ring  18  support converging guide fins  19 , which facilitate placing the tube in the clip ring  18  when the two are being mated together. 
         [0024]    Extending from the external surface of the plate  16  is a support web  20  carrying two flexible catches  21  serving to secure lower portion  12  on the support. The flexible catches  21  extend from the distal end of support web  20  in the direction of plate  16 . When support web  20  is inserted in a corresponding hole provided in the support, the flexible catches  21  gradually fold up against the support web  20 . When the flexible catches  21  are released, they go back to their initial configuration by elastic return, thus effecting longitudinal retention of the support between the flexible catches  21  and the plate  16 . 
         [0025]    Plate  16  is secured in lid  15  by any appropriate means, for example by adhesive bonding, welding or clipping. In other variants, lower portion  12  is potted onto lid  15 . A cylindrically shaped centering element  22  is provided inside the lid  15  to effect transverse retention of the radio frequency tag  14 . The latter is placed in the lid  15  before lower portion  12  is secured. In complementary fashion, and in reference to  FIG. 3 , plate  16  comprises a cylindrically shaped main recess  23  to accommodate radio frequency tag  14 . Provided coaxially in the bottom of main recess  23  is a secondary recess  24  that is designed to receive centering element  22  during the securing of upper and lower portions  11  and  12  by the seating of plate  16  in lid  15 . 
         [0026]    An additional recess  25  is provided in one of the corners of plate  16 , on the periphery of main recess  23 . Said additional recess  25  serves to accommodate an acceleration sensor (not shown in  FIG. 3 ) whose function will be detailed later on. The acceleration sensor and the radio frequency tag  14  thus are integrated in the assembly device  10 . 
         [0027]    As illustrated schematically in  FIG. 4 , the acceleration sensor, which is referenced  26  in that figure and which is designed in practice to be seated in additional recess  25 , is connected to the radio frequency tag  14 , which is, for example, a passive tag. Radio frequency tag  14  has an antenna  27  tuned to a predetermined frequency and connected to a chip  28  that contains an individual identification code ID. The acceleration sensor  26  is connected to a microprocessor  29  of the chip  28 . The chip  28  further comprises a memory  30  connected to the microprocessor  29 . The acceleration sensor  26  associated with the radio frequency tag  14  constitutes a control system CR integrated into the assembly device  10 . 
         [0028]    In a known manner, a carrier signal P received by the antenna  27  of radio frequency tag  14  generally serves simultaneously as an interrogation signal and a power supply signal for the radio frequency tag  14 . The latter thereupon sends back a carrier signal, designated hereinafter as control signal SC, for example amplitude-modulated by its ID code. 
         [0029]    The carrier signal P is emitted by a control unit  31  external to the control system CR and situated remotely from the assembly device  10 . In the variant embodiment described, to enable it to communicate by radio frequency with radio frequency tag  14  integral to assembly device  10 , control unit  31  comprises an electronic processing unit, which is preferably microprocessor-equipped and is connected to a memory, to an antenna via a transmission/reception interface, and to a man-machine interface. The man-machine interface of the control unit  31  can include a keyboard, a display screen and/or a speaker. The control signal SC emitted by the antenna  27  of the radio frequency tag  14  is adapted to be received by the antenna of the control unit  31 . 
         [0030]    In practice, the assembly of the tube on the support by means of the assembly device  10  is generally carried out in an area where communication between the radio frequency tag  14  and the control unit  31  is possible. The radio frequency tag  14  and the acceleration sensor  26  are supplied with power via the carrier signal P. At the time of assembly of the tube or the support respectively on the upper  11  and lower  12  portions of the assembly device  10 , the acceleration sensor  26  measures the internal vibrations of the assembly device  10 . At the time of assembly, the acceleration sensor  26  transmits a measurement signal SM to the microprocessor  29 . The latter generates uses the measurement signal SM to generate in real time a characteristic curve representative of the change in acceleration measured by the acceleration sensor  26  during assembly. The microprocessor  29  then generates an excitation signal SE for the antenna  27  that is representative of the characteristic curve generated. From the excitation signal SE, the antenna  27  of the radio frequency tag  14  generates a control signal SC representative of the characteristic curve generated by the microprocessor  29 . The control signal SC is received by the control unit  31 , which by virtue of its processing unit is able to run a comparison between the characteristic curve generated by the control system CR during the assembly of the tube and the support and a predetermined specific curve recorded in the memory of the control unit  31 . The predetermined specific curve is established ahead of time for assembly conditions that correspond to normal assembly satisfying all the anticipated requirements. After being processed by the microprocessor of the control unit  31 , the result of the comparison is indicated to the operator by means of the man-machine interface and/or is recorded in the memory of the control unit  31 . 
         [0031]    When the result of the comparison of the predetermined specific curve and the received characteristic curve run by the processing unit of the control unit  31  is positive, it can be concluded with certainty that the assembly device  10  is in the assembled state and that assembly has been qualitatively well executed. If the result is negative, on the other hand, can be concluded that assembly has not been performed or has not been qualitatively well executed, even though the assembly device  10  is in the assembled state, and, in this case the type of mounting defect can be evaluated (excessive mounting, insufficient mounting, etc.). 
         [0032]    In practice, the assembly of the tube on the support by means of the assembly device  10  may also be carried out in an area where there is no provision for communication between the radio frequency tag  14  and the control unit  31 . In that case, the control system CR includes an integrated power source to power the radio frequency tag  14  and the acceleration sensor  26 . For example, the power source can be integrated into the radio frequency tag  14 , which is then a semi-active tag. In other variants, the power source is external to the radio frequency tag  14  and is delivered to the latter for example via antenna  27  or a second antenna (not shown) provided in the radio frequency tag  14  and tuned to a second predetermined frequency. 
         [0033]    In that variant, at the time of assembly of the tube or the support respectively on the upper  11  and lower  12  portions of the assembly device  10 , the microprocessor  29  uses the measurement signal SM from the acceleration sensor  26  to generate in real time a characteristic curve representative of the change in the measured acceleration. The microprocessor  29  generates and then transfers them to memory  30  data D that are representative of said generated characteristic curve. 
         [0034]    In a subsequent phase, once the assembly device  10  has been placed in an area where communication between the radio frequency tag  14  and the control unit  31  is possible and the carrier signal P is being emitted by the control unit  31  and received by the antenna  27 , carrier signal P serves solely as an interrogation signal. From carrier signal P, the microprocessor  29  generates, on the basis of the data D stored in memory  30 , an excitation signal SE representative of the characteristic curve that was generated in advance. From the excitation signal SE, the antenna  27  of the radio frequency tag  14  generates a control signal SC representative of said characteristic curve. The control signal SC is received by the control unit  31 , which then functions in the manner described hereinabove. 
         [0035]    In some variants, the acceleration sensor  26  communicates by radio frequency with the chip  28  of the radio frequency tag  14  via antenna  27  or a third antenna (not shown) provided in the radio frequency tag  14  and tuned to a third predetermined frequency. 
         [0036]      FIGS. 5 to 7  illustrate a second embodiment of the assembly device according to the invention. The assembly device, referenced  40 , comprises a base  41  designed to be bonded to a support (not shown), from which extends an elongate body  42  that is to be forcibly mated with a sleeve (not shown) provided on a structural element to be assembled with the support. In the variant shown, base  41  has a small thickness and is constituted by a bonded assemblage of a lower base portion  41   a  and an upper base portion  41   b . The bottom face of lower base portion  41   a  is designed to be bonded to the support and its top face is designed to be integrally fixed against the bottom face of upper base portion  41   b . The elongate body extends from the top face of upper base portion  41   b , forming an angle that is slightly inclined from the true perpendicular. The value of the inclined angle depends on the relative arrangement of the support and of the sleeve of the structural element that is to be assembled with the support. 
         [0037]    The elongate body  42  is constituted by a cylindrical portion  43  rising from the top face of upper base portion  41   b  and by a plurality of radial fins  44  (three in number, in the example shown) extending axially in the prolongation of the cylindrical portion  43 . Abutment ribs  45  rise between the top face of upper base portion  41   b  and the base of cylindrical portion  43  to constitute an abutment during the forcible mating of the sleeve. The height of the abutment ribs  45  is adapted, depending on their locations, to compensate for the angle of inclination of elongate body  42 . 
         [0038]    In  FIG. 6 , lower base portion  41   a  is inverted from its use position, i.e. the position it has after being bonded against the bottom face of upper base  41   b . In reference to  FIG. 6 , the bottom face of the upper base  41   b  has an annular recess  46  designed to accommodate the radio frequency tag  14  of the previously described assembly device  10 . Transverse retention of the radio frequency tag  14  in the annular recess  46  is effected by a cylindrically shaped centering element  47  provided at the center. Radio frequency tag  14  is placed in annular recess  46  before lower base portion  41   a  is secured. 
         [0039]    In complementary fashion, the top face of lower base  41   a  comprises a cylindrically shaped main recess  48  designed to receive centering element  47  during the securing of lower and upper base portions  41   a ,  41   b . A hole  49  opening onto the bottom face of lower base  41   a  is provided in the center of the bottom of main recess  48 . 
         [0040]    In addition, a cavity  50  of elongate shape is provided in the material of cylindrical portion  43 , and extends from the center of centering element  47 . The axis of orientation of the cavity  50  is orthogonal to the plane of the base  41 . The opening of the cavity  50  coincides with hole  49 , such that the cavity  50  communicates with the outside when lower and upper base portions  41   a ,  41   b  are secured to each other. The cavity  50  is designed to accommodate a temperature sensor (not shown), whose function will be detailed later on. 
         [0041]    More precisely, the assembly device  40  integrates a control system CR identical to that integrated in the assembly device  10 , with the difference that the acceleration sensor  26  is replaced by the aforementioned temperature sensor. The latter is designed to measure the temperature in proximity to the opening of the hole  49  at the time of the bonding of the bottom face of lower base portion  41   a  to the support. 
         [0042]    In practice, at the time of the assembly of the structural element with the support, the microprocessor  29  generates a characteristic curve representative of the change in temperature measured by the temperature sensor during the bonding of the bottom face of lower base portion  41   a  to the support. Said characteristic curve is transmitted, in real time or subsequently, depending on the application, to the control unit  31  so that a comparison can be made with a predetermined specific curve. The result of this comparison can be used to verify that assembly has been carried out and to assess the quality of the assembly executed. 
         [0043]    Finally, the invention can be applied to any assembly device for assembling two structural elements, with which it is possible at the time of assembly to measure a physical parameter serving to verify assembly. The measuring sensors used in integrated control systems CR can be of the following types, for example: pressure sensor, force sensor, torque sensor, optical sensor, moisture sensor, solar energy sensor, piezoelectric sensor. Moreover, depending on the variants and needs, the measuring sensor, rather than being integrated, can be situated in proximity to the parts per se of the device that are to be assembled. The control system CR is then semi-integrated. 
         [0044]    While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.