FR2715729A1 - Torque indication device. - Google Patents

Abstract

This torque indication device (23) comprises first (22) and second parts (24) connected to each other so as to mutually transmit a torque, torque transmission means (28) connecting said first and second parts, torque detection means (30), disposed on said torque transmission means and responsive to the torque transmitted by these torque transmission means by producing a signal dependent on said transmitted torque, communication means comprising a transmitter of electromagnetic radiation receiving said signal produced by said torque detection means and communicating an output signal dependent on said torque, receiving means which provides an output signal representative of said transmitted torque.

Description

TORQUE INDICATION DEVICE

  The present invention relates to a torque indication device.

  The object of the invention is to provide a new and improved torque indication device.

  According to the present invention, this torque indication device comprises: - first and second parts connected to each other so as to transmit a torque to each other; - torque transmission means connecting said first and second parts to each other; torque detection means arranged on said torque transmission means and reacting to the torque transmitted by said torque transmission means by producing a signal dependent on said transmitted torque; and - communication means comprising an electromagnetic radiation transmitter receiving said signal produced by said torque detection means and communicating an output signal dependent on said torque to a reception means which supplies an output signal representative of said transmitted torque.

  It can be arranged that the frequency of measurement of the torque and / or of the communication of said output signal depends on the value of the torque. Consequently, the energy consumption required for sampling the torque and / or for communicating the output signal is less than the energy consumption which would be necessary if the torque were sampled continuously and / or the output signal was continuously communicated.

  When the torque is less than a predetermined level, the measurement and / or communication frequency can have a first value while when the torque is at or above said predetermined level, the measurement and / or communication frequency can have greater value. For example, the lowest value of the measurement and / or communication frequency can correspond to a period between 50 and 1000 milliseconds, while the highest value can correspond to a period between 1 and 50 milliseconds.

  Typically, this frequency could be 5 hertz when the torque is less than 5% of the total deviation and 100 hertz when the torque is equal to or greater than 5% of the total deviation.

  The microprocessor can be an 8-bit microprocessor and can include an analog-to-digital converter.

  The desired frequency can be in the visible light, infrared or preferably a radio frequency emitted from an antenna band.

  When the device comprises interior and exterior parts of annular configuration, this arrangement facilitates the mounting of the communication means (and control means if these are present) and of an electric battery or battery on the indication device. couple.

  The arrangement of the antenna and other components facilitates sealing so that the device can be easily adapted for use in industry, such as the food industry, where there is a risk of contamination of the products or a damage to the device by process fluids or particles.

  In addition, the device is robust enough to be able to withstand all atmospheric and other ambient conditions in the presence of which it can be used.

  Due to the low measurement and / or communication frequency mentioned above, the device can have a relatively long "inactive" lifespan without significantly reducing the duration of the electric battery. For example, the device can be stored before being installed with the communication means and the active control means, but due to the low current consumption due to the low sampling frequency, the lifetime of the battery. is not significantly reduced.

  The control device can be adapted to detect the battery voltage and the communication means can be adapted to communicate a signal dependent on the battery voltage, so that it can be monitored using the means of receipt if it is necessary to replace the battery.

  When the torque detection means is initially energized, the indication obtained may be unstable and, therefore, the control means will initially energize the torque sensing means and then energize the means of communication.

  Instead of a radio frequency transmission means, other means of communication can be used, for example a display depending on the torque is provided in the device. For example, a liquid crystal display device may be used and the receiving means may read the liquid crystal display using an appropriate scanner and then provide a desired dependent output signal of the couple. The liquid crystal display means may, for example, display an output signal in the form of an appropriate barcode.

  The transmission means may comprise a relatively low power radio frequency oscillator without any power amplification stage since the signal need not be propagated other than a very short distance to the reception means, which is physically located very close to the torque indication device.

  The device according to the present invention also has the following characteristics taken individually or in combination.

  The device can rotate around an axis and the first part comprises a part, radially inner with respect to said axis, and the second part comprises a part, radially outer with respect to said axis, and the torque transmission means comprise at least one torque transmitting member extending radially and circumferentially between said parts for transmitting torque therebetween; the outer part includes a ring; the inner part includes a ring; the internal part is arranged coaxially inside the external part, at least one torque transmitting element extending between this internal part and this external part; the element or each torque transmitting element has, in the axial direction, a thickness which is less than its width in the circumferential direction; the element or each torque transmission element has, in the circumferential direction of the device, a thickness which is less than its width in the axial direction of this device; the inner part and the outer part are further connected to each other by a plurality of connecting elements which extend radially and axially and which confer axial stability to the torque indication device; said connecting elements extending radially and axially have, in the circumferential direction of the device, a thickness which is less than their width in the axial direction of the latter; the first and second parts are connected to each other only by said torque transmitting element and by said connecting elements, when these are present; the inner part comprises a hub on which the outer part is rotatably mounted, the inner part comprising an axially extending portion and arranged radially inside an axially extending portion of the outer part, and at least one torque transmitting element extending between said portions; the element or each torque transmission element has, in the axial direction of the device, a width which is greater than its thickness in the circumferential direction of the latter; the element or each torque transmission element is connected to the interior and exterior parts in a "recessed" manner or in a "simply supported" manner, or else "simply supported" for a first value of relative angular displacement between the interior and exterior elements and in a "recessed" manner for another value of said displacement; the device is provided with two diametrically opposed torque transmission elements; the inner part and the outer part are adapted to be connected to first and second rotary components so as to transmit the torque between these components; the communication means are supplied by means forming an electric battery and supported by the device; the torque indication device is provided with control means by which at least the torque measurement and the communication of said output signal are carried out intermittently; the frequency of measurement of the torque and / or of the communication of said output signal depends on the value of the torque; when the torque is below a predetermined level, the frequency of measurement of said torque and / or of said communication of the output signal has a first value, while when the torque is at or above the predetermined level, said frequency has greater frequency; the torque detection means comprises a strain gauge means; the strain gauge means includes a strain gauge bridge; the output of the bridge is supplied to an amplifier; the amplifier provides an output signal which is applied to a unipolar / bipolar converter so as to give a signal dependent on the direction of the torque which is transmitted; the output signal from the unipolar / bipolar converter is sent to a microprocessor; the microprocessor is an 8-bit microprocessor; the electromagnetic radiation is a radio frequency and is emitted by an antenna; the transmitter is adapted to transmit an amplitude modulation type signal or a frequency modulation type signal; the transmitter comprises a low power radio frequency oscillator which transmits an output signal to an appropriate reception means; the antenna is adapted to radiate the output signal uniformly or substantially uniform circumferentially around the device; the antenna comprises a conductor which extends at least partially circumferentially around the device; the device comprises a circular circumferential surface oriented radially outward or inward and on which the antenna is mounted; the antenna is isolated from the outside by an appropriate insulating means; the antenna is mounted in a battery supply circuit and is used to bring the electric current from the battery to the torque detection means and to the communication means; the antenna comprises two antenna parts, one of said parts constituting a conductor for a current supply of negative polarity from the electric battery and the other of said parts constituting a contact for a current supply of positive polarity from the electric battery; the device is provided with a radially extending opening through which a battery is mounted on the device; said opening is formed in said outer part and the inner part is provided with a cavity, extending radially and aligned radially with said opening, in which a portion of the stack is received and a second portion of the stack being received in the opening of the external part, a retaining means being provided for retaining the battery in the torque indication device; the antenna comprises a retaining means for a battery; the battery can be replaced radially; the device is provided with an end cover mounted on said outer part so as to rotate with the device, the element or each torque transmission element being disposed between the radially extending part and the end cap; the battery and / or the communication means and / or the control means are housed inside the end cap; the control device is adapted to detect the battery voltage and the communication means is adapted to communicate a signal dependent on the battery voltage so that it can be checked with the receiving means whether it is necessary to replace the battery; the control means initially energizes the torque detection means and then energizes the communication means; the device is provided with at least one target for detecting, for example by means of a photoelectric cell, the speed of rotation of the device; means are provided by which the speed of rotation of the device is integrated with the torque to provide an indication of the power; a torque dependent display is present on the device; the display is effected by liquid crystal display means and the receiving means reads the display on the liquid crystal using an appropriate scanner and then displays a desired torque dependent output indication; and the liquid crystal display device displays the output signal as an appropriate barcode.

  The present invention will now be described with reference to the accompanying drawings which show, by way of example, embodiments and in which: FIG. 1 is a cross section of a torque transmission assembly comprising a device for torque indication according to the present invention, the section of this torque indication device being shown along 1-1 of Figure 2; Figure 2 is a view of the torque communication device of Figure 1 in the direction of the arrow A in Figure 1; Figure 3 is a section along line 3-3 of Figure 2; Figure 4 is a section along line 4-4 of Figure 2; Figure 5 is a block diagram of the torque communication device of Figures 1 to 4; Figure 6A is a block diagram relating to the torque communication device of Figures 1 to 4; Figure 6B is a diagram showing part B of Figure 6A in more detail; Figure 7 is a flow diagram showing the cycle of the torque communication device of Figures 1 to 6B; Figure 8 is a view similar to that of Figure 2 but relates to a second embodiment of the invention; Figure 9 is a cross-sectional view of another torque transmission assembly comprising the torque indicating device according to the present invention; Figure 10 is a section along line 10-10 of Figure 9; and FIG. 11 is a partial view, on a larger scale, of a part of FIG. 9.

  Referring now to Figure 1, it can be seen that a torque transmission assembly includes an output member 10 which is driven by an input member 11 via a torque limiting clutch 12. The torque limiting clutch 12 has a clutch plate 13, slidably keyed and not rotating on the input element 11, and a second clutch plate 14 which can rotate relative to the element d entry 11 and is fixed by split pins 15 to a coupling ring 17. The clutch plates 13 and 14 are coupled in a separable manner to each other by balls 18 of torque transmission which can be engaged releasably in recesses 19 of the clutch plates 13, 14 and are guided by a cage plate 20. l

  The coupling ring 17 is coupled by three other cotter pins 21 to an external part 22 of a device 23 for indicating the torque.

  As can best be seen in Figures 2-4, the torque indication device 23 includes the outer part 22 which has an annular shape and an inner part 24 which also has an annular shape. The external part 22 has three openings 25 which extend axially and inside which the three split pins 21 are housed to couple the external part 22 to the coupling ring 17. The internal part 24 is provided with six openings 26 in which are housed six cotter pins 26a for coupling the internal part 24 to the external element 10.

  The outer part 22 and the inner part 24 are mutually coupled by a pair of diametrically opposite torque transmission elements 28 which, as can be better seen in FIG. 3, are relatively thin in the axial direction of the device, it that is to say in a direction parallel to the longitudinal axis XX of the device, and are relatively wide in a circumferential direction, as can be seen in FIG. 2.

  The inner and outer parts are also connected to each other by eight connecting elements or arms 29 which extend radially and longitudinally and which are relatively thin in the circumferential direction, as can be seen in FIG. 2, but which are relatively wide in the axial direction, as can be seen in FIG. 3, and, as a result, the connecting elements 29 provide axial stability in the connection between the inner and outer parts 24, 22.

  The elements 28 for transmitting torque and the connection elements 29 are connected to the external and internal parts 22, 24 by the fact that they form an integral part of it and, consequently, are connected to it in a "built-in" structural mode.

  A strain gauge means 30, comprising a conventional bridge of strain gauges, is applied to each of the torque transmission elements 28, these strain gauges being configured in such a way that their resistance varies as a function of the stress of the elements 28 resulting from the torque that is transmitted.

  The output signal from the strain gauge means 30 is sent to a microprocessor system 31 which is connected to a transmitting antenna 33 which extends circumferentially around the circumference of the external part 22 and is isolated therefrom by a ring isolation 34.

  The antenna 33 comprises two generally semicircular parts, 33a, 33b, which are connected to a negative terminal and to a positive terminal, respectively, of an electric cell or battery B and which constitute a current path extending into the microprocessor system 31.

  An electric battery B is housed, on the one hand, in a blind hole 32, which has a circular cross section and which extends radially with respect to the axis AA and is formed in the interior part 24 and, on the other hand part, in a cylindrical opening 35 which extends correspondingly radially and which is formed in the outer part 22. The electric cell is held in position by the insulating ring 34 and by the part forming the antenna 33a which are held in place by screws 36, 36a-b which are received in threaded inserts 37a-b isolated from the external part 22.

  The threaded insert 37b receives another screw 38a which secures a terminal lug 39a connected, so as to conduct electricity, to the insert 37b and, consequently, to the antenna part 33a, and the lug 39a is connected by a metal wire 40a to a positive terminal of the microprocessor system 31. Similarly, the insert 37b receives another screw 38b which secures a terminal 39b connected by a metal wire 40b to a negative terminal of the microprocessor system.

  A frustoconical spring 41 is housed in the blind hole 32 and bears against the negative terminal of the electric battery B. The spring 41 is connected by another metal wire 40c to a terminal lug 39c which is fixed by another screw 38c to the patch 37b.

  The antenna part 33a has another screw 42 which is screwed into this part and the inner end of which bears against the positive terminal of the electric battery B. The antenna parts 33a and 33b thus ensure the presence of a current path from the respective positive and negative terminals of the electric battery B up to the positive and negative terminals of the microprocessor system 31.

  This mounting of the electric battery B makes the replacement of this battery relatively simple since it is easy to access the battery in the assembly shown in FIG. 1 simply by removing the screw 36a and moving the insulating ring 34 and the antenna part 33a so that the old battery can be removed, this operation being followed by a reattachment of the antenna part. Because access takes place radially, replacement can be carried out without the need to disconnect the torque indication device from the assembly.

  Referring now to Figure 5, we see that there is shown schematically the electrical circuit of the torque transmission device.

  The strain gauge means 30 comprises a conventional arrangement 44 of strain gauges, the output signal of which is supplied to an amplifier 45 and the supply of which takes place via lines 46 and 47. Line 46 is connected to the positive terminal from the battery and supplies positive power to the amplifier 45, to a unipolar / bipolar converter 48 and to a low power radiofrequency oscillator 49 which constitutes a transmitter acting as a means of communication for communicating an output signal which is a function of the torque detected by the strain gauge means. If desired, an emitter of electromagnetic radiation of a frequency other than a radio frequency, such as for example an emitter of electromagnetic radiation in the visible light band, can be provided in association with an appropriate receiver. This arrangement is possible thanks, for example, to a liquid crystal display of numbers or an appropriate barcode, or other similar indication.

  The output signal of the amplifier 45 is sent to the unipolar / bipolar converter 48, the output signal of which is sent, by lines 50 and 51, to an 8-bit microprocessor 52, line 51 carrying a polarity detection bit. or sign bit. The microprocessor 52 is connected to a negative terminal of the electric battery by line 54 and is also supplied with a voltage reference signal by line 53.

  The microprocessor provides a serial output signal to the oscillator 49 by line 55 and the oscillator 49 provides by line 56 a signal which is sent to the antenna 33, for example by lines 40a, 40b, and is transmitted from them in the form of a radio frequency signal. The microprocessor 52 is also connected to the oscillator 49 by line 57.

  The microprocessor system includes a central processing unit (CPU) connected to an address bus, a data bus and a control bus. The address bus is connected to a random access memory (RAM) serving as working memory, to a programmable read only memory (PROM) serving as memory for the operating program of the system and to input and output buses to which lines 50, 51, 53 and 54 are connected. In addition, the microprocessor provides a switched output signal to line 47 or line 57.

  Referring now to FIGS. 6A and 6B, it can be seen that FIG. 6B is a block diagram relating to the amplifier 45, to the unipolar / bipolar converter 48, to the oscillator 49 and to the microprocessor 52. The bridge 44 of gauges stress is connected, as shown in Figure 6B, to the terminals P1, P2, P5, P6 of the differential amplifier constituted by the components located inside the block shown in broken lines in Figure 6B at 45, while that a gain adjustment resistor, in the form of a potentiometer, is connected to terminals P3 and P4. The differential amplifier 45 includes a reference voltage circuit which includes an integrated circuit U4 and which also supplies the unipolar / bipolar converter constituted by the components located inside the block delimited by the line 48 in broken lines in the figure. 6B.

  The converter 48 performs an absolute value and sign detection on the output signal of the amplifier 45 and also conditions a signal so that it covers the full input range of the analog-digital converter of the microprocessor formed by the components being in the block 62 delimited by a line in dashed lines in FIG. 6B. The microprocessor 52 performs an analog-to-digital conversion and produces a series of bits in series on the line 55 to modulate the RF oscillator constituted by the components located in the block 49 delimited by a dashed line in FIG. 6B. The absolute value signal is sent from the converter 48 by line 50, while the polarity detector is supplied by line 51 in Figure 6B.

  Figure 6A also shows how an electric battery B is connected in the circuit.

  The RF oscillator 49 comprises a single transistorized stage using a crystal operating in fundamental mode. Because the complete circuit must operate at very low power levels in order to ensure a long useful life of the battery, for example six months, and the fact that the operating range is not subject to any requirements, no power amplification stage is necessary or desirable. Just enough radio frequency power is generated to fully control a receiver at a distance of 25 mm or less, for example, from the antenna.

  The antenna 33 is loosely coupled to the collector circuit by four turns of wire 33a around a self-induction coil, the other end being connected to the metal part of the sensor assembly which is earthed or which forms a counterweight through the mass of the device with which the device is used. This considerably increases the high frequency radiated power. A narrowband frequency modulation is obtained by modifying the DC point of polarization and, therefore, the parasitic capacitances in the base / emitter and collector / base circuits. The frequency variation is approximately hertz compared to a nominal average central frequency which is itself adjusted correctly using a small variable capacitor across the crystal.

  The receiver R is of any suitable type, for example a super heterodyne simple conversion design called simple "data sheet" using, for example, an MC3361 chip. A fundamental crystal is used to give an intermediate frequency IF of 455 kilohertz. The output of the FM modulator is alternately coupled to a comparator which controls the output at TTL levels. The automatic blocking or silent tuning circuit operates at a high HF (high frequency) noise so as to block the input of the comparator and the desired information can be presented as will be described below.

  The microprocessor controls the operation according to the program in the PROM memory. Referring to the flowchart of Figure 7, we see that the operation takes place as follows.

  The microprocessor clock initially switches power on lines a and b. The microprocessor then receives via line 50 and in analog form the signals representing the absolute value of the torque arriving from the unipolar / bipolar converter 48 and the power supply on line 47 is then cut.

  The microprocessor performs analog-to-digital conversion and translates the torque value into eight-bit series and assigns a sign according to the polarity detector signal applied to line 51. The microprocessor then digitizes the input signal from the circuit voltage reference and translates this information into eight-bit series. The microprocessor compares the torque value with the maximum output indication of the analog / digital stage (A / D) and, if the torque is less than 5% of this indication, the microprocessor cuts the power supply to line b and the system remains in this state until the microprocessor clock reaches the end of a preprogrammed sleep mode which is in the range of 50 to 100 milliseconds, in this example 5 hertz. Then, the microprocessor switches the power on lines 47 and 57 and the cycle is repeated as described above. The bridge is provided with a proportional resistor 58 which can be adjusted to obtain an indication of maximum output from the A / D converter stage for a predetermined torque.

  In a variant, if the comparison of the torque indicates that the torque is not less than 5%, the supply on line 57 is maintained and, after a short delay, which, typically, is within the range of 150 milliseconds, and in this example is 100 hertz, the cycle is repeated by switching the power on the two lines 47 and 57.

  The circuit is supplied, in the present example, by the electric battery B which comprises a thionyl lithium chloride battery having a capacity of 1500 mAh. The battery provides direct current at a voltage between 3.3 and 3.7 volts. This voltage is determined by the inverse of the digitized reference voltage VREF, since all A / D conversions are given by a ratio measurement.

  When the torque is less than a predetermined value, then, as explained above, the circuit, as it is designed, samples the torque at a relatively low frequency, in the present example 5 hertz. However, when, as a result of such sampling, the torque is detected as being greater than the predetermined value, a higher sampling and transmission rate is ordered, in the present example 100 hertz. As a result, because the circuit does not sample and does not continuously transmit a signal, the power consumption of the device is relatively low compared to the consumption that would take place if the sampling was carried out. permanently.

  In the present example, the signal is a frequency modulated signal at a nominal frequency of 27.145 MHz.

  The radiated signal is detected by a receiver R which is placed at a point adjacent to the antenna 33, in the present example 5 mm from the latter but which could, preferably, be distant from it by a distance preferably of from 2 to 10 mm up to 25 mm. The receiver R is supplied with the current from line R1 and is designed to display the detected torque and, if desired, the power and / or the state of the battery, in any desired manner. If desired, the receiver can provide a signal to a printer to obtain a permanent record, and / or to a computer system.

  To allow the display of the power, a reflective target T is placed at a single location, or at several locations spaced circumferentially on the external parts 22, or on any other suitable rotating component of the device. The passage of the target T is detected in front of a photoelectric cell P and the time taken for a complete revolution is thus measured so as to obtain the speed of rotation of the device. The transmitted torque is multiplied by the speed thus determined so that the power transmitted by the device can be displayed.

  The present invention gives the possibility of modifying the sensitivity of the device by an appropriate choice of materials from which the torque transmission assembly is made. In the present example, the torque transmission assembly is made of steel and has an outside diameter of 150 mm with respect to the outside part 22 and, with the spacers having a thickness of 2.0 mm and a width of 10 mm. , provides a torque transmission capacity of 400 NM.

  However, a torque transmission assembly having the same dimensions but made, for example, of aluminum, or of an aluminum alloy, provides a lower torque transmission capacity.

  In a variant, or in addition, the sensitivity of the torque transmission assembly can be adapted by modifying the configuration of this assembly.

  Referring now to Figure 8, we see that there is shown a variant of the embodiment described with reference to Figures 1 to 7, variant in which we used to designate the corresponding parts the same reference numbers as those used in Figures 1 to 7.

  The device of FIG. 8 is essentially the same as that of the embodiment described above except as regards the details of the device 23 for indicating the torque.

  In the present case, the main difference lies in the fact that two torque transmission elements 28 are provided which are relatively wide in the axial direction and relatively thin in the circumferential direction of the device and therefore have a configuration similar with regard to the spacers 29 of the embodiment described above. In addition, two spacers have been provided which are arranged orthogonally to the elements 28. Each torque transmission element 28 can be considered to fulfill the function of both the torque transmission element and the spacer, while, in the embodiment described above, these functions are separate.

  The elements 28 are, here again, an integral part of the external and internal parts 22, 24 and are connected to each other in a "embedded" structural mode.

  In addition, the number of assembly openings 25, 26 is, in the present embodiment, four in each case. The other characteristics of the torque indication device 23 are essentially identical to those described in connection with the first embodiment and are only shown schematically in FIG. 8.

  The mode of operation of this embodiment is identical to that described in connection with the first embodiment, but the configuration described makes the device suitable for relatively low torques.

  For example, if the parts 28, 29 have a thickness of 1 mm and a length of 10 mm in the axial direction, they are suitable for a nominal torque of 1 Nm.

  It will be noted that, in this embodiment, the strain gauges 30 are arranged at a location situated approximately a quarter of the length, along the radial extent of the torque transmission element.

  Referring now to Figures 9 to 11, it can be seen that there is shown another embodiment of the invention, in which a torque transmission assembly comprises an output element 110 rotatably mounted on an element input 111 in the form of a hub using a means forming a bearing 112. The torque is transmitted between the elements 110, 111 by a device 123 for transmitting and indicating torque.

  The device 123, for transmitting and indicating torque, comprises an outer part 122 of generally cylindrical configuration and projecting axially from a portion 124 which extends radially and which constitutes a seat for the bearing means 112 and is rotatably mounted on the hub portion 111. The hub portion 111 also includes a portion 125 which extends axially and which is arranged coaxially with the cylindrical portion 122 extending axially and within this cylindrical part.

  The cylindrical part 122 has two slots 125 which extend radially and which are provided with notches 126, extending in the direction of a cord, so as to allow access to the heads 127 of locking screws 128. locking screws 128 block one of the ends of the elements 129, which transmits the torque and have the shape of generally rectangular strips, inside the slots 125, and the opposite ends of the elements 129 in the form of strips are housed in the slots 130 formed in the parts 125 which extend axially and which the internal element 111 comprises.

  A slight clearance is provided between the inner end of the lamellar elements 129 and the walls of the associated slot 130 so that the inner ends of the torque transmission elements 129 are "simply supported", that is to say say so that they can pivot around the outer edge 130a, 130b in the direction of the relative rotational movement between the inner and outer elements 111, 110. In a variant, the slots can have dimensions such that the inner ends of the elements 129 of torque transmission are adjusted without play in these slots so that the inner ends are mounted in "recessed" mode. In yet another variant, the slots can form a free space or play such with the elements 129 that, during the initial angular displacement of the elements 111, 110, a "simply supported" mode takes place, while during an additional displacement , a "recessed" mode takes place. Similar options can be provided for the other ends of the elements 129 by appropriately connecting the external ends to the external element. In addition, a similar range of options can be provided for the torque transmitting elements of the other embodiments described above in terms of their mounting mode, so that the torque transmitting elements are separated from each other. the associated internal element or external element, at least at one of their ends and by providing an appropriate mounting means similar to those described above with regard to the embodiments shown in FIGS. 9 to 11.

  An end closure member 130 is locked by screws 131 on the cylindrical portion 122 of the outer member 110 and includes a wall portion 132, generally cylindrical, and a plate-like portion 133 extending radially. As can best be seen in FIG. 10, the cylindrical part 132 is provided with a pair of grooves 134 extending circumferentially and in which are housed the free ends of the wings of an insulating ring 136 with a U profile and serving when mounting the antenna.

  The wings 135 are retained in the groove 134 by an adhesive 137. An antenna 138 is fixed by an adhesive to the core 139 of the antenna mounting ring 136.

  The elements 129 for transmitting torque comprise a means 140, forming a strain gauge, which is mounted therein, as can best be seen in FIG. 9.

  An electric battery, communication and control means, such as those described in connection with the first embodiment, are mounted on the end closure element 130, in the space 141 delimited by this element.

  Appropriate connections are present between the strain gauges 140 and the communication and control means as well as the battery, as described above.

  The operating mode of the device described with reference to FIGS. 911 is identical to that described with regard to the first embodiment. The configuration of the torque transmission elements 129 makes the device more sensitive to low torques.

  If desired, the torque transmission element 129 can have a length, a width and a thickness different from those indicated above and their number can also be different depending on the torque that it is desired to transmit and detect.

  If desired, the embodiment described with reference to Figures 1-7 can be modified by providing an antenna mounting means similar to that shown at 136 in Figure 10 and by mounting the antenna on the inner side of this means, as shown in Figure 11. In addition, in the two embodiments, separate conductors may be present for the connection of the electric cell, and the device of Figure 1 may also be provided with a cover. closure similar to that of the embodiment of FIGS. 8-11 and the electric cell as well as the electronic means can be mounted in this cover. Furthermore, a soldered connection can be used in the antenna and in the transmission means.

  Any characteristic (s) of one or more embodiments, can (or can) be used in any of the embodiments, if appropriate, and can be modified if necessary .

  It is understood that the foregoing description

  has been given purely by way of non-limiting illustration and that variants or modifications may be made thereto within the framework of the present invention.

Claims (47)

  1. Torque indication device characterized in that it comprises: first and second parts connected so as to transmit mutually a torque; - torque transmission means connecting said first and second parts; - torque detection means arranged on said torque transmission means and reacting to the torque transmitted by said torque transmission means by producing a signal dependent on the transmitted torque; and - communication means comprising an electromagnetic radiation transmitter receiving said signal produced by said torque detection means and communicating an output signal dependent on said torque to reception means which supply an output signal in response to said transmitted torque.   2. Device according to claim 1, characterized in that it can rotate about an axis and in that the first part comprises a radially inner part relative to said axis and the second part comprises a part radially external to said axis, and the torque transmission means comprise at least one torque transmission element extending radially and circumferentially between said parts to transmit torque between the latter.   3. Device according to claim 2, characterized in that the outer part comprises a ring.   4. Device according to claim 2 or 3, characterized in that the inner part comprises a ring.   5. Device according to any one of claims 2 to 4, characterized in that the inner part is arranged coaxially inside the outer part, at least one torque transmission element extending between these parts.   6. Device according to any one of claims 2 to 5, characterized in that the element or each torque transmission element has, in the axial direction, a thickness which is less than its width in the circumferential direction.   7. Device according to any one of claims 2 to 4, characterized in that the element or each torque transmission element has, in the circumferential direction of the device, a thickness which is less than its width in the axial direction of these measures.   8. Device according to any one of claims 2 to 7, characterized in that the inner part and the outer part are further connected to each other by a plurality of connecting elements extending radially and axially and conferring axial stability on the torque indication device.   9. Device according to claim 8, characterized in that said connecting elements extending radially and axially have, in the circumferential direction of the device, a thickness which is less than their width in the axial direction of the latter.   10. Device according to any one of the preceding claims, characterized in that the first and second parts are connected to each other only by said torque transmission element and by said connecting elements, if these are present.   11. Device according to any one of claims 2 to 4, characterized in that the inner part comprises a hub on which the outer part is rotatably mounted, the inner part comprising a portion extending axially and arranged radially to the inside a portion, extending axially, of the outer part, and at least one torque transmission element extending between said portions.   12. Device according to claim 11, characterized in that the element or each torque transmission element has, in the axial direction of the device, a width which is greater than its thickness in the circumferential direction of the latter.   13. Device according to any one of claims 2 to 12, characterized in that the element or each torque transmission element is connected to the interior and exterior parts in a "built-in" manner or in a "simply supported" manner. ", or in a" simply supported "manner for a first amplitude of relative angular displacement between the interior and exterior elements and in a" recessed "manner for another amplitude of said displacement.   14. Device according to any one of claims 2 to 13, characterized in that it is provided with two diametrically opposed torque transmission elements.   15. Device according to any one of claims 2 to 14, characterized in that the inner part and the outer part are adapted to be connected to the first and second components so as to transmit a torque between the latter.   16. Device according to any one of the preceding claims, characterized in that the communication means are supplied by means forming an electric battery and supported by the device.   17. Device according to any one of the preceding claims, characterized in that the torque indication device is provided with a control means by which at least one of the torque measurements and a communication of said output signal are carried out. intermittently.   18. Device according to claim 17, characterized in that the frequency of measurement of the torque and / or of the communication of said output signal depends on the value of the torque.   19. Device according to claim 18, characterized in that, when the torque is less than a predetermined level, the frequency of measurement of said torque and / or of the communication of said output signal has a first value, while when the torque is equal to or greater than said predetermined level, said frequency has a higher value.   20. Device according to any one of the preceding claims, characterized in that the torque detection means comprise a means forming a strain gauge.   21. Device according to claim 20, characterized in that the strain gauge means comprises a bridge of strain gauges.   22. Device according to claim 21, characterized in that the bridge output signal is supplied to an amplifier.   23. Device according to claim 22, characterized in that the amplifier provides an output signal which is applied to a unipolar / bipolar converter so as to give a signal dependent on the direction of the torque which is transmitted.   24. Device according to claim 23, characterized in that the output signal of the unipolar / bipolar converter is applied to a microprocessor.   25. Device according to claim 24, characterized in that the microprocessor is an eight-bit microprocessor.   26. Device according to any one of the preceding claims, characterized in that the electromagnetic radiation is a radio frequency and is emitted by an antenna.   27. Device according to claim 26, characterized in that the transmitter is adapted to transmit one of the signals of the type with amplitude modulation and with frequency modulation.   28. Device according to claim 27, characterized in that the transmitter comprises a low power radio frequency oscillator which transmits an output signal to an appropriate reception means.   29. Device according to any one of claims 26 to 28, characterized in that the antenna is adapted to radiate the output signal in a uniform manner or circumferentially in a substantially uniform manner around the device.   30. Device according to any one of claims 26 to 29, characterized in that the antenna comprises a conductor which extends at least partially circumferentially around the device.   31. Device according to claim 30, characterized in that it comprises a circular circumferential surface oriented radially outward or inward and on which the antenna is mounted.   32. Device according to any one of claims 26 to 31, characterized in that the antenna is isolated from the outside by an appropriate insulating means.   33. Device according to any one of claims 26 to 32, characterized in that the antenna is mounted in the supply circuit by electric battery and is used to supply the electric current coming from the electric battery to the detection means of couple and the means of communication.   34. Device according to claim 33, characterized in that the antenna comprises two antenna parts, one of said parts constituting a conductor for supplying current with negative polarity from the electric cell and the other of said parts constituting a contact for a positive polarity current supply from the electric battery.   35. Device according to any one of the preceding claims, characterized in that it is provided with an opening extending radially and through which an electric cell is mounted on the device.   36. Device according to claim 35, characterized in that said opening is formed in said outer part, and the inner part is provided with a cavity, extending radially and aligned radially with said opening, in which is received a portion of the electric battery, and a second portion of the electric battery being received in the opening of the external part, a retaining means being provided for retaining the electric battery in the torque indication device.   37. Device according to any one of claims 26 to 34, characterized in that the antenna comprises a retaining means for an electric cell.   38. Device according to any one of claims 16 to 38, characterized in that the electric cell can be replaced radially.   39. Device according to any one of claims 11 to 38, characterized in that the device is provided with an end cover mounted on said outer part so as to rotate with the latter, the element or each transmission element of torque being disposed between the radially extending portion and the end cover.   40. Device according to any one of claims 39, characterized in that the electric battery and / or the communication means and / or the control means are housed inside the end cover.   41. Device according to any one of claims 16 to 40, characterized in that the control device is adapted to detect the battery voltage and the communication means is adapted to communicate a signal dependent on the battery voltage. so that one can check with the receiving means whether it is necessary to replace the battery.   42. Device according to any one of claims 16 to 41, characterized in that the control means initially switches over to the torque detection means and then switches over to the communication means.   43. Device according to any one of the preceding claims, characterized in that it is provided with at least one target serving to detect, for example by means of a photoelectric cell, the speed of rotation of the device.   44. Device according to claim 43, characterized in that it comprises means by which the speed of rotation of the device is integrated with the torque to provide an indication of the power.   45. Device according to any one of the preceding claims, characterized in that a torque-dependent display is provided in the device.   46. Device according to claim 45, characterized in that the display is carried out by a liquid crystal display means and the reception means reads the liquid crystal display means using a device appropriate scan signal and then displays a torque dependent output signal.   47. Device according to claim 46, characterized in that the liquid crystal display means displays an output signal in the form of an appropriate barcode.