EP0194206B1 - Device displaying and controlling the traction applied to the extension arm of an orthopaedic table - Google Patents

Device displaying and controlling the traction applied to the extension arm of an orthopaedic table Download PDF

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Publication number
EP0194206B1
EP0194206B1 EP19860400481 EP86400481A EP0194206B1 EP 0194206 B1 EP0194206 B1 EP 0194206B1 EP 19860400481 EP19860400481 EP 19860400481 EP 86400481 A EP86400481 A EP 86400481A EP 0194206 B1 EP0194206 B1 EP 0194206B1
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EP
European Patent Office
Prior art keywords
force
screw
rotation
recorded
electric motor
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Expired
Application number
EP19860400481
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German (de)
French (fr)
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EP0194206A1 (en
Inventor
Georges Gazuit
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MARZET-AUBRY SA
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MARZET-AUBRY SA
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Publication of EP0194206A1 publication Critical patent/EP0194206A1/en
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61H—PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY
    • A61H1/00—Apparatus for passive exercising; Vibrating apparatus; Chiropractic devices, e.g. body impacting devices, external devices for briefly extending or aligning unbroken bones
    • A61H1/02—Stretching or bending or torsioning apparatus for exercising
    • A61H1/0218—Drawing-out devices

Definitions

  • the present invention relates to a device for displaying and controlling the force applied to the extension arm of an orthopedic table, allowing the direct reading of the force applied to the extension arm and the constant maintenance of this force whatever the angular position in space of this extension arm, or the dynamic maneuver causing the angular modification of the position of the arm.
  • Orthopedic tables are generally made up of a horizontal or tilting table on which the patient rests, and extendable articulated arms on which his feet are fixed.
  • the articulated arms generally consist of a deformable parallelogram system allowing angular modification in the horizontal and vertical planes.
  • the extension is ensured by a telescopic tube maneuvered by a screw-nut system and a crank.
  • this device has drawbacks which reside in its exclusively manual function, and in the absence of control of the intensity of the force which leads to manual adjustment remaining entirely subjective. Furthermore, there is a variation in the intensity of the applied force, more or less, during the angular movement of the arm in the horizontal or vertical planes, this being due to the fact that the axis of articulation of the Deformable parallelogram mechanical device does not coincide with the patient's hip joint axis, and it is difficult to constantly readjust the applied force. Furthermore, the implementation of a fully automatic and preprogrammed system is costly and does not allow the practitioner to control and measure the rate of progression of the effort exerted. A similar system, although based on a cable and pulley traction device essentially different from that of the invention, is illustrated for example in FR-A-2 367 483.
  • the object of the device according to the invention is to remedy these drawbacks and to allow operation with manual and automatic phases.
  • a device for displaying and controlling the force applied to the extension arm of an orthopedic table said arm being moved in extension or retraction by a telescopic tube actuated by a screw system and nut, the screws being able to be rotated manually by means of an operating member, characterized in that it comprises a force-sensing member interposed between the control screw of the tube and a fixed point of the arm, such as the housing (17) of the same device, said sensor member being connected to a means for displaying the force F recorded by the sensor member, in that it comprises an electric motor allowing the automatic driving of the screw in rotation and switching means to allow the screw to be driven either manually from said operating member, or automatically from an electric motor and in that it further comprises an electronic circuit ensuring, in position of automatic operation, the comparison of two forces, one of which is the force F recorded by the sensor member and the other is a chosen reference force Fo, obtained beforehand in a position for manual control of the screw by setting memory of the force recorded by the sensor member before switching to the automatic
  • the electronic circuit is connected to a means for displaying a reference force Fo and to a means for displaying the real force F recorded by the real force sensor member.
  • the electronic circuit comprises a comparator, one of the inputs of which is connected by an amplifier to the force sensor member and whose other input is connected to an adjustment potentiometer, said comparator having its output connected on the one hand to a meter and on the other hand to the bases of two transistors which respectively supply two relay coils controlling the selective supply of the electric motor for its rotation in one direction or the other, when the electric motor is put into service by a switch.
  • the circuit advantageously further comprises two transistors oscillating at predetermined frequencies by an adjustment and connected on optocouplers giving a breakdown of the voltage which is applied (in CD and EF) on the base-emitter space of the transistors for modify the reaction time of these transistors.
  • the device comprises a housing on which is fixed, at one of its ends an element of the telescopic tube and in which is rotatably mounted one of the ends of the worm which is connected to a inner sleeve integral in rotation with an outer sleeve but mounted to slide axially relative to the latter, and connected by rolling stops to one end of the force sensor member, the other end of which is fixed to the housing, said outer sleeve being rotatably mounted in the housing and integral in rotation with a pinion mounted axially sliding on said outer sleeve in order to selectively mesh with a pinion driven in rotation by the electric motor and with a pinion driven in rotation by a manual control member.
  • the function of supplying the initial traction force to the desired traction force remains manual, but the function of conservation of the desired traction force is made automatic.
  • a sensor measures the intensity of the force which is displayed in direct reading, thus allowing objective adjustment of the desired force, while helping to ensure automatic maintenance of the desired force.
  • the intensity of the force measured by the sensor is controlled by a predetermined reference force so that the control motor of the screw-nut system of the telescopic tube of the extension arm is biased in a direction of rotation or in the other according to the comparison of the force indicated by the sensor and the predetermined force, which was chosen beforehand by the operator.
  • the system automatically regulating the length of the telescopic tube to the length necessary to maintain the force. , and thus compensates for the variation in parallax between the articulation of the extension arm and the articulation of the patient during the operation of the extension arm.
  • FIG. 1 shows a device 10 for displaying and controlling the force applied to the extension arm of an orthopedic table, said arm comprising a telescopic tube 2, 2a composed of an external element 2 and d an internal element 2a actuated by an endless screw 3 which is engaged in a nut 8 integral with the internal part 2a of the telescopic tube which is connected to a part 9 fixed to the patient's foot on which a traction force F is exerted
  • At one end of the endless screw 3 is fixed one of the ends of a force-sensing member 1 or strain gauge, the other end of which is fixed to a fixed point of the extension arm, such that the housing 17 of the control device 10.
  • the force sensor member 1 transmits to a recording member 6 information corresponding to the intensity of the force F.
  • the recording member 6 is connected on the one hand to a first display member 11 of the real force and on the other hand to an electronic circuit 7.
  • the device 10 comprises a control member 5 making it possible to store a reference force value which can be displayed on a second display member 12.
  • the pressure sensor member 1 transmits at any time to the recording member 6 the intensity of the force F acting on the patient's limb.
  • the practitioner can manually pull the patient's leg until the desired force is obtained.
  • the actual force exerted on the patient's leg is displayed at all times on the display member 11 and the practitioner can constantly know the importance of the force exerted.
  • the operator can permanently control and dose the force exerted as well as the speed with which an effort must be gradually exerted.
  • the device according to the invention is placed in an automatic operating position and an automatic control then makes it possible to guarantee that, whatever the patient's movements, the traction force chosen by the practitioner will continue to be exercised automatically without modification and without manual intervention.
  • the value of the real force exerted, which is recorded at this instant in the recording member 6 is displayed in the display member 11, is recorded in the second recording member 5 and displayed on the second display member 12.
  • the pinion 116 is disengaged so as no longer to be engaged with the pinion 115 secured to the shaft 43 driven by the flywheel 44, and a pinion 16, integral in rotation with the extension of the worm screw 3 is engaged with a pinion 15 integral with the output shaft of an electric motor 4 which can be rotated in one direction or the other from conductors 13, 14 of the motor 4 power control.
  • the electronic circuit 7 comprises a comparator circuit to which are applied during the automatic operation of the device, on the one hand a signal emitted by the recording member 5 and representing the value of a reference force corresponding to the value of the force exerted at the level of the sensor 1 when switching from manual operation to automatic operation and on the other hand, a signal emitted by the recording device 6 and representing the value of the real force exerted at the instant considered at the level of sensor 1.
  • the pressure sensor member 1 stores in memory 6 the intensity of the force F acting on the patient's limb. Said intensity of the force which appears on the display member 11 is also transmitted to the comparator circuit of the electronic circuit 7, in order to be compared with the value of the reference force stored in memory 5 and displayed in the member 12 display of the reference force. According to the imbalance recorded between the real force and the reference force, the circuit 7 transmits information to the supply circuit of the motor 4 by the line 13 or 14 so that the motor 4 is driven in rotation in one direction or in the other.
  • the motor 4 rotates, by the pinions 15 and 16, the screw 3 which, by acting through the nut 8, causes the telescopic tube 2, 2a to shorten or lengthen.
  • the actual force exerted at point 9 on the patient's limb is increased or decreased.
  • the electronic circuit 7 gives information leading to a rotation of the motor 4 causing a rotation of the control screw 3 in one direction or the other such that the length L is increased or reduced in the direction where the real force tends to become equal to the reference force Fo.
  • FIG. 2 schematically shows the mechanical design of an orthopedic traction device equipped with an electronic tension controller according to the invention.
  • the actual pulling device comprises a support tube 2 which can itself be mounted on another orientable support member, not shown in FIG. 2, and a tube 2a telescopically sliding inside the support tube 2.
  • a control screw 3 is engaged in a nut 8 secured to the inner tube 2a and is extended by a non-threaded part which is engaged in a bearing 33 fitted at the end of the outer tube 2 opposite the point 9 of application of the tensile force on the patient's limb.
  • the inner tube 2a which carries the nut 8 and surrounds the screw 3 over part of its length, is moved axially in one direction or the other by sliding in the outer tube 2 to modify the position of point 9 and consequently the traction force.
  • the tension control and display device 10 comprises a molded case 17 which fits onto the end of the external support tube 2, around the bearing 33 inside which the non-threaded end of the screw 3 journals. .
  • a drive shaft for the screw 3 is mounted on a ball bearing 30 inside a non-rotating frame 127 which receives the axial forces exerted on the screw 3 and supports the end 23 of a strain gauge 1 , or an equivalent force-measuring device, the other end of which is fixed to the housing 17 of the device 10.
  • a pinion 115 is mounted on a sleeve 126 coaxial with the shaft 43 of a flywheel 44, to be driven in rotation with the shaft 43.
  • the sleeve 126 is connected by a member d adaptation 117 to one end of a lever 37 which can pivot around a fixed point 137.
  • a first position of the lever 37 the pinion 115 is engaged with a pinion 16 mounted on a non-threaded part of the screw 3.
  • the screw 3 can be rotated by the flywheel 44.
  • a second position of the lever 37 which corresponds to the position shown in FIG. 4, the pinion 115 is no longer engaged with the pinion 16 and a contact 107 makes it possible to energize a gear motor 4 which then controls the rotation of the screw 3 by means of a set of pinions 15, 16.
  • the electric motor 4 is controlled by electronic circuits 7 incorporated in the housing 17 and the device is set to the automatic display voltage maintenance position.
  • the members 11, 12 for displaying the real force applied to the patient's limb and the reference force chosen when switching from the manual position to the automatic position can be arranged for example on a side face of the housing 17, or on the upper face of the housing 17.
  • the control device makes it possible to carry out a direct reading of the force exerted during the entire manual phase during which traction is carried out on the patient's leg up to the desired force.
  • the handle 37 Once the traction force has been reached, the handle 37 being placed in the automatic position, the electronic controller is in action and the traction force exerted is controlled to remain constant even if the position of the patient undergoes certain modifications.
  • the display members 11, 12 make it possible to read at all times the reference value and the real measured force which is adapted using the control device to be brought back to the reference value.
  • FIG. 5 shows a mode of particular embodiment of the mechanical arrangement of a control device according to the invention.
  • the end 18 of the fixed element 2 of the telescopic tube 2, 2a is fitted and fixed by locking screws 19 on the housing 17 made of cast aluminum.
  • the pressure sensor member 1 Inside the housing 17 is arranged the pressure sensor member 1, one end of which is fixed by a pin 20 in two housings 21, 21a has a washer 22 secured to the housing.
  • the sensor member 1 is provided with a rod 23 which has a head 23a resting against two thrust ball bearings 24, 24a separated by a spacer 25 and kept tight by a nut 26 screwed onto the threaded part 23b of the rod 23, the stops 24, 24a thus being made integral with an inner sleeve 27 integral in rotation with an outer sleeve 28 by a key 29 allowing the axial sliding of the sleeve 27 in the sleeve 28.
  • the outer sleeve 28 is rotatably mounted by means of a ball bearing 30 and a needle bearing 31 in the housing 17.
  • the inner sleeve 27 is made integral in rotation with the extension 3a of the screw 3 by a key 32, said screw 3 being engaged in a bearing 33 fitted at one of the ends of the fixed element 2 of the telescopic tube 2, 2a.
  • a pinion 34 which is integral in rotation with said sleeve in particular by a key, said pinion being subjected to the action of a helical spring 35 bearing against a shoulder of the sleeve 28 and being capable of sliding against the action of the spring under the action of a finger 36 of a selector rotatably mounted on one of the side covers 38, 38a closing the housing 17.
  • the selector 36 is actuated from the outside by a lever 37 (fig. 6).
  • the pinion 34 is capable of meshing either with a pinion 39 keyed onto the output shaft 40 of the motor 4 fixed inside the housing 17 by means of a fixing bracket 41, or with a pinion 42 fixed to the end of a shaft 43 rotatably mounted in the housing 17 and provided at one of its ends with an operating wheel 44.
  • the electric control circuit for controlling the motor 4 or motor-reducer and the electronic circuit 7 for measuring the intensity of the force.
  • FIG. 7 A possible embodiment of the electronic circuit 7 is shown in FIG. 7.
  • the force sensor or gauge member 1 is connected via an amplifier 45 and a resistor 71, connected in series to the output of the amplifier 45, to one of the inputs 46 of a comparator circuit 47, the other input 48 of which is connected, via a resistor 72, to an adjustment potentiometer 49.
  • Resistors 75, 76, 77 allow the parameters of the comparator circuit 47 to be adjusted.
  • Two diodes 73, 74 are furthermore mounted in parallel between the inputs 46 and 48 of the comparator 47, the cathode of each of the diodes being connected to the anode of the other diode .
  • the output 50 of the comparator 47 is connected, via the series circuit composed of a zener diode 78 and a resistor 79, to the base of a transistor 51, the collector of which is connected in series with a contact 5 2 of a second relay 54 and with the coil 8, of a first relay 53, itself mounted in parallel with a protective diode 82.
  • the output of the comparator 47 is connected, via the series circuit composed of a zener diode 80 and a resistor 81, at the base of a second transistor 52, of a type complementary to that of transistor 51 and the collector of which is connected in series with a contact 5 1 of the first relay 53 and with the coil B 2 of the second relay 54, itself mounted in parallel with a protection diode 83.
  • the actual force applied by means of the screw 3 to the patient's leg is determined by the force sensor member 1 which delivers at the output of the amplifier 45 a voltage proportional to the actual force exerted. This voltage is applied to the first input 46 of the comparator 47, the second input of which is connected to the potentiometer 49.
  • the voltage supplied on the input 46 of the comparator represents the real force gradually exerted manually on the patient's leg.
  • This voltage makes it possible to display a value of actual force exerted on a display member, such as the display member 11 of FIG. 1.
  • the potentiometer 49 is set so as to indicate a zero value on the high impedance voltmeter or vumeter 55 placed between the comparator output 47 and the potentiometer cursor 49.
  • the vumeter 55 is at zero, there is a balance of the voltages on the inputs 46 and 48 of comparator 47. This means that the reference voltage has been chosen equal to the value of the real force reached at the end of the manual phase.
  • the flywheel 44 After switching to automatic operation using the handle 37 of Figure 6, the flywheel 44 is disengaged, the motor 4 is engaged with the screw 3, and the switch 92 is closed.
  • the force sensor member 1 delivers a new voltage such that the balance between the two voltages at the terminals of the meter 55 is broken.
  • the new value of the voltage on the input 46 of the comparator 47 modifies the output voltage of the comparator 47 which provides a voltage by tilting either on the transistor 51 or on the transistor 52, thus causing a supply of the motor 4 by the relay 53 or the relay 54 and consequently a rotation of the motor in one direction or the other.
  • the direction of rotation of the motor is such that the voltage recorded by the gauge 1 tends to return to its initial position such that the meter 55 returns to its equilibrium position indicating zero.
  • an electrical device for adjusting the reaction speed of the transistors 51 and 52 of FIG. 7 is used.
  • Transistors 56, 57 the collectors of which are connected by polarization resistors 89, 90 to the + V supply line, oscillate at predetermined frequencies by a circuit comprising a potentiometer 58 and capacitors 61, 62.
  • the capacitor 61 is connected between the collector of transistor 57 and the collector of transistor 56 while the capacitor 62 is connected between the base of transistor 57 and the collector of transistor 56.
  • Potentiometer 58 mounted between the bases of transistors 56, 57 has its cursor connected to a divider bridge formed by resistors 87, 88 connected between supply + V and earth.
  • the collector of transistor 57 is connected to two optocouplers 59, 60 connected in series with a resistor 91.
  • the optocouplers carry out a voltage cutting between on the one hand the terminals c and d and on the other hand the terminals e and f of the circuit of FIG. 7, which modifies the reaction times of the transistors 51 and 52.
  • the potentiometer 58 allows manual adjustment of the reaction speed of the transistors 51, 52.

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  • Pain & Pain Management (AREA)
  • Physical Education & Sports Medicine (AREA)
  • Rehabilitation Therapy (AREA)
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Description

La présente invention a pour objet un dispositif d'affichage et de contrôle de la force appliquée sur le bras d'extension d'une table orthopédique, permettant la lecture directe de la force appliquée sur le bras d'extension et le maintien constant de cette force quelle que soit la position angulaire dans l'espace de ce bras d'extension, ou la manoeuvre dynamique entraînant la modification angulaire de la position du bras.The present invention relates to a device for displaying and controlling the force applied to the extension arm of an orthopedic table, allowing the direct reading of the force applied to the extension arm and the constant maintenance of this force whatever the angular position in space of this extension arm, or the dynamic maneuver causing the angular modification of the position of the arm.

Les tables d'orthopédie sont généralement constituées d'une table horizontale ou inclinable sur laquelle repose le patient, et de bras articulés extensibles sur lesquels sont fixés ses pieds. Les bras articulés sont généralement constitués d'un système à parallélogramme déformable permettant une modification angulaire dans les plans horizontaux et verticaux.Orthopedic tables are generally made up of a horizontal or tilting table on which the patient rests, and extendable articulated arms on which his feet are fixed. The articulated arms generally consist of a deformable parallelogram system allowing angular modification in the horizontal and vertical planes.

L'extension est assurée par un tube télescopique manoeuvré par un système vis-écrou et une manivelle.The extension is ensured by a telescopic tube maneuvered by a screw-nut system and a crank.

Toutefois ce dispositif présente des inconvénients qui résident dans sa fonction exclusivement manuelle, et dans l'absence de contrôle de l'intensité de la force qui conduit à un réglage manuel restant entièrement subjectif. Par ailleurs, il se produit une variation de l'intensité de la force appliquée, en plus ou en moins, lors de la manceuvre angulaire du bras dans les plans horizontaux ou verticaux, cela étant dû au fait que l'axe d'articulation du dispositif mécanique à parallélogramme déformable ne coïncide pas avec l'axe d'articulation de la hanche du patient, et il est difficile de réajuster constamment la force appliquée. Par ailleurs, la mise en œuvre d'un système entièrement automatique et préprogrammé est coûteux et ne permet pas au praticien de contrôler et doser le rythme de la progression de l'effort exercé. Un système similaire, bien que basé sur un dispositif de traction à câble et poulie essentiellement différent de celui de l'invention, est illustré par exemple dans FR-A-2 367 483.However, this device has drawbacks which reside in its exclusively manual function, and in the absence of control of the intensity of the force which leads to manual adjustment remaining entirely subjective. Furthermore, there is a variation in the intensity of the applied force, more or less, during the angular movement of the arm in the horizontal or vertical planes, this being due to the fact that the axis of articulation of the Deformable parallelogram mechanical device does not coincide with the patient's hip joint axis, and it is difficult to constantly readjust the applied force. Furthermore, the implementation of a fully automatic and preprogrammed system is costly and does not allow the practitioner to control and measure the rate of progression of the effort exerted. A similar system, although based on a cable and pulley traction device essentially different from that of the invention, is illustrated for example in FR-A-2 367 483.

Le dispositif suivant l'invention a pour objet de remédier à ces inconvénients et de permettre un fonctionnement avec des phases manuelle et automatique.The object of the device according to the invention is to remedy these drawbacks and to allow operation with manual and automatic phases.

Ces buts sont atteints grâce à un dispositif d'affichage et de contrôle de la force appliquée sur le bras d'extension d'une table orthopédique, ledit bras étant déplacé en extension ou en rétraction par un tube télescopique actionné par un système à vis et écrou, les vis pouvant être entraînées en rotation de façon manuelle à l'aide d'un organe de manoeuvre, caractérisé en ce qu'il comporte un organe capteur de force interposé entre la vis de commande du tube et un point fixe du bras, tel que le boîtier (17) du même dispositif, ledit organe capteur étant relié à un moyen d'affichage de la force F enregistrée par l'organe capteur, en ce qu'il comprend un moteur électrique permettant l'entraînement automatique de la vis en rotation et des moyens de commutation pour permettre l'entraînement de la vis soit manuellement à partir dudit organe de manoeuvre, soit de façon automatique à partir d'un moteur électrique et en ce qu'il comprend en outre un circuit électronique assurant, en position de fonctionnement automatique, la comparaison de deux forces dont l'une est la force F enregistrée par l'organe capteur et l'autre est une force Fo de référence choisie, obtenue préalablement dans une position de commande manuelle de la vis par la mise en mémoire de la force enregistrée par l'organe capteur avant commutation sur la position de fonctionnement automatique, ledit circuit électronique réagissant en position de fonctionnement automatique à toute variation de la force F enregistrée par l'organe capteur par rapport à la force de référence Fo et émettant des impulsions qui sont transmises au moteur électrique pour entraîner en rotation la vis sans fin dans un sens ou dans l'autre afin de provoquer une variation de longueur L du tube télescopique suivant le sens de déséquilibre entre les deux forces F et Fo de telle manière que la force F enregistrée soit ramenée à la valeur de la force de référence Fo.These aims are achieved by means of a device for displaying and controlling the force applied to the extension arm of an orthopedic table, said arm being moved in extension or retraction by a telescopic tube actuated by a screw system and nut, the screws being able to be rotated manually by means of an operating member, characterized in that it comprises a force-sensing member interposed between the control screw of the tube and a fixed point of the arm, such as the housing (17) of the same device, said sensor member being connected to a means for displaying the force F recorded by the sensor member, in that it comprises an electric motor allowing the automatic driving of the screw in rotation and switching means to allow the screw to be driven either manually from said operating member, or automatically from an electric motor and in that it further comprises an electronic circuit ensuring, in position of automatic operation, the comparison of two forces, one of which is the force F recorded by the sensor member and the other is a chosen reference force Fo, obtained beforehand in a position for manual control of the screw by setting memory of the force recorded by the sensor member before switching to the automatic operating position, said electronic circuit reacting in the automatic operating position to any variation in the force F recorded by the sensor member relative to the reference force Fo and emitting pulses which are transmitted to the electric motor to rotate the worm in one direction or the other in order to cause a variation in length L of the telescopic tube according to the direction of imbalance between the two forces F and Fo such so that the force F recorded is brought back to the value of the reference force Fo.

Avantageusement, le circuit électronique est relié à un moyen d'affichage d'une force de référence Fo et à un moyen d'affichage de la force réelle F enregistrée par l'organe capteur de force réelle.Advantageously, the electronic circuit is connected to a means for displaying a reference force Fo and to a means for displaying the real force F recorded by the real force sensor member.

Selon une caractéristique particulière de l'invention, le circuit- électronique comprend un comparateur dont l'une des entrées est reliée par un amplificateur à l'organe capteur de force et dont l'autre entrée est reliée à un potentiomètre de réglage, ledit comparateur ayant sa sortie reliée d'une part à un vumètre et d'autre part aux bases de deux transistors qui alimentent respectivement deux bobines de relais commandant l'alimentation sélective du moteur électrique pour sa rotation dans un sens ou dans l'autre, lorsque le moteur électrique est mis en service par un commutateur.According to a particular characteristic of the invention, the electronic circuit comprises a comparator, one of the inputs of which is connected by an amplifier to the force sensor member and whose other input is connected to an adjustment potentiometer, said comparator having its output connected on the one hand to a meter and on the other hand to the bases of two transistors which respectively supply two relay coils controlling the selective supply of the electric motor for its rotation in one direction or the other, when the electric motor is put into service by a switch.

Dans ce cas, le circuit comprend avantageusement en outre deux transistors oscillant à des fréquences prédéterminées par un réglage et connectés sur des optocoupleurs donnant un découpage de la tension qui est appliquée (en CD et EF) sur l'espace base-émetteur des transistors pour modifier le temps de réaction de ces transistors.In this case, the circuit advantageously further comprises two transistors oscillating at predetermined frequencies by an adjustment and connected on optocouplers giving a breakdown of the voltage which is applied (in CD and EF) on the base-emitter space of the transistors for modify the reaction time of these transistors.

Selon un mode particulier de réalisation, le dispositif comprend un boîtier sur lequel est fixé, à l'une de ses extrémités un élément du tube télescopique et dans lequel est montée rotative l'une des extrémités de la vis sans fin qui est reliée à un manchon intérieur solidaire en rotation d'un manchon extérieur mais monté coulissant axialement par rapport à celui-ci, et relié par des butées à roulement à l'une des extrémités de l'organe capteur de force dont l'autre extrémité est fixée sur le boîtier, ledit manchon extérieur étant monté rotatif dans le boîtier et solidaire en rotation d'un pignon monté coulissant axialement sur ledit manchon extérieur afin d'engrener sélectivement avec un pignon entraîné en rotation par le moteur électrique et avec un pignon entraîné en rotation par un organe de commande manuelle.According to a particular embodiment, the device comprises a housing on which is fixed, at one of its ends an element of the telescopic tube and in which is rotatably mounted one of the ends of the worm which is connected to a inner sleeve integral in rotation with an outer sleeve but mounted to slide axially relative to the latter, and connected by rolling stops to one end of the force sensor member, the other end of which is fixed to the housing, said outer sleeve being rotatably mounted in the housing and integral in rotation with a pinion mounted axially sliding on said outer sleeve in order to selectively mesh with a pinion driven in rotation by the electric motor and with a pinion driven in rotation by a manual control member.

Avec le dispositif suivant l'invention la fonction d'amenée de la force de traction initiale à la force de traction voulue reste manuelle, mais la fonction de conservation de la force de traction voulue est rendue automatique. Un capteur mesure l'intensité de la force qui est affichée en lecture directe permettant ainsi un réglage objectif de la force désirée, tout en contribuant à assurer ensuite un maintien automatique de la force désirée.With the device according to the invention, the function of supplying the initial traction force to the desired traction force remains manual, but the function of conservation of the desired traction force is made automatic. A sensor measures the intensity of the force which is displayed in direct reading, thus allowing objective adjustment of the desired force, while helping to ensure automatic maintenance of the desired force.

Selon l'invention, l'intensité de la force mesurée par le capteur est asservie à une force de référence prédéterminée de telle façon que le moteur de commande du système vis-écrou du tube télescopique du bras d'extension est sollicité dans un sens de rotation ou dans l'autre suivant la comparaison de la force indiquée par le capteur et la force prédéterminée, qui a été choisie au préalable par l'opérateur.According to the invention, the intensity of the force measured by the sensor is controlled by a predetermined reference force so that the control motor of the screw-nut system of the telescopic tube of the extension arm is biased in a direction of rotation or in the other according to the comparison of the force indicated by the sensor and the predetermined force, which was chosen beforehand by the operator.

De cette façon, dans la phase de fonctionnement automatique, l'intensité de la force appliquée reste constante quellè que soit la manoeuvre du bras dans l'espace, le système régulant automatiquement la longueur du tube télescopique à la longueur nécessaire au maintien de la force, et rattrape ainsi la variation de parallaxe entre l'articulation du bras d'extension et l'articulation du patient pendant la manoeuvre du bras d'extension.In this way, in the automatic operating phase, the intensity of the applied force remains constant regardless of the operation of the arm in space, the system automatically regulating the length of the telescopic tube to the length necessary to maintain the force. , and thus compensates for the variation in parallax between the articulation of the extension arm and the articulation of the patient during the operation of the extension arm.

D'autres caractéristiques et avantages de l'invention seront mieux compris à la lecture de la description qui va suivre de plusieurs modes de réalisation et en se référant aux dessins annexés, sur lesquels :

  • - la figure 1 est une vue schématique de principe du dispositif d'affichage et de contrôle de force selon l'invention,
  • - la figure 2 est une vue simplifiée en coupe longitudinale de l'ensemble mécanique d'un mode de réalisation du dispositif selon l'invention,
  • - la figure 3 est une vue en coupe selon la ligne 111-111 de la figure 2,
  • - la figure 4 est une vue en coupe selon la ligne IV-IV de la figure 3,
  • - la figure 5 est une vue détaillée en coupe longitudinale d'un mode particulier de réalisation de l'ensemble mécanique du dispositif selon l'invention,
  • - la figure 6 est une vue en coupe transversale du boîtier du dispositif de la figure 5,
  • - la figure 7 représente le schéma d'un circuit électronique d'asservissement d'un moteur de commande utilisable dans le cadre de la présente invention, et
  • - la figure 8 représente le schéma d'une variante de réalisation du circuit électronique de la figure 7.
Other characteristics and advantages of the invention will be better understood on reading the following description of several embodiments and with reference to the appended drawings, in which:
  • FIG. 1 is a schematic view of the principle of the display and force control device according to the invention,
  • FIG. 2 is a simplified view in longitudinal section of the mechanical assembly of an embodiment of the device according to the invention,
  • FIG. 3 is a sectional view along line 111-111 of FIG. 2,
  • FIG. 4 is a sectional view along the line IV-IV of FIG. 3,
  • FIG. 5 is a detailed view in longitudinal section of a particular embodiment of the mechanical assembly of the device according to the invention,
  • FIG. 6 is a cross-sectional view of the housing of the device in FIG. 5,
  • FIG. 7 represents the diagram of an electronic control circuit for a control motor usable in the context of the present invention, and
  • FIG. 8 represents the diagram of an alternative embodiment of the electronic circuit of FIG. 7.

On a représenté sur la figure 1 un dispositif 10 d'affichage et de contrôle de la force appliquée sur le bras d'extension d'une table orthopédique, ledit bras comportant un tube télescopique 2, 2a composé d'un élément extérieur 2 et d'un élément intérieur 2a actionné par une vis sans fin 3 qui est engagée dans un écrou 8 solidaire de la partie intérieure 2a du tube télescopique qui est reliée à une pièce 9 fixée au pied du patient sur lequel s'exerce une force de traction F. A l'une des extrémités de la vis sans fin 3 est fixée l'une des extrémités d'un organe capteur de force 1 ou jauge de contrainte dont l'autre extrémité est fixée sur un point fixe du bras d'extension, tel que le boîtier 17 du dispositif de contrôle 10.FIG. 1 shows a device 10 for displaying and controlling the force applied to the extension arm of an orthopedic table, said arm comprising a telescopic tube 2, 2a composed of an external element 2 and d an internal element 2a actuated by an endless screw 3 which is engaged in a nut 8 integral with the internal part 2a of the telescopic tube which is connected to a part 9 fixed to the patient's foot on which a traction force F is exerted At one end of the endless screw 3 is fixed one of the ends of a force-sensing member 1 or strain gauge, the other end of which is fixed to a fixed point of the extension arm, such that the housing 17 of the control device 10.

L'organe capteur de force 1 transmet à un organe d'enregistrement 6 une information correspondant à l'intensité de la force F. L'organe d'enregistrement 6 est relié d'une part à un premier organe d'affichage 11 de la force réelle et d'autre part à un circuit électronique 7. Par ailleurs, le dispositif 10 comprend un organe de contrôle 5 permettant de mettre en mémoire une valeur de force de référence qui peut être affichée sur un second organe d'affichage 12.The force sensor member 1 transmits to a recording member 6 information corresponding to the intensity of the force F. The recording member 6 is connected on the one hand to a first display member 11 of the real force and on the other hand to an electronic circuit 7. Furthermore, the device 10 comprises a control member 5 making it possible to store a reference force value which can be displayed on a second display member 12.

L'organe capteur de pression 1 transmet à tout instant à l'organe d'enregistrement 6 l'intensité de la force F agissant sur le membre du patient.The pressure sensor member 1 transmits at any time to the recording member 6 the intensity of the force F acting on the patient's limb.

Dans un premier temps, lorsque le dispositif est placé dans une position de fonctionnement en manuel par un organe de commutation, non représenté sur la figure 1, un pignon 116 calé sur un prolongement de la vis sans fin 3 engrène sur un pignon 115 monté sur un arbre 43 entraîné en rotation par un volant extérieur de manceuvre 44.At first, when the device is placed in a manual operating position by a switching member, not shown in FIG. 1, a pinion 116 wedged on an extension of the worm gear 3 meshes on a pinion 115 mounted on a shaft 43 rotated by an external maneuvering wheel 44.

De cette manière, le praticien peut procéder -manuellement à la traction sur la jambe du patient jusqu'à obtenir la force désirée. La force réelle exercée sur la jambe du patient est à tout instant affichée sur l'organe d'affichage 11 et le praticien peut constamment connaître l'importance de la force exercée. Parallèlement, du fait même de l'action manuelle exercée au moyen du volant 44, l'opérateur peut en permanence contrôler et doser l'effort exercé ainsi que la rapidité avec laquelle un effort doit être progressivement exercé.In this way, the practitioner can manually pull the patient's leg until the desired force is obtained. The actual force exerted on the patient's leg is displayed at all times on the display member 11 and the practitioner can constantly know the importance of the force exerted. At the same time, by the very fact of the manual action exerted by means of the handwheel 44, the operator can permanently control and dose the force exerted as well as the speed with which an effort must be gradually exerted.

Une fois que l'effort de traction souhaité a été atteint, le dispositif selon l'invention est placé sur une position de fonctionnement automatique et un contrôle automatique permet ensuite de garantir que, quels que soient les mouvements du patient, l'effort de traction choisi par le praticien continuera d'être exercé automatiquement sans modification et sans intervention manuelle.Once the desired traction force has been reached, the device according to the invention is placed in an automatic operating position and an automatic control then makes it possible to guarantee that, whatever the patient's movements, the traction force chosen by the practitioner will continue to be exercised automatically without modification and without manual intervention.

Lors du passage en fonctionnement automatique deux opérations sont effectuées simultanément. D'une part, la valeur de la force réelle exercée, qui est enregistrée à cet instant dans l'organe d'enregistrement 6 est affichée dans l'organe d'affichage 11, est enregistrée dans le second organe d'enregistrement 5 et affichée sur le second organe d'affichage 12. D'autre part, le pignon 116 est débrayé pour ne plus être en prise avec le pignon 115 solidaire de l'arbre 43 entraîné par le volant 44, et un pignon 16, solidaire en rotation du prolongement de la vis sans fin 3 est mis en prise avec un pignon 15 solidaire de l'arbre de sortie d'un moteur électrique 4 qui peut être entraîné en rotation dans un sens ou dans l'autre à partir de conducteurs 13, 14 de commande d'alimentation du moteur 4.When switching to automatic operation two operations are performed simultaneously. On the one hand, the value of the real force exerted, which is recorded at this instant in the recording member 6 is displayed in the display member 11, is recorded in the second recording member 5 and displayed on the second display member 12. On the other hand, the pinion 116 is disengaged so as no longer to be engaged with the pinion 115 secured to the shaft 43 driven by the flywheel 44, and a pinion 16, integral in rotation with the extension of the worm screw 3 is engaged with a pinion 15 integral with the output shaft of an electric motor 4 which can be rotated in one direction or the other from conductors 13, 14 of the motor 4 power control.

Le circuit électronique 7 comprend un circuit comparateur auquel sont appliqués lors du fonctionnement du dispositif en automatique, d'une part un signal émis par l'organe d'enregistrement 5 et représentant la valeur d'une force de référence correspondant à la valeur de la force exercée au niveau du capteur 1 lors de la commutation du fonctionnement manuel au fonctionnement automatique et d'autre part, un signal émis par l'organe d'enregistrement 6 et représentant la valeur de la force réelle exercée à l'instant considéré au niveau du capteur 1.The electronic circuit 7 comprises a comparator circuit to which are applied during the automatic operation of the device, on the one hand a signal emitted by the recording member 5 and representing the value of a reference force corresponding to the value of the force exerted at the level of the sensor 1 when switching from manual operation to automatic operation and on the other hand, a signal emitted by the recording device 6 and representing the value of the real force exerted at the instant considered at the level of sensor 1.

A tout instant, lors du fonctionnement en automatique, l'organe capteur de pression 1 enregistre dans la mémoire 6 l'intensité de la force F agissant sur le membre du patient. Ladite intensité de la force qui apparaît sur l'organe d'affichage 11 est également transmise au circuit comparateur du circuit électronique 7, afin d'être comparée avec la valeur de la force de référence mémorisée dans la mémoire 5 et affichée dans l'organe 12 d'affichage de la force de référence. Suivant le déséquilibre enregistré entre la force réelle et la force de référence, le circuit 7 transmet une information au circuit d'alimentation du moteur 4 par la ligne 13 ou 14 afin que le moteur 4 soit entraîné en rotation dans un sens ou dans l'autre.At any time, during automatic operation, the pressure sensor member 1 stores in memory 6 the intensity of the force F acting on the patient's limb. Said intensity of the force which appears on the display member 11 is also transmitted to the comparator circuit of the electronic circuit 7, in order to be compared with the value of the reference force stored in memory 5 and displayed in the member 12 display of the reference force. According to the imbalance recorded between the real force and the reference force, the circuit 7 transmits information to the supply circuit of the motor 4 by the line 13 or 14 so that the motor 4 is driven in rotation in one direction or in the other.

Le moteur 4 entraîne en rotation, par les pignons 15 et 16 la vis 3 qui, en agissant par l'intermédiaire de l'écrou 8, provoque le raccourcissement ou l'allongement du tube télescopique 2, 2a. Ainsi, en faisant varier la longueur L du bras d'extension, on augmente ou on diminue la force réelle exercée au point 9 sur le membre du patient.The motor 4 rotates, by the pinions 15 and 16, the screw 3 which, by acting through the nut 8, causes the telescopic tube 2, 2a to shorten or lengthen. Thus, by varying the length L of the extension arm, the actual force exerted at point 9 on the patient's limb is increased or decreased.

Si la force réelle enregistrée à un instant donné dans la mémoire 6 est supérieure à la force de référence enregistrée dans la mémoire 5 et affichée dans l'organe d'affichage 12, le circuit électronique 7 donne une information conduisant à une rotation du moteur 4 entraînant une rotation de la vis 3 de commande dans un sens ou dans l'autre telle que la longueur L est augmentée ou réduite dans le sens où la force réelle tend à devenir égale à la force de référence Fo.If the real force recorded at a given time in memory 6 is greater than the reference force recorded in memory 5 and displayed in the display member 12, the electronic circuit 7 gives information leading to a rotation of the motor 4 causing a rotation of the control screw 3 in one direction or the other such that the length L is increased or reduced in the direction where the real force tends to become equal to the reference force Fo.

La figure 2 montre de façon schématique la conception mécanique d'un dispositif de traction orthopédique équipé d'un contrôleur électronique de tension selon l'invention.FIG. 2 schematically shows the mechanical design of an orthopedic traction device equipped with an electronic tension controller according to the invention.

Le dispositif de traction proprement dit comprend un tube de support 2 qui peut lui- même être monté sur un autre organe de support orientable, non représenté sur la figure 2, et d'un tube 2a coulissant télescopiquement à l'intérieur du tube de support 2. Une vis de commande 3 est engagée dans un écrou 8 solidaire du tube intérieur 2a et se trouve prolongée par une partie non filetée qui est engagée dans un palier 33 emboîté à l'extrémité du tube extérieur 2 opposée au point 9 d'application de l'effort de traction sur le membre du patient. Lorsque la vis 3 engagée dans l'écrou 8 est entraînée en rotation, le tube intérieur 2a, qui porte l'écrou 8 et entoure la vis 3 sur une partie de sa longueur, est déplacé axialement dans un sens ou dans l'autre en coulissant dans le tube extérieur 2 pour modifier la position du point 9 et par suite la force de traction.The actual pulling device comprises a support tube 2 which can itself be mounted on another orientable support member, not shown in FIG. 2, and a tube 2a telescopically sliding inside the support tube 2. A control screw 3 is engaged in a nut 8 secured to the inner tube 2a and is extended by a non-threaded part which is engaged in a bearing 33 fitted at the end of the outer tube 2 opposite the point 9 of application of the tensile force on the patient's limb. When the screw 3 engaged in the nut 8 is rotated, the inner tube 2a, which carries the nut 8 and surrounds the screw 3 over part of its length, is moved axially in one direction or the other by sliding in the outer tube 2 to modify the position of point 9 and consequently the traction force.

Le dispositif 10 de contrôle et d'affichage de tension comprend un boîtier moulé 17 qui vient s'emboîter sur l'extrémité du tube support extérieur 2, autour du palier 33 à l'intérieur duquel tourillonne l'extrémité non filetée de la vis 3.The tension control and display device 10 comprises a molded case 17 which fits onto the end of the external support tube 2, around the bearing 33 inside which the non-threaded end of the screw 3 journals. .

Un arbre de commande de la vis 3 est monté sur un roulement à bille 30 à l'intérieur d'un cadre 127 non rotatif qui reçoit les efforts axiaux exercés sur la vis 3 et supporte l'extrémité 23 d'une jauge de contrainte 1, ou d'un organe équivalent de mesure de force dont l'autre extrémité est fixée au boîtier 17 du dispositif 10.A drive shaft for the screw 3 is mounted on a ball bearing 30 inside a non-rotating frame 127 which receives the axial forces exerted on the screw 3 and supports the end 23 of a strain gauge 1 , or an equivalent force-measuring device, the other end of which is fixed to the housing 17 of the device 10.

Comme cela est représenté sur la figure 4, un pignon 115 est monté sur un manchon 126 coaxial à l'arbre 43 d'un volant 44, pour être entraîné en rotation avec l'arbre 43. Le manchon 126 est relié par un organe d'adaptation 117 à une extrémité d'un levier 37 qui peut pivoter autour d'un point fixe 137.As shown in FIG. 4, a pinion 115 is mounted on a sleeve 126 coaxial with the shaft 43 of a flywheel 44, to be driven in rotation with the shaft 43. The sleeve 126 is connected by a member d adaptation 117 to one end of a lever 37 which can pivot around a fixed point 137.

Dans une première position du levier 37, le pignon 115 est en prise avec un pignon 16 monté sur une partie non filetée de la vis 3. Dans cette position, qui correspond à une phase de commande manuelle, la vis 3 peut être entraînée en rotation par le volant 44. Dans une seconde position du levier 37, qui correspond à la position représentée sur la figure 4, le pignon 115 n'est plus en prise avec le pignon 16 et un contact 107 permet de mettre sous tension un moto-réducteur 4 qui commande alors la rotation de la vis 3 par l'intermédiaire d'un jeu de pignons 15, 16. Dans cette seconde position du levier 37, le moteur électrique 4 est piloté par des circuits électroniques 7 incorporés dans le boîtier 17 et le dispositif est mis en position de maintien automatique de la tension affichée.In a first position of the lever 37, the pinion 115 is engaged with a pinion 16 mounted on a non-threaded part of the screw 3. In this position, which corresponds to a manual control phase, the screw 3 can be rotated by the flywheel 44. In a second position of the lever 37, which corresponds to the position shown in FIG. 4, the pinion 115 is no longer engaged with the pinion 16 and a contact 107 makes it possible to energize a gear motor 4 which then controls the rotation of the screw 3 by means of a set of pinions 15, 16. In this second position of the lever 37, the electric motor 4 is controlled by electronic circuits 7 incorporated in the housing 17 and the device is set to the automatic display voltage maintenance position.

Les organes 11, 12 d'affichage de la force réelle appliquée sur le membre du patient et de la force de référence choisie lors du passage de la position manuelle à la position automatique, peuvent être disposés par exemple sur une face latérale du boîtier 17, ou sur la face supérieure du boîtier 17.The members 11, 12 for displaying the real force applied to the patient's limb and the reference force chosen when switching from the manual position to the automatic position, can be arranged for example on a side face of the housing 17, or on the upper face of the housing 17.

Le dispositif de contrôle selon l'invention permet d'effectuer une lecture directe de la force exercée pendant toute la phase manuelle pendant laquelle il est procédé à la traction sur la jambe du patient jusqu'à la force désirée. Une fois la force de traction atteinte, la manette 37 étant placée en position automatique, le contrôleur électronique est en action et la force de traction exercée est asservie pour rester constante même si la position du patient subit certaines modifications. Les organes d'affichage 11, 12 permettent de lire à chaque instant la valeur de référence et la force réelle mesurée qui est adaptée à l'aide du dispositif de contrôle pour être ramenée à la valeur de référence.The control device according to the invention makes it possible to carry out a direct reading of the force exerted during the entire manual phase during which traction is carried out on the patient's leg up to the desired force. Once the traction force has been reached, the handle 37 being placed in the automatic position, the electronic controller is in action and the traction force exerted is controlled to remain constant even if the position of the patient undergoes certain modifications. The display members 11, 12 make it possible to read at all times the reference value and the real measured force which is adapted using the control device to be brought back to the reference value.

On a représenté sur la figure 5 un mode de réalisation particulier de l'agencement mécanique d'un dispositif de contrôle selon l'invention. Selon ce mode de réalisation, l'extrémité 18 de l'élément fixe 2 du tube télescopique 2, 2a est emboîtée et fixée par des vis de blocage 19 sur le boîtier 17 en aluminium coulé.FIG. 5 shows a mode of particular embodiment of the mechanical arrangement of a control device according to the invention. According to this embodiment, the end 18 of the fixed element 2 of the telescopic tube 2, 2a is fitted and fixed by locking screws 19 on the housing 17 made of cast aluminum.

A l'intérieur du boîtier 17 est disposé l'organe capteur de pression 1 dont l'une des extrémités est fixée par une goupille 20 dans deux logements 21, 21a a d'une rondelle 22 solidaire du boîtier. A son autre extrémité, l'organe capteur 1 est muni d'une tige 23 qui comporte une tête 23a en appui contre deux butées à billes 24, 24a séparées par une entretoise 25 et maintenues serrées par un écrou 26 vissé sur la partie filetée 23b de la tige 23, les butées 24, 24a étant ainsi rendues solidaires d'un manchon intérieur 27 solidaire en rotation d'un manchon extérieur 28 par une clavette 29 permettant le coulissement axial du manchon 27 dans le manchon 28.Inside the housing 17 is arranged the pressure sensor member 1, one end of which is fixed by a pin 20 in two housings 21, 21a has a washer 22 secured to the housing. At its other end, the sensor member 1 is provided with a rod 23 which has a head 23a resting against two thrust ball bearings 24, 24a separated by a spacer 25 and kept tight by a nut 26 screwed onto the threaded part 23b of the rod 23, the stops 24, 24a thus being made integral with an inner sleeve 27 integral in rotation with an outer sleeve 28 by a key 29 allowing the axial sliding of the sleeve 27 in the sleeve 28.

Le manchon extérieur 28 est monté rotatif au moyen d'un roulement à billes 30 et d'un roulement à aiguilles 31 dans le boîtier 17.The outer sleeve 28 is rotatably mounted by means of a ball bearing 30 and a needle bearing 31 in the housing 17.

A l'extrémité opposée à l'organe capteur de pression, le manchon intérieur 27 est rendu solidaire en rotation du prolongement 3a de la vis 3 par une clavette 32, ladite vis 3 étant engagée dans un palier 33 emboîté à l'une des extrémités de l'élément fixe 2 du tube télescopique 2, 2a.At the opposite end to the pressure sensor member, the inner sleeve 27 is made integral in rotation with the extension 3a of the screw 3 by a key 32, said screw 3 being engaged in a bearing 33 fitted at one of the ends of the fixed element 2 of the telescopic tube 2, 2a.

Sur une partie extérieure du manchon 28 est monté coulissant axialement un pignon 34 qui est solidaire en rotation dudit manchon notamment par une clavette, ledit pignon étant soumis à l'action d'un ressort hélicoïdal 35 en appui contre un épaulement du manchon 28 et étant susceptible de coulisser contre l'action du ressort sous l'action d'un doigt 36 d'un sélecteur monté rotatif sur l'un des couvercles latéraux 38, 38a fermant le boîtier 17. Le sélecteur 36 est actionné de l'extérieur par un levier 37 (fig. 6).On an outer part of the sleeve 28 is axially slidingly mounted a pinion 34 which is integral in rotation with said sleeve in particular by a key, said pinion being subjected to the action of a helical spring 35 bearing against a shoulder of the sleeve 28 and being capable of sliding against the action of the spring under the action of a finger 36 of a selector rotatably mounted on one of the side covers 38, 38a closing the housing 17. The selector 36 is actuated from the outside by a lever 37 (fig. 6).

De cette manière, le pignon 34 est susceptible d'engrener soit avec un pignon 39 claveté sur l'arbre de sortie 40 du moteur 4 fixé à l'intérieur du boîtier 17 par l'intermédiaire d'une équerre de fixation 41, soit avec un pignon 42 fixé à l'extrémité d'un arbre 43 monté rotatif dans le boîtier 17 et muni à l'une de ses extrémités d'un volant de manoeuvre 44.In this way, the pinion 34 is capable of meshing either with a pinion 39 keyed onto the output shaft 40 of the motor 4 fixed inside the housing 17 by means of a fixing bracket 41, or with a pinion 42 fixed to the end of a shaft 43 rotatably mounted in the housing 17 and provided at one of its ends with an operating wheel 44.

Sur l'un des couvercles 38a sont montés le circuit électrique de commande d'asservissement du moteur 4 ou moteur-réducteur et le circuit électronique 7 de mesure d'intensité de la force.On one of the covers 38a are mounted the electric control circuit for controlling the motor 4 or motor-reducer and the electronic circuit 7 for measuring the intensity of the force.

Un mode de réalisation possible du circuit électronique 7 est représenté sur la figure 7. L'organe capteur de force ou jauge 1 est relié par l'intermédiaire d'un amplificateur 45 et d'une résistance 71, connectée en série à la sortie de l'amplificateur 45, à l'une des entrées 46 d'un circuit comparateur 47 dont l'autre entrée 48 est reliée, par l'intermédiaire d'une résistance 72, à un potentiomètre de réglage 49. Des résistances 75, 76, 77 permettent d'ajuster les paramètres du circuit comparateur 47. Deux diodes 73, 74 sont en outre montées en parallèle entre les entrées 46 et 48 du comparateur 47, la cathode de chacune des diodes étant reliée à l'anode de l'autre diode.A possible embodiment of the electronic circuit 7 is shown in FIG. 7. The force sensor or gauge member 1 is connected via an amplifier 45 and a resistor 71, connected in series to the output of the amplifier 45, to one of the inputs 46 of a comparator circuit 47, the other input 48 of which is connected, via a resistor 72, to an adjustment potentiometer 49. Resistors 75, 76, 77 allow the parameters of the comparator circuit 47 to be adjusted. Two diodes 73, 74 are furthermore mounted in parallel between the inputs 46 and 48 of the comparator 47, the cathode of each of the diodes being connected to the anode of the other diode .

La sortie 50 du comparateur 47 est reliée, par l'intermédiaire du circuit série composé d'une diode zener 78 et d'une résistance 79, à la base d'un transistor 51, dont le collecteur est monté en série avec un contact 52 d'un second relais 54 et avec la bobine 8, d'un premier relais 53, elle-même montée en parallèle avec une diode de protection 82. De façon similaire, la sortie du comparateur 47 est reliée, par l'intermédiaire du circuit série composé d'une diode zener 80 et d'une résistance 81, à la base d'un second transistor 52, de type complémentaire de celui du transistor 51 et dont le collecteur est monté en série avec un contact 51 du premier relais 53 et avec la bobine B2 du second relais 54, elle-même montée en parallèle avec une diode de protection 83.The output 50 of the comparator 47 is connected, via the series circuit composed of a zener diode 78 and a resistor 79, to the base of a transistor 51, the collector of which is connected in series with a contact 5 2 of a second relay 54 and with the coil 8, of a first relay 53, itself mounted in parallel with a protective diode 82. Similarly, the output of the comparator 47 is connected, via the series circuit composed of a zener diode 80 and a resistor 81, at the base of a second transistor 52, of a type complementary to that of transistor 51 and the collector of which is connected in series with a contact 5 1 of the first relay 53 and with the coil B 2 of the second relay 54, itself mounted in parallel with a protection diode 83.

Lorsque le moteur 4 est mis sous tension par l'intermédiaire du commutateur 92, qui est actionné lors de la manoeuvre de la manette 37 de passage du fonctionnement manuel au fonctionnement automatique, la fermeture soit des contacts 8, du premier relais 53, soit des contacts B2 du second relais 54 permet d'alimenter sélectivement le moteur électrique 4 dans un sens ou dans l'autre.When the motor 4 is energized by means of the switch 92, which is actuated during the operation of the lever 37 for switching from manual operation to automatic operation, the closing either of the contacts 8, of the first relay 53, or of the contacts B 2 of the second relay 54 makes it possible to selectively supply the electric motor 4 in one direction or the other.

L'effort réel appliqué au moyen de la vis 3 sur la jambe du patient est déterminé par l'organe capteur de force 1 qui délivre à la sortie de l'amplificateur 45 une tension proportionnelle à l'effort réel exercé. Cette tension est appliquée sur la première entrée 46 du comparateur 47 dont la deuxième entrée est reliée au potentiomètre 49.The actual force applied by means of the screw 3 to the patient's leg is determined by the force sensor member 1 which delivers at the output of the amplifier 45 a voltage proportional to the actual force exerted. This voltage is applied to the first input 46 of the comparator 47, the second input of which is connected to the potentiometer 49.

Lors de la phase manuelle au cours de laquelle la vis 3 est commandée par le volant 44, et le commutateur 92 est ouvert, mettant hors service le moteur 4, la tension fournie sur l'entrée 46 du comparateur représente l'effort réel progressivement exercé manuellement sur la jambe du patient. Cette tension permet l'affichage d'une valeur d'effort réel exercé, sur un organe d'affichage, tel que l'organe d'affichage 11 de la figure 1. Lorsque la valeur d'effort réel souhaitée est obtenue, le potentiomètre 49 est réglé de manière à indiquer une valeur nulle sur le voltmètre ou vumètre 55 à haute impédance placé entre la sortie du comparateur 47 et le curseur du potentiomètre 49. Lorsque le vumètre 55 est à zéro, il existe un équilibre des tensions sur les entrées 46 et 48 du comparateur 47. Ceci signifie que la tension de référence a été choisie égale à la valeur de la force réelle atteinte lors de la fin de la phase manuelle.During the manual phase during which the screw 3 is controlled by the flywheel 44, and the switch 92 is open, putting the motor 4 out of service, the voltage supplied on the input 46 of the comparator represents the real force gradually exerted manually on the patient's leg. This voltage makes it possible to display a value of actual force exerted on a display member, such as the display member 11 of FIG. 1. When the desired value of actual effort is obtained, the potentiometer 49 is set so as to indicate a zero value on the high impedance voltmeter or vumeter 55 placed between the comparator output 47 and the potentiometer cursor 49. When the vumeter 55 is at zero, there is a balance of the voltages on the inputs 46 and 48 of comparator 47. This means that the reference voltage has been chosen equal to the value of the real force reached at the end of the manual phase.

Après passage en fonctionnement automatique à l'aide de la manette 37 de la figure 6, le volant 44 est débrayé, le moteur 4 est mis en prise avec la vis 3, et le commutateur 92 est fermé. Lors de ce fonctionnement en automatique, lorsque l'effort de traction change, l'organe capteur de force 1 délivre une nouvelle tension telle que l'équilibre entre les deux tensions aux bornes du vumètre 55 est rompu. La nouvelle valeur de la tension sur l'entrée 46 du comparateur 47 modifie la tension de sortie du comparateur 47 qui fournit une tension par basculement soit sur le transistor 51, soit sur le transistor 52, entraînant ainsi une alimentation du moteur 4 par le relais 53 ou le relais 54 et par suite une rotation du moteur dans un sens ou dans l'autre.After switching to automatic operation using the handle 37 of Figure 6, the flywheel 44 is disengaged, the motor 4 is engaged with the screw 3, and the switch 92 is closed. During this automatic operation, when the tensile force changes, the force sensor member 1 delivers a new voltage such that the balance between the two voltages at the terminals of the meter 55 is broken. The new value of the voltage on the input 46 of the comparator 47 modifies the output voltage of the comparator 47 which provides a voltage by tilting either on the transistor 51 or on the transistor 52, thus causing a supply of the motor 4 by the relay 53 or the relay 54 and consequently a rotation of the motor in one direction or the other.

Le sens de rotation du moteur est tel que la tension enregistrée par la jauge 1 a tendance à revenir dans sa position initiale telle que le vumètre 55 revienne dans sa position d'équilibre indiquant zéro.The direction of rotation of the motor is such that the voltage recorded by the gauge 1 tends to return to its initial position such that the meter 55 returns to its equilibrium position indicating zero.

Suivant une caractéristique supplémentaire du circuit électronique 7, représenté sur la figure 8, on utilise un dispositif électrique de réglage de la vitesse de réaction des transistors 51 et 52 de la figure 7.According to an additional characteristic of the electronic circuit 7, represented in FIG. 8, an electrical device for adjusting the reaction speed of the transistors 51 and 52 of FIG. 7 is used.

Des transistors 56, 57, dont les collecteurs sont reliés par des résistances de polarisation 89, 90 à la ligne + V d'alimentation, oscillent à des fréquences prédéterminées par un circuit comprenant un potentiomètre 58 et des condensateurs 61, 62. Le condensateur 61 est connecté entre lé collecteur du transistor 57 et le collecteur du transistor 56 tandis que le condensateur 62 est connecté entre la base du transistor 57 et le collecteur du transistor 56. Le potentiomètre 58 monté entre les bases des transistors 56, 57 a son curseur relié à un pont diviseur formé des résistances 87, 88 connectées entre l'alimentation + V et la masse. Le collecteur du transistor 57 est relié à deux optocoupleurs 59, 60 montés en série avec une résistance 91. Les optocoupleurs effectuent un découpage de la tension entre d'une part les bornes c et d et d'autre part les bornes e et f du circuit de la figure 7, ce qui modifie les temps de réaction des transistors 51 et 52. Le potentiomètre 58 permet de régler manuellement la vitesse de réaction des transistors 51, 52.Transistors 56, 57, the collectors of which are connected by polarization resistors 89, 90 to the + V supply line, oscillate at predetermined frequencies by a circuit comprising a potentiometer 58 and capacitors 61, 62. The capacitor 61 is connected between the collector of transistor 57 and the collector of transistor 56 while the capacitor 62 is connected between the base of transistor 57 and the collector of transistor 56. Potentiometer 58 mounted between the bases of transistors 56, 57 has its cursor connected to a divider bridge formed by resistors 87, 88 connected between supply + V and earth. The collector of transistor 57 is connected to two optocouplers 59, 60 connected in series with a resistor 91. The optocouplers carry out a voltage cutting between on the one hand the terminals c and d and on the other hand the terminals e and f of the circuit of FIG. 7, which modifies the reaction times of the transistors 51 and 52. The potentiometer 58 allows manual adjustment of the reaction speed of the transistors 51, 52.

Claims (5)

1. Device for displaying and controlling (10) the force applied on the extendible arm of an orthopedic table, said arm being moved according to an extending and retracting movement by a telescopic tube (2, 2a) actuated by a screw (3) and nut (8) transmission, the screw (3) of which can be driven in rotation by hand by means of an operating member (44) characterized in that it comprises a force sensing member (1) interposed between the screw (3, 3a) controlling the tube (2, 2a) and a fixed point of the arm such as a casing (17) of the same device, said sensing member (1) being connected to display means (6, 11) displaying the force F recorded by the sensing member (1), in that it comprises an electric motor (4) permitting the automatic driving in rotation of the screw (3) and switching means (37, 92) for driving the screw, either manually from said driving member (44), or automatically from an electric motor (4), and in that it further comprises an electronic circuit (7) permitting, in automatic operation position, the comparison of two forces, one of which is the force F recorded by the sensing member (1) and the other is a selected reference force Fo previously obtained in a position of manual control of the screw (3) by storing the force recorded by the sensing, member (1) before switching to the automatic operation position, said electronic circuit (7) reacting when in automatic operation position, to any variation of the force F recorded by the sensing member (1) with respect to reference force Fo, and issuing pulses which are transmitted to the electric motor (4) for driving the endless screw (3) in rotation in one direction or the other, so as to cause a variation of length L of the telescopic tube (2, 2a) toward an unbalance between forces F and Fo in such a manner that the recorded force F is brought back to the value of reference force Fo.
2. Device according to claim 1, characterized in that the electronic circuit (7) is connected to display means (5, 12) displaying a reference force Fo and to display means (6, 11) displaying the actual force F recorded by the actual force sensing member (1).
3. Device according to claim 1, characterized in that the electronic circuit comprises a comparator (47) of which one of the inputs (46) is connected via an amplifier (45) to the force sensing member (1) and of which the other input (48) is connected to a preset potentiometer (49), said comparator (47) having its output (50) connected, on the one hand, to a voltmeter (55) and on the other hand, to the bases of the two transistors (51, 52) supplying respectively two relay coils (53, 54) controlling the selective supply of the electric motor (4) in order to rotate it in one direction or the other, when the electric motor (4) is started by a switch (92).
4. Device according to claim 3, characterized in that it further comprises two transistors (56, 57) oscillating at frequencies preset by a control (58) and connected with optocouplers (59, 60) giving a hatching of the voltage applied (in CD and EF) on the base-emitter space of transistors (51, 52) in order to alter the reaction time of said transistors (51, 52).
5. Device according to claim 1, characterized in that it comprises a casing (17), on which is fixed, at one of its ends, one element of the telescopic tube (2) and in which is rotatably mounted one of the ends of the endless screw (3) which is joined to an internal sleeve (27), fast in rotation with an external sleeve (28) but which is mounted for sliding axially with respect to said external sleeve, and which is joined via roller thrust bearings (24, 24a) to one of the ends of the force sensing member (1) of which the other end is secured to the casing (17), said external sleeve (28) being mounted for rotating in the casing (17) and being fast in rotation with a pinion (34) mounted for sliding axially on said external sleeve (28), so as to mesh selectively with a pinion (39) driven in rotation by the electric motor (4) and with a pinion (42) driven in rotation by a hand- operated control member (44).
EP19860400481 1985-03-08 1986-03-07 Device displaying and controlling the traction applied to the extension arm of an orthopaedic table Expired EP0194206B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8503460A FR2578418B1 (en) 1985-03-08 1985-03-08 DEVICE FOR DISPLAYING AND CONTROLLING THE FORCE APPLIED TO THE EXTENSION ARM OF AN ORTHOPEDIC TABLE
FR8503460 1985-03-08

Publications (2)

Publication Number Publication Date
EP0194206A1 EP0194206A1 (en) 1986-09-10
EP0194206B1 true EP0194206B1 (en) 1989-02-01

Family

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Application Number Title Priority Date Filing Date
EP19860400481 Expired EP0194206B1 (en) 1985-03-08 1986-03-07 Device displaying and controlling the traction applied to the extension arm of an orthopaedic table

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EP (1) EP0194206B1 (en)
DE (1) DE3661984D1 (en)
ES (1) ES8706025A1 (en)
FR (1) FR2578418B1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4520710B2 (en) * 2003-05-22 2010-08-11 衛 光石 Power assist control device, power assist control method, and reduction device
CN107412909B (en) * 2017-09-05 2020-10-02 马鞍山欧格萨斯机械科技有限公司 Auxiliary transfusion device for myasthenia patient

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB537653A (en) * 1939-11-28 1941-07-01 James Wolfe Alexander Improvements relating to metal testing machines
FR2210287A5 (en) * 1972-12-07 1974-07-05 Creusot Loire
US3952235A (en) * 1974-06-10 1976-04-20 Tru-Eze Manufacturing Co., Inc. Control system for electrodynamic mechanism
NL7611461A (en) * 1976-10-15 1978-04-18 Enraf Nonius TRACTION DEVICE.
US4365623A (en) * 1980-03-06 1982-12-28 Tru-Eze Manufacturing Co. Apparatus to exert traction in traction therapy

Also Published As

Publication number Publication date
FR2578418A1 (en) 1986-09-12
FR2578418B1 (en) 1989-04-21
ES8706025A1 (en) 1987-06-01
ES552795A0 (en) 1987-06-01
EP0194206A1 (en) 1986-09-10
DE3661984D1 (en) 1989-03-09

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