The present invention relates to a nut drive devices comprising a screw-nut system. In this type of devices, the rotation of a threaded rod causes translation of a nut connected to the threaded shaft by a helical connection along the longitudinal axis of the rod.

This type of device is particularly implemented in detection devices for controlling helicopter against underwater threats in which an antenna for detecting underwater threats is suspended from an aerial platform such as an aircraft, which allows the immersing the antenna. The antenna comprises transmitters and receivers themselves and possibly electronic equipment associated with the transmitters and receivers. It may also include environmental sensors. In addition, on board of the air platform, the sensing device comprises the equipment required for the generation of acoustic signals and processing acoustic data received.

An example sensing device is shown in Figure 1. It comprises a winch 100 to be installed in an aerial platform. The airborne control device comprises an antenna 101 suspended at the end of an electro-hauling rope 102 of the winch 100, optionally with a funnel 103 (or "funnel" in English terminology) as is the case in figure 1 . The winch 100 is designed to make the deployment and retrieval of the antenna 101. In Figure 1 the winch 100 is fixed on a floor 200 of an aerial platform. The electro-hauling rope 102 can convey signals as well as electrical energy for acoustic remission and / or operation of the receivers. When pulling the cable 102 with the winch 100, the antenna 101 is down, through the funnel 103 possible in the water. Winding the cable 102 allows the antenna 101 back into the aerial platform within the possible funnel 103 as shown in Figure 1.

The antenna 101 has a shape of substantially cylindrical elongate dome. It comprises an elongated body 1 12 having an outer circumference substantially circular section in a plane perpendicular to the longitudinal axis z of the antenna 101. The elongated body 1 12 is surrounded by a protective structure 1 13 (or "bumper in Anglo-Saxon terminology") having an outer circumference substantially circular section in a plane perpendicular to the longitudinal axis z of the antenna 101. The outer circumference of the protection assembly 1 13 and the outer circumference of the elongated body 1 12 are substantially concentric. When the antenna 101 is suspended by its own weight to the cable 102, the latter also extends along the longitudinal axis z.

Maintain the antenna 101 in position in the aerial platform only by the cable 102 does not provide a sufficient level of safety when the aerial platform is in transit in particular over populated areas. The cable 102 can break, it can be accidentally cut by the pyrotechnic shears security, the winch brake

100 can accidentally let go and release the cable. The loss of the antenna

101 means a significant financial loss, but most of its large mass could fall at sea or ground causing serious material or human damage.

The antenna position 101 with respect to the winch 100 to be locked when it is in position on board of the air platform. The sensing device then advantageously comprises a strapping device 104 to lock the antenna position 101 with respect to the winch 100 so as to prevent accidental fall of the antenna and its consequences.

A strap of the prior art device 104 is shown in Figure 2. It comprises a hoop 105 comprising a clamping band 106 and the pads of 1 14 to be interposed between the protective structure 1 13 and the clamping band 106 . It also includes a drive device 1 15 enabling moving of the longitudinal ends 1 10 and 1 1 1 of the clamping band 106 relative to each other to reduce the size of the loop so as to be able to grip an object, for example the protection assembly 1 13 of the antenna 101 at a said clamping step, or increase the size of the loop so as to loosen or release an object initially contained by the strap 105, when a so-called release stage.

Each Endpoint 1 10 and 1 1 1 of the clamping band 106 is secured to a nut 121 and 122 respectively, in translation relative to the threaded rod 1 18 according to the axis x. The nuts are engaged with the threads of the threaded rod made in opposite direction so that the clamping and unclamping are performed by moving the ends of the clamping band 106 in the opposite direction along the longitudinal axis of a 1 threaded rod 18. the drive of the threaded rod 1 18 rotation may be accomplished by a motor not shown by an operator or by means of a wheel, via a not shown gear.

The clamping band 106 must be limited to prevent damage to the antenna or damage of the screw-nut system or simply to allow loosening. Indeed, excessive tightening can result in blocking of the nut on the threaded rod requiring excessive torque to be exerted to release the antenna. It is possible to limit the travel as well that the tightening loosening.

In order to limit the stroke of the nut, the drive device comprises a control member for controlling the engine and two position sensors for detecting the size limits loops in the direction of tightening and loosening. The controller stops the engine after detection limits loop sizes.

As shown in Figure 2, each position sensor comprises a push button switch 123 and 124 fixed to the frame 109 and an actuator in the form of an abutment 125 and 126 respectively fixed to one of the nuts 121 and respectively 122. The stop 125 is supported on the push button 127 of the switch 123 and pushes the perpendicular to the x axis of the threaded rod 1 18 so as to close the switch 123 when, during the release phase, the size of the loop reaches a threshold value which corresponds to a threshold position of the nut 121 along the threaded rod 1 18 loosening. The stop 126 abuts on the push button 128 and pushes perpendicularly to the x axis of the threaded rod 1 18 close the switch 124 when, during the tightening phase, the size of the loop reaches another threshold value that corresponds to a threshold position of the nut 122 along the threaded rod 1 18 in the tightening. Pivotable ramps about axes perpendicular to the plane of Figure 2 are provided at the interface between each push button 127 or 128 and its stop 125 or 126 so as to avoid deterioration of the push button 127 or 128.

The Applicant has found that sensors become incorrect operation in which the effect of changing the values ​​of detected threshold sizes and leads to clamping and / or excessive loosening

may damage the drive device and the antenna. To avoid these excesses, a sensor adjustment is necessary before each operation.

An object of the invention is to provide a driving device comprising a position sensor for detecting a predetermined position more reliably.

To this end, the invention relates to a drive device comprising:

- a frame,

- a screw-nut system comprising a threaded rod and a first nut in helical connection with the threaded rod, the threaded rod being connected to the frame by a pivot connection to allow the threaded rod to rotate relative to the frame about a longitudinal axis the threaded rod,

- a first position sensor for detecting a first limit position of the nut along the longitudinal axis, the first position sensor comprising a first portion and a second portion, the first position sensor being responsive to a variation of a distance between the first portion and the second portion of the first sensor position along the axis,

the first portion being fixed to the first nut and the second part being linked to the threaded rod without passing through the pivot connection and such that rotation of the threaded rod around the longitudinal axis causes a variation in distance between the first part and the second portion of the first sensor position along the longitudinal axis.

Advantageously, the device comprises at least one of the following features taken alone or in combination:

- the second part of the first sensor is helically connected to the threaded rod,

- the screw-nut system comprises a second nut helical connection with the threaded rod, the first nut being engaged with a first thread of the threaded rod and the second nut being in engagement with a second thread of the threaded rod, the first thread and the second thread being formed in opposite direction, the drive device comprising a second position sensor for detecting a second limit position of the nut along the longitudinal axis relative to the frame, the second position sensor comprising a first portion and a second portion,

the second position sensor being sensitive to a distance variation between the first portion and the second portion of the second position sensor along the axis,

the first portion of the second position sensor being fixed to the second nut and the second portion of the second position sensor being linked to the threaded rod without passing through the pivot connection and such that rotation of the threaded rod around the longitudinal axis results in a distance variation between the first portion and the second portion of the second position sensor along the longitudinal axis,

- the first thread and the second thread are of even called first step,

- the second part of the second sensor is helically connected to the threaded rod,

- the second part of the two sensors is in engagement with one additional thread,

- the second thread has a second step, the additional thread being made of the same direction as the second thread and has a third pitch different from the second step,

- the additional thread is interposed between the first thread and the second thread has a third and not more than the first pitch,

- the first portion and the second portion of the first sensor comprises a push button switch and an actuator for actuating a push button of the push button switch to cause a change of state of the switch,

- the first position sensor is configured to be responsive to a variation in distance between the first part and the second part along the x axis but not to a change of relative angular position between its first part and its second part around the x-axis,

- the pushbutton is in sliding connection parallel to the longitudinal axis with a fixed part of the switch and the abutment extends in a plane substantially perpendicular to the longitudinal axis,

- it comprises a motor coupled to the threaded rod to allow to cause the threaded rod to rotate about its longitudinal axis,

- it comprises a control member for controlling the motor, the controller receiving measurements from the first

position sensor and being adapted to control the motor from the measurements,

- the controller receives measurements from the second position sensor, the controller being configured to stop the motor upon detection of the limit position of the first nut when the threaded rod rotates in a first direction, and a deferred manner after detecting the limit position of the second nut when the threaded rod rotates in the opposite direction.

The invention also relates to a banding device for encircling an object by means of a strap comprising a clamping band comprising a first end and a second end and forming a loop intended to surround the object, the strapping device comprising a drive device according to the invention, for moving the two ends relative to each other to enlarge or reduce the size of the loop, the first end of the strap being secured to the first nut in translation along the axis of the threaded rod.

Advantageously, the second end is integral with the second nut in translation along the axis of the threaded rod.

The loop may be closed.

The invention also relates to a holding device for clamping a hollow object, said device comprising a first flange and a second flange adapted to abut on a hollow object, inside the hollow object, the apparatus holding comprising a drive device according to the invention, the drive device being configured to move the two flanges relative to one another so as to separate them from one another to grip the object or together to release the object, the insole being integral with the first nut in translation along the axis of the screw shaft, the screw-nut system comprising a second nut engaged with a second thread formed in the opposite direction first thread,the second flange being integral with the second nut in translation along the axis of the threaded rod.

The invention will be better understood studying a few embodiments described by way of non-limiting example, and illustrated by the accompanying drawings wherein:

- Figure 1, already described, schematically represents a detection device,

- Figure 2 shows schematically sectional strapping encircling an antenna and a drive device of the prior art,

- Figure 3 shows diagrammatically a strapping device according to the invention,

- Figures 4 and 5 show schematically in section (Figure 4) and perspective (Figure 5) the drive means in more detail,

- Figure 6 shows a schematic kinematic diagram of the driving device,

- Figure 7 shows a partial view of a holding device according to the invention.

On the one figure to another the same elements are designated by the same numerals.

The invention relates to a drive device to screw-nut system. This device can be used in a strapping device 4 intended to be integrated in a control device or airborne detection device as shown in Figure 1. The strapping device 4 then replaces the strapping device 104. The invention also relates to the strapping device 4 and the detecting device as shown in Figure 1 with the strapping device 4 according to the invention. The strapping device 4 can more generally be used to enclose any type of object, preferably of circular section.

The screw-nut system of the type driving device can be used for devices other than strapping devices which require driving a nut along a threaded rod and detecting a position of the nut along the screw. For example, the drive device can be implemented in a machine tool in which a table moves in translation. The implementation of the invention is useful for detecting a position of the plate.

As shown in Figure 3, the strapping device 4 according to the invention comprises a strapping 5 adapted to encircle an object, for example an antenna 101 and specifically its protective structure 1 13, for example, substantially circular section, and allowing to grip or release the object. Strapping 5 comprises a clamping band 6

forming a loop intended to surround the object 101. The clamping band 6 comprises two longitudinal ends 10 and 1 1.

The strapping device 4 also comprises a clamp / release 15 or drive device for moving the ends 10 to 1 1 of the clamping band 6 relative to each other to reduce the size of the loop so as to be able to grip an object, for example the antenna 101, at a said clamping step, or increase the size of the loop so as to loosen or release a contained object initially by strapping 5, during a so-called release stage. The change in size of the loop is a variation of the length of the perimeter of the loop, that is to say the diameter of the loop. Shortening the perimeter of the loop which occurs during clamping, generates a pressure on the object to grip 101 and creates an interference fit between the rim 5 and the object 101. To maintain the clamping of the object 101, the tightening / loosening 15 keeps tensile loads on the free ends of the strapping 5. A frame 19 defines a receiving housing 19a strapping 5. The housing 19a has here a circular section in the z-axis (perpendicular to the plane of Figure 3).

The clamp / release 15 comprises a screw-nut system comprising a threaded rod 18 and at least one nut 20. More detailed views of the drive mechanism 15 are shown in Figure 4 (sectional) and Fig 5 (in perspective).

The threaded rod 18 is connected to the frame 19 by a pivot connection 218, visible in Figure 3, allowing the threaded rod 18 from rotating relative to the frame 19 about a longitudinal axis x of the threaded rod 18. The link 218 is for example formed by two plain bearings made in two respective trays 218a, 218b integral with the frame 19, visible in Figure 4, spaced along the x axis. The connection 218 may be realized otherwise, for example by means of one or two rolling bearings.

The screw-nut system also comprises a first nut 20 attached in helical connection to the threaded rod 18 and the frame 19 by a bond preventing the nut from turning relative to the frame 19 about the axis x. In Figure 5, the trays 220a and 220b parallel to each other and to the axis of the rod 18 are disposed on either side of the nut 20 so as to clamp the nut 20. The screw-nut system comprises a second nut 21 in helical connection with the threaded rod 18 and connected to the frame 19 via a link 221 a, 221 b prevent the nut 21 from rotating relative to the frame 19 about the axis x. In Figure 5, trays 221a and 221b parallel to each other and to the axis of the rod 18 are disposed on either side of the nut 21 so as to clamp the nut 21. The plates 220a,

The nut 20 is engaged with a first thread 22 of the threaded rod 18, shown schematically in Figure 3, and the nut 21 is engaged with a second thread 23 of the threaded shank 18. The threads 22 and 23 are made in reverse and may have the same pitch. Different pitches are also possible. The first end 10 of the clamping band 6 is integral with the nut 20 in translation relative to the frame 19 along the x axis and the second end 1a 1 of the clamping band 6 is integral with the nut 21 in translation relative to the frame 19 along the x axis. Therefore, the screw-nut system is configured to move both ends of the clamping band 10 to 1 1 in the opposite directions parallel to the x-axis relative to the frame 19 when the threaded rod 18 rotates about its axis in one direction (tightening) and in opposite direction (loosening). The ends 10 and 1 out of 1 approach each other when loosening and away from each other during tightening. In the embodiment of the figures, each end 10 and 1 1 is pivotally connected with a nut 20 and 21 respectively about an axis perpendicular to the plane of the loop formed by clamp band 6. Alternatively, the ends 10 and 1 1 may be integral with the respective nuts 20 and 21, that is to say set to the nuts or integral with the nuts.

In the embodiment of the figures, the screw-nut system comprises two nuts 20 and 21 each connected at one end 10 and, respectively, 1 1. Alternatively, it comprises a single helical connection nut with the threaded shaft 18 and fixed in rotation about the x-axis relative to the frame 19 and integral with one end of the clamping band in translation relative to the frame according the x-axis so as to cause said end relative to the frame along the x axis. The other end is for example fixed to the frame 19.

As shown in Figure 5, the clamping / releasing device comprises a gear train 30 comprising two sprockets 33, 34

into engagement with each other for driving the screw in rotation. A motor 50 (shown in Figure 5) makes it possible to drive the wheel 34 in rotation. The gear train 30 transmits the rotation movement to the threaded rod 18 via the wheel 33. The motor 50 is for example coupled to the wheel 34 through an unillustrated reduction gear.

The drive device 15 comprises a controller 61 for controlling a motor 50. This member controls the motor based on information from position sensors 70, 80 shown in Figure 3. Each position sensor 70 or 80 is adapted to detect a predetermined position of a nut 20 or 21 with respect to the threaded rod 18 along the longitudinal axis x corresponding to a given size of the loop. The sensor 70 is configured to detect a limit position of the nut 20 relative to the threaded rod 18 along the x axis corresponding to a size limit loosening of the loop. The sensor 80 is configured to detect a limit position of the nut 21 relative to the threaded rod 18 along the x axis corresponding to a clamping size limit of the loop.

The controller 61 is configured to stop the motor 50 when the limit loosening size is reached when the threaded rod 18 rotates in a direction corresponding to release and when the clamping size limit is reached while the threaded rod 18 rotates In the opposite way. These judgments can be instant or delayed as we will see later.

As shown in Figure 3, each sensor 70 or 80 comprises two parts, a first part 71 or 81 attached to the corresponding nut 20 or 21 respectively. In other words, each first portion 71 and 81 is helically connected to the threaded rod 18 via one of the nuts 20 and 21 respectively.

Each sensor comprises a second part 72 which here is common to both sensors 70 and 80 and forms a plate perpendicular to the x-axis which will be described more precisely below. The second part 72 is mounted so that rotation of the threaded rod 18 about a longitudinal axis x of the threaded rod 18 causes a variation in distance between the first portion 71 or 81 and the second part 72 of position sensor 70 or respectively 80 along the longitudinal axis x of the threaded rod 18, the position sensor 70 or 80 respectively being configured to be sensitive to this distance variation.

According to the invention, as shown in Figure 3, the second portion 72 is linked to the threaded rod 18 without passing through the pivot connection 218 shown in Figure 3. In fact, the pivot link 218 has an axial play according to x axis. This is an imperfect pivot link. With the assembly according to the invention, the game of this link 218 that is highly sought has no impact on the setting when the sensor has the advantage of being stable, precise and controlled. Saves the set of pivot link 218 between the two portions of each sensor 70, 80.

In the embodiment of the figures, the portion 72 is helically connected to the threaded rod 18 and is connected to the frame 19 by a bond preventing rotation of the part 72 relative to the frame 19. This is achieved by means of two legs 272a, 272b visible in Figure 5, longitudinally extending along the x axis and spaced apart along an axis perpendicular to the x axis so as to clamp a block 200 secured to the plates 220a and 220b which are themselves prevented from rotating relative to the frame 19 about the axis x.

The part 72 is then in engagement with a thread 73, shown schematically in Figure 3, the threaded rod 24 via a nut.

Alternatively, one can link a part of the two parts of a position sensor to the threaded rod 18, making it integral with the threaded rod 18, or by fixing to the threaded rod 18 in translation along the x-axis and by fixing to the frame 19 in rotation about the x axis. These links do not pass through the pivot connection 218.

In the non-limiting embodiment of the figures, as can be seen in Figure 4, the first part 71, 81 of each sensor is a push switch. The second portion 72 is realized actuator, here in the form of a stop. The actuator 72 allows to actuate the push button 75 or 85 to cause a change of state of the switch. Each switch is adapted to be either in a closed state or in an open state. A switch status change corresponds to an open state the passage in the closed state or vice versa.

The first switch 71 and its actuator 72 are configured and arranged so that the first actuator 72 causes a change in state of the first switch 71 when the first nut 20 reaches its limit position relative to the threaded rod 18 along the x axis. This limit position corresponds to the release limit size of the loop. The second switch 81 and the second actuator 72 are configured and arranged so that the second actuator 72 causes a change in state of the second switch 81 when the second nut 21 reaches its limit position relative to the threaded spindle 18 according to the x axis. This position corresponds to the clamping size limit of the loop state change information of each switch is transmitted to the controller 61.

The push button switch 71 or 81 is attached to a nut 20 or 21. The push button switch 71 or 81 comprises a fixed portion 74 or 84 secured to the nut 20 or 21. The fixed part 74, 84 comprises a circuit not shown. The switch includes a push button 75 or 85 movable in translation relative to the fixed part 74 or 84. The stationary part 74 or 84 comprises a contact normally open. The push button 75 or 85 may come into physical contact with the fixed circuit portion to close the circuit. The switch then moves to the closed state. The switch is open when the push button is remote from the circuit. Alternatively, at least one switch contact is of the normally closed type.

The push buttons 75 and 85 are movable in translation relative to the respective fixed portions 74 and 84 substantially parallel to the x axis. In other words, each push button 75 or 85 is in sliding connection with the nut 20 or 21 parallel to the axis x. Each push button 75 or 85 is interposed between the contact of the switch 71 or 81 and the stop 72 along the x axis. The push button 75 or 85 will therefore come close the switch 71, 81 when the stopper 72 will move closer to the fixed portion 74 or 84 and come to push the push button 75 or 85 to contact therewith.

As shown in Figure 3, the abutment 72 is in engagement with a thread 73 of the threaded rod which is carried out in the same direction as the thread 23 (engaged with the nut 21) but in the opposite direction of the thread 22 (in engagement with the nut 20). The thread 73 has a pitch different from the thread 23 so as to ensure approximation of the two parts 72 and 71 at least when the threaded rod rotates in one direction. On the non-limiting example of the figures, threads 22 and 23 have a pitch of 1, 5 mm / revolution, the thread 73 has a pitch of 1 75 mm.

Operation of the device is as follows. Starting from an initial position in which the central nut 24 (or the stopper 72) is in the center, the clamping band 6 is in an intermediate position between clamped and

loose. By operating the threaded rod 18 in one direction about the axis x, the nuts 20 and 21 move in opposite direction as the threads 22 and 23 are carried out in reverse. In this meaning, for example the loosening direction, the nuts 20 and 21 move towards each other along with them the ends 10 to 1 1 of the clamping band 6. The size of the loop increases. The stop 72 is in the opposite direction of the nut 20 and approximates it. The stop 72 goes to meet the push button 75 at a rate of 3.75 mm / rev. The stop 72 comes into contact with the first push button 75, is moving relative to the fixed part 74, in the direction x in the direction of movement of the stop 72 and thus into contact the contact of the switch 71 so as to cause the change in state of switch 71. The limit position of the nut 20 along the axis x with respect to the threaded rod 18, corresponding to the release limit size of the loop is then detected. This information is sent to the controller 61. Advantageously but not necessarily, the controller 61 is configured to stop the motor 50 when the limit position of the nut 20 is detected when the threaded rod 18 rotates in the loosening direction. The strapping 6 is for example returned fully into its housing 19a in frame 19, and it is not necessary that it sinks further under penalty of stuck there. The stop must be very precise because during the following recovery of the antenna must be certain that the strapping is open to the maximum without risk of jamming. This significant relative speed between stop 72 and the first push button 75 allows very precise control. At the opening, well adjusted strapping 6 will stop its movement always in the same position. Alternatively, the controller 61 stops the motor 50 with a delay after the boundary position detection of the nut 20 upon release, that is to say when the threaded rod 18 rotates in the tightening direction.

Now when the motor 50 rotates the threaded rod 18 in opposite direction about the axis x, that is to say in the clamping direction. The nuts 20 and 21 moving in opposite direction then away from one another and the size of the loop decreases. The stop 72 moves in the same direction as the nut 21, but a little faster since the step is 1, 75. The stop 72 will then gradually catch up the push button 85 at 0.25 mm / rev. The stopper 72 catches up with the push-button 85 comes to drive it in translation along the x axis to the contact with the fixed portion 84 which causes the change of state of the switch 81. The limit position of the nut 21 relative to the threaded rod 18 along the x axis corresponding to the clamping limit size of the loop is detected. This information is transmitted to the controller 61 which stops the motor to stop the clamping, preferably but not necessarily, with a delay after reception of the detection information. When the clamping size limit is reached, the motor continues to drive the rod 18 for clamping the clamping band until the loop reaches a predetermined size threshold. This ensures a complete tightening of the antenna regardless of the diameter of the antenna in a predetermined range of diameters. It is observed that the tightening still benefit from a wide range of uncertainty since the advancement of the contact is only 0.25 mm / rev in relative. This wide range allows to easily accommodate antennas of different diameters provided that the delay on actual engine stop after contact is sufficient. Furthermore, the low speed relative advancement between the two parts of the switch 81 makes it possible to avoid damaging the push button 85 when the engine is stopped with a delay after detection of the limit clamping position. The push button 85 continues to sink but at low speed. The maximum stroke of the push button 85 can be reduced, then the switch is compact. Alternatively, the controller 61 is configured to stop the motor 50 upon receipt of the information of change of state of the switch 81 when the threaded rod is rotated in the tightening direction. switch 81 makes it possible to avoid damaging the push button 85 when the engine is stopped with a delay after detection of the limit clamping position. The push button 85 continues to sink but at low speed. The maximum stroke of the push button 85 can be reduced, then the switch is compact. Alternatively, the controller 61 is configured to stop the motor 50 upon receipt of the information of change of state of the switch 81 when the threaded rod is rotated in the tightening direction. switch 81 makes it possible to avoid damaging the push button 85 when the engine is stopped with a delay after detection of the limit clamping position. The push button 85 continues to sink but at low speed. The maximum stroke of the push button 85 can be reduced, then the switch is compact. Alternatively, the controller 61 is configured to stop the motor 50 upon receipt of the information of change of state of the switch 81 when the threaded rod is rotated in the tightening direction. switch is then compact. Alternatively, the controller 61 is configured to stop the motor 50 upon receipt of the information of change of state of the switch 81 when the threaded rod is rotated in the tightening direction. switch is then compact. Alternatively, the controller 61 is configured to stop the motor 50 upon receipt of the information of change of state of the switch 81 when the threaded rod is rotated in the tightening direction.

On the non-limiting embodiment of the figures, the sensors 70 and 80 comprise the same actuator 72, which here is a plate extending substantially in a plane perpendicular to the axis x. This abutment 72 common to the two sensors is in engagement with a thread 73 disposed between the other two threads 22 and 23. This embodiment is particularly interesting because it is compact and requires few parts.

Advantageously, the pitch of the third thread 73 engages the abutment 72 is greater than the pitch of the second thread 23. This ensures the approximation of the nut 21 and the stop 72 when the stem is rotated in the clamping direction and their expulsion when the shaft 18 rotates in reverse.

Advantageously, as is the case in the embodiment of Figures, the pitch of the third thread 73 is greater than that of the first thread 22. The combination of the nut 20 and the stop 72 when they move in opposite direction, then fast and allows a stop of traveling to a specific location.

Alternatively, the second portions of the two sensors are different. One can for example provide an abutment by sensor. These second parts can then be taken with different threads of the threaded rod. At least one of the sensors may have a second portion fixed relative to the threaded spindle or at least fixed in translation with respect to the threaded rod. At least one of the second parts is in engagement with a thread disposed outside the space defined by the threads 22 and 23 along the x axis.

Can invert the first portion and the second portion of at least one sensor. For example, the first portion of at least one sensor is an actuator and the second portion of at least one sensor is a push button. the can for example set one or both push-button switches to the nut 24 and fix the actuator corresponding to the nut 20 or 21. the two switches to the nut 21 in the opposite direction with the x axis and providing two stops fixed to the nuts 20 and 21 respectively can for example be set.

In the embodiment of the figures, the sensors 70, 80 are of the type actuator / pushbutton switch. Alternatively, at least one sensor is another type of sensor. This is for example a magnetic sensor, an optical sensor, an inductive-type sensor, a Doppler effect sensor for detecting a variation in distance between two parts of the sensor along the axis x . However, these sensors require treatment to detect the desired position. These sensors can also have a second common portion or second distinct parts. Depending on the case, a sensor may be sufficient.

Advantageously, each sensor, or at least one sensor is configured and arranged to be responsive to a distance variation between its two sides parallel to the x-axis but not to a change of relative angular position between the two parts around the x axis. This makes the adjustment of the sensor insensitive to the angular clearance of the connecting its nut relative to the frame. Furthermore, since only the axial relative movement is taken into account, if the parts of a sensor moving tangentially or radially relative to the rod along the x axis (due to the play of the helical connection), this n ' no importance because their relative distance along the x axis does not vary. The solution is therefore very sensitive to expansion, vibrations, movements,

This is for example the case of the embodiment of Figures, wherein each sensor 70 and 80 comprises a stop 72 extending substantially in a plane perpendicular to the axis x and a push button switch 71 or 81 comprising a push button 75 or 85 in sliding connection with a nut 20 or 21 respectively parallel to the x axis. This solution has the advantage to be compact and simple. It can be performed with push reasonably consistent diameter buttons with aeronautics. Furthermore, this embodiment does not require the installation, as in the prior art, a pivoting ramp so that the drive device accepts without deterioration, an approximation of the fixed part of the switch and stop after closing of the light switch. The nature of the push button this rapprochement. We can therefore dispense with the tedious step and ramp adjustment of the relative position of the ramp and the abutment along the y axis. This is also the case for example of an optical sensor comprising a source emitting a light beam parallel to the axis x, a second portion in the form of a reflecting plate perpendicular to the x axis and a detector for detecting a beam reflected by the plate and measuring a difference of a physical quantity between the incident ray and the reflected ray and deducing a distance between the plate and the source along axis x. a tedious step ramp and adjusting the relative position of the ramp and the abutment along the y axis. This is also the case for example of an optical sensor comprising a source emitting a light beam parallel to the axis x, a second portion in the form of a reflecting plate perpendicular to the x axis and a detector for detecting a beam reflected by the plate and measuring a difference of a physical quantity between the incident ray and the reflected ray and deducing a distance between the plate and the source along axis x. a tedious step ramp and adjusting the relative position of the ramp and the abutment along the y axis. This is also the case for example of an optical sensor comprising a source emitting a light beam parallel to the axis x, a second portion in the form of a reflecting plate perpendicular to the x axis and a detector for detecting a beam reflected by the plate and measuring a difference of a physical quantity between the incident ray and the reflected ray and deducing a distance between the plate and the source along axis x.

Alternatively, the sensor is sensitive to the variation of relative angular position between the two parts around the abutment. For example, the position sensors have an arrangement similar to that of the prior art.

The driving device 15 also comprises a wheel 52, visible in figure 5, integral with the wheel 33 in rotation about its axis of rotation. This knob allows an operator to drive the rod in rotation manually.

Figure 6 shows a schematic kinematic diagram of the driving device. The helical links 220 and 221 between the nuts 20 and 21 respectively and the threaded rod are shown as well as the pivot connections 218 and 340 between the frame 19 and the threaded rod 18 and respectively the wheel 34. It is also noted that the push buttons 75 and 85 are

slides bonds with the fixed parts 74 and 84 of the respective switches. Connections preventing rotation of the nuts relative to the frame are not shown.

Advantageously, as shown in Figure 6, the drive device 15 includes a clutch 54 configured and arranged to remove the torque transmission between the motor 50 and the threaded rod 18 when the torque about the axis of the threaded rod exceeds a predetermined threshold. Advantageously, in addition to the torque limiter 54, the movement transmission device includes a free wheel 55. The torque limiter 54 and the free wheel 55 are configured and arranged to enable the limitation of a rotation torque of the threaded rod 18 about the x axis in one direction of rotation only when the freewheel 55 allows a rotation and thus a shift in the torque limiter. In the other direction, the freewheel does not allow any rotation and the torque limiter can not act. advantageously, the direction of rotation in which the torque limiter acts is the direction corresponding to clamping. This device prevents the tightening torque does not come to exceed a predetermined threshold which is the same whatever the diameter of the antenna. The timer of the clamping motor ensures the sliding of the clutch prior to stopping the engine. However, the torque limiter does not act in the direction of loosening. Limiting the angular travel of the threaded rod in the direction of clamping ensures that an operator or that the motor 50 can tighten the clamping band after loosening the torque limiter acting only clamping. prevent the tightening torque comes to exceed a predetermined threshold which is the same whatever the diameter of the antenna. The timer of the clamping motor ensures the sliding of the clutch prior to stopping the engine. However, the torque limiter does not act in the direction of loosening. Limiting the angular travel of the threaded rod in the direction of clamping ensures that an operator or that the motor 50 can tighten the clamping band after loosening the torque limiter acting only clamping. prevent the tightening torque comes to exceed a predetermined threshold which is the same whatever the diameter of the antenna. The timer of the clamping motor ensures the sliding of the clutch prior to stopping the engine. However, the torque limiter does not act in the direction of loosening. Limiting the angular travel of the threaded rod in the direction of clamping ensures that an operator or that the motor 50 can tighten the clamping band after loosening the torque limiter acting only clamping. the torque limiter does not act in the direction of loosening. Limiting the angular travel of the threaded rod in the direction of clamping ensures that an operator or that the motor 50 can tighten the clamping band after loosening the torque limiter acting only clamping. the torque limiter does not act in the direction of loosening. Limiting the angular travel of the threaded rod in the direction of clamping ensures that an operator or that the motor 50 can tighten the clamping band after loosening the torque limiter acting only clamping.

The motor 50 is coupled to the second wheel 34 through the torque limiter 54 and the potential freewheel 55. The freewheel 55 allows for coupling / uncoupling the two shafts 56 and 57 connected to the frame 19 by links pivot 340 and 341 respectively. A first shaft 56 is secured to the wheel 34 and the other 57 is a shaft of the motor 50.

In the embodiment of the figures, the clamping band 6 forms a closed loop. In other words, the clamping band comprises two web strands 7 and 8 listed in Figure 4, each comprising one of the two ends 10 to 1 1 of the clamping band 6 and intersecting such that a closed loop intended to surround completely the object to be clamped, that is to say to make a complete revolution around the object, is formed by the clamping band 6. the use of a strip 6 forming a closed loop by passing

two band strands allows to vary significantly the size of the loop and thus to grip and release objects having different diameters. Alternatively, the clamping strip 6 does not form a closed loop. In this case its ends are close during tightening and away when loosening. In this case, the two ends approach during tightening and away when loosening. It can then be envisaged to provide second portions, for example stops, distinct for the two sensors into engagement with different threads disposed outside the space delimited by the two threads 22 and 23.

The clamping band 6 comprises for example a metal foil or a plastic band. The perimeter or size of the loop varies, for example, during the tightening, by a variation of the bending of the clamping band. The tape advantageously has a shape at rest as the central portion substantially follows the shape of the perimeter of the object to be clamped.

Strapping 5 also includes pads 14 distributed along the clamping band so as to be intended to be interposed between the clamp band 6 and the object 101 to grip. A pad, not shown here can be supported on the two web strands 7 and 8 so as to be interposed between the two web strands 7 and 8 and the object to be clamped.

The controller 61 may include one or more dedicated electronic circuits or a general purpose circuit. Each electronic circuit may comprise a reprogrammable computing machine (a processor or a microcontroller, for example) and / or a computer executing a program comprising a sequence of instructions and / or a dedicated computing machine (e.g., a set of logic gates as a FPGA a DSP or ASIC or other hardware module).

The drive device according to the invention can be integrated into another type of holding device 350 as shown in Figure 7 of the type comprising two flanges 310 and 320 to maintain or release an object. For clarity, shows only the threaded rod (without the third thread), nuts, flanges and the bars 312, 313 but the drive device is a drive device according to the invention. Insoles 310 and 320 are respectively fixed in translation along the x axis to the nut 20 and the nut 21 via rods 312 and 313 respectively which intersect. When the rod 18 rotates in one direction the nuts 20 and 21

approach each other and the flanges 310, 320 move apart so as to come into abutment on a hollow body 314, for example, cylindrical section, inside the hollow body so as to exert forces in opposite direction parallel to the axis x, for example opposite, on the hollow body for clamping the body. These efforts are preferably radial, in a same radial axis defined for a circular section of a hollow body. When the threaded rod 18 rotates in the opposite direction, the nuts move away and soles approach so as to deviate from the hollow body and to release it. Alternatively, the soles of the traveling direction is the one of the nuts. For example, the bars 312 and 313 do not cross. For clarity, only the two threads 22 and 23 of the threaded rod are shown in Figure 7. The other elements of the driving device are not shown sensors, and the third thread are not shown in Figure 6 for clarity. Advantageously, the torque limiter 54 and the possible free wheel 55 are arranged to enable the limitation of a rotation torque of the threaded rod 18 about the axis x in a direction of rotation, and possibly only in this direction. This rotation direction is the direction corresponding to clamping, that is to say the direction of rotation causing the distance between the two flanges and thus bringing the two nuts. possible free wheel 55 are arranged to enable the limitation of a rotation torque of the threaded rod 18 about the axis x in a direction of rotation, and possibly only in this direction. This rotation direction is the direction corresponding to clamping, that is to say the direction of rotation causing the distance between the two flanges and thus bringing the two nuts. possible free wheel 55 are arranged to enable the limitation of a rotation torque of the threaded rod 18 about the axis x in a direction of rotation, and possibly only in this direction. This rotation direction is the direction corresponding to clamping, that is to say the direction of rotation causing the distance between the two flanges and thus bringing the two nuts.

CLAIMS

1. A drive device comprising:

- a frame (19),

- a screw-nut system comprising a threaded rod (18) and a first nut (20) in helical connection with the threaded spindle (18), the threaded rod (18) being connected to the frame (19) by a pivot connection (218 ) for the threaded rod (18) from rotating relative to the frame (19) about a longitudinal axis (x) of the threaded rod (18),

- a first position sensor (70) for detecting a first limit position of the nut (20) along the longitudinal axis (x), the first position sensor (70) comprising a first portion (71) and a second portion (72), the first position sensor (70) being responsive to a variation in a distance between the first portion (71) and the second portion (72) of the first sensor position along the axis (x) ,

the first portion (71) being fixed to the first nut (20) and the second part (72) being linked to the threaded rod (18) without passing through the pivot link (218) and such that rotation of the threaded rod ( 18) about the longitudinal axis (x) results in a distance variation between the first portion (71) and the second portion (72) of the first position sensor (70) along the longitudinal axis (x).

2. A drive device according to the preceding claim, wherein the second portion (72) of the first sensor (70) is helically connected to the threaded rod (18).

3. Drive device according to any one of the preceding claims, wherein the screw-nut system comprises a second nut (21) in helical connection with the threaded spindle (18), the first nut (20) being engaged with a first thread (22) of the threaded rod (18) and the second nut (21) being engaged with a second thread (23) of the threaded rod (18), the first thread (22) and the second thread (23 ) being formed in opposite direction, the drive device comprising a second position sensor (80) for detecting a second limit position of the nut (21) along the longitudinal axis (x) relative to the frame (19) , the second position sensor (80) comprising a first portion (81) and

a second portion (72), the second position sensor (80) being responsive to a variation in distance between the first portion (81) and the second portion (72) of the second position sensor along the axis (x) , the first portion (81) of the second position sensor (80) being fixed to the second nut (21) and the second portion (72) of the second position sensor (80) being linked to the threaded rod (18) without passing through the pivot link (218) and such that rotation of the threaded rod (18) about the longitudinal axis (x) results in a distance variation between the first portion (81) and the second portion (72) of the second sensor position (80) along the longitudinal axis (x).

4. Drive device according to the preceding claim, wherein the first thread (22) and the second thread (23) have an even called first step.

5. Drive device according to any one of claims 3 to 4, wherein the second portion (72) of the second sensor (80) is helically connected to the threaded rod (18).

6. Drive device according to the preceding claim in that it depends on claim 2, wherein the second portion (72) of the two sensors (70; 80) is engaged with one additional thread (73).

7. Drive device according to claim 6, wherein the second thread (23) has a second step, the additional thread (73) being formed in the same direction as the second thread (23) and has a third pitch different from the second step (23).

8. Drive device according to claims 4 and 7, wherein the additional thread (73) is interposed between the first thread (22) and the second thread (23) and has a third step higher than the first step.

9. Drive device according to any preceding claim, wherein the first portion (71) and the second portion (72) of the first sensor (70) comprises a push button switch (71, 81) and an actuator (72) for actuating a push button (75) of the push button switch to cause a change of state of the switch.

10. Drive device according to any preceding claim, wherein the first position sensor (70) is configured to be responsive to a variation in distance between the first part and the second part along the x axis but not to a variation in relative angular position between its first part and its second part around the x axis.

January 1. Drive device according to claim 10 in that it depends on claim 9, wherein the pushbutton (75) is connected to slide parallel to the longitudinal axis (x) with a fixed part (74) of the switch and the stop (72) extends in a plane substantially perpendicular to the longitudinal axis (x).

12. Drive device according to any one of the preceding claims, comprising a motor (50) coupled to the threaded rod (18) for driving the threaded rod (18) in rotation about its longitudinal axis (x) .

13. Drive device according to the preceding claim, comprising a controller (61) for controlling the motor (50), the controller (61) receiving the measurements from the first position sensor and being adapted to control the motor (50) from the measurements.

14. Drive device according to the preceding claim and according to claim 8, wherein the controller receives measurements from the second position sensor (80), the controller (61) configured to stop the engine ( 50) upon detection of the limit position of the first nut (20) when the threaded rod (18) rotates in a first direction, and with a delay after detection of the boundary position of the second nut (21), when the threaded rod (18 ) rotates in the opposite direction.

15. Strapping device (4) for encircling an object by means of a strap (5) comprising a clamping band (6) comprising a first end (10) and a second end (1 1) and forming a loop for to surround the object, the strapping apparatus comprising a drive device according to any one of the preceding claims, for moving the two ends relative to each other to enlarge or reduce the size of the loop, the first end (10) of the hoop (6) being integral with the first nut (20) in translation along the axis of the threaded rod (8).

16. A strapping machine according to the preceding claim, wherein the drive device is a drive device according to claim 3 and wherein the second end is integral with the second nut (21) in translation along the axis of the stem threaded (18).

17. A strapping machine according to any one of claims 15 to 16, wherein the loop is closed.

18. A holding device for clamping a hollow object, said device comprising a first flange and a second flange adapted to abut on a hollow object, inside the hollow object, the holding device comprising a device drive according to any one of claims 1 to 14, the drive device being configured to move the two flanges relative to one another so as to separate them from one another to grip the object or together to release the object, the insole being integral with the first nut in translation along the axis of the threaded rod (18), the screw-nut system comprising a second nut engaged with a second thread made in opposite direction of the first thread,the second flange being integral with the second nut in translation along the axis of the threaded rod (18).