The present invention relates to drive devices for screw-nut system. In such mechanisms, rotation of a threaded rod causes translation of a nut coupled to the threaded shaft by a helical connection along the longitudinal axis of the rod.

Such mechanisms are implemented notably in detection devices for helicopter fight against underwater threats in which an antenna for detecting underwater threats is suspended from an aerial platform such as an aircraft allows to immerse 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 and the electrical energy necessary for the acoustic emission 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 according to the z axis and 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

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. This strapping device 104 locks the position of the antenna 101 with respect to the winch 100 so as to prevent accidental fall of the antenna and its consequences.

known banding devices comprise a clamping strip forming a loop intended to encircle or surround the antenna 101 and a movement device for driving the screw-nut system type enabling to reduce the size of the loop, at step said clamping or increase the size of the loop at a said step of loosening, so as to grip the antenna 101 or respectively the loosening to release it. Each end of the clamping band is in engagement with a thread of the threaded spindle in translation along the threaded rod. The nuts are made with threads made in the opposite direction so that the clamping and unclamping are performed by moving the ends of the clamping band in the opposite direction along the longitudinal axis of a threaded rod. The

It should prevent the loop size to exceed a maximum size or go below a certain minimum size.

In order to block the stroke of the nuts, the Applicant has envisaged in the context of the present invention to install stops, each stop being installed in the path of one of the nuts along the axis of the threaded rod in a direction (tightening or loosening). The movable nut in translation with respect to a stop along the axis of the threaded rod, is approaching the abutment when the release operation to abut against it which will block the translational movement of nut with respect to the stop and thus stop the enlargement or loop size reduction formed by the clamping band.

However, this type of solution can lead to jamming of the strapping. Indeed, when the nut bears against the abutment, clamping takes place in the thread between the threaded rod and nut. A large torque is necessary to loosen the nut of the threaded rod in order to release the contact between the nut and the stop. This pair may be excessive if the tightening of the nut against the stop is too great. For example, an operator may be able to cause the threaded rod in rotation until a nut comes into abutment in one direction against a stop but torque to be applied on the threaded rod to provide a flashback may be too much for the engine or another operator. Moreover, a bind can always intervene between the screw and nut,

An object of the invention is to provide a drive device comprising a system of screw-nut type which allows to block the stroke of the nut relative to the threaded spindle in one direction without leading to a clamping position of the nut relative to the threaded rod.

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

- a screw-nut system comprising a first threaded rod and a nut connected to the threaded rod by means of a helical connection,

- a gear for transmitting a rotation to the threaded rod, a first gear and a second gear engaged with the first gear,

-a set of abutments comprises a first stop connected to the first wheel to rotate about an axis of rotation of the first wheel and a second stop connected to the second gearwheel in rotation about an axis of rotation of the second wheel the first stop and the second stops being configured and arranged to bear one on the other so as to limit an angular travel of the threaded rod in a first angular position in a first direction.

In one embodiment, the first stop and the second stop are configured and arranged to bear one on the other so as to limit the angular travel of the threaded rod to a second angular position in a second direction opposite to the first direction.

In another embodiment, the set of abutments comprises a third stop connected to the first wheel to rotate about the axis of rotation of the first wheel or bonded to the second gear in rotation about the axis of rotation of the second wheel and configured and arranged to bear against the second stop, or respectively on the first abutment, for limiting the angular travel of the threaded rod to a second angular position in a second direction opposite the first direction.

In another embodiment, the set of abutments comprises an additional first abutment connected to the second gear in rotation about the axis of rotation of the second wheel and a second additional stop linked to the first rotating wheel around the axis of rotation of the first wheel, the first additional and second additional abutment stop being configured and arranged to bear one on the other so as to limit an angular travel of the threaded rod to a second angular position in the second direction opposite the first direction.

The device advantageously includes at least one of the following features taken alone or in combination:

- the first gear has a first number of teeth and the second toothed wheel has a second different number of teeth of the first number of teeth,

- the first number of teeth and the second number of teeth are coprime,

- at least one stop of the set of stops capable of occupying a plurality of predetermined fixed angular positions,

relative to the wheel to which it is coupled in rotation, about the axis of rotation of the wheel,

- at least one stop is removably mounted on the first wheel or the second wheel at an angular position taken from a plurality of angular positions,

- it comprises a motor coupled to the threaded shaft and for driving the threaded rod in rotation around the longitudinal axis,

- the threaded rod is coupled to the motor via a torque limiter,

- the rod is coupled to the motor via a torque limiter and a freewheel configured to allow limiting a torque of the threaded rod about its longitudinal axis in one direction of rotation only,

- it comprises a control member and at least one sensor for detecting a first maximum operational angular position of the threaded rod in the preceding first direction the first rotational position in the first direction, the controller receiving measurements from the first position sensor and being configured to control the motor from the sensor measures to stop the engine when the first limit angular position is reached,

- it comprises a knob integral with a toothed wheel of the gear enabling an operator to rotate said gear about an axis of rotation of said toothed wheel.

The invention also relates to a banding device for encircling an object comprising a clamping band comprising a first end and a second end and forming a loop intended to surround the object, the strapping apparatus comprising a driving device according to any one of the preceding claims, wherein the drive device 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 translation along the axis of the threaded rod.

Advantageously, the first nut is in engagement with a first thread of the threaded shank, the screw-nut system comprising a second nut engaged with a second thread of the threaded rod directed in opposite direction of the first thread, the second end of the strip clamp being integral with the second nut in translation along the axis of the threaded rod.

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 within the object, the device of maintenance comprising a drive device according to the invention, configured to move the two flanges relative to one another so as to separate them from each other 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 of the 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 schematically shows a strapping apparatus of the invention comprising a driving device according to the invention,

- Figures 3a to 3c show a gear of a drive device according to a first embodiment in a locking configuration in a first direction (3a and 3b in perspective front view and in a locking configuration in a second opposite direction (Figure 3c in front view),

- Figures 4a and 4b show schematically, in front view, a gear of a drive device according to a second embodiment in a locking configuration in a first direction (Figure 4a) and in a locking configuration in a second opposite direction (Figure 4b),

- Figures 5a and 5b show schematically, in front view, a gear of a drive device according to a third embodiment in a locking configuration in a first direction (Figure

5a) and in a locking configuration in a second opposite direction (Figure 5b),

- Figure 6 shows simplified kinematic diagram of the driving device according to the invention,

- 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 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 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, but may be different.

The drive device can drive in translation at least one nut relative to the threaded rod along the longitudinal axis of the threaded rod.

The driving device can be used for devices other than strapping devices which require such a conversion of a rotational movement into a translational movement. 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 to limit the set of displacement.

As shown in Figure 2, the strapping device 4 comprises a strapping 5 adapted to encircle an object, for example an antenna 101 and specifically its protective structure 1 13. The strapping device makes it possible to grip or release the object, here the antenna 101. Strapping 5 comprises a clamping strip 6 forming a loop intended to surround the object. The clamping band 6 comprises two longitudinal ends 10 and 1 1.

The strapping device 4 also comprises a clamp / release 15 for moving the longitudinal ends

In 10 and 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, during a step called clamping 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 causes a pressure on the object to grip 101 and creates an interference fit between the rim 5 and the object 101. To maintain the tightness of the object 101,

The clamp / release 15 is a drive device according to the invention.

The clamp / release 15 comprises a screw-nut screw system 17 comprising a threaded rod 18 and at least one nut 20. The threaded rod 18 is linked to a frame 19 by a pivot connection 218 seen in Figure 6 to be described later , allowing the threaded rod to rotate relative to the frame 19 about the longitudinal axis x of the threaded rod 18.

The screw-nut system 17 comprises a first nut 20 in helical connection with the threaded rod 18 and connected to the frame 19 by a bond preventing the nut from turning about the axis x. Thus, the nut 20 moves in translation relative frame 19 along the x axis. The screw-nut system 17 also includes a second nut 21 in helical connection with the threaded rod 18 and connected to the frame 19 by a bond preventing the nut from turning about the axis x. Thus, the nut 21 moves in translation relative frame 19 along the x axis. As shown in Figure 2, the first nut 20 is engaged with a first thread 22 of the threaded rod 18 and the second nut 21 is engaged with a second thread 23 of the threaded rod 18. The first thread 22 and second thread 23 are formed in opposite directions 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 along the x axis and end 1 1 is integral with the nut 21 in translation along the x axis. Therefore, the screw-nut system allows

move the two ends of the clamping band 10 to 1 1 in the opposite direction and at the same speed, if the steps are identical, relative to the threaded rod 18 and the frame 19, parallel to the axis of the threaded rod 18 during the clamping operation (when the rod rotates in one direction around the x axis) and released (when the rod rotates in the opposite direction).

The end 10 or 1 1 may be integral with the nut 20 or 21 (fixed to the nut or integral with the nut) or pivotally connected to the nut 20 or 21 about an axis substantially perpendicular to the x axis and substantially perpendicular to the plane of the clamping band 6 (the loop plane).

In the embodiment of the figures, the screw-nut system 17 comprises two nuts 20 and 21 each connected at one end 10 and, respectively, 1 1. Alternatively, the screw-nut system comprises a single helical connection nut with the threaded rod 18 and integral with one end 10 or 1 1 in translation relative to the frame along the x axis. The other end is for example fixed to the frame 19.

The drive device 15 comprises a gear 30 for transmitting a rotary movement to the threaded rod 18. The gear 30 includes a first gear 33 and second gear 34 engaged with the first gear wheel 33. These wheels toothed adjoin. The wheel 33 is coupled to the threaded rod 18 to allow the transmission of a wheel rotational motion 34 about an axis of rotation p of the wheel 34 via the gearwheel 33, the threaded rod 18. The wheel 33 is the driven wheel and the wheel 34 is the drive wheel. The threaded rod 18 rotates about its longitudinal axis x. The two toothed wheels 33 and 34 rotate in opposite directions about their respective axes of rotation.

In the embodiment of Figure 2, the gear 30 includes only two gears 33 and 34 and their axes of rotation are parallel to the axis of rotation x of the threaded rod 18. Alternatively, the gear 30 includes more than two toothed wheels and the wheel rotation axes are not necessarily parallel to the longitudinal axis of the threaded rod 18.

According to the invention, the drive device 15 comprises a stroke limiter for limiting an angular travel of the threaded rod 18 about the axis x. Consequently the stroke limiter makes it possible to limit the travel of the nuts along the x axis. The stroke limiter comprises a set of abutments comprises a first stop 31 and second stop 32 arranged to bear one on the other so as to limit the angular travel of the threaded rod 18 in a first rotational direction around the x-axis.

This prevents further rotation of the threaded rod 18 in the first direction of rotation. The rod 18 is locked in a first angular position about the axis x. The relative movement of the two ends 10 to 1 1 and the enlargement or reduction of the size of the loop formed by the strap 5 are then blocked. In summary, the solution provided is to equip the screw-nut system 17 of two end stops, solid periodic antagonists which will be in confrontation after a certain angular stroke (number of revolutions) of the threaded rod around the x-axis in a direction of rotation. This solution has the advantage of avoiding jamming of the movement conversion mechanism and thus strapping. Indeed, with this type of stops, after blocking of rotation of the threaded rod in the first direction of rotation, it is possible to rotate in the other direction without any resistance. This purely mechanical solution is reliable and fully reversible.

If the two wheels 33 and 34 have the same number of teeth, the two stops are coming to bear on each other substantially at the end of a turn of a wheel 33 or 34. The angular travel of the threaded rod is limited to one turn if the wheel 33 is integral with the threaded rod 18. This has the consequence of limiting the amplitude of variation of diameter of the loop. The strapping device will therefore be able to operate for a range of objects or diameter antennas 101 limited.

Advantageously, the number of teeth of the wheel 33 is different from the number of wheel teeth 34. Thus, it is possible to configure the two stops 31, 32 so as to allow a stroke of the threaded rod 18

corresponding to an angular stroke of more than one turn of one of the wheels 33 or 34. The relative position of the two stops 31, 32 will change at every turn. It is then possible to increase the amplitude of variation of diameter of the loop.

Advantageously, the wheels of the numbers of teeth 33 and 34 are coprime. Their greatest common divisor GCD is 1. This configuration allows to allow a significantly higher angular travel of the threaded rod 18. The variation of the distance between the two ends of the hoop 10 to 1 1 and thus the variation in the diameter of the loop is then maximal.

Preferably, the wheel with the smallest number of teeth, here the first wheel 33 is the driven wheel. In other words, it is coupled to the threaded rod 18 so that they have the same angular displacement about their respective axes of rotation. This provides a maximum angular travel of the threaded rod 18.

In the embodiment of the figures, the wheel 33 and the shaft have the same rotational axis. Alternatively, the wheel 33 has a different axis of rotation of the threaded rod. The wheel and the threaded spindle are coupled for example by means of a transmission joint such as a universal joint or Oldham joint. Alternatively, the axis of rotation of the wheel 33 is different from the x axis and the toothing of the wheel 33 cooperates with the thread of the threaded rod 18, for example by means of another toothed wheel to rotate it.

Advantageously, as shown in Figures 3a to 3c, the stop 31 and the stop 32 are configured (in shape and dimensions) and arranged to bear one on the other so as to limit an angular stroke of the rod 18 threaded in a first extreme angular position, around the x axis, when the threaded rod rotates in a first rotational direction about its axis x. In the example of the figures, the threaded rod being integral with the wheel 33, this direction of rotation is that of the wheel 33 shown by an arrow in Figure 3b. The stops 31 and 32 then occupy a first relative position shown in Figure 3b. The stops are also configured and arranged to bear one on the other in a second relative position (shown in Figure 3c) for restricting the rotation of the threaded rod to a second end angular position when the threaded rod 18 rotates in a second direction opposite the first direction. This second meaning

rotation is represented by the arrow showing the direction of rotation of the wheel 33 in Figure 3c. In other words, in the nonlimiting example of FIG 3, the stops 31, 32 are arranged to block the strapping 5 for operational maximum size of the loop (minimum distance between the ends 10 to 1 1 obtained when the threaded rod occupies the first extreme angular position) and to an operational minimum size of the loop (maximum distance between the ends 10 to 1 1 obtained when the threaded rod is second extreme angular position).

We note 1 ( the number of wheel teeth 33 and z 2 is the number of teeth of the wheel 34 with z i other than z 2 .

GCD is the greatest common divisor between zeta gamma and z 2 ,

is the number of wheel turns 33 between the first relative position between the stops (Figure 3b) and the second relative position between the stops (Figure 3c), that is to say between the first extreme angular position and the second extreme angular position in the second direction, and n 2 is the number of wheel turns 34 between the first relative position and the second relative position.

So: No, 1 = - GCD π = n 2 * - Z 1 and n 2 = - GCD - π.

where a is the angle formed, in the first relative position between the line connecting the fulcrum P, between the abutment 31 and the abutment 32 and the center C1 of the wheel 33 and the line connecting the centers C1 and C2 of the two wheels 33 and 34. β is the angle formed between the straight line connecting the fulcrum P between the abutment 31 and the abutment 32 in the first relative position, the center C2 of the wheel 34 and the line connecting the centers C1 and C2 of the two wheels 33 and 34. in Figure 3c, the supporting point P 'between the two stops 31 and 32 is symmetrical to the point P with respect to the right C1, C2.

The angular travel of the threaded rod 18 between its first angular end position and its second extreme angular position in the second direction of rotation by the angular stroke of the wheel 33. By

Therefore, the maximum number of revolutions of the rod 18 is which is close to the number of teeth of the driving wheel 34.

In the following text, the term first extreme angular position and second extreme angular position, the angular positions of the threaded rod in which it is blocked by the stops in the two respective directions. The values ​​of these angular positions vary among embodiments according to the configuration of the stops.

In a variant shown in Figures 4a and 4b, the gear 130 includes two toothed wheels 33 and 34. It includes the abutments 31 and 32 and a third abutment 35 rotationally connected to the wheel 34 around the axis of rotation of the wheel 34. Advantageously, the third abutment 35 is arranged to bear against the first stop 31, when in a relative position shown in Fig 4b, to limit the angular travel of the threaded rod 18 to the second extreme angular position in the second direction opposite the first direction. In other words, the stops are arranged such that when, starting from its second extreme angular position, it rotates in the first rotational direction, while the stop 31 comes from first bearing against the stop 32 (as shown in Figure 4a) for limiting the angular travel of the threaded rod 18 in the first direction. It is then in a first extreme angular position. The stops 31, 32, 35 are also arranged so that, starting from the first extreme angular position, the threaded rod 18 starts to rotate in the second direction of rotation, it bears on the abutment 35, before encountering the stop 32. in other words, when starting from its first angular position, the threaded shaft 18 begins to rotate in the second rotational direction, it is blocked by the stop 35 and can not reach the second stop 32. It is thus possible to reduce the angular travel of the threaded rod 18 and therefore the variation in distance between the ends 10 to 1 1 and the variation of the loop size. It is then in a first extreme angular position. The stops 31, 32, 35 are also arranged so that, starting from the first extreme angular position, the threaded rod 18 starts to rotate in the second direction of rotation, it bears on the abutment 35, before encountering the stop 32. in other words, when starting from its first angular position, the threaded shaft 18 begins to rotate in the second rotational direction, it is blocked by the stop 35 and can not reach the second stop 32. It is thus possible to reduce the angular travel of the threaded rod 18 and therefore the variation in distance between the ends 10 to 1 1 and the variation of the loop size. It is then in a first extreme angular position. The stops 31, 32, 35 are also arranged so that, starting from the first extreme angular position, the threaded rod 18 starts to rotate in the second direction of rotation, it bears on the abutment 35, before encountering the stop 32. in other words, when starting from its first angular position, the threaded shaft 18 begins to rotate in the second rotational direction, it is blocked by the stop 35 and can not reach the second stop 32. It is thus possible to reduce the angular travel of the threaded rod 18 and therefore the variation in distance between the ends 10 to 1 1 and the variation of the loop size.

I 2 , less than z 2 is the number of intervals between two adjacent teeth between the stops 32 and 35 of the wheel 34, the number of intervals being counted starting from 32 to 35 in the direction of rotation of the wheel 34 when the latter rotates to move from the stop position 32 of 31 to the stop position 35 on 31.

When the wheel 33 comprises an abutment 34 and the wheel comprises two stops, then the number n 3 of the wheel 33 turns about its axis between two extreme angular positions of the threaded rod is:

When, starting from the first extreme angular position in which the stops 31 and 32 are in abutment on each other, the threaded rod 18 starts to rotate in the second direction and just meets the stop 35 before meeting again the stop 32, thereby blocking the rotation of the rod 18 in the second direction, then:

r I2 + s * Z2 ) a

n3 = min \s £ N | £ N

Z l 2 - Z i ) p

If stop 31 is not blocked by the stop 35 before the stop 32 in the second direction, then:

_ Z2 a

Us ~ PGDC ^ iZ Zz) π

It is possible to adjust I 2 to achieve the desired n1.

Thus, with two toothed wheels 37 and 39 teeth, one of the wheels having a single stop and the other two abutments arranged at 26 teeth apart, are allowed approximately 13 rounds of the threaded rod with a stop to the other because at every turn, the relative position of the stops varies from 2 teeth.

To find I 2 according to Z 1; Z 2 and ¾:

I 2 = min {s £ N | (n + * (Z 2 - ZJ - s * Z 2 £ N j

Alternatively, the stop 35 is connected to the toothed wheel 33 in rotation about the axis of rotation of the wheel 33. It is arranged to bear against the stop 32 to prevent rotation of the threaded rod 18 in the second direction when the threaded rod 18 occupies the second extreme angular position.

In a variant shown in Figures 5a and 5b, the gear 230 includes two wheels 33 and 34. The stops 31 and 32 are

other so as to limit the angular travel of the threaded rod 18 to a second extreme angular position in the second direction. In other words, the locking of the threaded rod is done by help of two stops 31, 32 one on the other in one direction and by support of two stops 36, 37 one above the other in the other meaning. The abutments are configured and arranged to allow the threaded rod to move from its first extreme angular position to its second extreme angular position in the first direction and vice versa in the opposite direction. This solution allows to adjust more accurately the angular travel of the threaded rod 18 between the two locking positions. In solutions with 2 or 3 stops, it is possible to obtaining numbers of wheel revolutions 33 in 1 turn with the angular offset α / Π. The fourth stop to adjust the number of turns with greater accuracy. Positioning and configures the stops relative to each other according to the desired angular stroke for the threaded rod, numbers of teeth of the two wheels and the angles among the stops and the axis between the wheels centers in blocking relative positions.

I 3 , less than z 2 is the number of intervals between two adjacent teeth between the stops 32 and 36 of the wheel 34, the number of intervals being counted starting from 32 to 36 in the direction of rotation of the wheel 34 when it rotates to move from the stop position 31, 32 against the stop 36 in position against 37.

I 1; less than z is the number of intervals between two adjacent teeth between the stops 31 and 37 of the wheel 33, the number of interval being counted starting from 31 to 37 in the direction of rotation of the wheel 34 when the latter rotates to move from the stop position 31, 32 against the stop 36 in position against 37.

The number n 4 of wheel 33 turns about its axis between two extreme angular positions of the threaded rod when the two wheels each comprise two stops is then:

n 4 = A when it is supported by abutments 31 and 32 one on the other, which blocks the rotary movement of the stem in both directions. n 4 = B when it is supported by abutments 31 and 32 one on the other, which blocks the rotation of the threaded rod in the first direction and the support of the stops 31 and 36 one on the another blocking the rotation of the rod in the other direction. n 4 = C when it is supported by abutments 31 and 32 one on the other, which blocks the rotation of the threaded rod in the first direction and the support of the stops 32 and 37 one on the another blocking the rotation of the rod in the other direction. n 4 = D when it is supported by abutments 31 and 32 one on the other, which blocks the rotation of the threaded rod in the first direction and the support of the stops 36 and 37 which block the rotation of the rod in the other direction.

To set the stops, determine first I x from the value n 4 sought:

I1 = Z1 * min \ s E N \ n4— s≥—
Then I set 3 :

I3 = min { s 6 iV | ( n4 + ^ - - * (Z2 - ZJ + (1 - s) * Z2 - It 6 N }

It is not possible, however, for two values Z 1 and Z 2 data, configure all values of n 4 e (se ^ | s - -) as there can

Zi J

be a meeting of the stops 36 on 31 or 32 of 37 prior to the meeting of the stop 36 on the stop 37. It is therefore necessary to check by using the formula given above n 4 = min (A, B, C, D ).

On the embodiments of FIGS, the stops are superimposed lugs in the toothing of a wheel. Is referenced the toothing 38 of the first wheel 33 and the toothing 39 of the second wheel 34 only in Figure 3a.

In the embodiment of the figures, the second stop 32 is superimposed on one of the teeth of the second wheel 34 and has a section the same shape and size of a tooth of the wheel 34 in a plane perpendicular to the axis of rotation of the wheel 34.

The first stop 31 has a support surface S, forming, in a plane perpendicular to the x axis of the first wheel, substantially the shape of a circle portion substantially superimposed on the circle of larger diameter defining the teeth of the toothed wheel and having a substantially equal angular aperture at the opening of a tooth to an adjacent tooth of the wheel 33 about the axis of rotation of the wheel 33. the two stops 31 and 32 extend to the same position along the longitudinal axis of the threaded rod 18. Thus the radial end of the second stop 32 comes into contact with the support surface S of the first stop when they find one opposite the 'other. Such cooperation allows in the case of Figure 3a, a support in the same place of each of the two stops in both directions because of the symmetry of the two stops with respect to radial planes each including the axis of rotation of the corresponding wheel. The stop 31 forms with the axis C1 -C2 an angle a and the stop 32 forms with the axis C1 -C2 an angle β when in the second relative position.

Alternatively, at least one of the stops is asymmetrical with respect to a radial plane containing the axis of rotation of the wheel. In this case, the stops 31 and 32 form different angles a and β respectively when in the second relative position.

The stops are positioned so that the angles a and β of the fulcrum between the two stops are non-zero so that the stops provide the rotational locking.

It is possible to broaden at least one of the stops so as to broaden the contact area between the stops and pressure. The angular travel is reduced.

Advantageously, the maximum radial distance of each stop to the axis of rotation of the wheel to which it is secured is substantially equal to the radius of the tip circle of the toothed wheel. Generally, the sum of the radial distances up on two stops for cooperating for locking in one direction is greater than or equal to the distance between the two wheels, otherwise there would not touch.

Each stop is linked to a rotating wheel around the axis of rotation of the wheel. The abutment is advantageously secured to the wheel in rotation around the axis of rotation of the wheel.

Advantageously, each stop is secured to the corresponding wheel. In other words, it is fixed relative to the corresponding wheel.

The stops may be integral with the toothed wheels or fixed to the sprockets.

In one embodiment, the stops are likely to occupy a single angular position relative to the corresponding wheel about its axis of rotation. They are then fixed for example by fitting the corresponding or respective wheels are one-piece with the corresponding respective wheels or permanently attached to them. Thus the angular stroke adjustment of the threaded rod 18 or its extreme angular positions is done by building during installation of the two wheels 33 and 34 on the frame 19 by selecting the angular positions of the two wheels 33 and 34 depending abutments on the positions of the gears.

Alternatively, at least one stop of the set of stops capable of occupying a plurality of predetermined fixed angular positions with respect to the corresponding wheel 33 or 34 around the axis of rotation of the wheel. In other words, the fixed position of the stop considered with respect to the wheel in question is adjustable. It is possible to come and set by adjusting the position of one or more stops, after assembly of the gearwheels. The angular stroke of the rod may then be adjusted according to the needs in terms of amplitude variation of the size of the loop and / or operational maximum size and / or operational minimum size desired, once after assembly of wheels on the frame. The stop may be mounted on the corresponding wheel by means of a device indexing for adjusting its angular position relative to the wheel about the axis of rotation of the wheel. The mechanical connection for indexing can be achieved, either by positioning pin, by screwing, by keying or other means.

Advantageously, at least one of the stops is releasably fixed to the corresponding wheel and is capable of occupying a plurality of predetermined fixed angular positions with respect to the corresponding wheel about the axis of rotation of the wheel. The amplitude of variation of the size of the loop and / or the operational minimum size and the maximum operational size of the loop can be adjusted after mounting the wheels by positioning the releasable abutment on the wheel in question.

Advantageously, the drive device 15 comprises, as shown in Figure 6, a motor 50 for driving the screw shaft 18 in rotation about the x axis. The motor 50 can drive the wheel 34 in rotation about its axis. The gear 30 transmits this movement to the threaded spindle via the wheel 33. The motor 50 is for example coupled to the wheel 34 through an unillustrated reduction gear.

The driving device 15 also comprises a wheel 52 coupled to the second wheel 34. The wheel 52 allows an operator to rotate the second wheel 34 about its axis p. In this case upon manual actuation of the wheel, the torque imparted by the operator is transmitted to the threaded rod by means of the gearwheels 34, 33 and the gear 51 and the motor 50 are inert. Alternatively the wheel 52 is rotationally connected to the first wheel 33.

Advantageously, the device 15 includes a clutch 54 configured and arranged to suppress the transmission of torque between the threaded rod 50 and the motor 18 when the torque about the axis of the threaded rod exceeds a predetermined threshold.

Advantageously, the device 15 comprises a torque limiter 54 and a freewheel 55 configured and arranged to enable the limitation of a rotation torque of the threaded rod 18 about the axis x in a direction of rotation only when the free wheel 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, this rotation direction is the direction corresponding to clamping, that is to say the direction of rotation causing the distance between the two ends 10 and 1 1 from each other. This device prevents the tightening torque does not come to exceed a predetermined threshold which is the same whatever the diameter of the antenna. However, the torque limiter does not act in the direction of loosening. The stop system according to the invention is perfectly compatible with the torque limiter.

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. The pivot links 218 and 340 between the frame 19 and threaded rod 18 and wheel 34 respectively are also shown. Connections preventing rotation of the nuts relative to the frame are not shown.

The motor 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, 57 connected to the frame 19 by hinge joints 340, 341. A first shaft 56 is secured to the wheel 34 and the other 57 is a motor shaft 50. The stops 31, 32 and the motor 50 are connected by the torque limiter 54 and the freewheel 55. This prevents a disturbance of the position of the stops relative to the position of the strapping obtained in a variant in which the first gear 33 is coupled to the threaded shaft 18 via the torque limiter 54 and the freewheel 55.

Advantageously, the abutments are configured and arranged to prevent relative rotation of the two gears when the motor rotates at full speed without the stops being damaged. In other words, the abutments are configured and arranged to withstand without damage, a sudden stop at a maximum speed of the motor.

Advantageously, the relative stops are configured to prevent rotation of the two gears to a predetermined maximum torque applied to the x axis of the threaded rod 18 without the stops being damaged. This torque is advantageously greater than the maximum torque applied by an operator to grip that would force the dial.

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 2 each having one end in 10 and 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 crossing two band strands possible to vary the size significantly from the loop and thus to grip and release objects having different diameters. Both ends 10 and 1 out of 1 away from each other, like nuts, according to the x axis when the clamping and move towards one another, as the nuts, along the x axis when loosening. Alternatively, the loop is open.

Advantageously, as shown in Figure 6, the drive device 15 comprises a control member 61. It also includes one or more position sensors 70, 80, visible in Figure 2, set (s) for detecting a minimum limit of the loop size greater than the operational minimum size of the loop in the direction of tightening and / or a maximum size limit of the loop below the operational maximum size of the buckle in the loosening direction. In other words, more generally, it comprises at least one sensor for detecting a first angular limit position of the threaded rod in the first direction above the first extreme angular position in the first direction of rotation and / or at least one sensor (which may be identical or different from the sensor ) for detecting a second angular limit position of the threaded rod in the second direction the previous second extreme angular position in the second direction of rotation. The

The position sensors 70, 80 are advantageously sensitive to a relative distance variation between the two ends 10 to 1 1 according to the axis x. On the non-limiting example of Figure 2, the sensors each comprise a push button switch 71 and respectively 81 respectively attached to the nuts 20 and 21 and an actuator 72, which here is common to both sensors and designed as a stop. The stop 72 is disposed between the two nuts 20 and 21, is secured to a nut 24 in helical connection, by means of a helical connection 223 shown su Figure 6, with the rod 18, fixed in rotation about the axis x relative to the frame 19 engages with a third thread 73 realized in the same direction as the thread 23 having a pitch greater than the pitch of the thread 23. The sensor 70 is configured and arranged to move from a closed configuration to open or vice versa when the end 10 occupies along the axis x, a position corresponding to the maximum size of the loop and the sensor 80 is configured and arranged to pass from a closed to open configuration or vice versa when the end 1a 1 occupies, along the axis x, a position corresponding to the lower limit of the loop size. Alternatively, the arrangement of the two parts of the sensor is different. The sensors may each include an actuator disposed outside the space between the two nuts along the x axis and each engaged on a different thread. Alternatively, at least one sensor is of a different type, for example optical or magnetic. Alternatively,

clamping maneuvers or loosening an object by means of the strapping device can be performed in two ways: electrically with sequences of automatic sequences by means of the control device and manually using the knob handle when the control device and / or the motor are not under tension (typically in the case of maintenance). In the case of automatic electric maneuvers, the races are all controlled through sensors (switches). In the case of manual maneuvers the wheel, contactors are of no use to stop the move. We are then faced with the problem of having to limit efforts to stop the race or the screw-nut system. In the case of clamping, when no object enters the strapping, or when it is not fully reached post tightening can take place. It should then stop tightening before the drive is damaged (eg contactors). In the case of release, it is to limit the expansion of the hoop so that it does not come into abutment with the bottom of the slot formed within the frame so that the tightening of the strapping is then still possible. Indeed, the torque limiter acting only in the direction of tightening, the tightening may not be possible with a weaker or motor operator can not print enough torque. The proposed solution allows an expansion and / or a limited tightening of the strapping which prevents damage to the rim and

The controller 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).

Alternatively, the clamping strip 6 does not form a closed loop but an open loop shape. In this case its ends are close during tightening and away when loosening.

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.

The strapping 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 to be clamped. A pad, not shown may be provided next to the area where the band of strands 7 and 8 intersect.

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 respectively fixed in translation along the x axis to the nut 20 and the nut 21 via rods 312 and 313 respectively which intersect. 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. 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, with the 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 rod 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. 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.

CLAIMS

1. A drive device comprising:

- a screw-nut system (17) comprising a threaded rod (18) and a first nut (20; 21) connected to the threaded rod (18) by a helicoidal link,

- a gear (30), for transmitting a rotary movement to the threaded rod (18), a first gearwheel (33) and a second gear (34) meshing with the first gearwheel (33),

- a set of stops (31, 32) comprising a first stop (31) linked to the first wheel (33) rotating about an axis of rotation of the first wheel (33) and a second stop (32) linked to the second toothed wheel (34) rotating about an axis of rotation of the second wheel (34), the first stop (31) and second abutments (32) being configured and arranged to bear one on the other so as to limit an angular travel of the threaded rod (18) at a first angular position in a first direction.

2. A drive device according to the preceding claim, wherein the first stop (31) and the second stop (32) are configured and arranged to bear one on the other so as to limit the angular travel of the threaded rod (18) to a second angular position in a second direction opposite the first direction.

3. Drive device according to claim 1, wherein the set of abutments comprises a third stop (35) linked to the first wheel (33) rotating about the axis of rotation of the first wheel (33) or linked to the second toothed wheel (34) rotating about the axis of rotation of the second wheel (34) and configured and arranged to bear against the second stop (32) or respectively on the first stop ( 31) for limiting the angular travel of the threaded rod (18) to a second angular position in a second direction opposite the first direction.

4. Drive device according to claim 1, wherein the set of abutments comprises a first additional stop (36) linked to the second toothed wheel (34) rotating about the axis of rotation of the second wheel (34 ) and a second additional stop (37) linked to the first wheel (33) rotating about the axis of rotation of the first wheel (33), the additional first abutment and the second additional abutment being configured and arranged to come into bear one against the other so as to limit an angular travel of the threaded rod (18) to a second angular position in the second direction opposite the first direction.

5. Drive device according to any preceding claim, wherein the first toothed wheel (33) has a first number of teeth and the second toothed wheel has a second different number of teeth of the first number of teeth.

6. Drive device according to the preceding claim, wherein the first number of teeth and the second number of teeth are coprime.

7. Drive device according to any preceding claim, wherein at least one abutment of the set of stops capable of occupying a plurality of predetermined fixed angular positions relative to the wheel to which it is linked in rotation about the axis of rotation of the wheel.

8. Drive device according to the preceding claim, wherein at least one stop is removably mounted on the first wheel or the second wheel at an angular position taken from a plurality of angular positions.

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

10. Drive device according to the preceding claim, wherein the threaded rod (18) is coupled to the motor (50) via a torque limiter (54).

January 1. Drive device according to any one of claims 9 to 10, wherein the threaded rod (18) is coupled to the motor (50) via a torque limiter (54) and a freewheel ( 55) configured to allow limiting a torque of the threaded rod (18) along its longitudinal axis in one direction of rotation only.

12. Drive device according to any one of claims 9 to 1 1, comprising a control member (61) and at least one sensor for detecting a first maximum operational angular position of the threaded rod (18) in the first previous direction the first rotational position in the first direction, the controller (61) receiving the measurements from the first position sensor and configured to control the motor (50) from the sensor measures to stop the motor when the first angular position limit is reached.

13. Drive device according to any preceding claim, comprising a knob integral with a toothed wheel of the gear (30) allowing an operator to rotate said gear about an axis of rotation of said sprocket.

14. Strapping device to encircle an object comprising a clamping band including a first end (10) and a second end (1 1) and forming a loop intended to surround the object, the strapping apparatus comprising a device drive according to one of the preceding claims, wherein the drive device 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 in translation along the axis of the threaded rod (18).

15. A strapping machine according to the preceding claim, wherein the first nut is in engagement with a first thread of the threaded shank, the screw-nut system comprising a second nut engaged with a second thread of the threaded rod directed in opposite direction from the first

threading the second end of the clamping band being secured to the second nut in translation along the axis of the threaded rod (18).

16. 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 within the object, the holding device comprising a device drive according to any one of claims 1 to 13, configured for moving the two flanges relative to one another so as to separate them from each other 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 formed in the opposite direction of the first thread, the second flange being integral with the second translation nut according toaxis of the threaded rod (18).