EP2943317A1

EP2943317A1 - Pure translational serial manipulator robot having three degrees of freedom with a reduced space requirement

Info

Publication number: EP2943317A1
Application number: EP14700568.0A
Authority: EP
Inventors: Farès KFOURY
Original assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2013-01-08
Filing date: 2014-01-08
Publication date: 2015-11-18
Also published as: FR3000696B1; US20150336266A1; WO2014108424A1; JP2016505396A; FR3000696A1

Abstract

A serial carrier having at least three degrees of freedom, comprising three pivot links, two of which have orthogonal axes (X1, X2), one of the first, second and third links being used to couple the carrier to a frame, and comprising an effector (8), said carrier comprising two passive deformable-parallelogram devices (4, 6) in the plane linked to the frame and to the effector (8), and first and second passive transmission devices (D1, D2) each formed by a double universal joint, the first double universal joint (D1) being linked to the frame and the second double universal joint being linked to the effector, the two double universal joints being linked together, said deformable-parallelogram devices (4, 6) and said transmission devices (D1, D2) being capable of restricting the movement of the effector (8) to only three degrees of freedom of translation.

Description

PURE TRANSLATIONAL MANIPULATOR ROBE WITH THREE DEGREES OF FREEDOM SERIES A

SMALL FOOTPRINT

DESCRIPTION TECHNICAL FIELD AND PRIOR ART

The present invention relates to a robot manipulator or carrier with three degrees of freedom reduced space.

Manipulator robots are widely used in the industry to perform tasks that may be repetitive, painful, or require a high level of repeatability. One of the most common tasks of a robot is to position and / or orient any solid in space. For this task, several criteria can contribute in the definition of the architecture of the manipulator such as the reachable space, the footprint, the load capacity ...

The structure of a manipulator robot is generally formed of two parts. A first part comprising first axes starting from the frame, used to position the load manipulated and which constitutes what is called the "carrier", and a second part bearing the last axes, used to guide the load and which constitutes " wrist".

There are two types of carriers, carriers with parallel architectures and carriers with series architectures.

The carriers with parallel architectures comprise a frame, several identical branches connected to the frame, the branches being composed of series robots whose links are prismatic, rotoid, ..., motorized or not, and a platform constituting the effector of the robot, to which are connected the endings of all the branches. These carriers have a significant footprint compared to the work space achievable.

The series architecture carriers are formed of mechanical links in series. In addition, in order to position any object in space, they are provided with at least three links to cover the three degrees of freedom of translation. It could be in order, three rotoid links, three prismatic links, two rotoid links and one prismatic link or one rotoid link and two prismatic links.

These have the advantage of offering the widest possible area to reach given ground.

When a carrier has rotoidal connections, each of them induces a rotation on the load during the positioning thereof, ie each displacement of the load by a rotoid connection is composed of a translational movement and a rotation movement. However, in some cases, it is preferable for the wearer to move the load only in translation, in order, for example, to decouple the positioning and the orientation, that is to say the axes of the wearer and those of the wrist.

Carriers in which induced rotations are suppressed are developed.

For example, the company KUKA realizes a series carrier with three degrees of freedom having an architecture with three rotoid links. This carrier is for example described in the document Innovation in the Flexibility of Food Packaging Machinery, Dena Mullen, 2/10/06, Clemson Univeristy. In order to suppress the rotations induced by the rotoid links, an additional device consisting of the recovery bars and a square has been added. This device, passive and space-saving, has the function of keeping the effector of the robot horizontal. Thus the rotations induced by the rotoidal links of horizontal axes are suppressed. To compensate for the rotation induced by the vertical axis rotational connection, additional means formed by a motorized vertical axis of rotation have been added at the effector. Therefore this robot is relatively complex by its implementation, and by its operation because of the additional motorized means.

In addition, the additional motorized means at the effector form a load embedded on the robot, attributable to the total load capacity of the latter. STATEMENT OF THE INVENTION

It is therefore an object of the present invention to provide a serial carrier with at least three degrees of freedom, in which the orientation of the effector is made relatively independent of its positioning in a relatively simple manner, ie without additional motorization and space-saving, ie whose impact on the reachable space is substantially reduced.

The previously stated purpose is achieved by a serial carrier having at least three degrees of freedom including a frame, members hinged together, a member hinged to the frame and an effector carried by one of the members, and at least three connections between the members and the frame, at least two of the three links being orthogonal axis rotational links and the other being a rotoid connection or a prismatic connection, said carrier comprising at least a first deformable parallelogram device and a passive device transmission of the orientation of the frame of the carrier to the effector of the carrier, said passive transmission device having two links each having at least two intersecting axes of rotation.

In other words, there is provided a carrier comprising at least one deformable parallelogram device and an orientation transmission device, forming passive means securing the orientation of the effector to that of the base of the wearer.

The passive means can be used in other ways, for example to deport at the base of the robot the actuation of one or other of the rotations at the wrist, offering the advantage of obtaining an actuation of these rotations decoupled from the axes of the wrist. carrier for positioning the load.

Particularly advantageously, the passive orientation transmission device is formed by a double universal joint. It is very simple structure and very robust.

Also particularly advantageously, the carrier has three rotoid links. It offers a very attainable space in relation to its footprint. In a preferred embodiment, the third link is a rotoid link with an axis parallel to one of the first two links, the two parallel axis rotational links being consecutive, and the robot comprises two planar deformable parallelogram devices and two passive transmission devices.

The passive transmission devices according to the invention also offer the advantage of being adaptable to different carrier architectures. Their addition does not increase the degree of hyperstatism of the original wearer. In addition, they are not motorized, they do not cause complexification of the control systems and the carrier power supply.

In addition, they are not bulky, and follow the morphology of the wearer so as to have the lowest possible impact on the initial reachable space of the wearer.

The present invention therefore relates to a serial carrier with at least three degrees of freedom, comprising a first and a second rotoidal connection of orthogonal axes and at least a third rotoid or prismatic connection, one of the first, second and third links for articulating the carrier on a frame, and comprising an effector, said carrier comprising at least one passive device with deformable parallelogram in the plane connected on the one hand to the frame and on the other hand to the effector, and at least a passive transmission device, said transmission device, comprising a first, a second and a third element, the first element being connected to the frame and having a fixed orientation with respect thereto, the third element being connected to the effector and having a fixed orientation with respect to it, and the second element being articulated to the first element and the third element by two links each carrying at least two secant rotation axes, said at least one deformable parallelogram device and said at least one transmission device being able to restrict the movement of the effector to only three degrees of freedom of translation.

In an exemplary embodiment, the passive device with deformable parallelogram is an angle device comprising a parallel arm and a recovery bar and connected by two connecting rods by pivot links, one of the rods having the shape of a square on which is articulated the second element. In another exemplary embodiment, the passive deformable parallelogram device is a cable loop device.

In one embodiment, the transmission device may be of fixed length and form a deformable parallelogram in space with an arm of the passive device with deformable parallelogram. At least one of the links, which comprises at least one transmission device, can then connect the second element to the first element and the third element is a ball joint.

In another embodiment, the transmission device is a double universal joint. Advantageously, the double universal joint has a variable length.

The third link may be a rotoid link with an axis parallel to that of one of the other two links, comprising a second device with a deformable parallelogram in the plane, arranged between the first deformable parallelogram device and the effector.

The second deformable parallelogram device in the plane may be a square system whose bracket is common to the first bracket device, the second bracket device connecting the first bracket device to the effector, the first and second brackets being articulated on the bracket, said carrier also having a second transmission device connecting the first transmission device to the effector, the two transmission devices being connected by an articulated member by a pivot connection relative to said bracket.

The second transmission device is for example a double universal joint.

The third link may be a prismatic link, the planar deformable parallelogram device being a cable and muffle device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood with the help of the following description and figures in which: FIG. 1 is a perspective view of an exemplary embodiment of a carrier with three rotoid links according to the invention,

FIG. 2 is a schematic representation of a double universal joint,

FIG. 3 is a side view of a variant of the carrier of FIG.

1 exhibiting degree 2 hyperstatism,

FIGS. 3A and 3B are partial views of the carrier of FIG. 3 on which a deformable parallelogram in the space formed by the transmission device D1 and segment 10 is represented,

FIG. 4 is a view from above of a carrier of FIG. 3 in two extreme positions,

FIGS. 5A and 5B are partial perspective views of a carrier according to another exemplary embodiment implementing ball joints in two different positions (FIG. 5B shows in particular the effect generated by the replacement of the cardan joints; by patella),

FIG. 6 is a perspective view of another embodiment of a carrier with three rotoid links,

FIG. 7 is a perspective view of another embodiment of a carrier with three rotoid links according to the invention,

FIG. 8 is a perspective view of an exemplary embodiment of a carrier with two consecutive rotoid links and a prismatic connection according to the invention,

FIG. 9 is a perspective view of an exemplary embodiment of a carrier with two non-consecutive rotoidal connections and a prismatic connection according to the invention;

FIG. 10 is a perspective view of an example of a flat deformable parallelogram device formed by a cable loop,

FIGS. 11A to 11D are detailed perspective views of the structure of the carrier of FIG. 1. DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

The present invention relates to a carrier having at least three links, of which at least two are orthogonal axis rotational links XI and X2 and the third is a rotational link X4 axis or a prismatic link Yl axis. The axes XI, X2 and X4 will be used throughout the description to designate the axes of the rotoidal connections of the wearer, the axis XI being orthogonal to the environment to which the wearer is attached, for example the floor or a wall, and the axes X2 and X4 are orthogonal to the axis XI. The same references are used in the description of the various examples and embodiments to designate elements having the same functions.

The terms "horizontal" and "vertical" are considered in relation to the representation of the figures in the drawings and are in no way limiting. Indeed, a carrier whose frame is fixed on an inclined ground and whose axes of rotoidal connections are neither vertical nor horizontal, is not beyond the scope of the present invention. In addition, the carrier can be inclined relative to the ground or the wall to which it is attached.

In Figure 1, we can see an example of a particularly advantageous embodiment of a PI series carrier with three rotoid links comprising a frame 2, intended to be fixed. In the example shown it is fixed to the ground. The carrier has several elements articulated between them and articulated on the frame 2.

The carrier PI comprises a yoke 3 rotatably mounted on the frame 2 about the vertical axis XI forming the first rotoid connection, a first articulated assembly 4 deformable parallelogram, mounted articulated in rotation on the yoke 3 about the axis horizontal X2 with a first longitudinal end 4.1 forming the second rotoid connection, a second articulated assembly 6 with a deformable parallevelogram mounted articulated in rotation about the axis X4 by a first longitudinal end 6.1 on a second longitudinal end 4.2 of the first hinged assembly forming the second rotoid link, and an effector 8. The axis X4 is parallel to the axis X2 in this embodiment.

The effector 8 is for example a device capable of carrying a load or a tool. Articulated assemblies 4 and 6 have a deformable parallelogram structure which is well known to those skilled in the art, these will be briefly described.

The articulated assembly 4 comprises a support arm 10 and a recovery arm 12 mounted parallel to each other.

The carrying arm 10 is articulated on the yoke 3 about the axis X2, and a rod 14 is articulated on the support arm 10 about the axis X2 and is articulated in rotation about an axis X2 'parallel to X2 on the lever arm 12. The rod 14 has a fixed orientation relative to the yoke 3, which imposes the orientation of the bracket 16 around X4. Alternatively, one can consider actuating the rod 14 around X2, which allows to deport to the base of the robot actuation of one or other of the rotations at the wrist, offering the advantage of to obtain an actuation of these rotations decoupled from the axes of the carrier used to position the load.

The carrying arm 10 is articulated at its other longitudinal end about the axis X4 on a bracket 16 and the recovery arm 12 is also articulated on the bracket 16 about an axis X4 'parallel to the axis X4.

The support arm assembly 10, recovery arm 12, rod 14 and bracket 16 forms a planar deformable parallelogram, contained in a substantially vertical plane.

The second articulated assembly 6 comprises an arrow arm 18 and a recovery arm 20 parallel to each other and articulated by a first end on the bracket 16 respectively about the axis X4 and an axis X4 "parallel to the axis X4, and by a second end to a platelet link 22 respectively about the axis X5 and an axis X5 'parallel to the axis X5. The bracket 16 is common to the two articulated assemblies 4, 6.

The effector 8 is pivotally connected about an axis parallel to the axis XI with the plate 22.

The articulated assemblies move the plate 22 and the effector 8 into space while maintaining it in horizontal orientation. The plate 22 and the effector 8 thus keep a horizontal orientation whatever their movements in the different directions of space.

The one or more deformable parallelogram articulated assemblies could be replaced by one or more parallelogram cable devices as shown in FIG. 10 in two positions. We consider for example the case where the cable parallelogram device replaces the articulated assembly 4, the pulley PI represents the rod 14: its center is carried by the axis X2, and it is fixed relative to the yoke 3. The P2 pulley is embedded in the square 16. Its center is carried by the axis X4 and it is in the same plane as the pulley Pl. Finally, a loop of cable C is wrapped around the two pulleys, and a point of the cable Cl is crimped on the pulley PI, and a second point P2 of the cable is crimped on the pulley P2. Thus, the orientations of the two pulleys PI, P2 around the axes X2 and X4 are coupled. Alternatively, the hen P21 can replace the bracket 16, in this case the assembly 6 is also formed by a parallelogram cable. For this purpose, the pulley 16 is a double groove pulley to form one of the pulleys of the cable parallelogram replacing the deformable parallelogram 6.

The carrier also comprises first and second devices D1 and D2 for transmitting the orientation of the frame 2 to the effector 8.

The first D1 and second D2 devices for transmitting the orientation of the frame to the effector are formed by double cardan joints. For the sake of simplicity, the devices D1 and D2 will be designated hereafter as a transmission device D1 and a transmission device D2.

A double universal joint is shown diagrammatically in FIG. 2, which comprises a central member 24 of longitudinal axis provided at its two ends with a fork 26, 28 and two other forks 30, 32 connected respectively to the forks 26, 28 by a cross 34, 36 carrying four axes perpendicular to each other.

In general, the forks 26, 28 are carried at the end of an input shaft and at the end of an output shaft. The double universal joint makes it possible to obtain rotation transmission between any input shaft and any output shaft. If the forks 26 and 28 are coplanar, and the output axis is parallel to the input shaft, the universal joint is then called 'homokinetic', and the rotational speeds of the input and output shafts are rigorously equal.

In the example shown, a rod 40 is fixed on the frame, the first end 38 of the transmission device D1 is connected to the rod 40 and has a fixed orientation relative thereto.

The link The transmission device D1 comprises a second end 42 linked to, and has a fixed orientation relative to a bar 44 which is articulated in rotation on the bracket 16 about an axis X3 parallel to the axis XI. The bar 44 is rotatably mounted on a rod 47 integral with the bracket 16.

The transmission device D2 has a first end 46 connected to the bar 44 and has a fixed orientation relative thereto. The transmission device D2 has a second end 48 connected to the effector 8 and has a fixed orientation relative thereto. In the example shown, a rod 50 is fixed on the effector 8, the second end of the transmission device D2 is embedded on the rod 50.

The connections between the second end 42 of the transmission device D1 and the bar 44, between the first end 46 of the transmission device D2 and the bar 44, between the second end 48 of the transmission device D2 and the effector 8 are either slides, or recesses, all the links are not necessarily the same type.

The rod 50 passes through the plate 22 and is in axis X7 pivot connection parallel to the axis XI with the plate, so that the effector is in pivot connection with the plate. The plate can be pierced to accommodate a bearing, which will provide the pivot connection between the effector and the plate.

In the example shown and particularly advantageously, the transmission devices comprise a slide connection 52, 54 at their central member so that the central member is of variable length. The transmission devices D1 and D2 transmit the vertical axis orientation to the effector via the bar 44 and the rod 50. This embodiment with variable length transmission devices makes it possible to obtain a global isostatic assembly. Therefore, it offers the advantage of having a great freedom in the realization of the carrier, more particularly in the arrangement of the axes.

Indeed, the carrier may be such that the axes XI and X2 are not concurrent as shown in Figure 11A.

The articulated assemblies can also be made so that the recovery arms define a plane T that does not contain the axis XI, as shown in FIG. 11B.

The axis of the pivot connection between the bar 44 and the rod 47 secured to the bracket may not be intersecting with the axis X4, as shown in Figure 11C.

In addition, the axis of the pivot connection between the plate 22 and the effector 8 may have any position relative to the plate 22, as shown in Figure 11D.

The fixed position of the rod 40 with respect to the ground can be arbitrary.

In an alternative embodiment P2 of the carrier of Figure 1 shown in Figures 3 and 4, which offers the advantage of a simplified embodiment, the transmission devices are of fixed length. In this embodiment, the carrier is such that the axes XI and X2 are concurrent, the articulated assemblies are such that the recovery arms 12, 20 define a plane containing the axis XI. The axis of the pivot connection between the bar 44 and the rod 47 secured to the bracket is secant with the axis X4 of the rotoid connection. In addition, the axis of the pivot connection between the plate 22 and the effector 8 is in the plane defined by the recovery arms which contains the axis XI and more is secant with the axis of rotation between the arm of arrow 18 and the plate 22 and the rod 40 has a length and a ground position such that the support arm 10 and the central element of the device D1 form a parallelogram.

The transmission devices D1 and D2 then form, with the segments 10 and 18 of the carrier, deformable parallelograms in space. The parallelogram is deformed by rotation around one of its sides, and / or by modification of its angles. The deformable parallelograms are shown in dashed lines in FIGS. 3A and 3B.

It is possible to envisage a carrier which would differ from that of FIGS. 3 and 4 in that the axis of the pivot connection between the plate 22 and the effector 8 would have any position relative to the plate 22. In this case, only one transmission devices, the second could include a slide link.

We can also consider a carrier that differs from that of Figures 3 and 4 in that the fixed position of the rod 40 would be any relative to the ground.

In this case also, only one of the transmission devices, the first, could include a slide connection.

FIGS. 5A and 5B partially show a carrier showing the structure of the carrier of FIGS. 3 and 4, but including transmission devices D1 D2 'in which at least one of the universal joint spacers is replaced by a ball joint. This carrier nevertheless has singular positions, and its achievable space is considerably limited compared to the carrier having dual cardan joints. In the present invention, in the case where the handling and the displacement of the load are provided by the wearer and the suppression of a vertical axis induced rotation is provided by the devices D1, D2, the transmission devices D1 and D2 do not see the load and can have relatively small dimensions compared to other segments of the carrier.

It will be understood that the shape of the elements 40, 44 and 50 is not limiting and any other form may be suitable.

Thanks to the invention, the horizontal orientation of the effector is maintained regardless of its displacement in space by the control of the first and second articulated assemblies and thanks to the planar deformable parallelogram devices, and the orientation of vertical axis is maintained through transmission devices Dl and D2.

In Figure 6, we can see another embodiment of carrier P3 three roto links. The carrier has two rotoidal links of parallel axes X2 and X4 and a rotoid link of axis X1 orthogonal to X2 and X4. The two rotational links of axes X2 and X4 generate induced rotations of axes parallel to the axis X2 (and to the axis X4) and the rotoid connection of axis XI generates an induced rotation about the axis XI.

In this example, the carrier is attached to a vertical wall M, for example a wall. The carrier comprises a frame recessed wall M, two articulated assemblies 4, 6, a first articulated assembly 4 on the frame 2 about the axis X2 and a second articulated assembly 6 on the first element articulated about the axis X4. The first 4 and second 6 articulated assemblies make it possible to eliminate the induced rotations of axes parallel to the axis X2.

The carrier comprises a third deformable parallelogram assembly 57 hinged to the second articulated assembly 6 about the axis XI, and a transmission device D1 for transmitting the orientation of the wall to the effector. The axis XI is carried by the second segment of the robot, it remains horizontal but not necessarily perpendicular to the wall.

For this, a plate 55 is articulated about an axis X5 parallel to X4, the second end of the second articulated assembly 6 and on which a rod 56 is fixed. The plate 55 has a fixed orientation with respect to the frame 2 fixed to the wall thanks to the two articulated assemblies 4 and 6. The transmission device D1 connects the rod 56 to the effector 8 which is in pivot connection axis parallel to X4 with the plate 22 of the third articulated assembly 57. The transmission device makes it possible to cross the rotoid connection of axis XI, the induced rotation of axis XI is suppressed by the articulated assembly 57. The effector maintains a fixed orientation relative to the plate 55 and therefore relative to the frame 2 through the transmission device Dl.

As mentioned for the previous example, the transmission device comprises a slide connection so as to have a variable length thus making the assembly isostatic. However, it is possible by means of a particular arrangement of the joints of the device D1, to form a deformable parallelogram in the space between the latter and the articulated assembly 57. In this case the slide connection of the device D1 can be omitted. with a functional hyperstatic assembly. As mentioned for the previous example, at least one of the universal joints of the device D1 can be replaced by a ball joint. The reachable space of the robot is considerably reduced because of a singular position introduced by the ball joint.

In FIG. 7, another example of carrier P4 with three orthogonal axis roto-links can be seen.

This carrier differs from that of FIG. 1 in that the axes of three rotoid links are orthogonal. The carrier comprises two articulated assemblies 4, 6, the second articulated assembly 6 being articulated on the first articulated assembly 4 around the axis X4.

The carrier implements a transmission device D1 linking the rod 40 to the bar 44, a second transmission device D2 linking the bar 44 to the effector 8, these two transmission devices D1, D2 ensuring the transmission of the orientation vertical axis; and a third transmission device D3 between the bracket 16 and a plate 22 articulated in rotation around an axis parallel to the axis X2 on the connecting rod 23 of the second articulated assembly. The effector 8 is articulated on the plate 22 about an axis parallel to the axis XI. This third transmission device D3 ensures the transmission of the horizontal axis orientation parallel to X2 to the plate 22, which is imposed on the effector.

In Figure 8, we can see another embodiment of carrier P5 with two consecutive rotoid links of orthogonal axes and a prismatic connection.

The rotoid links have axes designated XI and X2 and the prismatic link has an axis designated Y1.

The carrier P5 comprises a frame 2 on which is mounted a yoke 3 articulated in rotation around the axis XI, a support arm 62 rotatably articulated in the yoke 3 about the axis X2 and a carriage 64 able to slide on the carrier arm 62 along the axis Y1.

A plate 66 is articulated in rotation about an axis parallel to X2 on the carriage 64 and the effector 8 is articulated in rotation on the plate.

A cable and muffle system 67 known to those skilled in the art connects the axis X2 to the plate 66 so that the plate 66 remains horizontal in the example represent. The cable and mitt system is shown partially in Figure 8 for clarity.

The cable and muffle system is well known to those skilled in the art and its operation will be described briefly. This is used to suppress a rotation whose axis is perpendicular to the axis of a slide link to cross.

When the carriage 64 is translated relative to the support arm 62, the two mittens 68 move in the same direction and of the same value along the axis Y1, and keep the cable 70 taut. When the assembly rotates about the axis X2, the mittens 68 remain motionless relative to the carrying arm 62, and the cable 70, fixed on a pulley 72 connected to the plate 66 on the one hand and on the pulley 71 connected to the clevis 3 on the other hand, makes it possible to eliminate the rotation induced on the plate 66.

A transmission device D1 with double universal joints is provided between the frame 2 and the effector 8 so as to maintain the axis orientation parallel to the axis XI of the effector 8 relative to the frame 2. The device transmission also has a slide connection making the carrier isostatic.

According to another embodiment not shown, it is possible to produce a carrier comprising in order, from the frame, a prismatic connection, and two rotoidal links of orthogonal axes, in which the orientation of the effector is connected to that of the building. For example, it is possible to make such a carrier starting from the architecture of the carrier of FIG. 6, and modifying it so as to replace the X2 axis pivot connection linking the robot to the frame by a slide connection of axis X2. . The return bar of the articulated assembly 4 can be omitted, and the bracket 16 can then be embedded in the support arm 10.

FIG. 9 shows another example of a carrier P6 having two orthogonal axis rotational connections and a prismatic connection, in which the two rotoid links are not consecutive.

The carrier comprises a frame 2 fixed to the ground, a shaft 74 rotatable relative to the frame about an axis XI, a carrier arm 75 fixed to the shaft 74 along which is slidable a carriage 77 along Yl axis, an articulated parallelogram assembly 4 mounted hinged on the carriage 77 about the axis X2. A cable and muffle system 67 to cross the slide connection makes it possible to eliminate the rotation induced by the rotoid link with axis XI, and to thus link the orientation of the plate 78 to that of the frame, the plate 78 being in pivot connection of axis parallel to XI with the carriage 77. The articulated assembly 2 makes it possible to eliminate the induced rotation of the rotoid link with axis X2 and thus to maintain the orientation of the plate 22 horizontally, the latter being in pivot connection of axis parallel to X2 relative to the support arm 10 of the articulated assembly 4

A dual cardan joint transmission device Dl connects the orientation of the effector 8 to that of the plate 78, the latter being, as in the example of FIG. 1, in pivot connection with an axis parallel to XI with the plate. 22.

The orientation of the effector is thus linked to that of the frame.

In the example shown, the transmission device also comprises a slide connection making the assembly isostatic.

In all the examples described, the double cardan joint transmission devices may comprise a slide connection so as to have a variable length and allow isostatic structures to be produced.

In all the examples described, the universal joint connections of the transmission devices, whose length is fixed, can be replaced by ball joints, with a particular arrangement of the joints of these devices, so that they form with the corresponding articulated sets, deformable parallelograms in space.

In the example shown, the transmission of the fixed orientation of the frame to the effector has been described. It keeps a constant orientation regardless of its movements in space. It may be envisaged to modify this orientation by providing a device linked to one of the double universal joints and to the frame or to an intermediate element having the orientation of the frame, able to move the double universal joint and to act on it. orientation of the effector. Thus, the control of the orientation of the effector is offset on the frame or at the intermediate element and is not shipped at the effector. Taking the example of the carriers P2, P4 and P5 (FIGS 3, 7, and 8), the actuation of the vertical axis rotation is done by actuating the rod 40 in rotation around the axis XI relative to on the frame, for example on a turntable. On the carrier P3 of Figure 6, it is possible to actuate the rod of the articulated assembly 4 in rotation about the axis X2. Concerning the carrier P6 of FIG. 9, the orientation holding cable may be replaced by a toothed belt, which will allow the vertical axis to be actuated by the plate 78 and the effector 8.

Thanks to the invention, the series carriers form pure translational positioners.

The means implemented by the invention have the advantage of being passive, in embodiments, they do not involve motorized means and in other embodiments, the motorized means are upstream of the devices of the invention. transmission, nor to be ordered, they do not increase the degree of hyperstatism of the original bearer. They perform the function of suppressing induced rotations, which is separate from the function of handling the load provided by the wearer himself.

Depending on the configuration, they can be solicited by relatively small efforts, and their dimensions can then be reduced compared to the initial carrier.

In addition, these means are easily integrable to existing carriers, they are relatively discrete and compact and follow the morphology of the wearer so that they have a very low impact on the achievable space of the original wearer.

Claims

Serial carrier with at least three degrees of freedom, comprising a first and a second rotoidal connection of orthogonal axes (XI, X2) and at least a third rotoid or prismatic connection, one of the first, second and third links for articulating the carrier on a frame, and comprising an effector (8), said carrier comprising at least one passive device with deformable parallelogram (4, 6) in the plane connected on the one hand to the frame and on the other hand to the effector (8), and at least one passive transmission device (D1, D2, D3), said transmission device, comprising a first, a second and a third elements, the first element being connected to the frame and having an orientation fixed relative to the latter, the third element being connected to the effector (8) and having a fixed orientation with respect thereto, and the second element being articulated to the first element and the third element by two composite links. each being at least two intersecting axes of rotation, said at least one deformable parallelogram device (4, 6) and said at least one transmission device (D1, D2, D3) being able to restrict the movement of the effector (8 ) only three degrees of freedom of translation.

Serial carrier according to claim 1, in which the passive device with a deformable parallelogram (4, 6) is an angle device comprising an arm

(10, 18) and a recovery bar (12, 20) parallel and connected by two connecting rods by pivot connections, one of the rods having the shape of a bracket (16) on which is articulated the second element.

Serial carrier according to claim 1, wherein the passive device with deformable parallelogram is a cable loop device.

A serial carrier according to claim 1, 2 or 3, wherein said transmission device is of fixed length and forms a deformable parallelogram in space with an arm of the passive device with deformable parallelogram and in which at least one of the connections, that said at least one device for transmission, connecting the second element to the first element and the third element is a ball joint.

Serial carrier according to claim 1, 2 or 3, wherein the transmission device (D1, D2, D3) is a double universal joint.

6. A series carrier according to claim 5, wherein the double universal joint (D1, D2, D3) has a variable length.

7. Serial carrier according to one of claims 1 to 6, wherein the third link is a rotational axis link (X4) parallel to that (X2) of one of the other two links, comprising a second parallelogram device deformable (6) in the plane, arranged between the first deformable parallelogram device (4) and the effector (8).

8. A serial carrier according to claim 7 in combination with claim 2, wherein the second deformable parallelogram device (6) in the plane is a bracket system whose bracket (16) is common to the first bracket device (4). ), the second angle device (6) connecting the first angle device (4) to the effector (8), the first and second angle devices (4, 6) being articulated on the bracket (16), said carrier also comprising a second transmission device (D2) connecting the first transmission device (D1) to the effector (8), the two transmission devices (D1, D2) being connected by a member (44) articulated by a pivot link relative to said bracket (16).

The carrier of claim 8, wherein the second transmission device (D2) is a double universal joint.

The carrier of claim 1, wherein the third link is a prismatic axis link (Y1) and wherein the planar deformable parallelogram device is a cable and muffle device.