Segment for forming a modular robotic arm

Abstract

The invention relates to a segment (2) for forming a modular robotic arm (1) comprising at least one module (5), wherein the module (5) comprises two half-vertebrae (20) positioned opposite one another and connected by a constant-velocity joint, and an outer shell formed by two hoops (7, 7a, 7b), each having the shape of a truncated trapezoidal cylinder, wherein the hoops (7, 7a, 7b) comprise independent motor-driven pivot connections, and wherein the module (5) comprises a central longitudinal opening intended for the passage of a system for compressing the segment (2) by means of a flexible cable (57) under tension.

Description

Description Title of the invention: Section for forming a modular robotic arm

[0001] The present invention relates to the technical field of sections for forming a modular robotic arm and modular robotic arms comprising such sections.

[0002] In the above field, modular robotic arms are known, consisting of a series of sections. Such robots, sometimes called snake-like, have a possible movement articulated by these sections.

[0003] However, such sections are not interchangeable or removable. And robotic arms made from sections have limited application areas.

[0004] The design of a modular robotic arm also poses the problem of continuity of the mechanical and electronic means and the control means of the modular robotic arm.

[0005] The present invention aims to overcome these drawbacks and proposes a section for forming a modular robotic arm with easily interchangeable sections for a plurality of uses.

[0006] Thus, the invention relates to a section for forming a modular robotic arm comprising at least one module, a module comprising two half-vertebrae positioned opposite each other and linked by a homokinetic joint and an outer casing formed by two ferrules each comprising a trapezoidal cylinder truncated shape, the ferrules comprising motorized and independent pivot connections, the module comprising a central longitudinal opening intended for the passage of a system for compressing the section by means of a flexible cable under tension.

[0007] The implementation of at least one module makes it possible to establish an independent base unit to form a section according to the invention. A module is thus independent and easily connectable to other modules or to a base or even to an effector.

[0008] For the purposes of the invention, two half-vertebrae of a module are connected by a constant velocity joint regardless of the alignment of said half-vertebrae. Such a constant velocity joint ensures equality of rotation speeds of the driving and driven half-vertebrae, while the angle they form is variable and varies. A universal joint is only constant velocity when the proper axes of the two half-vertebrae are aligned.

[0009] For the purposes of the invention, a trapezoidal cylinder truncated is a portion of a cylinder with at least one circular or elliptical section inclined relative to the axis of revolution of the cylinder.

[0010] The outer casing formed by a succession of ferrules including motorized and independent pivot links allows to guarantee all the desired movements of the modular robotic arm. And, the module design comprising two half-vertebrae positioned opposite each other and linked by a constant velocity joint allows to guarantee the relative positioning between the ferrules and a fluid movement when piloting the ferrules by limiting the play between the different parts.

[0011] The implementation of motorized and independent pivot connections between the ferrules can induce play between these parts during their movement and advantageously the constant velocity joint makes it possible to compensate for this play between two successive ferrules of a module.

[0012] Finally, the implementation of sections allows the range of the robotic arm to be freely adjusted according to its desired use.

[0013] Advantageously, a section according to the invention can be simply connected to another section, to a base for a robotic arm and to an effector making it possible to multiply the uses of the modular robotic arm.

[0014] An effector compatible with the modular robotic arm according to the invention can include any type of tool such as a tool holder, a camera, a gripper, a sensor or any type of tooling depending on the desired use.

[0015] According to one embodiment, a section comprises several modules in series. The implementation of modules in series makes it possible to design a section of greater length and facilitates the successive assembly of such sections to form the modular robotic arm.

[0016] According to one embodiment of the invention, the section compression system comprises a flexible tension cable passing through each of the modules. Advantageously, a single flexible tension cable makes it possible to prestress in compression all the modules of the successive sections. According to another embodiment, each section is prestressed independently of each other.

[0017] Advantageously, at the level of the connection between two facing vertebrae, the use of a flexible cable allows the smooth tracking of the neutral fiber of the homokinetic joint.

[0018] According to a characteristic of the invention, a module comprises motor means of at least one shell of the module and means for transmitting the power and control signals of the modular robotic arm.

[0019] Advantageously, each module of a section is capable of transmitting power and control signals from upstream to downstream, for example by means of a connector system. The continuity of the motor means, the electronics and the control means is thus ensured from one section to another.

[0020] According to another characteristic of the invention, a module comprises means for positioning an adjacent module. The implementation of positioning means between two modules facilitates the assembly of a section but also the assembly of two successive sections.

[0021] According to one embodiment of the invention, a half-vertebra comprises a base comprising an upper face provided with a pin extending from the upper face of the base and a cavity located on the upper face of the base and diametrically opposite the pin and capable of receiving a pin from an adjacent half-vertebra. The cooperation of a pin and a cavity of two facing modules makes it possible to simply position two adjacent modules and to guarantee rotational locking of one module relative to the other. Advantageously, the pin is located on the peripheral zone of the upper face of the base in order to increase its lever force.

[0022] According to a characteristic of the invention, a module comprises at least one half-vertebra provided with a base, a first crown positioned around the base capable of collaborating with a ferrule of the module and a second crown extending from the first crown in a longitudinal direction of the module capable of collaborating with a ferrule of the adjacent module.

[0023] Thus, according to this embodiment, a module collaborates with the shell of the module but also with the shell of the adjacent module. Two shells of two adjacent modules thus have a pivot connection with the first crown and the second crown respectively and these connections are motorized and controlled independently.

[0024] According to one embodiment of such a module, the half-vertebra, the first crown and the second crown are monobloc. In the case where they are separate parts, the latter are fixed to each other.

[0025] According to another characteristic of the invention, a module comprises at least one half-vertebra provided with a base and a first crown positioned around the base of the half-vertebra capable of collaborating with a ferrule of the module and a third crown extending from the first crown in a longitudinal direction of the module capable of collaborating with means for fixing the section to an adjacent section or to a base or to an effector.

[0026] Thus, a module located at one end of a section collaborates with the module's ferrule but also with means of fixing the section to an adjacent section or to a base or even to an effector.

[0027] According to one embodiment of such a module, the half-vertebra, the first crown and the third crown are monobloc. In the case where they are separate parts, the latter are fixed to each other.

[0028] According to one embodiment of the invention, the third crown comprises a passage capable of collaborating with a flange intended to hold two sections in succession or to hold a section with a base or an effector.

[0029] Advantageously, the use of a flange makes it possible to maintain a mechanical connection during the assembly phase of the modular robotic arm before the implementation of the section compression system.

[0030] According to a feature of the invention, the passage comprises two opposite rounded edges and two opposite straight edges. A compatible flange comprises a complementary shape making it possible to effectively lock two sections in rotation and to guarantee the positioning of the sections relative to each other.

[0031] According to one embodiment of the invention, a ferrule comprises a main base comprising a first raceway capable of receiving at least in part a first set of balls or rollers and the first crown and the second crown each comprise a first complementary raceway. The implementation of first raceways capable of receiving a first set of balls or rollers makes it possible to ensure a pivot connection between the ferrule and the first crown of a module and between the second crown and the ferrule of an adjacent module.

[0032] According to one embodiment of the invention, a ferrule of a module comprises on its main base an annular re-entrant main edge forming an angle P of between 20° and 50° relative to the plane of the main base of the ferrule and the first crown of the module comprises an annular outgoing main edge forming substantially the same angle p. This embodiment allowing the two ferrules of the same module to be fitted around the second set of balls or rollers ensures an unremovable connection of the ferrules of the module.

[0033] According to one embodiment, two ferrules of a module each comprise a beveled base comprising a second raceway complementary to each other capable of accommodating a second set of balls or rollers. The implementation of second complementary raceways of two ferrules of a module which trap a second set of balls or rollers makes it possible to guarantee a pivot connection between the ferrules of the same module.

[0034] According to a characteristic of the invention, the beveled base is included in a plane forming an angle α of between 10° and 20° relative to the plane of the main base. Numerous tests have demonstrated that an angle of between 10° and 20° makes it possible to reduce the risk of jamming of a ferrule during movement of the modular robotic arm.

[0035] According to one embodiment of the invention, a module comprises a female ferrule and a male ferrule, the female ferrule comprises on its beveled base an annular re-entrant edge forming an angle P of between 20° and 50° relative to the plane of the beveled base of the female ferrule and the male ferrule comprises on its beveled base an annular outgoing edge forming substantially the same angle P, the annular re-entrant edge and the annular outgoing edge each comprising a second raceway. This embodiment making it possible to fit the two ferrules of the same module around the second set of balls or rollers ensures an unremovable connection of the ferrules of the module.

[0036] According to one embodiment of the section according to the invention, two half-vertebrae of a module are connected by a Weiss joint formed by at least four Weiss balls collaborating with the two half-vertebrae, the module comprising means for guiding the flexible cable on the neutral fiber of the Weiss joint. The use of a Weiss joint makes it possible to transmit a rotational movement without play between the two half-vertebrae of a module. According to one embodiment, the flexible cable connects the fragmented line of the centers of rotation of the Weiss joint of each module.

[0037] According to one embodiment, the means for maintaining the Weiss joint comprise a hollow central ball or at least one support point between the two half-vertebrae of the module positioned on the swivel point of the Weiss joint. The longitudinal opening The central part of the module is thus guaranteed by the hollow ball or the space between the two half-vertebrae opposite each other.

[0038] According to a characteristic of the invention, the half-vertebrae comprise a base comprising a central opening and at least two jaws extending from the base, each jaw comprising an internal face having a groove capable of receiving a ball of the Weiss joint capable of translating in the corresponding groove. The use of jaws makes it possible to design the Weiss joint while guaranteeing compactness of the module.

[0039] According to another characteristic of the invention, the groove comprises an angle of inclination y whose value is between 20° and 50°, preferably between 35° and 45°, with the longitudinal direction of the half-vertebra. According to these intervals which are reduced, better mobility has been observed between the two half-vertebrae of a module.

[0040] According to a characteristic of the invention, at least one jaw of a half-vertebra of a module comprises a dedicated housing for motor means of a ferrule of the module. Placing the motor and electronic means at the jaws level makes it possible to guarantee the compactness of the module.

[0041] According to a characteristic of the invention, the base of a half-vertebra comprises at least one window intended for the passage of power and control signals of the modular robotic arm. Advantageously, connectors are located at the level of a window.

[0042] The invention also relates to a modular robotic arm comprising a base, at least one section according to the invention, an effector, and a system for compressing the section(s).

[0043] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive.

[0044] In addition, various other characteristics of the invention emerge from the appended description given with reference to the drawings which illustrate non-limiting embodiments of the invention and where:

[0045] [Fig.l] is a perspective view of an exemplary embodiment of a modular robotic arm according to the invention,

[0046] [Fig.2] is a front view of an exemplary embodiment of a section according to the invention,

[0047] [Fig.3] is a perspective view of an exemplary embodiment of a ferrule called a female ferrule of a module of a section according to the invention,

[0048] [Fig.4] is a sectional view of Figure 3,

[0049] [Fig.5] is a perspective view of an exemplary embodiment of a ferrule called a male ferrule of a module of a section according to the invention,

[0050] [Fig.6] is a perspective view of the section of Figure 2 without its outer casing,

[0051] [Fig.7] is a perspective view of an exemplary embodiment of a half-vertebra of a module of a section according to the invention,

[0052] [Fig.8] is a perspective view of an exemplary embodiment of a male half-vertebra provided with a first and second crown of a module of a section according to the invention,

[0053] [Fig.9] is a perspective view of an exemplary embodiment of a male half-vertebra provided with a first and third crown of a module of a section according to the invention,

[0054] [Fig.10] is a perspective view of an exemplary embodiment of a flange compatible with a third modular crown of a module of a section according to the invention,

[0055] [Fig.11] is a longitudinal half-sectional view of Figure 2, and

[0056] [Fig.12] is a perspective view of an assembly of a modular robotic arm according to the invention.

[0057] It should be noted that in these figures the structural and / or functional elements common to the different variants may have the same references.

[0058] A modular robotic arm according to the invention as illustrated in Figures 1 and designated as a whole by the reference 1 comprises at least one section 2 or several sections 2 placed end to end. Thus, the size of the modular robotic arm 1 is adaptable according to the desired use. For its purposes, the modular robotic arm 1 comprises at one end a base 3 allowing it to be mounted for example on a trolley (not shown), and at the other end an effector 4 chosen according to the desired use of the modular robotic arm 1.

[0059] There are different embodiments of a base 3 and an effector 4 compatible within the scope of the invention.

[0060] According to the embodiment illustrated in Figure 1, the modular robotic arm 1 comprises four sections 2. Each section 2 comprises, according to this example, three modules 5, a flange 6 separating each of the sections 2 while holding them mechanically.

[0061] Figure 2 illustrates a section 2 comprising three modules 5.

[0062] A module 5 according to the invention comprises an outer casing formed by two shells 7. Each shell 7 comprises a trapezoidal cylinder truncated shape, namely a portion of cylinder with at least one circular or elliptical section inclined relative to the axis of revolution of the cylinder.

[0063] A ferrule 7 therefore comprises an annular main base 8 and, opposite, an annular beveled base 9. The two ferrules 7 of a module 5 are linked on their respective beveled base 9 by a pivot connection.

[0064] The beveled base 9 of a ferrule is included in a plane P forming an angle a with the plane Y of the main base 8. According to the embodiment illustrated, the angle a is between 10° and 20°.

[0065] The two ferrules 7 of a module 5 are connected on their respective beveled base 9 by a pivot connection. According to one embodiment, the two ferrules 7 of a module 5 are identical and each comprise complementary pivot connection means on their beveled base 9.

[0066] According to the embodiment illustrated in Figures 3 to 5, a module 5 comprises a female ferrule 7a and a male ferrule 7b allowing the two female ferrules 7a and male ferrules 7b to be fitted together.

[0067] Figures 3 and 4 illustrate a female ferrule 7a comprising an annular main base 8 and an annular beveled base 9. The main base 8 comprises a first circular raceway 10a capable of receiving a first set of balls or rollers (not shown in Figures 3 and 4). The main base 8 comprises a main hole provided with a main obturator 11 opening onto the first raceway 10a and capable of allowing the first set of balls or rollers to pass through.

[0068] According to this particular illustrated embodiment, the beveled base 9 of the female ferrule 7a comprises an annular re-entrant edge 12 forming an angle P with the plane P of the beveled base 9. According to the illustrated embodiment, the angle P is between 40° and 50°.

[0069] The re-entrant edge 12 comprises a second raceway 13a capable of receiving a second set of balls 14 or rollers. The female ferrule 7a also comprises a secondary hole provided with a secondary obturator 15 opening onto the second raceway 13a and capable of allowing the second set of balls 14 or rollers to pass through.

[0070] According to an embodiment not illustrated, the main shutter 11 and the secondary shutter 15 form the same part.

[0071] Figure 5 illustrates a male ferrule 7b comprising an annular main base 8 and an annular beveled base 9. The main base 8 comprises a first circular raceway 10a capable of receiving a first set of balls or rollers (not shown in Figure 5). The main base 8 comprises a main hole provided with a main obturator 11 opening onto the first raceway 10a and capable of allowing the first set of balls or rollers to pass through.

[0072] The beveled base 9 of the male ferrule 7a comprises an annular outgoing edge 16 forming an angle P with the plane P of the beveled base 9 of the male ferrule 7a substantially identical to the angle formed by the inward-facing edge 12 and the beveled base 9 of the female ferrule 7a. According to the illustrated embodiment, the angle P is between 40° and 50° relative to the plane P of the beveled base of the male ferrule 7a.

[0073] The outgoing edge 16 comprises a second complementary raceway 13b capable of accommodating the second set of balls 15 or rollers (not shown in figure 5).

[0074] A module 5 according to the invention also comprises an articulated interior architecture intended in particular to control the motorized and independent pivot connections of the ferrules 7, 7a, 7b.

[0075] To do this, a module 5 comprises two half-vertebrae 20 facing each other linked by a homokinetic joint as illustrated in figure 6.

[0076] Figure 7 illustrates a half vertebra 20.

[0077] The illustrated half-vertebra 20 comprises a base 21 from which two jaws 22 extend. The base 21 comprises a central opening 23 and two windows 24. The base 21 comprises on its upper face a pin 25 located on the periphery and a cavity 26 diametrically opposite the pin 25. The pin 25 and the cavity 26 are located on the area peripheral of the upper face of the base 21. According to other embodiments not illustrated, the half-vertebra 20 comprises three or four jaws 22.

[0078] According to this illustrated embodiment, the two jaws 22 are symmetrical.

[0079] A jaw 22 comprises a surface oriented towards the inside of the half-vertebra 20 and an external surface comprising a housing 27 capable of accommodating motor or control means of a ferrule 7, 7a, 7b.

[0080] The inner surface of the jaw 22 comprises towards its free end a groove 28 intended to receive a ball of a homokinetic joint such as a Weiss joint. According to the illustrated embodiment, the groove 28 forms an angle of inclination of between 20° and 30°, with the longitudinal direction X of the half-vertebra 20.

[0081] Figure 8 illustrates a half-vertebra 20 provided with a first crown 30 and a second crown 31 extending from the first crown 30 in the longitudinal direction X of the half-vertebra 20.

[0082] The first crown 30 is intended to collaborate with the ferrule 7, 7a, 7b of the same module 5 and in particular with the first rolling path 10a arranged in the main base 8 of the ferrule 7, 7a, 7b of the same module 5.

[0083] The first crown 30 surrounds the base 21 of the half-vertebra 20 and comprises a first complementary rolling path 10b intended to accommodate a first set of balls or rollers (not shown in figure 8).

[0084] The second crown 31 is intended to collaborate with the shell 7, 7a, 7b of the adjacent module 5 and in particular with the first raceway 10a arranged in the main base 8 of the shell 7, 7a, 7b of the adjacent module 5.

[0085] The second crown 31 comprises a first complementary raceway 10b intended to accommodate a first set of balls or rollers (not shown in FIG. 8). According to this illustrated embodiment, the second crown 31 is symmetrical to the first crown 30 along a plane orthogonal to the longitudinal direction of the half-vertebra 20. The first crown 30 and the second crown 31 each aim at collaboration with the first raceway 10a of two adjacent ferrules 7, 7a7b.

[0086] According to a non-illustrated embodiment, the main base 8 of a ferrule also comprises means for fitting with a first 30 and / or a second crown 31. For these purposes, a ferrule 7, 7a, 7b of a module 5 comprises on its base main 8 an annular re-entrant main edge forming an angle P of between 20° and 50° relative to the plane of the main base 8 of the ferrule 7, 7a, 7b and the first crown 30 of the module 5 comprises an annular outgoing main edge forming substantially the same angle. And, according to another embodiment not illustrated, the second crown 31 of the adjacent module 5 comprises an annular outgoing main edge forming substantially the same angle p.

[0087] Figure 9 illustrates a half-vertebra 20 provided with a first crown 30 and a third crown 32 extending from the first crown 30 in the longitudinal direction X of the half-vertebra 20.

[0088] The first crown 30 is intended to collaborate with the ferrule 7, 7a, 7b of the same module 5 and in particular with the first rolling path 10a arranged in the main base 8 of the ferrule 7, 7a, 7b of the same module 5.

[0089] The first crown 30 surrounds the base 21 of the half-vertebra 20 and comprises a first complementary rolling path 10b intended to accommodate a first set of balls or rollers (not shown in figure 8).

[0090] The third crown 32 is intended to collaborate with means for fixing the section 2 to an adjacent section 2 or to a base 3 or to an effector 4.

[0091] According to the embodiment illustrated in Figure 9, the third crown 32 is arranged to collaborate with a compatible flange 6.

[0092] The third crown 32 comprises for its purposes a passage 33 formed by two opposite rounded edges 34 and two opposite straight edges 35. According to the illustrated embodiment, the two rounded edges 34 comprise a rim 36.

[0093] Figure 10 illustrates an exemplary embodiment of a flange 6 compatible with two third crowns 32 of two adjacent modules 5 as illustrated in figure 9.

[0094] The particular shape of the flange 6 and of the third crown 32 comprising rectilinear edges 35 illustrated in figures 9 and 10 also allow rotational locking of two half-vertebrae 20 of two successive modules 5.

[0095] To do this, the flange 6 illustrated in Figure 10 comprises two symmetrical parts 40 which are articulated around a pivot axis 41 located at the intersection of two complementary overlapping rectilinear half-edges 42. On the opposite side, two complementary rectilinear half-edges 43 frame two complementary rounded edges 44. The two complementary overlapping rectilinear half-edges 42 and rectilinear half-edges complementary 43 are intended to collaborate with the two opposite rectilinear edges 35 of the third crown 32. Each complementary rounded edge 44 comprises a flange groove 45 intended to collaborate with at least one passage 33 of a third crown 32.

[0096] The opposite complementary rectilinear half-edges 43 each comprise an oblong opening 46 allowing the passage of a clamping screw 56.

[0097] To implement the example of realization of a section 2 illustrated in figures 6 and 11 formed by three modules 5, the three types of crowns 30, 31, 32 are implemented.

[0098] According to the form illustrated in Figure 11, a half-vertebra 20 forms a single-piece assembly with a first 30, second 31 and / or third crown 32. Three types of half-vertebrae 20 are thus implemented. A first module 5 comprises a half-vertebra 20 provided with a first 30 and a third crown 32 linked to another half-vertebra 20, the second module 5 comprises a half-vertebra 20 provided with a first 30 and a second crown 31 linked to a half-vertebra 20 and the third module 5 comprises a half-vertebra 20 linked to a half-vertebra 20 provided with a first 30 and a third crown 32.

[0099] According to the embodiment illustrated in Figures 6 and 11, two half-vertebrae 20 of a module 5 are connected by a Weiss joint. The half-vertebrae 20 of the same module 5 are opposite each other at their respective jaws 22 with an offset of 90° as illustrated in Figure 6. Four jaws 22 are thus assembled so as to trap a Weiss joint. Other types of assembly and constant velocity joint are compatible within the scope of the invention.

[0100] The illustrated Weiss joint comprises four Weiss balls 50 and a hollow ball 51 located centrally at the intersection. Each Weiss ball 50 is housed in a groove 28 of a jaw 22 and is capable of translation in this groove 28.

[0101] Motor means are positioned in the housings 27 provided in the half-vertebrae 20. Electronic means and control means are also located in locations provided in or around the jaws. The windows 24 of each base 21 of the half-vertebrae 20 allow the passage of the connectors.

[0102] Each module 5 illustrated in Figure 11 comprises a female ferrule 7a and a male ferrule 7b. Each female ferrule 7a and male ferrule 7b collaborates with a first 30 or second crown 31 at the level of their respective first complementary rolling path 10b by trapping a first set of balls 52.

[0103] The outgoing edge 16 of the male ferrule 7b is placed against the incoming edge 12 of the female ferrule 7a and the second set of balls 14 or rollers is introduced via the secondary hole of the female ferrule 7a into the second raceways 13a, 13b complementary to each other. The secondary hole is then closed by the secondary shutter 15.

[0104] For the first module 5 formed by a half-vertebra 20 provided with a first 30 and a third crown 32 linked to another half-vertebra 20, the first raceway 10a of the female ferrule 7a is opposite the first complementary raceway 10b of the first crown 30. The first set of balls 52 or rollers is introduced via the main hole of the female ferrule 7a into the first raceways 10a, 10b. The main hole is then closed by the main shutter 11.

[0105] The pin 25 of the base 21 of the half-vertebra 20 of the first module 5 is positioned in the cavity 26 of the base 21 of the half-vertebra 20 of the second module 5 adjacent to the first module 5 and respectively, the pin 25 of the base 21 of the half-vertebra 20 of the second module 5 is housed in the cavity 26 of the base 21 of the half-vertebra 20 of the first module 5.

[0106] And, the first raceway 10a of the male ferrule 7b of the first module 5 is facing the first complementary raceway 10b of the second crown 31 of the second mold 5.

[0107] The first raceway 10a of the female ferrule 7a of the second module 5 is opposite the first complementary raceway 10b of the first crown 30 of the half-vertebra 20 of the second module 5. The first set of balls 52 or rollers is introduced via the main hole of the female ferrule 7a into the first raceways 10a, 10b. The main hole is then closed by the main shutter 11.

[0108] Each module 5 comprises a half-vertebra 20 capable of driving the movement of a ferrule 7, 7a, 7b of the same module 5.

[0109] According to the embodiment of a section 2 illustrated in figure 11, two third crowns 32 are located at each end of the section 2 each comprising means of collaboration with a flange 6.

[0110] According to other embodiments not illustrated, a section 2 comprises other means of attachment to another type of flange not illustrated or may also comprise another attachment system for holding two sections 2.

[0111] To form a modular arm 1 as illustrated in Figure 1, four sections 2 are assembled.

[0112] Figure 12 illustrates the assembly of successive sections 2 secured by means of flanges 6 compatible with the third crown 32.

[0113] The modules 5 of a section 2 comprise means for transmitting the power and control signals of the modular robotic arm 1. These means for transmitting the power and control signals of the modular robotic arm 1 comprise connectors 55 ready for connection and provided at the level of at least one window 24 of a base 21 of a half-vertebra 20 at the ends of a section 2. According to the illustrated embodiment, male connectors 55 of a first section 2 cooperate with female connectors 55 (not visible) of the adjacent section 2.

[0114] The pin 25 of the base 21 of the end half-vertebra 20 of a first section 2 is positioned in the cavity 26 of the base 21 of the end half-vertebra 20 of the adjacent second section 2 and respectively, the pin 25 of the base 21 of the end half-vertebra 20 of the second section 2 is housed in the cavity 26 of the base 21 of the end half-vertebra 20 of the first section 2.

[0115] The flanges 6 are used in particular to hold the sections 2 together during assembly of the modular robotic arm 1. A flange 6 therefore engages with two third rings 32 of two adjacent sections 2 and a clamping screw 56 keeps the flange 6 tight around the two successive sections 2.

[0116] According to the illustrated embodiment, a flexible cable 57 passes longitudinally through each of the sections 2 of the modular robotic arm 1 in their center. Such a system for compressing the sections 2 makes it possible to hold the sections 2 together.

[0117] According to another embodiment not illustrated, each section 2 is prestressed before assembly of the modular robotic arm 1. This embodiment allows simplified assembly of the modular robotic arm.

[0118] The assembled sections 2 are fixed at one end to a base 3 and at the other end to an effector 4 according to the desired use of the modular robotic arm 1.

[0119] Of course, various other modifications may be made to the invention within the scope of the appended claims.

Claims

Claims

1. Section (2) for forming a modular robotic arm (1) comprising at least one module (5), a module (5) comprising two half-vertebrae (20) positioned opposite each other and linked by a homokinetic joint and an outer casing formed by two ferrules (7, 7a, 7b) each comprising a trapezoidal cylinder truncated shape, the ferrules (7, 7a, 7b) comprising motorized and independent pivot connections, the module (5) comprising a central longitudinal opening intended for the passage of a system for compressing the section (2) by means of a flexible cable (57) under tension.

2. Section (2) according to the preceding claim in which a module (5) comprises motor means of at least one ferrule (7, 7a, 7b) of the module (5) and means for transmitting the power and control signals of the modular robotic arm (1).

3. Section (2) according to one of the preceding claims in which a module (5) comprises means for positioning to an adjacent module (5).

4. Section (2) according to the preceding claim in which a half-vertebra (20) comprises a base (21) having an upper face provided with a pin (25) extending from the upper face of the base (21) and a cavity (26) located on the upper face of the base (21) and diametrically opposite the pin (25) and capable of receiving a pin (25) from an adjacent half-vertebra (20).

5. Section (2) according to one of the preceding claims in which a module (5) comprises at least one half-vertebra (20) provided with a base (21), a first crown (30) positioned around the base (21) capable of collaborating with a ferrule (7, 7a, 7b) of the module (5) and a second crown (31) extending from the first crown (30) in a longitudinal direction of the module (5) capable of collaborating with a ferrule (7, 7a, 7b) of the adjacent module (5).

6. Section (2) according to one of the preceding claims in which a module (5) comprises at least one half-vertebra (20) provided with a base (21) and a first crown (30) positioned around the base (21) of the half-vertebra (20) capable of collaborating with a ferrule (7, 7a, 7b) of the module (5) and a third crown (32) extending from the first crown (30) in a longitudinal direction of the module (5) capable of collaborating with means for fixing the section (2) to an adjacent section (2) or to a base (3) or to an effector (4).

7. Section (2) according to the preceding claim in which the third crown (32) comprises a passage (36) capable of collaborating with a flange (6) intended to hold two sections (2) in succession or to hold a section (2) with a base (3) or an effector (4).

8. Section (2) according to the preceding claim in which the passage (36) comprises two opposite rounded edges (34) and two opposite straight edges (35).

9. Section (2) according to one of claims 5 to 8 in which a ferrule (7, 7a, 7b) comprises a main base (8) comprising a first raceway (10a) capable of receiving at least in part a first set of balls (52) or rollers and the first crown (30) and the second crown (31) each comprise a first complementary raceway (10b).

10. Section (2) according to the preceding claim in which a ferrule (7, 7a, 7b) of a module (5) comprises on its main base (8) an annular re-entrant main edge forming an angle P of between 20° and 50° relative to the plane of the main base (8) of the ferrule (7, 7a, 7b) and the first crown (30) of the module (5) comprises an annular outgoing main edge forming substantially the same angle P-

11. Section (2) according to one of the preceding claims in which two ferrules (7, 7a, 7b) of a module (5) comprise a beveled base (9) each comprising a second raceway (13a, 13b) complementary to each other capable of receiving a second set of balls (14) or rollers.

12. Section (2) according to the preceding claim in which the beveled base is included in a plane (P) forming an angle a of between 10° and 20° relative to the plane (Y) of the main base (8).

13. Section (2) according to one of claims 11 or 12 in which a module (5) comprises a female ferrule (7a) and a male ferrule (7b), the female ferrule (7a) comprises on its beveled base (9) an annular re-entrant edge (12) forming an angle P of between 20° and 50° relative to the plane (P) of the beveled base (9) of the female ferrule (7a) and the male ferrule (7b) comprises on its beveled base (9) an annular outgoing edge (16) forming substantially the same angle P, the annular re-entrant edge (12) comprising a second raceway (13a) and the annular outgoing edge (16) comprising a second complementary raceway (13b).

14. Section (2) according to one of the preceding claims in which two half-vertebrae (20) of a module (5) are linked by a Weiss joint formed by at least four Weiss balls (50) collaborating with the two half-vertebrae (20), the module (5) comprising means for holding the flexible cable (57) on the neutral fiber of the Weiss joint.

15. Section (2) according to the preceding claim in which the means for maintaining the Weiss joint comprise a hollow central ball (51) or at least one support point between the two half-vertebrae (20).

16. Section (2) according to one of claims 14 or 15 in which the half-vertebrae (20) comprise a base (21) comprising a central opening and at least two jaws (22) extending from the base (21), each jaw (22) comprising an internal face having a groove (26) capable of receiving a Weiss ball (50) capable of translating in the corresponding groove (26).

17. Section (2) according to the preceding claim in which the groove comprises an angle of inclination y whose value is between 20° and 50°, preferably between 35° and 45°, with the longitudinal direction of the half-vertebra.

18. Section (2) according to one of claims 16 or 17 in which at least one jaw of a half-vertebra (20) of a module (5) comprises a dedicated housing for motor means of a ferrule (7, 7a, 7b) of the module (5).

19. Section (2) according to one of claims 4 to 18 in which the base of a half-vertebra (20) comprises at least one window (24) intended for the passage of power and control signals of the modular robotic arm (1).

20. Modular robotic arm (1) comprising a base (3), at least one section (2) according to one of the preceding claims, an effector (4), and a system for compressing the section(s) (2).

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