Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J9/00—Programme-controlled manipulators
  • B25J9/10—Programme-controlled manipulators characterised by positioning means for manipulator elements
  • B25J9/104—Programme-controlled manipulators characterised by positioning means for manipulator elements with cables, chains or ribbons
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H19/00—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion
  • F16H19/02—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion
  • F16H19/06—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion comprising flexible members, e.g. an endless flexible member
  • F16H19/0622—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion comprising flexible members, e.g. an endless flexible member for converting reciprocating movement into oscillating movement and vice versa, the reciprocating movement is perpendicular to the axis of oscillation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
  • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
  • F16H25/20—Screw mechanisms
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H19/00—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion
  • F16H19/02—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion
  • F16H19/06—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion comprising flexible members, e.g. an endless flexible member
  • F16H2019/0695—Generating pivoting movement of a joint
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
  • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
  • F16H25/20—Screw mechanisms
  • F16H2025/204—Axial sliding means, i.e. for rotary support and axial guiding of nut or screw shaft
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
  • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
  • F16H25/20—Screw mechanisms
  • F16H2025/2062—Arrangements for driving the actuator
  • F16H2025/2075—Coaxial drive motors

Definitions

• the invention relates to a cable jack for increased angular deflection.
• Cable jacks comprising a screw / nut assembly whose screw is rotated by an electric motor, and whose nut is movable in translation.
• the movable element is coupled to one or more cables to exert traction on them.
• Document FR2809464 discloses such a cable jack, in which the element in translation is the screw, while the nut is rotatable under the action of a motor.
• the cable passes through a hole in the screw and is coupled by means of a fastener that is tolerant of misalignment of the cable.
• Such a cable jack can be used to actuate a robot arm segment, or a phalanx of a finger.
• the movable element is integral with a rotating shaft which comprises a pulley on which the cable is wound.
• a rotating shaft which comprises a pulley on which the cable is wound.
• the size of the cylinder is very critical, and it is important to ensure that this size is as small as possible. It is known in this respect of cable cylinders comprising a screw mounted to rotate and driven by an electric motor, a nut cooperating with the screw and associated with anti-rotation means so that a rotation of the screw under the action of the motor causes axial displacement of the nut, and two substantially parallel cables coupled to the nut on the other side thereof.
• This device allows, for the same stroke, to reduce the size of the cable jack.
• the overall size would be at least 2C + L, where C is the stroke of the cylinder, and L the size of the nut. In the displaceable nut cylinder, this minimum space requirement is only C + L.
• the invention aims to provide a cable jack of the aforementioned type, allowing increased travel of the associated joint.
• a cable actuator comprising a screw rotatably mounted and driven by an electric motor, a nut cooperating with the screw and connected to means anti ⁇ rotation so a rotation of the screw under the action of the motor causes an axial displacement of the nut, and two cables coupled to the nut on the other side thereof to extend symmetrically with respect to an axis of rotation of the screw, the two cables being wound on respective pulleys both integral with the same rotating shaft and in which the pulleys are of the helical groove type, the helical grooves of the pulleys extending in opposite directions.
• the use of a two-wire jack associated with two helical grooved pulleys mounted in opposite directions keeps the winding radius constant, while canceling by symmetry the lateral forces generated by the non-parallel arrangement of the cables.
• FIG. 1 is a partial perspective view of a cable jack according to a particular embodiment of the invention.
• FIG. 2 is a perspective view of the cylinder of Figure 1 showing the rotating shaft of the joint;
• FIGS. 3A and 3B are top views of the cylinder of Figures 1 and 2 for two axial positions of the nut;
• FIG. 4 is a schematic diagram of the cable jack of the invention, the angles of the cables having been exaggerated;
• Figure 5 is a block diagram of a variant of the cable jack of the invention, with helical groove pulleys, the angles of the cables having been exaggerated.
• the cable jack of the invention comprises a frame 1 on which a screw 2 is rotatably mounted along an axis X while being rotated, here by an electric motor 3.
• a nut 4 cooperates with the screw 2 and is associated with an anti-rotation device 5 comprising two arms 6 which extend on either side of the nut 4 to carry rollers 7 (only one is visible here). ) which are mounted rotating about a Y axis normal to the axis X.
• the rollers 7 are engaged in longitudinal slots 8 which are formed in the frame and which extend parallel to the axis X.
• the Y axis passes substantially in the center of the nut 4.
• the nut moves axially under the effect of rotation the screw, without turning around the X axis.
• angular deviations are allowed around the Y axis, but also around a Z axis normal to the X and Y axes.
• the nut 4 comprises coupling means 9 of two cables 10 extending on either side of the nut 4 substantially symmetrically with respect to the axis X.
• the coupling means comprise two double clevises. (only one is visible here) which extend on both sides of the nut 4.
• the cables 10 are each wound around the respective pulleys 11 with a helical groove, the two pulleys 11 being integral with one and the same shaft 12 rotatably mounted along an axis parallel to the Z axis.
• the shaft 12 is mounted directly on the frame 1, but it could be remote from it.
• the shaft 12 forms the axis of a joint (for example a phalanx or an arm segment).
• the pulleys 11 are thus called articular pulleys
• the helical grooves of the articular pulleys 11 extend in opposite directions, as is more visible in FIGS. 3A and 3B, on which it is observed that the cables are not quite parallel to the axis. X, but are inclined with respect to the axis X of a small angle a corresponding to the angle ⁇ of the helical grooves.
• the two cables 10 being inclined at opposite angles, the lateral forces generated by the two cables 10 are canceled by symmetry.
• This angle should be constant during the movements of the nut 4, to ensure alignment of the cable with the groove of the pulley articular 11 associated with the winding point, so as to minimize the risk of wear of the cable and flanges of the groove.
• the shaft 12 is thus rotated as soon as traction is exerted on the cables by displacement of the nut 4.
• the cables 10 are held taut, for example by arranging the cables in a loop between two pulleys (as in FR2809464), or, if only a one-way action is required, by means of a tension spring.
• the cables 10 should be stretched by winding them not only on the articular pulleys 11, but on the return pulleys 13 which are both integral with one and the same return shaft 14 mounted here rotating on the frame 1 (opposite the articular shaft 12) about an axis parallel to the axis of rotation of the articular shaft 12.
• the return pulleys 13 here have helical grooves .
• the cylinder of means for rotational connection between the two shafts for example toothed belts, chains) realizing the condition of proportionality of the rotational speeds of the two shafts.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Robotics (AREA)
• Transmission Devices (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=48656131

Family Applications (1)

Country Status (4)

Families Citing this family (22)

Citations (1)

Family Cites Families (5)

• 2013
  • 2013-04-05 FR FR1353089A patent/FR3004230B1/fr active Active
• 2014
  • 2014-03-28 WO PCT/EP2014/056355 patent/WO2014161796A1/fr active Application Filing
  • 2014-03-28 US US14/777,922 patent/US10035260B2/en active Active
  • 2014-03-28 EP EP14714678.1A patent/EP2981739A1/de not_active Withdrawn

Patent Citations (1)

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