Robotic arm

• US 20040099081A1
• Filed: 11/12/2002
• Published: 05/27/2004
• Est. Priority Date: 05/18/2000
• Status: Abandoned Application

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Riwan, Alain, Ponsort, Dominique
• Application Number:
  US10/276,354
• Publication Number:
  US 20040099081A1
• Time in Patent Office: Days
• US Class Current: 74/490.01
• CPC Class Codes: B25J 13/02 Hand grip control means handles or pedals for crane control B66C13/56; for measuring the force applied to control members G01L5/22; hand-held casings for switching devices, e.g. joy-sticks H01H9/0214
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02
• CPC Class Codes: Y10T 74/20305 Robotic arm

Abstract

This master arm comprises a wrist (6) held at a constant global inclination to achieve excellent decoupling of translation controls accomplished by moving segments (3, 4) and rotation controls, accomplished by turning the wrist. The operator'"'"'s task is facilitated and kinetic singularities are almost entirely eliminated. One special embodiment comprises a wrist holder (5) and a special link (18 to 22) that connects the wrist holder to a fixed base; and moving elements (7, 8, 9) of the wrist (6) have hinge pins meeting at a point (0). Thus, the wrist (6) is balanced in rotation and applies a constant force on the segments (3, 4) of the arm, so that they can easily be balanced by a static feedback means. Therefore, the arm can remain in a stable position even when it is released.

Claims

1. Control arm comprising a segments train (3, 4) finishing on a base (1), and a wrist (6, 106) articulated to the segments train at an articulation axis (X4, X104), characterized in that the segments train (3, 4) is made such that the angle between the articulation axis (X4, X104) and a fixed plane is held constant.

2. Control arm according to claim 1, characterized in that the plane is horizontal, the train is composed of segments (3, 4) connected to each other and to the base through pivots (X2, X3) with a horizontal axis and the base is connected to a fixed element (2) through a pivot (X1) with a vertical axis.

3. Control arm according to either of claims 1 or 2, characterized in that the wrist is articulated to the segments train by a wrist holder (5), and that a return means (18 to 22) keeps the angle between the wrist holder and a fixed plane constant.

4. Control arm according to any one of claims 1 to 3, characterized in that the return means comprises a sequence of pulleys (18, 20, 22) arranged at a sequence of articulation pivots (X2, X3, X4) of the segments (3, 4) of the train, from the base (1) as far as the wrist holder (5), the belts (18, 21) being tensioned between pairs of pulleys forming a chain parallel to the segments, the pulleys turning freely, except for two end pulleys that are fixed to the base (1) and the wrist holder (5) respectively.

5. Control arm according to claims 1 to 4, characterized in that at least some of the segments are balanced by spring devices (12, 13).

6. Control arm according to claim 1, characterized in that the segments (3, 4) of the train are connected to each other and the wrist by articulations of axes that are all parallel (X2, X3, X104).

7. Control arm according to any one of claims 1 to 6, characterized in that the wrist (6, 106) is composed of elements articulated to each other and balanced about the articulation axis (X5, X104).

8. Control arm according to any one of claims 1 to 6, characterized in that the wrist is composed of elements articulated about axes (X6, X7, X106, X107) that are concurrent at a concurrent point (O) in line with the articulation axis (X5, X104).

9. Control arm according to claim 8, characterized in that the concurrent point (O) is located in the middle of a wrist operating handle (7, 107).

10. Control arm according to claim 8 or 9, characterized in that the concurrent point (O) is aligned with a main portion of one of the segments (104), the said segment also comprising a laterally transferred portion (140) to which the wrist (106) is articulated.

11. Control arm according to claim 10, characterized in that the transferred portion (140) is mounted free to pivot between two opposite and symmetric positions on the main portion of the segment (104).