Patent ID: 8608398

Claim:
A spherical joint with internal brake, comprising: an outer spherical retaining shell having an outer wall and an internal wall, the retaining shell defining an aperture and a plurality of holes; first and second internal spherical sectioned members disposed inside the outer retaining shell, the sectioned members being in contact with the internal wall of the outer retaining shell; an actuator having a dual piston, the piston having opposed external ends, the external ends of the dual piston being attached to the first and second internal spherical sectioned members, respectively; third and fourth internal spherical sectioned members attached to the actuator, the fourth internal spherical sectioned member having a radially extending channel formed therein, the channel having an open end; an elongate member attached to the third internal spherical sectioned member, the elongate member extending through the shell aperture; a control line operably connected to the actuator, the control line being adapted for relaying braking and release commands from a controller, the actuator responsively varying friction between the first and second spherical sections and the internal wall of the spherical retaining shell, thereby selectively braking and alternately allowing rotational motion of the internal spherical sections and the elongate member relative to the outer spherical retaining shell; and a light source mounted within the radially extending channel formed in the fourth internal spherical sectioned member, whereby light produced by the light source and passing through the open end of the channel and one of the holes in the outer shell when aligned therewith provides an external visual indication of a position of the fourth internal spherical sectioned member with respect to the outer retaining shell.