Robot compliance device

A compliance device for a robot to isolate the robot from reaction loads induced by an operation of a tool used by the robot, and to return the tool to a predetermined home position after a tool operation, comprising:

• a fluid cylinder having an end for attachment to the robot and a free end;
• a tool isolation assembly for permitting reaction movement by the tool during tool operations, the tool isolation assembly being independent of and spaced apart form the free end of the fluid cylinder;
• a position locator means for returning the tool isolation assembly to the predetermined home position and having a first end rigidly affixed to the fluid cylinder, an intermediate portion that passes through an aperture in the tool isolation assembly and, a second end that permits limited movement of the tool isolation assembly in any direction except past the second end of the position locator means;
• the second end of the position locator means having a surface adjacent the aperture in the tool isolation assembly, the surface including position index means for cooperating with complementary position index means on a surface of the tool isolation assembly that includes the aperture;
• and
• at least one piston rod that extends through the free end of the cylinder for applying mechanical pressure to the position locator end of the tool isolation assembly to force the tool isolation assembly into contact with the position locator means so that the position index means on the surface of the position locator means and the complementary position index means on the surface of the tool isolation assembly cooperate to move the tool isolation assembly to the predetermined home position when pressurized fluid is injected into the cylinder and the at least one piston rod is extended.

A compliance device for a robot, comprising:

• a fluid cylinder having first and second ends, a bore that communicates with the first and second ends, a piston that is forcibly reciprocally movable within the bore, and a tubular piston rod affixed to the piston and extending through the second end of the fluid cylinder;
• a tool isolation assembly for permitting reaction movement of a tool during tool operations, the tool isolation assembly being independent of and spaced apart form the second end of the fluid cylinder, and having a position locator end adjacent the fluid cylinder and a tool attachment end remote from the fluid cylinder;
• a position locator for cooperating with the position locator end to position the tool isolation assembly in a predetermined home position, the position locator having a shaft with a first end that is rigidly affixed to the fluid cylinder and passes through an aperture in the position locator end of the tool isolation assembly and a cone-shaped end that permits limited movement of the tool attachment end of the tool isolation assembly in any direction except past the cone-shaped end;
• the cone-shaped end of the position locator having a surface adjacent the position locator end of the tool isolation assembly, the surface including equally spaced-apart detent grooves located between inclined plane surfaces for cooperating with complementary rollers on an adjacent surface of the position locator end of the tool isolation assembly;
• and
• the tubular piston rod that extends through the second end of the cylinder contacts the locator end of the tool isolation assembly to force the tool isolation assembly into contact with the cone-shaped end of the position locator so that the detent grooves on the cone-shaped end of the position locator and the rollers on the position locator end cooperate to urge the tool isolation assembly to a predetermined home position when pressurized fluid is injected into the fluid cylinder and the tubular piston rod is extended.