Patent ID: 6408252
Filing Date: 2002-06-18
Classification: B25J,G05B

Abstract:
A displacement measuring device for a robot having an end-point, said measuring device comprising;a housing; an elongate shaft mounted within said housing; a drum having a central axis, a central throughhole extending along said central axis through said drum and capable of accepting the shaft, the drum being mounted on the shaft and the drum having a generally cylindrical outer surface; a elongate member having a fixed width, a first end and a second end, the first end attached to the outer surface of the drum and the second end attached to the end-point, the elongate member being coilable about the drum; displacement means for displacing the drum in a direction along said central axis relative to the coiling of the elongate member about the drum thereby preventing the elongate member from overlapping itself; and rotation measuring means for measuring the rotation of the drum about the drum central axis, whereby the rotation of the drum is translated into the linear displacement of the elongate member and thusly the distance from the measuring device to the end-point.