Robot and control system

• US 4,507,044 A
• Filed: 12/08/1981
• Issued: 03/26/1985
• Est. Priority Date: 12/08/1981
• Status: Expired

• Current Assignee: ZY Acquistion Corporation
• Original Assignee: Zymark Corp. (Revvity, Inc.)
• Inventors: Hutchins, Burleigh M., Abrahams, Louis, Dunlap, Raymond R.
• Primary Examiner(s): Valenza, Joseph E.
• Assistant Examiner(s): Underwood, Donald W.
• Application Number:
  US06/328,726
• Time in Patent Office: 1,204 Days
• Field of Search: 414/7, 414/589, 414/744 R, 414/744 A, 414/590, 414/591, 414/749, 414/751, 414/753, 254/283, 254/286, 254/334, 254/338, 187/27, 187/20, 74/89.2, 74/89.22, 74/469, 318/568, 318/67, 901/17, 901/21
• US Class Current: 414/744.3
• CPC Class Codes: B25J 18/02 extensible
• CPC Class Codes: B25J 9/041 Cylindrical coordinate type
• CPC Class Codes: B25J 9/104 with cables, chains or ribbons
• CPC Class Codes: Y10T 74/18848 with pulley

Abstract

A compact robot of the 3-axis type comprising a base-mounted motor control system with means to sense the position of a robot arm through a servo-system comprising position-sensing potentiometers mounted in the motor control system and a feed-back control system to co-ordinate the vertical and horizontal movement of a robot arm.

Claims

1. In a robot apparatus of the type comprising means to move a robot arm in a vertical direction, and in a horizontal direction substantially co-axial with said arm, and means to rotate said arm through a plane co-planar with said horizontal direction, the improvement wherein the means to move comprises motor means mounted on a horizontal turntable with winch means for operating horizontal cable means and vertical cable means, respectively, and the means to rotate comprises a turntable-rotating motor;

means with winch means for operating said turntable and said vertical cable means comprising a first cable means for moving said robot arm vertically, and first cable means being fastened at each end to an arm-holding bracket adapted to slide on vertical tracks and said first cable means being looped around a winch which is part of said winch means for operating the vertical cable means proximate the bottom of said track and around a pulley proximate the top of said track, and said horizontal cable means comprising a second cable means to move said arm horizontally through said bracket, said second cable means having ends of which are attached to said arm near the ends of said arm on opposite sides of said bracket; and

wherein the second cable means runs from one said cable end to a pulley in said bracket downwardly to a pulley mounted proximate the top of said vertical track, downwardly around a second pulley attached to said bracket and thence to the other of said cable ends.

2. A robot apparatus as defined in claim 1 wherein said motor means are direct current servo motors and wherein said cable means are steel cables.

3. A robot apparatus as defined in claim 1 wherein said motor means for moving said arm in vertical or horizontal directions is controlled by a motor control system including means to sense the vertical and horizontal position of said robot arm and sensing means comprising a potentiometer mounted on said turntable and forming means to measure the rotational position of each said winch means and connect said rotational position into an electrical signal which resulting signals are co-ordinated through a servo-system with one another to achieve a smooth movement of said robot arm.

4. A robot as defined in claim 1 wherein said arm is adapted to slide back-and-forth within said support bracket in a horizontal direction in response to a first motor and is adapted to move in vertical direction in response to a second motor which forms means to move said bracket, the improvement comprising motor control means whereby said first motor is operated at a speed of at least four times the maximum gear-shaped ratio of said second motor.

5. A robot as defined in claim 4 wherein the motor control system of said first motor comprises a signal inversion means allowing its operating speed to be determined, at least in part, by the control system for said second motor.

6. Apparatus as defined in claim 1 wherein each of said first cable means and said second cable means comprise two segments, each said segment having one end terminating on the winch about which each said cable is looped.