Robotic tool change mechanism

• US 5,044,063 A
• Filed: 11/02/1990
• Issued: 09/03/1991
• Est. Priority Date: 11/02/1990
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Voellmer, George M.
• Primary Examiner(s): Howell, Daniel W.
• Application Number:
  US07/608,657
• Time in Patent Office: 305 Days
• Field of Search: 29/568, 901/30, 901/31, 901/39, 901/41, 294/86.4
• US Class Current: 483/59
• CPC Class Codes: B23Q 3/15553 Tensioning devices or tool holders, e.g. grippers driving working-spindles and adjusting or stopping them in a predetermined angular position B23Q5/20; securing milling cutters to the driving spindle in a given angular position B23C5/26
• CPC Class Codes: B25J 15/0491 comprising end-effector racks
• CPC Class Codes: Y10S 483/901 Robot end effectors
• CPC Class Codes: Y10S 483/902 Tool grippers
• CPC Class Codes: Y10T 483/1809 Matrix including means to latch tool

Abstract

An assembly of three major components including a wrist interface plate which is secured to the wrist joint of a robotic arm, a tool interface plate which is secured to each tool intended for use by the robotic arm, and a tool holster for each tool attached to the interface plate. The wrist interface plate and a selected tool interface plate are mutually connectable together through an opening or recess in the upper face of the interface plate by means of a notched tongue protruding from the front face of the wrist interface plate which engages a pair of spring-biased rotatable notched wheels located within the body of the tool interface plate. The tool holster captures and locks onto the tool interface plate by means of a pair of actuation claws including a locking tab and an unlocking wedge which operate respective actuation bosses on each of the notched wheels in response to a forward and backward motion of the tool interface plate as a result of motion of the robotic arm to either park the tool or use the tool.

Claims

1. Tool changer apparatus for a robotic system, comprising:

first interface means attachable to a robotic arm;

second interface means attachable to a tool to be used by the robotic arm;

stowage means, including actuation means, for receiving and holding said second interface means when the respective tool is not in use;

said first and second interface means further including means for mutually engaging each other in response to movement from and to said stowage means, said means for engaging each other comprising a member including at least one notch therein extending from one of said first and second interface means, and a recess and notch engaging member in the other of said first and second interface means, said notch engaging member being movable in and out of said at least one notch in response to operation by said actuation means of said stowage means;

said member including at least one notch comprises a tongue extending from said first interface means and wherein said recess and notch engaging means are located in said second interface means;

said first interface means comprises a wrist interface plate attachable to an outer end portion of the robotic arm and said second interface means comprises a tool interface plate fastened to said tool;

said stowage means comprises a holster in the form of a yoke member having bifurcated outwardly extending arms for engaging said tool interface plate, and

said notch engaging means comprises a wheel rotatable in and out of said at least one notch of said tongue.

2. The tool changer apparatus of claim 1 wherein said tongue comprises a generally flat plate member including a pair of notches located in opposite side edges thereof.

3. The tool changer apparatus of claim 2 and wherein said notch engaging means further comprises a second wheel, said wheels comprise a pair of spring biased wheels located adjacent said recess and being respectively rotatable into the notches of said tongue by said actuation means of said holster. 17

4. The tool changer apparatus of claim 3 wherein said pair of wheels include peripheral edges which extend over said recess to respectively engage the pair of notches in said tongue, said wheels additionally including a respective notch matching the size of said recess, and being rotated by said actuation means to align said notches with said recess in a stowed position of said tool interface plate on said holster so as to receive said tongue of said wrist interface plate.

5. The tool changer of claim 4 wherein each of said wheels includes an actuation boss on one face thereof and wherein each arm of said holster includes an actuation claw for contacting a respective actuation boss.

6. The tool changer of claim 5 wherein each said actuation claw is located on an outer portion of a respective inner side surface of said arm of the holster and including a forwardly positioning locking tab having a front camming surface for engaging said actuation boss and rotating said notched wheel in a first direction and a rearwardly positioned unlocking wedge having a hook portion for engaging said actuation boss and rotating said notched wheel in a second direction.

7. The tool changer of claim 6 wherein said tool interface plate includes a pair of side channels through which a respective actuation boss projects, and wherein said side channels include contact surfaces for sliding on and off of said arms of the holster.

8. The tool changer of claim 5 wherein each of said wheels further includes a raised wedge type region adjacent a respective notch therein for engaging the tongue at each notch of said pair of notches.

9. The tool changer of claim 5 wherein each of said notched wheels are coupled to over center spring members for biasing between said wheels at two limiting end positions.

10. Tool changer apparatus for a robotic system, comprising:

first interface means attachable to a robotic arm;

second interface means attachable to a tool to be used by the robotic arm;

stowage means, including actuation means, for receiving and holding said second interface means when the respective tool is not in use;

said first and second interface means further including means for mutually engaging each other in response to movement from and to said stowage means, said means for engaging each other comprising a member including at least one notch therein extending from one of said first and second interface means, and a recess and notch engaging member in the other of said first and second interface means, said notch engaging member being movable in and out of said at least one notch in response to operation by said actuation means of said stowage means;

said member including at least one notch comprises a tongue extending from said first interface means and wherein said recess and notch engaging means are located in said second interface means;

said first interface means comprises a wrist interface plate attachable to an outer end portion of the robotic arm and said second interface means comprises a tool interface plate fastened to said tool;

said stowage means comprises a holster in the form of a yoke member having bifurcated outwardly extending arms for engaging said tool interface plate, and

said holster includes means for locking said tool interface plate in position thereon and where said wrist interface plate includes means for unlocking said tool interface plate therefrom to permit the removal of said tool interface plate from said holster.

11. The tool changer of claim 10 wherein said locking means comprises an upwardly biased plunger member located on the forward portion of each arm of said holster, said tool interface plate additionally including a pair of outwardly extending ear type members, each having a bore therein for receiving a respective plunger member when in a stowed position on said holster.

12. The tool changer of claim 11 wherein said wrist interface plate includes a pair of plunger member depression means, one on each outer end portion of said wrist interface for depressing said plunger member through the bores in the tool interface plate so that the tool interface plate can be slid from the arms of the holster.

13. The tool changer of claim 12 wherein said depression means comprise a pair of rounded end pin type members projecting from an outer face of said wrist interface plate.

14. The tool changer of claim 13 wherein said tongue is located between said pair of pin type members.