Finger assembly having a talon and barrel cam actuation

Patent metadata

Field	Value
Publication number	US-10654176-B2
Application number	US-201715799741-A
Country	US
Kind code	B2
Filing date	Oct 31, 2017
Priority date	Oct 31, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

Finger assemblies at the end of a robotic arm end effector includes talon that are retractable. Retraction may be accomplished by a vertical or horizontal barrel cam, a paddle and spin assembly, and/or a resilient plate.

First claim

What is claimed is:

1. A finger assembly for use at the end of a robotic arm, the finger assembly comprising:
an end effector mount adapted for mounting to the robotic arm;
a finger body coupled to and extending downwardly from the end effector mount, the finger body having an anti-slip contact face, the contact face being adapted for contacting and at least partially supporting the load from an item while the item is being lifted by the robotic arm; and
a retractable talon coupled at a lowermost point of the finger body, the talon is pivotable relative to the contact face between an extended position in which the talon extends outwardly from the contact face of the finger body and a retracted position in which the talon is recessed relative to the contact face of the finger body; the talon in the extended position is adapted to at least partially support the load from an item lifted by the robotic arm.

2. A finger assembly for use at the end of a robotic arm, the finger assembly comprising:
an end effector mount adapted for mounting to the robotic arm;
a finger body coupled the end effector mount, the finger body having an anti-slip contact face;
a retractable talon coupled to the finger body, the talon has an extended position in which the talon extends outwardly from the contact face of the finger body and a retracted position in which the talon is recessed relative to the contact face of the finger body; the talon in the extended position is adapted to at least partially support a load from an item lifted by the robotic arm; and
a barrel cam having a barrel cam body pivotably coupled to the finger body, the barrel cam body being operatively connected to the talon such that actuation of the barrel cam pivots the talon between its retracted and extended position.

3. The finger assembly of claim 2 wherein the barrel cam includes a barrel cam body and a cam follower, the barrel cam body including one of a groove and a ridge that is configured for rotation about a barrel cam rotational axis in response to engagement with the cam follower, whereby rotation of the barrel cam body about the barrel cam rotational axis in a first direction moves the talon to the extended position and rotation of the barrel cam body about the barrel rotational axis in a second direction opposite to the first direction moves the talon to the retracted position.

4. The finger assembly of claim 3 wherein the barrel cam is horizontally oriented such that the barrel rotational axis is horizontal, and wherein the cam follower is stationary relative to the finger body and the barrel cam body rotates relative to the finger body.

5. The finger assembly of claim 4 wherein the cam follower is a pin that is fixed relative to the finger body and the cam body is the groove.

6. The finger assembly of claim 4 wherein the talon is rigidly attached to a distal end of the barrel cam body such that rotation of the barrel cam body rotates the talon.

7. The finger assembly of claim 6 wherein a shaft of the barrel cam extends laterally outwardly from the finger body such that axial movement of the shaft translates the barrel cam body and rotates the barrel cam body and talon between the extended position and retracted position.

8. The finger assembly of claim 6 further comprising a rotational compliance mechanism that includes a shoulder bolt connected between the finger body and the end effector mount, a pair of bearings mounted on a shaft of the shoulder bolt, a pair of thrust bearings mounted on the shaft of the shoulder bolt, and a spring biasing the finger body to an at-rest state.

9. The finger assembly of claim 2 wherein the barrel cam includes a barrel cam body and a cam follower, the barrel cam body is vertically oriented such that the barrel rotational axis is vertical, and the talon is rigidly connected to a lower end of the barrel cam body such that the talon pivots with the barrel cam body.

10. The finger assembly of claim 9 wherein the cam follower is a pin that is fixed relative to the finger body and the cam body is a groove, wherein the cam follower is stationary relative to the finger body and the barrel cam body is rotatable relative to the finger body, and the contact face is flat.

11. The finger assembly of claim 9 wherein the talon is rigidly attached to a distal end of the barrel cam body such that rotation of the barrel cam body rotates the talon.

12. The finger assembly of claim 9 further comprising a bumper extending downwardly from a bottom end of the finger body and a spring biasing the bumper downwardly relative to the finger body, the bumper being operatively connected to the barrel cam body and the bumper being adapted for translation relative to the cam follower such that upward translation of the bumper and the barrel cam body relative to the cam follower causes rotation of the talon from its retracted position to its extended position.

13. The finger assembly of claim 12 further comprising a lock for retaining the bumper in a locked position when the talon is in the extended position, the lock being adapted to be engaged upon the finger body face being engaged with the item, the lock being spring biased toward an unlocked position such that upon disengagement of the finger body face with the item, the lock moves to the unlocked position.

14. The finger assembly of claim 13 wherein the lock includes a spring-biased locking plate and detent for holding the bumper in the locked position.

15. The finger assembly of claim 12 further comprising a first magnet affixed to the finger body and a second magnet affixed to a locking plate, the magnets engaging one another when the talon is at least one of the retracted position and the engaged position.

16. The finger assembly of claim 12 further comprising a rotational compliance mechanism that includes a shoulder bolt connected between the finger body and the end effector mount, a pair of bearings mounted on a shaft of the shoulder bolt, a pair of thrust bearings mounted on the shaft of the shoulder bolt, and a spring biasing the finger body to an at-rest state.

17. A method of actuating opposing robotic arms to pick up at item, comprising the steps of:
(i) moving a pair of opposing robotic arms relative to an item such that finger assemblies at a distal end of the arms are in contact with or in close proximity to a base surface on which the item resides;
(ii) rotating a vertically-oriented barrel cam body of each finger assembly in a first rotational direction relative to contact faces of the finger assemblies to pivot a talon beneath the item,
(iii) after extending the talons, moving the robotic arms to put the contact faces and the talons into contact with the item to lift the item; and
(iv) after lifting the item, rotating the barrel cam in a second rotational direction that is opposite the first rotational direction to retract the talon.

18. The method of claim 17 wherein the rotating step (i) includes translating a barrel cam body of the barrel cam relative to a cam follower that is fixed relative to a finger body, the talon being rigidly attached to the cam body follower such that rotating the barrel cam body extends the talon.

19. The method of claim 18 wherein the barrel cam body is vertical and the rotating step (i) includes engaging a bumper on the distal end of the finger assembly against the base surface and thereby moving the bumper against a spring bias to translate the barrel cam body.

20. The method of claim 18 wherein the barrel cam body is horizontal and the

Assignees

• Amazon Tech Inc

Inventors

• Jonas Jude Royston
• Claretti Ennio
• Juranovits Justin Thomas
• Marchese Andrew D

Classifications

• B25J15/0616

  with vacuum · CPC title

• B25J15/0028

  with movable, e.g. pivoting gripping jaw surfaces · CPC title

• B25J15/0253

  comprising parallel grippers · CPC title

• B25J15/08

  having finger members (B25J15/02, B25J15/04 take precedence) · CPC title

• B25J9/1694

  characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion · CPC title