Methods for picking and placing workpieces into small form factor hard disk drives

• US 7,549,204 B1
• Filed: 11/30/2005
• Issued: 06/23/2009
• Est. Priority Date: 11/30/2005
• Status: Expired due to Fees

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Vangal-Ramamurthy, Jambunathan, Butler, Walter W.
• Primary Examiner(s): Hong; John C
• Application Number:
  US11/289,922
• Time in Patent Office: 1,301 Days
• Field of Search: 294/070.2, 294/070.3, 294/070.4, 294/070.5, 294/070.8, 294/070.9, 294/070.1, 294/06, 295/250.1, 295/250.2, 295/251.1, 297/03, 297/07, 297/09, 297/10, 297/12, 297/43, 292/40, 901/14, 901/30
• US Class Current: 29/407.02
• CPC Class Codes: B23P 19/007 Picking-up and placing mechanisms
• CPC Class Codes: B23P 19/06 Screw or nut setting or loosening machines
• CPC Class Codes: B23P 19/066 by electrical means
• CPC Class Codes: B23P 19/10 Aligning parts to be fitted together
• CPC Class Codes: Y10T 29/49025 Making disc drive
• CPC Class Codes: Y10T 29/49027 Mounting preformed head/core onto other structure
• CPC Class Codes: Y10T 29/49766 torquing threaded assemblage or determining torque herein
• CPC Class Codes: Y10T 29/49769 Using optical instrument [excludes mere human eyeballing]

Abstract

A method of driving screws may include steps of providing a robotically controlled screw driver, a servo motor assembly for moving the screw driver, at least one controller for controlling the screw driver and the servo motor assembly, and a machine vision assembly coupled to the controller. The screw may be coupled to the screw driver, and the screw may be aligned with a threaded hole using the machine vision assembly and the controller to control the servo motor assembly, such that the screw is aligned with a center of the threaded hole. The aligned screw may then be driven into the threaded hole.

Claims

1. A method of driving screws, comprising:

providing a robotically controlled screw driver, a servo motor assembly for moving the screw driver, at least one controller for controlling the screw driver and the servo motor assembly, and a machine vision assembly coupled to the controller;

generating an image of a screw using the machine vision assembly;

aligning the screwdriver to the screw using the image;

coupling the screw to the screw driver;

generating an image of a threaded hole using the machine vision assembly;

aligning the screw with the threaded hole based at least in part upon the image using the controller to control the servo motor assembly, such that the screw is substantially aligned with a center of the threaded hole; and

driving the aligned screw into the threaded hole.

2. The method of claim 1, wherein the coupling is carried out using vacuum from a vacuum assisted nozzle to pick up the screw from a screw feeder station.

3. The method of claim 1, wherein the driving includes monitoring a torque exerted on the screw by the screw driver during the driving.

4. The method of claim 3, further comprising designating the driving as failed when the torque exerted on the screw exceeds a predetermined torque threshold.

5. The method of claim 4, further comprising retrieving and disposing of the screw when the torque exerted on the screw exceeds the predetermined torque threshold, and performing the coupling.

6. The method of claim 1, wherein the driving includes monitoring an angular rotation imposed on the screw during the driving.

7. The method of claim 6, further comprising designating the driving as failed when the angular rotation imposed on the screw during the driving exceeds a predetermined angular rotation threshold.

8. The method of claim 7, further comprising retrieving and disposing of the screw when the angular rotation imposed on the screw during the driving exceeds the predetermined angular rotation threshold, and performing the coupling.

9. The method of claim 1, further including detecting a first thread of the screw prior to carrying out the driving.

10. The method of claim 9, wherein the driving drives the screw in a first direction, and wherein the detecting includes driving the screw in a second direction to detect the first thread.

11. The method of claim 1, wherein the machine vision assembly is stationary.

12. The method of claim 1, wherein the machine vision assembly is coupled to the servo motor assembly.

13. The method of claim 12, further comprising stopping the servo motor assembly when the machine vision assembly is over the threaded hole until the machine vision assembly has finished generating the image of the threaded hole.

14. The method of claim 12, wherein generating the image of the threaded hole includes imaging the threaded hole while the servo motor assembly is in motion.