Browse Prior Art Database

Capstan, Torque and Speed Control

IP.com Disclosure Number: IPCOM000086285D
Original Publication Date: 1976-Aug-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Cachon, RP: AUTHOR [+2]

Abstract

In orienting objects into a predetermined and fixed orientation, for example, such as a semiconductor wafer 10 illustrated in the drawing, it is conventional practice to rotate the wafer until a notch 11 in the wafer 10 engages for example, a notch roller 12. Conventionally, the capstan is directly driven as by a belt, idler or gear mechanism and the torque and speed of the capstan is thus variable depending upon load conditions. The apparatus illustrated helps to maintain a constant speed of rotation of the capstan 13, while maintaining the torque at a constant level.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 2

Capstan, Torque and Speed Control

In orienting objects into a predetermined and fixed orientation, for example, such as a semiconductor wafer 10 illustrated in the drawing, it is conventional practice to rotate the wafer until a notch 11 in the wafer 10 engages for example, a notch roller 12. Conventionally, the capstan is directly driven as by a belt, idler or gear mechanism and the torque and speed of the capstan is thus variable depending upon load conditions. The apparatus illustrated helps to maintain a constant speed of rotation of the capstan 13, while maintaining the torque at a constant level.

The capstan or wheel 13 is centrally mounted for rotation by a ball bearing, not shown, on the capstan support 14 and nested therein so that the periphery of the capstan 13 intersects a bore 15, which extends through the support 14 tangentially to the periphery of the capstan 13. The bore 15 has an air inlet port 16 and an air outlet or sense port 17, so that air flowing in the direction of the arrow into the input port 16 of the bore 15 effects rotation of the capstan 13, the residual air emitting from the outlet port 17. As described below, the air leaving the bore 15 serves to effect control of the speed and torque of the capstan 13.

As shown, air enters the system through a main supply line 18 and passes through a variable restrictor 19 and then through port number 5 of the normally open valve 20. In this manner, air is supplied to the input port 16 of the bore 15 effecting rotation of the capstan 13. Air passing through the bore 15 leaves the sense...