Browse Prior Art Database

Positioning Drive Mechanism

IP.com Disclosure Number: IPCOM000077650D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Yakubowski, C: AUTHOR

Abstract

The apparatus illustrated is particularly adapted for accurate positioning of trays or the like carrying small parts, such as semiconductor chips, where a slim profile of the drive is necessary, so that a large number of such drives may be utilized to bring small parts to a common pickup or dispense location.

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Positioning Drive Mechanism

The apparatus illustrated is particularly adapted for accurate positioning of trays or the like carrying small parts, such as semiconductor chips, where a slim profile of the drive is necessary, so that a large number of such drives may be utilized to bring small parts to a common pickup or dispense location.

Referring to Fig. 1, because of random positioning and high-speed requirements, a closed-loop servo control was selected to satisfy such requirements. A servomotor 10 is shown directly connected to a high-helix lead screw 15. The servomotor is also connected, on its opposite side, to a tachometer 11 which acts as a DC voltage generator that is connected to a multiturn potentiometer 12, which is utilized to control the speed of the servomotor and thus of the lead screw 15. The lead screw is mounted in a frame, not shown, and with suitable bearings such as duplex, back-to-back preloaded and axially contained bearings, both axial and radial play may be eliminated. The high-helix lead screw is a five start, one inch lead, rolled thread screw with a helix angle of approximately 45 degrees. Because the servomotor utilized may be of a low-torque type, and the coupling between the servomotor and high-helix lead screw 15 is direct, the drive linkages must be designed with low inertial and frictional loads.

To permit movement of a slide tray 20 or the like axially of the lead screw 15, a pin lock 21, which may be an eccentric, permits fine adjustment of the slide tray 20, relative to the lead screw, while providing a coupling of the tray to a lead screw nut 16 which is slideably mounted by lapped integral journal bearings 17 and 18 on a guide shaft 19. As il...