Browse Prior Art Database

Contour Controlled Electrostatic Clutch

IP.com Disclosure Number: IPCOM000098959D
Original Publication Date: 1962-Mar-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Schaaf, RL: AUTHOR

Abstract

This electrostatic clutch has bands to actuate a row of print hammers and utilizes fewer band drivers than required previously.

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Contour Controlled Electrostatic Clutch

This electrostatic clutch has bands to actuate a row of print hammers and utilizes fewer band drivers than required previously.

The clutch comprises insulating drum 1, surrounded by a semiconductive clutching surface 2. Drum 1 contains one or more helical electrically conductive strips 3 in internal contact with surface 2. A row of axially spaced bands 4A...4C, etc., disposed traverse to the axis of the drum 1 have about 90 degrees of contact with external portions of surface 2. One end of each of band 4A, etc., is connected to driver circuit 5. The other end of each band actuates a print hammer, such as shown in U. S. Patent 2,909,996.

Each conductive strip 3 is wound axially about drum 1 such that, when band 4A is above the strip, bands 4B and 4C are not. Consequently, a printer with N print positions requires only N/X drive circuits. Bands 4A, 4B and 4C connect to only one drive circuit 5. When it is desired to select any one of a set of X print hammers among an entire row of N hammers, all the bands in the set are pulsed by one driver. However, only one band is actuated since a particular conductive strip 3 is under only one of the bands of the set at a time. When the conductive strip 3 advances to the adjacent band in the set, that band is actuated by the driver without actuating the remaining bands in the set.

The clutch, in coincidence with the drive pulses applied to the clutch bands, determines:
1. The length of ti...