Browse Prior Art Database

Synchronization of Two or More Cyclic Printers

IP.com Disclosure Number: IPCOM000095381D
Original Publication Date: 1965-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Terry, DW: AUTHOR

Abstract

The arrangement for simultaneous high-speed operation of two printers by allowing the machines to free run. This occurs except when a too far out-of-sync condition is recognized. The machines normally run in cycles controlled by a clutch and mechanisms which latch up the clutch after each cycle. This takes place unless a positive new cycle signal is received. Provision is built into the too far out-of-sync logic to assure that a latchup, once begun, is not reversed by an incoming character at a time during which the clutching mechanisms would be physically injured by the reversal.

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Synchronization of Two or More Cyclic Printers

The arrangement for simultaneous high-speed operation of two printers by allowing the machines to free run. This occurs except when a too far out-of-sync condition is recognized. The machines normally run in cycles controlled by a clutch and mechanisms which latch up the clutch after each cycle. This takes place unless a positive new cycle signal is received. Provision is built into the too far out-of-sync logic to assure that a latchup, once begun, is not reversed by an incoming character at a time during which the clutching mechanisms would be physically injured by the reversal.

When one printer cycle is terminated the cycle of the other printer is also terminated. After such termination both printers are then started and run free as long as reasonably possible. In practice, two printers of the same design tend to run at close to the same speed once their cycle shafts accelerate to normal speed. On the other hand wide variations occur during the clutching and starting of a cycle.

The above arrangement a modification of an accounting machine requires two printers of the IBM I/O Selectric typewriter type. One printer is at an accounting machine and the other is at a magnetic ledger card unit. Termination of a cycle is automatic, unless a cycle clutch latch 3 is positively pulled to let the next cycle begin.

Timing cam 5 and cam follower 7 are situated on the driven shaft. Cam 5 produces an up signal during every stage of a cycle, including a fully-latched condition during which new data for a subsequent cycle can be received. During times a few milliseconds before the completion of a cycle and...