Browse Prior Art Database

Document Feeder Air System

IP.com Disclosure Number: IPCOM000038468D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Littlejohn, NH: AUTHOR

Abstract

A constant-flow air system is provided for a copier's original document feeder. Total system airflow rate remains nearly constant under the various system operating conditions of the document feeder. The document feeder has six different airflow paths. Three paths require vacuum, and three require pressure. Five of the six air paths operate at high resistance and low flow. The remaining path operates at low resistance and high flow. For the five high resistance paths, the total airflow volume required by the vacuum paths equals the total flow required by the pressure paths. A common blower 10 is used for all six air paths. To compensate for different flow resistances, a restrictor 11 is used between document belt 12 and the blower.

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Document Feeder Air System

A constant-flow air system is provided for a copier's original document feeder. Total system airflow rate remains nearly constant under the various system operating conditions of the document feeder. The document feeder has six different airflow paths. Three paths require vacuum, and three require pressure. Five of the six air paths operate at high resistance and low flow. The remaining path operates at low resistance and high flow. For the five high resistance paths, the total airflow volume required by the vacuum paths equals the total flow required by the pressure paths. A common blower 10 is used for all six air paths. To compensate for different flow resistances, a restrictor 11 is used between document belt 12 and the blower. This reduces the pressure seen by the document belt and also balances the flow in the three vacuum flow paths. Likewise, an air-bleed path 13 is used on the pressure side to vent the unused air to atmosphere and balance the pressure side flows. Near constant flow under varying operating conditions is achieved as follows: When a sheet of paper closes the airflow to picker 14, for instance, the flow through entry belt 15 and document belt 12 will increase, and will almost completely compensate for the flow which was lost in picker 14. The amount of flow compensation is large with this system because the document belt flow path has a very low resistance to flow even with restrictor 11 in the system. Thus, both t...