Electrostatic printing machine with improved web-developing system
US4173945A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 27, 1975 |
| Grant date | Nov 13, 1979 |
| Priority date | — |
| Expiry date | Feb 27, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/11
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrostatic printing machine of the type having means for applying fluid toner material to a surface of a web of print material includes a toner fountain and pump for pumping toner into the fountain from a body of toner. A vacuum channel member extends transversely of the path of movement of the web for removing toner from the surface. The vacuum channel member is formed with an upwardly directed open cavity surrounded by walls which terminate at their upper end edges in substantially a common plane for supporting the web thereacross substantially sealing the cavity when the web is so located. A flow passage is formed to lead fluid toner out of the cavity from below and flow-operated vacuum means in the form of an aspirator is disposed on the discharge side of the pump and coupled in fluid communication to the flow passage, the vacuum means being further disposed and arranged to pass a flow of toner therethrough in a manner serving to apply a suction to the cavity for withdrawing toner material from the vacuum cavity via the flow passage therein, the suction being applied to a degree responsive to the rate of passing toner through the vacuum means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.