Abstract In dry copying machines utilizing particulate toner a particle conveying system including a plurality of pneumatic ducts and a blower with a vacuum-type pickup device attached to an inlet of the blower and positioned to remove loose particles from the copies as they egress from the copying machine, a centrifugal separator positioned in the pneumatic system to receive the air and particles from the vacuum pickup device and separate the particles from the bulk of the air, a particle settling chamber having baffles therein attached to the copying machine and receiving separated particles from the separator so as to return them to active use in the copying machine and further having an outlet duct attached to the blower to reduce the pressure therein slightly below atmospheric, and a filter assembly attached to the air outlet of the separator so that air leaving the separator is filtered prior to being returned to the atmosphere. The filter assembly is constructed from an extruded plastic housing having two sidewalls and a joining wall connected to provide a U-shaped cross section and a pleated filter element connected to the sidewalls opposite the joining wall and end walls formed of plastic while in its formable state and subsequently hardened to provide sealing engagement with the ends of said housing and pleated filter.
In copying machines utilizing particulate toner having a toner applying area therein, a pneumatic conveyance system comprising: a. pickup means, having an inlet positioned adjacent the toner applying area of the copying machine for removing loose toner particles from emerging copies, and an outlet; b. a particle settling chamber having at least some opening to atmosphere and having an inlet and an outlet, said settling chamber being positioned adjacent said copying machine in communication with the toner applying area; c. a pneumatic flow producing pump having an inlet and an outlet; d. centrifugal separating means having an inlet, a gas outlet and a scavenging-flow outlet; e. first conduit means, connected between the pump inlet, the outlet of the pickup means and the outlet of the particle settling chamber, for producing flow at sub-atmospheric pressure through the pickup means and flow at sub-atmospheric pressure through the particle settling chamber to prevent particles from escaping through said openings therein; f. second conduit means connected between the inlet of the centrifugal separating means and the pump outlet for conducting particles and gas from the pickup means and the particle settling chamber into the centrifugal separating means, said separating means acting to separate the majority of said particles from the main pneumatic flow, the main pneumatic flow egressing from said centrifugal separating means through said gas outlet and the separated particles egressing from said centrifugal separating means through said scavenging-flow outlet; and g. third conduit means connected between the scavenging-flow outlet and the inlet of the particle settling chamber for conducting separated particles from the centrifugal separating means into the particle settling chamber.
Claim 2
Dependent Claim
269 words
In copying machines utilizing particulate toner having a toner applying area therein, a pneumatic conveyance system comprising: a. pickup means, having an inlet positioned adjacent the toner applying area of the copying machine for removing loose toner particles from emerging copies, and an outlet; b. a particle settling chamber having at least some opening to atmosphere and having an inlet and an outlet, said settling chamber being positioned adjacent said copying machine in communication with the toner applying area; c. a pneumatic flow producing pump having an inlet and an outlet; d. centrifugal separating means having an inlet, a gas outlet and a scavenging-flow outlet; e. first conduit means, connected between the pump inlet, the outlet of the pickup means and the outlet of the particle settling chamber, for producing flow at sub-atmospheric pressure through the pickup means and flow at sub-atmospheric pressure through the particle settling chamber to prevent particles from escaping through said openings therein; f. second conduit means connected between the inlet of the centrifugal separating means and the pump outlet for conducting particles and gas from the pickup means and the particle settling chamber into the centrifugal separating means, said separating means acting to separate the majority of said particles from the main pneumatic flow, the main pneumatic flow egressing from said centrifugal separating means through said gas outlet and the separated particles egressing from said centrifugal separating means through said scavenging-flow outlet; and g. third conduit means connected between the scavenging-flow outlet and the inlet of the particle settling chamber for conducting separated particles from the centrifugal separating means into the particle settling chamber.
Claim 3
Dependent Claim
59 words
An improvement in copying machines utilizing particulate toner as set forth in claim 1 including in addition a filter assembly having an outlet, an inlet connected to the gas outlet of said separating means, and gas permeable filter means positioned therein so that pneumatic flow from said assembly inlet to said assembly outlet passes through said permeable filter means.
Claim 4
Dependent Claim
36 words
An improvement in copying machines utilizing particulate toner as set forth in claim 1 wherein the particle settling chamber includes means for slowing the pneumatic flow therethrough so that entrained toner particles are separated by gravity.