Powder feed mechanism employing vibrating screen

Claim 1

IN AN ELECTROSTATIC PRINTING SYSTEM HAVING A SOURCE OF ELECTROSCOPIC POWDER PARTICLES, A POWDER IMAGE FORMING MEMBER, AN IMAGE RECEIVING SUBSTRATE MEANS FOR ESTABLISHING AN ELECTRIC FIELD BETWEEN SAID POWDER IMAGE FORMING MEMBER AND SAID IMAGE RECEIVING SUBSTRATE, AND MEANS FOR APPLYING POWDER PARTICLES FROM SAID SOURCE TO SAID POWDER IMAGE FORMING MEMBER TO BE CARRIED IN THE SHAPE OF SAID IMAGE TO SAID RECEIVING SUBSTRATE, THE IMPROVEMENT IN APPARATUS FOR FEEDING POWDER TO SAID POWDER IMAGE FORMING MEMBER COMPRISING A POWDER LOADING SCREEN PLACED ADJACENT TO THE SIDE OF SAID POWDER IMAGE FORMING MEMBER TO WHICH POWDER PARTICLES ARE APPLIED TO BE URGED THERETHROUGH, SAID POWDER LOADING SCREEN COMPRISING A PLURALITY OF ELONGATED RESILIENT MEMBERS, MEANS FOR SUPPORTING SAID PLURALITY OF ELONGATED RESILIENT MEMBERS SOLELY BY THEIR ENDS TO BE SUBSTATIALLY PARALLEL WITH ONE ANOTHER AND TO BE INDIVIDUALLY VIBRATABLE, MEANS FOR APPLYING POWDER FROM SAID SOURCE TO SAID POWDER LOADING SCREEN, AND MEANS FOR APPLYING VIBRATING THEM WHILE THEIR PLURALITY OF ELONGATED RESILIENT MEMBERS OF SAID POWDER LOADING SCREEN FOR INDIVIDUALLY VIBRATING THEM WHILE THEIR ENDS REMAIN SUBSTANTIALLY STATIONARY FOR URGING POWDER PARTICLES THROUGH SAID POWER LOADING SCREEN AND THROUGH SAID POWDER IMAGE FORMING MEMBER.