Patent ID: 8219012
Filing Date: 2012-07-10
Classification: G03G,Y10T

Abstract:
1. A toner image transfer apparatus in a printer comprising: transfer belt structure comprising a driven toner image transfer belt and a rotatable backup roll engaging an inner surface of said transfer belt; a rotatable transfer roll adapted to define a nip with said belt and backup roll; and a transfer roll retraction mechanism comprising motion transfer structure coupled to said transfer roll and drive apparatus associated with said motion transfer structure and including a drive motor shared with another structure in the printer separate from said motion transfer structure of said transfer roll retraction mechanism, said motion transfer structure applying a sufficient force to said transfer roll to achieve a desired nip load in response to said drive motor rotating in a first direction and said motion transfer structure decreasing said force to said transfer roll to decrease the load at said nip in response to said drive motor rotating in a second direction, wherein said motion transfer structure applying and decreasing said force without the use of a sensor feedback loop; wherein said drive apparatus further comprises a gear train associated with said drive motor; wherein said motion transfer structure comprises: wherein said first assembly comprises a mounting plate and a gear assembly mounted to said mounting plate, said gear assembly engaging with a gear forming part of said drive apparatus gear train, said mounting plate pivoting in response to movement of said gear assembly, and said first assembly pivoting about an axis of a gear in said gear assembly; wherein said transfer belt structure further comprises a catch associated with said backup roll for rotating with said backup roll and restraining said mounting plate when moved to a locking position in response to said backup roll rotating in a forward direction, said backup roll rotating in a forward direction in response to said transfer belt moving in a forward direction.