Nip release system

Abstract

Methods and system for reducing sheet skew in a sheet transport system are disclosed. A sheet transport system may include an idler wheel, a drive wheel a drive motor and an actuator. The idler wheel may have a substantially rigid outer layer. The drive wheel may have a compliant outer layer and may correspond to the idler wheel. The drive motor may be operably connected to the drive wheel and may be configured to cause the drive wheel to rotate around a shaft. The actuator may be operably connected to the drive wheel and configured to cause the drive wheel to move between a closed position and an open position. The drive wheel is configured to contact a sheet in the closed position and to not contact a sheet in the open position.

1 . A sheet transport system, comprising:
 a first idler wheel having a substantially rigid outer layer;   a first drive wheel having a compliant outer layer, wherein the first drive wheel corresponds to the first idler wheel;   a drive motor operably connected to the first drive wheel, wherein the drive motor is configured to cause the first drive wheel to rotate around a first shaft; and   a first actuator operably connected to the first drive wheel, wherein the first actuator is configured to cause the first drive wheel to move between a closed position and an open position, wherein the first drive wheel is configured to contact a sheet in the closed position and to not contact a sheet in the open position.   
     
     
         2 . The sheet transport system of  claim 1  wherein the drive motor is downstream from the drive wheel in a process flow direction. 
     
     
         3 . The sheet transport system of  claim 1  wherein the drive motor is upstream from the drive wheel in a process flow direction. 
     
     
         4 . The sheet transport system of  claim 1  wherein the first actuator is integral to the drive motor. 
     
     
         5 . The sheet transport system of  claim 1  wherein the first actuator is further configured to cause at least a portion of the drive motor to rotate when causing the first drive wheel to move between a closed position and an open position. 
     
     
         6 . The sheet transport system of  claim 1  wherein the first actuator is disposed in a fixed location. 
     
     
         7 . The sheet transport system of  claim 1 , further comprising:
 a second idler wheel having a substantially rigid outer layer; and   a second drive wheel having a compliant outer layer, wherein the second drive wheel corresponds to the second idler wheel,   wherein the drive motor is further configured to cause the second drive wheel to rotate,   wherein the first actuator is further configured to cause the second drive wheel to move between a closed position and an open position, wherein the second drive wheel is configured to contact a sheet in the closed position and to not contact a sheet in the open position.   
     
     
         8 . The sheet transport system of  claim 7  wherein the drive motor is further configured to cause the second drive wheel to rotate around the first shaft. 
     
     
         9 . The sheet transport system of  claim 7  wherein the drive motor is further configured to cause the second drive wheel to rotate around a second shaft. 
     
     
         10 . The sheet transport system of  claim 7  wherein the first actuator is further configured to cause the first and second drive wheels to independently move between the closed and open positions. 
     
     
         11 . The sheet transport system of  claim 1 , further comprising:
 a second idler wheel having a substantially rigid outer layer;   a second drive wheel having a compliant outer layer, wherein the second drive wheel corresponds to the second idler wheel; and   a second actuator operably connected to the second drive wheel, wherein the second actuator is configured to cause the second drive wheel to move between a closed position and an open position, wherein the second drive wheel is configured to contact a sheet in the closed position and to not contact a sheet in the open position,   wherein the drive motor is further configured to cause the second drive wheel to rotate.   
     
     
         12 . A sheet transport system, comprising:
 a first idler wheel having a substantially rigid outer layer;   a first drive wheel having a compliant outer layer, wherein the first drive wheel corresponds to the first idler wheel;   a drive motor operably connected to the first drive wheel, wherein the drive motor is configured to cause the first drive wheel to rotate around a first shaft; and   a first actuator operably connected to the first drive wheel and the drive motor, wherein the first actuator is configured to cause the first drive wheel and the drive motor to move between a closed position and an open position, wherein the first drive wheel is configured to contact a sheet in the closed position and to not contact a sheet in the open position.   
     
     
         13 . The sheet transport system of  claim 12  wherein the first actuator is further configured to move the first drive wheel and the drive motor a substantially equal distance when causing the first drive wheel and the drive motor to move between a closed position and an open position. 
     
     
         14 . The sheet transport system of  claim 12  wherein the first actuator is further configured to rotate the first drive wheel and the drive motor when causing the first drive wheel and the drive motor to move between a closed position and an open position. 
     
     
         15 . The sheet transport system of  claim 12 , further comprising:
 a second idler wheel having a substantially rigid outer layer; and   a second drive wheel having a compliant outer layer, wherein the second drive wheel corresponds to the second idler wheel,   wherein the drive motor is further configured to cause the second drive wheel to rotate,   wherein the first actuator is further configured to cause the second drive wheel to move between a closed position and an open position, wherein the second drive wheel is configured to contact a sheet in the closed position and to not contact a sheet in the open position.   
     
     
         16 . The sheet transport system of  claim 15  wherein the drive motor is further configured to cause the second drive wheel to rotate around the first shaft. 
     
     
         17 . The sheet transport system of  claim 15  wherein the drive motor is further configured to cause the second drive wheel to rotate around a third shaft. 
     
     
         18 . The sheet transport system of  claim 15  wherein the first actuator is further configured to cause the first and second drive wheels to independently move between the closed and open positions. 
     
     
         19 . The sheet transport system of  claim 12 , further comprising:
 a second idler wheel having a substantially rigid outer layer;   a second drive wheel having a compliant outer layer, wherein the second drive wheel corresponds to the second idler wheel; and   a second actuator operably connected to the second drive wheel, wherein the second actuator is configured to cause the second drive wheel to move between a closed position and an open position, wherein the second drive wheel is configured to contact a sheet in the closed position and to not contact a sheet in the open position,   wherein the drive motor is further configured to cause the second drive wheel to rotate.   
     
     
         20 . A method of reducing sheet skew in a sheet transport system, the method comprising:
 automatically moving a drive wheel of a nip from an open position to a closed position, wherein the nip comprises an idler wheel and the drive wheel, wherein the idler wheel comprises a substantially rigid outer layer, wherein the drive wheel comprises a substantially compliant outer layer, wherein the drive wheel is configured to not contact a sheet in the open position and is configured to contact a sheet in the closed position;   receiving a sheet at the nip;   using the drive wheel to transport the sheet through the nip; and automatically moving the drive wheel from the closed position to the open position.