Slip feed roller feeding

Abstract

A method and assembly provide a feed roller that is designed to slip when a foreign object, not designed to be fed by the feed roller, engages the feed roller. One or more rollers are mounted on a shaft and have a grooved surface spring pressed into engagement with a pin extending radially outwardly from the shaft. When a force is applied to the circumference of the roller greater than the force applied by a spring which biases the grooved surface into contact with the pin, the roller will slip, and substantially stop rotating. Since the shaft continues to be driven, if the foreign object is removed the next time the grooved surface is aligned with the pin it will be biased into engagement with the pin so that that roller automatically starts to rotate and provide a feeding action again.

What is claimed is:  
     
         1 . A method of feeding mailing media having a normal thickness of at least about 0.125 inches, comprising: 
 (a) engaging the mailing media having a normal thickness of at least about 0.125 inches with a plurality of drive rollers on a common shaft to move the media in a first direction; and    (b) if one or more of the rollers engage a foreign object, causing the one or more rollers engaging the foreign object to automatically substantially stop rotating while rollers not engaging the foreign object continue to rotate.    
     
     
         2 . A method as recited in    claim 1    further comprising (c) when engagement of the foreign object with the one or more rollers is terminated, automatically causing those one or more rollers to continue rotating, engaging and moving the mailing media.  
     
     
         3 . A method as recited in    claim 2    wherein (a)-(c) are practiced using a shaft having a plurality of pins extending radially outwardly from the shaft, and a grooved surface operatively connected to each roller having the grooved surface thereof engaging one of the pins, and a spring which biases each roller grooved surface into contact with a pin.  
     
     
         4 . A method as recited in    claim 1    wherein (a) is practiced to move the mailing media from a stack in a first direction away from the stack.  
     
     
         5 . A method as recited in    claim 4    wherein (a) is further practiced to engage and move the bottom of the lowest mailing media in the stack.  
     
     
         6 . A method as recited in    claim 2    wherein (a) is practiced to move the mailing media from a stack in a first direction away from the stack.  
     
     
         7 . A method as recited in    claim 6    wherein (a) is further practiced to engage and move the bottom of the lowest mailing media in the stack.  
     
     
         8 . A method of feeding sheet material, comprising: 
 (a) engaging the sheet material with a plurality of drive rollers on a common shaft to move the sheet material in a first direction;    (b) if one or more of the rollers engage a foreign object, causing the one or more rollers engaging the foreign object to automatically substantially stop rotating while rollers not engaging the foreign object continue to rotate; and    (c) when engagement of the foreign object with the one or more rollers is terminated, automatically causing those one or more rollers to continue rotating, engaging and moving the sheet material.    
     
     
         9 . A method as recited in    claim 8    wherein (a)-(c) are practiced using a shaft having a plurality of pins extending radially outwardly from the shaft, and a grooved surface operatively connected to each roller having the grooved surface thereof engaging one of the pins, and a spring which biases each roller grooved surface into contact with a pin.  
     
     
         10 . A method as recited in    claim 8    wherein (a) is practiced to move the sheet material from a stack in a first direction away from the stack.  
     
     
         11 . A method as recited in    claim 10    wherein (a) is further practiced to engage and move the bottom of the lowest sheet of sheet material in the stack.  
     
     
         12 . A media moving assembly comprising: 
 a shaft;    a roller mounted on said shaft;    a pin extending radially outwardly from said shaft;    a grooved surface operatively connected to said roller; and    a spring which biases said roller grooved surface into contact with said pin, so that said pin and grooved surface provide a slip connection between said roller and shaft.    
     
     
         13 . An assembly as recited in    claim 12    wherein said spring comprises a coil spring surrounding said shaft.  
     
     
         14 . An assembly as recited in    claim 12    wherein said pin is substantially circular in cross-section and said groove is substantially V-shaped.  
     
     
         15 . An assembly as recited in    claim 12    wherein said roller comprises a first roller having a first grooved surface operatively connected thereto, and said pin comprises a first pin; and further comprising at least a second roller on said shaft, and a second pin extending radially outwardly from said shaft, a second grooved surface operatively associated with said second roller spring biased into engagement with said second pin.  
     
     
         16 . An assembly as recited in    claim 15    wherein a single coil spring surrounding said shaft extends between said first and second rollers and simultaneously biases said first and second rollers toward engagement with said first and second pins.  
     
     
         17 . An assembly as recited in    claim 16    further comprising first and second washers between said coil spring and said first and second rollers.  
     
     
         18 . An assembly as recited in    claim 16    wherein said spring has a rate of between about 30-32 pounds/inch and an installed force of between about 10-12 pounds, and said rollers have an outside diameter of between about 2.4-2.8 inches.  
     
     
         19 . An assembly as recited in    claim 18    wherein each of said pins is substantially circular in cross-section and each of said grooves is substantially V-shaped, and each of said pins has a portion thereof on each side of said shaft and each of said grooved surfaces has a groove on each side of said shaft, so that two portions of each pin engage two grooves of said grooved surface.  
     
     
         20 . An assembly as recited in    claim 12    wherein said grooved surface is fixed to said roller.  
     
     
         21 . An assembly as recited in    claim 15    further comprising a plurality of additional rollers mounted on said shaft, and a plurality of additional pins, and at least some of said additional plurality of rollers having a grooved surface spring biased into engagement with a pin.  
     
     
         22 . An assembly as recited in    claim 21    wherein said shaft is mounted in a printer; and further comprising means for rotating said shaft so that said rollers on said shaft engage media in a stack to feed the media from the stack into said printer.  
     
     
         23 . An assembly as recited in    claim 12    wherein said roller comprises a hard plastic body roller having a resilient material circumferential covering.  
     
     
         24 . An assembly as recited in    claim 14    wherein said grooved surface is fixed to said roller; and wherein said pin extends through said shaft and has a portion thereof on each side of said shaft and said grooved surface has a groove on each side of said shaft, so that two portions of each pin engage two grooves of said grooved surface.  
     
     
         25 . An assembly as recited in    claim 23    wherein said roller body comprises nylon with between about 20-40% glass bead fill, and said resilient material is Nitrile rubber having a durometer of between about 10-30 Shore A.