Notch-finding mechanism and method of using the same

Abstract

One embodiment of the invention is a notch finding mechanism that at least partially supports and drives a core carrying printer media. The notch finding mechanism includes a notch finding spring and a plurality of support posts that extend from a support disk. The notch finding spring includes a plurality of fingers constructed of a flexible sheet material, and the fingers are positioned circumferentially and adjacent each other to define a plurality of spaces between the fingers. In addition, the fingers are biased radially outwardly, and each of the fingers has a free end that has a width that is approximately matched to a width of a notch in an end of the core. The bias of one of the fingers urges the free end of the finger into the notch aligned with the finger when the core is placed over the fingers and is rotated a small amount.

1 . A notch finding mechanism for at least partially supporting and driving a core of a printer media supply, said core defining at least one notch at an end of the core, the notch finding mechanism comprising: 
 a drive shaft; and    a notch finding spring driven by the drive shaft, said notch finding spring comprising: 
 a plurality of fingers positioned circumferentially about a central axis and adjacent to each other;  
 each of said fingers being biased in a radially outward direction;  
 each of said fingers having a free end;  
   wherein the bias of one of the fingers urges the free end of said finger into the notch defined in the end of the core when the core is placed over the plurality of fingers and rotated.    
     
     
         2 . A notch finding mechanism of  claim 1 , wherein each of the plurality of fingers is constructed of a flexible sheet material.  
     
     
         3 . A notch finding mechanism of  claim 2 , wherein the fingers define a plurality of spaces therebetween.  
     
     
         4 . A notch finding mechanism of  claim 3 , wherein said free end of each of the fingers has a width approximately matched to a width of the notch defined at the end of the supply core.  
     
     
         5 . A notch finding mechanism of  claim 4 , further comprising a support disk supporting the plurality of fingers.  
     
     
         6 . A notch finding mechanism of  claim 5 , further comprising a plurality of support posts extending in the axial direction from a surface of the support disk, each of said plurality of support posts extending into a respective one of said plurality of spaces defined between said fingers.  
     
     
         7 . A notch finding mechanism of  claim 6 , further comprising a frictional clutch positioned between the support disk and a drive disk connected to the drive shaft.  
     
     
         8 . A method of supporting and driving a core of a printer media supply, the method comprising: 
 positioning the core over a notch finding spring having a plurality of fingers with a radially outward bias; and    rotating the core and the notch finding spring relative to each other a small amount until one of the fingers biases into a notch defined in the core.    
     
     
         9 . A method of  claim 8 , wherein the small amount is 30° or less.  
     
     
         10 . A notch finding spring for driving a core, said core defining at least one notch adjacent to an end of the core, the notch finding spring comprising: 
 a plurality of fingers;    said fingers positioned circumferentially about a central axis and adjacent to each other;    each of said fingers being biased in a radial direction;    each of said fingers having a free end, said free end comprising an engaging portion;    wherein the bias of one of the fingers urges the engaging portion into the notch when the core is placed adjacent to the plurality of fingers and rotated.    
     
     
         11 . A notch finding spring of  claim 10  wherein the fingers are biased in a radially inward direction.  
     
     
         12 . A notch finding spring of  claim 10  wherein the engaging portion is at an end of the free end of each finger.  
     
     
         13 . A notch finding spring of  claim 10  wherein the engaging portion is adjacent an end of the free end of each finger.  
     
     
         14 . A notch finding spring of  claim 10  wherein the engaging portion is a protrusion extending in a radial direction from each finger, said protrusion adapted for engaging the notch in the core.  
     
     
         15 . A notch finding spring of  claim 10  wherein the engaging portion comprises a first arcuate shape having a first diameter and the notch comprises a second arcuate shape having a second diameter, the first diameter being slightly smaller than the second diameter, and wherein the engaging portion is adapted to disengage the notch when a torque at the engaging portion exceeds a predetermined amount.  
     
     
         16 . A notch finding spring of  claim 10  wherein the fingers are biased in a radially outward direction.  
     
     
         17 . A notch finding spring of  claim 16 , wherein each of the plurality of fingers is constructed of a flexible sheet material.  
     
     
         18 . A notch finding spring of  claim 17 , wherein each of the plurality of fingers extends from a fixed end in a first axial direction.  
     
     
         19 . A notch finding spring of  claim 18 , wherein each of said fingers has an arcuate-shaped profile, said arcuate-shaped profile defined by each of said fingers extending in the first direction from the fixed end and bending in a radially outward direction through an arc portion to extend in a second axial direction generally opposite the first axial direction and toward said free end.  
     
     
         20 . A notch finding spring of  claim 19 , wherein the fingers define a plurality of spaces therebetween.  
     
     
         21 . A notch finding spring of  claim 20 , wherein said free end of each of the fingers has a width approximately matched to a width of the notch defined at the end of the supply core.  
     
     
         22 . A notch finding spring of  claim 21 , wherein a first diameter around the free ends of the plurality of fingers is greater than an inside diameter of the supply core and a second diameter around the arc portions of the plurality of fingers is less than the inside diameter of the supply core.  
     
     
         23 . A notch finding spring of  claim 22 , wherein each of said fingers includes a middle portion between said arc portion and said free end, said middle portion having a width greater than a width of said free end.  
     
     
         24 . A notch finding spring of  claim 23 , wherein said arc portion of each of said fingers has a reduced cross section.  
     
     
         25 . A notch finding spring of  claim 24 , wherein said plurality of spaces at locations between the arc portions are adapted for aligning with and receiving a plurality of rigid support posts.  
     
     
         26 . A notch finding spring for driving a core, said notch finding spring being secured to the core, the notch finding spring comprising: 
 a plurality of fingers;    said fingers positioned circumferentially about a central axis and adjacent to each other;    each of said fingers being biased in a radial direction;    each of said fingers having a free end, said free end comprising an engaging portion;    wherein the bias of one of the fingers urges the engaging portion into a notch defined adjacent to an end of a drive shaft when the drive shaft is placed adjacent to the plurality of fingers and relatively rotated a small amount.