Core driving method for printer web medium supply

Abstract

Methods for operating a printer web medium supply are provided in one aspect of the method. An input force is received and the input force is distributed to supply first force at a first end of a core having a web wound thereon and to supply a second force at a second end of the core with the first force and the second force being sufficient to control rotation the core against an inertial load of the core and web medium wound thereon. Both the first force and the second force are less than a third force applied to a single driven end of an alternative core to rotate the alternative core against the inertial load and wherein the core has a first yield strength at the first end and a second yield strength at the second end that are less than a third yield strength required to receive the third force at the driven end of the alternative core.

1 . A method for operating a printer web medium supply, the method comprising;
 receiving an input force and distributing the input force to supply first force at a first end of a core having a web wound thereon and to supply a second force at a second end of the core with the first force and the second force being sufficient to control rotation of the core against an inertial load of the core and web medium wound thereon;   wherein both the first force and the second force are less than a third force applied to a single driven end of an alternative core to rotate the alternative core against the inertial load and wherein the core has a first yield strength at the first end and a second yield strength at the second end that are less than a third yield strength required to receive the third force at the driven end of the alternative core.   
     
     
         2 . The method of  claim 1 , wherein the volume of the core providing the first yield strength and the second yield strength is less than the volume of the alternative core providing the third yield strength so that more volume is available the printer for the web wound on the core than would be available if the alternative core is used. 
     
     
         3 . The method of  claim 1 , wherein a radius of the core having the first yield strength and the second yield strength is less than a radius of the alternative core providing the third yield strength at the driven end, so that a volume of the web supplied by the core creates less angular momentum than the same volume of web would create if supplied by the alternative core. 
     
     
         4 . The method of  claim 1 , wherein a radius of the core providing the first yield strength and the second yield strength is less than a radius of the alternative core providing the third yield strength, so that the volume of a printer in which the core operates can be made smaller than the volume of a printer in which the alternative core operates while still supplying a common volume of web. 
     
     
         5 . The method of  claim 1 , wherein the volume of the shaft of a core having the first yield strength and second yield strength can be made smaller than the volume of a shaft of an alternative core having the third yield strength while using the same material for fabrication of the core and for fabrication of the alternative core. 
     
     
         6 . The method of  claim 1 , wherein the core can be made from a first material that provides the first yield strength at a first end and second yield strength in a determined configuration, but must be made using a second material that is more dense than the first material to provide the third yield strength to make the alternative core in the determined configuration. 
     
     
         7 . The method of  claim 1 , wherein the core can be made from a first material that provides the first yield strength and second yield strength in a determined configuration, but must be made using a second material that is more rigid than the first material to provide the third yield strength to make the alternative core in the determined configuration. 
     
     
         8 . The method of  claim 1 , wherein the first force and the second force are applied to cause the first end of the core and the second end of the core to remain within a range of rotational positions relative to each other with the range being defined so that the differences in the rotational positions of the first end and the second end create a determined range of shear stress in the core. 
     
     
         9 . The method of  claim 1 , further comprising the step of conveying one of the first force and the second force from a side of the housing confronting one of the first end and the second end to another side of the housing confronting the other of the first end and the second end to drive the other of the first end and the second end without using the core to conveyor the force. 
     
     
         10 . The method of  claim 1 , further comprising the steps of receiving an input force, distributing the input force as the first force and the second force, and conveying the second force along a path to the second end of the core along a path apart from the core. 
     
     
         11 . The method of  claim 1 , wherein the core has an passageway from the first end of the core to the second end of the core and where the method further comprises the steps of mounting a first end of the core to a first core mounting and a second end of the core to a second core mounting and mechanically linking the first core mounting to the second core mounting within the passage of the core such that a portion of an input force can be transferred from a first end of the core to a second end of the core through the mechanical linkage of the first core mounting and the second core mounting. 
     
     
         12 . The method of  claim 1 , wherein the step of distributing the input force comprises distributing the input force as a first force and second force that cause a difference in the rotational positions of the first end and the second end of the core to create a first portion of the shear stress in the core wherein the inertial load induces a second portion of the shear stress in the core, and wherein the first force and the second force are applied so that the first portion is less than half of the total shear stress induced in the core during rotation. 
     
     
         13 . The method of  claim 1 , wherein the first force and the second force are applied to cause the first end and the second end to maintain a determined average rotational relationship over the course of each rotation of the core. 
     
     
         14 . The method of  claim 1 , wherein the first force and the second force are applied to cause the first end and the second end to maintain a determined average rate of rotation over the course of each rotation of the core. 
     
     
         15 . The method of  claim 1 , further comprising the steps of sensing a rotational position of the first end, sensing a rotational position of the second end, and adapting the first force and the second force to control the extent to which the first end and the second end have different rotational positions. 
     
     
         16 . The method of  claim 1 , wherein inertial load experienced by the core is greater at one of the first end and the second end than at the other of the first end and the second end so that a first component of the inertial load experienced at the first end of the core is at a first level and so that a second component the drag experienced at the second end during rotation is at a second different level, and wherein the first force and the second force are in proportion to the component of the inertial load experienced at the first end and the second end. 
     
     
         17 . The method of  claim 1 , wherein the core has a first end that has a first engaged surface that is at a first engaged angle relative to an axis of rotation wherein the first core mounting is one of a plurality of first core mountings each having different engagement surfaces at a plurality of different first engagement angles and wherein the first core mounting has a first detectable feature that differentiates the first core mounting among the plurality of available core mountings and wherein a plurality of different webs can be used in printer web medium supply and wherein data regarding at least one of the plurality of different webs is associated with the engaged angle of the first core mounting and further comprising the step of sensing the first core mounting that can be mounted to a core to allow a core to rotated about the axis of rotation is indicative of the data and sensing first the detectable feature and determining data regarding the web based upon a detected first detectable feature of the first core mounting. 
     
     
         18 . The method of  claim 1 , wherein the printer can be used with a plurality of cores each core having different angular relationships between rotational position the a first cylindric section at a first end of the core and the rotational position of a second cylindric section at a second end of the core such that the rotational separation between the first cylindric section and the second cylindric section are indicative of a characteristic of a web medium wound on the core and further comprising the steps of sensing the rotational position of the first cylindric section, the rotational position of the second cylindric section and determining a data regarding the web wound on the core based upon the rotational separation between the first cylindric section and the second cylindric section. 
     
     
         19 . The method of  claim 18 , wherein step of detecting the rotational position of the first cylindric section and the second cylindric section comprises detecting a rotational position of a first core mounting having a first engagement surface that corresponds to the first cylindric section and mounted to the first end and a second core mounting having a second engagement surface that corresponds to the second cylindric section and mounted to a second end. 
     
     
         20 . A method for controlling rotation of a core in a web medium supply, the method comprising:
 stiffening the core along a length of the core by applying the first force to the first end of the core and a second force to a second end of the core to induce a tension in the core along a length of the core, further applying the first force and the second force with the first force and the second force being sufficient to rotate the core against an inertial load of the core and the web on the core;   wherein both the first force and the second force are less than a third force applied to a single driven end of an alternative core to rotate the alternative core against the drag and wherein the core has a first yield strength at the first end and a second yield strength at the second end that are less than a third yield strength required to receive the third force at the driven end of the alternative core.   
     
     
         21 . The method of  claim 20 , wherein the stiffening of the core reduces an ability of the core to flex perpendicular to an axis of rotation while rotating against the inertial load to reduce the extent of any additional load caused by any increase in friction that can be experienced by the core when the core is allowed to flex perpendicular to an axis of rotation to an extent that is sufficient to bring at least one of the core and the web on the core into contact with the web medium supply. 
     
     
         22 . The method of  claim 20 , wherein at least a portion of the stiffening reduces the extent of any curvature in the core along the axis of rotation. 
     
     
         23 . The method of  claim 20 , wherein the stiffness is adjusted as a function of an anticipated inertial load.