Thermoforming Web Accumulator and Method

Abstract

A thermoforming web accumulator is provided having a frame, a web guide element, an arm, and an actuator. The frame is configured to be provided within a thermoforming line. The web guide element is configured to be provided beneath a web of thermoformable material being delivered along the thermoforming line. The arm is carried by the frame and is configured to articulate the web guide element between raised and lowered positions. The actuator is operatively coupled with the arm to articulate the arm to controllably move the web guide element between raised and lowered positions to accumulate an extra length of web and discharge the extra length of web during a web splicing operation. A method is also provided.

1 . A thermoforming web accumulator, comprising:
 a frame configured to be provided within a thermoforming line;   a web guide element configured to be provided beneath a web of thermoformable material being delivered along the thermoforming line;   an arm carried by the frame and configured to articulate the web guide element between raised and lowered positions; and   an actuator operatively coupled with the arm to articulate the arm to controllably move the web guide element between raised and lowered positions to accumulate an extra length of web and discharge the extra length of web during a web splicing operation.   
     
     
         2 . The web accumulator of  claim 1 , further comprising a control system operatively coupled with the actuator and adapted to control operation of the arm to raise the web guide element in order to accumulate the extra length of web material and to lower the web guide element in order to supply the accumulated extra length of web to a downstream thermoforming machine during a splicing operation of the thermoforming line. 
     
     
         3 . The web accumulator of  claim 2 , wherein the frame comprises a splicer frame, and further comprising a web splicing apparatus operative to splice together a leading edge of a new web onto a trailing edge of an old web so as to not interrupt feeding of a thermoformable web into a continuously operating thermoforming line. 
     
     
         4 . The web accumulator of  claim 2 , wherein the web guide element comprises a roller configured to support an extra length of web of thermoformable material during accumulating and delivery of the extra length of web material during a web splicing operation. 
     
     
         5 . The web accumulator of  claim 1 , wherein the arm comprises a pair of support arms pivotally supported by the frame in spaced apart relation. 
     
     
         6 . The web accumulator of  claim 5 , wherein the roller comprises a cylindrical roller having a central bore, a pair of bearings one provided at each end about the bore, and a central support shaft extending through the bore, supporting the bearings and affixed at each end to a respective one of the pair of support arms. 
     
     
         7 . The web accumulator of  claim 1 , wherein the frame comprises a pair of spaced-apart support arms, and the arm comprises a pair of curved lift arms each pivotally supported by a respective one of the pair of support arms. 
     
     
         8 . The web accumulator of  claim 1 , wherein the actuator comprises a pneumatic cylinder extending between the arm and the frame and operative to raise and lower the web guide element by extending and retracting the pneumatic cylinder. 
     
     
         9 . The web accumulator of  claim 1 , wherein the web guide element comprises a lateral element extending from the arm and configured to support and guide the web of thermoformable material during delivery of the web through a splicing operation of a continuously operating thermoforming line, while preventing the web from collecting onto a floor. 
     
     
         10 . A thermoforming web accumulator for a web splicing operation, comprising:
 a frame;   a web support element carried for movement relative to the frame; and   a kinematic linkage carried by the frame and configured to support the web support element for articulation between raised and lowered positions corresponding with accumulation and dispersal of an extra length of web prior to and during a web splicing operation.   
     
     
         11 . The thermoforming web accumulator of  claim 10 , wherein the frame is a web splicer frame. 
     
     
         12 . The thermoforming web accumulator of  claim 10 , wherein the web support element comprises a cylindrical roller supported laterally and beneath the web of thermoformable material. 
     
     
         13 . The thermoforming web accumulator of  claim 10 , wherein the kinematic linkage comprises a pair of arms carried for pivotal movement relative to the frame, the web support element carried between the arms spaced from the frame. 
     
     
         14 . The thermoforming web accumulator of  claim 13 , further comprising a drive mechanism coupled between the frame and at least one of the arms operative to articulate the arms to raise and lower the web support element. 
     
     
         15 . The thermoforming web accumulator of  claim 14 , wherein the web support element comprises a cylindrical roller extending laterally between the arms and configured for rotation therebetween. 
     
     
         16 . A method for accumulating a surplus length of thermoformable web material usable during a web splicing operation, comprising:
 providing a web splicer within a thermoforming line and a web accumulator downstream of the web splicer having a web guide element configured to support a thermoformable web and movable between raised and lowered positions;   determining a minimum length of surplus web needed by a thermoforming line;   detecting an end condition for an old web being supplied to the thermoforming line;   raising the web guide element to accumulate at least the minimum length of surplus web usable during a next web splice operation; and   lowering the web guide element to disperse the accumulated length of surplus web while splicing the old web to a new web.   
     
     
         17 . The method of  claim 16 , wherein the web guide element comprises a cylindrical roller extending beneath and transverse to the web and configured to rotate during delivery of the web over the cylindrical roller. 
     
     
         18 . The method of  claim 17 , further comprising advancing the web over the cylindrical roller to advance the web during a thermoforming operation. 
     
     
         19 . The method of  claim 18 , wherein advancing the web occurs concurrent with raising the cylindrical roller. 
     
     
         20 . The method of  claim 18 , wherein advancing the web occurs concurrent with lowering the cylindrical roller. 
     
     
         21 . The method of  claim 16 , wherein determining a minimum length of web comprises determining cycle time and shot length for a thermoforming machine downstream of the splicer, and providing a splice cycle time. 
     
     
         22 . The method of  claim 16 , wherein the old web is provided on a roll, and detecting an end condition for an old web comprises detecting when a diameter of the old web roll falls below a specified size.