Systems and methods for feeding single sheets

Abstract

A sheet feeder for feeding a single sheet of sheet material is disclosed. The sheet feeder can utilize a specially designed cutout and a suction cup to feed difficult, thin, or flimsy material one sheet at the time. The cutout can be located on a shuttle table, endless belt, or carousel, for example, and can be used in conjunction with one or more suctions cups. The cutout can be angled with respect to the sheet so that the leading edge of the sheet is substantially supported. A slot in the cutout can enable the suction cup to pull down the corner of the sheet. The slot can then continue to slice, or peel, the sheet of the bottom of a stack of sheets. The ability to pull only the corner of the sheet down initially prevents stiction from a variety of sources and enables a single sheet to be pulled from the stack.

1 . A machine for feeding single sheets of material comprising:
 a first product tray for holding a plurality of sheets of material in a first stack;   a first angled slot comprising a special cutout located at a first end of the slot;   a first suction cup for reciprocating proximate the special cutout for pulling a single sheet from the bottom of the first stack through the special cutout; and   a device for creating relative motion between the first stack and the first angled slot;   wherein the relative motion between the first angled slot and the first stack removes a single sheet of material from the bottom of the first stack.   
     
     
         2 . The machine of  claim 1 , wherein the device is a reciprocating shuttle table. 
     
     
         3 . The machine of  claim 1 , wherein the device is a rotating belt comprising a plurality of angled slots. 
     
     
         4 . The machine of  claim 1 , wherein the device is a rotating carousel comprising a plurality of angled slots. 
     
     
         5 . The machine of  claim 1 , wherein the special cutout is triangular. 
     
     
         6 . The machine of  claim 1 , further comprising:
 a first spring-loaded pinch roller disposed on the underside of the device; and   a transport belt for pulling the single sheet off the bottom of the first stack;   wherein, when the suction cup pulls the single sheet through the special cutout, the single sheet becomes trapped between the first spring-loaded pinch roller and the transport belt and is removed from the bottom of the first stack.   
     
     
         7 . A machine for feeding single sheets of material comprising:
 a chassis;   a product tray for holding a plurality of sheets of material in a stack;   a shuttle table comprising:
 an angled slot comprising a special cutout; 
 one or more rollers for supporting the shuttle table in rolling engagement with the chassis; and 
 a spring-loaded pinch roller disposed on the underside of the shuttle table; 
   a suction cup, reciprocating proximate the special cutout, for pulling a single sheet from the bottom of the stack through the special cutout; and   a transport belt for pulling the single sheet off the bottom of the stack;   wherein when the suction cup pulls the single sheet through the special cutout, the single sheet becomes trapped between the spring-loaded pinch roller and the transport belt and is removed from the bottom of the stack.   
     
     
         8 . The machine of  claim 7 , wherein the special cutout is triangular. 
     
     
         9 . The machine of  claim 7 , wherein the first angled slot comprises an angled parallelogram and the special cutout comprises a triangle disposed on a first end of the parallelogram. 
     
     
         10 . The machine of  claim 7 , wherein the shuttle table reciprocates with respect to the chassis to pull a single sheet off of the bottom of the stack. 
     
     
         11 . The machine of  claim 7 , further comprising:
 a suction cup cam comprising a first cam profile; and   a suction cup arm for reciprocating the suction cup in response to the first cam profile.   
     
     
         12 . A machine for feeding multiple, single sheets of material comprising:
 a chassis;   a carousel comprising:
 a plurality of angled slots, each angled slots comprising a special cutout; 
 a plurality of spring-loaded pinch rollers disposed on the underside of the carousel; 
   one or more product trays, each tray for holding a plurality of sheets of material in one or more stacks; and   a plurality of suction cups reciprocating proximate each of the special cutouts, each suction cup for pulling a single sheet from the bottom of the one or more stacks through the a plurality of special cutouts;   wherein, when each of the plurality of suction cups pulls a single sheet through one of the a plurality of special cutouts, the single sheet becomes trapped between a spring-loaded pinch roller and the carousel and is dropped below the carousel.   
     
     
         13 . The machine of  claim 12 , wherein the transport belt comprises a rotating flight chain rotating in the opposite direction as the carousel. 
     
     
         14 . The machine of  claim 12 , wherein each of the single sheets are dropped below the carousel onto a transport belt. 
     
     
         15 . The machine of  claim 14 , wherein the transport belt comprises a rotating flight chain rotating in the same direction as the carousel. 
     
     
         16 . The machine of  claim 14 , further comprising:
 a first product tray for holding a plurality of sheets of a first material in a first stack; and   a second product tray for holding a plurality of sheets of a second material in a second stack;   wherein the first material and the second material are collated as they are dropped below the carousel.   
     
     
         17 . A machine for feeding multiple, single sheets of material comprising:
 a chassis;   a rotating belt comprising a plurality of angled slots, each angled slots comprising a special cutout;   one or more product trays, each tray for holding a plurality of sheets of material in one or more stacks, and disposed proximate a top surface of the rotating belt; and   a plurality of suction cups reciprocating proximate each of the special cutouts, each suction cup for pulling a single sheet from the bottom of the one or more stacks through the a plurality of special cutouts;   wherein, when each of the plurality of suction cups pulls a single sheet through one of the a plurality of special cutouts, the belt removes a single sheet from the bottom of the one or more stacks to be dropped below the belt.   
     
     
         18 . The machine of  claim 17 , further comprising:
 a lugged collating base dispose proximate a bottom surface of the rotating belt and comprising a plurality of lugs for collating the plurality of sheets.   
     
     
         19 . The machine of  claim 17 , further comprising:
 a motor; and   a plurality of pulleys in mechanical engagement with the rotating belt;   wherein at least one of the plurality of pulleys is detachably coupled to the motor to rotate the rotating belt.   
     
     
         20 . The machine of  claim 17 , further comprising:
 a reciprocating linkage mechanically coupling the plurality of suction cups for timing the reciprocal motion of the plurality of suction cups.