Apparatus and method for singulating porous fuel cell layers using adhesive tape pick head

Abstract

An apparatus and method provide for singulating thin and substantially porous material layers arranged in a stack. A pick head is positioned above the stack of material layers. An adhesive tape is stabilized against the pick head through use of a vacuum between the adhesive tape and the pick head. Contact is effected between the stabilized adhesive tape and the top material layer. The pick head is moved to move the top material layer from the stack to a predetermined location. While at the predetermined location, the adhesive tape is detached from the top material layer. The singulation apparatus and method are particularly well suited for destacking individual porous fluid transport layers (FTLs) from a magazine of FTLs during automated fuel cell assembly.

What is claimed is:  
     
         1 . A method of singulating a plurality of porous fuel cell fluid transport layers (FTLs) arranged in a stack (FTL stack), the FTL stack comprising a top FTL, the method comprising: 
 positioning a pick head above the FTL stack;    stabilizing an adhesive tape against the pick head through use of a vacuum between the adhesive tape and the pick head;    effecting contact between the stabilized adhesive tape and the top FTL;    moving the pick head to move the top FTL from the FTL stack to a predetermined location;    detaching, while at the predetermined location, the adhesive tape from the top FTL; and    repeating the positioning, stabilizing, effecting, moving, and detaching processes for subsequent top FTLs.    
     
     
         2 . The method of  claim 1 , further comprising determining a distance between the pick head and the top FTL, wherein effecting contact further comprises moving the pick head by at least the determined distance such that the adhesive tape contacts the top FTL.  
     
     
         3 . The method of  claim 2 , wherein determining the distance comprises ultrasonically determining the distance between the pick head and the top FTL.  
     
     
         4 . The method of  claim 1 , wherein detaching the adhesive tape comprises extending a stripper mechanism of the pick head to effect detachment of the adhesive tape from the top FTL.  
     
     
         5 . The method of  claim 4 , wherein detaching the adhesive tape further comprises retracting the stripper mechanism after detaching the adhesive tape from the top FTL.  
     
     
         6 . The method of  claim 1 , further comprising advancing the adhesive tape to present unused adhesive proximate the pick head after detaching the adhesive tape from the top FTL.  
     
     
         7 . The method of  claim 6 , further comprising removing the vacuum between the adhesive tape and the pick head after detaching the adhesive tape from the top FTL and prior to advancing the adhesive tape.  
     
     
         8 . The method of  claim 1 , wherein the FTL stack is stationary, and effecting contact comprises moving the pick head so that the adhesive tape contacts the top FTL.  
     
     
         9 . The method of  claim 1 , wherein effecting contact comprises displacing the pick head vertically so that the adhesive tape contacts the top FTL, and moving the pick head comprises moving the pick head horizontally to move the top FTL to the predetermined location.  
     
     
         10 . The method of  claim 1 , further comprising detecting presence or absence of the adhesive tape at the pick head.  
     
     
         11 . The method of  claim 1 , wherein detaching the adhesive tape from the top FTL comprises detaching the adhesive tape from the top FTL at the predetermined location with a positional tolerance ranging between about 0.01 inches and about 0.02 inches.  
     
     
         12 . A method of singulating a plurality of thin and substantially porous material layers arranged in a stack, the stack of material layers comprising a top material layer, the method comprising: 
 positioning a pick head above the stack of material layers;    stabilizing an adhesive tape against the pick head through use of a vacuum between the adhesive tape and the pick head;    effecting contact between the stabilized adhesive tape and the top material layer;    moving the pick head to move the top material layer from the stack to a predetermined location;    detaching, while at the predetermined location, the adhesive tape from the top material layer; and    repeating the positioning, stabilizing, effecting, moving, and detaching processes for subsequent top material layers.    
     
     
         13 . The method of  claim 12 , further comprising determining a distance between the pick head and the top material layer, wherein effecting contact further comprises moving the pick head by at least the determined distance such that the adhesive tape contacts the top material layer.  
     
     
         14 . The method of  claim 12 , wherein determining the distance comprises ultrasonically determining the distance between the pick head and the top material layer.  
     
     
         15 . The method of  claim 12 , wherein detaching the adhesive tape comprises extending a stripper mechanism of the pick head to effect detachment of the adhesive tape from the top material layer.  
     
     
         16 . The method of  claim 15 , wherein detaching the adhesive tape further comprises retracting the stripper mechanism after detaching the adhesive tape from the top material layer.  
     
     
         17 . The method of  claim 12 , further comprising advancing the adhesive tape to present unused adhesive proximate the pick head after detaching the adhesive tape from the top material layer.  
     
     
         18 . The method of  claim 17 , further comprising removing the vacuum between the adhesive tape and the pick head after detaching the adhesive tape from the top material layer and prior to advancing the adhesive tape.  
     
     
         19 . The method of  claim 12 , wherein the stack of material layers is stationary, and effecting contact comprises moving the pick head so that the adhesive tape contacts the top material layer.  
     
     
         20 . The method of  claim 12 , wherein effecting contact comprises displacing the pick head vertically so that the adhesive tape contacts the top material layer, and moving the pick head comprises moving the pick head horizontally to move the top material layer to the predetermined location.  
     
     
         21 . The method of  claim 12 , further comprising detecting presence or absence of the adhesive tape at the pick head.  
     
     
         22 . The method of  claim 12 , wherein detaching the adhesive tape from the top material layer comprises detaching the adhesive tape from the top material layer at the predetermined location with a positional tolerance ranging between about 0.01 inches and about 0.02 inches.  
     
     
         23 . An apparatus for singulating a plurality of porous fuel cell fluid transport layers (FTLs) arranged in a stack (FTL stack), the FTL stack comprising a top FTL, the apparatus comprising: 
 a pick head comprising a pick region, a stripper mechanism situated proximate the pick region, and a vacuum port located at the pick region, the vacuum port adapted for coupling to a vacuum system;    a tape drive mechanism, the tape drive mechanism controlling movement of an adhesive tape proximate the vacuum port at the pick region;    a positioning system that supports the pick head, the positioning system controllable to move the pick head vertically and horizontally; and    a controller, the controller programmed to control the positioning system to move the pick head so that the adhesive tape contacts the top FTL, the adhesive tape stabilized at the pick region by a vacuum between the adhesive tape and the pick region, the controller programmed to further control the positioning system to move the pick head to a predetermined location, the stripper mechanism actuating to detach the top FTL from the adhesive tape at the predetermined location.    
     
     
         24 . The apparatus of  claim 23 , wherein the controller is programmed to effect repeated singulation of FTLs from the FTL stack.  
     
     
         25 . The apparatus of  claim 23 , wherein the tape drive mechanism is connected to the pick head.  
     
     
         26 . The apparatus of  claim 23 , wherein the tape drive mechanism is separate from the pick head.  
     
     
         27 . The apparatus of  claim 23 , wherein the tape drive mechanism comprises a wind-up mechanism and an unwind mechanism, the wind-up and; unwind mechanisms cooperating to move the adhesive tape so that unused adhesive of the adhesive tape is presented at the pick region.  
     
     
         28 . The apparatus of  claim 27 , wherein the wind-up and unwind mechanisms each comprise a roll, and the adhesive tape is unwound from the roll of the unwind mechanism and wound on the roll of the wind-up mechanism.  
     
     
         29 . The apparatus of  claim 27 , wherein the wind-up mechanism comprises a roller clutch needle bearing and a brake, the roller clutch needle bearing and brake cooperating to index the adhesive tape in a forward direction from the unwind mechanism to the wind-up mechanism.  
     
     
         30 . The apparatus of  claim 27 , wherein the pick head comprises a pneumatic cylinder and a linkage, the pneumatic cylinder and linkage cooperating to advance the adhesive tape between the unwind mechanism and the wind-up mechanism.  
     
     
         31 . The apparatus of  claim 23 , wherein the pick head comprises a pneumatic cylinder and a linkage, the pneumatic cylinder and linkage cooperating to actuate the stripper mechanism.  
     
     
         32 . The apparatus of  claim 31 , wherein the controller is programmed to control the pneumatic cylinder so that the stripper mechanism is actuated at the predetermined location to detach the top FTL from the adhesive tape.  
     
     
         33 . The apparatus of  claim 23 , wherein the stripper mechanism comprises stripper feet.  
     
     
         34 . The apparatus of  claim 23 , further comprising a distance sensor at the pick head, the distance sensor determining a distance between the pick head and the top FTL.  
     
     
         35 . The apparatus of  claim 34 , wherein the distance sensor comprises an ultrasonic sensor.  
     
     
         36 . The apparatus of  claim 23 , further comprising a sensor that senses presence or absence of the adhesive tape proximate the pick region.  
     
     
         37 . The apparatus of  claim 23 , wherein the pick head comprises one or more springs mounted to provide counter-balance for weight of the pick head.  
     
     
         38 . The apparatus of  claim 23 , wherein the pick head and tape drive mechanism define a unitary pick head unit, and a plurality of pick head units are supported by the positioning system.  
     
     
         39 . The apparatus of  claim 23 , wherein the positioning system comprises a vertical servomotor for moving the pick head vertically, and a horizontal servomotor for moving the pick head horizontally.  
     
     
         40 . The apparatus of  claim 39 , wherein the pick head comprises vertical linear slides to allow for slight over travel of the vertical servomotor to ensure adequate contact between the adhesive tape and the top FTL.  
     
     
         41 . The apparatus of  claim 39 , wherein the vertical servomotor is coupled to a rack and pinion arrangement, and the horizontal servomotor is coupled to a ball screw assembly.  
     
     
         42 . The apparatus of  claim 23 , wherein the apparatus includes a pair of the pick heads comprising a first pick head and a second pick head, and the tape drive mechanism comprises an unwind mechanism mounted proximate the first pick head and a wind-up mechanism proximate the second pick head, the unwind and wind-up mechanisms cooperating to control movement of the adhesive tape proximate the vacuum port at the pick region of the first and second pick heads, respectively.  
     
     
         43 . The apparatus of  claim 42 , wherein the first and second pick heads define a unitary pick head assembly.  
     
     
         44 . The apparatus of  claim 42 , wherein the first and second pick heads define separate pick head assemblies.  
     
     
         45 . The apparatus of  claim 23 , wherein the positioning system detaches the top FTL from the adhesive tape at the predetermined location with a positional tolerance ranging between about 0.01 inches and about 0.02 inches.  
     
     
         46 . An apparatus for singulating a plurality of porous material layers arranged in a stack, the stack comprising a top porous material layer, the apparatus comprising: 
 a pick head comprising a pick region, a stripper mechanism situated proximate the pick region, and a vacuum port located at the pick region, the vacuum port adapted for coupling to a vacuum system;    a tape drive mechanism, the tape drive mechanism controlling movement of an adhesive tape proximate the vacuum port at the pick region;    a positioning system that supports the pick head, the positioning system controllable to move the pick head vertically and horizontally; and    a controller, the controller programmed to control the positioning system to move the pick head so that the adhesive tape contacts the top porous material layer, the adhesive tape stabilized at the pick region by a vacuum between the adhesive tape and the pick region, the controller programmed to further control the positioning system to move the pick head to a predetermined location, the stripper mechanism actuating to detach the top porous material layer from the adhesive tape at the predetermined location.    
     
     
         47 . The apparatus of  claim 46 , wherein the controller is programmed to effect repeated singulation of the porous material layers from the stack.  
     
     
         48 . The apparatus of  claim 46 , wherein the tape drive mechanism is connected to the pick head.  
     
     
         49 . The apparatus of  claim 46 , wherein the tape drive mechanism is separate from the pick head.  
     
     
         50 . The apparatus of  claim 46 , wherein the tape drive mechanism comprises a wind-up mechanism and an unwind mechanism, the wind-up and unwind mechanisms cooperating to move the adhesive tape so that unused adhesive of the adhesive tape is presented at the pick region.  
     
     
         51 . The apparatus of  claim 46 , wherein the stripper mechanism comprises stripper feet.  
     
     
         52 . The apparatus of  claim 46 , further comprising a distance sensor at the pick head, the distance sensor determining a distance between the pick head and the top porous material layer.  
     
     
         53 . The apparatus of  claim 52 , wherein the distance sensor comprises an ultrasonic sensor.  
     
     
         54 . The apparatus of  claim 46 , further comprising a sensor that senses presence or absence of the adhesive tape proximate the pick region.  
     
     
         55 . The apparatus of  claim 46 , wherein the pick head comprises one or more springs mounted to provide counter-balance for weight of the pick head.  
     
     
         56 . The apparatus of  claim 46 , wherein the pick head and tape drive mechanism define a unitary pick head unit, and a plurality of pick head units are supported by the positioning system.  
     
     
         57 . The apparatus of  claim 46 , wherein the positioning system comprises a vertical servomotor for moving the pick head vertically, and a horizontal servomotor for moving the pick head horizontally.  
     
     
         58 . The apparatus of  claim 57 , wherein the pick head comprises vertical linear slides to allow for slight over travel of the vertical servomotor to ensure adequate contact between the adhesive tape and the top porous material layer.  
     
     
         59 . The apparatus of  claim 57 , wherein the vertical servomotor is coupled to a rack and pinion arrangement, and the horizontal servomotor is coupled to a ball screw assembly.  
     
     
         60 . The apparatus of  claim 46 , wherein the apparatus includes a pair of the pick heads comprising a first pick head and a second pick head, and the tape drive mechanism comprises an unwind mechanism mounted proximate the first pick head and a wind-up mechanism proximate the second pick head, the unwind and wind-up mechanisms cooperating to control movement of the adhesive tape proximate the vacuum port at the pick region of the first and second pick heads, respectively.  
     
     
         61 . The apparatus of  claim 60 , wherein the first and second pick heads define a unitary pick head assembly.  
     
     
         62 . The apparatus of  claim 60 , wherein the first and second pick heads define separate pick head assemblies.  
     
     
         63 . The apparatus of  claim 46 , wherein the positioning system detaches the top porous material layer from the adhesive tape at the predetermined location with a positional tolerance ranging between about 0.01 inches and about 0.02 inches.