428 



MARINE PRODUCTS OF COMMERCE 



TOO TIGHT 



TOO LOOSE 



NORMAL TOO TIGHT 



(Courtesy U. S. Fish and Wildlife Service) 



Fig. 20-3. Correctly and incorrectly formed can seams. 

 Above, correctly formed first operation seams. Center, seams 

 incorrectly formed by first roll. Bottom, seams formed by 

 second roll. 



CHUCK SPINDLE 



I I 

 I I 

 I I 

 J— L 



SEAMER CHUCK 



FLANGE JUST PASSES 

 OVER EDGE OF CHUCK 



^^' 



IRST ROLL 



FIRST ROLL 



^ 



CHUCK TOO HIGH AND FLANGE 

 RUBS EDGE WEARS CHUCK 

 AND ROLL UNDULY 



n\ 



FLANGE SET TOO HIGH 

 ABOVE EDGE OF CHUCK 

 RESULTS IN CUTOVER SEAMS 



5^ 



FIRST ROLL 



(.Courtesy L. G. McKec) 



Fig. 20—4. Adjustments for the can sealing machine. Above, cor- 

 rectly adjusted first operation roll. Below, Incorrectly adjusted first 

 operation roll (misalignment is exaggerated). 



