THE WOOD WORKING PLANT 



127 



PARAGRAPH XX. 

 THE WOOD WORKING PLANT. 



(A) PLANING (surfacing, dressing, or sizing). The planer consists of cylindrical cutter heads carrying 

 from two to six knives and making 3,000 to 5,000 revolutions per minute. It is belted preferably at both sides. 



The smaller the diameter of the cylinder with its knives, the smoother is the planing. 



The feeding is done either by two to four feed rolls (above) and friction rolls (below), or by a 

 travelling bed. The entire cutting length of the knives should be uniformly used. The top cutter should 

 do the heavier work in double surfacers. 



The "wedge platen" device patented by the S. A. Woods Machine Company, Boston, Massachussetts, 

 allows of relieving or of increasing instantaneously either the f^ upper or else the lower cut of 

 a double surfacer, without 

 altering the final thickness 

 of the finished product. 



The knives are usually 

 sharpened automatically. 



The lumber is fed 

 into the machine, with 

 the grain, at the rate 

 of 20 feet to 150 feet 

 per minute. Hard- 

 woods are fed more 

 slowly than softwoods 



The chip breaker 

 is a front pressure 

 bar preventing long 

 splinters from being 

 torn off. 



Price of single 

 planers is -y 100 to 

 5^400; of double pla- 

 ners .v400 to .v800. 



by eight -inch surface planer, with divided feed 

 ded chip breaker. H. B. Smith Machine Co., 

 Smithville, N. J. 



Endless bed surfacer. Fay & Egan, Cincinnati, Ohio. 



Surfacer No. 206. Fay & Egan, Cincinnati, Ohio. 



