FOREST UTILIZATION 77 



spector at the same time, so as to turn out the 

 maximum value of edged product. 



(d) The boards are taken to the edger from the live 



rolls onto which the board drops from the log, 

 either by hand or automatically, by chain con- 

 veyors. 



(e) The boards are conveyed from the edger to the 



trimmer by hand. 



E. The trimmer. 



In large mills, trimming follows edging. In small mills, edging 

 follows trimming. 

 I. Parts of the trimmer are : 



(a) One or several circular saws about 18 inches in 



diameter. A one saw trimmer is called a "cut- 

 off." 



(b) Feed works, viz. : live rolls or carriage or barbed 



chains running over sprocket wheels. 



(c) Table. 



II. Task of the trimmer is : 



(a) The shortening of boards to standard lengths of 



6, 8, 10, 12 and up to 20 feet, allowing 2 inches 

 extra for shrinkage. 



(b) The removal of defects at either end, so as to 



ra4se a board into a higher grade. 



(c) The cutting of straight ends. 

 III. Pointers. 



(a) Where two saws are used, the distance between 



them is changed by a lever or by a screw wheel, 

 shifting one of the saws, while it is in motion, 

 along the shaft. 



(b) Chain power fed trimmers are used in all large 



mills. The saws are either jump saws, easily 

 pushed from below the table in pairs, or swing 

 saws, hanging above the table and, similarly, 

 pressed down by the attendant in pairs by a 

 touch on hand or foot levers. 



F. Yard work. (Sorting and piling.) 



I. Sorting. 



The board after leaving the trimmer is taken up by a chain 

 - or cable conveyor and passes by the lumber inspector, 



who pencil-marks its quality. 



The various qualities are either at once thrown inj.o parallel 

 gutter conveyors, leading to separate chutes, below which 

 a wagon or truck is in waiting, or are transferred 

 to the piles by endless chain conveyors, by hand trucks 

 and wagons. Frequently elevated roads traverse the 

 yard on which and below which such conveyance takes 

 place. 



