THE WORLD'S ADVANCE 



83 



A SERVICEABLE SECTION LINER 



By C. H. Patterson 



A section liner with which cross lines 

 may be drawn with absolute accuracy is 

 shown in the accompanying drawing. By 

 means of a rachet, the consecutive lines 

 will be drawn exactly the same distance 

 apart. This distance may be varied 

 easily. 



The base of the section-liner consists 

 of a strip of hard wood, B, which is 

 pinned to the drawing board so that an 

 angle may be obtained. The straight 

 edge, D, is secured at its lower end to a 

 45-degree triangle, A, by means of brass 

 plates, E. The triangle, in turn, is nailed 

 to an upright strip of wood, C, to which 

 the spacing mechanism is attached. At 

 the lower end of this strip, a spring, V , 

 is attached which provides rigidity in the 

 straight edge, as well as smooth working 

 qualities. The spring is held in place 

 by a brass cap, T. A threaded wooden 

 block, R, is nailed or glued to the upright 

 strip and countersunk to accommodate a 

 square nut, R, which is held securely in 



place by metal strips, Q. At right an- 

 gles to the upright strip and through the 

 block R a threaded metal rod, tapered at 

 the ends, is passed. At one end of this 

 rod, the rachet is placed. This consists 

 of a metal plate, Y, soldered to the ends 

 of brass blocks, HO, which are nailed 

 to the base, B; and a spring, S, which 



exerts a downward pull on the arm, P; 

 the arm P, sharpened at the outer edge 

 drops into the wedges of a brass adjust- 

 ing knob W '. The threaded rachet rod 

 turns in a bearing consisting of an iron 



