Constant sine bar
FIG. 1 is a top and left rear perspective view of a constant sine bar showing my new design; 
     FIG. 2 is a left side elevational view thereof, the right side being a mirror image thereto. The broken line showing of a roll-pin is environmental only and forms no part of the claimed design; 
     FIG. 3 is a top plan view thereof, 
     FIG. 4 is a bottom plan view thereof, 
     FIG. 5 is a rear elevational view thereof; and 
     FIG. 6 is a front elevational view thereof.