The lengths of the links comply with the conditions: A͞B=1, B͞C=C͞E=C͞D=1.4 and A͞E=2.58. Point D of the Chebyshev-type four-bar linkage ABCD has approximate straight-line motion. The mechanism is driven by link 3 which is connected by turning pair F to link 2 and by spherical pair G to link 1. Link 1 is connected by a system of links, not shown in the drawing, to the indicator which measures the pressure in the engine cylinder. The motion of link 1 is transformed into approximately rectilinear motion of the tracer, or pencil, which is at point D of link 2. Paper strip 4 is moved a distance proportional to travel s of the piston in the engine cylinder. At this, the pencil traces the curve p=p(s), where p is a quantity proportional to the steam or gas pressure in the cylinder.
$823$LW,M$