Adjustable tangent assembly for a diaphragm gas meter

A tangent assembly for a positive displacement diaphragm gas meter to drivingly couple a flag assembly to a crank shaft, comprising:

• a lock plate non-rotatably connected to said crank shaft along the axis of rotation thereof;
• a timing plate;
• a stroke plate pivotally connected to said timing plate;
• means for pivotally connecting one of said timing and stroke plates to said lock plate;
• a first connecting mechanism connected between said lock plate and said one of said timing and stroke plates, said first connecting mechanism being adjustable and adapted to vary the distance between its connection point on said lock plate and said one of said timing and stroke plates so as to pivot said one of said timing and stroke plates with respect to said lock plate;
• a second connecting mechanism connected between said stroke plate and said timing plate, said second connecting mechanism being adjustable and adapted to vary the distance between its connection points on said stroke plate and said timing plate so as to pivot said stroke plate with respect to said timing plate;
• first adjusting means mounted on said lock plate and coupled to said first connecting mechanism for effecting adjustments to said first connecting mechanism;
• second adjusting means mounted on said lock plate and coupled to said second connecting mechanism for effecting adjustments to said second connecting mechanism;
• a wrist pin connected to said stroke plate and extending outwardly therefrom parallel to said crank shaft axis of rotation;
• and
• means for connecting said flag assembly to said wrist pin.