Patent ID: 7942044

Claim:
A reciprocating machine comprising: a crank case; a crankshaft supported for rotation within the crank case; a cylinder defining a bore; a piston reciprocable within the bore of the cylinder, the piston having at least one bearing surface; a wrist pin supported by the at least one bearing surface; a connecting rod having a first end pivotally connected to the crankshaft and a second end pivotally connected to the wrist pin to convert reciprocal movement of the piston into rotation movement of the crankshaft; a rotational element having alternating slits and solid portions and being rotationally coupled to the wrist pin; a first binary signal generator including a first optical signal generator on one side of the rotational element and a first optical signal receiver on an opposite side of the rotational element and aligned with the first optical signal generator, such that the first binary signal generator generates a first binary signal in response to respective slits and solids of the rotational element being positioned between the first optical signal generator and the first optical signal receiver, the first binary signal generator being decoupled from rotational movement with the wrist pin; a second binary signal generator including a second optical signal generator on the one side of the rotational element and a second optical signal receiver on the opposite side of the rotational element and aligned with the second optical signal generator, such that the second binary signal generator generates a second binary signal in response to respective slits and solids of the rotational element being positioned between the second optical signal generator and the second optical signal receiver, the second binary signal generator being decoupled from rotational movement with the wrist pin; and a circuit configured to receive the first and second binary signals and convert the first and second binary signals into a single analog signal, wherein the first and second binary signals provide a first digit and a second digit in a two-digit binary signal that is converted to the single analog signal.