Patent ID: 6904691

Claim:
A portable coordinate measurement machine (CMM) for measuring the position of an object in a selected volume, comprising: a manually positionable articulated arm having opposed first and second ends, said arm including a plurality of jointed arm segments, each arm segment including at least one position transducer for producing a position signal, two of said jointed arm segments having a hinge joint therebetween, said hinge joint being positioned within a housing component of said articulated arm, said housing component constituting a structural component of said arm such that said housing component comprises a load bearing skeletal component of said arm; a spring counter-balance comprising a spring coaxially mounted around said hinge joint and within said housing component, wherein said spring counter-balance is an integral and internally mounted component of said articulated arm; a measurement probe attached to a first end of said articulated arm; an electronic circuit which receives the position signals from the transducers and provides a digital coordinate corresponding to the position of the probe in a selected volume.