Patent ID: 8261459

Claim:
A modular edge reference tool comprising: a first segment defining a longitudinal axis and a reference edge and having an extending end; a second segment defining a longitudinal axis and a reference edge and having a receptacle end; a coupling mechanism that couples the extending end and the first segment to the receptacle end of the second segment in a first and second stage that includes: a first component mounted within the extending end of the first segment that includes: a shaft slidably mounted to the extending end of the first segment with extended and retracted positions that includes an external geometry that extends from the extending end in the extended position; a compression spring that is coupled to the shaft with one end that is substantially fixed to the shaft and a second end that moves relative to the shaft; a handle coupled to the second end of the spring with a first position that arranges the second end of the spring to extend the shaft and a second position that arranges the second end of the spring to retract the shaft; a second component mounted within the receptacle end of the second segment that defines a hole, wherein the hole includes an entrance geometry that allows the hole to receive the extended external geometry of the shaft when the second segment is offset along the longitudinal axis from the first segment, wherein the hole includes internal geometry that subsequently engages the external geometry of the shaft and moves the shaft deeper into the hole upon a rotation of the second segment relative to the first segment to substantially hold the shaft in the extended position wherein the first end of the spring moves with the shaft closer to the second end of the spring as the shaft moves deeper into the hole upon the rotation of the second segment to provide a force of a first degree in the first stage to couple the first segment to the second segment; and wherein the transition of the handle from the first position to the second position moves the second end of the spring farther towards the first end of the spring to provide a force of a second degree higher than the first degree in the second stage to couple the first segment to the second segment.