US Patent 7200256 Pin protrusion measurement probe

A system for pin protrusion measurement of a fastener includes a pin protrusion measurement probe having an electronic camera and a probe socket. The probe socket fits over a nut of the fastener and establishes a fixed, stable position of the pin protrusion measurement probe relative to the fastener. Light from the fastener passes through a viewing window in the probe socket, is reflected through a right angle prism, focused by a lens, and forms an image of the fastener in the electronic camera. A real-time monitor display allows an operator to view the image. A computer, connected to the electronic camera, and having a vision system, processes the image of the fastener, and provides the pin protrusion measurement.