1. Field of the Invention
The invention relates to the field of inspection devices and, in particular, to a self centering device that allows a laser measurement device to inspect the countersink in countersunk holes.
2. Description of Related Art
Flush head fasteners require that the fastener holes be countersunk. The inspection of countersink portion of holes is a time consuming operation; particularly if mechanical or optical inspection techniques are used. This is particularly true on large aircraft structures with a tremendous number of such fasteners. While automated drilling equipment greatly reduces the chance of out of tolerance fastener holes, inspection is still required. One of the most common methods is to use a Trulok gage, which consists of a spring loaded ball, which is seated in the countersink. It can determine only the depth of the countersink. It is calibrated assuming a 100 degree countersink. Several different balls are required because of the necessity of seating the balls tangent to the countersink. Finally it can not be used on complex surfaces. What is needed is a simple and automatic measuring device that can be installed in an automated fastener drilling machine or operated by hand.
Lasers are used in numerous inspection and measurement systems. One particularly useful device is a portable gap measurement system; particularly useful in inspecting the gaps between body panels and doors on automobiles. This device is a hand held and passed along the gap and automatically measures and records the gap and determines whether the gap is out of tolerance. The device consists of a laser transmitter, which passes a laser beam back and forth across the gap (forming a visual line across the gap) and an optical light receiver and recorder. The change in time of the received laser light as it passes over the edges of the gap is recorded by a laser line sensor which enables extremely high resolution profile scanning of up to 500 points across a horizontal measuring line of one inch length as well as the change when the laser light beam passes out of the gap. It is a simple calculation to determine the width of the gap and whether it is in tolerance or not. If such a device could be properly positioned over a countersunk hole it could be used determine if it was in tolerance or not.
Thus, it is a primary object of the invention to provide a device that can self center the laser beam to measure the dimensions of a countersink hole.
It is another primary object of the invention to provide a device that can self center the laser beam to measure the dimensions of a countersink that is portable.
It is a further object of the invention to provide a device that can measure the dimensions of a countersink that is portable based on existing gap measurement devices using laser beams.