This invention relates to a flexible inspection system for use in both industrial and medical applications and, more particularly, to an elongated, flexible, fiber-scopic inspection device having internal vertebrae for independent support and articulation.
Elongated tubular inspection devices, particularly such devices incorporating flexible fiber-optics, are often used to inspect sites which would not normally be visible to the human eye. The jet engine is one type of mechanical structure for which such inspection would be most useful, particularly to inspect the 1st stage, or high temperature stage, of the engine just behind the burner can which has components that are most subject to wear and deterioration. The arrangement of the jet engine's rotor and stator blades, particularly those in the high temperature stage of the engine, presents a most complex geometry which has not been amenable to inspection in the past other than by first disassembling the engine. There has been a need for some form of inspection device which can be placed near the rotor and stator blades, and other important sites within the engine, for the inspection thereof without the laborious task of disabling the engine. The use of this type of instrument would effect a substantial savings in the cost of maintenance of the engines. Savings would result from the man-hours saved by avoiding the disassembly and reassembly of the engine. Additional savings would result from the increase in service time of the engine since the downtime for maintenance would be substantially reduced.
A further appreciation of such tubular inspection devices can be more readily attained by considering those currently in use in the practice of medicine. For instance, a common form of such a device, known as an endoscope, is used for inspection of the human colon while a similarly structured device is used for inspection of the urethra. The endoscope is conventionally used in the diagnosis of tumors and other conditions in the lower gastrointestinal tract. The endoscopic examination involves the physician observing the intestinal wall through an eyepiece in the control head of the instrument. Generally, the endoscope is provided with a source of illumination at its objective end, the end which is placed adjacent the area to be examined, and a bundle of light-transmitting fibers through which an image of the examined area is transmitted back to the eyepiece. The endoscope can further incorporate a channel which provides a washing fluid for application to the site under examination as well as a surgical tip and other features.
A factor to be considered in the construction of the endoscope for its normal medical use is its flexibility and articulation which permits the objective tip to be directed along the channel of the colon. An endoscope can be made to traverse a considerable distance within the colon providing that any bends in the colon have sufficiently large radius of curvature to enable the objective end of the endoscope to be readily articulated to follow the course of the colon. Care must be taken, however, to precisely guide the instrument so as not to puncture the colon wall, especially as the device is being inserted.
A problem arises in using presently available flexible devices for the internal inspection of complex articles of manufacture such as interior regions within jet engines. For example, certain compartments within the engine, such as the aforementioned regions within the turbine, are at present effectively inaccessible to viewing by an inspector. Such inaccessibility is the case even with the use of an inspection device such as an endoscope because the articulation of the inspection device requires some sort of guiding surface, such as the interior wall of the colon, to orient and support the inspection device. A jet engine has an interior characterized by relatively open spaces and few appropriate supporting surfaces readily available to guide the objective end of the inspection device. In addition, presently known endoscope designs, even when used for their originally intended purpose, are not easily able to negotiate all colon configurations without substantial risk of puncturing the colon wall.