GB296512A - Flexible endoscopic viewing tube - Google Patents

Abstract

296,512. Heimberger, H. July 5, 1927. Optical instruments.-The optical system of a flexible endoscope tube comprises pairs of rectangular prisms b, b<1> mounted in casings a with their short sides normal to the axis of the tube and their hypotenuses parallel to one another. The casings a are formed with obliquely disposed tubular extensions c fitting the one into the other and forming a swivel joint between the optical units. The members c are secured in coacting position by tangential pins d engaging annular recesses in the members. The arrangement is, such that light proceeding axially along the tube enters the prism b, is reflected at the hypotenuse face thereof and then at the longer rectangular face, which is silvered, and finally emerges from the prism normally to the hypotenuse face and in the axis of the swivel joint c. A complementary path is followed through the prism b<1>. The prisms b, b<1> are rigidly connected with adjacent prisms by members m containing the lenses of the system. The tube is covered by a flexible rubber sheath and is provided with a lamp having a protective sheath at its inner end. The optical units may be turned about theirpivots, to conform with the shape of bodily cavities, by cords e passing around the outer members e and led through guides in preceding members to the outer end of the instrument where they may be secured in any desired position. Air may be passed through the space between thesheath and the optical system.