Optical rail system

Claim 1

A rail system comprising, in combination: a plurality of associated optical rails, each said rail having a uniform crosssectional shape throughout its length, a first longitudinally extending flat bearing surface, a second longitudinally extending flat bearing surface parallel to said first surface and four flat locating surfaces on the sides of the rail, each locating surface extending towards a central plane of the rail perpendicular to the bearing surfaces from a line contiguous to the edge of a said bearing surface at an angle of about sixty degrees to the first bearing surface for cooperation with corresponding surfaces in grooves of couplings and optical carriers, said grooves also having surfaces for cooperating with the bearing surfaces, said rail cross section having a portion in a plane parallel to the bearing surfaces at a point adjacent to where the end of a locating surface is closest to the central plane with a width in the range of one third to one fourth of the width of a said first bearing surface, and wherein the combination further includes a coupling part joining two of said rails so that they are positioned in parallel planes at angles to each other, said coupling part having an first groove and a second groove identical in shape each receiving a rail portion, each groove having a bottom contacting a bearing surface and each groove having a side surface complemental to and contacting a said locating surface and a set screw urged against a locating surface and cooperating with each groove to 13 secure a said rail to said groove and an optical carrier having a groove identical in shape to the grooves of the coupling part receiving a portion of a rail and a set screw cooperating with said groove to secure said rail to said carrier for carrying an optical instrument.