| 摘要 |
1,160,609. Making collimators; jointing. PICKER CORP. 31 Oct., 1967 [14 Nov., 1966], No. 49519/67. Headings B3A and B3V. [Also in Division H5] In manufacturing a multi-hole collimator, the flat external surfaces of a number of lead tubes are coated with adhesive, the tubes assembled with their longitudinal passages arranged substantially parallel to one another to form a honeycomb structure which has two end surfaces formed by the ends of the tubes and which substantially fills a supporting frame, and the adhesive is cured to bond the tubes together. The tubes are preferably of the same length, may be formed by impact extrusion, and thus may have one closed end, which closed end may be removed after curing by machining one or both end surfaces. One of the end surfaces may be shaped so as to have a concave cross-section so that it can be placed adjacent a corresponding convex input window of an image intensifier. The end surface may be shaped approximately to the desired crosssection by causing the assembled tubes to slide axially relative to one another prior to curing for distances such that the end surface approximates to the desired section, and after curing, machining the end surface to the desired section. To maintain the tubes in position during curing, a forming plate which abuts one of the end surfaces may be clamped to the supporting frame. In machining the cured assembly, the frame and the honeycomb structure are rotated about a central axis substantially parallel to the longitudinal axes of the tubes and a cutting tool is moved along a radius of each end surface so as to give that surface the desired cross-section after which the frame and honeycomb structure are rotated while the cutting tool is moved along a radius to give the same cross-section as previously, but the direction of rotation of the honeycomb structure relative to the cutting tool is opposite to that which occurred previously. Preferably, the radial movement of the cutting tool is from the perimeter of the end surface to its central axis. The tubes may be orientated in the frame and simultaneously coated with adhesive by means of a brushing action. After curing, interstices between the tubes are filled with an adhesive material mixed with a radiation absorbing material, and the honeycomb structure subsequently heated to harden the adhesive. The tubes used preferably have a hexagonal cross-section. If desired, during milling, the tubes are strengthened by being filled with a material which is subsequently easy to remove, e.g. paraffin wax. |
