Patent Number: 053965337
Section: description

DESCRIPTION OF THE PREFERRED EMBODIMENTS The principles of the present invention are particularly useful when incorporated in a primary radiation diaphragm illustrated in FIGS. 1 and 2 for a ray beam 2 emitted by a radiation transmitter or emitter 1. For gating the ray beam 2, the primary radiation diaphragm comprises at least one diaphragm plate, but preferably four diaphragm plates, 3, 4, 5 and 6, wherein two of the plates 3 and 4 form a diaphragm plate pair that are arranged in a plane 8 (FIG. 1) and the plates 5 and 6 form a second pair and are arranged in a second plane 7, with the planes 7 and 8 extending parallel to one another and the pairs being offset 90.degree. relative to one another and oppositely adjustable relative to one another. A single mount 9 is provided for the plate 3, a the single mount 10 is provided for the plate 4, a single mount 11 is proved for the plate 5 and a single mount 12 is provided for the plate 6. The mounts 9 and 10 are engaged in a first guideway 13, while the mounts 11 and 12 are engaged in a second guideway 14. As illustrated, the first and second diaphragm plates 3 and 4 are adjusted along the first guideway 13, which proceeds in the plane of the drawing of FIG. 1, while the third and fourth diaphragm plates 5 and 6 are adjusted along a second guideway 14 that proceeds perpendicularly relative to the plane of the drawing of FIG. 1. It is advantageous when the first guideway 13 comprises a first rail 15 and a second rail 16 that are disposed on the same side of the housing 19 of the primary radiation diaphragm and when the second guideway 14 is composed of a first rail 17 and a second rail 18 that are seated on the same side of the housing 19, but extend at right angles to the side having the guideway 13. When the mounts 9, 10, 11 and 12 of the diaphragm plates 3-6 are respectively connected on the first and second guide rails with the mount 9 having a part 20 which engages both the rails 15 and 16, the mount 10 having a part 21 which engages both the rails 15 and 16, while the mount 11 has a part 22 engaging both the rails 17 and 18 and the mount 12 having a part 23 engaging portions of the rails 17 and 18. The bearing support of the diaphragm plates 3 and 4 by the mounts 9 and 10 on the rails 15 and 16 or the bearing supports for the diaphragm plates 5 and 6 by the mounts 11 and 12 on the rails 17 and 18 are set forth in the exemplary embodiment with reference to the third and fourth diaphragm plates 5 and 6, whose mounts 11 and 12, respectively, as well as those of the first and second rails 17 and 18, are illustrated in FIG. 1. It is shown that every guide rail 17 has a first channel 24, a second channel 25 and a third channel 26, while the guide rail 18 has a first channel 27, a second channel 28 and a third channel 29, with these first, second and third channels being adjacent to one another, wherein the guide part, such as 22 of the mount 11 of the third diaphragm plate 5, will have a pair of spaced apart rollers 30 that are received in the first guide channel 24, a single roller 31 received in the guide channel 27 of the second guide rail which lies parallel to the rollers 30 and in the same plane. Also, the mount 22 will have a pair of spaced apart rollers 32 received in the second channel 25 of the first guide rail 17. Analogous to this, the guide part 23 for the mount 12 of the fourth diaphragm plate 6 has a single roller 33 engaged in the third channel 26 of the first guide rail 17, a pair of rollers 34 disposed in the third channel 29 of the second guide rail 18 and also a pair of roller 35 in the second guide channel 28 of the second guide rail 18. This arrangement allows each of the plates, such as 5 and 6, to be held in parallel to each other in the same plane. The oppositely-directed adjustment of the first and second plates 3 and 4 or the third and fourth plates 5 and 6 is set forth in greater detail in FIG. 1, which shows the arrangement for moving the first plates 3 and 4. However, the movement of the third and fourth plates is the same but at right angles. For oppositely-directed adjustment of the first and second diaphragm plates 3 and 4, the mount 9 of the first diaphragm plate 3 is connected to an upper part or run 38a of a toothed belt 38 by a connector, such as a clamp part 36, and the mount 10 of the second diaphragm plate 4 is connected to a lower part or run 38b of the toothed belt 38 by a connector part 37. The two runs 38a and 38b of the belt are aligned parallel to the planes 7 and 8 and extends between an idler roll 40 and a toothed pinion 39a (FIG. 2) on a shaft of a motor 39. Thus, dependent on the direction of rotation of the shaft of the motor 39, the plates 3 and 4 are either adjusted toward one another or away from one another. As illustrated in FIG. 2, a motor 41 with a pinion 41a, an idler 42 and a toothed belt 43 operate in the same way for moving or adjusting the third and fourth diaphragm plates 5 and 6 either together or oppositely away from each other. Within the framework of the invention, each mount 9, 10, 11 and 12 of the diaphragm plates 3, 4, 5 and 6 can also be mounted on the respective guide parts 21-23 at only a single guide rail when the parts 21-23 and the guide rails 15, 16, 17 are executed so that the diaphragm plates are guided in a defined fashion and are, thus, adjustable parallel to the plane. Of course, the channels of the guide rails can also be executed as webs with corresponding grooves or channels engaging therein for the guidance of the diaphragm plates. Although various minor modifications may be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent granted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.