Patent Number: 041587790
Section: claims

1. Shielding device for the protection of human embryo cells from the effects of radiation during examination by X-rays comprising a radiant absorbing protective screen including a central radiant absorbing protective plate of predetermined configuration, a plurality of additional radiant absorbing protective displaceable sheets and adjusting means to displace the sheets relative to each other to vary the covering surface area of the screen. 2. Device according to claim 1 including a supporting frame to which the protective screen is rotatably secured for rotation of the screen within its own plane. 3. Device according to claim 2 wherein the plate and sheets are composed of lead. 4. Device according to claim 3 wherein the plurality of sheets comprises pairs of first lead sheets movable at right angles for enlarging or reducing the covering area of the protective screen and further including second lead sheets mounted in pairs and being rotatable operatively on one pair of the first sheets, pressure means for correspondingly rotatably biasing the second sheets, and cam members disposed on another pair of the first sheets on which the second sheets are freely and slidably supported. 5. Device according to claim 4 including holders associated with the adjusting means to which the pairs of sheets are secured, the pairs of sheets being synchronously and oppositely displaceable. 6. Device according to claim 5 wherein the holders comprise slides having a rack-like extension provided with teeth, a pinion for meshing with such teeth for displacement of all the sheets and a knob for rotating the pinion to displace the sheets. 7. Device according to claim 6 wherein the associated pairings of sheets are arranged in various movement planes, and all of the sheets are displaceable relative to each other in the direction of the corresponding planes of the sheets. 8. Device according to claim 1 including a closed casing completely enclosing the protective screen, the casing comprising an upper part and a lower part and having on one such part a conical surface inclined in the direction of radiation. 9. Device according to claim 8 wherein the casing comprises two identical parts of plate-like shape, the parts being joinable by an annular contact surface provided on the edges of such parts. 10. Device according to claim 8 wherein the casing is composed of transparent material. 11. Shielding device for the protection of human embryo cells from the effects of radiation during examination by X-rays comprising a radiant absorbing protective screen including a central radiant absorbing protective plate of predetermined configuration, a plurality of additional radiant absorbing protective displaceable sheets and adjusting means to displace the sheets to vary the covering surface area of the screen, the central plate and displaceable sheets being arranged to provide a protective screen of elliptical shape which shape is retained over the entire range of adjustment of the adjusting means. 12. Device according to claim 11 including an adjusting ring for adjusting the entire protective screen comprised of the central plate and displaceable sheets between two alternative adjustments which deviate from each other by an angular displacement of 90 degrees. 13. Device according to claim 12 including a supporting arm to which the protective screen is connected and a support column for the supporting arm on which arm is vertically adjustable. 14. Device according to claim 13 wherein the supporting arm is a telescopically adjustable arm. 15. Device according to claim 12 including a pivot arm support for supporting the protective screen as a parallelogram guide.