Patent ID: 7092489

Claim:
An X-ray irradiator comprising: an X-ray tube having a flange formed so as to surround an X-ray output window, the flange having a notch formed in a peripheral edge thereof; a collimator box having an entry plate formed with an X-ray incidence window, the collimator box accommodating a collimator in the interior thereof; a ring provided on the entry plate so as to surround the X-ray incidence window, the ring receiving therein the flange of the X-ray tube and having a plurality of slots formed radially through the ring; a first tongue piece inserted through one of the plural slots from outside to inside of the ring by means of a spring, and fitted at a front end portion thereof into the notch formed in the peripheral edge of the flange; a lock device for locking the first tongue piece unlockably; a plurality of second tongue pieces being inserted through the remaining slots of the plural slots from outside to inside of the ring, and holding down a back side of the flange; a pair of half-rings each taking a partial charge of holding the plural second tongue pieces at positions outside the ring, the pair of half-rings, when one ends and opposite ends thereof are respectively opposed to each other, surrounding the ring in a state in which the plural second tongue pieces are inserted respectively into the plural slots, the opposite ends of the pair of half-rings being pivotally connected to the entry plate so that the one ends thereof can be opened and closed; and a connecting device for disconnectably connecting the pair of half-rings in a closed state of the one ends of the half-rings.