Shutters for X-ray scanners

摘要

Rotary safety shutter mechanisms for use in computerized tomographic X-ray scanners of the type wherein a source of radiation and a detector means are mounted for movement on opposite sides of a medium in order that the radiation passes through successive planar sections of medium and is attenuated and detected to give an output. The safety shutter mechanisms are arranged to be positioned adjacent the outlet aperture of the radiation source to selectively block the outlet upon occurrence of a predetermined condition. Two different embodiments of safety shutter mechanisms are disclosed. In each embodiment, the mechanism comprises a housing mounted adjacent the outlet aperture and having a through passage through which radiation from the source can pass. A cylindrical shutter member is carried in the housing transversely of the passage and mounted for rotary movement between a first position which permits the flow of radiation from the source and a second position which blocks the flow. In the first embodiment, the shutter member is moved from the second to the first position by a linear solenoid connected with the shutter member through a crank which is continually biased to move the shutter to the second position. In the second embodiment, the shutter member is actuated to the first position by a rotary solenoid aligned with the axis of rotation of the shutter member and directly coupled thereto.