Patent ID: 8031039

Claim:
A separate-type magnetic shield apparatus comprising a plurality of magnetic shield side wall bodies in the longitudinal direction; wherein said plurality of magnetic shield side wall bodies are combined mutually to form therein a substantially cylindrical space around the longitudinal axial line extending horizontally, and at least one of said magnetic shield side wall bodies moves relative to the remaining magnetic shield side wall bodies and is made separable therefrom; wherein each of said plurality of magnetic shield side wall bodies has a magnetic shield outer side wall body having one of the magnetic bodies which are combined mutually to form therein said cylindrical space, and joint magnetic shield side walls having magnetic bodies which project from the both longitudinal end edges of said magnetic shield outer wall outwardly in the radial direction to said cylindrical space; and wherein conductors extending in the longitudinal axial direction of said cylindrical space are provided on said magnetic shield outer wall of said magnetic shield side wall body to supply current therethrough; and whereby disturbing magnetic fluxes coming from said magnetic shield side wall body on one side horizontally to said magnetic shield side wall body on the other side are deflected upwardly or downwardly by means of the magnetic field produced around said conductors to thereby prevent the magnetic fluxes from flowing into said cylindrical space.