Patent ID: 7415776
Filing Date: 2008-08-26
Classification: G01D,Y10S

Abstract:
1. A magnetic scale, comprising: an outside pipe member; an inside pipe member inserted in the inside of said outside pipe member such that at least a portion of an outer-most face of the inside pipe member is positioned in a spaced relationship to an inner-most face of the outside pipe member so as to form a gap between the outside and inside pipes, the inside pipe member having an outer circumference less than the inner circumference of said outside pipe member in order to allow for the gap to be formed; and a magnetic member in contact with the inside face of said outside pipe member and the outside face of said inside pipe member and extending in a linear direction, said magnetic member being inserted at least partially in the gap between the inner-most face of said outside pipe member and the outer-most face of said inside pipe member in such a manner as to extend in parallel to a longitudinal direction of said inside and outside pipe members, said magnetic member having a magnetic graduation formed thereon and magnetized alternately with N poles and S poles along the longitudinal direction thereof.