Mounting for a zoom lens

Claim 1

A mounting for a zoom lens having two lens members which are movable on either side of a fixed lens member, said two lens members moving in conjunction, and a movable focusing lens member which is adjustable independent in relation to the fixed lens member, each of said lenses comprising at least one lens or lens element, wherein the mounting comprises a single fixed tube having at least two angularly equidistant spaced internal projecting segments which are integral with the tube and which are limited internally to a bore of a diameter corresponding to that of the fixed lens member, and on which the said fixed lens member is mounted, an integral single movable member sliding inside the fixed tube and having integral longitudinal elements of the same number as the internal projecting segments on the fixed tube and of angular section complementary to the space between the segments, said elements being integrally connected at one end by extensions of the same angular shape of the element, to a first coaxial cylindrical annular part of an outside diameter less than the diameter of the fixed lens member, and inside which one of the movable lens members is mounted, and the elements being integrally connected at their other end to a second coaxial cylindrical annular part of an outside diameter greater than that of the fixed lens member inside which second part the other movable lens member is mounted, a bush mounting the movable focusing lens member and being focused by screw adjustment on the fixed tube.