Housing for cluster mills

A cluster mill housing of substantially the same size and form as a comparable monobloc mill housing and applicable to 20-high and 12-high cluster mills, said mill housing comprising a floor portion, a roof portion and a pair of bridge members, said floor portion having a central portion with a lower roll cavity formed therein, said central portion terminating in oppositely directed end portions, said floor portion having four corners at which four vertical columns are located respectively, said columns terminating in horizontal co-planar surfaces, said central portion, said end portions and said columns of said floor portion comprising an integral, one-piece structure, said roof portion having a central portion with an upper roll cavity formed therein, said central roof portion terminating in oppositely directed ears, each of said bridge members comprising an inverted U-shaped member with a beam-like body and downwardly depending ends terminating in co-planar horizontal surfaces, said horizontal surfaces of each bridge member abutting and being affixed to said horizontal surfaces of a cooperating pair of said columns, said bridge members overlying said roof portion ears, at each corresponding end of said central portion of said floor portion and said central portion of said roof portion a mill housing frame is formed, each mill frame being made up of a lower beam comprising the adjacent end of said floor portion, a pair of vertical column portions comprising the adjacent pair of said floor portion columns and an upper beam comprising the adjacent ear of said roof portion and the adjacent one of said bridge members, a pair of adjustment screws supported in each bridge member and bearing against the adjacent roof member ear, a synchronized drive assembly rotating said four adjustment screws equally and in the same direction to adjust the vertical position of said roof portion with respect to said floor portion, guide means fixing the horizontal position of said roof portion with respect to said floor portion, and hydraulic counterbalance assemblies affixed to said bridge members to support the weight of said roof portion and maintain said roof portion against said adjustment screws.