Abstract: A vehicle wash boom apparatus includes a fixed journalling tube for journalling a boom-supporting tube for reciprocal and rotational movement about a vertical axis. The journalling tube carries a cam and the boom-supporting tube carries a cam follower. A pair of torsion springs at all times bias the cam follower in an upward direction against a cam surface of the cam which is inclined relative to the vertical axis. Thus, as the boom is rotated, the interaction between the cam and the cam follower effects a vertical movement of the boom-supporting member which allows the boom while being used to by-pass a like boom of an identical apparatus when in its home or parked position.

Abstract: A car wash boom system of the present invention includes a low pressure washing brush boom and a high pressure pre-rinsing/rinsing wand boom which are mounted for relative rotation about side-by-side generally vertical axes. The washing brush boom includes first and second opposite end portions and a medial portion therebetween with a first and second portions being generally parallel to each other and the medial portion being normal thereto. A cam follower is carried by the second end portion of the washing brush boom and rides along a generally circular cam surface whose axis is the vertical axis of rotation of the washing brush boom. The second offset portion of the washing brush boom is mounted for rotation about a generally horizontal axis which is normal to its vertical axis of rotation.