Patent ID: 7083116

Claim:
A boom arrangement for use in a car wash comprising: a mounting member for fixed attachment to a support; a flexible hose for receiving a wash-spray device on one end of the hose and a water supply device at the other end of the hose, a boom for supporting a substantially horizontal portion of the hose, a rotatable coupling carried on the fixed mounting member for supporting an inner end of the boom so that the horizontal portion of the hose can rotate about a vertical axis in a generally horizontal plane with the remainder of the hose extending downwardly from the horizontal plane at an outer end of the boom; and a parking arrangement for moving the coupling, the boom and the hose to a parked location at a specific angular location around the vertical axis; the parking arrangement comprising a cam and a cam follower, one of the cam and the cam follower being mounted on the mounting member and the other on the boom such that the cam follower moves relative to the cam as the boom rotates about the vertical axis; the cam follower being spring biased into engagement with the cam so as to generate a force tending to rotate the boom about the vertical axis; the cam being shaped so as to define a parked position of the boom in which the spring bias is at a minimum potential energy and a position remote from the parked position in which the spring bias is at a maximum potential energy; and the cam being shaped so as to define a substantially constant gradient in both clockwise and counterclockwise directions around the axis from the remote position to the parked position so as to define a substantially constant parking force toward the parked position.