Abstract: A safety spring lock for locking an air pattern control in a diffuser includes a normally bowed strip carrying a retainer clip. The strip is flattened to engage the clip with a fixed part of the diffuser, the clip engages the diffuser and that engagement and the inherent bias of strip hold the spring lock in place in the diffuser. The safety lock includes a U-shaped portion spaced from the retainer clip and connected to the retainer carrying portion by a normally bowed strip which is flexed to a flattened position to locate the U-shaped portion adjacent to portion of the movable air pattern conrol when it part of the diffuser. The U-shaped portion is urged into engagement with a portion of the air pattern control to prevent movement thereof in the diffuser which would otherwise be sufficient to remove the air pattern control from the diffuser.

Abstract: An air distribution device system includes an air distribution device of rectangular configuration and an auxiliary frame adapted to flush-mount the air distribution device within a ceiling of the type wherein ceiling material is directly fastened to overlying structural members such as joists or rafters. The auxiliary frame is substantially rectangular in form and is fashioned from elongate frame members of T-shaped cross section. The vertical portions of the T-shaped frame members are fastened to the structural members so that the horizontal portions of the frame members are substantially coplanar with the ceiling. Thereafter, the air distribution device rests upon, and is supported by, the horizontal portions of the frame members. When desired, the air distribution device can be raised off the auxiliary frame to obtain access to the interior of the ceiling.