Abstract: A drum construction for an overhead garage door lift assembly includes a spiral groove comprised of three connected sections each having a distinct sequence of radii to facilitate raising and lowering of a multi-panel garage door mounted on a track in a manner which avoids undesirable surface impact of the door upon closing and enhances torque energy for lifting from the closed position.

Abstract: An overhead, rolling door includes a peripheral seal construction that restricts air flow heat transfer through the periphery of a door opening. The door comprises a flexible curtain mounted on an overhead drum located above the door opening. The curtain may be unwound from the drum and lowered to close the door opening and engages the seal to preclude air flow energy loss through the door opening. The seal is comprised of unitary, elastomeric, elongate, flexible blades mounted on brackets positioned around the periphery of the door opening. The blades function as flexible cantilever mounted seals with an outer end that fits tightly against the surface of the closed door to form an uninterrupted seal of the closed door opening.

Abstract: A closure apparatus for closing an opening in a partition with a frame disposed around the opening includes a drum member rotatably mounted to the partition at the top end of the opening. It also includes a curtain member secured to the drum member. The curtain member winds around the drum member to move out of the opening in the partition; and it extends from the drum member to close the opening. A counterweight connected to the drum member offsets the weight of the curtain member; and a reducing weight reduces the weight of the counterweight to allow the curtain member to drop from a raised position. An activating assembly engages the reducing weight with the counterweight and allows the curtain member to unwind from the drum member and close the opening.