Abstract: Disclosed is a device for generating and measuring the flow of a gas, the device being particularly adapted for measuring the magnitude of air infiltration in a building and for locating sources of air infiltration. The device of the invention comprises a propeller-type fan for generating gas flow mounted in a gas flow guide, a drive for rotating the fan, an orifice plate located upstream from the fan, a damper or drive controller for varying the gas flow rate through the orifice, and one or more flow-directing vanes between the orifice plate and the fan, the plane of the orifice plate being approximately parallel to the plane of rotation of the fan, and the orifice and fan being generally concentric and spaced less than one fan diameter apart.

Abstract: A stair nosing is constituted by an edge base made of a hard material and adapted to be installed on the tread of a stair step, and an edge bead cushion formed on a surface of the edge base so as to be located at the stair tread nosing of the stair step. A positioning groove is formed on the surface of the edge base behind the edge bead cushion, and a gripper is adapted to be set in the positioning groove and to be secured to the edge base. The edge base is provided with a riser cover integrally formed at the front edge thereof so as to be positioned on the riser of the step in a manner to fit over the stair tread nosing. The gripper is composed of a sheet member adapted to be positioned in the groove and a number of spaced nails projected from the surface of the sheet member.

Abstract: In combination, a vertically slotted panel wherein the vertical slots provide a constricted throat entrance and an internal enlarged pocket to captivatingly nest a keeper which is sized and arranged for limited rotation in the pocket into and out of locking engagement with the side walls of the pocket and which constitutes a clamp member by reason of a screw extending through it and through a force distribution plate sized to overlay the throat margins and from which a support arm extends perpendicularly to the panel so that it is adapted to be tightened into clamping relation in any of a wide variety of locations on the panel by means of screws.