Joist with nailing strip and positioning members

Claim 1

A form member for use with a mold for making a pretensioned concrete member having a nailing strip molded therein, the mold having a longitudinally extending, generally channel-shaped portion in which said form member is adapted to be disposed to form a nailing strip, said channel-shaped portion of said mold including a bottom surface and opposed walls, said form member comprising: a. a longitudinally extending, channel-shaped member having 1. a bottom wall adapted to be disposed in contacting engagement with the bottom surface of the channel-shaped portion of said mold, 2. a pair of side walls, each of which has a longitudinally extending upper edge, 3. a longitudinally extending U-shaped portion formed along the upper edge of each side wall, the longitudinal axis of each Ushaped portion lying in a plane disposed generally parallel with a plane in which is disposed said bottom wall, the bight of said U-shaped portion extending inwardly of its associated side wall, and 4. a longitudinally extending attachment-means-penetrating layer of material disposed within said channel-shaped member, said layer of material having a lower surface portion disposed adjacent the bottom wall of said channel-shaped member and upper surface portions disposed adjacent said U-shaped portions of said channel-shaped member whereby said U-shaped portions retain said attachment means-penetrating layer of material within said channel-shaped member and said layer of material prevents concrete from entering said channel-shaped member; and b. a plurality of positioning members longitudinally spaced along said channel-shaped member and securely disposed within the U-shaped portions thereof, each positioning member comprising 1. an inverted U-shaped frame member including a bight portion overlying said upper edges and a pair of leg portions, the outer surface of said bight portion being generally concave in configuration and adapted to engage pretensioning steel after the form member has been positioned within the mold, said frame portion lying in a plane disposed generally normal to the longitudinal axis of said channel-shaped member, 2. a pair of legs, each leg having (i) a first part attached to a corresponding one of the leg portions of said U-shaped frame member, and (ii) a second part securely disposed within a corresponding one of the U-shaped portions of said channelshaped member, said second parts lying in a plane disposed generaly normal to the plane in which is disposed said frame member, 3. the outer surfaces of the leg portions of said U-shaped frame member being spaced such that they are adapted to be received between the opposed walls of the mold in which same is to be used whereby said outer surfaces of said leg portions serve as means for centering and positioning said form member within the channel-shaped portion of the mold in which same are to be used upon being dropped therein and are adapted to be disposed adjacent the inside surfaces of the opposed walls of the mold in which same are to be used, and 4. said positioning members being constructed for transmitting a force to said channel-shaped member when positioned within the mold in which same are to be used and in contacting engagement with the pretensioning steel to be used within the mold.