Machine and method for making concrete reinforcing bars
OwnerFrank R. Potucekinventor
Life of this patent
Estimating the term…
Abstract
A machine for making concrete reinforcing bars, known as rebars, from wire stock having a round cross section. A preform roller station cold works the round cross section of the wire stock into the shape of a polygon. A first form roller station cold works the polygonal cross section into a cross section having a central core and radial fin members extending therefrom. A second form roller station further reduces the diameter of the central core, and further increases the radial extent of the fin members. A third form roller station reduces the core still further, and again increases the radial extent of the fins, imparts shoulder members that provide an anti-longitudinal slip function at preselected intervals along the extent of the rebar, and roughens the rebar.
Claims43
A machine for making rebars, comprising:
- a supply of wire stock having a substantially round cross section;
- a preform roller station including a plurality of preform roller members having annular edges;
- means for feeding a continuous length of said wire stock from said supply to said preform roller station;
- said plurality of preform roller members being equidistantly and circumferentially spaced relative to a path of travel of said wire stock;
- said plurality of preform roller members imparting a generally polygonal cross section to said wire stock;
- a first form roller station longitudinally spaced apart from said preform roller station;
- said first form roller station including a first plurality of form roller members having convex annular edges;
- said first plurality of form roller members being equidistantly and circumferentially spaced relative to a path of travel of said wire stock;
- said first plurality of form roller members forming said wire stock into a wire stock having a central core and a plurality of equidistantly spaced, tapered fin members radiating therefrom;
- each of said fin members having a rounded terminus, and said fin members having a common dimension and configuration;
- the diameter of said central core being about one-third the diameter of an imaginary circle coincident with radially outermost edges of said fin members;
- a plurality of elongate, circumferentially spaced bight regions formed along the extent of said wire stock, there being as many bight regions as there are form rollers in said first plurality of form roller members;
- a second form roller station longitudinally spaced apart from said first form roller station;
- said second form roller station including a second plurality of form roller members having convex annular edges;
- said second plurality of form roller members being equidistantly and circumferentially spaced relative to a path of travel of said wire stock;
- said second plurality of form roller members further forming said wire stock by further reducing the diameter of said central core, further reducing the amount of taper of said fin members, and further lengthening the radial dimension of said fin members relative to the core diameter, taper, and fin length imparted to said wire stock by said first plurality of form roller members;
- a plurality of transversely disposed notch members formed on the convex annular edges of each of said second plurality of roller members;
- said notch members being equidistantly and circumferentially spaced about the respective annular edges of said second plurality of form roller members;
- and
- a plurality of transversely disposed, longitudinally spaced, raised shoulder members being formed along the extent of said wire stock by said notch members;
- each of said raised shoulder members extending across its associated bight region.
The machine of claim 4, wherein said roughening means is acid washing.
A method of making rebars comprising the steps of:
- feeding a substantially continuous length of wire along a predetermined path of travel;
- forming a plurality of longitudinally extending, circumferentially disposed, substantially flat surfaces in said wire so that it has a polygonal cross section;
- thereafter forming a plurality of circumferentially spaced concave bights in said wire by passing said wire through form roller means so that each bight is centered with respect to an associated flat surface so that metal is forced out of a core of said wire into plural fin-shaped projections that are separated from one another by said bights;
- forming a plurality of equidistantly and circumferentially spaced, transversely disposed shallow notch means in the respective annular edges of said form roller means to form a corresponding plurality of transversely disposed raised shoulder means in said rebar as an anti-slipping means, each of said raised shoulder means extending across its associated bight.
Dependencies are inferred from the claim text.