US2418383A

US2418383A - Bar stock and reinforcing bar

Info

Publication number: US2418383A
Application number: US615226A
Authority: US
Inventors: Wennberg Odd; Joseph D Stites
Original assignee: WEGNER MACHINERY CORP
Current assignee: WEGNER MACHINERY CORP
Priority date: 1945-09-08
Filing date: 1945-09-08
Publication date: 1947-04-01
Anticipated expiration: 1964-04-01

Description

April 1947- o. WENNBERG ET AL 2,413,333

BAR STOCK AND REINFORCING BAR Filed Sept. 8, 1945 w .T a A m M 2 50 PRIOR AIQT INVFNTOHS. TA/vmbe Patented Apr. 1, 1947 BAR STOCK AND REINFORCING BAR Odd Wennberg, Manhasset, and Joseph D. Stites,

New York, N. Y., assignors to Wegner Machinery Corporation, Long Island City, N. Y., a corporation of New York Application September 8, 1945, Serial No. 615,226

3 Claims. 1

This invention relates to-reinforcing bars for for use in concrete structures and the like, and particularly to that type of bar which comprises two rod-like sections joined in substantially parallel alignment by an integral intermediate Section, or web, of lesser cross-sectional area than either of said rod-like sections, which type of bar is twisted around its longitudinal axis before use to form, in effect, a helical structure comprising two helices having a common axis. The use and purpose of such bar and the reasons for twisting the same are all well known, and it is likewise well known to provide on this type of bar ribs arranged on the outer surfaces of the bar, usually transversely, diagonally or spirally thereof, hereincalled transverse ribs, for the express purpose of increasing the strength of the bond be tween the bar and the concrete or like material in which it is set or contained.

An object of this invention is to provide a bar stock of the above type which, when twisted and used as a reinforcing element, forms with the concrete or similar substance in which it is set a bond of great strength. i

A further object of the invention is to provide a twisted reinforcing bar of the type above described having such relation between its elements that the action of corrosive elements in the concrete in which the bar is set will be minimized.

Other objects and advantages will be apparent from the following description of the invention with respect to the specific embodiments thereof which are illustrated in the attached drawing:

In the drawing:

Fig. 1 is a plan view of bar stock, before the twisting operation, embodying the principles of this invention;

Fig. 2 is a cross-sectional view of the bar stock shown in Fig. 1;

Fig. 3 is a side View of the bar shownin Fig. 1;

Fig. 4 is a plan view of another bar stock, be-

fore the twisting operation, embodying the prin- Fig. is a perspective view of bar stock, such as that shown in Fig. 1 after it has been twisted into a reinforcing element;

Fig. 11 is a perspective view of a portion of a bar twisted from stock of the type illustrated in Fig. 9.

Referring to the drawings, the bar shown in Figs. 1 to 6, inclusive, embodies thebasic elements representative of the type of bar above described which has been used or proposed for use as a reinforcing element in concrete or like struc-, tures. The bar comprises the two rod-like sections 15 which are joined in substantially parallel alignment by the intermediate section or web Hi. This web has a cross-sectional area which is less than that of either of the rod-like sections. The

rod-like sections are usually roughly, or approximately, circular in cross-section, by which is meant that they are circular, elliptical or ovate in shape, the exact shape forming no part of this invention and varying somewhat according to the specific method of manufacture, which is usually some type of rolling process. The web 16 may bear the proportion shown in the drawing to the rod-like sections l5, or it may be thicker or wider, its specific shape and size being no part of the present invention. It will be noted that the general shape formed by the web section and the tworod-like sections is'roughly that of a dumbbell, and many different and specific shapes of this dumbbell form have ben shown and described in the art. Running along the outer surface of each rod-like section I 5 and longitudinally thereof is the longitudinal rib 11. It is usually present in reinforcing bars of the type here under discussion because the manufacture of the bar by rolling is simplified if a certain amount of metal, as represented by the longitudinal rib I1, is provided between the millrolls during the bar shaping operation. The transverse ribs 18 are added to the bar for the principal purpose of increasing the bonding action between the bar'and the concrete or similar substance in which it is set and also for the purpose, in some instances, of increasing the strength or tensile properties of the bar. These ribs may be of different shapes. They may be truly transverse, as shown in Figs. 1 and 3, in the sense that they lie at right angles to the longitudinal axis A of the bar, or they may be diagonally formed in the bar, as shown in Figs. 4 to 6, in which case they are, in the sense of this invention, transverse of the bar.

Heretofore when these transverse ribs have been placed upon the bar they have extended across the web connecting the two rod-like sections of the bar. In one example of prior art form, such as shown in Fig. 8, the transverse ribs were placed across the web to strengthen the same as well as to provide bonding effect, and in this case the ribs 20 did not extend over any large portion of the surface of the rod-like section-s l9.

In another form of bar used prior to this invention, illustrated in Fig. 9, the transverse ribs 22 extended over the entire surface of the rodlike sections 2| as well as over the entire surface of the web 23. We have discovered that the provision of a transverse rib across the web which connects the .rod-like sections is detrimental to the performance of the bar in the concrete.

In accordance with this invention, the transverse ribs extend only over surfaces, or a portion of the surfaces, of one or both of the rod-like sections of the bar and do not interrupt or extend over the surfaces of the intermediate section, or web, of the bar. The differences between the bar of this invention and the bars of the prior art are best shown by a comparison of Figure 7 with Figures .8 and 9, Fig. '7 representing a typical embodiment of this invention. It will be noted that in Fig. '7 the transverse ribs extend only over surfaces of the rod-like sections 26 and do not interrupt the surfaces of the web or intermediate section 21, whereas in Figs. 8 and 9 the web section is interrupted by the transverse ribs. The advantage and benefits of the bar of this invention over the bars previously used lie in the fact that there is no pocket formed, when the bar stock is twisted, which will trap moisture, air or any liquid or gaseous media when the bar is set in the construction form and the concrete rises around the bar. in the use of twisted reinforcing 'bars which embody transverse ribs which pass across the Web or intermediate section,- the pocket formed between the rib and the surface of the web section during twisting will trap moisture and air during the time that the concrete is being pouredaround the bar. This moisture or air thus trapped prevents a complete concrete-metal contact in the area of the pockets and, therefore, diminishes the bonding strength of the total bar. the air and moisture thus trapped therein attack, in a relatively short time, the surface of the metal "bar, which is usually steel, and start acorrod-ing or oxidizing process at that point which may finally utterly destroy the cross-sectional integrity of the bar or at least diminish its strength and consequently the strength of the reinforced structure of which it is a part.

Figp'lO, showing in perspective a section of bar stock such as shown in Fig. 1 twisted into a reinforcing element, when compared with Fig. 11, which shows in perspective a portion of the bar stock illustrated in Fig. 9 twisted into a reinforcing element, illustrates the advantageous differenceswhich are obtained-when, in accordance with this invention the surface of the web is uninterrupted by the transverse ribs otherwise provided on the surface of the rod-like section-s. Referring to Fig; 11, the twisting of the bar stock into the form of a twisted reinforcing element We have discovered that Moreover,

has caused the ribs 22 to slope sharply where they pass over the web surface 23, thereby forming pockets 3!) which trap moisture-laden air. or moisture and air as the concrete rises upwardly around the bar, whereas, the bar shown in Fig. 10 does not, when twisted, form pockets over the web It since the ribs I8 terminate at a point short of the surface of the web Hi. It will be noted that the benefits and advantages of this invention are realized no matter what may be the peripheral or cross-sectional shape of the transverse ribs and no matter what may be the spacing of the ribs with respect to the longitudinal axis of the bar or with respect to each other, so long as the surface of the intermediate section or web which connects the two rod-like sections of the .bar is not substantially interrupted by the transverse ribs. The transverse ribs may terminate on the surface of the rod-like section somewhat short of the surface of the web section, or the ribs may blend into the edge of the web section, but, in accordance with the principles and teachings of this invention, the transverse rib is not disposed across the surface of the web section.

The reference to specific forms and shapes in the foregoing description has been by way of example and with no intention of excluding such equivalents as fall within the intent and spirit of the invention and the language of the appended claims.

We claim:

1. A bar adapted to be twisted around its longitudinal axis to form a reinforcing element, said bar comprising two elongate rod-like sections joined in substantialy parallel alignment by an integral web of cross-sectional area less than the cross-sectional area of either of said rod-like sections and outwardly extending integral transverse ribs spaced at intervals on the surface of said bar, the surface of said integral web being uninterrupted by said ribs.

2. A bar adapted to betwis-ted around its longitudinal axis to form .a reinforcing element, said b-ar, comprising two elongate rod-like sections joined in substantially parallel alignment by an integral web of cross-sectional areailess than the cross-sectional area of either of said rod-like sections and outwardly extending ribs integral with the surface of said elongate rod-like sections and transversely spaced at intervals thereon, said ribs merging into the surface of said rod-like sections so that the said integral web has asurface/uninterrupted by said ribs.

3. A twisted reinforcing element comprising two elongate rod-like sections longitudinally joinedl'by an integral web, said element being twisted about its longitudinal axis into a helical structure comprising two helices .having a common axis and outwardly extending integral transverse ribs spaced at intervals on the surface of said; element and merging into the surface of.

said rod-like section, the surface of'said web being uninterrupted by said ribs.

ODD WENNBERG. JOSEPH 'D. STITES.