US2918961A

US2918961A - Grip for straightening structrual sections

Info

Publication number: US2918961A
Authority: US
Publication date: 1959-12-29
Anticipated expiration: 1976-12-29

Description

Dec. 29, 1959 D. M. SEELEY 2,918,961

GRIP FOR STRAIGHTENING STBUCTRUAL SECTIONS Filed Feb. 6, 1958 2 Sheets-Sheet 1 INVE/V TOR DEWEY M. .SEELE) Attorney Dec. 29, 1959 D. M. SEELEY 2,918,961

GRIP FOR STRAIGHTENING STRUCTRUAL SECTIONS 2 Sheets-Sheet 2 Filed Feb. 6, 1958 Elms-L 3 INVENTOR DEM 5%? M11 A lforney United States Patent GRIP FOR STRAIGHTENING STRUCTURAL SECTIONS Dewey M. Seeley, Mount Lebanon Township, Allegheny County, Pa., assignor to United States Steel Corporation, a corporation of New Jersey Application February 6, 1958, Serial No. 713,608

1 Claim. (Cl. 153-35) This invention relates to the stretch-straightening of structural shapes or sections and particularly to grips facilitating such operation.

The straightening of rolled structural shapes of certain grades of steel as heretofore practiced has been slow as well as unsatisfactory as to the quality of results, and costly. It is accordingly the object of my invention to make possible a simple, quick and inexpensive method of accomplishing this result with a high degree of accuracy. More specifically, I subject a structural member such as a length of a rolled shape, while cold, to longitudinal tension exceeding the elastic limit and sufficient to elongate it slightly, while holding the ends in positively alined relation. For holding the ends, I provide novel grips adapted to exert pressure on both faces of the web and flanges of the shape. For applying tension, I employ a known stretching machine having headstock and tailstock with means for moving one of them.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating the present preferred embodiment In the drawings:

Figure 1 is a diagrammatic plan view showing an I-beam with its ends engaged by the headstock and tailstock of a tensioning apparatus;

Figure 2 is a partial section taken along the plane of line lI-II of Figure 1;

Figure 3 is a partial section taken along the plane of line III-III of Figure 2;

Figure 4 is a partial transverse section taken along the plane of line IVIV of Figure 3 with the parts of the grip in elevation; and

Figure 5 is a side elevation of the members forming a grip.

Referring now in detail to the drawings, in carrying out the invention, I insert the ends of a structural shape such as an I-beam into gripping head blocks, e.g., the headstock 11 and tailstock 12 of a tensioning machine provided with friction grips 13 as shown in Figures 2 through 5. The headstock and tailstock are fixed in alinement but movable apart axially by suitable power means (not shown) so as to permit tension to be applied to the workpiece to the extent necessary to elongate it slightly beyond the elastic limit.

The headstock 11 and tailstock 12 have openings 14 in their adjacent ends to receive the ends of the beam. The other ends of the headstock and tailstock have grip pockets 15 therein with outwardly flaring frusto-pyramidal walls. Wedge blocks 16, slidable on the side walls, have toothed surfaces engaging the outer faces of the flanges of beam 10. Wedge blocks 17, slidable on the top and bottom walls of the grip pockets, have wedges 18 on their inner faces.

Blocks

16 and 17 are dovetailed to the 2,918,961 Patented Dec. 29, 1959 pocket walls, corner blocks 19, disposed in the dihedral angles between the web and flanges of the beam, have their engaging surfaces toothed and an incline or bevel 20 adapted to engage one of the wedges 18.

It will be evident from the drawings that, when the several wedges and blocks are disposed as shown and tension is applied to the beam by moving the tailstock 12 away from the headstock 11, wedge blocks 16 will be forced against the outer faces of the beam flanges and wedge blocks 17 toward the web. The resulting spreading action of wedges 18 causes corner blocks 19 to be forced against the inner faces of the flanges as well as against the webs. The ends of the beam are thus held positively against angular displacement during the elongation under tension. The internal stresses causing camber or twist are efiectively eliminated by the flow of metal incident to elongation, leaving the beam straight and true throughout its length. Usually an elongation of 1 or 2% will sufiice for the purpose of the invention.

The grips disclosed are adapted without modification for engagement with a pair of channels disposed back to back or four angles engaged in pairs on each intersection of

blocks

16 and 19.

The advantage of the invention in addition to making possible a quick and easy method of straightening, is that the gripping load is distributed over all surfaces of the shape throughout substantially its entire area and the gripping pressure is fully equalized at various points. The grips automatically adjust themselves for slight variations from nominal dimensions of the workpiece within acceptable tolerances. Different sizes of beams, furthermore, may be engaged by the same grips by suitable adjustment of the wedging members.

Although I have disclosed herein the preferred embodiment of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

I claim:

A grip for frictional engagement with a structural member having a web and flanges at right angles thereto, said grip including a head block having a pocket therein defined by four frusto-pyramidal walls, the combination therewith of two wedge blocks dovetailed respectively into an opposed pair of said walls for movement therealong toward and from a member inserted in said head block to engage said flanges exteriorly, two wedge blocks similarly dovetailed, respectively, into the other two opposed walls, and corner blocks positioned within the head block and in the vertices between flanges and web having angularly related faces to apply pressure to opposite sides of said web and to engage the interior faces of said flanges, respectively, each of said last-mentioned wedge blocks having a wedging surface extending between the corner blocks on one side of said web, effective to spread them and thereby force them into engagement with said web and flange faces.

References Cited in the file of this patent UNITED STATES PATENTS 312,608 Button Feb. 24, 1885 1,966,955 Crampton July 17, 1934 2,040,678 Von Buskirk May 12, 1936 2,066,186 Mitchell Dec. 29, 1936 2,148,173 Rogoff Feb. 21, 1939 2,245,316 Amsler June 10, 1941 2,299,778 Wissler Oct. 27, 1942