US2266912A - Device for bending structural sections - Google Patents

Description

Dec. 23, 1941. SHAW, JR 2,266,912

DEVICE FOR BENDING STRUCTURAL SECTIONS Filed Mafoh 20, 1939 I INVENTOR. @906 60% L A ORNEYJ Patented Dec. 23, 1941 umrs orrice Ralph M. Shaw, Jr., Edgewater Park, N. J., as-

signor to Pedrick Tool '& Machine Company, Philadelphia, Pa., a. corporation of Pennsyl- Vania Application March 20, icsa seriai No. 262,825

2 Claims.

This invention relates to a device for bending angle irons, channels, I-beams, strips, bars, and similar objects, and more specifically for bending such objects of different sizes with one standard form or die.

In general, it is an object of the invention to provide a device of the character described which will efliciently perform the purposes for which it is intended, which is simple and economical of construction, which can be expeditiously, conveniently and safely manipulated, and which can be readily manufactured and assembled.

Another object of the invention is to provide a device with which angle irons, etc. may be bent more than 180 degrees and then be easily removed from the device; to provide such a device which may be readily converted for use in bending objects of different thicknesses and sizes; and to provide such a device which uses the forces of compression rather than the forces of rolling.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements,

plified in the construction hereinafter set forth and the scope of the application of which will be'indicated in the claims.

For a fuller understanding of the nature and and arrangement of parts which will be exemobjects of the invention, reference should be had 'to the following detailed description, taken in connection with the accompanying drawing, in which:

Figure 1 is a plan View of a machine embodying one form of the invention;

Fig. 2 is a plan view, somewhat exaggerated and partly in section, of certain of the elements shown in Fig. 1; v 1

Fig. 3 is an exploded view in elevation of the form which is a part of the machine shown in Fig. 1 and an article to be bent thereagainst;

Fig. 4 is an exploded view of the formv shown in Fig. 3;

Fig. 5 is a view similar to Fig 3 of a different form and an article bent against it through an angle of more than 180 degrees.

It is desirable on occasion that metal articles which originally are straight, i. e., have successive, spaced, identical cross-sections, should be sometimes termed the outer surface.

I-beams, Ts, H-beams, Z-beams, or other standard or'special shapes, as well as bars, tubes, strips, and the like have been bent through arcs and angles. Heretofore that bending has introduced a packing together of the material of the bent article along that surface which has been made shorter by the introduction of the bend. A stretching or a tension has been correspondingly introduced into the article along that surface which has been made longer and which is Somewhere in the article there has been a line, plane or surface, called the neutral axis, at which there has been no compression or tension, the material on one side thereof being compressed and the material on the other side thereof being stretched or under tension.

There are certain materials and certainnew alloys which have very little ability to stretch and which do not stand up under tension. They do not lend themselves to bending operations described above.. The present invention contemplates a method and apparatus for. bending the before-mentioned structural sections which method and apparatus yield a product having a neutral line relatively close to the surface which is under tension, the material on that side being so close to the neutral plane that the degree of tension is negligible whereby materials which could not be bent without rupture may, by this method, be safely, and satisfactorily bent through any desired angle. .These structural sections are of material originally of low ductility or are in any angular form which has been obtained by rolling and/or from which most of the ductility has been removed. I I

A form or die is'also provided which, itself,

may be taken apart so that an article, which has -moved by any convenient source. of power such 45 as gear I4 at its periphery. A die I6 is attached at the center of the table through a stationary spindle as by nuts and bolts l8 through the head thereof. There may be dowel-s 20 passing through the several parts .of the die and resting on table I2, including the .end pieces :bent. Structural sections, i. e., channels, angles, article to be bent. It may be a bar seating beare rotated about the central die l6.

tween end pieces 22. Its surface facing the axis of die 16 may be flat or it may be irregular, depending on the piece to be bent. Means are provided for pushing bar 24 inwardly along a radius of die l6. These means are also capable of moving longitudinally of bar 24. Thus, a roller 26 is slidable radially of the table on ways 28 which are attached to the table. The roller axis is perpendicular to the table. The roller may be annular and rotatable around a central post having a dove-tailed mounting fitting into recessed portions of ways 28.

One example of a die or form is shown in Figs. 3 and 4. That particular die comprises two circular, flat end pieces 22 between and'coaxial with which are a plurality of circular laminations 30 and another plurality of circular laminations 32 of smaller radius, the latter being segregated against one end piece. That one 34 of the larger laminations which is next adjacent the smaller laminations may have a rounded-off edge, as shown, to fit the surface of the material to be bent. Such a die may be used to bend an angle iron 36. The inner face of one flange 38 (one of the structural elements of the angle iron) sits against the edges of the laminations 30. The inner face of the other flange 40 (another structural element of the angle iron) sits against the exposed side of lamination 34. A sufiicient number of small laminations 32 provide space for the other flange to have a close slip or a press fit between lamination 34 and end piece 22.

In operation, the angle iron is placed against die l6 as described. One end of the iron is against the resistance stop 42 which is fixed to the frame It]. The die wiper piece 24 is pressed against flange 36 so that the latter is held tightly between the two dies, preferably under compression but not pressed beyond the elastic limit. The flange 36 and die bar 24 are pressed together over a considerable length ahead of the point at which bending is taking place. The table l2, tracks 28, roller 26 and bar 24 As they rotate, the angle iron is bent. The roller rolls on die bar 24, but the latter does not move with respect to the angle iron. The flange 40 undergoes compression. The edge of that flange is under the greatest compression. Points of that flange successively inward of the outer edge are under less and less compression. The neutral plane, where the metal is neither compressed nor stretched, is along the line NN in Fig. l, which is not the same as that which results when an angle is being bent as a beam. The flange 3B is so close to the neutral plane that even points on its outer face are under substantially no tension (stretching). For that reason, stainless steel which cannot stand tension, is able to be bent in this machine.

The article being deformed may be bent through an angle of more than 180 degrees to a shape, for example, like that shown in Fig. 7. Obviously, it cannot be then removed from the die 36 by a motion perpendicular to the axis of the die IS. The dowels 20 and bolts I8 may be removed, the end piece 22 taken off and the deformed article lifted off by moving it parallel to the axis of, and thereby away from, the die I6.

In Fig. there is shown a modification of the die IS in which one group of smaller laminations 32 .is between the larger laminations 30 and one end piece 22 and another group of smaller laminations 32 are between the larger ones and the other end piece. Such a die may be used to bend a a channel beam or an I-beam. In any case, one or more laminations may be added to or taken from the die so that it may acconnnodate an article of any predetermined size of cross-section. Furthermore, the laminations may have any desired arcuate and/or polygonal periphery.

If the article to be bent is arcuate in crosssection, for example a pipe, the inner die may take the shape shown in Fig. 6 of end pieces with concave edges. In this case, too, there may be laminations between the end pieces of successively different diameters whereby the die in cross-section has a concave rim.

The present method and device is able to bend a metallic bus bar edgewise. Such a bending is an example of the ability of the present method and device to bend, around vertical axes, sections having considerable horizontal width compared to their heighths, without thinning the outer surface of the bend, i. e., without causing the vertical dimension of the outer surface of the bend to shrink appreciably, and without extruding metal in a vertical direction from the inner surface of the bend. The cross section of the material at the bend, after it has been bent, is substantially unchanged in cross-section. Thus, a rectangular bus bar, positioned to have a horizontal cross-section 36" x 3" and a vertical cross-section 3" x may be bent in a horizontal plane around a vertical axis so that one of its 36" x A surfaces becomes the inner bent surface and so that such inner surface is only slightly increased in thickness, if at all,and is not crumpled. As in the case of other structural sections, the metal may be cold and may be hard drawn copper, brass, bronze, duraluminum, stainless steel, Monel metal, and other alloys.

The lack of distortion in the cross-section at the bend is characteristic of the product described above. The machine and method bend full circles and even coils of pipe, tube, strip or shape and substantially without distortion. This type of bending may be termed one plane bending. A bar horizontally straight may be bent around a vertical axis so that after bending it may still be laid on a horizontal straight edge without deviation therefrom,

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In combination, a device for bending structural sections and the like comprising a form having a surface against which one face of an angle iron may be pressed, a second form which is coaxial with the first-mentioned form and which has a surface against which the edge of another face of the angle iron may be pressed, end elements having areas of cross-section perpendicular to the axis of said device which are larger than similar areas of the respectively adjacent forms, said elements being axially removable away from said forms and means for temporarily holding one of said end elements and the first-mentioned form in a press fit respectively against the two surfaces of such angle iron which are adjacent such a before-mentioned edge of such an iron.

2. A device for bending structural sections comprising a form having a surface against which one face of an angle iron may be pressed, a second form which has a mutual axis with the first-mentioned form and which is of smaller cross-section than said first form whereby a flange of such an angle iron may extend from said face toward the axis of said device, and

angle iron which is moved perpendicularly to ward said parts.

RALPH M. SHAW, JR.

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