US3024527A - Method of producing concrete form ties and the like - Google Patents

Description

March 13, 1962 F. E. BUYKEN METHOD OF PRODUClNG CONCRETE FORM lIEIS AND THE LIKE Filed Feb. 18, 1958 FIG FIG

FIG 4 FIG FRANK E. BUYKEN FIG United States Patent 3,024,527 IWETHGD F PRODUCING CONCRETE FORM TIES AND THE LIKE Frank E. Buylken, 8620 Island Drive, Seattle 8, Wash. Filed Feb. 18, 1958, Ser. No. 715,906

' 3 Claims. (Cl. 29509) This invention relates to improvements in the method of producing concrete form ties and the like and, more particularly to the method of producing flanges on such ties to act as stops when the ties are used to space apart or spread a pair of opposed form walls.

Briefly, a concrete form tie is a metal bar having buttons or heads formed on the extreme ends to receive Wedges or other attachment devices at the outside of the form walls. Intermediately, such a rod is provided with one or more break points that weaken the rod to such extent that, when it is imbedded in concrete and is twisted from outside the concrete, the rod will break within the wall and thus permit the removal of the protruding ends. It will be understood that the wall panels of the form are usually lumber or plywood sheets provided with prelocated holes to receive the ends of the form ties. Between the button heads and an adjacent break point such a rod must include stop means, preferably of flange shape, to abut the form inner face to permit spacing or spreading as between two form walls. I

It is among the salient objects of this invention to provide an improved method of manufacturing flanged form ties, and to provide a novel method of attaching and locating flange washers on the tie rods as required and desired.

Another object of the invention has been the provision of a method of producing flanged form tie in which the flange is secured to the tie rod in a manner that avoids reducing the strength of the rod at the point where the flange is attached, particularly avoiding the weakening effect of crystallization due to heat processing or a reduction in mass due to cutting into the rod body.

Other objects have been the provision of a method of manufacturing a form tie which lends itself to modern high-speed manufacturing processes and requirements in order that the volume of production may be economically and efficiently obtained with simple tools and relatively unskilled labor.

In essence my method of producing an annularly flanged form tie comprises circumferentially uniformly swelling a metal tie rod in an area spaced from an end to a diameter greater than the normal diameter of the rod. I form a washer with an axial opening greater than the normal diameter of the rod and less than the diameter of the swelled area. Assembly of the form tie is obtained by sliding the washer onto the rod end of normal diameter and forcing the washer onto the swelled area of the rod to a position normal to the axisof the rod and where it is frictionally retained. In carrying out this method a variation involves forming an annular outstanding shoulder on the swelled portion of the rod, the shoulder being so located that when the washer is forced on to the swelled portion from the rod end of normal diameter it comes into abutment with the shoulder.

Another feature of novelty of this invention is the provision of a form tie resulting from the described method. The invention in its method and apparatus aspects is shown and described in the accompanying drawings in a preferred form together with related modifications. Changes and modifications and variations fairly falling within the scope of the subjoined claims are contemplated as a part of the instant invention. Throughout the drawings like reference characters refer to like parts.

2 In the drawings: FIGURE 1 is a perspective view of a tie rod embodying the invention;

FIGURE 2 is a view taken in the plane 2-2 of FIG- URE 1 with a tie rod per se shown in cross section;

FIGURE 3 is a fragmentary perspective view of an end portion of a modified tie rod according to the invention;

FIGURE 4 is a face view of a washer;

FIGURE 5 is an enlarged cross section view showing a washer of FIGURE 4 attached to a rod as in FIG- URE 1;

FIGURE 6 is an enlarged cross section showing the washer of FIGURE 4 attached to the rod of FIGURE 3;

FIGURE 7 illustrates a modified form of washer; and

FIGURE 8 is an enlarged cross section showing the washer of FIGURE 7 attached to a rod as in FIGURE 1.

FIGURE 1 shows a rod 10 of metal which has been struck or deformed to provide break points 12 in its middle area. Outward of break points 12 and inward from each end, rod 10 is swelled to provide the enlarged portion 14. Preferably the swelling of the rod 10 is accomplished cold as, for example, by securely gripping the rod on each side of the area to be swelled and while so gripped sharply and briefly moving the gripping means together whereupon the intermediate area of the rod is shortened and outwardly bulged as shown in FIGURE 1.

For illustrative purposes only let it be assumed that the normal rod diameter is 0.250 inch. A desirable bulge would have a maximum diameter of 0.3125 inch. Those portions of the bulge 14 intermediate the greatest diameter thereof and the normal diameter of the rod preferably constitute sloping surfaces merging substantially smoothly with each other at the point of greatest diameter and quite smoothly with the normal rod diameter whereby to provide at least one inclined surface for purposes that will later become apparent.

Referring to FIGURE 4 the Washer 16 has an axial opening 18 which is slightly larger than the normal rod diameter and slightly smaller than the greatest diameter of the bulge 14. It will be apparent that under these circumstances the washer 16 can easily be slipped over the rod end 15 of normal diameter but that it cannot be easily moved onto the bulge 14 except under conditions of substantial pressure to move it longitudinally along the rod.

Again for illustrative purposes, typical dimensions being given, the opening 18 is preferably 0.002 to 0.004 inch in diameter greater than the normal rod diameter of 0.250 inch thus permitting an easy slipping fit. Normally the washer will be formed of metal softer than the rod so that when the washer 16 is pressed on to the bulge 14 it will be forced up the inclined surface and be caused to swell slightly. In this manner an extremely tight frictional engagement is obtained between the washer and the rod at the bulge portion.

Normally rod 10 will be provided with a pair of washers 16 each located inward a pre-determined distance from the end of the rod and spaced apart according to form wall spacings desired. The rod 10 is upset to provide a button head 20 as shown in FIGURE 1 for attachment by clamping or securing means outside a concrete form wall.

In FIGURE 3 I show a modified form of rod 10 having break point 12, normal end 15, and a bulge 24 which is characterized by having an annular shoulder 26 in that part of the bulge away from the free end of the rod 10. The shoulder 26 is formed during the swelling or bulging of the rod and, illustratively, may extend circumferentially of the bulge to an overall diameter of approximately 0.003 to 0.004 inch beyond the greatest dimension of the bulge 24. The production of shoulder 26 is accomplished by confining the area of the rod being bulged in die walls the sizes and contours of which comply to the dimensional requirements as illustratively described above.

An assembly of washer 16 with the rod of FIGURE 3 appears as in FIGURE 6. In this instance the washer 16 has been forced on to the bulge 24 until it has reached a point of abutment with annular shoulder 26 where it is caused to outstand normal to the axis of the rod 10.

In FIGURE 7 I illustrate a modified form of washer 36 which has an opening 38 at its center. The periphery of opening 38 is provided with self-cutting thread elements 40 as shown and described in my copending application, Serial No. 715,907, filed February 18, 1958. The washer 36 may be used for flanging rod 10 having bulge 14 of FIGURE 1 or bulge 24 of FIGURE 3 in which case the assembly will be as appears in FIGURE 8. Rather than applying the washer by straight line force it is preferable to spin washer 36 on in a threading action whereupon matching thread elements 41 will be cut in the bulge 14 by the thread cutting elements 40 of the washer 36. It will be apparent to those skilled in the art that the washer 36- may similarly be applied to a shouldered rod of the type shown in FIGURE 3. Any metal particles cut by the thread elements 40 from the bulges of the rod escape through the relief notches 42 between the interrupted thread elements.

It will be understood that the working of the rod 10 to provide bulges 14 or 24 results in a hardening and stiffening of the rod material as well as in a dimensional increase circumferential of the rod. When either washer 16 or washer 36 is disposed on the rod there will be no weakening of the rod beyond its normal strength. As a result the rod at the point where the washer is attached is normally stronger than at the break points 12. This insures that when the rod is subjected to twisting for the purposes of breaking it after the concrete has hardened the break will certainly occur within the concrete wall and not at its face or in the close proximity of the flanged washer on the rod.

Tie rods according to this invention may be fractured or broken blind while the form panels are still in place on the hardened concrete. This facilitates the removal of the form panels and eliminates the necessity of unseating the panels from the protruding, firmly held tie ends which may often be bent or misaligned during erection or filling of the forms. In this way the stripping of the forms is facilitated.

By carefully controlling the relative size between washer opening 18 and the larger diameter of swelled portions 14 or 24, it is possible to position the washer normal to the rod axis but not so tightly thereon that, upon rotation of the rod while the washer is embedded in concrete, the rod may nevertheless turn freely. This gives a definite advantage when forms are being stripped in that the mechanic need only revolve the rod to effect its fracture at the break point and the washer will not revolve thus eliminating damage to its embedding concrete.

Having thus described my invention, I claim:

1. The method of producing an annularly flanged form tie, comprising: circumferentially, uniformly swelling a metal tie rod in an area spaced from an end to a diameter greater than the normal diameter of the rod and providing a sloping surface merging between the normal diameter of the rod and its end and the greater diameter of the swelled portion, selecting a washer with an axial, circular opening greater than the normal diameter of the rod and less than the diameter of the uniformly swelled area, sliding said washer onto said rod end of normal diameter to close proximity with the swelled area, and forcing said washer onto said sloping surface of the swelled area of the rod to annular flange disposition therearound, whereby said Washer is caused to swell slightly and is secured in tight frictional engagement on the form tie substantially perpendicular to the axis of the rod.

2. The method of claim 1 in which, simultaneously with the swelling of the rod, there is included the step of forming an annular outstanding shoulder on the swelled portion and facing the rod end, and the washer is forced onto the swelled portion into abutment with said shoulder.

3. The method of claim 1 in which the forcing of the washer onto the swelled portion is accompanied by simultaneously rotating one element relative the other element.

References (Iitcd in the file of this patent UNITED STATES PATENTS 1,142,820 Knauf June 15, 1915 1,805,124 Wilcox May 12, 1931 2,107,130 Schenk Feb. 1, 1938 2,152,962 Ice Apr. 4, 1939 2,193,078 Schenk Mar. 2, 1940 2,222,339 Schenk Nov. 19, 1940 2,276,050 Leighton Mar. 10, 1942 2,494,128 Holmquist Jan. 10, 1950 2,564,372 Phelps Aug. 14, 1951 2,657,449 Hillberg Nov. 3, 1953 2,657,455 Hillberg Nov. 3, 1953 2,775,018 McLaughlin Dec. 25, 1956

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