US2292548A - Form tie - Google Patents

Description

Aug. 11, 1942. 1r. c. scHENK FORM TIE Filed March 14, 1941 .laila INVENToR 7&772115 cfn/ BY O 1 r Patented Aug. 11, 1942 UNITED STATES PATENT OFFICE FOR-M TIE Application March 14, 1941, Serial No. 383,292

2 Claims.

This invention relates to form ties usually used for holding together forms used in concrete work, and particularly to the type of form ties shown in Patents Nos. 1,238,696 and 1,970,946. In said patents is shown a form tie consisting of several parallel rods extending between the form boards, there being located between the rods at each end thereof a helix which is welded to the rods, each of the helices acting as a threaded member for the reception of the threaded end portion of a lag screw.

In some of the uses to which this form of tie is put, the tie remains embedded in the concrete structure with the ends at which the helices are located situated inwardly of the faces of the poured wall. To secure this result and so position the form tie that its ends are disposed inwardly of the resultant concrete structure, spacing members, usually in the form of cones to facilitate their removal after the concrete hardens, are interposed between the ends of the form tie and the inner faces of the form boards. These cones are each provided with a passage through which the lag screw passes to permit its engagement with the helix between the rods of the form tie.

At the present time, these cones are made of substantial size, due primarily to the fact that the inner or smaller end of the cone, which is the end disposed remotely from the form boards, must have a bearing surface to rest against, such bearing surface consisting of the ends of the rods of the form tie. Therefore, the diameter of the smaller end of the cone must be sufficiently large to enable it to abut squarely against the ends of the rods, with a resultantly larger diameter i which have to be pointed with concrete, which L often fell out at a later date, or was of a differ-- ent shade than the poured concrete and the patching accordingly showed up in the finished wall. In fact, in cases of so-called architectural concrete construction, where patching is seldom, if ever, permitted, form ties of the character above described were found unsuitable for the reasons mentioned.

The primary object therefore, of the present invention is to provide a form tie of the general construction of those above described, but which shall be provided with means by which much smaller spacing members or cones may be effectively used, whereby the formation of large holes in the wall structure and particularly at the op- CTI posite faces thereof, will be avoided and the holes so formed will be materially decreased in size. Another object of the invention is to provide means at the ends of the form ties which shall act as bearing surfaces for the inner, relau tively small-diameter ends of the spacing member or cones, such bearing surfaces consisting oi attened ends on the helices against which the inner ends of the cones may abut.

In the accompanying drawing, forming a part hereof, Fig. 1 is a sectional view through a concrete form, showing one of the improved form ties in position; Fig. 2 is an enlarged sectional view through one end of the form tie, the conical spacing member and a portion of the form boards; and Fig. 3 is an end view of the tie.

The tie consists of two or more parallel rods I, maintained in spaced apart relationship by means of the helices 2 and 3. Each helix is located at one end of the several rods and is secured between the same by being welded or otherwise secured in place. The helices each consist of a spirally formed length of rod constituting a thread for the reception of the threaded end 4 of a lag screw `5. E'ach lag screw extends through the longitudinally extending braces 6, between the vertical supports 1 and through holes in the form boards 8,

The form tie is so located that the ends of the same are spaced inwardly from the inside faces 9 and III of the form boards between which the concrete mass is poured so that when the lag screws are later removed after the concrete has hardened, the tie will be disposed within and located inwardly of the faces of the wall. Accordingly, conical spacing members I I are located between the ends of the tie and the inside surfaces of the form board to properly position the tie. Each cone has a centrally disposed, slightly tapered bore I2 to permit the passage of the lag screw, said bore terminating at the larger end of the cone in a square opening I3 into which a correspondingly shaped end of a wrench or othei tool is fitted, after the lag screw has been removed, to enable the cone to be rotated in the hardened wall to loosen it and remove it from the wall.

The smaller end I 4 of the cone is adapted to abut against the end of one of the helices, said end of the helix being provided with a fiat surface I5 constituting a bearing surface against which the small end of the cone may rmly abut. It will be noted from Fig. 3 that the attened end surface of the helix extends from the tip or extremity I6 of the helix to a point I'I substantially diametrically opposite, or in other words, through an area of 180 degrees or more. This has been found to constitute a flattened surface of suicient area to enable the end of the cone to rest firmly against the end of the tie.

In prior constructions, wherein spacing cones were employed, the projecting end of the helix prevented satisfactory contact of the end of the cone with the end of the tie unless the inner or smaller end of the cone was made of Suicient diameter to enable it to rest against the ends of the rods I rather than against the helix. Accordingly, such cones had to be made of relatively large diameter, resulting in the formation of correspondingly large openings in the wall surfaces. With the present arrangement, wherein a attened bearing surface is formed on the end of each of the two helices, the smaller end of the cone can be made approximately of the diameter of the helix, or even of less diameter, with a resultant decrease in the diameter of the larger end of the cone and a reduction in size of the holes made in the wall by the removal of the cones. Therefore, when this arrangement is employed, the holes formed in the wall are small and less noticeable; the pointing of the same with concrete is simplified and the chances of the small amount of concrete used in the pointing operation falling out of the lled holes is greatly minimized.

What I claim is:

1. A form tie consisting of several spaced-apart rods, a helix rigidly secured bet-Ween the rods at one end of the same and maintaining said rods in spaced relation, said helix having its end located adjacent to the ends of the rods provided with a flattened surface forming a seat for a spacing member, and a spacing member consisting of a cone having its smaller end disposed against and in abutment with the flattened end of the helix, the smaller end of the cone being of less diameter than the distance between the rods whereby said end of the cone abuts against the flattened end of the helix only and not against the ends of the rods, the cone having its larger end of less diameter than the greatest transverse width of the form tie whereby the hole formed in the concrete by said cone will be of less diameter than the lgreatest width of the form tie.

2. A form tie consisting of several spaced-apart rods, a helix rigidly secured between the rods at one end of the same and maintaining said rods in spaced relation, said helix having its end located adjacent to the ends of the rods provided with a flattened surface forming a seat for a spacing member, and a spacing member consisting of a cone having its smaller end disposed against and in abutment with the flattened end of the helix, the smaller end of the cone being of less diameter than the distance between the rods whereby said ends of the cone abuts against the flattened end of the helix only and not against the ends of the rods, the cone having its larger end of less diameter than the greatest transverse width of the form tie whereby the hole formed in the concrete by said cone will be of less diameter than the greatest width of the form tie, said at end of the helix against which the smaller end of the cone abuts beginning at the extremity of the helix and terminating at a substantially diametrically opposite point on the ie 1x.

TAMIS C. SCHENK.

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