US2657449A - Tie rod for concrete wall forms - Google Patents

Description

Nov. 3, 1953 B. HILLBERG 2,657,449

- TIE ROD FOR CONCRETE WALL FORMS Filed March 2, 1949 2 Sheets-Sheet l B. HILLBERG Nov. 3, 1953 Filed Marc Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE Bror llillberg, Qh-icago, 111., assignor to Superior Concrete Accessories, Inc., Chicago, 111., a corr ation of Illinois Application ,March Z, 1949, Serial No. 79,141 cci i s. (01. 25-131) The pre ent invention r lates en al y to ti rods for use in concrete construction. More par,- t l rly the invent on relates to that WPBj-fl .ti rod-which is designed f r us wi h a pai of spaced apart, vertically extending wall forms having opposi ely disposed :holes therein an wedge variety attaching .devices outwards of the holes, is adapted when in use to extend horizontally and :have its ends project through the holes in the forms and attached to the attaching devices, has stop-forming washers directly inwards of its .ends forenga-gement .withthe inner surfaces of the hole defining portions of the terms, embodies at predetermined distances inwards of the washers 'breakeoff points and inwards of the break-oif-poi-nts flats, serves while in its operative position and in connection with pouring of con-- crete between the forms to hold the forms against inward andioutwarddisplacement, and is adapted after hardening of'the concrete, release of the attaching devices and removal or .dismantlement of the forms, to haveits projecting ends bent at substantially right angles and then turned or twisted inorder to break or sever them from the central portionof the rod at thebreak-off .points within the .side faces of the concrete wall.

In connection'with the fabrication .ofa {tie rod of this type it has heretofore been proposed to utilize a rod formedof steel of aicertain hardness and after formationof the break-off points and flats by suitable dies, to mount conical washers of harder steel on the rodat the proper locations ouwards of the break-off points. After mounting or proper positioning of the washers the latter are flattened .in any suitable manner :inorder to cause such contractionof the inner margins that the washers-become interlocked with the .rod. in practice it has been found that a tie rod that is formed or fabricated in accordance with the aforementionedtechnique or methodis subject to several objections. In the first place, flattening of the conical washers-results in the corners .of the inner marginsof .the washers so digging into the adjacent portions oftherodthat they rupture or sever thesteel fibers of the rod to such anextent that when the ends of .the rod are bentand twisted they break off adjacent-the washers instead of at the break-off .points. In the event that the ends of thettie-rodibreakcif at the stopforming washers instead of at theinwardly disposed break-oif points the portions of the rod between the actualbreak-offs and the -,in tended break-01f points are either left in place or .remov d- ,I left in p ac uc po tion becaus the outer ext m i h re a flush wit the 2 side faces of the concrete wall, are unsightly and in connection with rusting thereof discolor the concrete. If the portions are removed difiiculty is encountered in connection with the removal operation and itis generally necessary to deface or chip away the concrete around the portions. Another objection .to a tie rod, the washers of which are mounted in place as heretofore indicated, is that the washers grip the adjacent portions of the tiered withsuch force or so tightly that when the projecting endspf the rod are bent at right angles and turned in connection with the break-off operation the washers turn with the rod ndsnd hen spe e conc e e u t washers, thus necessitatingacostly patching operation.

One of the principal objects of this invention is to provide atierod which is an improvement upon, and-eliminates the objectionsof, previously designed tie r-odsan d ischaracterized by the fact that the stop-forming washers are fi-at whenoriginally mounted on the rod and have the inner margins thereof so compressed .by the action of suitable dies that they are inwardly extruded in such manner as to form in the adjacent portions of the rod shallow annulargrooves which are of arcuate crosssectionand are so interlocked with the extruded portions of the inner margins of the washers thatthe washers areheld against longitudinal or axialdisplacement with respect to the rod, while at the same time they permit the rod, inconnection with turning of the projecting ends thereof, to rotate relatively thereto. By having the washers [mounted on the rod .in this manner there-is no cutting or rupture of the fibers of the rod-that-are within the washers and hence in connection with bending and turning of the project.- ing ends of the rod the ends break on" at the break-off points instead of at the washers. In addition, the projecting ends of vthe rod in connection with break-off turn relatively to the washers and hence the washers do not effect spalling of the portions of the concrete .in which they are embedded.

Another object of the invention is to provide a tie rod which is generallyof new and improved construction, efiectively a'nd efliciently fulfills its intended purpose and is capable .offlbeing .projducedatalow cost. i

Qther objects of-the invention and the various advantages and characteristics of the presentltie rod will be apparent from a consideration of the following detailed description.

The inventionconsists in the several novel tures wn e l eres ite s iie ti an a 3 more particularly defined by claims at the conclusion hereof.

In the drawings which accompany and form a part of this specification or disclosure and in which like numerals of reference denote corresponding parts through the several views:

Figure l is a side view of a tie rod embodying the invention; I

Figure 2 is a view, partly in side elevation and partly in vertical section, showing the tie rod in operative or connected relation with a pair of spaced apart, vertically extending wall forms having oppositely disposed holes therein for re ceiving the ends of the tie rod and wedge variety attaching devices outwards of the holes for con- 4 nection to the outer projecting extremities of the tie rod;

Figure 3 is a view partly in side elevation and partly in section showing the tie rod of Figure 2 after removal of the wall forms following hardening or solidification of the concrete, and illustrating the manner in which the projecting ends of the rod are bent at right angles and then turned to effect break-off at the break-oil points that are inwards of the stop-forming washers;

Figure 4 is an enlarged fragmentary longitudinal section illustrating in detail the construction and design of the stop-forming washers on the rod and showing the manner in which they are mounted on the rod and so interlocked there- :11:

with that they are held against longitudinal or axial displacement with respect to the rod while at the same time permitting the ends of the rods to turn relatively thereto in connection with a break-off operation;

Figure 5 is a plan view showing the coacting washer compressing dies before they are actuated to extrude the inner margin of one of the washers so as to cause it to form in the adjacent portion of the rod a shallow annular groove of arcute cross section;

Figure 6 is a horizontal section showing the coacting dies after they have been actuated so as to extrude by compression the inner margin of the stop-forming washer therebetweemand Figure 7 is a plan view showing the dies in retracted open position after a washer compressing operation.

The tie rod which is shown in the drawings constitutes the preferred form or embodiment of the invention. It is designed and adapted for use in connection with a pair of spaced apart, vertically extending wall forms 8 and serves, in conjunction with a pair of wedge variety attaching devices 9, as hereinafter described more in detail, to hold the forms against inward and outward displacement during pouring of concrete between the forms for purposes of forming a vertical wall. The forms 8 are of standard or conventional construction and each, as shown in Figure 2, consists of a rectangular panel In and a rectangular reenforcing frame H on the outer side of the panel. The frames II of the forms 8 have pairs of horizontal, spaced apart intermediate crosspieces I2 and these are adapted to be positioned in horizontal alignment when the forms are in their operative or concrete wall forming position. The holes I3 are formed in the panels I0 between the central portions of the crosspieces I2. When the tie rod is in its operative position with respect to the forms 8 its ends project through the holes I3 and between and beyond the frame crosspieces I2 as shown in Figure 2 of the drawings. As well understood in the art, the forms 8 are arranged in an opposed laterally spaced, upstanding position preparatory to pouring of concrete therebetween. In connection with positioning of the forms the ends of the tie rod are inserted through the holes I3 in the panels III of the forms. After insertion of the ends of the tie rod through the holes the wedge variety attaching devices 9 are applied so as operatively to connect the tie rod to forms. As soon as the devices 9 are connected to the extremities of the tie rod the tie rod serves to hold the forms 8 in proper position. Formation of a concrete wall is accomplished by pouring concrete between the two forms. After hardening or solidification of the concrete the attaching devices 9 are withdrawn from the extremities of the tie rod and the forms are removed from the concrete wall by shifting them outwards. After removal or dismantlement of the forms the projecting ends of the tie rod are bent at right angles and turned in order to break or sever them from the central portion of the rod at points inwards of the side faces of the concrete wall.

The tie rod is formed of comparatively hard steel to the end that it possesses the desired tensile strength. It is designated in the drawing by the reference numeral I4 and for the most part is circular in cross section. Preferably the tie rod is formed of inch steel stock, the carbon content of which is approximately of 1%. As shown in Figure l of the drawings the tie rod is provided with heads I 5, stop-forming washers I6 inwards of the heads, break-off points I? inwards of the washers, and flats I8 inwards of the breakoff points. The heads I5 are formed at the extremities of the tie rod I4 and when the tie rod is in its operative position are located small distances outwards of the crosspieces I2 of the form frames II. They are slightly smaller than the holes I3 in the panels I!) and, in connection with use of the tie rod, are adapted to abut against the outer surfaces of the attaching devices 9, as shown in Figure 2. The attaching devices 9 are downwardly tapered and have longitudinal slots therein. They are adapted after application to the outer ends of the rods to be driven downwards between the heads I5 and the frame crosspieces I2 and serve to clamp the forms against the stop-forming washers I6. The latter, as described hereafter, are mounted on the rod I4 against longitudinal or axial displacement relatively thereto and serve when the tie rod is in its operative position to prevent inward movement of the forms 8. The break-off points I! are located but comparatively small distances inwards of the stop-forming washers I6 and are in the form of opposed pairs of notches. When the projecting ends of the tie rod are bent at right angles and then turned or twisted after removal of the forms 8 from the concrete wall they break off at the break-off points II. The flats I8 are formed on the central portion of the tie rod I4, i. e., the portion of the rod that is embedded in the concrete and serve to prevent rotation of the central portion of the tie rod in the concrete when the ends of the rod are turned or twisted for break-off purposes. It is contemplated that the break-off points and flats will be formed before the stop-forming washers I6 are mounted on the rod as described hereafter.

The washers I6 are formed of harder steel than the tie rod proper. Preferably they are formed of steel stock of 14 gauge and with a carbon content of approximately of 1%. The washers before mounting on the rod are flat and have an internal diameter slightly greater than the diuded portions 322 inwards of the grooves. Due to the manner in which the inner margins of the washers are compressed between the dies {9 and 120 the extruded portions 22 are segmental in cross section. in connection with thecom- "pressing operation the "extruded portions 22 compress the adjacent portionsofthe tie rod proper seas .to form therein annular grooves 23 which are of arcuatecro'ss' section and coact with the extruded portions 22 to .hold the washers I6 against longitudinal or axial displacement with respect to the rod. Due to the cross sectional shape sof the extruded portions 22 and the-maniner in which such portions are formed,;-tl ie steel fibers of the portions of the rod that are within the washers are not cut or ruptured and hence auiacent the washers the rod is :not so weakened that connection with turning of the projecting .iemisnf the rod it will break on at the washers in- The grip be- 1 stead of the break-01f points II. tween the extruded portions 22 of the Washers and the adjacent groove portions of the rod is such that the washers and rod are normally not relatively rotatable but when the ends of the rod are turned for break-off purposes such ends will turn relatively to the washers and hence not cause the washers to rotate and cause or effect spalling of the portions of the concrete wall in which they are embedded. The annular grooves 2I which are formed in connection with compressing of the inner margins of the washers I6 are inwardly tapered and extend approximately half way through the washers. As best shown in Figure 4 of the drawings the grooves 2| are trapezoidal in cross section.

The dies I9 and which are utilized to compress the inner margins of the washers I6 into interlocked relation with the adjacent portions of the rod are disposed one opposite the other as well as in spaced apart relation, as shown in Figures 5, 6 and 7. The die I9 is a split die and consists of a pair of complemental, oppositely disposed sections 24. The latter are movable to and from one another and have in the opposed faces thereof full length grooves which are semicircular in cross section and when the sections 24 are in abutment with one another define a cylindrical hole through which the tie rod is adapted to extend. The faces of the sections 24 of the split die I9 that are opposite the die 20 are fiat and coplanar. The die 20 is mounted in a tubular guide 26 to slide to and from the split die I9. It has a centrally disposed, open ended, rod-receiving hole 21 in coaxial relation with the grooves 25 in the opposed faces of the sections 24 of the die I 9 and embodies on the end face thereof that is adjacent the die I9 an annular rib 28. This rib is disposed directly outwards of the adjacent end of the hole 21 and is outwardly tapered so that it is trapezoidal in cross section. The portion of the outer end face of the die 20 that is outwards of the rib 28 is fiat. as shown in Figure 6.

In connection with mounting of one of the washers on the tie rod proper, the washer in truly fiat form is mounted between the two dies I9 and 20 in such manner that its hole is in centered relation with the hole in the die I9 and the hole '21 in the die '20, it being understood that insertion of the washer into place or position occurs while-the sections '24 ot the-die 1 9 are-m abutment, as shown in Figure After-proper position-mg of the washer one end QT the tiered I4 is inserted through the hole in the die F9, the hole in the'washer and the hole 2-! in the die' zil. As soon as one end of the rod is -inserted to the proper extent the movable die 29 is slid towards the 'die I9 until the annular rfib '23 on the*o uter end thereoffbe'comes fully embedded in the inner margin of" the washer. In connectionwith -emfbedmentof the rib the inner margin 'jo'f the washer 'is 'deformed by compression so that it embodies the annular inwardly tapered groove and the inwardly extending extruded portion 22. Such portion, in connection with formation thereof, is forced into the 'adiiacentlportion of the rod and "forms the shallow annular groove which, as heretofore pointed out, coacts with the extruded portion to hold the washer against axial displacement with respect to the rod; hitter deformation of the inner margin of the washer the movable die 20 is retracted and these'ctioi-is '24 of the die I9 are spread apart or separated. Thereafterthe rod with thewasher mounted "on one end thereof is removed from the two dies I9 and 20. The other washer is mounted on the other end of the tie rod in precisely the same manner. After mounting of the two washers on the rod the heads I5 are formed on the extremities of the rod.

The herein described tie rod is characterized by the fact that due to the particular manner in which the stop-forming washers are mounted on the rod proper the ends of the rod, in connection with a break-off operation, will break off at the break-off points I! instead of within the washers. It is further characterized by the fact that although the washers are fixedly held against longitudinal or axial displacement with respect to the rod, the ends of the rod during twisting for break-off purposes are permitted to turn relatively to the washers and hence there is no likelihood of the washers spalling the portions of the concrete in which they are embedded. Due to the manner in which the washers are mounted on the rod the tie rod as a whole may be manufactured or fabricated at an extremely low cost and eifectively and efflciently fulfills its intended purpose.

The invention is not to be understood as restricted to the detail-s set forth since these may be modified within the scope of the appended claims without departing from the spirit and scope of the invention.

I-iaving thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. As a new article of manufacture, a tie rod designed to hold a pair of concrete wall forms in spaced apart relation, formed of a piece of metal of circular cross section and certain hardness, having a portion thereof inwards of one of its ends weakened to form a break-off point, and embodying at a comparatively small distance outwards of the break-off point an originally fiat circular form-engaging washer formed of harder metal and having at one side thereof and spaced a small distance from its inner periphery a concentric die-formed inwardly tapered truly continuous annular groove whereby the portion of the washer inwards of the groove is extruded inwards and is caused to be of shallow segmental cross section and to form in the contiguous portion of the rod without rupture of the fibers thereof or weakening it to the same extent as the weakened portion of the rod, a shallow correspondingly shaped truly continuous annular groove by which the washer is so interlocked with the rod that it is positively held against displacement lengthwise of the rod while at the same time it grips the rod tightly but permits the rod to turn relatively to it in response to application of a comparatively heavy turning force to the rod while the washer is held against rotation.

2. As a new article of manufacture, a tie rod designed to hold a pair of concrete wall forms in spaced apart relation, formed of a piece of steel of circular cross section and certain hardness, having spaced apart portions of its central part weakened to form break-off points, and embodying at comparatively small distances outwards of the break-off points but inwards of its extremities originally flat circular form-engaging washers formed of harder steel and having at one side thereof and spaced a small distance from their inner peripheries concentric die-formed inwardly tapered truly continuous annular grooves whereby the portions of the washers inwards of the grooves are extruded inwards and are caused to be of shallow segmental cross section and to form in the contiguous portions of the rods without rupture of the fibers thereof or weakening them to the same extent as the weakened portions shallow correspondingly shaped truly continuous annular grooves by which the washers are so interlocked with the rod that they are positively held against displacement lengthwise of the rod while at the same time they grip the rod tightly but permit the rod to turn relatively to them in response to application of a comparatively heavy turning force to the rod while the washers are held against rotation.

BROR HIILBERG.

References Cited in the file of this patent UNITED STATES PATENTS

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