US2451531A - Wire tightener - Google Patents

Description

WIRE TIGHTENER Filed April 29, 1946 Ilig.4

23- l .1: limmh INVENTOR. Bug? J BRADLEY ATTORNE Y Patented Oct. 19, 1948 UNITED STATES PATENT OFFICE WIRE TIGHTENER Burt J. Bradley, Boise, Idaho Application April 29, 1946, Serial No. 665,873

7 Claims. Cl. 140-119) The present invention relates to improvements in wire tighteners, and has particular reference to a tightener adapted for use in connection with concrete forms.

Concrete forms are usually constructed of boards arranged in spaced and parallel relation to form a channel for receiving the concrete, stakes supporting the boards from the outside, spanning members between the boards and tie wires for drawing the boards toward the spacin members. The tie wires should be strong and well stretched to prevent the form from bulging outward under the weight of the freshly poured concrete.

In the present invention it is proposed to pro- Vide a convenient means for tightening the wire upon the form, that is particularly effective in tensioning the wire throughout the length thereof.

A wire may be tightened about an object by twisting the ends of the wire, and it also may be tightened by exerting direct pull on the ends of the wire.

In the present invention I propose to provide a wire tightener that will combine the two effects and will, in a single action, exercise lengthwise pull on the wire and twist theends of the wire about one another, either at the same time or in related order.

A mere twisting of the ends of the wire may be confined to a more or less local effect, whereas direct pull exerted on the ends of the wire will effectively tension the wire throughout the length thereof.

Thus, by combining the two efl'ects, it is proposed to provide a wire tightener that will take up the slack throughout the full length of the wire, and at the same time and in the same action, will twist the ends of the wire about one another to firmly hold the wire in tensioned condition.

Further objects and advantages of my invention will be disclosed as the specification continues, and the new and useful features of the same will be fully defined in the claims hereto attached.

The preferred forms of my invention are illustrated in the accompanying drawing forming part of this application, in which:

Figure 1 shows a perspective view of a concrete form having my wire tightener applied thereto;

Figure 2, a horizontal section through the device, with a slight modification;

Figure 3, a perspective detail view of a screw While I have shown only the preferred forms of my invention, I wish to have it understood that various changes or modifications may be made within the scope of the claims hereto attached,

without departing from the spirit of the invention.

Referring to the drawing in detail, Figure 1 shows the conventional set-up of a concrete form as comprising a pair of boards I set on edge in spaced and parallel relation, a series of stakes 2 on opposite sides of the boards for giving lateral support to the same, and spacers 3 interposed between the boards.

The stakes are arranged in opposing pairs, and the spacers are preferably alined with the stakes.

The wire i, which is cut to the proper length, is guided about the stakes in the manner shown. The central portion is placed about one stake, and the end portions are passed through holes 5 in one of the boards and are then made to cross between the boards and are passed through corresponding holes 6 in the other board, to emerge from the latter adjacent opposite sides'of the second stake to present loose ends following the sides of the latter stake and projecting beyond the outer edge thereof.

, My wire tightener comprises in the form shown in Figure 1, a yoke l and a screw 8 threaded through the top thereof.

The yoke "I may be made in any suitable form and is here shown as a strap of metal bent into semi-cylindrical shape and having two radial flanges 9 adapted to bear against the edge of the stake, the flanges being preferably formed with pointed prongs l0 adapted to anchor in the stake material.

The screw 8 extends through the yoke perpen dicularly to the stake and is threaded, in the form shown in Figure 1, through a hub I l secured upon the yoke, the outer end of the screw having a suitable handle l2. The inner end of the screw terminates in a square head facing the stake and adapted to have the ends of the wire anchored thereto.

The details of the head are illustrated in Figures 2, 3 and 4, from which it appears that the head is in the form of a fairly heavy, substantially square block having its outer face 13 arranged opposite the stake and having two grooves l4 therein, the grooves extending from the center in opposite directions and having inclined bottoms so as to gain in depth toward the edges of the block. The grooves are adapted to receive the two projecting ends of the wire after the latter have been crossed over the near face of the stake.

Two additional grooves 15 are cut into the block vertically from the upper edge to intersect the first pair of grooves at their outer ends and these grooves have cams I'B mounted therein on pivots l1, each cam comprising a handle it projecting normally above the block in substantially vertical position and a cam section i9 normally clearing the wire disposed in the lower groove, but adapted to be clamped upon the same when the handle is thrust outward.

The wire-engaging face of the cam is preferably serrated for a better grip upon the wire, as shown. The two grooves 55 are arranged at a slight forward angle with respect to the rear face 13, so as to allow the operatorto clampthe cams down on the wires with a slight forward pull, that is, away from the form.

The operation of the device thus far described, is as follows:

After crossing the projecting ends of the wire, the operator anchors the yoke tothe stake, with the head of the screw facing the .wires,.guides-.the1

two wire ends into the grooves l4 and clamps the same in place by pulling down on the cam handles.

He then turns the screw handle H2 in the proper direction which causes the head is to pull away from the stake and to turn at the same time, placing'the wire under tension throughout the length thereof and at the same time twisting the wires about one another.

In the form shown in FigureZ, a modified actuating means for the screw is shown. Instead of being threaded into the yoke directly, as in Figure' 1, the screw is threaded into a nut 29 bearing onthe outer face of the yoke 'i and being revolvable in a bushing 2! secured upon the yoke.

The nut ZEJ-is held against outward movement bya shoulder 22 riding in a registering annular groove in the-bushing. The nut is turned by means of a handle 23.

In' this form, when the nut is turnedin the proper direction, it first exerts outward pull on the head l3 until the entire wire is placed under a certain degree of tension. Thereafter, the-resistance tooutward pull becomes sufiiciently strong to cause the head it to revolve with the nut and to thereby twist the ends ofthe wire about one another.

Due to the fact that the screw and the nut are both revolvable with respect to the bushing 2|, endwise motion will substantially cease when rotary motion of the head commences;

In the form shown in Figure 5, a still different effect is obtained:

In this form, the screw 8 is threaded directly into the bushing 26 on the yoke l, but is revolvable in the head by means of a shoulder 25 ridingin a registering recess in the head 28, a retainer and dirt sealf beingprovided at 2'5. I provide a transverse slot 28 111 the screw stem; a transverse pin 29' movable in the slot, and a double Acme thread 3% in the inside of the head, the ends of the pin engaging in the Acme thread.

In this form, the head is preferably formed with a reduced extension 3i to accommodate the length of the Acme thread. The two ends of the wire maybe secured upon the head'in the same manner as previously described, ,by suitably mod-- ifying the shape of the head, or'by means of two holes32'through which the ends of the wire may be guided for fastening upon the head.

In the above form, with the pin in a midway position, when the screw is turned, the. head will first recedewith. thescrew, without turning. In the meantime, the pin 29, will ride inthe slot-=28 until it reaches one endof the slot. Then relative rotary motion between the head: and the screw ceases, and the two turn as a unity to=-produce'a twisting efiect.

But, even then the headkeeps;re ceding: with the screw, so that in'this' construction, the wire is first tensioned until the pin reachesthe endiof the; slot, while thereafter it is subjected .to arcome bination twistingandtensioning movement; The

degree of initial tensioning movement can be regulated by adjustment of the pin in the slot.

I claim:

1. A tightener for a tie wire having ends straddling astake and projecting, beyond an edge thereof, the tightener comprising a yoke braced against the stake, a head member having means for securing the wire ends thereon and a threaded element co-operable with the yoke in advancing. the element, the latter being anchored to the head with limited freedom of revolving motion.

2 In a wire. tightener of the character described,,a,screw head having a groove in its outer face for receiving a .wire therein and having a second groove intersecting the first groove and a cam operable inthe second groove for anchoring the wire-in the first groove.

3;- In a wire tightener of the character described, a screw head having two grooves in: its

outer-face extendingfrom a central portion in opposite directions and increasing. in depthto.- ward the edges and having a second pair of grooves intersecting'th'e former, the first pair of grooves being adapted to accommodate a pair of intersecting Wirestherein and the second pair of grooves having cam members operable for looking the wires in the first' pair of'grooves.

l AZ tightener for a tie wire having endsstraddling a stake and projecting beyond the edge thereof, the tightener comprising a yoke-braced against the stake,- a head member having means for securing the wire ends-thereon, andthreaded means bearing on the yoke for retractingv the head, thelatter means including a threaded actuating member having: a limited freedom of revolving motion with respect to the head so-as to cause the latter to retract through a certain distance without turning for tensioningthe wireandmeans forautomatically locking the actuating: member with respect to-the head after a predetermined amount of retraction to cause the head to turn with the'actuatingmember for twisting the wire ends.

5. Atightener for: a-tie wire having-ends-straw dling a stake and projecting beyond the. edge thereof;" the tightener comprising ayoke. braced against the stake, a head member having'means for securing the wire ends thereon, and threaded means bearingon the yoke for retracting the head, the latter-'mean'siincluding athreaded actu ating member. having a limited freedom of revolving motion with-respectto the headsoas to cause the latter to retract" through a'certain dis tance withou-t turningfor tensioning the wire and means for. automatically locking: the actuating member with respect to the head after a pred'ee termined: amount: of retraction to cause. the head to turn-with the actuating "member for-twisting the wire ends, the locking meansbeing operable foradjustment. for difierentrdistances of the first-mentioned retracting. movement.

BURT J BRADLEY;

REFERENCE 5 CITED The following references" are ofrecordinthe file of this patent:

UNITED STATES" PATENTS Number Name Date 605,930 Stauffer- June 21, 1898 1,045,994 Mad'son et al. Dec. 3, 1912 1,336,159" Rice; Apr. 6, 1920 1,494,413 Caldarelli May'ZO, 1924 1';504;647" Scott Aug; 12} I924

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