US2614801A

US2614801A - Wire holding and prestressing device

Info

Publication number: US2614801A
Application number: US175925A
Authority: US
Inventors: Mazzei Oswald
Original assignee: AIRCRAFT HARDWARE Manufacturing CO Inc
Current assignee: AIRCRAFT HARDWARE Manufacturing Co Inc
Priority date: 1950-07-26
Filing date: 1950-07-26
Publication date: 1952-10-21
Anticipated expiration: 1969-10-21

Description

Oct. 2l, 1952 o. MAzzEl '2,614,801

WIRE HOLDING AND PREsTREssING DEVICE Filed July 26. 1950 IN V EN TOR. OSW/1L D MAzzs/ @fusi/v TFA/wmv f//s AroRA/.EY

Patented Oct. 2l, 1952 practice? in applyingreinforcing' Wireto' concrete pouringfo`1msto initially thread one" or hoth ends of the. reinforcing wire so that" when" the wi'eis arrangedin theh pouring form, nuts may be appliedtliereto' andusedto-draw the' wire tautl This priorartlmeth'o'dlof^`tigliteningf thereinfo'rce ingA Wireinvolires time' and labor in'rst accu,-

rately measuring;r and cutting the Wire into appropriete lengths, in then i applving', threaded.' end sections to eachwire length, andnallyfinapply.- y

i'ng'f` washers. and nutsito'. draw the Wire taut',A The.. iinprovediWirey holding., andl prestr-e'ssing` dei/ice. constructed. in.. accordance. with... this.. in i(entiornmay4 comprise. a i sturdy easing. Whichtis dsigned to telescope. over the, projecting end` section.. ofthe` reinforcing., wires'. Thecasingf, has a; foot section .atl one, endl thereof.` dsignedoto. beV removably secured.` to.. the. endwall` i of.' the`^` pouringvlform through Which=the endl section of. the reinforcing wire projects. "The casing, enoloses a. reciprocable block presentingla.. pair.. of., spaced legs. The` spaced legs have. a.hngedldgrand pair' of space'd stud pins positioned" therebetween Whioliare operable toxsecurel'y' gripj the end .seetion' of' the; reinforcing wire whenv threaded" between the" dog.' and the" spaced: studi pins.' The recibrocable block hasw a" tubular shaftsecti'on extending from onev end thereof *throu'gh' which the reinforcing wire'i's threaded; the shaft" seetion projecting through a= bore in a:lieacll"section provid'dl'atl the otherE endJ of th'ecasi'ng: The shaft* section is extern'ailx'lffthreadedtc and carries'a nutidesiened`` toseat againstithe atendof the head section of'l the casing;` so i that '-When the` nut isemanpul'ated; axial?movement*'willheiinpartetl teitleiliilozlvifthinthe?casing?A 'llhe` casing is' alsoprovidedwitI-ia, tapered cani plate.- seclured t'o s the interiori surfieeJ` thereof lengths which cooperates-r with: the'- heer i @tithe i dog-"tb: f

2 tnerehwdepressftnefdbgr andzbend: the reinforcing Wire: UetWe'en the',` spfatoedY stud?. pins:Y and thereby form-i all griinping; therein whenv the exterior nllt isf." initially manipulated When; the;V nut S Irther manipulated-gime' blocka is furtherrdrawn toward tnelheadLsectiom of theflcasingto thereby` draw? thereinforoing wire` to th'e: desired: tautness. i

`By:the'nse ofi thisf` improved wire hoidingf and prestressingdevi'ce; tneafpriozrartitimerconsuming practice:- on accorateiyr measuring; cutting.y and subsequent? threading? the tends ofitheireinforcing wire? te4 ac'eommouate washersannuts; mays' be entirely," elim-mated.. i t

improved@ wire:- hoiiingfl` anni priestr'essing" device which inwayfbevrepeatediif usedtovholdl andrpre'- they feetive` presi;rese-ingy of' their reinforcing wire with accornpanyingl substantial' savings time? and labor;

\ partjsriiiitheseverallviewstand?inrwnich;1

Figi lfii'sfasideteievatienaiview of evconcrete peu-ring? form?. throiighz which* a plurality ofrein'iifrfcingi` Wireshave",Y beenstrung; andi which are held-ltaliti and prestfess'e'c'i by? the:` application thereto offthe improvedlwirezoldingand prestressing devices@ made-in aneord'anceiwith!` this l inventiom.

tha-'concrete pouring form with th'ewirehold#` beforetiie-wiresha's been stretched.

"Figi 5# isff another longitdinal cross=seetiona1 vieveoffthe-wirefi1io1dihg aridfprestressing device applied to the end wall of the pouring form and as the same would appear after the wire threaded therethrough has been prestressed.

Fig. 6 is a transverse cross-sectional view of the device as the same would appear when viewed in the direction of the arrows 6--6 of Fig. 5.

Fig. '7 is a transverse cross-sectional View of the device illustrating the position of the prestressed wire when the device has been rotated through 90 to thereby permit removal of the device from the wire.

Fig. 8 is a plan view of the wire holding block and associated wire gripping dog; and

Fig. 9 is a fragmentary elevational view of a concrete pouring form in which one end of thel reinforcing wire is bent over the adjacent end wall of the form so that only one wire holding and prestressing device attached to the other end of the wire need be employed to prestress the wire.

Wire holdingY and prestressingdevices oon-r structed in accordance with this invention are designed for use in connection with concrete pouring forms, which as shown for purposes of illustration in Figs. 1, 2 and 8, may be saidl to generally comprise a pair of spaced end walls a connected by side walls b. .The several lengths of reinforcing wire w extend lengthwise through the pouring form so as rto become embedded in the concrete when the forms are lled with iiuid concrete. The end sections w. of the wire lengths w project through the end walls a of the pouring forms and the wire holding and prestressing devices A of this invention are designed to be removablyattached to the projecting end sections w of the wire lengths .and to seat against the adjacent end wall a of the pouring form.

This improved device for holding and prestressing concrete reinforcing wire generally comprises a casing yI which may be made of stamped or cast metal. The casing I0 may have a circular or polygonal interior bore II which is open at the base end thereof and is provided with a head section I2 at the other end thereof, as shown in Figs. 3 and 5. The base end of the casing is provided with an outwardly flared foot section I3 designed to seat against the end wall a of the pouring form. The foot section I3 may be provided with a plurality of spaced holes I4 through which nails or like securing means c may be inserted to temporarily secure the casing I0 to the end wall a of thev pouring form.

A block I5 is designed tc reciprocate within the bore II of the casing and may be generally vU- shaped in configuration, presenting a head portion I6 having a pair of spaced legs I7 extending therefrom in the direction of the base end of the casing I6. The reciprocating block I5 has a tubular shaft section I8 extending from the head portion I6 thereof. The bore I9 in the tubular stem section I6. is of ample diameter to permit various sizes of reinforcing wire to be threaded therethrough. The shaft section I6 extends through a conforming bore I2 in the head section I2 of the casing I0. A sturdy manipulating nut threads over the heavy external threads 2| which encircle the stem section I8, with the base of the nut 26 designed to seat against the flat end face 22 of the head section I2 of the casing I0.

Wire gripping means associated with the leg portions I8 of the reciprocable block I5 is provided to firmly and tenaciously grip the end section w of the reinforcing wire w threaded between the leg portions I? andthrough the bore I9 in the stem section I8. The wire gripping means comprises a pair of spaced stud pins 25 which are secured to the leg portions I'I and span the space therebetween, as shown in Figs. 3, 5 and 8. The stud pins 25 are so located that the end section w of the reinforcing wire will initially lightly rest thereon when the wire end section is threaded through the bore I9 of the stem section i8. A wire gripping dog 26 is positioned directly above the wire supporting studs 25 and is hingedly mounted at one end thereof between the spaced leg portions I'! of the reciprocable block i5 by a hinge pin. 2 which extends between and is secured to the special leg portions I'I of the block I5. The lower edge of the dog 26 is provided with a nose portion 23 formed integrally therewith which is located so that it may be swung between the spaced wire supporting studs 25.

When the reciprocable block I5 is in the retracted position shown in Fig. 3, the Wire gripping dog 26 is free to swing upwardly so that the straight endfsection-w of the wire can be strung between the wire supporting studs 25 and the nose portion 28 of the dog 26 with the heel portion 29 of the dog adjacent the interior surface of the casing bore I I. However, means are provided to forcibly swing the dog 26 downwardly so that the nose portion 2B will project between the wire supporting studs 25 to thereby form a kink w in the wire and thus ensure a rm grip on the wire when the reciprocable block I5 is drawn towards the head section i2 of the casing. The means for manipulating the dog 26 into gripping engagement with the Wire comprises a cam plate 30 which may be secured as by screws 3l to the inner surface of the casing I0 directly above the pivotally mounted dog 26. The cam plate 35 has a tapered camming surface 32against which the heel portion 29 of the gripping dog may cam when the reciprocable block I5 is drawn toward the head section I2 of the casing I0.

By an appropriate rotation of the manipulating nut 26, the reciprocable block I5 may be drawn toward the head section I2 of the casing to thereby drag the heelportion 29 of the gripping dog 26 longitudinally along the tapered camming surface 32 of the cam plate 30 in a manner to forcibly drive the nose portion 28 thereof against that portion of the reinforcing wire which spans thel wire supporting stud 25, to thereby form a decided bend or kink in the stud spanning portion w of the wire, as illustrated in Fig. 5. Continued tightening manipulation of the nut 20 serves; to draw the reinforcing wire taut and maintain the reinforcing wire in the desired taut and prestressed condition during pouring of the concrete into the pouring form and hardening thereof to the desired hardness.

Torensure smooth reciprocating movement of the block I5 within the casing I6, a guide plate 35 is provided which is positioned between the leg portionsr Il of the block I5 Aand is secured as by screws 36 to the adjacent inside face of the casing. Il). The side edges 3l of the guide plate 35 `have bearing conta-ct with the inside faces of the leg portions il of the block I5 and thus prevent rotative movement of the block I5 within the casing IQ and ensure smooth reciprocating movement thereof. The guide plate 35 additionally serves as a stop means to limit the retracting movement ofthe block I5. It will be noted that when the reciprocable block I5 is in its fully retracted position as indicated in Fig. 3, the inside face of the head portion I6 of the block I5 will abut against the end 38 of the guide plate 35 to thereby also limit the retracted positioxr tithe block; I E? 'Ihguide platei 35'\'-as-` well asith leg-portions II ofi the blocks'A I 5;i are-off' suf?- fielen` length; sq-jthati the side'y "edgesf 311 V*ofi the guidirpllaitei35iarey in constant guiding contact with the leg portions.Ilwhentheblock has been advanced to itsm'aximum Wiretightening position.; i i

This improved device can beeasilylr andsquickly detached fnomv theend?seoticmiwf-4 of; the rein forcingwire and removed from the end Walla ofthelf-pouring form by rstiloosening the manipultingfnutil; thenswithdrawingjthe nailsc; from the;V foot* section I3* of" the casl'gd, andix theta upon rotating the" casing I'Il* through anL angle of approximately 90 as shown in Fig. 7 Rotation of the casing I through an angle of 90 operates to likewise rotate the gripping dog 26 4and wire supporting studs 25 through a corresponding angle, so that the nose portion 28 of the dog 26 will swing out of thekink depression w" in the wire and lie against one of the relatively straight side faces thereof, and with the wire supporting studs 25 positioned adjacent the other relatively straight side face of the wire. With the .gripping dog 26 and Wire supporting studs 25 thus located, the entire casing ID and its associated reciprocable block I5 can be drawn off from the projecting end section w of the reinforcing wire w.

This improved wire holding and prestressing device may be sturdily constructed from a relatively few and simple parts at relatively low cost, and can easily and quickly be attached and detached to various sizes of concrete reinforcing wire. These improved devices provide a convenient and practical accessory to mechanics er1- gaged in building concrete structures which can be used to effect substantial savings in time and labor in holding, prestressing and maintaining taut the reinforcing wires in concrete forms.

While certain novel features of this invention have been disclosed hereto, and are pointed out in the claims, it will be understood that various omissions, substitutions, and changes may be made by those skilled in the art without departing from the spirit of this invention.

What I claim is:

1. An improved device designed to prestress and maintain reinforcing wire taut comprising a casing, a head section at one end of said casing, wire holding means reciprocable in said casing, a shaft Aportion extending from said wire holding means and projecting from the head section of said casing, and take up means associated with siad shaft portion coacting with said head section to manipulate said wire holding means within said casing, said wire holding means including a reciprocable block, a wire gripping dog pivotally mounted on said block, spaced studs designed to support an end section of the wire extending into said casing; and cam means within said casing operative to manipulate said dog into gripping engagement with the stud spanning portion of the wire end section.

`2. An improved wire` holding and prestressing device including, a casing designed to receive an end section of the wire, said casing having a foot section at one end thereof designed to seat against the wall of a concrete pouring form and a head section at the other end thereof, a block reciprocable in said casing, a shaft portion extending from said block through the head section of said casing, means associated with said shaft portion coacting with the head section of said casing for reciprocating? saidi block; spacediI studsmountc om said=blockfiprovidingf support, for tti-@endl secs tion of thefwirei threadedi through saidlcasing; a wire-1 gripping-- dog pivotajllymounted?on:4 saidv block, afy canrmember iixedi to 1- the==interiorof said casingand extending#longitudinallyfthereof; said dog having ai. heel-i portion i designedi tok ride=` over said?camfmemberiandfa noseporti'on designed? to depress the Studispann-ing portion of-{thefwirelend section to-form ai kinlr thereinfwhen"` saidbloclcisr dravvrnn towardsVA the head" section ofi 'saidi `casing by'saidimanipulatingmeans` g improved.I wireqholdingfn afrid` prestressing deviceeincluding; acasing-designed toi-receive an end section of a wire, said casing having a foot section at one end thereof designed to seat against the wall of a concrete pouring form and a head section at the other end thereof, a block reciprocable in said ca-sing, said block having a head portion and a pair of spaced legs extending toward the foot section of said casing, a shaft portion extending from the head portion of said block through` the head section of said casing. means cooperating with said shaft portion and said head section for reciprocating said block within said casing, spaced studs extending between the legs of said block providing support for the end section of the wire threaded through said casing, a wire gripping dog pivotally mounted between said legs, and a cam plate fixed to the interiorof said casing and extending longitudinally thereof, said dog havingr a heel portion designed to ride over said Icam plate and a nose portion designed to depress the stud spanning portion of the wire end section to form a kink therein when said block is drawn towards the head section of said casing by said manipulating means. l

4. An improved wire holding and prestressing device including, a casing having a foot section at one end thereof designed to seat against the Wall of a concrete pouring form, a head section at the other end of said casing, a block reciprocable in said casing, an externally threaded tu bular shaft portion extending from one end of said block through the head section of said casing, said casing `and tubular shaft section being designed to receive an end section of a wire threaded therethrough, a manipulating nut in threaded engagement with said tubular shaft portion and designed to seat against the end face of said head section, spaced studs associated with said block providing support for the end section of the Wire threaded through said casing, a Wire gripping dog pivotally mounted on said block, a vcam member fixed within said casing and extending longitudinally thereof, said dog having a heel portion designed to ride over said cam member and a nose portion designed to de press the stud spanning portion of the wire end section to form a kink therein when said' block is drawn towards the head section of said casing by said manipulating nut.

5. An improved wire holding and prestressing device including, a casing having a foot section at one end thereof designed to seat against the wall of a concrete pouring form, a head section at the other end of said casing, a block reciprocable in said casing, said block having a head portion and a pair of spaced legs extending toward the foot section of said casing, an externally threaded tubular shaft portion extending from the head portion of said block through tubular shaft portion being designed to receive 26. lef-1,80 1.

an end seetion of awire threaded therethrough, a manipulating nut in threaded engagement With said,A tubular shaft portion and designed to seat against the end face of said head section, spaced studs extending between the legs of said block providing support for the end section of the Wire threaded through said easing, a Wire gripping dog pivotaliy mounted between said legs, a cam plate xed to the interior of said casing and extending longitudinally thereof, said dog having a heel portion designed to ride over lsaid cam plate and a nose portion designed to depress the stud spanning. portion of the `Wire end section torform a kink therein when said block is drawn towards 83 the head section of said casing bysaid manipulating nut, andmeans Within said casing for-guidf ing the reciprocable movement of said-block.` OSWALD MAZZEI.

REFERENCES CITED The following references are of record inthe le of this :patent: l

r UNITED STATES PATENTS Number Name Date` i 1,186,554 Crisenberry -June.13, 191,6 2,303,394 Schorer Dec. 1, 1942 2,328,033 SChOrei Aug. 31, 1943