US2329906A - Triangulated framework - Google Patents

Description

- Sept. 21, 1943.

c. E. INGLIS 2,329,906

ANGULATED FRAMEWORK Filed March 26, 1941 4 Sheets-Sheet l Sept. 21, 1943.

c. E. INGLIS TRIANGULATED FRAMEWORK Filed March 26, 1941 4' Sheets-Sheet 2 II IVII/Il/IJ IX X msw mfi u Sept. 21, 1943. c. E. mus 2,329,906

TR IANGULATED FRAMEWORK r Filed March 26, 1941 4 Sheets-Sheet 3 zzmsn ag a fig Us Sept. 21, 1943. c. E. INGLIS 2,329,906

TRIANGULATED FRAMEWORK fiueo-g 5 425 1 tional ir'dis'" are built upiin s 'to complete the bridge a chines; Euw

S n r 1 9 ted.

- This" inventsi1 imam-es to" ma h-fl re works which are eapab eef general? apphcat n to the umerene of loadsbu't whieliare parti larl 'suite'd toithe construction if The" inve'ntion has for triangulated riamewai a hi easili recteilfahd whicthe s'ubpo'rting ofvaryih loads girder;i r1 acbordan fwith-theif1vnti constructed fem-fem m] j A gether by'jun'ctior boxes to mrm the. upper and lower teams and the web-b races 'anc l toprovide additional load carryin a jaeity add'itional p11 and juficti'ori-bokesiareprovitiedsoftha a im-i jr subplehier'itary g'irderiorfgirtlis rhay' ltuq irif's'itu alorissidethemain "girder a A hectcl threwithf th i e iils insifih brid iifi l f?! constructed is then launched ross the span to be'bridge'd ahgl-subsequeritl or'ln cre-addif 1 constructed girders and fjciohffiecte' order that the carrying ca acity of th be'i creased;

The invention also extends to the prpvi m e .iu io -b xes ri e le i' tubes to the other fea ures olfijcon ruotio "e ter described; or ir dicated, f In the accompanying are n s.. I Figure 1 vis an oisom-etricjliew otapprt en of bridge v con'struct'ed} iri (aceei dafice with t vention, 3, 5

Figure Zis a.fragmentary viewlshow gr I elevationythe plates provided ofty-ing together} the laterally adjacent tubes,

Qjl igure Bis an end viewof Eigu 1 !-.Figure 4 is-anveneview of ab dgep w ti ozi accordingto the invention invol irig-a tr tube assembly, Figure 5- is a front eleyational viewjof: a 1ower junction-box,'-v shown securedato its latter beingginsection;ea. F W71? .;Figur,er:j6 is'an'end v w Section? 1"1': "Ti? H" 1.11"? ;Figur'e "7 isiapl'anview oidth stirrup plate ernployed-for:securingto the .tr'ans-omsuch' iadditional lower -juricti-onf-rb'oxes a as :may be required .ter' the rnfain girder-s have been'erected', 1 f

' Figure 8 is a junction-box,

- *Figure 9 ure'8; 1 I t Figure 10 is fra mentary view partly in secion'bf a tubend joir'iti- 7 fi'ohtelevatiorial View of an upper Figure 11 shows oneofthethrough bolts em ployed for securing the adjacent junction-boxes together and provided with a single tapered lo-' catingplug whereby the bolt is applicable toa two-'tubei'girder as illustrated Figure 1, the

plug being *shownin section'andthe bolt being brokenaway for ease of illustration,

f Figure 12 is asimilar View to Figure 11 but equipped withtwo locating 'plug sothat'the' bolt is "applicable to a three-tubefgirderas illustrated i p lk :1; 'i o Figure -13 is a froritelevaftional viewof a modi fied form *of base junction-box suitable for use whenit' 'isdsired' that in the case-of a brid e cor struetiomfor example, there should be an inclined trackwayleadingto the bridge proper,

: I'Figure 14'is a view" looking iri the direction of the-arrow A of Figure 13 with the-male'part of space to be bridged'and betweenwhich the bridgeway 2 is carriedso' as to he-supported'by the irders, each of which is built up fromsimilar steel' tubes' united together iii the form of a Warren girder having the tube'elements thereof disposedjinavertical plane.

'Theindividual tubeielem'ents are connected at i som's-Band have four tubular sockets l, 7, 1a, a

la; while the-upper junction boXes may have six tubular sockets f8; 1 8 8a, 6a, 8b. 8b; inclined to each otherj'at an angle of The tubular sock ets"1 of' each base *b'o-x 'casting are in line'with is a section on the' li e" l 5 -l,5of

one another and receive the adjacent horizontal tubes forming the bottom boom 9 (Figure 1) of the girder while the tubular sockets 8 of each upper box-casting are also in line with one another to receive the adjacent horizontal tubes forming the top boom of the girders.

The two socketsjl a in each base junction-box and the two soekets 8a: in each upper junctionbox serve to receive the ends of those tubes which form the Web braces ll (Figure 1) of the girders while the two additional sockets 8b in the upper boxes may serve to receive the lowerends of. a

further series of tubes forming upwardly execonomical manner.

The individual tubes are connected to theirrespective junction-boxes by means of a loose pin joint which includes a nut l2 (Figure 10) threaded on tothe tube end .andadapted topress against a bearing surface l4 (Figuresyfivandfi) our the. junction-box: to take up the back-lash when the nut is tightened. For this purposethere isfitted toeach end ofieach tube atongue element 55 having an externally-screw-threaded end portion 56, whiclris-secured within the end ofthe tube by being engaged w-ithan internally screw-threadedportion I3- thereof: and. which tongue is'provided with a-transverse-slot l belongated: in the direction oi the longitudinal axis of the tube, Eachend portionof the-tube containing the interior screw -threadedportion is also screwthreaded1 on! the outside to receive thereon the nut iZiandalOosepin: I ia isiprovided for use in association with each joint. Each socket in the junction-boxes is larger-than the tongue so that the. latter can readily be positioned therein andwhen thiswhas been ac,- complishedsuch that theyslot; inthe tongue is disposed opposite openings l 8 in the. wallssof: the socket (which openings. are also. larger. than: the pin) thejoint pin llae isjplaced-in positionsoas to extend transversely; through the slot; The final joint is made by tightening'gthe nutiso that tlze slaclrness of the pin,- due to the. elongated slot in the tongue and the enlarged openingsin the junction-box, is taken; up and the; tube :I is fixed in position as.- well-as being fixedxrigidly in its correct. direction relatively to the1junctiont is intendedthat the bridge should be con structed on landin skeleton formiby. apair'. of tubular girders as above described being assembledand secured-to the transverse joists or tran somswhich serve to receive the floor of the bridge and that when this-skeleton'bridge,that is the bridge consisting ofthe main or outside girders land: the transoms; 6' as illustrated in Figures 1 and 4, has been launched across the span to bebridged if, further strength is required shall beprovidediby-one or. more addi tionalrgirders- 2% being built-up in situ alongside the preformed girders of theskeleton bridge; each additional girder being also composed: of similar tubesand junction-boxessimilar to those already described. In this way the important advantage. m obtainedthat thefinal'bridge may be made to .withstand.heavy; loads without, however, the need for increasing the launching weight. The bridge as illustrated in Figure 1 is of double-tube formation whereas the bridge according to Figure 4 is triple-tubed and as the 5 upper and lower junction-boxes are similar throughout these have been given the same references.

The junction-boxes providd to form thebase junction-boxes of 'the tubes of the girders to be built up in situ alongside the main girders are, however, of modified construction and permit of these boxes being placed loosely upon their supporting joists or transoms 6 and secured thereto during the construction of the supplementary i5girder'or1after the same has been completed.

This is achieved by each such box being provided with a pair of laterally spaced bolts l9 pivoted to the, base of the box so as to depend therefrom and adapted to pass through openings at the ends of a transverse stirrup plate 2! passed beneaththe base of the joist or transomsothat the bolts lie upon. opposite sides of the latter, the-free ends of: the bolts being screw-threaded to receivesecuring nuts22 for pulling the box 5 hard downagainst the top flange 2010f the ioist.

Conveniently the said openingsmay consist of a bore 23. through which the corresponding bolt is introduced as the box islowered intovposition upon the joist and an open-ended slot-.24 into which the other bolt can-be moved by angular movement thereof, the arrangement permitting of a fastening ofthe box by the securingof the nuts on the bolt which ispassed through the said bore (there being two nuts consisting of the one 22 secured upon thebolt beneath. the said stirrup plate and a lock nut 25: secured. upon the bolt above the stirrup plate,;the-latter;'beln8 drawn into close contact-with the base of the joist whenthe'nuts are tightened) and of-a final 40 securing of the box in positionby theother bolt being secured within. the slot in the plate. The arrangement. enables two, three ortevenmore girders to be built up insitu alongside-each main girder to providesuch increased carrying ca pacity as may. be required'while'thecomplete elasticityof the system permits of the strengthen.- ing of the main girders to be carriedout to. a varying extent lengthwise thereof by, for-example, each girder being made of double-tube form in the end portions thereof. and of. triple-tube form in the centre portion. r

The base junction-boxes employed for the main and the supplementary girders are-identical ex.- cept for the provision of the bolts I9.and associated parts for the junction-boxes of the supplementary, girders, and accordingly. Figure is relied upon as illustrating both the base junctionbox employed for the main girders and alsofor the supplementary girders. This enables a uniform construction of all the base junction-boxes to be adopted since, when required .for useto form a supplementary girder, it is only necessary pp y the bolts l9 to the'lugs 26 (Figure 4) ghich depend from the base of each-junction- Conical bosses 28a may beprov'ided on the stlr rup plates at the slotted ends thereof for engagement with conical recesses in thenuts to prevent the bolts engaged with'the slotsfrom escaping therefrom when the nuts are tightened;

Since the addedgirders are identical inform to the girders originallyerected, when the lower junction-boxes are pulledv down-bythe bolts and stirrup plates to make close contact with the transoms, the deflections of the girders thus axes of the tubes at their ends are constrained to lie at right angles to the axes of the bolts coupling together adjacent upper and lower junction-boxes and has the effect of greatly increasing the lateral stiffness of the girder when doubleor triple-tubed.

A suitable form of through bolt is illustrated in Figures 11 and 12 wherein the bolt 28 is formed to pass through the central openings 29 in the base junction-boxes and through openings 29a in the upper boxes 4 and has screw-threaded ends 30 which project beyond the outer faces of the junction-boxes and serve to receive the nuts 3| which are tightened upon these faces and to force adjacent junction boxes to register coaxially tapered bosses 32 are provided.

The through bolt illustrated in Figure 11 is suitable for application to a two-tube girder as illustrated in Figure 1 and has secured thereto a plug 33 having a tapered end 34 and opposite end portion 35 Which is adapted to enter openings 29 or 29a of the junction boxes to align said boxes as the nuts 3| are tightened.

The through bolt illustrated in Figure 12 is suitable for application to a three-tube girder as illustrated in Figure 4 and the through bolt in this case is provided with two plugs 33a slidable upon the bolt and provided with coaxial sleeves 31 which, at their outer end, are engaged by the nuts 31 when the latter are tightened upon the bolt and the correct location of which upon the bolt is ensured by the presence of the flanges 38 upon the latter whereby as the nuts are tightened, the tapered ends 34a of the plugs will firmly engage within the central opening 29 or 29a of the central junction-box while the outer junction-boxes will be aligned by the base portions 35a of the plugs fitting in openings 29 or 29a.

The overall diameter of the plugs is such as will permit the bolt and the plugs to be passed freely through the openings 29 of the junctionboxes to be tied thereby after which the nuts 3! are secured in position upon the bolt and tightened to complete the tie.

To provide additional lateral rigidity or strength the transversely adjacent tubes of the main and supplementary girders may be connected together by plates 39 (Figures 2 and 3) secured transversely across the tubes intermediate the ends thereof. These plates are'ccnvenientlyof skeleton and channel form and are secured one upon opposite sides of the tubes so that the channels thereof face inwards and partly embrace the tubes of the flanges by forming the. channels with recesses to receive the tubes, the attachment of the pairs of plates to the various tubes being effected by bolts 40 passed through openings in the plates so as to extend in the direction of the girders and to which bolts securing 7 nuts 4| are applied at the end portions thereof.

Figures 13 to 17 illustrate a modified form of base junction-box suitable for use when an inclined approach to a bridge is required in which case the end base junction-boxes of each girder are of this modified form and each comprise a fixed female part 41 and a male part 48 which is pivotally mounted upon the fixed part so as to be capable of being swung outwards with respect to the latter according to the inclination required. In such case the upper booms of the girders will be discontinued between the bridge proper and the inclined gangway. The male junction part is formed with a fork in the form of a pair of spaced lugs 49 adapted to be introduced into a bearing block 50 on the female part so as to be positioned between two axially spaced ring plates 5| therein and formed with central openings 52 for receiving a pivot pin or plug.

I claim: I i

1. A triangulated framework structure comprising in combination a main girder composed of similar tubes forming the upper and lower booms and the web braces, junction-boxes connecting the tubes with each other, a supplementary girder composed also of similar tubes and junction-boxes disposed to lie alongside the main girder, transverse transoms spaced longitudinally of the girders and common to and connected with the base junction-boxes of both girders, and means independent of said transoms connecting the adjacent junction-boxes of both girders. j

2. A triangulated framework structure as claimed in claim 1, wherein the junction-boxes are formed with central openings and through bolts are provided adapted to be passed one through each aligned series of openings of the laterally adjacent junction-boxes of the severa girders to connect the same together.

3. A triangulated framework structure as claimed in claim 1, wherein bolts passing through the junction-boxes are provided for securing the adjacent junction-boxes together, drift plugs on said bolts serving to obtain the proper coaxial reg.- istration of the junction-boxes and equal distribution of the stresses throughout the adjoining tube members, the drift plugs being spaced axially along the bolt and having tapered ends engageable within the central opening of the junction-boxes.

4. A triangulated framework structure comprising in combination a main girder composed of similar tubes forming the upper and lower booms and the web braces, junction-boxes connecting the tubes with each other, a supplementary girder composed also of similar tubes and junction-boxes disposed to lie alongside the main girder, transverse transoms spaced longi

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