US1151657A - Bascule-bridge. - Google Patents

Description

T. E. BROWN.

BASCULE BRIDGE.

APPLICATION ULEB MAH.20.1913.

Patented Aug. 31, 1915.

3 SHEETS-'SHEET l.

T. E. BROWN.

l BASCULE BRIDGE. APPLICATION FILED MAR. 20. 1913.

1,151,657. Patented Aug. 31,1915.

3 SHEETS-S T. E. BROWN.

BASCULE BRIDGE.

APPLICATION FILED MAR.20.1913.

3 SHEETS-SHET 3.

Patented Aug. 31, 1915.

l To all inkom it may concern THOMAS E. BROWN, F NEW YORK, N. Y.

' BAscULE-BRIDGE,

Be it known that I, THOMAS E. BROWN, a

. citizen ofthe United States, and a resident windin of the borough of Manhattan, in the county of New York and State of New York, have invented certain new and useful Improvements in Bascule-Bridges, of 'which the following is a specification. l t

This invention relates to improvements in bascule bridges, of the general kind de.-v

scribed in my United States Letters Patent, numbered 590,787 and dated September 28th, 1897. l

1t is the especial purpose of the present invention to simplify and cheapen the construction and operation of such bridges, and particularly to efect the raising and lowering of the bridge with the lminimum expenditure of power, and the secure holding of the bridge in its raised and ii its lowere position merely by means of simply constructed and operated cables, weights and hydrau io rams or other costly machinery for eii'ecting the movements of the bridge and for securely `holding the bridge in 'its positions is obviated.

The present invention relates to bridges of that class wherein a counterweight is so connected with the bridge by rigging that the pull of the counterweight on the bridge automatically varies exactly as the turning moment of-the bridge about its pivot varies, and thus the counter-Weight automatically balances the bridge in all positions, notwithstanding that the turning moment of the bridge varies frm oneposition to another of the bridge. Obviously 4a bridge so balanced with a single counter-weight connection, and when not in a vertical or nearly vertical position, can be raised or lowered simply by exerting a pull up or down on the counter-weight, or, to express the same. princi )le in diferent terms, by a pull in one or otlier direction on the counter-weight connection. This method of operation is the simplest of any, and is practicable whenever such a bridge is not required to approach a vertical position.,i When, however, such a bridge approaches the vertical position the effective lever arn of its center of gravity about its pivot becomes less and less, becoming zero when the center of gravity of the brid e is vertically over the pivot. And, simi'arly, the lever arm of the counter- Weight must also diminish as the bridge ap- Specication of Letters Patent.

drums, sovthat the need of costlyy 'Patented Aug. 31, 1915.

I Application tiled March 20, 1913. Serial No. 755,600.

proaches the vertical, in order to maintain the said balance; and when the center of igravity of the bridge is vertically over the ridge pivot the line of pull of the counter- Weight connection must also pass through the bridge pivotal, Consequently, in this position, neither the weight ofthe counterweight, nor any increased or diminished pull on theounterrweight connection, canhave anyetfect n tbbridge; andi'i'n'dei" 'such circumstances the .counter-weight connection could not be utilized to hold the bridge secnrely in that position against the pressure of the wind.

The bridge, when in a vertical or nearly vertical position, is subjected to the greatest wind pressure, and it is then that the greatest force is required to control it, and, asin this position a pull on the counter-weight or its connection is not effective, other means must be employed. Heretofore such means have been external to lthe counter-weight system,

and have consisted oi hydraulic rams, roekers, yconnecting rods, gearing and the like. But such means ai'e complicated and expensive, andare dii'liciilt to install w'ithout 'encroaching on the space required for roadways, sidewalks and necessary structural.Y

members; and it is the object of this invern,

tion to so arrange counter-weight eonnec. tions that all such complicated means may' be avoided and the bridge may be operated .iny all positions by simply pulling on a counter-weight connection or on a counter-Weight itself. I cfi'cct this result by using tiy or more counter-weight connections, one or more being attached to the bridge by rigging so that the tensions on all the counterifi-'eight connections together balance the 95 bridge in. all positions. able points oi' attachment to the bridge t'or the various counter-weight connections, then, when the linc'ol pull ot one counter-Weight connection passes through the bridge pivot, the line of pull of others may be'substantially distant from the pivot and these connections will be capable of controlling'the bridge. Usually but two counter-weight connections are needed for each side of -the bridge, and one of these-can be so attached to the bridge as to always have a substantial, leveragearound the pivot, and the line of piill'otl the other counter-weight connection only needfpass through the pivot during the M0 motion ot the bridge, and the bridge can be controlled completely by pulling on the first y choosing suitmentioned coiinter-weight connection or its countcnweight.

Various n'ieans to produce the pull on the connection. and `various ar rangements ot' counter-weight and connections may be used, and l. have shown in the accompafryingv drawings several oi the pre- Alerred arrangi'ements: but l'do not confine in vselt' to an)Y particular means orarinngg'e ment. l prefer to use geables for the counter-weight connections. and hereinafter use the word cable" when. referring to suc-h a connection, although the connections may be constructed ol: chains, link bars, and other suitable devices.

l-lleterringv to the said drawings which accompany the specification to aid the descrip-- tion, Figure l. is an elevation of a bascule bridgre equipped with my courriel-balancing device. in the a rrangement preferred for the case'wheu it is desired biplace the controlv ling machinery in atower and inmiediately over the roadway. Fig. il is an leleJation of the arrangement preferred when it is desired to place the winding machinery at the top of a tower. Fig. 3 is an explanatory7 diagram indicating Yarious positions of the bridgel shown in Fig. l.

lt will b understood that the igures show the counter-imiancing devices for only7 one side' ol: the bridge, but that generally in pracM ticethese devices will be-duplicated,there beingsr one set of such devices for each side ot' the bridge. '.lhcrefore in the description which follows reference made to diede` vices on the one side only, the corresnonding parts on the other side oic the bridge being similar to those described.

vReferring to Fig. ,L -B is a bascule bridge: A-A being` the piers, l the pivot about which the bridge turns, T the tower, the main counter-weight cable, and (l1 the secondary counter-weight cable. and 51 are ,guide sheaves respectively :t'or said cables (l and i" on the top ot' the tower; W and ld are the main and. secmidar)Y counter-weights, and l) is a winding drum for operatingthe .secoiular7 counterwcigiht cable (ll. 'lhe joint weightV of saidv counterareifihts 1W and ll 'is preferably just suflicicnt to balance said bridge B when the latter is in its lowest position. The .secondary counter weight cable (ll is attached to some suitable point o'l the bridge, as the elbow of tbewnpper chord 7*'. audithe said primary cable l passes" around 'a saddle l?. and .is t `,tened to said bridge at some point back 'olc said saddle F, and prcierabl)Y at the pivot l), said saddle forming a curved way or guidel on wliiclnthe cable is laid.' Said saddle l1" is secured, preferablyr to the upper side ol: the, bridge as shown. by any suitable framing; such as the, post and tie rods f--1. les the bridge rises to different positions .the ral'ilef C will 'olf course unwrap from the saddle, said cable forming the tangent to the curve. The curve of the face Oi' said saddle l." on which said cable (l laid,is formed so that the moment of the cables oi the main weights lli/v added to 'the moment of 'the cables of the y weights il will equal the n'ioment of tne bridge around. the piVotP-i/. e. 'the priniiaiw weights lV multiplied by the mrpendieular distances from the'pirot l.I to their cables C plas the secondari,T weights lln'iultiplied bv the pernendicular distances from the pivot l to their cables C1 must equal the weight of the bridge multiplied by the horizontal distance from the pivot P to the'vertical throng-h the center' of gravity of theV bridge; said perpendicular distances from the pivot l to the line of pull o16 the respective cables being their lever arms, or algeliraicallv eXvi in which vW and W represent the total weight of the respective we weights, and l represents the weight ot the bridge, 1 the radius from the pivot P to the center of gravity of the bridge, and OC the angle which said ra dias n'fikes with the horizontal. To effect the control of the bridge,

the point of attachment fof said secondary7 cable C is prelerabl7 so chosen that the lever arm il of said cable C is alwars of substantial length. and therefore the moment WIW will always be a substantial quantity. ',lhcrefore as the bridge risesandthe ingle oc increases audits cosine diminishes the right hand member ot' the equation becomes less and less until at some point between the horizontal and the vertical positions of the bridge, it equals' lVll and the. term WZ then becon'ics e'qnalvt-o zero,-f. c. Z must be equal to zero, and the. line of' the cable l then passes thi-nigh the pivot l? in this position oi the bridge. As the bridge continues .its upward motion the term Vfl becomes negar tire, and the pull ol: the cable (l becomes opposed in its etlcct on the bridge to the pull oi? thecable l", and thus an etlicient and siniple niians of oiieratinfi and controlling the :bridge is provided. Moreover, as 4the bridge continues its said upward motion` the cables being' connected to the bridge at Athe pivot l),- will-no longer remain in contact with the said .saddle l?, and a second reversed saddle l*v is preferably used to cli'ect the aforesaid opposition to the pull ot' the cable (l, and to complettuthebalance during the remaining upward movement of the bridge. il; the point oil attaclnncnt oi the said cables C to the bridge is placed high enough above the pivot l. a/singifle, curve l? can be used and the said reversed curveI li" ma;7 be dispensed with. but this usually necessitates the int-ro'- duction of otherwise superilucfus structural ghts, andi and 1 'the lever-arins of the respective counten" bridge descends.

curve F. The bridge being balanced in all positions byl the combined weights W and W', it is manifest that if we pull down on the weight W or pull on its cable C, the balance .will be destroyed and the bridge will rise, and conversely that if we pull up on the said weight W the bridge will de scend. l accomplish this pull by attaching the secondary cable C to a winding drum D,"preerably by Wrapping it'several times faroundvsaid drum and attaching it to said drum,'and ofcourse said cable C may be in two separate parts, one extending from the point 'of attachment f'to drum D, and the other from drum D tothe counter- Weight W. When said drum l), arranged as in Fig. l, is revolved in the direction of the hands of a clock the bridge rises, and when revolved in the reverse direction the Said drum D may be revolvcd by any suitable means, as by gear G and pinion y 0n shaft efsaid shaft c being revolved by any suitable motive means such as a steam or gas engine or electric motor. Suitable brakes should be provided for stopping the motion of the 'said drum 0bviously the power to lift the bridge is only limited by the power available to turnthe .drum D and the strength of the cable C. .But the maximum in' lowering the bridge is obtained when the'drum D lifts the entire A weight l/V; hence the Weight Vf must be so preferably to the top chord of the bri'dge.

heavy that its moment shall exceed the greatest moment that can be Vproduced by the greatest wind pressure against which it is intended that the bridge shall be operative. plicity have been hereinbefore described as single members, but they will generally consist of a multiplicitir of smaller ropes acting in unison.

Referring to Fig. 2, which shows the arrangement I prefer when the winding ma.4 chinery is to be placed at the top ot the tower, the secondary cable C is attached at a suitable point f beyond the saddle l?. and is carriedA over the guide sheave S and around the drum D and down to the counter-weight 'W'. In this case the travel ofthe cable C is much greater than when ar` ranged as in F ig. l, and therefore, to avoid greatly increasing the height of the tower T, l prefer, instead of attaching the secondary cableC directly to the weight W, to pass said secondary cable under a reduction sheave S2. attached to the weight W. and thgnce up to and attach it at some point as A y .k near the top of tower T, and thus reduce the\'tra\ fel of the said weight W to one-half of the travel of the saldsecondary cable C.

lf a greater-'reductionlisfreguired more re- The said cables C and C for siinducing sheaves .may be introduced. 0b-

viously, as the motion of the weight W is main weight lV, its cable C and the saddles F and l" are the same as described in connection with Fig. 1; andthe operation of thevbridge by means ot drum D is also the same, except that as shown in Fig. 2, the rotation of drum D for the up and down motion of the bridge is preferably the'reverse or" that indicated in Fig. 1; also we may drive the guide sheave S by the pinion g and a gear G, and then by'wrapping the cable C a suiicient number of times around drum D and sheave S we may obtain Sullicient adhesion between the cable C and the drum. D and sheave S', to operate the bridge without positively fastening the cable C to the drum l).

Fig. 3, isa diagram showing elements of Fig. l in v'ariouspositions, similar' letters f indicating similar parts and the numerals corresponding to the various positions. This diagrammatic ligure .shows clearly the action of the saddles F and F in varying lever arm Z ofthe cable C in conformity with the aforesaid equation. l

To check the bridge on its upward motion, lprefer to provide a buffer X in all modifications of the invention, so located on the bridge l that when said bridge is approach# ing its vertical position said buffer will con- `tact with said cable C, and should any cause, such as a still wind, terid to move said bridge back beyond its proper position, said buii'er X will press on said cable C and" cause said counter-weight W to resist any'further backward movement of said bridge. The bearing surface of said buiier X is curved on a radius sutiiciently easy to 'allow said cable C to bend without injury.

Now having described. my improvements l claim as my inventionl. The combination. with a bascule bridge of a plurality of counter-weights, `one of which counter-weights is operatively connected with said bridge at a point substantially dista-nt from the pivot from said bridge, means to raise and lower Said couni ter-weight, and operative connection from another of said counterweight to, said los bridge, and curved members in contact with said last named connection and adapted .to

' vary the leverage of said connection such that said plurality of said counter-weights in the aggregate balance said bridge in all its positions.

2. A. combination with a bascule bridge motion of the hririgfny and :t reverse, Saddle to Yury thv heu-r :irm of sont connor-tum ihiring theI rmnninilvr of thv inotion of tho hrids'r so thnt thi' two (connrtions togcthor hnhlzno thv hridgu in :xii its positions.

I3. Thi- (conihinntion with n imncnio bridge, oi two rmintor\\' \i;ht animations operatively connwtmi with tin bridge, :i ooi-wei sanhiio :nlnptwi to Yury thvy ion-r nrxn ot' ono oi smid roniwrtiomI (hiring n portion ol tho Inotion ot ihr hrnigr, :ind n rovers@ #anhih to vnr): the` ,hrvii :irin of forni ronnortion. (inw ingY tin rif-inniznlvr of thel motion o'l thu hridrg'o so that thi tiro ronnwtions togvthrr hnhnno thil in'iilgfn in :iii its positions, und means to Yury tinl trnsion on ono ofszlid connoctnms.

4. TheI coinhinntion with :l hnsrixio bridge o'lf (counter-right connections opcrntiwiy connected with tho bridge, curved sznhihzs adapted. to Yury tho hvor arm ol suicl con` nefztions hiring :1 portion of tho motion of tho bridge und rowrso sndiilos to Yury tho ioi'or :irm of smid ronnvctions during tht)l remainder oi thu motion o'l' thv bridge.

5. The combination in n hnsonio initig'r of ronntir-woigfhts. so that snici two sots of ronntvrwvigrhts togothor hninnco tiho bridge in nl! itsvllositions.

Sigurd :it Non' York rity in thi.l ronnty of Non York :uni Stato of New York'this ehevcnth tiny oi' March, A. D. 1912i.

THOMAS 1C, BROW'N.

Images