US1140316A - Vertical-lift bridge. - Google Patents

Description

T. RALL.

VERTICAL LIFT BRIDGE.

APPLICATION FILED MAY 19. 1913.

' 1 14%,3 1 $0 Patenteoi May 18, 1915.

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VERTICAL LIFT BR|DGE. APPLICATION FILED MAY 19. 1913.

LMQEI 6o Patented May 18, 1915.

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WETIGAL-LIFT Specification of Letters fieatent.

Patented May id, 3915..

Application filed Hay 19, 1918. Serial EQ 0. 768,551.

ToaZZ whom it may concern Be it known that T, Tnnonon BALL, a citizen of the UnitedStates, residing at Chicage, in the county of Cook and State of Illinois, have invented certain new and useful Tmprovements in Vertical-Lift Bridges, of which the following is a specification.

My invention relates in general to movable bridges, and more particularly to vertically lifting bridge spans.

The primary object of my invention is to provide a -vertically movable bridge span with simple, eiiicient means for counterbalancing the weight of the span and compensating for the expansion and contraction of the span, due to changes in temperature.

A further object of my invention is to provide a vertical lift bridge which will be simple in construction, efhcient in operation, and convenient in use. My invention will be more fully disclosed hereinafter with reference to the; accompanying drawings, in which the same is illustrated as embodied in several convenient practical forms, and in which- Figure l is a side elevational view; Fig. 2 a plan view of the embodiment of the invention shown in Fig. 1; Fig. 3 a view similar to Fig. 1, showing a modified form of my invention; and Fig. 4 a view similar to Fig. 1 showing still tion.

Similar reference characters are used to designate similar parts in the several figures of the drawings.

Reference letters A and B designate stationary approach spans, between which is located a vertically movable span E. The approach and movable spans may be of any suitable construction, such, for instance, as trussed bridge spans.

C, D designate piers upon which the ends of the stationary spans A and B, respectively, are permanently supported, and upon which the ends of the movable span Fl normally rest.

G and H designate levers in the form of trussed girders, which are pivotally fulcrumed at g and h, respectively, upon tower posts N and U mounted directly-upon the piers C and D and secured to the adjacent stationary spans A. and B. Each of the lovers G and ll is provided with a weight to counterbalance the weight of the vertically movable span. The end of each of these levers, opposite to the end on which another form'of my haven-- the counterbalance K is mounted, is provided with a roller L, which engages beneath a track M fixed to the upper chord F of the vertically movable span.

it will be understood by reference to Fig. 2 that the lifting levers G and i land the parts coiiperating with themyare arranged in pairs, one pair being located at each end of the movable bridge span.

Any suitable mechanism may be provided for raising and lowering the span E, such mechanism being shown as comprisin a longitudinal shaft P journaled upon the lift ing-span E and provided with pinions ffixed to its opposite ends, which mesh with racks 71. secured to the vertical posts N and 0. Any suitable arrangement of shafts and gears may be provided for rotating the shaft P, such, for instance, as a vertical shaft Q mounted upon the movable span E and operatively connected at one end by meshed bevel gears q with the shaft P, and its other end by meshed bevel gears r with a power shaft R, which may be rotated by any suitable motive power, I such, for instance, as electricity or steam, or by hand.

The operation of my improved lifting bridge, as illustrated in Figs. 1 and 2, is as follows: When it is desired to lift the span' E, theshaft P is rotated, which causes the pinions p, through engagement with the fixed racks n, to travel upwardly thereby raising the span E between the posts N and (l. The weights K on the outer ends of the lifting levers G and H counterbalance the weight of the span Fl during its vertical movement. During the upward movement of the span the supporting rollers ill have paths of movement in the arcs indicated in dotted lines in Fig. 1. owing to the lifting levers being pivoted at g and h, respectively, upon the tower posts. During the lifting of the movable span the rollers L on the inner ends of the levers roll inwardly along the tracks M until the rollers lie in the horizontal plane of the fulcrums g and h of the lifting levers, and during the remaining lifting of the span the rollers move outwardly relatively to the tracks M, which they engage, and through which they transmit the lifting power oi the levers. In order to lower the span it is merely necessary to reverse the direction of rotation of the shaft P.

Tn the form of my invention illustrated in Figs. 1 and 2, the horizontal distance between the fulcrum of each lifting lever and by providing the levers with rolhng fu'l- I terbalancing wei ht while its inner en is ivotallv connected at crums. acters A and B esignate stationary tower posts at the op osite ends of the vertically movable sp'an' such tower posts being mounted upon the piers C and D, respectively. G and H designate thelifting le vers, each of which is rovided witha counat ,its outer end,

L to the upper chor F of the an E. The fulcruins of the levers G and consist of rollers g and h, respectively, which rest upon tracks a and b on the tops of the tower posts A and B. raising and lowering the span in the form ofmy inventionshown in Fig. 3 may be the same as above described in connection with Figs. 1 and 2, or any other suitable lifting mechanismmay be provided.

In the operation of the embodiment of my invention shown in Fig. 3 the fulcrums g and h of the lifting levers G and Hi roll outwardly until the pivotal connections L of the liftin levers with the top chord of the span reac the horizontal plane of the fulcrums, after which the fulcrums roll inwardly, or toward each other, during the remaining lifting movement of the span.

In Fig. 4 I have illustrated still another embodiment of my invention, in which the pivotal movement of the lifting levers during the vertical movement of the span is compensated by providing merely one of the levers with a rolling fulcrum. In this figure reference characters A and B designate the tower posts mounted upon piers C and D, respectively. IE designates the lifting span, which normally rests at its ends upon the adjacent piers. G and H designate the lifting levers, each of which is provided at its end with a weight K for counterbalancing the span. The inner end of each of the lifting levers is pivotally connected at L to the upper chord F of the span E The lever G is pivotally fulcrumed at 9 upon the top of the tower A, while the lever H is provided with a rolling fulcrum k which rests upon the track b at the top of the tower B.

In the operation of the embodiment of m invention shown in Fig. 4, durin the-lifting of the span the fulcrum h o the lever Referrin to Fig. 3, reference char- The means for H shifts outwardly along the track 6 until the pivotal connections L of the lifting levers with the up er chord of the span reach tlnrhorizontal p ane of the fulcrum. of the levers after which'the fulcrum k of the lever I-I rolls inwardly durin the remaining lifting of the span. It wi be observed, by reference to Fig. 4, that in the form of my invention shown therein, the ends of the bridge are moved in arcs indicated in dotted lines, when the bridge israised or lowered.

In the several forms of my invention herein illustrated and described, not only is the pivotal movement of the lifting levers during the raisin .and lowering of the span compensated for, ut the expansion and contraction of the span is also compensated for through the shifting either between the vers and the span or between the levers and the tower posts upon which they are fulcrumed.

From the foregoing description it will be observed that I have invented an improved lifting bridge which may be vertically raised or lowered by means of piv otal levers, the pivotal movement of the levers during the vertical movement of the bridge span being compensated by means for varylng the horizontal distance between the fulcrum points of the levers and the pivconnections provided otal connections of the levers with the span. It will also be observed that in my improved mechanism for lifting brid spans the expansion and contraction o the span is so compensated as to in no wise ail'ectnthe efficient operation thereof.

1. In a bridge of the classdescribed, the combination with a'vertically movable span, of stationary supports at each end of said span, and counterbalance levers pivotally mounted upon said supports and pivotally connected directly with the opposite ends of said span, the pivotal connectipns of one of said levers comprising one fixed'pivot and one pivot in freely movable engagement with a substantially horizontal track for automatically varying the horizontal distance between the fulcrum point of said lever and its point of pivotal connection with the adjacent end of the span to compensate for the pivotal movementofsaid lever during the vertical movement of said span.

2. In a bridge of the class desc -'ibe(l, the

combination with avertically movable span,

of stationary supports at each end of said span, and counterbalance levers pivotally mounted upon said supports and pivotally connected directly with the opposite ends of said span, and the, pivotal connections of each of said levers comprising one fixed pivot and i one pivot in freely movable engagement with a substantially horizontal track for automatically varying the horizontal disincome tance between the fulcrum oint of eachlever and its pivotal connectlon with the adjacent end of the span to compensate for the pivotal movement of the levers during the vertical movement of the span.

3. ln abridge of the class described, the combination with a vertically movable span, oi stationary supports at each'end of said span, counterbalance levers pivotally mount-- ed upon said supports, and means for pivotally connecting said levers directly with the opposite-ends of said span, the means for pivotally connectin one of said levers with the adjacent end 0% the span consisting of a pivot in freely movable engagement with a, substantially horizontal track to compensate for the pivotal movement 013 said lever during the vertical movement of the spam 4C. lln a bridge of the class described, the combination with a vertically movable span, of stationary supports at each end of said span, counterbalance levers pivotally mounted upon said supports, substantially horizontal tracks upon the opposite ends of said span, and pivots on the ends oil said levers in freely movable en agement with said substantially horizonta tracks, the point of pivotal connection between each of said levers and the adjacent end ol the movable span to compensate for the pivotal movement of said levers during the vertical movement of the span.

5. in a bridge of the class described, the combination with a vertically movable span, of stationary supports at each end of said span, counterbalance levers pivotally mounted upon said supports and pivotally connected with the opposite ends of said span, the pivotal connection between the end of one of said levers and the adjacent end of said span comprising a rolling bearing and a member engaged thereby whereby the horizontal distance between the fulcrum point of said lever and its connection with the span will automatically vary during the vertical movement or the span to compensate for the pivotal movement of said lever.

8. ln abridge of the class described, the combination with a vertically movable span, of stationary supports at each end of said span, counterbalance levers pivotally mounted upon said supports and pivotally connected with the o posite ends or? said s an,

the pivotal connection between the en of each of said levers and the adjacent end of said span comprising a rolling bearing and a member engaged thereby, whereby the horizontal distance between the in c was pointspl the levers and their connection with the span will automatically vary during the vertical movement of the span to compensate for the pivotal movement of said levers.

7. In a bridge of the class described, the combination with a vertically movable span, of stationary supports at each end of said span, counterbalance levers pivotally mountvertical movement at the span to compensate "for the ivotal movement ofsaid lever.

8. In a bridge or? theclass described, the combination with: a vertically movable span, of stationary supports at each end of said span, counterbalance leverspivotally mount- 1 ed upon said supports an pivotally connected with the opposite ends of said span the pivotal connection between theen oil each of said levers and the adjacent end of the span comprising a track fixed to the span and-a roller on the end of the lever engaging the track, whereby the horizontal distance between the fulcr points of said levers and their connections with the span will autotically vary during the vertical movement of the span to compensate for the pivotal movement of said levers.

9. lln a bridge of the class described, the combination with a vertically movable span, of stationary supports at each end of said span, counterbalance levers ivotally moun ed upon said supports an pivotally connected with the opposite ends of said span, the pivotal connections of one of said levers comprising one fixed pivot and one pivot in freely movable engagement with. a substantially horizontal traclr for compensating for the expansion and contraction of said span.

lln testimony whereof, ll have-subscribed my name.

THEUDUR -RALL.

Witnesses @139. lb. Wmnrnson, lrllnnnv n. Penn's.

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