US974538A - Bridge. - Google Patents

Description

J. B. STRAUSS.

BRIDGE.

APPLICATION FILED [18.9.1808.

Paiaented Nov. 1,1910.

UNITED STATES PATENT OFFICE.

JOSEPH B. STRAUSS, OF CHICAGO, ILLINOIS.

' To all whom it may concern:

Be it knownthat I, Josnrn B. STRAUSS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Bridges, of which the following is a specification.

This invention relates to bascule bridges and has for its object to provide a new and improved bridge of this description.

Figure 1 illustrates one form'of bridge embodying the invention; Fig. 2 is a plan view of the counterweight.

In this construction a moving leaf 1 is pivoted at its heel or extreme end so that it may be opened and closed. As herein shown the moving leaf is pivoted at 2 upon the fixed support 3 by means of horizontal trun- I nions or pivots, said trunnions or pivots being below the roa way. The center of gravity of the moving leaf is diagrammatically illustrated at 4. The lever arm of the moving leaf is the distance of its pivotal point to the center of gravity 4. A counterweight 5 is pivotally mounted by horizontal pivots or trunnions at 6 upon the support =7,

the pivots of the counterwe1ght being out of yalinement'with the pivots or trunnions of the moving leaf As herein shown the counterweight 5 is not directly pivoted to the support 7 but is attached to a counterweight frame 8, the frame being pivotally connected to the support. The support for the counbetwe'enthe ivotal forward en terweight" may be formed in any desired manner, and it may be mounted upon a secondary span, the direct carrying part for the counterweight being preferably a bell crank as shown in Fig. 1. A counterweight link-9 is pivotally connected with the counterweight and'with the moving leaf. The connection with the moving leaf is shown ahead of the trunnions of said leaf, that is, oint of the leaf and its and ack of the center of gravity of the moving leaf, this pivotal connection being shown at 10. A fixed approach across thespace above the roadway. It will be noted that the counterweight frame has two arms one on each side of its pivotal connection with the support, the counterweight being attached -to one armand the counterweight link or connection being attached to the other arm. The counterweight may be of any suitable material, but it is Specification of Letters Patent.

Application filed March 9, 1908. Serial No. 419,982.

BRIDGE.

Patented Nov. 1,1910.

preferably constructed of concrete or'concrete stee The radial distance between the pivotal point 6 of the counterweight and the piv-' otal point 12 of the link 9 is the same as the radial distancebetween the pivotal point 2 of the moving leaf and the pivotal point 10 where the link 9 is connected thereto. The

line joining the pivotalpoints of the counterweight and the moving leaf is equal and parallel to the line joining the pivotal points 10 and 12 of the link 9.

The .moving leaf is operated in any de sired manner, as, for example, by the oper ating strut 13 having the rack 14- which engages the gear 15 driven from any suitable motor. When it is desired to open the bf ldge the motor is operated, and the moving leaf counterweight is connected to the moving leaf at the top line thereof. 4

The line joining the center of gravity 4 of the leaf and the pivots thereof is parallel to a line joining the center of gravity 14. of the counterweight and the pivot 6 upon which it is supported.

In the usual form of bascule bridge where the trunnions are located near one end instead of at the end, asin the present (ase, the more expensive counterbalance members are decreased by the use of a larger amount of the comparatively inexpensive counterweight. By means of the present construction this principle is applied to a bascule bridge pivoted at its heel or end, thu's securingthe same economy of construction.

'ent case is detached from the moving leaf and has a comparatively short lever arm and a one-piece link connection to the movwhen in all of its other positions. The point of attachment of the l1nk is in a different horizontal plane from the trunnions and the attachments of the link to the leaf and the The counterweight in the preswhen' the moving leaf is closed, and also counterweight frame are both back of the trunnions when the leaf is open. The angular motion of the center of gravity of the leaf and the center of gravity of the counterveight is the same.

It will be seen that in this construction it may be said that the tail end or part of the moving leaf. is separated therefrom and upon which the counterweight and the girder towhich it is attached are carried has the two sets of trunnions at the two acute angles thereof, and the relation of the parts is such that vertical reactions only are provided on the two supports, as the other reactions counteract each other. I The constructlon shown herein is partlcularly adapted to secure the maximum 0 en span. It will be noted that when the bri ge is open the counterweight passes between the supports upon which'it is mounted, and that the center of gravity of the moving span moves back of its pivots. The link 9 acts as a tension member during a part of the movement, and then as a compression member, and hence this constructiolrpermits the complete opening of the span. If the span had to be stopped before the center of gravity passed the pivots, would be only partially open. I

' This construction particularly. adapted for large and massive structures, and the' parts are arranged so that the reactions upon the foundations are kept constant and vertical, that upon the pier supporting the moving leaf being equal to the weight of the counterweight and sup ort. The reactions are such that all other orces, other than the vertical forces, counteract each other, and hence have no effect on the foundations. It will be noted that the vertical line drawn through the center of gravity of the counterweight, and the line passing through the axis of the link 9 intersect above the trunnions on which the counterweight is sup: ported, and thatthe line joining this point of intersection and the trunnions of the counterweight passes between the supports or piers upon which the counterweight and moving leaf are supported. It will be noted that the lever .arm of the counterweight and link 9 are both shorter than the lever arm of the moving leaf.

The counterweight link, it will be noted,

is connected not at the center of gravity of the leaf but back of said center of gravity, and this brings in certain non-vertical forces which tend to overthrow or injure the foundations when the moving leaf and counterweight are pulled toward each other'during the openin of the bridge. This construc tion provides means for annulling these non-vertical forces.

l claim:

1. A bascule bridge comprising a'moving leaf'mounted upon horizontal pivots at its heel and terminating at said pivots, a counterweight carrying part mounted on fixed horizontal pivcts behind the leaf pivots, the two sets of pivots separatelysupported, a rigid link connecting the in ring leaf and counterweight, the vertical. line through the center of gravity of the counterweight and the line passing through the axis of the link intersecting above the trunnions on which the counterweight is supported.

2. A bascule bridge comprising a movin leaf mounted on horizontal pivots at its hee a counterweight carrying part mounted on fixed horizontal pivotsbehind the leaf pivots, two separate supports, one for the leaf and the other for the counterweight suport, a rigid link connecting the moving leaf with the counterweight, the verticalline 'through the center of gravity of the counterweight and the line passingthrough the axis of the link intersecting above the trunnions on which the counterweight is supported when the bridge is closed, the

line joining said point of intersection and the trunnions of the counterweight passing between said supports.

3. A basculebridge comprising'a moving leaf pivotallyconnected to a support, a separate counterweight carrying part pivotally mounted behind said leaf, a counterweight carried thereby, a rigid link connecting the leaf with the counterweight carrying art, the lever arm of the counterweight and the lever arm of the link. being both shorter than the lever arm of the moving leaf, the lever arm of the'link greater than the lever arm of the counterweight and less than the lever arm of the leaf.

4. A bascule bridge comprising a moving leaf mounted on horizontal pivots at its heel and terminating at said pivotsfa counterweight carrying part mounted onfixed hori-' zontal pivotsbehind the leaf pivots, the two sets of pivots separately supported on fixed terweight being in front of the counterweight carrying part wh n the bridge is in its open position. a e I 5.. A bascule brrdgecomprising a moving rying part.

' the center 0 leaf, a separated counterweight, a-rigid link connecting the counterwei ht to the leaf, pivots at both ends of said link separate supports for the leaf and counterweight, and

a mounting frame in combination therewith adapted to produce only vertical reactions on the two supports, the reaction on the front support being substantially equal in all positions of the leaf between its open and closed positions to the weight of the leaf, and the reaction on the rear support bein substantially equal in all positions of the leaf between its open and closed positions to the weight of thecounterweight and its support. r, I

6.A bascule bridge comprisin a moving leaf mounted upon. trunnions an terminating at said trunnions, a counterweight car-' rying part mounted on fixed trunnions behind the leaf pivots, the two sets of trunnions separately sup orted, a rigid link connecting the moving eaf and counterweight,

parallel'to the line connecting the counterweight trunnions and the polnt where the link is connected to the counterweight car- 7. A bascule bridgecomprising a leaf, two frames each provided with members which converge to apoint, one frame fixed and the other movable, 'the two frames movably connected together -at their converging said link connected with said counterwei an operating device connected with the points, a counterweight attached to the movable frame, and a rigid link transmitting the counterweight stress to the leaf.

8. A bascule bridge comprising a moving leaf mounted upon pivots, a counterweight carrying part mounted on pivots behind the leaf pivots, the two sets of pivots separately supported, a counterweight carried by the counterweight carrying part, a rigid link connected with the leaf at a point intermediateits pivots and its center of graviply,

ahead of its pivots and with the support for n the counterweight pivots, above said leaf pivots, and means for eliminating the horizontal forces produced in the supports.

9. A bascule bridge comprising a moving leaf mounted upon pivots at Its heel, a

counterweight carrying part mounted on pivots behind the lea having an inclined member which connects the two sets of pivots, a rigid link connect-' ing the counterwei ht carrying part and the leaf and connecte with said leaf ahead of g leaf pivots, a separate support for the counterweight carrying part the leaf pivots, said link parallel to said inclined member.

v 10. A bascule bridge comprising a'fbrid truss and a counterweight truss, separate y supported, one member of the bridge truss parallel to a member of the counterweight truss, and connectin members'between the ends of said paralle membersone of said members connected with said leaf ahead. of

the leaf pivots.

' JOSEPH B. STRAUSS.

Witnesses: WALTER Ernns, EDNA K. Remotes.

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