US1146283A - Pivotal suspension-bridge. - Google Patents

Description

A. C. RUSH.

PIVOTA'L SUSPENSION BRIDGE.

APPLICATION FILED AUG. 15, 1912.

1,146,288. Patented July 13, 1915.

3 SHEETSSHEET I.

Inventor 4 Dan C? Ewh/ COLUMBIA FLANOGRAPH CID-.WASHINGTDN. D. c.

A. C. RUSH.

PIVOTAL SUSPENSION BRIDGE:

APPLICATION FILED AUG.I5, 1912.

Patented July 13, 1915.

3 SHEETS SHEET 2.

ZAQ 5,

COLUMBIA ELANOORAPH 120.. WASHINGTON. D. .4

UNITED STATES PATENT OFFICE- ALLAN C. RUSH, 0]? LOS ANGELES, CALIFORNIA.

PIVOTAL SUSPENSION -BRIDGE.

Application filed August 15, 1912.

To all who-m it may concern:

Be it known that I, ALLAN C. RUSH, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Pivotal Suspension-Bridge, of which the following is a specification.

An object of thisinvention is to provide a structure capable of use for bridging over a wide space such as exists between San Francisco and Oakland in which the spans may be as great as from 2200 to 3000 feet between the piers, such lengths of spans being deemed desirable owing to the great depth of the channel between San Francisco and Goat Island, in which channel it is contemplated to construct piers to as great a depth as one hundred and fifty feet, more or less. I

Objects of this invention are to overcome the objections and disadvantages to which suspension bridges have heretofore been subjected, among which may be mentioned as most prominent, in urious oscillations in the roadway due to the cables altering their curvature under the varying distribution of a moving load; lateral and vertical oscillations due to wind pressure; the disruptive effect due to severe seismic disturbances; and the stresses due to expansion and contraction which in San Francisco amount to about 9/l6ths of an inch'to every one hundred feet.

To minimize the wave-like undulation caused in the ordinary suspension bridge by a fast-moving load, such as a railroad train, I provide a series of sections jointed together, each section being fifty feet, more or less, in length and comprising longitudinally stiffening deck-supporting frames, columns connecting the frames to the supporting cables, transverse deck-beams supported by the frames, and Suspender-beams transversely connecting the Suspender-columns.

To minimize the lateral and vertical oscillations caused by wind pressure and yet provide sufficient flexibility of the structure to meet the distorting effect of. great physical disturbances, such as earthquakes, the deck-supporting frames and Suspender-columns are jointed, the deck-beams are pivoted to the deck-supporting frames, the sus pender-beams are pivoted to the columns,

and the deck-rails exert pressure on the sus- Specification of Letters Patent.

Patented July 13, 1915. Serial No. 715,285.

pender-beams; and the pivots of the deckbeams are eccentric to the pivots of the suspender-beams so that the pressure of the deck-rails on the Suspender-beams will produce friction when the deck-rails and suspender-beams are relatively moved by swinging of the columns caused by wind pressure or the like.

The deck-supporting. frames and suspender-columns form in effect a pendulum of which the oscillating axis is the pivot of the Suspender-beams and the vibrating end of the pendulum is the pivot of the deckbeams so that a horizontal plane cutting through said vibrating end will approach a horizontal plane cutting through the oscillating axis when the pivots are shifted out of plumb, and it is clear that any member mounted to move with the plane of the oscillating. axis will be shifted horizontally along and raised relative to said plane when the pendulum is swung out of the vertical, thus in the case of the bridge elements, reducing the friction between the deck-rails and the Suspender-beams from a maximum when the columns are vertical to a minimum when the columns are aslant in order that, if the swaying becomes excessive under high wind pressure or violent seismic disturbances, the sections will be perfectly free to lift and swing at the pivots and avoid disruptive strains on the cables.

To minimize swaying of the cables caused either indirectly by the effect of wind pressure on the suspended structure or directly by shifting of the piers caused by an earthquake or the like, the cables are arranged in vertically-arranged sets forming superposed longer are than the upper cables, the weight of the structure-will tend to keep the cables in vertical alinement against the swaying action tending to throw them out of such alinementu y To allow for the free expansion and contraction of the bridge structure and make a the amount of such expansion and contraction negligible I distribute. thev expansion joints at frequent intervals along thestructure and form such joints at the suspenderbeam pivots between each declcsupporting frame and its adjacent column and the amount of movement at the joints will be very slight for if the amount of contraction and expansion is nine-sixteenths of an inch to every one hundred feet and there are two sections with four expansion joints every hundred feet, then the movement at any given joint to compensate for such contraction and expansion will be less than five sixty-fourths of an inch and at any given column about nine sixty-fourths of an inch.

An object of the invention is to provide a structure of this class in which all expansion and contraction is taken care of in such manner as to avoid any injury to the structure; to allow the structure to sway in the wind without strain or injury; and to so construct the bridge that the weight of the parts of the bridge will act in opposition to the swaying movement to minimize such movement.

The invention embodies a structure comprising a series of cables suitably connected to piers and connected together intermediate their ends; and longitudinally rigid and laterally flexible sections forming a framework suspended from the cables and adapted to carry the tracks and roadways.

The invention comprises the structure as a whole, and various combinations and parts hereinafter set forth and may be applied in various ways.

The accompanying drawings illustrate the invention.

Figure 1 is a fragmental side elevation on a small scale of a bridge constructed in accordance with this invention, one entire sec tion and parts of two adjacent sections be ing shown. Fig. 2 is an end elevation of one of the bridge sections in Fig. 1. Dotted lines indicate to an exaggerated degree a shifted position of the bottom deck due to wind pressure or other causes. Fig. 3 is a cross section on line indicated by 02 Figs. 1 and 2, portions of the pavement and suspender-beam being broken away to show the parts beneath. Fig. 4: is a fragmental sectional elevation along the bridge on line indicated by w, Figs. 2 and 5. Fig. 5 is a fragmental end elevation partly in section on line indicated by 90 Fig. 1 of one of the bridge sections. Dotted lines indicate to an exaggerated degree a shifted position of all the decks. Figs. 6 and 6* are diagrammatic transverse views illustrative of the lever principles embodied in the preceding views. Fig. 7 is a fragmentary detail partly in vertical mid-section of the suspender device in Figs. 1, 2, a and 5. Fig. 8 is a view of the unassembled parts which make up the suspender-cable connection. Fig. 9 is a view of the suspender sleeve and fragment of the suspender cable as the same may appear during'the process of assembling. Fig. 10

is a side elevation of one of the jointed decksupporting frames. Fig. 11 is a longitudinal sectional detail in elevation on line indicated by 00 Figs. 5 and 13. Fig. 12 is a longitudinal sectional detail in elevation on line indicated by 05 Figs. 5 and 1a. Fig. 13 is a plan view of the joint in Fig. 11. Fig. 14 is a plan section on line indicated by at, Fig. 12. Figs. 1, 2 and 3 are on the same scale, Figs. 4 and 5 on a larger scale, Figs. 7, 11, 12 and 13 on a still larger scale, Figs. 8, 9 and 1 k on a yet larger scale and Fig. 10 on a scale between that of Figs. 1

and 4t.

Portions of the structure, as the columns 4: and deck-supporting frames 5, are shown without respect to details of their structural makeup in order to avoid confusion; it being understood that they may be built in any approved manner by those skilled 1n the art. The substructure including the suspension cable anchors and supports are omitted to economize space in the drawings.

The bridge may be constructed of any requisite number of duplicate jointed sections 1 fifty feet, more or less in length, and provided with the desired number of decks which in the instance shown are two in number, a lower deck 2 and an upper deck 3, there being provision made to accommodate a higher third deck, not shown, which may be added to increase the capacity of the bridge.

The sections 1 are provided with normally vertical suspender-columns t and longitudinally from column to column with longitudinally rigid deck-supporting frames 5 jointed in common by pivot-pins 6 which in conjunction with other pivot pins 7 and bolts 8 join the sections together, the pivot pins 6, 7 and bolts 8 all being sufficiently long to form expansion oints and permit of maximum contraction of the frames and columns and all being provided with means as the nuts 9 to limit the amount of movement to a predetermined maximum in order to prevent the frames and columns from becoming disconnected. It is clear that this construction of expansion joints between the several sections allows one section to swing laterally at an angle to another section so that there will be practically no strains created in the various sections when said sections are swung out of longitudinal alinement with one another by any force tending to thus swing them. The nuts 9 may be locked by suitable means as at set screws 10.

The columns 4 are slotted to accommodate transverse suspender-beams 11 which are supported by the pivot pins 6 or 7, as the case may be, the pivot pins preferably passmg through the suspender-beams above the center of gravity thereof, so that when the columns are deflected from the vertical, the amount of vertical lift on the suspender 7 tion.

beams will, be minimized and the predominating mass below the center of gravity will resist any force tendingto swing the columns.

The deck-supporting frames 5 may be of any approved construction to obtain strength vided longitudinally thereof with deck fulcrum-beams 12 notched and perforated to form pivots or journals 13 which, at each deck, are eccentric of and lower than the Suspender-beam pivots 6 or 7, as the case may be, and are accommodated in notches 14 in the bottom edges of transverse deckbeams 15, thereby pivotally mounting the deck-beams relative to the deck-supporting frames 5 and columns 4 and parallel with the Suspender-beams 11. The notches l4: prevent slipping of the'deck-beams which may be further secured by journal-straps 14C. The upper faces of the suspenderbeams 11 and deck-beams 15 are substantially in the same horizontal plane when the columns 4 are in their normal vertical posi- By this construction it is seen that the pivot pins 6, 7 form the axis about which the journals 13 turn whenever the columns 4 and frames 5 may be swung pendulum-like from their normally vertical position by wind pressure or other power; such rotation occurring at all decks if the columns swing from end to end as shown in dotted lines in Fig. 5 and occurring only at the lower deck if the columns swing from their joints down as in dotted lines in Fig. 2, thus Causing the deck-beams 15 to rise faster than the gsuspender-beams 11; the actionvbeing diagrammatically shown at one deck. to an exaggerated extent in Fig. 6 Where if the journal 13 swings through a number of degrees m the Suspender-beam 11 and deckbeam 15 will remain in horizontal planes and their pivots will be relatively shifted in a horizontal directionby the'distance y and will relatively approach one another by the distance .2.

By providing the columns with" joints it is clear that when wind pressure produces lateral movement of that portion of the structure below the pivots 6 any tendency of the cables to lateral movement Will be minimized and furthermore will be counteracted to a great extent by free swinging of the structure below the level. of the joints as in Fig. 2, the structure above the level of said joints being free from lateral movement under ordinary conditions and being subject to such lateral movement only under extraordinary disturbances of the air, such as hurricanes, or by earth movements, such as seismic disturbances.

Each section 1 is provided with longitudinal upper deck-rails 16, 17"and,lower deck rails 18, all of which are riveted or otherwise secured to the deck-beams 15, the upper deck-rails 16 forming supports for, pavements 19 which may constitute roadways;

and for pavements19thatmay be used for foot and bicycle paths, and the upper deckrails 17 forming tracksfor rolling stock, not shown. a ,J a

The upper deck-rails 16,17 extend to about the middle of the Suspender-beams 11, where they form dovetail expansion joints 20 between adjacent sections, the deckrails 17. being provided with fish-plates 17 having slots 17 andv bolted to the rails 17; and the lower deck-rails 18 extend to within a slight distance of the suspender-beams 11 and are supported at theirends by frictionblocks. 21 which are bolted or otherwise fastened by bolts 21 to the suspenderbeams 11. It is noted from the foregoing that the deck is provided with expansion joints at frequent intervals therealong from end to end thereof, so that the total amount of movement due to changes of temperature will be. negligible and will not cause objectionableinternal stresses and strainstending to weaken the structure. The end. portions of the deck- rails 16, 17 and 18 normally exert pressure on the suspenderbeams 11 and friction-blocks 21 respectively,

such pressure being caused by the weight of the end portions of the rails and any load that may be on such end portions. 1

Bythis construction it isclear that-when the columns swing and cause relative transverse movement between the .ends of the upper deck-rails ;16, 17 and suspenderbeams 11, and betweenthe ends of the lower deck-rails 18 and friction-blocks 21, friction will occur during vslight oscillations of-the columns sufficient to check and suppress such oscillations, and the amount of such check will be reduced and the friction will be minimized and will be practically nil if the columns swingcomparatively far from the vertical as shown to an exaggerated-extent'in dotted lines in Fig, 6 where the column &- swings through the degrees as and the suspender-beam 11 and deck-beam 15 have relatively shifted horizontally by the distance and vertically by the distance 2, thus permitting the columns to swing freely when moved in an arcof unusuallength by agreat impelling force such as severe wind pressure-and earthquakes, and at the same time the rails will be relieved from forces tending to bend them.

The deck-rails 16, 17 are supported between adjacent deck-beams 15 and the deckbeams themselves are braced longitudinally of the bridge by tie-beams 22 which ,lie parallel with and between the lower deckrails 18- and upperdeck-rails 16 or 17, as the casemay be, and are fastened to the deck-beams.

Each section 1 is provided with upper and lower tie- rods 23, 24, the upper tie-rods 23 connecting the top and two intermediate frame chords 25, 26, 27 to the upper and intermediate deck fulcrum-beams 12, and the lower tie-rods 24 connecting the intermediate and bottom frame chords 28, 29 to the lower deck fulcrum-beams 12 so as to form deck-suspending means intermediate of the sides of the frame 5.

The columns 4 are provided at their lower ends with lugs 30 which project from the edges of the columns and beneath the sides of the frames 5 to support the frames in case of need. The columns 4 are provided at their upper ends with suitable means to fasten them to the supporting cables which may be constructed of several strands of wire, of chain, or of eye-bars connected together, and which are anchored in the usual or any preferred manner, not illustrated, to the substructure, not shown, and are preferably arranged vertically in pairs having upper cables 31 and lower cables 32; there being a pair of the cables for each longitudinal series of columns, of which series in the instance shown there are five.

The cables 31, 32 may be weather-proofed in any suitable manner by sheathing, not shown, and may be provided at intervals with bonding rings 33, and I have shown flexible connections between the cables and the columns 4 and pivotally mounted on the cables, the flexible construction allowing free pendulum-like swinging of the columns and the pivotal mounting allowing relative turning between the cables and connections to avoid chafing and wear of the cables. For these purposes the cables 31, 32 are provided with sleeves 34. fixed to the cables, the single strands of which may be threaded through the sleeves 34 and rings 33 and the sleeves are journaled in superposed upper and lower journal boxes 35, 36, as the case may be, which are rigidly connected together in vertically arranged pairs by suspension levers or posts 37, there being in the instance shown two such pairs at each column and each pair being provided with a split annular socket 38, one-half of which is integral with its lower journal box 36 and the other half of which forms a detachable cover 39. The journal boxes 35, 36 not only prevent chafing and wear of the cables but form a non-binding connection so as to always permit of free relative movement between the cables and journal boxes. The internal side walls of the sockets 38 taper inwardly and downwardly to wedgedly hold the opposite ends of connection cables 40, said ends being tapered to conform to the taper of the sockets by reason of the cable strands 41 being bent over the outside of a clamp-ring 42 through which the cable strands are passed. I

The connection cables 40 will be of appropriate lengths to suit the amount of dip of the supporting cables at the Various sections and are provided at their ends with core-pins 43 which may be driven into place before the clamp-rings 42 are placed in position as clearly shown in Figs. 8 and 9 and each core-pin is preferably provided with an annular shoulder 44 so as to form an annular ridge 45 around the cable and adapted to seat in an annular circumstantial groove 46 of the socket and its cover 38,

Each socket 33 is provided externally with a conical seat 47 and is pipe-threaded below the seat to receive a threaded clampnut 48 which fits the conical seat 47 and thereby wedges the socket halves together to securely hold the connection cable when the nut is screwed up. The ends of the connection cables 40 may be welded to the clamp-rings 42 and core-pins 43 to form a strong homogeneous structure, but such welding is not necessary to make a durable connection.

The connection-cables 40 are bent intermediate of their ends to form semi-circular loops 49 which are let into the channeled upper ends of the column 4, there being cover plates 50, bolted or otherwise removably secured to the columns, to close the sides of the channels.

By this construction of the suspender connections in conjunction with the superposed supporting cables 31, 32 it is clear that when said supporting cables are swung in arcs as they, at times, of necessity would be, under the influence of excessive wind pressure on the suspended structure; or directly by earth disturbances on the substructure piers, not shown, the lower cables 32 will tend to swing in a longer are than the upper cables 31 and such movement can only take place by lifting the suspended structure, the leverage of which through the suspension levers 37 thus militates against the swaying of the cables and minimizes and checks such swaying.

The upper cables 31 and lower cables 32 are connected respectively by transverse links 51 pivoted by bolts 52 or the like to the journal- boxes 35 or 36, as the case may be, so that the upper cables 31 are pivotally connected together in a horizontal series and will act in unison and the lower cables 32 are-pivotally connected together in a horizontal series and will act in unison and both the upper and lower series of cables are capable of independent transverse movement which will be against the weight of the structure that thus tends to keep the cables in vertical alinement against the swaying action tending to throw them out of vertical alinement as shown diagrammatically to an exaggerated degree in Fig. 6

For convenience in hanging the columns 4 at a predetermined height to bringthe vaand in case such disturbances and pressures lower journal boxes 36 of each pair with hanger-sleeves 53 which are pivotally connected by bolts 54 to screw-threaded eye bars 55 having turnbuckles 56 connecting them to eye-bars'57 that are reversely screwthreaded and that are in turn pivotally connected by bolts 58 to the'columns 4. From the foregoing it is seen that the decks are in pivotal relation to one another and to the supporting cables, that the deck-supporting frames and columns are in pivotal relation to the supporting'cables, that the cables of each series are in pivotal relation to one another, and that the sections are connected by expansion joints, but that aside from these pivotal relations and expansion joints the structure is longitudinally and transversely rigid, the combined effect being to minimize strains caused by moving loads, wind pressures, earthquakes and temperature changes; and it is also clear that the minimization of lateral movement resulting from wind pressure or other causes is effected at the cables by -the leverage ofthe structure acting to maintain the cables in vertical alinement'andis effected at the various decks by friction betweenthe deckrails and suspension-beams."

The action of'the bridgestructure under the influence of-the different causes tending Y to disto-rtit may be summed up as follows:

A moving load, such as a train of cars, passing across the'bridge will not deflect the cables su fiiciently to cause the deck in front ofthe load to rise in a wave-like undulation 3 because the columns and their suspenderconnections are spaced-apart fifty feet, more or less, along the superposed cables and are connected together by the longitudinally rigid deck-supporting frames. Physical disturbances of the cable-anchoring substrucf'so ture maysway the cables considerably, the lower cables through the longest arc and consequently out of vertical alinement, but the weight of thesuspended structure will immediately counteract this effect by its lever-like action drawing the cables into vertical alinementr These physical disturbances as well as wind-pressure will tend to produce lateral and vertical oscillations of disturbances and pressures are comparatively small, the oscillations will be neutral ized or entirely suppressed at the various decks by friction as hereinbefore'explained;

are comparatively great, the oscillations will not be suddenly arrested because the friction is reduced'by reason of the deck,- beams lifting faster than the suspenderbeams, and thus reducing "the friction. The effect of temperature changes on the difler ent sections is neutralized at each section by 1, A suspension bridge comprising superposed cables, suspension levers pivotally connected at their upper ends: to the upper cables and fulcrumed on the lower cables, and a deck connected to the lower ends of the suspension levers. I

2. A suspension bridge comprising cables, Suspender-beams swung from the cables, and deck rails swung from the cables in frictional engagement with and in shiftable relation to the Suspender-beams.

3. A suspension bridge having'means to check oscillations of the bridge, and means to reduce the amount of such check according to the degree of oscillation. 1 i

4. A suspension bridge having friction means to check oscillations of the bridge, and means to reduce the amount of said friction according to the *degree of oscillation. I

5. "A suspension bridge comprising sections having columns, there being expansion joints between adjacent sections at each column.

6. Ina suspension bridge, thecombination with the cables-thereof, of decks supported by the cables, and means pivotally connecting one deck to another.

7. In a suspension bridge, supporting cables, columns connected to the cables, and a deck in pivotal relation to the columns. V 8. In a suspension bridge, supporting ca bles, columns connected to the cables, suspension-beams and deck-beams ineccentrically pivoted relation to one another respectively and in pivoted relation to the columns, and deck-rails fastened to the deckbeams and in frictional engagement with the suspension-beams. 1

9. In a suspension bridge, supporting cables, columns connected'to the cables, transverse susp ension-beams pivoted to the col umns, deckfulcrum-beams connected to the columns, deck-beams pivoted on the fulcrum-beams lower than the pivoting of the suspension-beams, and deck-rails fastened to the deck-beams and in frictional engagement with the suspension-beams i 10. Ina suspension bridge, supporting cables, columns connectedv to the cables, transverse suspension beams pivoted tothe "columns, longitudinally extending deck-supporting frames connected to the columns,

beams and in frictional engagement with the suspension-beams.

11. In a suspension bridge, the combination with the cables thereof, of jointed columns pivotally connected to the cables, and a deck connected to the columns below the joints thereof.

12. In a suspension bridge, thecombina- .tion with the cables thereof, of superposed decks, and means connecting the decks to one another and to the cables and allowing the decks to move relative to one another.

13. In a suspension bridge, the combination with the deck thereof, of suspension means for the deck, and friction producing means operating during transverse mo-ve ment of the deck to check such movement.

14. In a suspension bridge, the combination with the deck thereof, of suspension means for the deck, means operating during transverse movement of the deck to check such movement, and means to reduce the amount of such check according tothe degree of movement.

15. In a suspension bridge, the combina tion with superposed cables, of boxes journaled on the cables and rigidly connected together, and decks flexibly connected to the lower boxes.

1 16. In a suspension bridge, the combination with superposed series of cables, of boxes journaled on the cables and rigidly connected in vertically-arranged pairs, links pivotally connecting the upper 'and lower boxes of one pair with the upper and lower boxes of another pair respectively, and decks flexibly connected to the lower boxes of the palrs.

17 In a suspension bridge, the combination with a supporting cable, of a column having a channel, a suspended-cable looped through the channel, and means connecting the ends of the Suspender-cable to the supporting cable.

18. In a suspension bridge, the combination with suspension cables, of a deck-sup porting frame, means connecting the frame to the cables, and a deck pivotally connected to the frame.

19. In a suspension bridge, the combination with cables, of a jointed deck-supporting frame, means connecting the frame to the cables, and a deck above and a deck below the frame joint, said decks being pivotally connected to the frame.

20. In a suspension bridge having superposed cables, the combination with such cables, of means rigidly connecting the upper and lower cables together, columns connected tothe lower cables, and deck-supporting frames longitudinally connecting the columns together.

21. In a suspension bridge, the combination with cables, of columns connected to the cables, and longitudinally extending decksupporting frames, said columns and frames being jointed in common.

22. In a suspension bridge, the combination with cables, of columns connected to the cables, and longitudinally extending decksupporting frames connected to the columns, said columns and frames being jointed in common.

23. I11 a suspension bridge, the combination with cables, of columns connected to the cables, and longitudinally extending decksupporting frames connected to the columns by expansion joints, said columns and frames being jointed in common by the expansion joints.

21. In a suspension bridge, a deck, superposed cables, and levers connecting the cables in vertically arranged pairs and connected to the deck and operated by lateral movement of the deck to lift said deck, the cables of adjacent pairs being pivotally connected to one another.

25. In a suspension bridge, cables, and a framework suspended from the cables, said framework comprising columns and suspender-beams pivoted to thecolumns.

26. In a suspension bridge, cables, and a framework suspended from the. cables, said framework comprising slotted columns and suspender-beams extending through the column slots and pivoted to the columns.

27. In a suspension bridge, cables, and a framwork flexibly connected with the cables, said framework comprising columns and suspender-beams pivoted to and transversely connecting the columns.-

28. In a suspension bridge, cables, and a flexible framework flexibly connected with the, cables, said framework comprising columns and suspender-beams transversely connecting the columns and pivoted thereto.

29. In a suspension bridge, cables, and a framework suspended from the cables, said framework comprising columns and suspender-beams transversely connecting the columns, and vertical deck-supporting frames longitudinally connecting the columns, said Suspender-beams and decksupporting frames being pivoted in common to the columns.

30. In a suspension bridge, cables, and a framework suspended from the cables and comprising jointed columns and comprising Suspender-beams transversely connecting the columns and comprising vertical rectangular frames longitudinally connecting the columns, said columns and Suspender-beams and rectangular frames being pivoted on an axis common to all of them.

31. In a suspension bridge, cables, columns suspended from the cables, suspenderbeams transversely connecting the columns, vertical rectangular frames longitudinally connecting the columns, deck-beams parallel to the Suspender-beams, longitudinal deckrails shiftably mounted on the suspenderbeams and fixed to the deck-beams, and a pavement supported by the deck-rails.

32. In a suspension bridge having longitudinally arranged beams, transversely arranged deck-beams pivoted to said longitudinal beams, suspender-beams pivotally mounted parallel to the deck-beams, and deck-rails resting partly on the deck-beams and partly on the Suspender-beams.

33. In a suspension bridge having sections, deck-rails for each section, means forming expansion joints between adjacent sections, and means forming expansion joints between the deck-rails of adjacent sections.

341. In a suspension bridge, suspenderbeams and deck-beams normally supported With their upper faces in the same horizontal plane, and means operated by Wind pressure or other force to raise the deckbeams relative to the Suspender-beams.

35. In a suspension bridge, suspenderbeams and deck-beams normally supported with their upper faces in the same horizontal plane, and means operated by Wind pressure or other force to raise the deck-beams relative to and faster than the suspenderbeams.

36. In combination, suspension cables, jointed columns hung from said cables, frames shiftably jointed to said columns, and a sectional deck supported by said frames.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 6th day of August, 1912.

ALLAN o. RUSH.

In presence of JAMES R. TOWNSEND, GEORGE H. HILES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

Corrections in Letters Patent No. 1,146,283.

It is hereby certified that in Letters Patent No. 1,146,283, granted July 13, 1915,

upon the application of Allan G. Rush, of Los Angeles, California, for an improvement in Pivotal Suspensi0n-Bridges, errors appear in the printed specification requiring correction as follows: Page 1, line 7 6, for the Word circumstantial read circumferential; page 6, line 98, claim 27, for the Word framwork read framework; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 24th day of August, A. D., 1915.

' J. T. NEWTON,

[SEAL] Acting Commissioner of Patents.

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