US2538443A

US2538443A - Railway sleeper

Info

Publication number: US2538443A
Application number: US615984A
Authority: US
Inventors: Delvaux Jules Arnold Marie
Original assignee: Frankignoul Pieux Armes
Current assignee: Compagnie Internationale des Pieux Armes Frankignoui SA
Priority date: 1944-08-25
Filing date: 1945-09-13
Publication date: 1951-01-16
Anticipated expiration: 1968-01-16

Description

Jan 1, 1953 J. A. M. DELVAUX RAILWAY SLEEPER Filed Sept. 13, 1945 Patented Jan. 16, 1951 RAILWAY SLEEPER Jules Arnold Marie Delvaux, Brussels, Belgium, assignor to Compagnie Internationale des Pieux Arms Frankignoul, Liege, Belgium Application September 13, 1945, Serial No. 615,984 In Belgium August 25, 1944 Section 1, Public Law 690, August 8, "1946 latent expires August 25, 1964 8 Claims. l

My invention is for improvements in or relating to hinged ties of concrete or the like particularly adapted for railway use although they can be equally well employed with all their inherent advantages as constructional girders for other purposes. 7

With the object of. remedying the deformation of concrete and the like ties and to impart thereto a certain degree of flexibility, it has already been proposed to form a tie of a number of transverse elements or sections connected by one or more metal tie rods arranged to effect a longitudinal clamping action. On flexures of such a tie under the effect of the service loads, the edges of the successive elements wear away rapidly in consequence of the very large local compression stresses, thus producing a premature destruction of the tie, the elements of which have undergone such frequent relative transverse displacements. 1 Furthermore, the flexibility of these ties was only negligible, the flexibility afforded by the tie rods in ordinary steel and moderately tensioncd was insufficient to permit the elastic flexure of the tie with the amplitude provided for by official regulations, and giving furthermore rise to excessive fatigue of the tie rods. 7

The invention has for its object to provide a girder or tie capable of undergoing practically without fatigue repeated fiexures of the desired amplitude, whilst ensuring the perfect elastic return of the tie to its normal position, as also its stable equilibrium in this position, so that permanent deformations of the girder need not be feared. nor the local destruction or' transverse relative displacement of its elements.

Acording to the invention, the object is attained by adjacent elements of the girder or tie which must be hinged together to bear normally one on the other by local members of contact which are provided on the adjacent faces of the elements of the tie and form for each direction of fiexure provided for by the whole of the said adjacent elements of the tie, a hinge located externally of the axis of the stress developed by the longitudinal reinforcement placed under preliminary tension, which hinge is constructed in such manner as to be able to support the total stress of compression exerted on the elements of the tie. The adjacent extremities of the girder elements are preferably provided with projecting metallic plates which are embedded in the mass of the said elements, these plates being respectively provided with hollows and projections mutually fitting together and forming a hinge.

The number and the arrangement of the hinges may vary according as to whether the tie is ina tended to undergo flexures in one or several directions. For each direction of flexure, there may be provided two hinges located on each side of the central axis of the force exerted by the lonrelative movement of rotation of tie elements is to be initiated for a single effort or for different efforts according to the direction of the flexure. The hinges also which correspond to different directions of flexure may be located at equal or unequal distances from this axis. Whatever'may be the end section of the tie elements, it is sufficient to bring the hinges more or less close to the said axis to initiate therelative rotation of the tie elements under the effect of .a more or less feeble effort.

In the case of flexures of a tie, it is the reinforcement which furnishes theflexibility ensuring the return into the position of rest of the sensation. This reinforcement may be constructed in any suitable form, for example, it may be constituted by one or more longitudinal tie rods supported on the and elements of the tie. According to the invention, this reinforcement may be constructed of steel of high resistance and be placed under great preliminary tension, so as to be able to support without unallowable fatigue the repeated lengtheni'ngs and shortenings resulting from the flexurcs of v the tie, or a spring or the like may be'interposed between at least one extremity of the reinforcement and its support so to cause a yielding displacement of the desired amplitude, practically doing away with the fatigue of the reinforcement which may then be made of a less elastic metal, for example a semi hard steel.

' Other features and advantages of the invention will appear from the description of some examples of embodiment which will be her'einafter'described.

The invention will be hereinafter more particularly described with reference to the accompanyingdrawings, in which: Figure 1 illustrates in plan a railway tie constructed according to the present invention with I the reinforcement removed;

Figure 2-illustrates in section on-the line II-I1 of Figure 1, a railway ti constructed according to the present invention, with the rein orcement in position;

broken line VI-VI of Figure 5, together-with a section of the adjacent element of. the tie...

Referring to the drawings, the tieillustratedin Figures 1 and 2 comprises two raised end: elements I and an intermediate element2 which are made of reinforced concrete or the likeandl'arexcon nected together by a longitudinal r-einforcei'nentplaced under preliminary tensions. The reinforce= ment may comprise one or more tie 1ro'ds 3 :exw

tending freely through longitudinal recesses 4 and 5 formed in the elements I and land air chored with respect to'the end elements I of the tie: to which they arese'cured for example by -m'eanscf nutsffi'and washers'l. Each tierod 3 may comprise a single bar or a bundleofsteel wires; In the example illustrated, aspring B is' interposed between 'th e extremity 'of' "each tie rod and the corresponding'extremityof the tie; which permits the tie-'rodsto be formed ofsemi-h'ard steel whilst'ensuring that'the rod-yields sufficint-lyi' Tl'lesprings 8 mayin' particular be constitutedby elastic washers in current use on rail-' ways.

The elements I and 2 of the'sl'eeper are con nected together accordingto the invention by hinged articulations 9, two embodiments of which are illustrated in the'drawin'gs.

In the example .illustratedinFigures *3 and 4, each" articulation. comprises 'two metal plates 10,1 I embedded respectively in a. raised .end element I and inith'e'intermediate element 2. One of the plates is provided'with' semi-circular ribs l2 which fit into correspondinggrooves 1350f the other. plate. Th'eefictofthe tie rods 3 isto draw the ribs l2into the. grooves it, so .that the assembly formed bythe raised endelementsand the intermediate element is maintained Iin..stable equilibriuma Ona flexure of. the .tiethe sections 1, 2. rock one with respect to the other about-one orlthe other of the ribs -l2 according.tothedirection of the. stress; and-return into position under the action ofthe tie-rods-as-soon astheapplied stress is releasedt- There is thus produced a tiewith doubl hinged articulation? and yieldingreturn; It is obviously necessary to-leave between the parts oftherplates lfl,- located outside the hinges;- a -spac'e sufficient to permit the: relative angular movement ofthe elements I and-'2 Whatever 'may be the direction of the. flexure, the-whole of theenergy. stored in the reinforce ment by reason of the elongation of the tie rods orfthe like: and/or of the compression of. the spring. onsprings Biis availableito ensure the im mediate yielding -'return1;off'the;t-tie into? its position of equilibrium. Inlthe' modification;illustrated iniFigures. 5 and.6; thewarticulationis "formed: by "two? plates l4, l5 which are embeddediin:theielementsfil and and' hav'e each four semi-spherical recesses [6911 in whichare 1ccated fourballs 18.. These latter may be simply placed in the recesses 16, l l or they may be'fiked to on'e-of' the plate-Sand located 5 freely in the corresponding recesses of the other pl'atee The whole *is kept "-iii' compres- 51011. y a tie rod l9 placed in tension -which ex 4 tends freely through a bore 20 made in the tie elements and the plates M, [5.

According as they are working in horizontal or vertioal..pairs,.-the four balls 18 form horizontalor vertical hingespermitting the relative hinging of the elements I and 2 in the vertical on horizontal direction. The same result would be obtained by four hinges similar to those shown by Figures 3 and 4 and formed by ribs and grooves arranged in a square or rectangle.

Themodification according to Figures 5 and 6 is-particularly useful for a railway tie which, apart from the vertical resultants of the differentiat loadstransmitted to it by the two lines of -rails would have to withstand differential horizontalstressesdue, for example, to bra-king actions;

The number of hinges of the articulation may be in'creased in such manner that for a tie or girder intended to undergo flexures in difierent directions; there is a'hinge for each direction of flexure;

Whatl claim is:

1. An articulated'tie comprising a plurality of separate elements'arranged in enclto end relation, a pair of mutually facing rigid contact members on the adjoining'ends of at least two adjacentelements, longitudinal reinforcement means-fixed relative'to the end elements of the tie and-extending freely through all of said elements and contact members and arranged under tension to. apply a compressive force lengthwise 0f the assembly, and hinge means for-.eachrdirection of-flexure between the contact members of'each pair ofxmutually facing contact members; each hinge means being arranged external-lyof theaxisof the reinforcement means son-that each hinge means permits flexure of theadjacent tie'elements about a; determined corresponding distinct. axis located externally of and perpendiculartouthe axis of the reinforcement means, and the adjacent tie elements and contactmembersbeingslightly spaced from each. other .ati-pointsexternally of each hinge means.

2: An articulated tie as claimed in claim 1, wherein each hinge means is constituted by a portion. of .one of-:the--members of each pairof mutuallyfacing contact members fitting into'the adiacentfacing contact member.

3.-A-n articulatedtie asclaimed in claim 1, whereineach-hinge means-is constituted bya projection on one-'of-the'members of each pair of mutually facing contact members, engaging inra: correspondingly shaped depression of the adjacent con-tact member.

4. An'articulated tie as claimed in claim 1, wherein. eachhin-ge means comprises a metallic semi-:cylindrical rib projecting from one-of the contact members and the other related contact member havingagroove ofcorrespo'nol-ing configuration; provided. in the adjacent face thereof for receiving the rib.

5. An articulated tie as claimedin claim 1, whereinveach hinge means comprises two pairs ofumutually; facingsemi-spherical recesses providediin.tWo-.-adjacent*contact members and a ballloflhigh:resistance material located in each pairlof mutually facing recesses.

6:: Anarticulated tie as claimed in claim' 1, wlfereinzeach' hinge means comprises two semi spherical recesses provided in each of the'ad jacent'icontact members and two balls located in-said rec'esses, and each ball being fixedin one of the latter recesses.

7". An artic'ulated. tieas claimed in claim 1,

having hinge means of the same articulation of the tie arranged at difierent distances from the axis of the reinforcement means. V

8. An articulated tie comprising a plurality of separate elements arranged in end to end relation, a pair of mutually facing rigid contact members on the adjoining end of at least two adjacent elements, a longitudinal reinforcement rod fixed relative to the end elements of the tie and extending freely through all of said elements and contact members and arranged under tension to apply a compressive force lengthwise of the assembly, and hinge means for each direction of flexure between the contact members of each pair of mutually facing contact members, each hinge means being arranged externally of the reinforcement rod so that each hinge means permits flexure of the adjacent tie elements about a determined distinct axis located externally of and perpendicular to the reinforcement rod, and the adjacent tie elements and contact members being slightly spaced from each other at points externally of each hinge means.

JULES ARNOLD MARIE DELVAUX.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS