US1847341A - Rail way rail joint - Google Patents

Description

` March 1, 1932. A. HELLERMANN RAILWAY RAIL JoINI Filed sept. 12,` 195o Jnveniar:

25 than the width of the gap. v

have been'made on German railroads with the Patented Mar. l,` 1932 UNITED STATES PATENT ori-iceAv AUGUST HELLERMANN, ORFREIBURG, GERMANY, AssiGNoR io kTini FIRM GEsELI.-

soHAii'r FUR wIRTsCHArmLICHRN RAHNOBERBAU M. R. n., or FREIBURG, GERMANY l RAILWAY RAIL JOINT Application lied September 12, 1930, Serial o. 481,554', and in Germany September 22, 1926.v

This invention relates to railway or tramway rail joints in which an auxiliary rail is disposed at one side of the abutting ends of .the rails. Y

.There are already known butt joints for railway 'rails in which the auxiliary rail is rigid and in certain cases is elevated above the treadA face of the rails so as to prevent the des- .cent of the vehicle wheel inpassing over the '10 gap at ,the joint, or, rather, to a certain extent to lift the wheel over the gap. 'It has also been proposed asfdisclosed in my Swiss Patent 132,887 granted July 16, 1929 to make Y the auxiliary rail Iesiliently yielding inthe direction of the wheel pressure in order to take-up elastically the shocks resulting from passage of the wheelover the gap.` In order that this action of theresilient auxiliary rail may be ensured with wheel loads likely to be niet with in practice the tread surface of this resilient auxiliary rail was elevated somewhat above the tread surface of the rails alongside the gap, the length of the elevated portion of the auxiliary rail being only slightly greater Extensive tests joint construction above described and which is illustrated in my Swiss patent above stated and it was discovered that itis necessary that the resilient auxiliary rail must have such strength 'ofresili'ency that it is 'retained elevated beyond the surface of the tread wheels under the maximum permissible load. Only ifthis yconditionis preserved, the object of the invention can be achieved. Only in this within the region ofthe butt joint, the car wheels are exclusively carried by the. auxiliary lresilient rail. Y.

The known constructions of butt joints for railway rails have not been extensively adopted in practice because they have only to a small extent answered expectations.` The reason forthis is that inthe constructionand arrangement of such auxiliary rails assumptions have been made which arenot in corre: spondence with actual conditions in the passage of the wheels over the joints. It Ahas onlyk recentlybeen ascertained, as a resultof extensive experimental researohtliat 'the production of kshocks on passage over the jointy is less due tothe interruption of the track by the gap, than tothealteration ofthe static conditions at the joint relatively to the interf rupted rail and to-thealteration of the curve or defiection wave travelling with the wheel. The formation of this curve in the region of the joint depends essentially on tlienature of the-joint and the mounting of the rail ends'.

In every case by the alteration of the curve in the region of the oint there is brought about sudden alteration in the direction of movement of the wheel.' For example,in the case where the rail ends are mounted on the same double sleeper orrailtie which is lessyielding than the other sleepers or ties there results reduction of theipitch of the curve in front of the gap and elevation ofthe track, while behind the gap the track agaiiicfalls to the nori The consequence is that in front distance apart there is effected in front ofthe L gap under the load of the wheel increase of i the pitch of thecurve, that is lowering of the track. In consequence, the wheel-jumps with considerable shock on to the rail end beyond the gap and must beaccelerated in upward direction up to the level of the track, thus stressing severely this rail end. The length of the section of the tread surface which departs from the normal rectilinear track in consequence of the alteration of the curve or delection wave depends on the mode of mounting the rail ends and is the same for all wheel loads. lVith the load there is altered only the extent to which the tread surface oi' the rail departs from the normal rectilinear traclr. The length` of `this-section can be ascertained practically in ai very `simple manner by test for every style of bedding the rails.

The invention is, based on the recognition ofthe circumstance that in the regionof the gap increasedstressing of the rail'ends can only be avoided by maintaining the resi-lient auxiliary rail over the entire region of the section of? the: treadA surfacethat departs from the normal rectilinear track in supporting contact-with the wheel. For this purpose, according tothe invention, the construction and? arrangement of the resilient auxiliary rail?, whichinknown manner is elevated in nnloaded?v condition beyond' the-tread surface of themaiils, are such? that -the auxiliary-rail even under the-maximumpermissible load remains elevated above the tread -surface ot therails i'Ifr-tlie region of' this section. It has been found that this 'condition is fulfilled when the elevated portionlof the treadsuriace extends, in: the.' case Where' the rail endsare mounted, on ado-uble' sleepenup to aboutfmidway be- -t-ween'said sleeperandthe two adjoining sleepers, Vand; in the case where the-rail ends are mounted-"on two sleepers, for about the length of the distance between these two sleepers. Y'

either case not only the gap: but also the "entire: section ofthetreadt'ace of the rails which departs from th'e'rectilinear track is bridgedV by' the auxiliary rail. In theV case where the rail ends are mounted on two sleeper-s alteration ofthe direction-of movement ot the WheelsA canf bev almost entirely avoided., while inl the case where lthe rail ends are mounted'l on the same double sleeper the alterationof di'rectionj can be made so gradual that fthe' stresses. on the auxiliary rail due tothe inertia .of the wheel are very slight and liftingofthe wheel from the auxiliary rail is avoided. `fear in the neighbourhood of the gap canonlytake place on the auxiliary rail Whifcltcan be renewed if required with slight expenditure .of time and money.

Two embodiments ot theinvention are illustrated diagrammatically in the accom panying; drawings.-

Fig.v l :shows inside elevationV a `butt joint forrailway rails in which the raily ends are mounted freely as beams on two sleepers.

Fig-.vZ-shows also'in' sideelevati'on a butt joint forlrail-way railsin, which the rail ends are-mountedy onthe same double sleeper.

Fig. 3 is a section on the line 3 3 of Fig. l or Fig. 2.

lVith respect to both embodiments it is assumed that the vehicle wheel a represented by a chain-dotted circle moves in the direction or" the arrow hat is, from lett to right. rJ'Che rail end in front of the gap b is denoted c and the rail end in the rear of the gap is denoted c2. Under the load of the vehicle ce the rail suffers deflection in consequence of the yielding nature of the bed so thatthe tread surface beneath the wheel a assumes the form of a curve which is referred to as the deflection curve or wave. On the assumption that the yieldability of the' bed andthe stiffness of the rail are uniform over the entire length of therail, the deliection curve which travels with the wheel a has always the same form so kthat they lowestfpoint e of theI wheelv a d e- As, however, 1n'

downwards and then. a deviation` upwardsof the line f which represents the track 'ofthe wheel; while in the embodiment according to Fig. 2, in consequence of theresistance offered by the double sleeper /rcarryingboth. th'eraifl ends, the line 7 deviates upwards infront of thel gap and deviates downwards tothe normal level behind the gap;

Alongside the rail' ends the resilientauxiliary rail z' is mounted on blocks c and Z. The two ends of this resilient auxiliary rail are overturned or looped v and engage. the blocks 7c and Z in such wise that theportion in front vof the gap Z) is immovable inlbothl di'- rections, while the end behind the gapt can move in the direction of travel.. This is secured by forming the loop engaging the block lo with an upwardly directed 'lug causing the loopv to engage the block and thus prevent longitudinal movement of this end of the auxiliary rail. The auxiliary rail has such strength of tension or such resistance to depression that the tread face. of thisI auxiliary rail at .all times, and under all permissible loads is elevated above-the tread' face of the main rails for thelength of thesection g to such an. extent that it retains an velevated position above the tread -aces of the'main rails in the region of'this section gseven under themaximum permissible load. In the embodiment shown in Fig. l the elevated portion of the auxiliary rail extends for about thelength of the distance between the Atwo sleepers m and n, while in the embodiment shown in Fig. 2, the elevated portion of the auxiliary rail extends about midway between the double sleeper 7L and the two. adjoining sleepers 0 and p. The result is obtained that in the region of the section g at which the tread surface departs from the rectilinear tracl; in consequence of thel alteration of the deiiection curve the vehicle wheel is carried by the auxiliary ra-il z', so that in a sense the section g is bridged over it being unerstocd that the weight of the rolling stock causes a depression of the rail e' nearly to the level of the upper surfaces of the main rails.

I claim:

l. In a railway track structure, two abutting rails and an auxiliary rail disposed at one side of and closely adjacent the abutting l rail ends, the auxiliary rail having its upper surface upwardly curved and the middle portion of said surface extending above the tread faces of the abutting rail ends, the auxiliary rail being resiliently depressible under load but being of such resilient strength that the middle portion of the auxiliary rail remains elevated above the surfaces of the abutting.

rails under maximum permissible load of rolling stock.V Y

2. In a railway track structure. two abutting rails and an auxiliary rail disposed at one side and closely adjacent the abutting rail ends, the auxiliary rail being resilient and gradually increasing in thickness from its ends towards its middle, and the upper surface of the auxiliary rail being upwardly curved, the middle portion'of said upper surwardly curved, the elevated portion of the tread surface of the auxiliary rail extending to a point midway between the sleeper supporting the abutting ends of the rails and signature.

AUGUST HELLERMANN.

face extending above the tread surfaces of 2 the abutting rail ends, the auxiliary rail bef ing depressible under load against its resilience, but the resilience of the auxiliary rail being such that the middle portion of the auxiliary rail remains elevated above the surface of the abutting rails under maximum permissible load of rolling stock.

3. In a railway track structure, two abutting rails, sleepers disposed in spaced relation to the abutting ends of the rails, an auxiliary rail disposedy at one side and closely adjacent the abutting rail ends, the auxiliary rail having its upper surface upwardly curved and the middle portion cf said surface extending above the tread faces of the abutting rail ends, the elevated portion of the tread surface of the auxiliary rail being of a length approximately equal to the distance between said sleepers, the auxiliary rail being resilientV and depressible under load but offering such resistance to' depression` that the middle portion of the auxiliary rail remains above the surface of the abutting rails under maximum permissible load of rolling stock.

4L. In a railway track structure, two abutting rails, a sleeper disposed beneath the

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