CA2012143A1 - Rail pads and a method of upgrading railway track using such pads - Google Patents

Abstract

A B S T R A C T
HAIL PADS AND A METHOD OF UPGRADING RAILWAY TRACK
USING SUCH PADS
A pad which is suitable to be placed on a foundation for a railway rail and to have the rail standing on it, the pad being generally rectangular and comprising a web (1) from which, when the web (1) is lying in a particular orientation, protuberances (2, 3) project upwardly but no proturberances project downwardly, is characterised in that there are tens of the protuberances (2, 3) in the form of studs, each of which, except possibly at the edges of the pad, is completely surrounded by a portion of the web (1) which is free from protuberances (2, 3), the studs having convexly rounded tips and all the studs, except possibly at the edges of the pad, being substantially identical and of circular cross-section. The pa is further characterised in that is has two ears (8) projecting laterally froze each of two opposite edges of the pad to receive between them a part projecting upwardly from the rail foundation whereby the pad is prevented from moving along the rail. The pad is still further characterised in that it is no more than 6.5mm.
thick. Preferably, the pad is no more than 6mm. thick, and is desirably about 5.5mm. thick.
A method of upgrading a section of railway track using such a pad is also disclosed.

Description

~1 -R~L P~5 ~- A ~q~ o~ IJP~ N~ hWaY TE~ACK
~51 P~cc:ordin~ ~o a ~ir~t aspec:~ o'f the p~e E;~nl:
in~e~n~lon, th~r~e 1~ ~ro~ided a pa~l whloh 1~ ~3uit~ble. to S be ~laced c~n a fc1unda~ior ~or a r;~ilway r~il and -to h~e the ~ ndi n~ on lt, the pad ~einy ~nF~rally r~3ct~rlsu~a:r ~nd comprislng a we~ ~rom which, when the we~ i~ ly~ng horizontally, pro~uberanse~ proJeat upwardl~ ~ut no ~rc: tul~erance~ ~roJ ~ dowr~wardly, 10 c~h~racte~i~ed in th~t th~e ar~ t~ns o~ the protuberanc;~g in ~h~ ~o~n o~ s, eac~h o~ whic~h, exce~ po~bly a-t tha edg~s ~ the p~d, 1~ c:ompletely su~round~d by a ~ortion o~ the web which i~ fr~3e ~rom p~otub~ncs~ ~ the3 ~tu~ hav~ ng ::on~rea:ly x~o~lnde~d 1~ip~
15 and ~ h~ ~tud~, e~c:ept pe~s~ibly at ~ch~ odg~3 o~ th~
~ad, bein~ t~ en~ c~l ~nd of oircula~
cr~8~-s~ion an~ rther c:h~ rl~ in ~ha~ ~he pad h s two e~rg p~oj~cting latera~ ly ~om eaoh o~ two oppQ~ite ~d~e~ o~ 1;he p~d to re~ive~ b~we~n them a 2û p~rt pro~e~tlr9 upwE~r~ly ~rom th~ r~ll foun~a~ion w~r~by the pad is pre~vent~Cl x~m mo~ring ~lon~ th~ rall ~nd ~ti~l ~urther ch~r~at~rised ln ~h~t the pad i3 no more than ~ hick~
P~e~rably, a pad ~mbody~ ng ~he ~lr~ a~p~3c~ o 5 t~e pre~n~ lnvenkion ~ no m~re that ~mm~ ~hiok, ~nd ds~ ly e~bout 5 ~ 5mm. th~ ck .
It :ls al~o pr~erabl~ ~he~t ln a pad em:t~odyln~ th~
~ir~t a~pe~ o~ th~ pr~sent i~3ntion ~h~3 studs ar3 in parali~l r~ws a~nd in p~r~ l aol~amn8 lncliII~d }:~y an 30 aau It~3 an~ o ~h~3 rc~wa, In a ~ G~:L~ ho ~irs~ a~p~3cst of th~ pre~ t inven~on it ~ de~ bl~ ~h~, exc~l; at th~ ~3dg~3~ o~
~h~ p~d, ~ h ~tua ~ su~ounde~ ~ ~lx o~h~r ~uds ~one o whioh ~ ~t ~ t~no~ ~rom lt ~r~a~ than the 3~ thicknes~ o~ th~3 ~tudt Pr~f~r~l:ly, ~n ~ p~d em~o~ying ~he fir t a~pecst 2~2~

o~ the pr~s~3n~ invention ~he ~tud~ a~ e~h O~e two oppo~ite. ~3dg~i3s of ~he pad are wiq~x, i n a ~irectlor ~rom orle o~ ~aid e~es ~o ~he oth~3r, th~n th~3 ~t~d3 n~rer thEa centre o~ the ~ad.
I:~E-101413~ di~olo~es 2~ p~ which 1~ ~ui~abl~ tO ~e pl~cec~ on a founda~lon for a r~$1way rail arl~ tP have ~he ~ail ~t~ndin~ on it, ~he p~ ein~ ~nerally re~:tangular and compri~ln~ ~ we~ ~rom wh~ c~h, wh~n ~he we~ i~ lyi2l~ in ~ pax~l~ul~r oxi~n~t~ on, protu~3~rancs~
10 pro~ upwardly ~u'c no pro~ub~ranc~ ~roJ ~ct downwaxdly. How~ver, th~ pro~u~r~nc:e~ Oll the pad disclo~ed in DE-1~14139 aræ very :~w ~nd the~ ~re l~r~e arl~ w; ~ly ~pao~d ap~rt ~nd ~r~ ~oi~ed togeth~a~ b~7 aro~pi~ce~ whic:h ~ln~e~irably limit the~ æibility of 15 the p~d .
According to a ~eoon~ ~p~c~ o~ ~he praserl~
inve~tion, ~her~a ls provid~d a me~hod o~ up~radin5~ a 3f~ ion ~:~ r~llw~y trac;k in which a r~il st~nd~3 ~n ~
first pa~ whic~h 1~ e~ on a oun~&~ion, in whic:h m~thod 20 th~ pad i~ rl3pl~d b~ a ~czorld ~d embo~y~ ng tha ~ t a~pc:cst olq ~h~ pre~ent 1 nventlon and o~ ~ubs~an~ lly th~ same thlckne~s ~ when aompr~ 8e~, as ig ~he f $rst pad, whe~ con~pr~3~d, or no m~re ~h~n a~ut lmrn.
thiok~r .
~5 ~efer~!3nc:e will now ~e m~, hy w~y of axample, to the ~ccomp~n~in~ draw1ngs, in whic:h:
Fiçlu~e 1 show~ a pla~ viebr o~ a rail ~1 em~od~in~
the~ asp6lct o~ th~ en~ inv~n~on;
F~gur~ 2 ~how~; a ~d~ vl~w o~ ~he r 11 p~ when 30 ~i~w~3d ax indi :s~t~a ~y th~ ar~ow ~ Figure l; an~
~ ur~ 3 show~ 5 ~ec~tlonal ~lew o~ r~r ~c:ala o~ p~t o~ ~che~ ~il pad whs~ ~iew~d a~ in~lc~3t~l by th ~rrow II in Figure 1.
The p~ stre~ n th~ dr~win~ aonsis~ o 35 ~:1 n~le mouldin~ oP pol~rethar~e ~n~ an~rally ~e~tanç~ul~r ~5 ~e~3n ln ~larl vi6~w. It cor~ ts oE a ~enerally re~tarlgular we~ 1 2. 5m~l~ thlc:~ h~ving many protube~nc:e~ in tha ~orm o~ ~tuds 2 o ~iraular ~osæ~s~ lon ~nd ~ds 3 of elong~e ~ros~ eo~ion on on~ ~ce 4 o~ ~he wsb~ On th0 op~osit0 ~ 5 o:~ th~
5 w~}~ ther~ are no prot~l: erE~nce~ and no ~eo~s~s . ~he dlstance ~ro~ th~ e 5 ~o the l:ip~ of th~ ~tud~ 2 and 3 i~ 5~5mm..
~he ~3~ud~ 2 h~v~ a di~meter u~ ~ . 75rtun. at th~lr ~lp~ and ~ sli~h~ly l~rg~r dlame~;er at their roo~
bec:~u~;e their ~lan r~ lnc:llned ~y ~n an~la X o~ I
ab~ut 5~ ~o ~h~ n~rmal ~ to th~ w~ ha tip~ o~ ~ha s~ud~ ~ ~re ::on~rex wlth ~ r~dius o~ 24mm.. The ~ud~ 3 have A fl~t ~rea 3~ h~ir t~p~ and a ~on~7~xly cu~ved area 3~3 at the ~id~ o khei~ tips n~er ~h~ ~erltre o:~
th~ p21~. rrhç~ ~tuds ~ ara ~r~n~ d ln ~olum3l~ whic:h ~re3 ve~t:iaal in Figur~ ~ ~nd ln ~ow~ whi ~h ~re lnollr~d b~
an aou~e ~ngl~ Y ~o tha ~::oluuDn~. Th~r~ ~r~3 ~igh~
colun~n~ each w~h el~ven ~tuds 2 and one -e~ud 3 at e ch end o~ tha c:oluT~ n~ tw~n ~ho ~ oolumns, s~3ven column~ e~ch ~on~ist~ n61 o~ tw~lv~ ~tud~ ~ . The l?itches he ~tuds ~ in ~h~ ~olu3nns art3 llmm. and the c:olum th~m~el~e~ h~re a pit~h of 17-.7mm., m~3~sure~
perp~ndl~;ul~rl~ to the aolumn~ Wh~3rs ~vo ~tuds 2 ~
or~ 3tud 2 arld ~ne ~ud 3 in a~y one colum~ h~ve ~h~ir 2~ r~o~ ~dJoinin~ onc3 ~nother th~e 1~ a ra~lius R o~
~5~mm. .
:; At ~aoh o~ two ~ poslt~ ed~es c~f the w~ th~ar~ i~
~ r~glo~ 7 wh~r~ ~he we~ thickn~s ls 4mm. and ~om eQ~h ~ on 7 th~re ~?ro~ ~t ~wo ~a~ 8 c~ the ~ame thio~o a~ th~ r~gion 7, tha int~nt~ vn l:~ln~ ~h~
41i~-r~ nln~ m~mbe~ for a so~ d P-~ oll~ or an is to lie partly betor~ oh two adJ ~c:en~
:; e~r~ ~ whe~eby ~ny tond~ F æcr th~ pa~ ~o movs alon~
rail i8 Op~OB~
A E~d unbo~lng ~h~3 ~ir~t asp~o~ E the pre~en~
.~n~r~anti~n ~an i~ol~te ~he rail oundatic~n from ~pproximat~31y ~6 o~ ~ 40kHz vibra~o~ ~orc~ appll~ ~o the ov~rlyin~ r~ll.
It ~hould be notad that, althous~h ~he pad de~cribed wlth r~r~ e tc: ~h~ Fl~ures ls made o 5 ~ uxeth~n~, a pisd ~m4c~ylnç~ ~he f trst asp~o~ the pr~3sent inventlon could be m~dQ o~ an~ r suit~ly ro~ust o~ h~rden~d mater~ u~h a~ polye~ter, pol~ethylen~ o~ ru~r.
In som~3 ciraums~arlc~e~ i~ may be de~;irabl~ to 10 s~ure th~ ~a~ 5 o~ l:he web, by a su~bl~ ~dhe~iva, to a r~ e~t o~ a ooncrs~e ~il foundatiorl, or sx~mple 8 sla~p~ ~onf~is~ing o~ a ~o~cre~e ~am UpOtl whic~ wo rai~s ~t, or a b~oak UpOI~ w~:iah only of~e ~il r~a~3t~3 and ormin~ part o~ a ~lee~r svmpri3ing ~wo 1~ ~locl~ join~d ~0~ her by a ~te~ a~) or a ls~n~
~l~b o~ GOS~G~e~;~! e~t0n~n~ Qlon~ the railwa~ ac:~cO
On~3 of ~hEa re~on~ wh~ 1~ may ~ eslr~ O ~ecur~3 th~3 paa by ~n i~dh~ e i~ t~at ~hi ~ prevan~ 3nd, wh~h 1~ ~ppli~d tO th~a ~unnin~ ~ur~e~ o~ th~ rail, 20 ~rom pr~3netr~1ng batwclerl t~h~ pa~ and th~ cor~c;ret~3 ~leepar, wh~re i~ c:all c~u~ aJ3ra~10n o:~ ~o~h the ~d ~nd the ~ pex.
It ~ o pos.~le ~ R~3~U~e ~hl3 1 llu~ te~ pad by all adhe~lv~ to a ~ el r~ ay sl~3ep~r, Furth~rmo~e 2S an ~nti~ely dl~:~e~ent pa~d, b~ havln~ ~r~otuberan~:e3 a~or r~c:e~a~ on its upper fac~, ku~ not on l~c!æ lower ~ace~ m~y ~l~o h~ low~r ~ac6~ ~eaur~d by an ad~e~ 3 tv a c~onar~t~ ~r st~31 r 11 oundatlon.
P Cl~ cor~inç~ ~ th~3 ~lr~t ~ t o~ tho pre~ent 30 ~nvEan~lon ~r~ pref~r~ly ~amploy~d lr~ ma~ho~ ~nbodyls~
th~ o~d ~ec~ o ~h~ p~ lnv~entioa~, ~8 ~i~l now b~3 ~le~cr~be~.
In soma c;~raUm~anc:e~ deaslr~le ~o upg~r a ~ ion c~ r~ilway ~r~k, so ~ ~o a~low th~t ~Bo~ior 3~ to wlth~nd h~.vi~3r loasl~, ~or e:Kampls ~3o~u~e a~ the w~3h tO U~ h~3~vls~ rall~y vehlcl~s a~ o~ vehicles J ~ ~ 3 tr~vellin~ at ~ster speed~.
AC ::orairl~ to the ~e~ond asp~3r~ of the pr~3~t i~ven~ion, f~r~ly the. means ~a~ in~ Ith~ r~il to ~he ~oun~lati~n ara rele~ed. ~ypi~lly, ~he rall f~tRning 5 me~ns ~:ompri~e rail alip~, such ~ a P-R clip or ~
e-clip, an~ to rel(laas~ ~h~ r~ rom r~ ntion by such C;~ th~ clips ~r~ t~ t~d from ~pec~i~e c:lip-rE~taln~ng memb~ e~d~3d 1~ r otherwise attached ~o, th~ :ca~l ~ounda~lon.
When ~;h~3 rail h2~ ba~ll rql~ d, ~he rall pad that had l~e~rl lyin~ ~a twe&n i~ ~nd the~ r~il ound~ n i~;
~emov~d and i~ r~ap~c:ed ~y ~ pad, e~odyln~ ~he firs~
a~e~ 4~ the prea~an~ ~n~en~on, whlc;h is o~
sub~t~ntl~lly th~ ~me thi~sn~R~, when sompre~d, a~
l S thQ E3~d that it ~ rsplac~ , wh~rl th~t p~d is ~;ompres~ed, os no mora than e.~ou~ hicker~ S~nc:e pad~; eTI~bodyin~ th~ ~lrst a~p~ct o~ ~he preser~t in~3ntion haYe pro~ul: eranass ox~ on~ one ~ac;~
E~0S8~bl~3 to manu~ ure a pad whi~ bet~ar i~olates ~he ~0 our~ati~n ~om dyrlam~c ~or~!e~ ~h~n the pad which it is to repl~ u~ i~ at the ~ame time no~ subs~alltially tn~cker than ~hat pad. By r~pl~ ln~ tho i~ pad by suc;h a p~l, it I Y po~slbl~ ~o re~use th~ ~il allps, whlc:h ~ra pr~viouæly ~t~ d so as to rel~a~3 th~
~5 rail, to ~cure ~h~ ra~l ono~ a5~aln ~0 ~hla rall 0und2tio~, wi~hou~ the distorti~ o~ the ali~ on ~rivlns 7 them into po~itlcm ~3ln~3 ~30 ~rea~ that ~h~y ~x~ar~ ~o hlgh a forc:e on ~h~
Slr~ p~ u~d ln ~llway ~r~oJc ~o whl~h m~hod~
30 em~o~y~nS~ ~h~ ;on~ ~pe~ of khe pr~en~ ln~en~ion m~y ~e ~pplisd i~re ~m3rzl11y ~5tmn. to ~ hic:k, an~ ~re ty~ 505m~ n o~arall thiGkIl~ass~ wh~
c:~ml?r~Rd, ~d~ embo~n~ th~ :Fir8t a~ec~k o~ ~e prss~nt inve~ntion ~re, wh~n ~om~re~;~ed, no mo~e than ~5 ~ 5n~, thick, ~e pr~ r~ly no more th~Tl 6mm. thick, ~nd ar~ d~irably ~out 5~ Smm. thiClc.

Claims (12)

1. A pad which is suitable to be placed on a foundation for a railway rail and to have the rail standing on it, the pad being generally rectangular and comprising a web from which, when the web is lying horizontally, protuberances project upwardly but no protuberances project downwardly, characterised in that there are tens of the protuberances in the form of studs, each of which is completely surrounded by a portion of the web which is free from protuberances, the studs having convexly rounded tips and all the studs, except possibly at the edges of the pad, being substantially identical and of circular cross-section and further characterised in that the pad has two ears projecting laterally from each of two opposite edges of the pad to receive between them a part projecting upwardly from the rail foundation whereby the pad is prevented from moving along the rail and still further characterised in that the pad is no more than 6.5mm.
thick.

2. A pad according to claim 1, wherein the pad is nor more than 6mm. thick.

3. A pad according to claim 1, wherein the pad is about 5.5mm. thick.

4. A pad according to claim 1, in which the studs are in parallel rows and in parallel columns inclined by an acute angle to the rows.

5. A pad according to claim 1, in which. except at the edges of the pad, each stud is surrounded by six other studs none of which is at a distance from it greater than the thickness of the stud.

6. A pad according to claim 1, in which the studs at each of two opposite edges of the pad are wider, in a direction from one of said edges to the other, than the studs nearer the centre of the pad.

7. A method of upgrading a section of railway track in which a rail stands on a first pad which lies on a foundation, in which method the pad is replaced by a second pad according to claim 1 and of substantially the same thickness, when compressed, as is the first pad, when compressed, or no more than about 1mm.
thicker.

8. A method according to claim 7, in which the said second pad is a pad according to claim 2.

9. A method according to claim 7, in which the said second pad is a pad according to claim 3.

10. A method according to claim 7, in which the said second pad is a pad according to claim 4.

11. A method according to claim 7, in which the said second pad is a pad according to claim 5.

12. A method according to claim 7, in which the said second pad is a pad according to claim 6.