FMVSS 571.202 Standard No. 202

47449CFRCh.V(10–1–03Edition)§571.202[62FR16725,Apr.8,1997;63FR28,Jan.2,1998;63FR41464,Aug.4,1998;63FR45965,Aug.28,1998;64FR7140,Feb.12,1999;64FR69671,Dec.14,1999;67FR41354,June18,2002;68FR51711,Aug.28,2003]EFFECTIVEDATENOTE:At67FR79439,Dec.23,2002,§571.201wasamendedbyremovingthedefinitionofmotorhomeinS3,Defini-tions,effectiveDec.27,2004.§571.202StandardNo.202;Headre-straints.S1.Purposeandscope.Thisstandardspecifiesrequirementsforheadre-straintstoreducethefrequencyandseverityofneckinjuryinrear-endandothercollisions.S2.Application.Thisstandardap-pliestopassengercars,andtomulti-purposepassengervehicles,trucksandbuseswithaGVWRof4,536kgorless.VerDatejul14200309:13Dec08,2003Jkt200207PO00000Frm00474Fmt8010Sfmt8010Y:\SGML\200207T.XXX200207TER08AP97.009/GPH475Nat’lHighwayTrafficSafetyAdmin.,DOT§571.202S3.Definitions.Headrestraintmeansadevicethatlimitsrearwardangulardisplacementoftheoccupant’sheadrelativetohistorsoline.S4.Requirements.S4.1Eachpassengercarshallcom-plywithS4.3.S4.2Eachtruck,multipurposepas-sengervehicleandbuswithaGVWRof4,536kgorless,shallcomplywithS4.3.S4.3Performancelevels.Exceptforschoolbuses,aheadrestraintthatcon-formstoeither(a)or(b)shallbepro-videdateachoutboardfrontdes-ignatedseatingposition.Forschoolbuses,aheadrestraintthatconformstoeither(a)or(b)shallbeprovidedforthedriver’sseatingposition.(a)Itshall,whentestedinaccord-ancewithS5.1,duringaforwardaccel-erationofatleast78m/s2ontheseatsupportingstructure,limitrearwardangulardisplacementoftheheadref-erencelineto45°fromthetorsoref-erenceline;or(b)Itshall,whenadjustedtoitsfullyextendeddesignposition,conformtoeachofthefollowing—(1)Whenmeasuredparalleltotorsoline,thetopoftheheadrestraintshallnotbelessthan700mmabovetheseat-ingreferencepoint;(2)Whenmeasuredeither64mmbelowthetopoftheheadrestraintor635mmabovetheseatingreferencepoint,thelateralwidthoftheheadre-straintshallbenotlessthan—(i)254mmforusewithbench-typeseats;and(ii)171mmforusewithindividualseats:(3)WhentestedinaccordancewithS5.2,therearmostportionoftheheadformshallnotbedisplacedtomorethan102mmperpendicularlyrearwardofthedisplacedextendedtorsoref-erencelineduringtheapplicationoftheloadspecifiedinS5.2(c);and(4)WhentestedinaccordancewithS5.2,theheadrestraintshallwithstandanincreasingloaduntiloneofthefol-lowingoccurs:(i)Failureoftheseatorseatback;or(ii)Applicationofaloadof890N.S5.Demonstrationprocedures.S5.1CompliancewithS4.3(a)shallbedemonstratedinaccordancewiththefollowingwiththeheadrestraintinitsfullyextendeddesignposition:(a)Ontheexteriorprofileoftheheadandtorsoofadummyhavingtheweightandseatedheightofa95thper-centileadultmalewithanapprovedrepresentationofahuman,articulatedneckstructure,oranapprovedequiva-lenttestdevice,establishreferencelinesbythefollowingmethod:(1)Positionthedummy’sbackonahorizontalflatsurfacewiththelumbarjointsinastraightline.(2)Rotatetheheadofthedummyrearwarduntilthebackoftheheadcontactsthesameflathorizontalsur-faceinparagraph(1).(3)PositiontheSAEJ–826two-di-mensionalmanikin’sbackagainsttheflatsurfaceinS5.1(a)(1),alongsidethedummywiththeh-pointoftheman-ikinalignedwiththeh-pointofthedummy.(4)EstablishthetorsolineofthemanikinasdefinedinSAEAerospace-AutomotiveDrawingStandards,sec.2.3.6,P.E1.01,September1963.(5)Establishthedummytorsoref-erencelinebysuperimposingthetorsolineofthemanikinonthetorsoofthedummy.(6)Establishtheheadreferencelinebyextendingthedummytorsoref-erencelineontothehead.(b)Ateachdesignatedseatingposi-tionhavingaheadrestraint,placethedummy,snuglyrestrainedbyaType1seatbelt,inthemanufacturer’srec-ommendeddesignseatedposition.(c)Duringforwardaccelerationap-pliedtothestructuresupportingtheseatasdescribedinthisparagraph,measurethemaximumrearwardangu-lardisplacementbetweenthedummytorsoreferencelineandheadreferenceline.Whengraphicallydepicted,themagnitudeoftheaccelerationcurveshallnotbelessthanthatofahalf-sinewavehavingtheamplitudeof78m/s2andadurationof80millisecondsandnotmorethanthatofahalf-sinewavecurvehavinganamplitudeof94m/s2andadurationof96milliseconds.S5.2CompliancewithS4.3(b)shallbedemonstratedinaccordancewiththefollowingwiththeheadrestraintinitsfullyextendeddesignposition:(a)Placeatestdevice,havingthebackplandimensionsandtorsoline(centerlineoftheheadroomprobeinVerDatejul14200309:13Dec08,2003Jkt200207PO00000Frm00475Fmt8010Sfmt8010Y:\SGML\200207T.XXX200207T47649CFRCh.V(10–1–03Edition)§571.203fullbackposition),ofthethreedimen-sionalSAEJ826manikin,atthemanu-facturer’srecommendeddesignseatedposition.(b)Establishthedisplacedtorsoref-erencelinebyapplyingarearwardmo-mentof373Nmmomentabouttheseatingreferencepointtotheseatbackthroughthetestdevicebackpanlocatedin(a).(c)Afterremovingthebackpan,usinga165mmdiametersphericalheadformorcylindricalheadformhavinga165mmdiameterinplanviewanda152mmheightinprofileview,apply,per-pendiculartothedisplacedtorsoref-erenceline,arearwardinitialload64mmbelowthetopoftheheadrestraintthatwillproducea373Nmmomentabouttheseatingreferencepoint.(d)Graduallyincreasethisinitialloadto890Noruntiltheseatorseatbackfails,whicheveroccursfirst.[36FR22902,D