Astime passedby,itwasfoundthatwiperoperatingataconstantspeedwere ineffective
againsthigh-speedrainsorsnowfallsleavingthepurposeofhavingawiperunfulfilled.Thusthe
wipersinthecarmodelsthatweremanufacturedafterthelate1960shadadjustablespeeds.
Alongwithhavingconstanthighspeeds,themoderncarmodelsalsocomewithanintermittent
setting.Theintermittentlocationmeansthatatimeintervalseparateseverycycleofthemotion
ofwipers.Itwasnecessaryaswhentherainfallsatlowspeedsconstantspeedofwiperscan
exertanexcessiveloadonthebatteries,thustopreventthissituation,theintermittentsetting
came into the picture.
Nowadayswecanfindwipersinstalledinnearlyalltheautomobilesthatweseeeveryday
rangingfromacarto atrain,bikes,buses,aircraft,trucksandwhatnot.Allthesemodesof
transportationhavedifferentgeometriesofwindscreenwipersandalsoadifferentnumberof
armsdependinguponthewindscreensizethatthewiperhastocover.Also,pantographarms
areusednowadays,whichcanbeunderstoodasamechanicallinkagebetweentwosmallarms