▁break ers ▁are ▁used . ▁These ▁devices ▁use ▁a ▁snap ▁action ▁mechanism ▁which ▁opens ▁the ▁switch ▁contacts ▁rapidly , ▁and ▁feature ▁an ▁arc ▁ch ute ▁where ▁the ▁arc ▁caused ▁by ▁opening ▁the ▁switch ▁is ▁qu en ched . ▁These ▁devices ▁also ▁prevent ▁injury ▁due ▁to ▁accident al ▁contact , ▁as ▁all ▁of ▁the ▁current ▁carrying ▁metal ▁parts ▁of ▁the ▁switch ▁are ▁hidden ▁within ▁or ▁surrounded ▁by ▁ins ulating ▁gu ards . ▁ ▁References ▁▁▁▁▁▁▁▁▁ ▁Category : Switch es ▁ ▁de : Mess ersch alter <0x0A> </s> ▁In ves co ▁Ltd . ▁is ▁an ▁American ▁independent ▁invest ment ▁management ▁company ▁that ▁is ▁head qu arter ed ▁in ▁Atlanta , ▁Georgia , ▁United ▁States , ▁and ▁has ▁branch ▁offices ▁in ▁ 2 0 ▁countries . ▁Its ▁common ▁stock ▁is ▁a ▁constitu ent ▁of ▁the ▁S & P ▁ 5 0 0 ▁and ▁tr ades ▁on ▁the ▁New ▁York ▁stock ▁exchange . ▁In ves co ▁oper ates ▁under ▁the ▁In ves co , ▁Tr im ark , ▁In ves co ▁Per pet ual , ▁W L ▁Ross ▁& ▁Co ▁and ▁Pow ers h ares ▁brand ▁names . ▁ ▁History ▁ ▁In ves co ▁( then ▁officially ▁sp elled ▁with ▁all - cap ital ▁letters : ▁IN V ES CO ) ▁was ▁created ▁in ▁Atlanta ▁in ▁ 1 9 7 8 ▁when ▁Cit iz ens ▁& ▁Southern ▁National ▁Bank ▁div ested ▁its ▁money ▁management ▁operations . ▁In ▁ 1 9 8 8 , ▁the ▁company ▁was ▁purchased ▁by ▁the ▁British ▁firm ▁Britann ia ▁Ar row , ▁based