single-pole three throw switch 单极三投开关

three-throw switch 三投开关 ; 三向转辙器

pole three throw switch 单极三投开关

single pole three throw switch 单刀三投开关

three-pole double-throw switch 三刀双掷开关 ; 三刀双投开关

three-pole single-throw switch 三刀单掷开关 ; 三刀单投开关

three-pole double-throw knife switch 三极双掷闸刀开关

switch three-throw 三向开关 ; 三向道岔

three pole double-throw switch 三刀双投开关