A
railroad switch machine gear box having a low vertical profile is provided, wherein a compound gear rotatably mounted within a housing along a first
vertical axis cooperatively engages an adjacent main
crank gear. The main
crank gear is rotatably mounted within the housing about a main
crank shaft that extends vertically within the gear box housing along a second
vertical axis that is different than the first
vertical axis. A
bevel gear fixedly mounted to a hand throw shaft rotatably mounted within the housing along a first
horizontal axis cooperatively engages the compound gear, thereby to rotate the compound gear when the hand throw shaft is rotated, typically with a hand throw lever affixed to the hand throw shaft external to the housing. The hand throw shaft may be rotatable about an eccentric shaft that is independently mounted and rotatable with the housing along the first
horizontal axis. A motor / manual mode selector lever may be affixed to the eccentric shaft external to the gear box housing, thereby to rotate the eccentric shaft in a manner known in the art. Typically, rotation of the mode selector lever in a first direction selects a manual mode of gear box operation; rotation in the opposite direction selects a
power mode of operation. A
clutch yoke may be slidably mounted about a
clutch cup
assembly and the main crank shaft, and may be pivotable at a first end along a pivot pin positioned along a pivot axis that is parallel to the first
horizontal axis, thereby to provide the
advantage of simplifying movement of the hand throw lever and the mode selector lever from one side of the gear box to the other. The pivoting action of the eccentric shaft may be detected by a
proximity sensor that senses a target associated with the second end of the
clutch yoke.