Singer Gear #445491-S
Top vertical shaft gear
Fits: 242, 247, 248, 252, 257, 259, 267, 300, 362, 368, 1263 and some 6100 series, 7100 series (some of these series did not use this gear they use timing belt #423107-001). This gear has a set screw, not for models which use a pin (pin type gear no longer available).
Mates with upper horizontal gear #319695