Abstract: A socket is molded at the edge of a plastic resin tube with a male mold and a female mold wherein the male mold comprises a large diameter part, a tapered part and a small diameter part and the female mold comprises a barrel for surrounding the male mold small diameter part with a gap larger than the thickness of the resin tube and a split stopper for closing the opening of the annular space formed between the male mold small diameter part and barrel.

Abstract: A gear transmission for an electrical operation means is disclosed wherein a reduction gear mechanism is provided to reduce valve opening and closing speed. The gear box has a cylindrical shape in which upper and lower plates support two gear shafts which rotatably support a plurality of pairs of large and small gears. The large gear is integrally and coaxially secured to the small gear in each pair. A small gear of a first pair of gears supported by one of the gear shafts is engaged with a large gear of a second pair of gears supported by the other gear shaft. The small gear of the second pair is in turn engaged with a large gear of a third pair of gears supported by the one of the gear shafts. The third pair of gears is rotated about the one of the gear shafts independent of the rotation of the first pair of gears.