Abstract: Transmission for tractors comprising an input shaft rotatably supported by a casing having means defining openings therein, a second speed change shaft disposed coaxially with the input shaft and rotatably supported at its opposite ends by further means defining openings in the casing, and speed change gears positioned outside the casing to operatively connect the input shaft and a first speed change shaft.

Abstract: Axle case comprising a tube, a substantially semispherical first member integral with the tube and a substantially semispherical second member connected to the first member and rotatable relative thereto.

Abstract: Rotary valve comprising a rotatable stem having a valve disk fixed thereto and disposed within a valve case, a slidable tube and a rotatable tubular member each positioned coaxially with the stem and connected to the valve case, first screw-thread means for holding the stem and the slidable tube in screw-thread engagement with each other, and second screw-thread means for holding the slidable tube and the tubular member in screw-thread engagement with each other, the first screw-thread means having a larger lead angle than the second screw-thread means, so that the rotation of the tubular member rotates the stem of the valve disk.