In a preferred embodiment, a fluid flow valve, including: an elongate body having an axially extending cavity defined therethrough and having fluid inlet and outlet ports; a hollow seat assembly disposed in the body for the passage therethrough of a fluid; a shaped first aperture defined through a wall portion of the seat assembly; and a plug selectively axially moveable in the hollow seat assembly and along the shaped first aperture such that the fluid flows into the hollow seat assembly, upwards past the plug into the first aperture, through the first aperture, downwards past the plug, and out of the hollow seat assembly, the position of the plug along the aperture determining rate of flow of the fluid through the valve.

A feature of this invention is a spool valve which has a spool with an O-ring seal, said seal having a given longitudinal dimension, the spool operating in a bore in a housing to open and close a port opening into said bore, said port formed of a plurality of apertures, each aperture having a diameter, parallel to the longitudinal axis of said O-ring, which is smaller than said given longitudinal dimension of said seal.

A reciprocating sliding gate valve with tubular housing and one movable and one stationary gate having multiple fluid conducting ports, which overlap with solid wall partitions spaced between said ports when the valve is closed following sliding, reciprocating displacement of the movable gate, and wherein the interface between the stationary gate and the tubular body bore is sealed by the usual pipe line flange gasket; both gates and other internal parts being readily removable through one end of the tubular housing bore for ease of assembly.

A sequencing manifold for selectively drawing air from a plurality of vacuum channels, comprises, a fixed element having an outer surface and an internal cylinder, the fixed element further including a plurality of holes passing from the outer surface to the internal cylinder, the plurality of holes communicating with the plurality of vacuum channels. A piston is movably disposed within the internal cylinder and includes a hollow portion in communication with a device for drawing air. The piston is movable within the internal cylinder to align the hollow portion with a predetermined number of the plurality of holes for selectively drawing air from the predetermined number of the plurality of holes.

Hydraulic controls in a transmission for engaging a clutch for the F-R, or forward or reverse, direction before a clutch for first, second, or third speed. Flow of hydraulic fluid to each direction clutch and to each speed clutch is by way of a reducing valve which modulates fluid pressure in controlled way by throttling the flow. After the power unit for the clutch for the F-R clutches and the power unit for the clutch for first, second or third speed are filled with fluid by the reducing valve, pressure in the power units is then slowly raised by the valve linearly toward is maximum; for this purpose the hydraulic controls are supplied by a single source of hydraulic fluid and operate therefrom to provide a pair of modulated pressure outputs which are maintained with varying differences throughout their range of operation, and which operate the selected one of the F-R clutches and the selected one of the first second or third clutches. The F-R clutches are the ones which receive the higher modulated pressure output and which are constructed, proportioned in size, and arranged to have a higher speed capability and smaller energy absorbing capacity in their design, and they operate so as to be fully hydraulically engaged at the higher pressure output, and hence slightly before, the speed clutches.