Abstract: Methods and apparatus for controlling a fluid passage provide at least one sliding gate movable transversely to that fluid passage. The fluid passage or the gate is maintained open in a first position of the gate, and is closed in a second position of that gate. A detent detains the gate in one of its first and second positions against a bias acting continuously on that gate. Upon release from that detent, the gate slides by virtue of its bias to the other of its first and second positions. The gate and fluid passage may be incorporated in a frangible connection and the gate may be released from its detent for automatic closure by its bias upon breakage of that frangible connection. Alternatively, the gate may be provided with a slanted surface which abuts another slanted surface around the fluid passage in the first position of the gate.

Abstract: Methods and apparatus for controlling a fluid passage provide at least one sliding gate movable transversely to that fluid passage. The fluid passage or the gate is maintained open in a first position of the gate, and is closed in a second position of that gate. A detent detains the gate in one of its first and second positions against a bias acting continuously on that gate. Upon release from that detent, the gate slides by virtue of its bias to the other of its first and second positions. The gate and fluid passage may be incorporated in a frangible connection and the gate may be released from its detent for automatic closure by its bias upon breakage of that frangible connection. Alternatively, the gate may be provided with a slanted surface which abuts another slanted surface around the fluid passage in the first position of the gate.

Abstract: An analogue to digital converter using several flash converter units to convert successively the increasingly lower orders of resolution, wherein the transition from a stage of lower magnitude of resolution to that stage of successively higher magnitude of resolution is obtained by physically isolating the resistor element of the resistor ladder of the first flash converter wherein the unresolved portion of the input voltage falls, and substituting a second flash converter comprising a resistor ladder of same total resistance as the resistor element it replaces but of higher resolution by one order of magnitude; then repeating the same with each successive flash converter.

Abstract: A chip substrate providing registration features for chip components on the opposite to the circuit side with interconnecting through holes and method and means for simultanuously trimming these registration features for dimentional and location accuracy, drilling the interconnecting through holes for perfect registration with the registration features, and photoetching the high density portion of the circuit in and around the chip area.