Abstract: There is disclosed a fastener useful for the precise positioning of a plurality of plates in a parallel, spaced-apart array. The fastener has a cylindrical standard with distal fixed abutments and carries a plurality of spacers that are axially adjustable on the standard. At least one spacer is axially extendable, and has a user-adjustable cam to control its axial length, thereby accommodating for variable thicknesses of the intermediate plates. The fastener is disclosed as particularly useful for the precise orientation of the parallel plates of a fixture used in equipment for automated testing of printed circuit boards.

Abstract: There is disclosed an apparatus for the automated loading of probes in a probe head intended for use in automated testing of printed circuit boards. The invention automatically places probes in a probe head at on-grid and at off-grid test points, with probes for the latter test points being vertically inclined from base ends which are on-grid to test ends which are off-grid, corresponding to the off-grid test points of the printed circuit board. In the method, the probes are stored in a dispensing unit which is fully populated with on grid probes at a uniform grid spacing. A mask is custom drilled for the circuit under test at on-grid locations and is used to permit transfer of selected probes from the dispensing unit to a probe cassette. The probe cassette is then transferred to a probe loading unit which is loaded with a stack of the probe plates intended for the probe head.

Abstract: There is disclosed a printed circuit board test apparatus which has a test bed formed by a planar member having a plurality of through channels at close spacing across its surface to receive test probes. Each of the test probes comprises a tubular body having a top contact surface and a socket at its opposite end. A plurality of planar switch cards are provided with each card supporting, along one edge thereof, a plurality of pins which are disposed in rows at locations corresponding to the predetermined locations of the through channels of the test board. Each switch card has a plurality of electrical circuits which interconnect with selected pins and which are connected to selected contacts of a connector located at another extremity of the switch card.

Abstract: There is disclosed a method, and apparatus useful in the method, for the automated loading of probes in a probe head intended for use in automated testing of printed circuit boards. The invention automatically places probes in a probe head at on-grid and at off-grid test points, with probes for the latter test points being vertically inclined from base ends which are on-grid to test ends which are off-grid, corresponding to the off-grid test points of the printed circuit board. In the method, the probes are stored in a dispensing unit which is fully populated with on grid probes at a uniform grid spacing. A mask is custom drilled for the circuit under test at on-grid locations and is used to permit transfer of selected probes from the dispensing unit to a probe cassette. The probe cassette is then transferred to a probe loading unit which is loaded with a stack of the probe plates intended for the probe head.