Electrical circuit tester

An electrical circuit tester for use in testing terminal blocks having protruding electrical connectors, the tester comprising a body made from an insulating material, the body having a plurality of circuit testing assemblies, each assembly including a chamber, each chamber including a chamber extension extending to the exterior of the body and capable of receiving the electrical connectors. Positioned within each chamber is a piston having a piston rod extending therefrom, the piston rod extending into the chamber extension. The chamber includes a piston retaining wall having an aperture through which the piston rod moves. When the piston rod is in its fully extended state, there is room in the chamber extension to receive the electrical connector. Positioned within the chamber is a conductive grommet and a resilient conductive spring which contacts the grommet and functions to urge the piston and piston rod to the fully extended position. Conductors extend from the grommets to the exterior of the tester, and may eventually be connected to an electronic apparatus for testing the circuits in the telephone terminal blocks.

What is claimed is:

1. Apparatus for simultaneously establishing electrical contact with a plurality of linearly arranged conductive terminals of uneven height which protrude from a substrate, said apparatus enabling the testing of circuitry connected to said terminals, the apparatus comprising:

elongated bar means, said bar means being comprised of a non-conductive material, said bar means defining a linear array of chambers, said chambers each having an axis and the axes of said chambers being substantially parallel, said bar means further defining extensions of said chambers having a variable cross-sectional area, the first larger cross-sectional area ends of said chamber extensions lying in the plane of a first exterior surface of said bar means whereby terminals protruding from a substrate may be guided by a wall of said chamber extensions toward the chamber axis, first ends of the said chambers and the second ends of said chamber extension being in communication via apertures having a smaller cross-sectional area than the adjacent chamber whereby a shoulder is defined at the said first ends of said chambers;

electrically conductive piston means disposed for axial movement in each of said chambers, said piston means being dimensioned such that movement thereof in a first direction will be limited by said shoulders, said piston means being of shorter axial length than each of said chambers;

electrically conductive piston rod means, said piston rod means comprising conductive extensions of said piston means, said piston rod means extending into said chamber extensions via said apertures for contacting a terminal, said piston rod means being of smaller diameter than said piston means;

electrically conductive spring means positioned in said chambers to resiliently bias said piston means toward the first ends of said chambers, said spring means allowing said piston means to retract when said piston rod means contact a terminal, said spring means defining conductive paths from said piston rod means to the second ends of said chambers;

means cooperating with said bar means to define an elongated cavity, at least a portion of a second exterior surface of said bar means disposed oppositely to first exterior surface being located within said cavity; and

means extending into the second ends of said chambers for electrically connecting said spring means to individual conductors of a multi-conductor cable of a test instrument, said cable being partly positioned in said cavity.

2. The apparatus of claim 1 wherein said chamber extensions have a generally rectangular cross-sectional shape and wherein the variable cross-sectional area of said chamber extensions is defined by tapering walls which separate adjacent chamber extensions of the array.

3. The apparatus of claim 2 wherein said piston rod means have a shorter axial length than said chamber extensions.

4. The apparatus of claim 3 wherein said connecting means further comprises:

an array of apertures extending between said bar means chambers and said bar means second exterior surface; and

means establishing an electrical connection to said spring means via said apertures.