Programmable probe fixture and method of connecting units under test with test equipment

Claim 2

A connecting device for transmitting signals between a unit under test and an electrical interface comprising cylinder means, piston means reciprocably mounted within the cylinder closing one end of the cylinder, means closing the other end of the cylinder, the cylinder means, piston means and closing means defining an expandable chamber, means for sealing the chamber, means for introducing a fluid at a predetermined pressure into the chamber, the piston means being movable in one direction to a first position in response to a first predetermined pressure in the chamber and in the other direction to a second position in response to a second predetermined pressure in the chamber, means for limiting the axial movement of the piston means, first conductive means mounted on the piston means and movable therewith into contact with the unit under test when the piston is in the second position and out of contact with the unit under test when the piston is in the first position, second conductive means electrically coupled to the first conductive means forming therewith a continuous conductive path providing a conduit for the passage of electrical signals, the second conductive means adaptable for connection with the electrical interface, and a first stem portion of reduced diameter depending from the piston means into the expandable chamber slidably received by the closing means for guided movement in the expandable chamber whereby signals are transmittable between the unit under test and the electrical interface when the piston is in the second position.

Claim 3

A connecting device for transmitting signals between a unit under test and an electrical interface comprising cylinder means, piston means reciprocably mounted within the cylinder closing one end of the cylinder, means closing the other end of the cylinder, the cylinder means, piston means and closing means defining an expandable chamber, means for sealing the chamber, means for introducing a fluid at a predetermined pressure into the chamber, the piston means being movable in one direction to a first position in response to a first predetermined pressure in the chamber and in the other direction to a second position in response to a second predetermined pressure in the chamber, means for limiting the axial movement of the piston means, first conductive means mounted on the piston means and movable therewith into contact with the unit under test when the piston is in the second position and out of contact with the unit under test when the piston is in the first position, second conductive means electrically coupled to the first conductive means forming therewith a continuous conductive path providing a conduit for the passage of electrical signals, the second conductive means adaptable for connecting with the electrical interface whereby signals are transmittable between the unit under test and the electrical interface when the piston is in the second position, wherein, the piston means has first and second stem portions of reduced diameter affixed thereto and extending axially therefrom, guide means in the cylinder slidably receiving the stem portions for guiding the movement of the piston, wherein the guide means includes a bushing mounted in the cylinder means above the piston means having a central bore therethrough slidably receiving one of the stem portions of the piston means and an aperture of reduced diameter portion below the piston means slidably receiving the other of the stem portions of the piston means, means securing the bushing within the cylinder means, and the conductive means extending beyond the cylinder means when the piston is in the second position for contacting the unit under test and being substantially retracted within the cylinder and securing means when the piston is in the first position.

Claim 4

A connecting device for transmitting signals between a unit under test and an electrical interface comprising cylinder means, piston means reciprocably mounted within the cylinder closing one end of the cylinder, means closing the other end of the cylinder, the cylinder means, piston means and closing means defining an expandable chamber, means for sealing the chamber, means for introducing a fluid at a predetermined pressure into the chamber, the piston means being movable in one direction to a first position in response to a first predetermined pressure in the chamber and in the other direction to a second position in response to a second predetermined pressure in the chamber, means for limiting the axial movement of the piston means, first conductive means mounted on the piston means and movable therewith into contact with the unit under test when the piston is in the second position and out of contact with the unit under test when the piston is in the first position, second conductive means electrically coupled to the first conductive means forming therewith a continuous conductive path providing a conduit for the passage of electrical signals, the second conductive means adaptable for connecting with the electrical interface whereby signals are transmittable between the unit under test and the electrical interface when the piston is in the second position, wherein, the piston means has first and second stem portions of reduced diameter affixed thereto and extending axially therefrom, guide means in the cylinder slidably receiving the stem portions for guiding the movement of the piston, wherein the guide means includes a bushing mounted in the cylinder means above the piston means having a central bore therethrough slidably receiving one of the stem portions of the piston means and an aperture of reduced diameter portion below the piston means slidably receiving the other of the stem portions of the piston means, means securing the bushing within the cylinder means, and the conductive means extending beyond the cylinder means when the piston is in the second position for contacting the unit under test and being substantially retracted within the cylinder and securing means when the piston is in the first position.

Claim 5

The connecting device as claimed in claim 2 further comprising biasing means for biasing the piston means from the second to the first position.

Claim 6

The connecting device as claimed in claim 3 wherein the biasing means is a spring mounted concentrically over the first stem portion between the piston means and the bushing for biasing the piston means from the second position to the first position.

Claim 7

The connecting device as claimed in claim 2 further comprising a shoulder formed in the guide means and wherein the limiting means includes the bushing when the piston is in the second position and the shoulder means when the piston is in the first position.

Claim 8

The connecting device as claimed in claim 2 wherein the means closing the other end of the chamber includes a first closure fitting concentrically mounted over one of the stem portions of the piston means and the second conductive means, and the means for sealing the chamber includes a first sealing means mounted on the piston.

Claim 9

The connecting device as claimed in claim 6 wherein, the means closing the other end of the chamber includes a second closure fitting mounted in connection with the cylinder means having a central bore therethrough, a passage in the cylinder means connecting the central bore of the second closure fitting to the chamber for the ingress and egress of the fluid under pressure, and the means sealing the chamber includes a second sealing means mounted between the first closure fitting and the guide means.

Claim 10

The connecting device as claimed in claim 1 wherein the first stem portion has a portion of widened diameter at its lower end spaced from the piston means, said widened diameter portion of said first stem portion guidingly contacting said closing means in said expandable chamber.

Claim 11

The connecting device as claimed in claim 1 wherein said means closing the other end of the expandable chamber means comprises an aperture which provides a passage for the fluid under pressure into the chamber.

Claim 12

The connecting device as claimed in claim 8 wherein the closing means and the first stem portion are electrically conductive members in sliding electrical contact, and the cylinder means is made of non-conductive material and guidingly contacts said piston means.

Claim 13

The connecting device as claimed in claim 1 wherein the piston means is made of an electrically conductive material, the first conductive means includes an elongated second stem of conductive material affixed to the piston, the closing means is a conductive closure fitting having a central bore therethrough forming part of said expandable chamber, the first stem of the piston means being received within the central bore of the closure fitting and in sliding electrical contact therewith, and the closure fitting and first stem forming portions of the conductive means.

Claim 14

The connecting device as claimed in claim 11 wherein the first stem has a plurality of depending elastic fingers biased outwardly into contact with the closure fitting.

Claim 15

The connecting device as claimed in claim 11 wherein the first stem is a stamped metal member having a plurality of depending flange portions connected to the piston means and biased outwardly into contact with the closure fitting bore.

Claim 16

A connecting device as claimed in claim 1 wherein the first conductive means includes the piston means and an elongated second stem portion of conductive material connected to the piston means and extending therefrom in a direction opposite to said first stem portion, and guide means having a central bore therethrough for guidingly receiving said second stem portion.

Claim 17

The connecting device as claimed in claim 1 further comprising means for limiting the axial movement of the piston in the first and second positions and said limiting means in the first position including the closure fitting.

Claim 18

A fixture for programmable probes for transmitting signals between a unit under test and an electrical interface having support means, each probe of a number of probes being mounted on the support means for independent guided movement of individual probes between a first position and a second position, a fluid-pressure-operated expandable chamber for guiding and moving the probes between the first and second position, conductive means forming a continuous conductive path between the unit under test and the electrical interface for probes in the second position, the support means having guide means forming side wall portions of the expandable chamber means, and each probe having a piston slidingly received within the guide means and forming one end wall portion of the expandable chamber, wherein the improvement comprises, the probe having a first stem of reduced diameter depending from the piston into the expandable chamber and guidingly received by a portion of the support means, further comprising means closing the other end of the expandable chamber means, and the first stem of reduced diameter being slidingly received by the closing means while said closing means provides a passage for the fluid under pressure, wherein a second elongated stem is connected to the piston means, the first and second stems and piston means have a central bore therethrough, and the conductive means includes two separate circuits electrically isolated from each other and mounted within the central bore of the stem portions and piston means.

Claim 19

A fixture for programmable probes for transmitting signals between a unit under test and an electrical interface having support means, each probe of a number of probes being mounted on the support means for independent guided movement of individual probes between a first position and a second position, a fluid-pressure-operated expandable chamber for guiding and moving the probes between the first and second position, conductive means forming a continuous conductive path between the unit under test and the electrical interface for probes in the second position, the support means having guide means forming side wall portions of the expandable chamber means, and each probe having a piston slidingly received within the guide means and forming one end wall portion of the expandable chamber, wherein the improvement comprises, the probe having a first stem of reduced diameter depending from the piston into the expandable chamber and guidingly received by a portion of the support means, further comprising means closing the other end of the expandable chamber means, and the first stem of reduced diameter being slidingly received by the closing means while said closing means provides a passage for the fluid under pressure, wherein a second elongated stem is connected to the piston means, the first and second stems and piston means have a central bore therethrough, and the conductive means includes two separate circuits electrically isolated from each other and mounted within the central bore of the stem portions and piston means.

Claim 20

The connecting device as claimed in claim 14 wherein the means closing the other end of the chamber includes a first closure fitting concentrically mounted over the first stem, and the means for sealing the chamber includes a first sealing means mounted on the piston.

Claim 21

The fixture as claimed in claim 16, wherein the first and second stem portions include an outer hollow cylindrical housing affixed to the piston and reciprocable, the conductive means including an electronic circuit borad on a substrate, said board being mounted within the outer hollow cylinder, and shock absorbing means for the probes.

Claim 22

The fixture as claimed in claim 18, wherein the shock absorbing means comprises the outer hollow cylinder having a recessed end, an inner cylindrical housing having a central bore therethrough in which the conductive means is mounted, the conductive means having a portion extending beyond the outer cylinder for contacting the unit under test, the inner housing received within the recessed end of the outer cylinder and movable relative thereto, means for limiting the movement of the inner housing relative to the outer cylinder and for securing the cylinder and housing together, and spring means for biasing the inner housing outwardly relative to the outer cylinder whereby impact of the conductive means against the unit under test when the piston is moved to the second position causes a slight inward movement of the inner housing relative to the outer cylinder against the action of the biasing means.

Claim 23

The fixture as claimed in claim 16, wherein the piston means, first and second stem portions are made of a non-conductive material.

Claim 24

The fixture as claimed in claim 16 comprising one of the circuit means including a conductive tip, and a central connector coupled thereto mounted to the outer end of the second elongated stem and movable therewith into contact with the unit under test when the piston is in the second position, and the other of the circuit means including a shielding circuit around the conductive tip and the central conductor.

Claim 25

The fixture as claimed in claim 21, wherein the two circuit means includes a shielded cable assembly comprising a central conductor affixed to the conductive tip, a conductive shielding means surrounding the conductive tip and central conductor, and insulative means substantially surrounding the tip and the conductor and supporting the same within the shielding means in electrical isolation therefrom, means for securing the assembly within the central bore of the piston and first and second stem portions, a portion of the tip extending beyond the conductive shielding means and the insulative means.

Claim 26

The connecting device as claimed in claim 21, further comprising the conductive means of one probe including a second probe, and means connecting the second probe to the shielding circuit means of the one probe for reciprocation therewith and adapted for contacting the unit under test, and means for guiding the second probe, the characteristic impedance between the first and second probes having a predetermined value.

Claim 27

The connecting device as claimed in claim 23, wherein the guide means for the second probe includes the support means having an opening, a post secured to the conductive connecting means and received in the opening for slidable guided movement therein.

Claim 28

A fixture for programmable probes for transmitting signals between a unit under test and an electrical interface having support means, each probe of a number of probes being mounted on the support means for independent guided movement of individual probes between a first position and a second position, a fluid-pressure-operated expandable chamber for guiding and moving the probes between the first and second position, conductive means forming a continuous conductive path between the unit under test and the electrical interface for probes in the second position, the support means having guide means forming side wall portions of the expandable chamber means, and each probe having a piston slidingly received within the guide means and forming one end wall portion of the expandable chamber wherein the improvement comprises the conductive means including two separate circuits electrically isolated from each other and mounted on the piston means.

Claim 29

A fixture for programmable probes for transmitting signals between a unit under test and an electrical interface having support means, each probe of a number of probes being mounted on the support means for independent guided movement of individual probes between a first position and a second position, a fluid-pressure-operated expandable chamber for guiding and moving the probes between the first and second position, conductive means forming a continuous conductive path between the unit under test and the electrical interface for probes in the second position, the support means having guide means forming side wall portions of the expandable chamber means, and each probe having a piston slidingly received within the guide means and forming one end wall portion of the expandable chamber wherein the improvement comprises the conductive means including two separate circuits electrically isolated from each other and mounted on the piston means.

Claim 30

The fixture as claimed in claim 25, wherein a second elongated stem is connected to the piston means, the first and second stems and piston means have a central bore therethrough, and the two separate circuits of the conductive means are mounted within the central bore of the stem portions and piston means.

Claim 31

The connecting device as claimed in claim 25, further comprising the conductive means of one probe including a second probe, and means connecting the second probe to one of the circuit means of the one probe for reciprocation therewith and adapted for contacting the unit under test, and the characteristic impedance between the first and second probes having a predetermined value.

Claim 32

The connecting device as claimed in claim 27, further comprising means for guiding the second probe.

Claim 35

The method as claimed in claim 29, wherein the step of guidingly receiving the reduced diameter portion comprises closing the other end of the expandable chamber with means including a conductive member having a central bore while providing a passage for the fluid under pressure, slidingly contacting the reduced diameter portion within the central bore of the conductive closure member, and coupling the signals through the probe, the piston stem and the conductive closure member to the electrical interface.

Claim 36

The method as claimed in claim 30, wherein the supporting step includes supporting the probe within a non-conductive chamber.

Claim 37

The method as claimed in claim 30, comprising applying the fluid pressure to operate the piston through the central bore of the conductive closure member.

Claim 40

The method as claimed in claim 33, comprising the steps of contacting one of the circuit means against the unit under test and coupling signals of one potential therethrough while coupling signals of a different potential through the other circuit means.

Claim 41

The method as claimed in claim 33, comprising the step of one circuit means being shielding means for the other circuit means and conducting stray signals through the shielding means.

Claim 42

The method as claimed in claim 33, comprising the step of resiliently supporting the two circuit means within the hollow piston for absorbing the impact shock of contacting the one circuit means against the unit under test.

Claim 43

The method as claimed in claim 33, comprising the steps of grounding the unit under test by contacting a conductive member coupled to the shielded circuit means against a second terminal of the unit under test.

Claim 44

The method as claimed in claim 37, further characterized by the step of: guiding the conductive member during the extension step.

Claim 47

The method as claimed in claim 39, comprising the steps of grounding the unit under test by contacting a conductive member coupled to one of the circuit means against a second terminal of the unit under test.

Claim 48

The method as claimed in claim 40, further characterized by the step of guiding the conductive member during the extension step.