U.S. patent number 3,885,854 [Application Number 05/476,482] was granted by the patent office on 1975-05-27 for loop shaped circuit test point.
This patent grant is currently assigned to GTE Automatic Electric Laboratories Incorporated. Invention is credited to William A. Reimer.
United States Patent |
3,885,854 |
Reimer |
May 27, 1975 |
LOOP SHAPED CIRCUIT TEST POINT
Abstract
A loop-shaped circuit test point formed from resilient wire held
in a rigid mounting block through the combination of torsion and
compression. When the top of the loop is cut, the two ends will
spring apart isolating the circuit connection. When reconnection of
the loop is desired the two top sections are passed by each other
and crossed over and released thus allowing two section of the loop
to hold each other together.
Inventors: |
Reimer; William A. (Wheaton,
IL) |
Assignee: |
GTE Automatic Electric Laboratories
Incorporated (Northlake, IL)
|
Family
ID: |
23892032 |
Appl.
No.: |
05/476,482 |
Filed: |
June 5, 1974 |
Current U.S.
Class: |
439/722;
324/750.3 |
Current CPC
Class: |
H01R
9/00 (20130101); H01R 4/12 (20130101) |
Current International
Class: |
H01R
4/10 (20060101); H01R 4/12 (20060101); H01R
9/00 (20060101); H01r 009/16 () |
Field of
Search: |
;339/218R,218C,218M,17R,17C,19,17L,17LM,147P,149P,217R,214R,222,278R
;29/629,63B ;324/158F,158P,72.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Electronic Products, cem file 2550, p. 76, Mar. 15, 1969..
|
Primary Examiner: McGlynn; Joseph H.
Assistant Examiner: Davie; James W.
Claims
What is claimed is:
1. A loop-shaped circuit test point constructed of electrically
conductive wire comprising: a head shaped portion forming the top
of said test point; a body portion consisting of two legs, the
uppermost portion of said body converging to form a shoulder
portion; a neck portion coupling said shoulder portion to said head
portion, each of said legs following a diverging path from said
shoulder portion, the lower portion of each of said legs passing
through a rigid base on a slightly converging path and passing
through and beyond said base essentially parallel to each other, to
form circuit connecting terminals.
2. A loop-shaped circuit test point as claimed in claim 1 wherein:
said electrically conductive wire is prestressed by mounting in
said rigid base.
3. A loop-shaped circuit test point as claimed in claim 1 wherein:
said electrically conductive wire is of resilient material.
4. A loop-shaped circuit test point as claimed in claim 1 wherein:
said rigid base is constructed of a electrically non-conductive
material.
5. A loop-shaped circuit test point as claimed in claim 1 wherein:
said electrically conductive wire is twisted axially before
insertion into said base.
6. A loop-shaped circuit test point as claimed in claim 1 wherein:
said base further includes at least one additional loop shaped
circuit test point passing therethrough.
7. A loop-shaped circuit test point as claimed in claim 6 wherein:
said base contains at least one electrically non-conductive barrier
located between said test points.
Description
FIELD OF THE INVENTION
This invention relates to circuit testing equipment and more
particularly to a loop-shaped circuit test point for disconnecting
and then reconnecting component(s) in a circuit for troubleshooting
purposes.
DESCRIPTION OF THE PRIOR ART
With the increase in the number of components that can be mounted
on a single printed wiring card it has become necessary to provide
circuit troubleshooting capability during initial circuit design.
This capability is normally provided by bringing test points to
unused connector pins or adding special components that provide
accessible test points. The most difficult circuit configuration to
troubleshoot is one in which a single printed conductor
interconnects a number of similar devices on a printed wiring card.
An error may be traceable to the single printed conductor or one of
the components, but the one way to determine what is creating the
error is to selectively disconnect one or more printed conductors
from the component or vice versa.
In U.S. Pat. No. 2,605,314 to Schelke issued July 29, 1952, holding
means are disclosed whereby an electrical cable containing a
multiplicity of wires is fitted with intermediate disconnect
devices whereby one or more of the wires may be disconnected. In
Schelke each wire is cut and a terminal placed on each end. The
bottom terminal has a nut attached to it such that when a screw is
passed through the top terminal and into the nut the two terminals
would be pulled together. The complete structure is encapsulated
and the terminals coated with an insulating material which holds
the terminals apart. When the circuit is desired to be completed
the screw is tightened down thereby pulling the top terminal
against the bottom terminal. When the circuit is to be opened, the
screw is loosened thereby allowing the top terminal which is held
apart by the insulating material spring up against the screw.
However, Schelke's means are not adaptable for performing the
connect-disconnect function on printed wiring cards, as Schelke
appears only applicable to cable or heavy wire conductors.
In U.S. Pat. No. 3,274,534 to Shortridge issued Sept. 20, 1966, a
circuit connector to make contact with the electronic circuit
module terminals for check-up purposes without damaging the leads
is disclosed. A plurality of biased independently moveable contact
pins is spaced longitudinally across the connector housing and
arranged for movement in extension and retraction. A number of pins
are inclined to one side of the connector housing and others to the
opposite side. Connected to the pins is an output terminal and a
lead from the pins to the terminal. When testing is desired the
apparatus is placed upon the module with the pins fully extended.
Pressure is then applied to the apparatus which forces the pins
back into the housing to insure contact with the module
terminals.
Such a device while apparently working well for electronic circuit
modules, does not have the capability of disconnecting a subcircuit
from a much larger circuit, of the type found on printed wiring
cards, and because of apparent size limitations it would be
inoperable with printed wiring cards. It is the object of this
invention to provide a new and improved circuit test means capable
of use from printed wiring cards.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the loop-shaped circuit test point
in accordance with the present invention.
FIG. 2 is a perspective view of the loop-shaped circuit test point
which has been cut with the two ends displaced from each other in
accordance with the teachings of the present invention.
FIG. 3 is a perspective view of the loop-shaped circuit test point
after the loop has been cut with the wires self-engaging to
complete the circuit in accordance with the present invention.
FIG. 4 is a perspective view of a mounting arrangement containing
several loop-shaped circuit test points mounted on the same solid
base in accordance with the present invention.
In the FIGS. 1-4 comparable portions bear similar second
digits.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to FIG. 1 the loop-shaped circuit test point 10
is placed in a rigid base 11. The solid base 11 is constructed from
an insulated electrically non-conductive material. The test point
10 is formed from a section of resilient electrically conductive
wire. The wire includes a head portion 12 at the top of the loop,
at the bottom of the head the wire converges and finally parallel
to form the neck portion 13. The wire expands then to form the
shoulder portion 14 and following a diverging path the main body 15
angles out slightly from the shoulder 14 until it reaches a rigid
base 11, at which point it passes through the base 11 on a slightly
converging path and emerges at the other side of the base 11
parallel to each other to form the circuit connecting terminals 16
and 17 which are connected to the desired printed wiring conductor
or component.
SUMMARY OF THE INVENTION
The present invention discloses a loop-shaped circuit test point
formed from resilient electrically conductive wire. The test point
is capable of making connection to and/or isolating specific
sections of the printed wiring card and/or specific components
mounted on the printed wiring card. The loop is held in a rigid
non-conductive base through a combination of torsion and
compression whereby the wires pass through the base in an angular
configuration with respect to the main body of the loop and
slightly twisted, such that when the top of the loop is cut, the
wires will spring apart thereby displacing each other so that an
accidental connection will not occur. At this time the desired
tests may be conducted on the circuit by connecting either to one
side of test point or to the individual component. The circuit can
be reconnected simply by forcing the resilient electrically
conductive wires at the two halves of the loop past each other and
crossed over and releasing thereby allowing them to interconnect
because of their curvature.
Several test points may be placed together in close proximity on
the same rigid base, so they would be able to connect several
printed wiring conductors spaced closely together. The size of the
overall test point can be small, thereby enabling it to be
compatible with that of the typical integrated circuit dimensions,
while not interfering with its function and operation. Further, in
cases where high voltages and currents are present, test points may
be constructed of a heavier conductive wire material.
The converging and diverging wire paths result in a compression
force being applied to the top of the loop. When the top of the
loop at the head 12 is cut this compression force causes the wires
to spring apart.
Before the wire is placed in the rigid base 11 each side of the
main body 15 is axially twisted. This results in a force being
applied to the head 12 of the loop, such that when the head 12 is
cut at the crown or center the wires will displace in a plane
perpendicular to their separation resulting from the compression
force described above.
FIG. 3 shows a test point that has been cut and then reconnected.
This is accomplished by physically moving each half of the test
point past each other and crossing over, then releasing, because of
the test point curvature the wires will self-engage and because of
the resiliency of the material the wires will make a solid
electrical contact.
FIG. 4 exemplifies a testing assembly consisting of a multiple
array of test points 41. Test points 41 are held in place by a
solid base 40 similar to the rigid base 11 shown in FIG. 1, with
the exception that the base comes farther up on the test point main
body, and the base 40 contains an isolating regions 48 in which the
test points 41 are situated and a barrier regions 49. By the use of
the barriers 49 accidental short-circuiting of the test points
caused by them coming into contact with each other is avoided.
Further the isolating regions 48 permit proper wire motion to
enable test points to function properly.
While but two embodiments in the present invention are shown, it
will be obvious to those skilled in the art that numerous
modifications can be made, without departing from the spirit of the
present invention, which shall be limited only by the scope of the
claims appended hereto.
* * * * *