Electricity: conductors and insulators – Conduits – cables or conductors – Preformed panel circuit arrangement
Reexamination Certificate
2001-07-10
2003-01-28
Talbott, David L. (Department: 2827)
Electricity: conductors and insulators
Conduits, cables or conductors
Preformed panel circuit arrangement
C174S251000, C174S267000, C174S068200, C174S1170FF, C361S775000, C361S777000
Reexamination Certificate
active
06512187
ABSTRACT:
The present Invention is directed to a circuit board assembly for enclosure in an electrical connection box. The Invention is more particularly directed to an internal circuit assembly in a lattice configuration with vertical or horizontal busbars or wires connected to each other directly and by means of solderless terminals. The Invention will be described with reference to an automobile circuit board, but it is not to be limited thereto.
BACKGROUND OF THE INVENTION
In the past, busbars formed from conductive metal plates have been stamped in the shape of the desired circuit by using a die. Such circuits have been used as the wiring means for, in particular, automotive junction boxes. Alternatively, in place of the busbars, wires have been laid along circuits on an insulative plate, with solderless terminals being fixed to these wires to form solderless connections.
When busbars are used, a vertical busbar is bent from a conductive metal plate into the shape of the desired circuit and is aligned with the circuit on an insulative plate. The wires are preferably solid core and are laid along the circuit on the insulative circuit board and the solderless terminals are fixed to the wires to provide good electrical contact.
However, when circuitry of the foregoing type is provided, a die must be produced based upon each particular circuit desired. As a result, changes in the circuit are both difficult and costly to implement. Moreover, recent trends towards increased numbers of electronic parts has engendered a rapid increase in the number of circuits to be contained within the electrical connection boxes. It is often necessary to have seven or eight horizontal busbars disposed in multiple layers with insulative plates interposed. This leads to larger size and increased costs.
Moreover, the larger number of circuits requires complicated designs for the insulative plates on which the wires or busbars are placed. This makes the production of the insulative plates time-consuming and, in addition, requires substantial investments for the equipment necessary. When vertical busbars are used, they are formed integrally with tabs for connections to external circuits.
Thus, the busbars must be stamped with dies and, after this step is complete, must then be bent into the shape of the circuits. This increases the number of processing steps and further adds to the expense and difficulty in making any changes.
In an attempt to solve these problems, a number of structures have been proposed. Japanese OPI 60-35911 suggests the electrical connection box as shown in FIGS.
12
(A),
12
(B),
12
(C), and
12
(D). Unit case
1
is formed of lattice-shaped insulative material. Lateral conductive wires
3
and longitudinal conductive wires
4
have upside-down U-shaped cross-sections. At appropriate intersections, L-shaped solderless terminals
2
and tabbed solderless terminals
5
are engaged and connected to lateral conductive wires
3
and longitudinal conductive wires
4
to form the desired circuitry.
With the foregoing structure, circuits are formed by using solderless terminals
2
and
5
to connect the lateral and longitudinal conductive wires
3
and
4
. Thus, circuit changes can be easily implemented simply by changing the positions of the solderless terminals. However, the lateral and longitudinal conductive wires are formed with the unique U-shaped cross sections which do not permit the use of standard solid core wires and also add to the cost. Moreover, wires
3
and
4
tend to deform when a load is applied, so that the opening of the U-shape is narrowed. Once this takes place, the connection between solderless terminals
2
and
5
and lateral and longitudinal conductive wires
3
and
4
becomes loose, whereby reliable electrical contact is not maintained.
Another attempt at solving the foregoing problems is to be found in Japanese OPI 56-130989. As shown in FIG.
23
(A) and
23
(B), circuit board
30
, intended to be enclosed in an electrical connection box (not shown), is provided with stamped sections
33
which are stamped out of a conductive metal plate to form conductive lattice
34
. Insulative sheets
32
are laminated on either side of the conductive lattice. To connect circuit board
30
with external circuits, wires are connected to the perimeter of conductive lattice
34
.
In this structure, the circuits are formed by cutting out unneeded sections
37
. Changes in such circuits can be implemented without undue difficulty, but there is no improvement in yield for the conductive metal plate, since the circuit is formed by stamping and there are many stamped sections
33
. Wires can only be connected to the perimeter of conductive lattice
34
; thus, the external circuits cannot be directly electrically linked to inner portions thereof. As a result, the connections are both complex and inefficient.
A further attempt to solve the foregoing problems is to be found in Japanese OPI 60-35912 as shown in FIGS.
34
(A),
34
(B), and
34
(C). The insulative plate is in the form of unit case
1
which comprises lateral and longitudinal frames
61
and
62
which intersect each other at approximately right angles. Similarly, lateral and longitudinal conductors
63
and
64
also intersect on unit case
1
. L-shaped solderless terminals
65
and
67
are inserted into the lateral and longitudinal conductors at prescribed intersections to form the desired circuit. External wire
66
is connected to this circuit through a solderless connection between conductor
63
and solderless connection blade
68
at the tip of solderless terminal
67
connected to the end of external wire
66
.
This structure permits sharing of the insulative plate, but the plate must be assembled as a lateral/longitudinal frame and the wire guide cavities must be disposed throughout the frame. As a result, the structure becomes large and complex, increasing its cost and requiring a larger electrical connection box to enclose it. Also, in order to make the desired connections to the external circuit, solderless terminal
67
, connected to external wire
66
, is directly connected to the conductor. Thus, the external wire cannot be connected once the electrical connection box has been assembled.
It is the object of the present Invention to overcome the foregoing defects of the prior art. More specifically, it is intended to provide a solderless connection device for an internal circuit in an electrical connection box, while allowing the circuit to be formed easily and altered without major expense.
SUMMARY OF THE INVENTION
A circuit board assembly is provided which is particularly adapted for—although not limited to—enclosure in an electrical connection box for automotive use. There is a first plurality of lateral busbars substantially parallel to each other, as well as a second plurality of longitudinal busbars, also substantially parallel to each other. The two pluralities intersect each other, preferably at substantially right angles. A third plurality of slits is provided on the lateral busbars, and a fourth plurality of slits is on the longitudinal busbars. Each set of slits engages the other, at at least some points at which the lateral and longitudinal busbars intersect. Any portions of the busbars which are unnecessary to the circuits desired are cut away, thereby forming the conductive member. This member rests on one surface of a planar insulative plate. There is a fifth plurality of solderless terminals in electrical contact with predetermined positions on the conductive member.
It has been found preferable to have a pair of slits, one on each of the lateral and longitudinal busbars, at each of the intersections. It is further desirable to provide lattice grooves in the insulative plate so that at least a portion of the conductive member can be embedded therein. The insulative plate is. also desirably provided with one or more insertion grooves, each adapted to receive one of the solderless terminals. There is also at least one cutting groove into which a cutting tool may be inserted in order to cut awa
Aoki Kazuhiro
Sato Masanobu
Sumida Tatsuya
Bierman, Muserlian and Lucas
Patel I B
Sumitomo Wiring Systems Ltd.
Talbott David L.
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