Information
-
Patent Grant
-
6224430
-
Patent Number
6,224,430
-
Date Filed
Tuesday, November 30, 199924 years ago
-
Date Issued
Tuesday, May 1, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Sircus; Brian
- Le; Than-Tam
Agents
-
CPC
-
US Classifications
Field of Search
US
- 439 68
- 439 78
- 439 709
- 439 712
- 439 801
- 439 814
- 439 7331
- 439 947
-
International Classifications
-
Abstract
A power supply terminal assembly for use on a board and having a construction which is capable of improving working efficiency in mounting the power supply terminal assembly onto the board and enhancing mechanical strength of each power supply terminal. The power supply terminal assembly for supplying electric power to a back wiring board (BWB) comprises a terminal block formed with a pair of through slits and a screw hole at a center between the pair of through slits, and a terminal bracket bent into a U-shape and having a flat central plate portion formed therethrough with a hole corresponding to the screw hole and opposite side plate portions each formed with a plurality of press-fit terminals at an end thereof, the opposite side plate portions being inserted through the pair of through slits, respectively, and fixed thereat.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a power supply terminal assembly for supplying electric power to a board, and more particularly to a power supply terminal assembly for use on a back wiring board (BWB) of a communication device.
2. Description of the Related Art
In recent years, communication systems have been required to have a higher-density structure, a larger information-transmitting capacity, and more sophisticated capabilities, due to an upsurge in the use of data communications and the like.
Under the circumstances, each communication device tends to consume an increased amount of electric power and hence is required to be capable of handling a large current.
Further, back wiring boards (BWBs) of the communication devices keep on becoming highly multilayered, and with an increase in the layers of their multilayered structure, they are becoming thicker and thicker.
Connectors for supplying electric power to BWB are mostly of solderless connection type in which connection are established by press-fitting in a matched impedance configuration so as to allow high-frequency signals to pass therethrough.
Conventionally, electric power is supplied to a BWB based on the following constructions:
In a first construction, electric wires each having one end thereof soldered to a power terminal are inserted into respective through holes formed through a BWB for soldered connection between the electric wires and the BWB.
According to this construction, power supply capacity is determined depending on the number of the electric wires and a diameter of each electric wire which is dependent on current capacity of a power source, so that it is required to increase the number of electric wires or the diameter of each electric wire so as to make the BWB capable of handling large currents.
In a second construction, electric power is supplied through press-fit power connectors. In this case, the press-fit power connectors are embedded in a BWB, and a power source side is also provided with connectors.
According to this construction, power supply capacity is determined depending on the number of the press-fit power connectors and that of pins of each press-fit power connector, so that it is required to increase the press-fit power connectors or the connector pins in number so as to make the BWB using this construction capable of handling large currents.
A third construction is one in which a plurality of press-fit terminals are mounted separately. This construction will be described below with reference to FIGS.
6
(A) and
6
(B). FIGS.
6
(A) and
6
(B) show the construction of a press-fit terminal employed in this construction.
The press-fit terminal
10
shown in FIGS.
6
(A) and
6
(B) has a body
11
bent into a U-shape and having opposite ends thereof formed with comb teeth-shaped press-fit terminal pins
12
a
to
12
e
. Further, at a center of a flat central portion of the body
11
, there is formed a through screw hole
13
into which a screw
1
is screwed. Reference numeral
2
indicates a sectional view of the press-fit terminal
10
taken on line
6
(B)—
6
(B) in FIG.
6
A.
Next, a procedure of mounting the press-fit terminal
10
constructed as above onto a BWB will be described with reference to FIGS.
7
(A) and
7
(B). FIGS.
7
(A) and
7
(B) show a plurality of press-fit terminals mounted in the BWB. FIG.
7
(A) is a plan view, while FIG.
7
(B) is a sectional view taken on line B—B of FIG.
7
(A).
As shown in FIGS.
7
(A) and
7
(B), in wiring by the use of the press-fit terminals
10
a
to
10
e
, the press-fit terminal pins
12
a
to
12
e
of the press-fit terminals
10
a
to
10
e
are each separately inserted into a pair of through holes formed through the BWB
20
and fixed thereat. Then, the screws
1
a
to
1
e
are screwed respectively into the screw holes
13
(see FIGS.
6
(A) and
6
(B)) of the press-fit terminals
10
a
to
10
e
via crimp terminals
3
a
to
3
e
(appearing in FIG.
7
(B)) for electric wires.
Instead of using the crimp terminals
3
a
to
3
e
, the wires may be wound around the screws
1
a
to
1
e
, respectively, connection to the press-fit terminals
10
a
to
10
e.
According to the third construction, current capacity depends on the number of the press-fit terminal pins and the diameter of each connectable wire.
However, the first construction requires a structure for mounting of the mechanism. Further, when the apparatus using the BWB consumes a large amount of electric power, it is required to connect a plurality of electric wires to one terminal or use wires having a large diameter, which degrades manufacturing efficiency. Further, when the electric wires are increased in number, it is also required to increase mounting space. Moreover, an increase in thickness of the BWB can cause defective soldered connections.
The second construction using press-fit power connectors is mechanically retained by connectors, so that it is inferior in ruggedness. In addition, since this construction is a connector-type, erroneous wiring can be carried out when the number of electrodes of one press-fit power connector is identical to that of electrodes of another press-fit power connector, and hence voltage-monitoring capability is required for checking the wiring.
As far as the third construction is concerned, the body of each of the press-fit terminals used therein is formed with the screw hole having a female screw thread directly cut therein (e.g. by burring) for connection to an electric wire. The strength of this structure against tightening by a screw is dependent on thickness and material of the terminal itself, so that a small terminal as shown in FIGS.
6
(A) and
6
(B) is not reliable in strength of its body.
Further, since the terminals are mounted separately in the BWB as shown in FIGS.
7
(A) and
7
(B), manufacturing efficiency is low. Further, if terminals are arranged close to each other, a feeder to be connected or actually connected to a corresponding one of the terminals can come into contact with an adjacent terminal when it is connected or in the connected state.
Moreover, the screw hole
13
of the press-fit terminal is a through hole. Therefore, so long as a screw
1
having an appropriate length is used as shown in FIG.
8
(A), there is no problem. However, as shown in FIG.
8
(B), if a long screw if is used, there is a problem that an end of the screw damages the BWB and the terminal falls off the BWB as indicated by reference numeral
3
therein.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a power supply terminal assembly for supplying electric power to a board. The power supply terminal assembly is characterized by comprising a terminal block formed with a pair of through slits and a screw hole at a center between the pair of through slits, and a terminal bracket bent into a U-shape and having a flat central plate portion formed therethrough with a hole corresponding to the screw hole and opposite side plate portions each formed with a plurality of press-fit terminals at an end thereof, the opposite side plate portions being inserted through the pair of through slits, respectively, and fixed thereat.
It is another object of the invention to provide a power supply terminal assembly having enhanced mechanical strength of each power supply terminal.
The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate a preferred embodiment of the present invention by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is an exploded perspective view of a power supply terminal assembly according to the present invention;
FIG. 2
is a partial perspective view of a terminal block appearing in
FIG. 1
, taken on line
2
—
2
of
FIG. 1
;
FIG. 3
is a perspective view showing a bottom surface of the terminal block;
FIGS.
4
(A) to
4
(C) are views showing the construction of a terminal bracket in detail, in which:
FIG.
4
(A) is a plan view of the terminal bracket;
FIG.
4
(B) is a front view of the terminal bracket; and
FIG.
4
(C) is a side view of the terminal bracket;
FIG. 5
is a view which is useful in explaining a procedure of mounting the power supply terminal assembly onto a BWB;
FIG.
6
(A) is a view which is useful in explaining the construction of a conventional press-fit terminal;
FIG.
6
(B) is a cross-sectional view taken on line
6
(B)—
6
(B) of FIG.
6
(A).
FIGS.
7
(A) and
7
(B) are views showing conventional press-fit terminals mounted on the BWB, in which:
FIG.
7
(A) is a plan view of the mounted terminals; and
FIG.
7
(B) is a cross-sectional view taken on line
7
(B)—
7
(B) of FIG.
7
(A); and
FIGS.
8
(A) and
8
(B) are cross-sectional views which are useful in explaining a problem which can be caused by fixing the conventional press-fit terminal by a screw in which:
FIG.
8
(A) shows a case where a screw having an appropriate length is used; and
FIG.
8
(B) shows a case where a long screw is used.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will now be described with reference to the accompanying drawings.
FIG. 1
shows a power supply terminal assembly of the present invention in an exploded state.
FIG. 2
is a partial perspective view of a terminal block appearing in
FIG. 1
, taken on line
2
—
2
of the figure.
FIG. 3
shows a bottom surface of the terminal block in perspective.
The power supply terminal assembly
30
shown in
FIG. 1
is a five-electrode type. The power supply terminal assembly
30
basically includes a terminal block
31
, five terminal brackets
41
a
to
41
e
, five crimp terminal-fixing screws
51
a
to
51
e
each having a washer, and a protective cover
60
.
The terminal block
31
generally in the form of a rectangular parallelepiped is made of PBT (polybutylene terephthalate). The terminal block
31
has opposite side walls
32
a
,
32
b
protruding upward as viewed in FIG.
1
and formed with respective screw holes
35
a
,
35
b
for use in securing the protective cover
60
to the terminal block
31
by screws. Further, between the side walls
32
a
,
32
b
, four insulating walls
33
a
to
33
d
protrude upward as viewed in
FIG. 1
at equally spaced intervals in parallel with the side walls
32
a
,
32
b
. A plurality of pairs of through slits
34
a
to
34
e
in which the terminal brackets
41
a
to
41
e
are fitted respectively are formed in parallel with each other through flat portions between the insulating walls
33
a
to
33
d
and between the insulating walls
33
a
,
33
d
and the side walls
32
a
,
32
b.
Further, as shown in
FIG. 2
, formed at a center of each of the flat portions between the through slits
34
a
to
34
e
is a non-through or bottomed screw hole
37
for screwing a corresponding one of the crimp terminal-fixing screws
51
a
to
51
e
therein. Each of the screw holes
37
is integrally formed in the terminal block
31
by embedding a female-threaded cylindrical metal member therein.
Since the power supply terminal assembly
30
is symmetrically shaped, the side wall
32
a
has a projection
36
formed on a bottom surface thereof, as shown in
FIGS. 1 and 3
, for prevention of erroneous mounting of the power supply terminal assembly
30
onto a BWB. Further, as shown in
FIG. 3
, the bottom surface of the terminal block
31
has mounting holes (screw holes)
38
a
to
38
d
formed in four corners thereof, respectively, for use in mounting the power supply terminal assembly
30
onto the BWB. Rectangular and circular holes designated by reference numerals
39
a
,
39
b
, and
39
c
on behalf of the others appearing in
FIG. 3
are recesses formed when the terminal block
31
is formed.
The terminal brackets
41
a
to
41
e
appearing in
FIG. 1
are each formed by bending a flat nickel-plated plate of phosphor bronze into a U-shape, and forming a comb teeth-shaped press-fit terminal
43
comprised of six terminal pins
43
a
to
43
f
(see
FIG. 3
) at an end of each of side plate portions of the bent plate opposed in parallel to each other and a hole
42
at a center of a flat central plate portion bridging the opposite side plate portions. The crimp terminal-fixing screws
51
a
to
51
e
are each screwed into a corresponding one of the holes
42
to secure a corresponding one of the crimp terminals
71
a
to
71
e
in a manner sandwiching the same between its washer and a corresponding one of the terminal brackets
41
a
to
41
e.
The terminal pins
43
a
to
43
f
each have a root thereof formed with a slim elliptical spring portion as shown in FIG.
3
. When the press-fit terminal
43
is inserted into a through hole formed in the BWB, the spring portions of the respective terminal pins
43
a
to
43
f
fixedly secure the press-fit terminal
43
by their spring pressure.
FIGS.
4
(A) to
4
(C) show the construction of the terminal bracket in detail. FIG.
4
(A) is a plan view of the terminal bracket, FIG.
4
(B) a front view of the same, and FIG.
4
(C) a side view of the same.
As shown in FIG.
4
(B), the side plate portions of the terminal bracket
41
a
each have two upper and lower portions which are different in width and formed with double wedge-shaped projections
44
a
and
44
b
projecting outward from each side edge of each of the side plate portions.
When the side plate portions of the terminal bracket
41
a
are each inserted into a corresponding one of the through slits
34
a
of the terminal block
31
in such a manner that the press-fit terminal pins
43
a
to
43
f
protrude from the bottom surface of the terminal block
31
as shown in
FIG. 3
, the double wedge-shaped projections
44
a
and
44
b
of the side plate portions of the terminal bracket
41
a
are brought into engagement with the through slits
34
a
. When a force is applied to the terminal bracket
41
a
in a direction opposite to a direction of insertion in this state, the projections
44
a
,
44
b
wedge into wall surfaces of the through slits
34
a
, whereby the terminal bracket
41
a
is fixedly fitted in the terminal block
31
.
Further, the protective cover
60
appearing in
FIG. 1
has two through holes formed through opposite end portions thereof, respectively, and cover-fixing screws
61
a
,
61
b
are inserted through the through holes and screwed into the screw holes
35
a
,
35
b
, respectively.
In assembling the component parts into the power supply terminal assembly
30
, the press-fit terminals
43
of each of the terminal brackets
41
a
to
41
e
are inserted into a corresponding one of the pairs of through slits
34
a
to
34
e
of the terminal block
31
, and then the terminal brackets
41
a
to
41
e
are each pushed downward as viewed in
FIG. 1
until the central plate portion thereof formed with the hole
42
is brought into contact with a surface of the terminal block
31
formed with a corresponding one of the pairs of through slits
34
a
to
34
e
. This causes the terminal brackets
41
a
to
41
e
to be fitted in the terminal block
31
such that the press-fit terminals
43
are projected from the bottom surface of the terminal block
31
as shown in FIGS.
3
and
4
(B).
Then, the crimp terminals
71
a
to
71
e
are fixed to the terminal brackets
41
a
to
41
e
, respectively, by screwing the crimp terminal-fixing screws
51
a
to
51
e
into the respective screw holes
37
of the terminal block
31
.
Thereafter, the protective cover
60
is attached to the terminal block
31
by screwing the cover-fixing screws
61
a
,
61
b
into the screw holes
35
a
,
35
b
, respectively.
Next, description will be made of a procedure of mounting the power supply terminal assembly
30
constructed as above onto a BWB
80
, with reference to
FIG. 5
which is useful in explaining the mounting procedure.
It should be noted that mounting of the power supply terminal assembly
30
onto the BWB
80
is carried out with the protective cover
60
and the crimp terminal-fixing screws
51
a
to
51
e
removed therefrom, so as to carry out cabling.
First, in this state, the projection
36
of the power supply terminal assembly
30
is caused to be aligned over a dovetail hole
81
of the BWB
80
, and at the same time the press-fit terminals
43
are each caused to be aligned over a corresponding one of a plurality of through holes
83
, and then the terminal block
31
is pushed into the BWB
80
.
When the terminal block
31
is pushed in, the mounting holes
38
a
to
38
d
(see
FIG. 3
) are in a state aligned with through holes
82
a
to
82
d
of the BWB
80
, respectively. Then, bolts, not shown, are inserted into the through holes
82
a
to
82
d
from behind the BWB
80
and screwed into the mounting holes
38
a
to
38
d
, respectively, to thereby secure the power supply terminal assembly
30
to the BWB
80
.
Subsequently, the crimp terminals
71
a
to
71
e
each having a cable (not shown) connected thereto are fixed to the terminal brackets
41
a
to
41
e
, respectively, by the respective crimp terminal-fixing screws
51
a
to
51
e
, and then the protective cover
60
is attached to the terminal block
31
.
Further, a power supply capacitor, not shown, is mounted between a power terminal, not shown, of the power supply terminal assembly
30
and a ground, not shown, of the same behind the BWB
80
.
According to the embodiment described above, the power supply terminal assembly
30
for supplying electric power to the BWB
80
is comprised of the terminal block
31
having the pairs of through slits
34
a
to
34
e
formed therethrough and the screw holes
37
each formed between a corresponding one of the pairs of through slits
34
a
to
34
e
, and the terminal brackets
41
a
to
41
e
each bent into the U-shape and having the flat central plate portion formed with the hole
42
corresponding to the screw hole
37
and the opposite side plate portions each formed with the plurality of press-fit terminal pins
43
a
to
43
e
at an end thereof, the opposite side plate portions being inserted through a corresponding one of the pairs of through slits
34
a
to
34
e
and fixed thereat.
This embodiment makes it possible to complete a power supply terminal assembly
30
by fitting terminal brackets
41
a
to
41
e
in a terminal block
31
and then mount the same onto a BWB, which enhances working efficiency as well as mechanical strength of each power supply terminal. Further, since the number of the terminals can be determined based on power supply capacity, the freedom of design is increased.
Further, the pairs of through slits
34
a
to
34
e
are separated by the respective insulating walls
33
a
to
33
d
, so that even when the terminals are arranged close to each other, a feeder to be connected or actually connected to any one of the terminals is prevented from contacting an adjacent terminal as in the prior art.
Moreover, the screw holes
37
are non-through ones or bottomed, so that even if long screws are used as crimp terminal-fixing screws
51
a
to
51
e
, the screws are prevented from damaging the BWB by ends thereof, and the terminals are prevented from falling off.
Still further, the side plate portions of the respective terminal brackets
41
a
to
41
e
each have the two portions which are different in width and formed with the double wedge-shaped projections
44
a
,
44
b
at each side edge, so that it is possible to fixedly fit the terminal brackets
41
a
to
41
e
in the terminal block
31
.
Although in the above embodiment, the power supply terminal assembly is a five-terminal type, it goes without saying that the present invention can be applied to a power supply terminal assembly having any number of terminals.
Further, although in the embodiment, the power supply terminal assembly is mounted on the BWB, this is not limitative, but the invention can also be applied to a power supply terminal assembly for supplying electric power to a board of general type.
As described above, the power supply terminal assembly of the invention is constructed such that the press-fit terminal brackets are fitted in the slits of the terminal block. Therefore, working efficiency in mounting the power supply terminal assembly onto a board is improved, and mechanical strength of each power supply terminal is also enhanced.
Further, since the number of the terminals can be determined based on power supply capacity, the freedom of design is increased.
The foregoing is considered as illustrative only of the principles of the present invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and applications shown and described, and accordingly, all suitable modifications and equivalents may be regarded as falling within the scope of the invention in the appended claims and their equivalents.
Claims
- 1. A power supply terminal assembly for supplying electric power to a board, comprising:a terminal block formed with a pair of through slits and a screw hole at a center between said pair of through slits; a terminal bracket bent into a U-shape and having a flat central plate portion formed therethrough with a hole corresponding to said screw hole and opposite side plate portions each formed with a plurality of press-fit terminals with an elliptical spring portion at an end thereof, said opposite side plate portions being inserted through said pair of through slits, respectively, and fixed thereat, and each of said opposite side plate portions being formed by two portions which are different in width and each formed with a wedge-shaped projection.
- 2. A power supply terminal assembly according to claim 1, wherein insulating walls are formed on opposite sides of said pair of through slits.
- 3. A power supply terminal assembly according to claim 1, wherein said screw hole is a non-through one.
- 4. A back wiring board on which a power supply terminal assembly having a plurality of press-fit terminals is mounted, said power supply terminal assembly, comprising:a terminal block formed with a pair of through slits and a screw hole at a center between said pair of through slits; a terminal bracket bent into a U-shape and having a flat central plate portion formed therethrough with a hole corresponding to said screw hole and opposite side plate portions each formed with a plurality of press-fit terminals with an elliptical spring portion at an end thereof, said opposite side plate portions being inserted through said pair of through slits, respectively, and fixed thereat, and each of said opposite side plate portions being formed by two portions which are different in width and each formed with a wedge-shaped projection.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 11-049319 |
Feb 1999 |
JP |
|
US Referenced Citations (6)
Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 0 054 377 |
Jun 1982 |
EP |
