Field of the Invention
[0001] This invention generally relates to the art of electrical connections and, particularly,
to an electrical terminal assembly.
Background of the Invention
[0002] Generally, an electrical connector typically includes an insulating or dielectric
housing mounting one or more conductive terminals, such that the connector is mateable
with a complementary mating connector or other connecting device. In turn, the terminals
of the connector are engageable with the terminals of the complementary mating connector
or other connecting device. The terminals of the connectors are terminated to a variety
of electrical components which are to be connected, such as electrical wires, flexible
circuits, printed circuit boards or the like.
[0003] The terminals of electrical connectors can take a wide variety of configurations.
For instance, a female terminal typically has a socket or receptacle for receiving
a pin contact or male terminal. The male and female terminals are telescoped to establish
an electrical connection therebetween. There often is a balancing between a desire
for a good, positive electrical connection between the mating terminals and a desire
to minimize the insertion forces involved in mating the terminals. In other words,
if a pair of mating terminals have a high degree of interference fit therebetween,
the electrical connection is very positive. On the other hand, the high interference
fit results in high insertion or mating forces and, when a connector has an increased
number of mating terminals, the total insertion forces may be undesirably high.
[0004] Another problem in designing electrical terminals of the character described arises
when it is desirable to plate the contacting portions or surfaces of the terminals
with a highly conductive plating material to increase the conductivity between the
terminals. When a male terminal is mated with a female terminal, the interference
or friction fit therebetween has a tendency to scrape the plating material off of
the contacting portions of the terminals. In order to alleviate this problem, more
expensive plating can be used which reduces the frictional forces. For instance, while
a tin-based plating might be adequate to establish increased conductivity, tin is
a soft material and is prone to be easily scraped off of the terminal. A harder plating
material, such as gold or palladium/nickel, can be used, but these plating materials
add considerably to the costs of the terminals. Lubricants also have been used to
reduce the frictional forces, but the application of lubricants also adds considerable
costs by adding fabrication steps, and the lubricant can evaporate or become solidified
and lose its lubricating properties.
[0005] The present invention is directed to solving this myriad of problems in an electrical
terminal assembly which has various sections to control the insertion forces between
the mating terminals, and with only portions of the terminals plated that have minimal
interference or friction fits therebetween.
Summary of the Invention
[0006] An object, therefore, of the invention is to provide a new and improved terminal
assembly, including a male electrical terminal, of the character described.
[0007] In the exemplary embodiment of the invention, the electrical terminal assembly is
shown to include a female terminal having a forward mating end of a given cross-sectional
dimension. The female terminal has a contact section rearwardly of the forward mating
end, the contact section having a cross-sectional dimension smaller than that of the
forward mating end. As disclosed herein, the forward mating end is generally cylindrical,
and the contact section is formed by a pair of flexible contact arms on diametrically
opposite sides of the female terminal.
[0008] A male terminal has a forward contact end of a given cross-sectional dimension and
which is adapted for engagement within the contact section of the female terminal.
The male terminal has an interference section rearwardly of the forward contact end,
the interference section having a cross-sectional dimension greater than that of the
forward contact end for establishing an interference fit within the forward mating
end of the female terminal. As disclosed herein, the forward contact end and the interference
section of the male terminal are generally cylindrical. The invention contemplates
that at least a portion of only the forward contact end of the male terminal be plated
with a conductive material.
[0009] By plating only the forward contact end of the male terminal, the interference section
rearwardly of the forward contact end can have a high interference fit with the forward
mating end of the female terminal without creating a problem of scraping the plating
material off of the male terminal. In other words, the interference fit between the
plated forward contact end of the male terminal and the contact section of the female
terminal can be considerably less than the interference fit between the interference
section of the male terminal and the forward mating end of the female terminal.
[0010] Other objects, features and advantages of the invention will be apparent from the
following detailed description taken in connection with the accompanying drawings.
Brief Description of the Drawings
[0011] The features of this invention which are believed to be novel are set forth with
particularity in the appended claims. The invention, together with its objects and
the advantages thereof, may be best understood by reference to the following description
taken in conjunction with the accompanying drawings, in which like reference numerals
identify like elements in the figures and in which:
FIGURE 1 is a top plan view of an electrical terminal assembly according to the invention,
including a male terminal and a female terminal in unmated condition, and with a portion
of the female terminal broken away to facilitate the illustration;
FIGURE 2 is a side elevational view of the terminal assembly of Figure 1, again in
unmated condition;
FIGURE 3 is a side elevational view of the assembly, with a section through the female
terminal, and with the terminals in mated condition;
FIGURE 4 is a top plan view of the terminals in mated condition, with a section through
the telescoped area of the terminals;
FIGURE 5 is a vertical section taken generally along line 5-5 of Figure 3; and
FIGURE 6 is a vertical section taken generally along line 6-6 of Figure 3.
Detailed Description of the Preferred Embodiment
[0012] Referring to the drawings in greater detail, and first to Figures 1 and 2, an electrical
terminal assembly, generally designated 10, is shown according to the invention. The
assembly includes a female terminal, generally designated 12, and a male terminal,
generally designated 14. Each of the terminals includes two pairs of crimp arms 16
and 18. Crimp arms 16 are adapted for clamping onto the conductors of a respective
electrical cable, and crimp arms 18 are adapted for clamping onto the outer insulating
cladding of the cable to provide strain relief therefore.
[0013] Female terminal 12 has a forward, generally cylindrical mating end 20 of a given
cross-sectional dimension or diameter. Generally, a contact section is provided rearwardly
of forward mating end 20 and having a cross-sectional dimension smaller than that
of the forward mating end. Specifically, a pair of flexible cantilevered contact arms
22 define the contact section of the female terminal. Distal ends 22a of the flexible
contact arms define contact portions which engage the male terminal, as described
hereinafter. In essence, the distance between distal ends 22a of flexible contact
arms 22 define the cross-sectional dimension of the contact section which is less
than the cross-sectional dimension or diameter of forward mating end 20. Female contact
12 is stamped and formed of conductive sheet metal material, and the inside surfaces
of distal ends 22a of flexible contact arms 22 can be plated with a highly conductive
plating material.
[0014] Male terminal 14 includes a forward contact end 24, an interference section 26 rearwardly
of the forward contact end, and a stop section 28 rearwardly of the interference section.
The male terminal is stamped and formed of conductive sheet metal material and each
of the forward contact end 24, interference section 26 and stop section 28 are generally
cylindrical. As can be seen clearly in Figures 1 and 2, interference section 26 has
a cross-sectional dimension or diameter greater than that of forward contact end 24,
and stop section 28 has a cross-sectional dimension or diameter greater than that
of the interference section. For mating purposes described hereinafter, the different
diameters between interference section 26 and stop section 28 defines a stop shoulder
30 therebetween, circumferentially about the male terminal.
[0015] Figures 3 and 4 show female terminal 12 and male terminal 14 in mated condition.
When mated, forward contact end 24 of the male terminal engages distal ends 22a of
flexible contact arms 22 of the female terminal, and interference section 26 of the
male terminal establishes an interference or friction fit within forward mating end
20 of the female terminal. Stop section 28 of the male terminal has a greater diameter
than contact end 20 of the female terminal, so that stop shoulder 30 of the male terminal
abuts against the forward end of the female terminal to define the limit position
of insertion or mating between the terminals.
[0016] The invention contemplates that at least a portion of only the forward contact end
24 of male terminal 14 be selectively plated with a conductive material to increase
the conductivity between the mating terminals. Although it is contemplated that at
least a portion of contact end 24 be selectively plated, the entire forward contact
end can be plated so that the terminals can be omni-directionally mated.
[0017] By selectively plating only the forward contact end 24 of the male terminal, an interference
or friction fit between interference section 26 of the male terminal and forward mating
end 20 of the female terminal can be as high as is desired or practical, without having
the plating on contact end 24 of the male terminal scraped off of the terminal during
mating. This can be seen in comparing Figures 5 and 6. It can be seen in Figure 5
that forward mating end 24 of male terminal 14 is spaced inwardly from the interior
of the female terminal, except for engagement with distal ends 22a of flexible contact
arms 22 of female terminal 12. These engaging forces can be considerably less than
the interference fit between interference section 26 of the male terminal and mating
end 20 of the female terminal as is shown in Figure 6. With this unique structural
combination, the insertion forces operating between the terminals during mating can
be controlled or varied as desired, without regard to the highly conductive plated
portions of the terminals which, in essence, are remote or divorced from the interference
portions of the terminals.
[0018] It will be understood that the invention may be embodied in other specific forms
without departing from the spirit or central characteristics thereof. The present
examples and embodiments, therefore, are to be considered in all respects as illustrative
and not restrictive, and the invention is not to be limited to the details given herein.
1. An electrical terminal assembly (10), comprising:
a stamped and formed female terminal (12) having a forward mating end (20) of a given
cross-sectional dimension, and
a contact section (22) rearwardly of said forward mating end (20) and having a cross-sectional
dimension smaller than that of the forward mating end; and
a stamped and formed male terminal (14) having a forward contact end (24) of a given
cross-sectional dimension and adapted for engagement within the contact section (22)
of the female terminal (12),
an interference section (26) rearwardly of said forward contact end (24) and having
a cross-sectional dimension greater than that of the forward contact end for establishing
an interference fit within the forward mating end (20) of the female terminal (12),
and
wherein at least a portion of only said forward contact end (24) of the male terminal
(14) being selectively plated with a conductive material.
2. The electrical terminal assembly of claim 1 wherein said forward contact end (24)
of the male terminal (14) is generally cylindrical.
3. The electrical terminal assembly of claim 2 wherein said contact section of the female
terminal (12) includes at least one flexible contact arm (22) for engaging the cylindrical
contact end (24) of the male terminal (14).
4. The electrical terminal assembly of 3, including a pair of said flexible contact arms
(22) on diametrically opposite sides of the female terminal (12).
5. The electrical terminal assembly of claim 1 wherein said forward mating end (20) of
the female terminal (12) and said interference section (26) of the male terminal (14)
are generally cylindrical.
6. The electrical terminal assembly of claim 5 wherein said forward contact end (24)
of the male terminal (14) is generally cylindrical.
7. The electrical terminal assembly of claim 6 wherein said contact section of the female
terminal (12) includes at least one flexible contact arm (22) for engaging the cylindrical
contact end (24) of the male terminal (14).
8. The male electrical terminal of claim 1, including a stop section (28) on the male
terminal (14) rearwardly of the interference section (26) thereof and having a cross-sectional
dimension greater than that of the interference section and greater than that of the
forward mating end (20) of the female terminal (12).
9. The electrical terminal assembly of claim 8 wherein said forward contact end (24),
said interference section (26) and said stop section (28) of the male terminal (14)
all are generally cylindrical.
10. The electrical terminal assembly of claim 9 wherein said contact section of the female
terminal (12) includes at least one flexible contact arm (22) for engaging the cylindrical
contact end (24) of the male terminal (14).
11. The electrical terminal assembly of 10, including a pair of said flexible contact
arms (22) on diametrically opposite sides of the female terminal (12).
12. The electrical terminal assembly of claim 11 wherein the forward mating end (20) of
the female terminal (12) is generally cylindrical.