Note: Descriptions are shown in the official language in which they were submitted.
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ELECTRICAL CONTACT ARRANGEMENT
Description
Field of the Invention
The invention relates generally to electrical terminals and,
more particularly, to a multiple-contact configuration for
electrical engagement of a blade terminal within a mating
receptacle.
Hackctround of the Invention
Historically, various types of assemblies have been developed
for electrically and conductively interconnecting devices to be
electrically energized to sources of electrical power. For
example, it is well known to provide various spatial areas of
residential, commercial and industrial establishments with
electrical receptacle units permanently (through fuses, circuit
breakers or other emergency shut-c>ff elements) conductively
connected to one or more sources of main utility power. Each of
'the receptacle units typically comprises one or more engaging
assemblies often referred to by the colloquial term "female
receptacle."
These receptacle units are conventionally mounted in
stationary walls or, alternatively, in the case of modern and
modular office furniture systems, in moveable wall panels or even
within work surfaces. Devices to b~ electrically energized often
comprise receptacle plugs having two or more prongs or blade
terminals adapted to be conductively engaged within the female
receptacles. The prongs or blade terminals are conventionally
referred to by the colloquial terms "male" plugs, prongs, blades
or terminals. The receptacle plugs are typically interconnected
to thQ circuitry of the device so as to be energized by wires
axtandi,ng through flexible Insulat:Lve cards o.r the like.
This type of male/female electrical, interconnection
configuration to provide removable or releasable conductive
engagement is utilized in a myriad of electrical connector
arrangements. ~'or exampl.e, in addition to electrical energization
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of relatively large and discrete devices (such as lamps,
televisions, stereos, typewriters, etc.), male/female
interconnection configurations are also utilized internally in
electrical devices such as computers and associated peripherals.
In addition, male/female electrical interconnection arrangements
are also utilized in a number of other applications, such as
internal circuit wiring for electrical apparatus of modular office
systems and the like.
In the design of male/female electrical interconnection
configurations, it is of primary importance to provide a secure
and stationary electrical contact between the conductive surfaces
of the elements of the electrical receptacle and the conductive
surfaces of the prongs or blade terminals. It is also of primary
importance to provide surface connections having relatively little
resistance. In view of the foregaing, various types of interfaces
have been developed for engaging males prongs or blade terminals
with mating female receptacles. For example, it is known to
utilize an opposing pair of can~tilev~er beams within the female
receptacle, which provide a single point of contact on each side
of an inserted male terminal. Other known arrangements include the
use of single cantilever spring pressure, backed with a steel or
similar spring supported within a plastic housing. This type of
arrangement will conventionally provide a single point of contact
at the electrical interface.
It has become known that it is preferable to provide as many
interface points of contact as is reasonably possible, while still
maintaining a releasable engagement. For example, an arrangement
for providing four contact points is disclosed in Sasaki et al,
U.S, patent No. 4,795,379 issued January 3, 19$9, The Sasaki et
al patent refers to 'the coxicept 'that it has bean known to utilize
certain types of electrical connections in computers,
telecammunications equipment and other data processing equipment,
which are in the form of a receptacle contact having four resilient
cantilever contact members ex~tenda.ng forwardly from ~a base. The
contact members are adapted to provide an electrical connectian
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with a tab contact inserted from the front of the receptacle unit.
The tab contact is electrically engaged by four leaves from four
directions. The four leaves can be arranged as opposing pairs,
with each pair arranged orthogonally.
In this type of arrangement, electrical engagement is made
with the tab contact at four points, thereby increasing reliability
of the receptacle contact relative to a contact arrangement having
only two contact points. Sasak:i et al also explains that a problem
can wise in that a possibility of an incomplete electrical
engagement can be caused by foreign matter on the surface of the
tab contact. In addition, one of the pairs of contact members may
engage the edge surfaces of the tab contact. The edge surfaces of
the tab contact are typically the surface edges formed when the
contact is made by stamping a sheet off: conductive material. Ths
surfaces are often rough in comparison with the planar rolled or
formed surface of the sheet, and thus have a lower contact
reliability. Accordingly, these contact members may not provide
a reliable electrical connection, and a greater insertion force may
be required at the time of insertion.
As an improvement, Sasaki et al describes a receptacle contact
having opposed leaf spring members formed by two parallel plates
linked through a U-shaped portion extending between adjacent sides
of the leaf spring members. The leaf spring members include first
spring arms and second spring arms formed integrally with the
spring members.
The first spring arms and second spring arms are opposed to
each ether, and outer contact and inner contact members axe formed
at the free ends of the spring arms, which are also opposed to each
other. Additional contact members are located to the rear of the
first set of contact members. The spring arms extend side by side
from the leaf spring mombars, with thQ outer contact members being
slightly twice thca width of the inner contact members. The contact
members are arcuate tn facilitate insertion of a tab contact
therebetween.
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The receptacle contact described in Sasaki et al is formed by
stamping from a suitable metal sheet having the desirable
conductive and spring characteristics. The stamping process is
performed by shaping the metal sheet in an appropriate
configuration, and then folding the spring arms to the shape
required, while folding another portion into a U-shape. In use,
the tip of a tab contact can be inserted into the space between
the outer contact members opposed to each other at the front
portion of the receptacle contact. Upon insertion, upper and lower
surfaces of the contact are brought into a wiping engagement with
the outer contact members. Accordingly, foreign matter on upper
and lower surfaces of the contact is removed. When the contact is
inserted further, the upper and lower surfaces which have been
cleaned by the outer contact members are else wipingly engaged by
the inner contact members. Tn this manner, a relatively greater
electrical connection reliability bei:~ween the tab contact and the
inner contact members is provided. Tn addition, the outer contact
members and inner contact members are in electrical engagement with
upper and lower planar surfaces of the tab contact, and not with
side surfaces which may comprise the cut edge surfaces of the
contact. Accordingly, this decreases the force needed to insert
the contact unto the receptacle contact, thereby improving
reliability of electrical connection.
In addition, the length of the spring arms which provide the
contact force created between the outer contact members and the tab
contact, is longer than the length of the spring arms which provide
the contact force between inner contact members and the tab
cantact. Accordingly, the insertion farce is reduced by reducing
the contact force created between the tab contact and 'the outer
contact members, which clQan the upper and lower surfaces of 'the
tab contact. Tn 'this manner, the initial insertian force of the
tab contact within the outer contact members is less than the
insertion force of 'the inner contact members.
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Summary of the Invention
Tn accordance with the invention, an electrical receptacle
apparatus includes at least one electrical receptacle adapted to
conductively engage a blade terminal or the like. The electrical
receptacle includes upper means extending forwardly, and having a
lower surface with at least first, second and third upper contact
locations formed thereon. Lower means are provided which extend
forwardly and are conductively interconnected to and positioned
substantially directly below the upper means. The lower means
include an upper surface with at least first, second and third
lower contact locations formed thereon. The receptacle is sized
and configured so that the blade terminal is insertable between the
upper means and the lower means, and is adapted to conductively
contact the receptacle at the first, second and 'third upper and
lower contact locations. Tn this manner, at least six conductive
electrical contact locations are formed with the receptacle.
The first, second and third upper contact locations can be
foamed substantially within a single upper plane, and form a
triangular configuration within the upper plane. Corresponding3y,
the first, second and third lower contact locations can be formed
substantially within a single lower plane, and form a triangular
configuration with the lower plane. each of the first, second and
third lower contact locations can be respectively positioned
substantially directly below each of the first, second and third
upper contact locations.
The upper means can include at least one pair of upper lateral
arms extending forwardly. The upper means can also include an
upper bridge portion positioned transversely across forward
portions of the upper lateral arms. The upper bridge portion and
'the upper lateral arms form an upper spatial area. Upper
cantilever means are positianed substantially within 'the upper
spatial area, and comprise an arcuate shags forming the first upper
contact location thereon. Correspondingly, the second and third
upper contact locations can ?ae formed at interconnections of the
upper bridge portion and the upper lateral arms.
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The lower surface of the upper means is formed of a lower
surface of the upper cantilever means and lower surfaces of the
upper bridge portion and upper lateral arms. The upper cantilever
means is conductively interconnected to the upper lateral arms.
The lower means can include at least one pair of lower lateral
arms extending forwardly. A lower bridge portion can be positioned
transversely across forward portions of the lower lateral arms, and
conductively interconnect the lower lateral arms. The lower bridge
portion and lower lateral arms form a lower spatial area. Lower
20 cantilever means are provided which are positioned substantially
within the lower spatial area, and comprise an arcuate shape
forming the first lower contact location thereon. Correspondingly,
the second and third lower contact locations are formed at
interconnections of the lower bridge portion and lower lateral
arms.
The upper surface of the lower means is formed of an upper
surface of the lower cantilever means and upper surfaces of the
lower bridge portion and the lower lateral arms. The lower
cantilever means is conductively interconnected to the lower
lateral arms.
In accordance with another aspect of the invention, the
receptacle apparatus can comprise four of the electrical
receptacles, The apparatus can further comprise a connecting beam
central to and symmetrically located relative to the four
receptacles. The connecting beam can be rectangular in
configuration and integrally connected to each of a pair of
secondary connecting portions through a pair of L1-shaped connecting
portions foamed at ends of the connecting beam. Each of the
secondary connecting portions can farm an integral support pardon
for the upper means,
The apparatus can further camprise a common 'terminal input
channel conductively interconnected to the receptacles. A pair of
crimp wings can be farmed at lateral sides thereof.
The upper means can include a pair of upper substantially
parallel and elongated lateral arms extending forwardly. An upper
bridge portion can be conductively interconnected to the upper
lateral arms. The upper bridge portion and the upper lateral arms
form an upper spatial area. An upper cantilever member can extend
forwardly within the upper spatial area, and comprise an arcuate
shape forming a first upper contact location on a lower surface
thereof. The upper bridge portion can be angled upwardly in a
forward direction, and the upper lateral arms can be angled
downwardly in a forward direction. The intersections of the upper
bridge portion and upper lateral arms form the second and third
upper contact locations. The upper cantilever member can be
resilient in structure and comprise a rear downwardly angled
portion integrally connected at a forward portion thereof to a
forward upwardly angled portion. Ths: first upper contact location
can be formed at an interface of the rear downwardly angled portion
and the forward upwardly angled portion.
Brief Description of the Drawings
An illustrative embodiment of the invention will now be
described with respect to the drawings, in which:
FIG. 1 is a perspective view of an electrical contact
arrangement in accordance with the invention;
FIG. 2 is a tog plan view of the contact arrangement shown in
FIG. l;
FIG. 3 is a side view of the contact arrangement shown in FIG.
1;
FIG. 4 is an and view of the contact arrangement shown in FIG.
1;
FIG. 5 is an underside view from the opposing side of the
contact arrangement shaven in FIG. 2;
FIG. 6 is a sectional view of the contact arrangement, taken
along section lines 6-5 of FIG. 2;
FIG. 7 is a side view showa.ng an example insertion arrangement
of a blade terminal into the contact arrangement;
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FIG. 8 is an illustration similar to FIG. 7, showing further
insertion of the blade terminal; and
FIG. 9 is an illustration similar to FIG. 8, showing final
position insertion of the blade terminal.
Detailed Description of the Preferred Embodiment
The principles of the invention will now be disclosed, by way
of example, in an electrical contact unit 100 as illustrated in
FIGS. 1-9. Although the electrical contact unit 100 described in
subsequent paragraphs herein includes a series of four electrical
receptacles, the principles of the invention are not limited, in
any manner, to the use of four such receptacles. For example, the
principles of the invention can be included within one electrical
receptacle or any other desired number. The contact unit 100 as
described herein provides at least six locations of contact with
respect to the electrical engagement of male blade terminals with
the electrical contact unit. In addition, the contact unit 100 in
accordance with the invention also provides a preferable triangular
positioning of contact points so as to maintain a stable electrical
connection between the blade terminals and the elements of the
electrical receptacles.
Referring primarily to FIG. 1, the electrical contact unit
3.00 includes a series of four electrical receptacles 102, 104, 106
and 108. As illustrated in FIGS. 1-6, each electrical receptacle
102, 104, 106 and 108 includes an outer, elongated and upper
cantilever member 110, and an opposing lower cantilever member 112.
The upper cantilever members 110 each include a pair of lateral and
parallel elongated arms 114 integrally cannected at their forward
ends lay a bridge portion 116. Correspondingly, each of the lower
cantilever members 3,12 includes corresponding lateral arms 118
integrally connected at their forward ends by a lower bridge
portion 120.
As .illustrated primarily in FTGS. 3 and 6, the upper lateral
arms 1'.4 have a sla.ght downwardly angled configuration, while the
~5 upper bridge portion 116 is angled slightly upwardly. With this
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configuration, a contact surface or edge 122 is formed at the
integral interface between the upper bridge portion 116 and each
of the lateral arms 114. Correspondingly, the lateral arms 118 of
the lower cantilever members 112, as further illustrated in FIGS.
3 and 6, are angled slightly upwardly, while the lower bridge
portion 120 is angled slightly downwardly. With this
configuration, a contact surface or edge 124 is provided at the
interface between the integrally connected lateral arms 118 and
lower bridge portion 120.
As shown primarily in FIGS. 2 and 5, the lateral arms 110 and
bridge portion 116 of the upper cantilever members 110 form an
arcuate spatial area 126 internal to the arms 114 in bridge portion
116. A similar spatial area 127 is formed by the lateral arms 118
and lower bridge portion 120 of the lower cantilever members 112.
With respect specifically to FTG. 2, each of the receptacles 102,
104, 106 and 108 also include an inner and upper cantilever member
128 which extends forwardly within the spatial area 126 formed by
the lateral arms 114 and bridge portion 116. An opposing inner
cantilever member 130 is formed within the corresponding spatial
area 127 of the lower cantilever members 112 and also extends
forwardly. As illustrated primarily in FTGS, 3 and 6, each of the
upper cantilever members 128 is resilient in structure and has a
rear downwardly angled portion 132 integrally connected at the
forward portion thereof to a forward upwardly angled portion 134.
Correspondingly, each of the lower and inner cantilever members 130
includes a rear upwardly angled portion 136 integrally connected
at its forward end to a forward downwardly angled portion 138. The
interface between the rear downwardly angled portion 132 and
forward upwardly angled portion 134 of the upper cantilever me~~ber
128 forms a contact surface or edge 140. Correspondingly, a
contact surface or edge 142 is formed at the interface between the
integrally connected rear upwardly angled portion 136 and forward
downwardly angled portion 138 of the lower cantilever members 130.
The opposing upp~ar and lower cantilever members 110, 112 and
the oppasing inner cantilever members 128, 130 are flexible and
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resilient in nature so as to be appropriately flexed when a male
blade terminal (illustrated in FIGS. 7-9) is inserted between the
opposing cantilever members. Tn addition, as will be further
apparent from additional description herein, the contact surfaces
122 and 140 associated with the upper cantilever member 110 and the
upper cantilever member 128 form a triangular contact surface
configuration with the male blade terminal. Correspondingly, the
contact surfaces 124 and 142 form an opposing triangular contact
surface configuration, thereby providing six points of contact
between the electrical receptacles 102, 104, 106 and 108 and the
inserted male blade terminal. This triangular configuration
provides a substantial stabilizing effect to the interconnection
between the male blade terminal and the electrical receptacles,
while correspondingly providing six points of contact.
Referring again primarily to 1~TGS. 1, 2 and 5, the four-
roceptacle unit 100 includes a connecting beam 144 central to and
symmetrically located relative to 'the receptacles 102, 104, 106
and 108. The connecting beam 144 is rectangular in configuration
and is integrally connected to each of two secondary connecting
portions 146 by means of a U-shaped connecting portion formed at
each of the ends of the connecting beam 144. Each of the secondary
connecting portions l46 also forms an integral inner support
portion for the upper cantilever members 110 and the upper
cantilever members 128.
~s further illustrated in FIGS. ~., 2 and 5, the four-
receptacle unit 100 includes a common terminal input channel 150
having a pair of crimp wings 152 integrally formed at the lateral
sides of the channel 150. The channel 150 includes a transition
portion 154 integrally connecting the common terminal input channel
150 with the connecting ba~am 1,44. In addition to the foregoing,
the receptacle unit 100 also includes a pair of tabs 156 each
formed on one side of each of the secondary connecting portions
146, These tabs 156 provide a means for controlling positioning
of the ~~boxes~~ formed by 'the surfaces of the aonnec~ting beam 144,
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secondary connecting portions 146 and U-shaped connecting portions
148.
The use of the electrical contact unit 100 with corresponding
insertion of a male blade terminal 158 will now be described with
respect to FIGS. 7-9. The male blade terminal or tab contact 158
may, as illustrated in FIGS. ~, 8 and 9, include tapered surfaces
at its forward portion for purposes of facilitating insertion into
the electrical receptacles 102, 104, 106 and 108. For purposes of
illustration, FIGS. 7, 8 and 9 only illustrate one of the
electrical receptacles 106. The forward portion of the blade
terminal 158 is first inserted into the spatial area formed between
the upper bridge portion 116 and lower bridge portion 120. As 'the
blade terminal 158 is inserted, upper and lower surfaces of the
terminal 158 will contact the upper contact surfaces 122 and lower
contact surfaces 124 formed at the interface between the bridge
portions 116, 118 and the lateral arms 114, 118. As the blade
terminal 158 is further :inserted, the forward portion of the
terminal 158, at its upper and lower surfaces near the central
portions thereof, will engage in an electrical contact with the
contact surfaces 140, 142 formed at the interfaces of the
integrally connected downwardly angled portion 132 and forwardly
and upwardly angled portion 134 of the upper cantilever member 128,
and the interface between the integrally connected upwardly angled
portion 136 and downwardly angled portion 138.
As previously described, the upper contact surfaces 122 and
140 provide a triangular configuration, with three locations of
electrical contact. This triangular configuration provides a
substantial stabilizing effect which prevents .relatively poor
contact if the interconnection between the male blade terminal 158
and the corresponding receptacle is jarred or otherwise subjected
to a '°rocking" movement. Correspondingly, the three locations of
lower contact provided by the contacts surfaces 124 and 142 provide
a corresponding triangular contact surface configuration opposing
the upper contact configuration. With the three paints of lower
contact, the interconnea~tion and engagement between the male blade
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terminal 158 and the corresponding electrical receptacle is
provided with six locations of contact. Still further, if the male
blade terminal 158 is appropriately sized relative to the relative
positioning of the bridge portions 116, 120, the surfaces of the
bridge portions 116, 7.20 will provide a °'wiping" engagement with
the central portion of the upper and lower surfaces of the blade
terminal 158. This wiping engagement will ensure that the central
portion of the blade terminal 158 which will be in electrical
contact with the upper and inner cantilever member 128 and lower
and inner cantilever member 130 will be free from any foreign
matter as a result of the "cleaning'° function carried out by the
bridge portions 116, 118. With the six locations of contact
~>rovided for each of the electrical receptacles 102, 104, 7.06 and
108, the electrical current-carrying capability of the receptacles
is greatly improved. Tn addition, with respect to the particular
four-receptacle unit 100 illustrated herein, four receptacles are
provided with the necessity of only a single wire crimp
configuration in an integral terniinal, thereby providing an
efficient use of space within a connector system. Still further,
the triangular positioning of the three locations of contact on
each of the upper and lower surfaces of the male blade terminal
provide a substantially "steady°' platform for the male blade
terminal 158.
As apparent from the foregoing, the electrical connector unit
100 can be formed from a suitable metal sheet by means of stamping
and forming the unit 100, with the sheet having the appropriate
conductive and spring and resiliency characteristics. Such a
stamping process can be achieved by utilizing a suitably formed
metal sheet, and then fo:Lding over the elements forming the upper
cantilev~ar members 110 and the secondary connecting portions 146.
7a will be apparent to those sk:Llled in the pertinent arts
that other embodiments of electrical contact units in accordance
with the invention can be achieved. That is, the principles of an
electrical contact unit ~.n accordance with the invention era a~ot
limited to the specific embodiment described herein. For example,
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an electrical contact unit in accordance with the invention can
employ other than four electrical receptacles. It will be apparent
to those skilled in the art that modifications and other variations
of the above-described illustrative embodiment of the invention may
be effected without departing from the spirit and scope of the
novel concepts of the invention.
