U.S. patent number 3,723,948 [Application Number 05/196,290] was granted by the patent office on 1973-03-27 for electrical component.
This patent grant is currently assigned to Minnesota Mining and Manufacturing Company. Invention is credited to Gail A. Anderson, Gerald A. Wyatt.
United States Patent |
3,723,948 |
Wyatt , et al. |
March 27, 1973 |
ELECTRICAL COMPONENT
Abstract
An electrical connector or circuit component capable of being
rapidly attached to insulated wires and having a base member
channeled to receive mutually electrically insulated wire
conductors, e.g., insulated copper wires carried in a non-metallic
sheath, such as used to carry current in machines or buildings,
conductive contact elements capable of being forcefully applied to
wire conductors to make electrical contact without preliminary
stripping of the insulation or severing of the wire conductor, an
insulating body member retaining the elements and including parts
thereon characterizing the circuit component, and holding means to
hold together the base and body.
Inventors: |
Wyatt; Gerald A. (Shoreview,
MN), Anderson; Gail A. (St. Paul, MN) |
Assignee: |
Minnesota Mining and Manufacturing
Company (St. Paul, MN)
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Family
ID: |
22724774 |
Appl.
No.: |
05/196,290 |
Filed: |
November 8, 1971 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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73414 |
Sep 18, 1970 |
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Current U.S.
Class: |
439/107;
439/405 |
Current CPC
Class: |
H01R
4/2429 (20130101) |
Current International
Class: |
H01R
4/24 (20060101); H01r 009/08 () |
Field of
Search: |
;339/14,95,97-99,164 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGlynn; Joseph H.
Parent Case Text
This is a continuation application of Ser. No. 73,414, filed Sept.
18, 1970, and now abandoned.
Claims
What is claimed is:
1. An electrical component capable of making solderless electrical
connection to insulated wire conductors of a three conductor cable
covered with a nonmetallic sheath without requiring preliminary
stripping of the insulation or severing of the wire conductors and
having a wire-receiving base member, a body member engageable with
the base and containing conductive contact elements having
projecting therefrom resilient contact plate portions slotted to
provide an open-mouth slot adapted for forceful entry of a wire
conductor, and holding means for holding the base and the body
together; wherein the base member comprises: an elongate insulating
block longitudinally channeled along one face to provide an
enlarged channel at one end capable of receiving the sheath covered
wires, said channel branching into three smaller intermediate
channels capable of receiving insulated wires exposed by cutting
away a short portion of said sheath, and converging again as an
enlarged channel at the other end, the central intermediate channel
being substantially straight and the outer intermediate channels
being oppositely arcuate, said intermediate channels each having a
wire-supporting floor and parallel walls, said base being
transversely grooved across each of said intermediate channels with
grooves of adjacent channels being nonaligned to provide grooves in
said floor and walls for slidably receiving an appropriate one of
said contact plate portions with the mouths of the slots of said
plate portions centered in relationship to the wire-supporting
floors of the intermediate channels, whereby insulated wire
conductors supported in said intermediate channels are brought into
permanent positive electrical connection with appropriate contact
plate portions upon engagement of the body with the base.
2. The electrical component of claim 1 wherein said body member
comprises an elongate insulating block having a surface engageable
with the channeled face of said base, said block being slotted
through said surface to an opposite surface to provide at least one
pattern of holes corresponding to the projections on a 3 conductor
power plug and channeled in said surface to provide channels
adapted to support said contact elements, and wherein each of said
contact elements is further characterized by having a slotted
plug-receiving portion positioned on said contact element in its
supporting channel with said plug-receiving portion in alignment
with one of said holes.
3. An electrical component as defined in claim 1 further comprising
a second base member as therein defined engageable with said body,
said electrical component being capable of making solderless
electrical connection between corresponding insulated wire
conductors of non-metallic sheath-covered three-conductor cables
supported in each base without preliminary stripping of the
insulation or severing of the wire conductors, said body having
opposite surfaces each engageable with a base, and being slotted
through said surfaces to provide openings for containing the
contact elements, said contact elements having two oppositely
directed slotted resilient plate-like portions and being disposed
in said body to slidably insert said plate-like portions into
corresponding grooves of each base.
4. An electrical component as defined in claim 1 wherein said body
member comprises an insulating block having a first surface
engageable with the channeled face of said base, said block being
slotted through said first surface to an opposite surface to
provide at least one hole for receiving the base of a light bulb
and channeled in said first surface to provide channels adapted to
support said contact elements, and wherein the contact elements
adapted to contact wires in the outer channels of the base are
further characterized by having portions thereon for making
electrical connection with said light bulb.
5. An electrical component as defined in claim 1 wherein said body
member comprises an insulating block having a surface engageable
with the channeled face of said base, said block having thereon an
electrical switching means for opening and closing a conductive
path between two contact points, and channeled in said surface to
provide channels adapted to support said contact elements, and
wherein each of the contact elements adapted to contact wires in
the outer channels of the base is electrically connected to one of
said contact points.
6. An electrical component capable of making solderless electrical
connection to insulated wire conductors of a three conductor cable
covered with a nonmetallic sheath without requiring preliminary
stripping of the insulation or severing of the wire conductors and
having a wire-receiving base member, a body member engageable with
the base and containing conductive contact elements having
projecting therefrom resilient contact plate portions slotted to
provide an open-mouth slot adapted for forceful entry of a wire
conductor, and holding means for holding the base and the body
together; wherein one of said base member and body member is formed
with wall means for defining an enlarged channel at one end of the
component capable of receiving the sheath covered wires, said
channel branching into three smaller intermediate channels capable
of receiving insulated wires exposed by cutting away a short
portion of said sheath, and converging again as an enlarged channel
at the other end of said component, the central intermediate
channel being substantially straight and the outer intermediate
channels being oppositely arcuate, and wherein said base has
wire-supporting means including wire-supporting surfaces extending
along a portion of each of said intermediate channels relative to
an appropriate one of said contact plate portions with the mouths
of the slots of said plate portions centered in relationship to the
wire-supporting means of said base while permitting entry of said
contact plate portions into said base beyond said wire-supporting
surfaces, whereby insulated wire conductors supported in said
intermediate channels are brought into permanent positive
electrical connection with appropriate contact plate portions upon
engagement of the body with the base.
7. The electrical component of claim 6 wherein said body member
comprises an elongate insulating block having a surface mating with
the face of said base, said block being slotted through said
surface to an opposite surface to provide at least one pattern of
holes corresponding to the projections on a 3 conductor power plug
and channeled in said surface to provide channels adapted to
support said contact elements, and wherein each of said contact
elements is further characterized by having a slotted
plug-receiving portion positioned on said contact element in its
supporting channel with said plug-receiving portion in alignment
with one of said holes.
Description
This invention relates to electrical components, and in particular
to electrical components that are easily installed on mutually
insulated wire conductors carried in a non-metallic sheath without
preliminary stripping of the insulation, and without the necessity
of severing the wire conductor. A typical use of the electrical
component lies in electrical wiring, e.g., in the wiring of
prefabricated homes, trailer homes, and the like.
Conventionally, wire conductors are attached to electrical
connectors or circuit components by screw or other kinds of
pressure fasteners. These methods are time consuming and may
require stripping or cutting of the wire conductor such as shown in
U.S. Pat. No. 3,510,822. Electrical components are known which
eliminate the necessity of stripping the insulation from the wire
conductor. For example, see U.S. Pat. No. 2,873,435 which discloses
an electrical device which can be attached to a wire end without
stripping. This, however, is limited to use on wire conductor ends
and, therefore, requires that the wire conductor be severed.
This invention is intended to provide an electrical component to
which speedy, simple, lasting, low resistance connections can be
made to wire conductors without requiring stripping or severing of
the wire conductor. The components can be rapidly and easily
installed with considerably less time and effort than that required
for conventional devices for the same purpose. The electrical
components of the invention are small in size as compared to the
conventional devices, thus take less storage space, and also less
space upon installation.
The invention contemplates making connections to wires having
diameters in the A.W.G. wire size range of Number 14 through Number
10. The electrical components of the invention utilize, for making
electrical connections with wire conductors wires in the
aforementioned range, an arrangement similar to that disclosed in
U.S. Pat. No. 3,012,219. In this arrangement one or more wire
conductors are supported on a transversely slotted surface and a
connector or bridge member including at least one slotted
conductive plate is forced onto the wire conductors and into the
slotted base. The plate pierces insulation on the wire conductors
and enters into firm contact with the wire conductor. The plate is
thin and resilient so that the jaws defining the slots resiliently
spread apart and exert compression on the wire. Connections made in
this manner have been tested and found to have a very low
resistance and to maintain their high conductivity through repeated
mechanical stresses, temperature or pressure changes, exposure to
moisture or the passage of electric current.
The arrangements disclosed in the abovementioned patent, however,
has been generally limited to making connections between wires, or
to connections at terminal ends of wires. U.S. Pat. No. 3,258,733
recognizes that the arrangement can be used for the purpose of
connecting together, without severing, parallel individual wires,
but fails to disclose connections to parallel wires bound in a
unitary bundle, e.g., a three wire power cored carried in a
none-metallic sheath.
The present invention provides an electrical component with a novel
base arrangement which is channeled to receive and separate three
wires while maintaining substantially equal tension on each of the
wires. The outermost channels are oppositely arcuate to permit each
of the wires to be positively aligned with the appropriate slot in
the connector plate. Surprisingly, the central wire remains
substantially straight when the outer wires are separated and
placed in the arcuate channels, and each wire lies substantially
centered in its respective channel.
The principles of the invention will now be further described and
illustrated by reference to the accompanying drawing and
wherein:
FIG. 1 is a perspective view of an electrical component useful as
an electrical outlet and showing parts thereof in exploded
form;
FIGS. 2 and 3 are partial sectional views taken approximately at
line 2--2 as indicated in FIG. 1, which illustrate a segment of the
base and slotted conductive plate in elevation in two stages of
application to an insulated wire;
FIG. 4 is a plan view showing the lower face of the upper or body
portion of the electrical component of FIG. 1 with contact elements
in place therein and wires, shown in broken lines, held in the
elements;
FIG. 5 is a perspective view of another embodiment of the present
invention in exploded form;
FIG. 6 is a perspective view of an electrical component useful as a
lamp socket and showing a further embodiment of the invention as
applied to a cable; and
FIG. 7 is a perspective view showing yet another embodiment of the
present invention, i.e., a switch.
The preferred electrical component shown in FIG. 1 comprises a
novel elongate insulating base 10 formed of suitable insulating
material, e.g., phenolic resin, conductive contact elements 20, 21
and 22, to make electrical connection with wire conductors carried
in the base, a body 40 capable of containing the contact elements
and engageable with the base and a clamp 50 for holding the body
and base together. The base 10 is longitudinally channeled to
provide channel 12, having dimensions for receiving the sheath
covered cable, which branches into three separate wire-supporting
channels, 13, 14, and 15, and converges again into a single channel
34 for supporting the sheath covered cable. The outer channels, 13
and 15, are oppositely arcuate to separate the wires. Channels 13,
14, and 15 preferably have a centrally depressed floor to provide
for centering of wires of various sizes carried therein. Normally,
in use, inner channel 14 will carry a ground wire, which may be a
bare wire, and outer channels 13 and 15 will carry insulated
conductor wires. The walls and floor of each of channels 13, 14,
and 15 are transversely grooved to provide respectively a thin
groove, 16, 17, and 18, perpendicular to the channel. For
conventional use, i.e., in standard locations and areas, inner
channel 14 will be approximately 11/2 inch long with channels 13
and 15 slightly longer.
Three conductive contact elements, 20, 21, and 22, one for each of
the wire-receiving channels, are provided. The conductive contact
elements are made of a resilient electrically conductive sheet
material, e.g., spring brass, and include thin conductive plates
23, 24, and 25 projecting therefrom. The plates are of
substantially the same thickness as that of the transverse grooves
provided in each channel and are slidably movable and insertable
within the grooves.
Each thin plate, e.g., plate 24 shown in greater detail in FIG. 2
and FIG. 3, is deeply slotted to provide slot 27 and legs 28. The
narrow edges defining the slot 27 are generally parallel and
include a smoothly diverging terminal portion defining a
wire-accepting opening.
As shown in FIG. 2, when the thin plate 24 is positioned into its
respective groove 18, the slot 27 will be in alignment with and
above a wire 47 lying on the channel floor 54. As the plate 24 is
forced into the groove 18, the ends of the legs 28 come into
contact with the wire 47 in the channel. Upon further insertion,
the wire 47 enters the narrower portion of the slot 27 and the
opposing edges of the legs 28 cut into and through the insulation
ayer 30 around the conductor 29. The narrow edges of the legs 28
deform the metal conductor 29 as shown in FIG. 3, and at the same
time the legs are resiliently spread apart from their original
position. This spreading is not sufficient to overcome the elastic
strain point of the metal when the component is applied to wires. A
connection results in which the legs, attempting to spring back to
their original position, exert a continued pressure against the
wire. The width of groove 18 must be sufficient to receive the legs
when separation occurs on connection with large wires.
In the preferred embodiment the conductive plates are 0.250 inch in
width measured from the outer narrow edges of the legs, and the
narrow portion of the slot has an opening of 0.050 inch. For use
with wires in the size range of No. 14 to No. 10, the groove must
be wide enough to permit clearance of the separated legs resulting
from connection with No. 10 wire.
Conductive contact elements 20 and 21, used to make contact with
current carrying conductor wires carried in channels 13 and 15, may
be cut from a flat sheet of metal to form a blank which is folded
to the design as shown in FIG. 1. Conductive contact element 22,
normally used to make contact with a ground wire carried in channel
14, may also be cut from such a sheet of metal to form a blank
which can be folded to the desired shape, or grounding receptacles
32 or 33 may be separately cut and attached later, e.g., by
riveting or welding as shown. Element 22 has openings, similar to
those found in conventional electrical fixtures, provided in
attaching ears 26 at opposite ends for mounting.
The conductive contact elements are shaped and constructed so as to
have receptacle portions which are aligned with the holes of the
duplex electrical device of the body 40. Power receptacles 35
consist of metal leafs slotted to receive the conventional contact
bars of a power plug. The slots have a smoothly diverging terminal
portion and an initially smaller opening at the mouth which
increases approaching the base, to provide a spring action for
better contact with the contact bars of a power plug. Grounding
receptacles 32 and 33 are resilient, substantially U-shaped
conductive elements having the legs closer at the ends than at the
base, adapted to apply pressure sufficient to cause electrical
contact on the grounding portion of a power plug when inserted.
Body member 40 shown in FIG. 1, formed of a suitable insulating
material, is shaped to engage base 10. In the preferred embodiment
base 10 fits fully within a cavity in body 40. The cavity is
characterized by having substantially perpendicular walls and depth
corresponding to that of the base 10. For ease of assembling of the
base into body, one end of base 10 may differ in shape from the
opposite end as indicated by stepped sides 48 of base 10, so that
base 10 can only be put into the body in one way, thus insuring the
proper alignment of the wire contact plates with their respective
grooves.
Body 40, as shown in FIG. 4, is channeled to provide channels 36
and 37 which contain the conductive elements 22 and 21
respectively. The contact elements may be supported in their
respective channels without fastening, or may be fastened in fixed
position within body 40 by conventional means, e.g., by screws or
be constructing the channels with dimensions which prevent the
removal of the elements.
To install the connector to the wires of a 3 conductor cable, a
small portion of the non-metallic sheath of the cable 42 is cut
away, e.g., preferably less than one and one half inch, exposing
the three insulated conductors 45, 46, and 47. The three insulated
conductors are separated into the three wire receiving channels of
the base 10. The body 40, containing the conductive elements, is
aligned over the base 10 in the proper manner as hereinbefore
described, and forced by hand or a suitable tool into engagement
with the base while simultaneously making permanent electrical
contact with all three conductors.
Body 40 and base 10 are thereafter held together by clamp 50 shown
in FIG. 1. A channel 41 in body 40 and depressions 44 in the base
are provided to contain the clamp. Clamp 50 may be cut from a flat
sheet of metal such as from steel and folded as shown to give
biasing tabs 51 having a shape capable of providing a biasing force
on the base into the body, and a grounding contact element 52 which
passes through hole 43 through body 40 and opening 49 in element
22, and is folded back on over the edges of the opening to prevent
withdrawal therefrom and to ground clamp 50. A hole 53 in clamp 50
is provided to permit attachment of conventional electrical
component wall coverplates.
FIG. 5 shows another embodiment of the present invention used for
connecting one set of insulated wires to another which may be used
for providing branch lines from a main electrical circuit or
connecting together terminal ends of two cables. This embodiment
comprises two base members 10a and 10b which fit into opposing
cavities of body member 60 containing conductive contact elements
61, 62 and 63, and twin clamps 64 for holding the bases within the
body. Both ends of each of the conductive contact elements are
slotted as hereinbefore described in connection with FIG. 1 to
pierce the insulation and make contact with wire conductors.
FIG. 6 shows yet another embodiment of the invention comprising a
wire receiving and separating base member 65 assembled with a lamp,
fuse, or circuit breaker socket type body member 66 containing
conductive contact elements (not shown) having conventional
portions thereon which contact the socket and center plug of the
lamp, fuse, or circuit breaker and slotted portions which pierce
the insulation and make electrical contact with the conductors of
wire 67.
FIG. 7 shows still another embodiment of the invention comprising
the hereinbefore described wire receiving and separating base
member 73 assembled with a switch type body member 70 and
containing conductive contact elements (not shown) which are
connected to either terminal of a conventional switch 75 contained
in body 70. A ground contact element 72 also useful for mounting is
provided. The body 70 and base 73 are held together by clamp pair
74. When the switch is in the open position the contact elements
are electrically isolated from one another. In closed position the
contact elements are electrically connected together providing a
conductive path between the wire conductors carried in the outer
curved channels of the base. The opposite end of cable 71 to which
the switch is connected may have one conductor connected to a
current source and the other to an electrical device, in a
conventional use. A separate line would then connect the circuit
device to the remaining line of the current source.
It is to be understood that use of this connecting means to make
electrical contact with a circuit component is not limited to the
electrical components disclosed herein but is equally adapted for
use with other types of connectors and circuit components such, for
example, as modular lights, fuse boxes, and similar devices. The
wire separating base and wire contact plates disclosed herein will
be common to all the electrical components and the body will be
characteristic of the desired device.
It is also to be understood that the foregoing description is
illustrative only and that numerous changes can be made in the
described embodiments without departing from the spirit of the
invention as set forth in the claims.
* * * * *