U.S. patent number 3,897,129 [Application Number 05/400,951] was granted by the patent office on 1975-07-29 for connector encapsulating device and method.
This patent grant is currently assigned to Minnesota Mining and Manufacturing Company. Invention is credited to John A. Farrar, Jr..
United States Patent |
3,897,129 |
Farrar, Jr. |
July 29, 1975 |
CONNECTOR ENCAPSULATING DEVICE AND METHOD
Abstract
A method and device are described for encapsulating a multiple
wire electrical connector in a viscous encapsulating material. A
socket adapted to closely fit around the connector is filled with a
predetermined quantity of the encapsulating material. The connector
is pressed into the socket so that some of the encapsulating
material is forced from the bottom of the socket to the surface of
the connector adjacent the opening to the socket through
passageways along the sides of the socket. This encapsulating
material is then spread over the connector, which spreading may be
facilitated by flexing flaps on the housing toward the opening.
Inventors: |
Farrar, Jr.; John A. (Atlanta,
GA) |
Assignee: |
Minnesota Mining and Manufacturing
Company (St. Paul, MN)
|
Family
ID: |
23585677 |
Appl.
No.: |
05/400,951 |
Filed: |
September 26, 1973 |
Current U.S.
Class: |
439/204; 29/858;
29/868; 174/138F; 29/872 |
Current CPC
Class: |
H02G
15/10 (20130101); Y10T 29/49176 (20150115); Y10T
29/49201 (20150115); Y10T 29/49194 (20150115) |
Current International
Class: |
H02G
15/10 (20060101); H01r 007/04 (); H01r
013/52 () |
Field of
Search: |
;339/94,99,115,116,117,218 ;174/138F |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Moore; Richard E.
Attorney, Agent or Firm: Alexander, Sell, Steldt &
Delahunt
Claims
Having thus described the present invention with reference to two
illustrated embodiments, what is claimed is:
1. A method for encapsulating a connector having side walls
extending between first and second ends which connector
electrically interconnects a plurality of wires projecting from its
first end, said method including the steps of:
providing a housing having a socket with a bottom opposite an
unrestricted open end, the socket being adapted to closely fit
around and completely receive the side walls and second end of the
connector with its first end facing the open end of the socket and
the wires extending therethrough, said housing having a plurality
of projections defining, when a connector is within the socket,
passageways extending from the bottom of the socket to the open
end, and having a quantity of viscous, water restricting
electrically insulating encapsulating material in the socket, the
quantity being at least sufficient to fill the socket for a
predetermined distance over the connector after the second end of
the connector is positioned at the bottom of the socket;
positioning the connector in the socket with its second end
adjacent the bottom thereof and in contact with the encapsulating
material;
pressing the positioned connector into the open end of the socket
with sufficient pressure to force the encapsulating material into
and through the passageways to deposit a portion of the
encapsulating material at the first end of the connector; and
spreading the portion of the encapsulating material at the first
end of the connector around the wires and over the first end of the
connector.
2. The method of claim 1 wherein the housing has a pair of flaps
hingedly mounted along one edge in opposed relationship to the
housing on opposite sides of the open end of the socket, and said
spreading step includes the step of pressing the flaps toward the
open end to help in spreading the potting compound across the first
end of the connector.
3. In combination, a connector including an insulative body having
side walls extending between first and second ends and a plurality
of internal wire receiving channels, a plurality of wires in said
channels and a plurality of conductive contact elements mounted in
said body member, said contact elements having spaced fingers in
resilient engagement with the wires to electrically interconnect
wires in the channel in a predetermined pattern; a housing having a
socket with a bottom opposite an unrestricted open end, the socket
closely fitting around and completely receiving the side walls and
second end of the connector with its first end facing the open end
and the wires extending therethrough; and a quantity of viscous
electrically insulating water restricting encapsulating material
within the socket around said connector.
4. A device for encapsulating an electrical connector having side
walls extending between first and second ends and electrically
interconnecting a plurality of wires projecting from its first end,
said device comprising a housing having a socket with a bottom
opposite an unrestricted open end, the socket being adapted to
closely fit around and completely receive the side walls and second
end of a said connector with the first end of the connector facing
the open end and the wires projecting therethrough, said housing
having a plurality of projections defining, when a said connector
is positioned within the socket, channels extending from the bottom
of the socket to the open end, and a pair of flaps hingedly mounted
along one end in opposed relationship at the open end of the
housing.
5. The device of claim 4 wherein each of said flaps has a
projection defining a generally cylindrically concave arcuate
surface adjacent the open end of the socket with one edge of the
surface being aligned with the outer extreme of the surface
defining the socket and the surface extending through an arc of
about 90.degree. over the open end.
Description
BACKGROUND OF THE INVENTION
This invention relates to the encapsulation of electrical
connectors, and in one aspect to encapsulating telephone circuit
wire connectors in a viscous encapsulating material.
The plurality of connectors used to interconnect wires of a
telephone circuit such as in a pressurized or non-pressurized
splice case, or a telephone pedestal, must be protected from
corrosion caused by moisture which may enter the splice case or
pedestal. This protection cannot be conveniently provided by
encapsulation in a self-curing encapsulating material within an
enclosure as is taught in U.S. Pat. Nos. 2,862,042, 2,908,744,
2,967,795 and 3,419,669 for use in splicing underground cables,
because of the bulk of the enclosure and the virtual impossibility
of re-entry to change a connection. While encapsulation of such
connectors in a removable encapsulating material within an
enclosure as is taught in U.S. Pat. application No. 376,285 would
afford re-entry, such encapsulation is also not desirable because
of the bulk of the enclosure and because re-entry to a single
connector within the enclosure requires opening of the entire
housing, and disturbing and repairing of the encapsulating material
around connectors adjacent the one in which the change is to be
made. Such connectors have been individually encapsulated in a
viscous encapsulating material by placing the encapsulating
material and wired connector into a flexible bag, working the
encapsulating material around the connector, and securing the open
end of the bag about the wires leading to the connector which are
formed into a bundle. This system, however, requires a large amount
of the encapsulating material relative to the volume of the
connector, and sufficient length in each of the spliced wires to
form the bundle. Also, the proper distribution of the encapsulating
material around the connector is dependent on the operator's skill,
and the resulting encapsulated connector is large compared to the
size of the connector so that it fills valuable space within the
splice case or pedestal.
SUMMARY OF THE INVENTION
According to the present invention there is provided a simple,
efficient and dependable method for individually encapsulating
connectors in a splice case or pedestal. A connector encapsulated
by this method is efficiently protected from moisture while it may
be easily re-entered and re-encapsulated without disturbing
adjacent connectors. The amount of the expensive encapsulating
material required to encapsulate a connector is small compared to
encapsulating the connector in a grease bag (e.g., the same
connector may be encapsulated in 20 grams of encapsulating material
with the present invention compared to about 110 grams of
encapsulating material when a grease bag is used). Also, the wires
entering the connector need not be formed into a bundle, and the
size of the encapsulated connector is small which allows a given
size of splice case or pedestal to contain a larger amount of
connectors.
An encapsulated connector according to the present invention is
enclosed on five sides within a close fitting socket in a housing,
with the wires electrically interconnected by the connector
projecting through the opening to the socket (i.e., by close
fitting we mean having less than about 1/16 inch clearance around
the connector inside the housing). A quantity of viscous
electrically insulating encapsulating material surrounds the
connector within the socket to protect the connector from
moisture.
The housing for receiving the connector has a plurality of
projections defining passageways extending from the bottom of the
socket to its open end. To encapsulate a connector, viscous, water
insoluble, electrically insulating encapsulating material is placed
in the socket in a quantity at least sufficient to fill the socket
for a predetermined distance over a connector fully enclosed
therein. The connector is pressed into the socket with sufficient
pressure to force a portion of the encapsulating material through
the passageways to the exposed end of the connector, after which
that portion of the encapsulating material is spread around the
wires and over the first end of the connector.
Viscous, water insoluble electrically insulating encapsulating
materials which are particularly suitable include those having a
high dielectric strength and thixotropic properties, with a static
viscosity in about the 1 to 11/2 million centipoise range, and a
penetrometer reading in the range of 200 to 300. Examples include a
silicone grease sold under the designation "DC-2" by Dow Corning,
Inc.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be further described with reference to the
accompanying drawing wherein like numbers refer to like parts in
the several views, and wherein:
FIG. 1 is a plan view of a connector encapsulated in a housing
according to the present invention;
FIG. 2 is an elevational side view, partially in section, of the
present invention as illustrated in FIG. 1;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2
illustrating movement (in phantom) of a flap on the housing;
and
FIGS. 4 and 5 are end views of the present invention partially in
section, illustrating an alternate embodiment of the housing, with
FIG. 5 illustrating movement of a flap on the housing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 through 3 there is illustrated a connector
10 encapsulated in a viscous encapsulating material (illustrated by
stippling in FIG. 1) within a housing 14. The housing 14 has a
socket 15 with a bottom opposite an unrestricted open end 17. The
socket 15 fully receives and closely fits around four planar side
walls 18 and an inner or second end 19 of the rectangular connector
10, while a first or exposed end 20 of the connector 10 faces the
open end 17 of the socket 15. A plurality of wires 22 electrically
interconnected by the connector 10 project through the open end 17
of the socket 15. A quantity of viscous, electrically insulating,
water restricting encapsulating material surrounds the connector 10
within the socket 15, including a layer of the encapsulating
material over its first end 20 and around the projecting wires
22.
The connector 10 is of the type disclosed in U.S. Pat. No.
3,708,779, the disclosure whereof is incorporated by reference
herein. Briefly the connector 10 has separable insulative body
portions 24 defining (when assembled) a plurality of internal wire
receiving channels. A plurality of conductive contact elements 30
which are slotted to define resilient wire receiving fingers are
mounted in one of the body portions with the slots aligned with the
channels. The wires 22 to be elecrically interconnected are
positioned within the part of the channels defined in one of the
body portions 24 and the connector 10 is assembled to resiliently
engage the fingers of the contact elements 30 with the wires to
electrically interconnect them in a predetermined pattern.
The housing 14 is a one piece molding of a polymeric material,
preferably polypropylene. The housing 14 includes rectangularly
disposed side walls 32, end walls 34 and a bottom wall 36, the
inner surfaces of which define the socket 15. The side and end
walls 32 and 34 have inwardly extending projections or ribs 38
which extend longitudinally at right angles to the bottom wall 36
and define, when a connector 10 is in the socket 15, passageways
between the connector 10 and walls 32 and 34 extending from the
bottom to the open end of the socket 15.
To encapsulate the connector 10 the craftsman selects the housing
14 which is adapted to accept the connector 10. The socket 15
contains a quantity of viscous encapsulating material sufficient to
at least fill the socket to a predetermined distance over the
connector 10 after the connector is fully enclosed within the
socket 15 with its second end 19 contacting or closely spaced from
the bottom wall 36. The connector 10 is then positioned in the
socket 15 with its second end 19 adjacent the bottom wall 36 and in
contact with the encapsulating material. The craftsman presses the
connector 10 into the open end 17 of the socket 15 with sufficient
pressure to force the encapsulating material into and through the
passageways and deposit a portion thereof at the first end 20 of
the connector 10. The craftsman then spreads the portion of
encapsulating material between the connector 10 and the open end 17
of the socket 15 around the wires and over the first end 20 of the
connector 10 to complete the encapsulation thereof.
The housing 14 includes flaps 40 hingedly mounted along one edge in
opposed relationship at the open end 17 of the socket 15. The flaps
40 are integrally formed with the walls 32 and 34 and hinged
thereto via a thin strip of the housing material at the base of a
generally V-shaped groove 42. As the connector is pressed into the
socket 15 the portion of the encapsulating material extruded
through the passageways will be deposited adjacent the flaps 40.
The craftsman may then flex the flaps 40 inwardly to the position
illustrated in FIG. 3 to help spread that portion of the
encapsulating material around the wires 22 and over the first end
20 of the connector 10.
FIGS. 4 and 5 illustrate an alternate structure for the housing 10
generally designated by the numeral 45 in which is positioned a
rectangular connector 46 similar to the connector 10 and having
side walls 47, a second or inner end 48 and a first or exposed end
49 from which project a plurality of electrically interconnected
wires 50. Like the housing 10, the housing 50 has rectangularly
disposed side walls 52, end walls (not shown) and a bottom wall 56,
the inner surfaces of which define a socket 58 fully enclosing the
connector 46. The side and end walls 52 each have inwardly
extending projections or ribs 60 which extend longitudinally at
right angles to the bottom wall 56, and define, when a connector is
in the socket 58, passageways extending from the bottom to the open
end of the socket 58. Like the housing 14, the housing 45 has
hinged flaps 64 for spreading encapsulating material over a
connector which has been pressed into the socket 58. Unlike the
flaps 40, however, the flaps 64 attached to the side walls 52 have
generally triangular projections 66 with generally cylindrically
concave arcuate surfaces 68 adjacent the open end of the socket 58.
One edge of the surface 68 on each projection 66 is aligned with
the outer extreme of the surface defining the socket 58 or inner
surface of the adjacent side wall 52, and from this edge the
surface 68 tends through an arc of about 90 degrees. As the portion
of the encapsulating material displaced by the connector 46 is
extruded through the passageways toward the opening of the socket
58, it will contact and be deflected by the surfaces 68 on the
projections 66 over the first end 49 of the connector 46. The
craftsman may then flex the flaps 64 inwardly as illustrated in
FIG. 5 to further spread the encapsulating material around wires 50
projecting from the first end 49 of the connector 46.
* * * * *