U.S. patent number 3,860,316 [Application Number 05/377,154] was granted by the patent office on 1975-01-14 for electrical connecting devices for terminating cords and methods of assembling the devices to cords.
This patent grant is currently assigned to Western Electric Company, Incorporated. Invention is credited to Edwin Charles Hardesty.
United States Patent |
3,860,316 |
Hardesty |
January 14, 1975 |
ELECTRICAL CONNECTING DEVICES FOR TERMINATING CORDS AND METHODS OF
ASSEMBLING THE DEVICES TO CORDS
Abstract
A one-piece plug for terminating a cord to connect electrically
the cord to components in a telephone apparatus is constructed with
features advantageous to the assembly of the cord with the plug.
The plug has a dielectric housing molded with a cord-input aperture
in the one end thereof. The jacket is removed from a leading
portion to expose individually insulated conductors. Then an end
portion of the cord is inserted into the cord-input aperture in the
housing until individual conductors are received in
conductor-receiving troughs and until the leading end of the jacket
abuts a shoulder formed internally of the housing. Forces are
applied to a jacket anchoring member formed integrally of the
housing to partially disconnect it from the housing and move it
into engagement with the jacket. Another portion formed integrally
with the housing is reformed into a strain relief element in
engagement with the conductors to provide strain relief for the
conductors. Flat blade-like terminals are inserted into the
dielectric housing to move internal contacting portions thereof
through the insulation and into engagement with the conductors.
External contacting portions of the terminals engage associated
components of the telephone apparatus when the plug is inserted
thereinto.
Inventors: |
Hardesty; Edwin Charles (Perry
Hall, MD) |
Assignee: |
Western Electric Company,
Incorporated (New York, NY)
|
Family
ID: |
27007696 |
Appl.
No.: |
05/377,154 |
Filed: |
July 6, 1973 |
Current U.S.
Class: |
439/344; 439/460;
439/425 |
Current CPC
Class: |
H01R
24/62 (20130101); H01R 13/501 (20130101); H01R
13/5829 (20130101); H01R 13/50 (20130101) |
Current International
Class: |
H01R
13/58 (20060101); H01R 13/50 (20060101); H01r
013/54 () |
Field of
Search: |
;339/91,97,98,99,176MF,103,107 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Frazier; Roy D.
Assistant Examiner: Hafer; Robert A.
Attorney, Agent or Firm: Somers; E. W.
Claims
What is claimed is:
1. An electrical connector for terminating a cord having a
plurality of insulated conductors and for making electrical contact
external to the connector, which comprises:
an unipartite dielectric housing, with internal surfaces thereof
defining a cavity that opens to at least one end of the housing for
receiving an end portion of the cord, the surfaces of the housing
as formed and defining the cavity substantially enclosing the
entire end portion of the cord, with at least one portion of the
surfaces defining the cavity being movable relative to the
remainder of the surfaces defining the cavity at least partially
into the cavity for engaging portions of the cord to secure the
cord within the housing and to prevent unintended lateral and
longitudinal movement thereof the housing also including a
plurality of terminal-receiving openings communicating with the
cavity and the exterior of the connector; and
a plurality of electrically conductive terminals positioned within
associated ones of the terminal-receiving openings each of which
includes:
a first contact portion extending into the cavity for piercing the
insulation of and making electrical engagement with an associated
conductor of the cord; and
a second contact portion positioned within the associated
terminal-receiving opening for making electrical contact external
to the connector.
2. An electrical connector for terminating a cord having a
plurality of insulated conductors and for making electrical contact
external to the connector, which comprises:
an unipartite dielectric housing, which includes a free end and a
cavity opening to a cord-input end for receiving an end portion of
the cord, with internal surfaces of the housing as formed and
defining the cavity substantially enclosing the entire end portion
of the cord, with at least one portion of the surfaces defining the
cavity being movable relative to the remainder of the surfaces
defining the cavity at least partially into the cavity for engaging
portions of the cord to secure the cord within the housing and to
prevent unintended lateral and longitudinal movement thereof, the
housing also including conductor-receiving troughs formed in at
least a portion of the cavity and a plurality of terminal-receiving
openings communicating with the troughs and the exterior of the
connector; and
a plurality of electrically conductive terminals positioned within
associated ones of the terminal-receiving openings each of which
includes:
a first contact portion extending into the associated trough for
piercing the insulation of and making electrical engagement with
the associated conductor in the trough; and
a second contact portion positioned within the associated
terminal-receiving opening for making electrical contact external
to the connector.
3. The electrical connector of claim 2, wherein the at least one
moveable portion of the housing includes an anchoring member formed
integrally with the housing along at least a portion of the
periphery of the anchoring member such that compressive forces
applied to the anchoring member reforms the anchoring member into a
wedge-shaped element locked in engagement with the cord and the
housing to provide strain relief for the cord during use
thereof.
4. The electrical connector of claim 2, wherein the
conductor-receiving troughs open to the free end of the
housing.
5. The electrical connector of claim 2, wherein the
conductor-receiving troughs terminate in a wall forming at least a
portion of the free end of the housing to seal off the troughs from
the free end of the housing.
6. The electrical connector of claim 2, wherein a free end of the
housing extends beyond the remaining portion of the housing to
provide a bearing surface for cutting off exposed end portions of
the conductors which extend beyond the free end of the housing.
7. The connector of claim 2, wherein the terminals are blade-like
and the terminal-receiving openings include a plurality of spaced
slots opening to an external surface of the housing and
communicating with associated ones of the troughs, each of the
slots being of a size to permit the first contact portion of the
associated one of the terminals to pass therethrough.
8. The connector of claim 7, wherein the first contact portions of
each terminal includes a plurality of contact tangs which extend
through the associated one of the slots and into electrical
engagement with the conductor in the associated trough.
9. The connector of claim 7, wherein each of the terminals is
formed with barbs extending therefrom and which are positioned
within the associated one of the slots, an overall longitudinal
dimension between extremities of the barbs being slightly greater
than the longitudinal dimension of the slot which communicates with
the associated trough to facilitate the barbs of the terminal
becoming embedded in the walls of the slot when the terminals are
inserted to anchor the terminals within the housing at a
predetermined depth within the housing.
10. The electrical connector of claim 7, wherein the housing is
also formed with a plurality of spaced fins upstanding from the
external surface to which the terminal-receiving slots open, each
of the fins interposed between the longitudinal axes of two
adjacent ones of the slots, the fins capable of guiding external
contacting elements into engagement with second contact portions of
associated ones of the terminals.
11. The connector of claim 2, wherein the cord-input cavity has
approximately the same cross section as the cord with the walls of
the cavity diverging continuously from the inner portion to the
cord-input end of the connector and forming a flared inlet to avoid
sharp bends in the cord during use thereof and to facilitate
insertion of the leading end of the cord.
12. The electrical connector of claim 2, wherein the cord includes
a jacket which encloses the individual conductors, the jacket being
formed with a ridge longitudinally thereof, the cord-receiving
cavity being formed with a groove parallel with the longitudinal
axes of the troughs, the conductors of the cord inserted into the
cavity being oriented properly with respect to associated ones of
the troughs, the terminals and associated external contact elements
only when the ridge is aligned with the groove.
13. The electrical connector of claim 2, at least the free end of
which is insertable into a cavity of a jack wherein the housing is
formed with a resilient locking tab cantilevered from the free end
of the housing, the electrical connector inserted into the cavity
being in engagement with a surface defining partially the jack
cavity which is adjacent the surface of the housing to which the
second contact portions of the terminals are exposed, the locking
tab being depressed toward the housing at the free end thereof to
insert the electrical connector into the jack cavity, the tab
moving pivotally away from the housing when forces are no longer
applied to depress the free end thereof, the movement of the tab
tending to return the tab to an initial position and causing a
surface thereof to engage an edge formed transversely of the jack
cavity by surfaces defining partially the jack cavity.
14. The electrical connector of claim 13, wherein the tab is
undercut at a portion thereof which engages the edge of the jack
cavity, the undercut formed by a sloping surface which engages the
edge, the configuration of the locking tab and the cooperative
engagement thereof with the jack edge and at least one of the
surfaces defining the edge being such that when the cord of the
electrical connector is subjected to unintended forces in excess of
a predetermined magnitude, the sloping surface of the tab will ride
up over the edge to permit the electrical connector to be withdrawn
from the jack cavity.
15. The electrical connector of claim 3, wherein the anchoring
member is a conductor-restraining member which is capable of being
moved to engage individual conductors of the cord to secure the
conductors within the housing and prevent unintended lateral and
longitudinal movement thereof.
16. An electrical connector for terminating a cord having a
plurality of insulated conductors and for making electrical contact
external to the connector, which comprises:
an unipartite dielectric housing, which includes a free end and a
cavity opening to a cord-input end for receiving an end portion of
the cord, the surfaces of the housing defining the cavity
substantially enclosing the entire end portion of the cord, the
housing also including conductor-receiving troughs formed in at
least a portion of the cavity and a plurality of terminal-receiving
openings communicating with the troughs and the exterior of the
connector, the housing being formed with, at least, one portion
moveable at least partially into the cavity for engaging portions
of the cord to secure the cord within the housing and to prevent
unintended lateral and longitudinal movement thereof wherein the at
least one moveable portion of the housing includes an anchoring
member connected through a hinged portion at one end thereof and
through a severable web at the other end thereof to the housing,
such that application of forces to the anchoring member separates
the web from the housing and then causes the anchoring member to be
moved pivotally about the hinged portion to engage and anchor the
cord; and
a plurality of electrically conductive terminals positioned within
associated ones of the terminal-receiving openings each of which
includes:
a first contact portion extending into the associated trough for
piercing the insulation of and making electrical engagement with
the associated conductor in the trough; and
a second contact portion positioned within the associated
terminal-receiving opening for making electrical contact external
to the connector.
17. The electrical connector of claim 16, wherein the web of the
anchoring member is formed so that the web is separated from the
housing adjacent the housing to form an elongated extension which
is caused to assume a curved shape as the anchoring member is moved
pivotally to cause a blunt curved portion of the extension to
engage the cord thereby preventing damage to the cord as forces are
applied thereto during use of the cord.
18. The electrical connector of claim 16, wherein the cord includes
a jacket which encloses the individual insulated conductors, and
the anchoring member capable of being moved into engagement with a
jacketed portion of the cord to anchor the jacket against
unintended lateral and longitudinal movement.
19. The electrical connector of claim 16 wherein the anchoring
member is formed within an opening in the housing that communicates
with the cavity and the pivotal movement of the anchoring member
causes the anchoring member to lock under one of the walls defining
the opening to secure the anchoring member in engagement with the
cord.
20. The electrical connector of claim 18, wherein the jacket is
removed from a portion of the cord which is adjacent the free end
of the housing and the at least one moveable portion of the housing
also includes a conductor-restraining member formed integrally with
the housing along at least a portion of the periphery of the
conductor-restraining member such that compressive forces applied
to the conductor-restraining member reforms the restraining member
into a wedge-shaped element locked in engagement with the housing
and the conductors to provide strain relief for the conductors
during use of the cord.
21. A device for terminating a cord having a plurality of insulated
conductors, which comprises:
an unipartite dielectric housing,
the housing being provided with a cord-input cavity that opens to
at least one end of the housing for receiving an end portion of the
cord;
the surfaces of the housing defining the cavity substantially
enclosing the entire end portion of the cord;
the housing also being provided with a plurality of
terminal-receiving openings communicating with the cavity and the
exterior of the device; and
the housing being formed with at least one portion of the surfaces
defining the cavity being moveable relative to the remainder of the
surfaces defining the cavity at least partially into the cavity for
engaging portions of the cord to secure the cord within the housing
and to prevent unintended lateral and longitudinal movement
thereof.
22. A method of assembling a cord, which comprises individually
insulated conductors enclosed in a jacket, to a device, which
includes an unipartite housing constructed from a dielectric
material having a cavity that opens to at least one end of the
housing for receiving an end section of the cord, the surfaces of
the housing defining the cavity substantially enclosing the entire
end section of the cord, the housing also having
conductor-receiving troughs formed in the cavity and
terminal-receiving openings communicating with associated troughs,
which includes the steps of:
holding the housing;
exposing the individual insulated conductors of a predetermined
length of the one end section of the cord by removing the jacket
therefrom;
inserting the one end section of the cord into the cavity;
causing relative motion between the device and the cord to advance
the conductors into associated ones of the troughs;
applying forces to at least one portion of the unipartite housing
to move the at least one portion at least partially into the cavity
to engage and anchor the cord within the housing; and
inserting and seating terminals in the terminal-receiving openings
such that first contact portions thereof extend into the troughs
and pierce the insulation of the associated conductors to establish
an electrical connection with the conductors and to expose second
contact portions thereof externally of the housing for engagement
with external components.
23. The method of claim 22, wherein the step of applying forces to
at least one portion includes:
applying forces to one portion of the housing to disconnect one end
of the one portion from the housing and to then move the portion
pivotally to engage the one end thereof with the cord jacket;
and
applying forces to another portion of the dielectric housing to
reform the other portion to engage and lock the conductors within
the housing to prevent unintended lateral and longitudinal movement
of the conductors.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to electrical connecting devices for
terminating cords and methods of assembling the devices to cords,
and more particularly, to devices for making electrical connections
between a cord comprising flexible conductors and terminals wherein
conductive terminals are combined with one-piece dielectric members
to form plugs and methods of assembling the cord and the
devices.
2. Description of the Prior Art
In the telephone industry, increasing use is being made of modular
plug type connectors on straight and retractile handset and line
cords which are used between the base and a handset of a telephone
and between the base and a wall terminal block. In the presently
used plugs, a terminal is applied to each of a plurality of
insulated conductors contained within a jacketed length of a
retractile cordage. These terminals are mounted within a dielectric
structure which is attached securely to the associated cordage. The
dielectric portions of the plugs, which are mounted on both ends of
a length of cordage, cooperate with receptacles in the handset and
in the base of the telephone to properly align the terminals of the
plug with mating terminals within the components of the
telephone.
One presently used plug is disclosed in U.S. Pat. No. 3,699,498
issued on Oct. 17, 1972 in the names of E. C. Hardesty, C. L.
Krumreich, A. E. Mulbarger, Jr. and S. W. Walden. In this
disclosure, conductors are confined in conductor-receiving troughs
formed in a dielectric base by a cover bonded to the base. Flat
terminals are then inserted into individual grooves in the base in
a side-by-side arrangement with contact portions thereof extending
into engagement with the conductors. When the plug is inserted into
a jack of a telephone handset, portions of the terminals in the
jack engage portions of associated terminals in the plug.
Provisions in the just-identified plug for contacting the external
component may be changed to that described in a
continuation-in-part application Ser. No. 232,803 filed on Mar. 8,
1972 in the names of E. C. Hardesty, C. L. Krumreich, A. E.
Mulbarger, Jr. and S. W. Walden. There, the external contact
portions of the terminals of the plug consist of an edge exposed to
the exterior of the dielectric enclosure.
Of course, the terminals in the plugs are aligned with the contact
elements in the jack in the telephone handset. The cord conductors
in the just described system are aligned with the terminals.
The recent trend to the use of plug-in type connectors in telephone
handsets as exemplified by that shown in U.S. Pat. No. 3,617,982
has been accompanied by the use of flat telephone cords. The use of
flat cords leads toward increased manufacturing economies provided
that the plug is designed with regard for a flat cord system.
As an alternative to the bonding together of the portions of the
dielectric housing in using the plug, it would be desirable to have
a one-piece plug, into which a telephone cord end may be inserted
and secured and subsequently engaged by flat terminals moved into
terminal-receiving openings in the plug. Such a plug would also
yield manufacturing economies.
SUMMARY OF THE INVENTION
This invention provides electrical connecting devices for
terminating cords. A dielectric portion of the device can be
fabricated in one-piece by using conventional molding techniques.
The device may be assembled to a line cord or to a retractile cord
either before or after the cord is heat treated to achieve
retractile properties.
An electrical connecting device which embodies the principles of
this invention is molded to include a one-piece or unipartite
dielectric housing which includes a cavity that opens to at least
one end of the housing for receiving an end section of a telephone
cord. Unipartite or one-piece as used to describe the housing is
intended to define the housing as not divided or divisible into
parts. Moreover, the housing is molded so that no securing,
including bonding, nor moving of hinged or otherwise moveable parts
is necessary to form the cavity. The surfaces of the housing as
molded define the cavity and substantially enclose the end portion
of the cord. The plug is molded with a plurality of
terminal-receiving openings communicating with the cavity and with
the exterior of the connector. The housing is formed with at least
one portion moveable at least partially into the cavity for
engaging portions of the cord to secure the cord within the housing
to prevent unintended movement of portions of the cord. Terminals
positioned within associated ones of the terminal-receiving
openings each includes a first contact portion extending into the
cavity for making electrical engagement with the associated
conductor in the cavity and a second contact portion positioned
within the associated terminal-receiving opening for making
electrical contact external to the connector.
A method embodying the principles of this invention for assembling
connecting devices to cords for connecting electrically individual
conductors which comprise the cord to associated components
external to the device includes holding the housing and exposing
individual insulated conductors of a predetermined length of a
leading portion of the cord by removing the jacket therefrom. Then
the leading portion of the cord is inserted into a cord-input
aperture of the device and advanced to position the exposed
conductors in conductor-receiving troughs. Forces are applied to
portions formed integrally with the dielectric housing to move the
portions to engage the jacket and the conductors to secure the cord
within the device and provide strain relief for the jacket and the
individual conductors. Terminals are inserted into openings in the
device such that first contact portions extend into the troughs and
pierce the insulation to establish an electrical connection with
the conductors and to expose second contact portions of the
terminals for engagement with external components.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features of the present invention will be readily understood
from the following detailed description of specific embodiments
thereof when read in conjunction with the accompanying drawings, in
which:
FIG. 1 is a perspective view showing plugs which embody the
principles of this invention inserted into a handset and base
portion of a telephone set and into a wall terminal;
FIG. 2 is a perspective view of one of the plugs prior to assembly
of a cord and terminals therewith for purposes of clarity and
further showing an internally movable jacket strain relief member
of the plug prior to movement thereof;
FIG. 3 is a perspective view of the plug shown in FIG. 2 with
terminals inserted into the plug and with the jacket strain relief
member having been moved into engagement with the cord which has
been inserted into the plug;
FIG. 4 is an elevational view of a housing of the plug partially in
section prior to the assembly of the cord and terminals
therewith;
FIG. 5 is an elevational view partially in section showing the
jacket strain relief member of the plug after having been moved
into engagement with the jacket of the cord to provide strain
relief for the cord and a portion of the housing having been
reformed into a strain relief member in engagement with the
conductors and also showing the terminals inserted;
FIG. 6 is an elevational view showing an alternate embodiment in
which one end of the plug housing is closed;
FIG. 7 is a front end view of the plug shown in FIG. 3 and taken
along lines 7--7 thereof;
FIGS. 8 and 9 are enlarged detail views in elevation showing the
use of tools to move the jacket strain relief member and to form
the conductor strain relief member and with the tools and plug in
an inverted position from that normally used for this
operation;
FIG. 10 is an elevational view partially in section and showing the
plug inserted into a jack in a telephone set;
FIG. 11 is an enlarged detail view of a portion of latching
facilities of the plug in engagement with surfaces of a jack in the
telephone set; and
FIG. 12 is a perspective view of an apparatus which may be used to
carry out the steps of the methods of this invention.
DETAILED DESCRIPTION
1. Overall
Referring now to FIG. 1, there is shown a telephone, designated
generally by the numeral 20, which includes a base portion,
designated generally by the numeral 21, and a handset portion,
designated generally by the numeral 22. A retractile cord,
designated generally by the numeral 23, interconnects the base
portion 21 and the handset portion 22.
Each end of the retractile cord 13 is provided with a plug,
designated generally by the numeral 24, designed to be inserted
into a jack 26. One of the plugs 24--24 is inserted into one of the
jacks 26--26 assembled to the handset end and the other plug of the
retractile cord 23 inserted into a jack in the base of the
telephone 20. The plug 24 has facilities for establishing
electrical connections between the cord 23 and internal contacting
components 27--27 of the telephone 20 (see FIG. 10). Ones of the
plugs 24--24 are also assembled to each end of a line cord,
designated generally by the numeral 28 (see FIG. 1), for connecting
the line cord to jacks 26--26 in the telephone base and in a wall
terminal block 29.
Referring now to FIG. 5, a more detailed view of the structure of
the retractile cord 23 can be seen. The retractile cord 23 includes
a jacket 31 covering a plurality of insulated conductors 32--32. A
free end portion of each of the conductors 32--32 is designed to be
connected to an associated one of a plurality of terminals,
designated generally by the numerals 33--33. Each of the conductors
32--32 is constructed of a nylon core 34 having a tinsel ribbon 36
wrapped helically thereabout. The tinsel ribbon 36 has a nylon
insulation covering 37 extruded thereabout with a ridge 38 formed
longitudinally thereof. The outside nominal diameter of the
individual insulated conductors 32--32 is approximately 0.037
inch.
Miniature plugs constructed in accordance with the present
inventions permit the expeditious connection of cord ends to the
completed dielectric portion of the plugs rather than to a
dielectric subassembly which must then be assembled to at least one
other subassembly. This avoids having to maintain the cord 23 in a
predetermined position in the subassembly while assembling the
dielectric portion of the plug.
2. Dielectric Portion
The detailed construction of a plug 24 is shown in FIGS. 2, 4 and
7. A rigid, dielectric unpartite housing, designated generally by
the numeral 40, is designed to be easily molded by using
conventional injection molding techniques. The rigid, dielectric
housing 40 has a free end 41, a cord-input end 42, and a
terminal-receiving side 43 (see FIG. 4).
It may be observed from FIGS. 4 and 5 that the housing 40 is formed
with a cord input aperture 44 which circumscribes substantially the
portion of the jacket 31 of the cord 23 extending therethrough. As
may be appreciated from the drawing, the housing 40 is constructed
in one-piece with the cord input aperture 44 formed entirely
therewithin. The aperture 44 has a flared entrance which prevents
sharp bends in the cord 23 about an otherwise sharp edge during use
of the telephone 10 by the subscriber. This advantageously
increases the life of the cord 23. The flared entrance also
facilitates insertion of a leading end of the cord 23.
The cord input aperture 44 opens to a cavity 46 (see FIG. 4) which
partially terminates in a ledge 47 at the free end 41 of the base
of the housing 40. The cavity 46 substantially encloses the entire
end section of the cord which is inserted into the aperture 44 and
is completely formed as molded. No further securing together of
parts such as by bonding or moving of hinged parts with subsequent
bonding together is required to form the cavity 46.
The formation of a one-piece housing 40 with the surfaces defining
the cavity 46 substantially enclosing the entire end portion of the
cord 23 facilitates holding the cord while other operations are
performed by automated equipment. In prior art connectors, the cord
23 is generally positioned in a portion of a conductor-access
opening formed in a base and then a lid bonded to the base. This,
of course, will not suffice to hold the cord 23 in the base during
assembly without additional steps and equipment. Moreover, problems
have been experienced in consistently obtaining reliable bonds
between the cover and the base.
As can best be seen in FIGS. 2 and 7, the cavity 46 is formed with
a plurality of longitudinally extending partitions 48--48 which are
molded with the dielectric housing 40. The partitions 48--48 are in
the form of toothed ridges with a plurality of conductor-receiving
troughs 49--49 formed therebetween on 0.040 inch centers and
opening to the free end 41. The conductor-receiving troughs 49--49
are designed to receive associated ones of the conductors 32--32
(see FIG. 7). Each of the troughs 49--49 is dimensioned so that the
conductor 32 therein cannot move laterally. This is necessary to
insure that during the insertion of the terminals 33--33, the
terminals remain aligned with the conductors 32--32 to make
electrical engagement therewith.
It may be observed from FIG. 2 that the bottoms of the troughs
49--49 are substantially coplanar with the top surface of the ledge
47 at the free end 41. This facilitates the use of the ledge 47 at
the free end 41 as an anvil for conductor cut-off during assembly
of the plug 24 to the cord 23.
As can best be seen in FIG. 4, the portion of the cavity 46
adjacent the cord-input end 42 communicates with the main portions
of the conductor-receiving troughs 49--49 through a tapered
transition section 51 having a shoulder 52. The partitions 48--48
are constructed to extend along a sloping face 53 of the tapered
transition section 51.
After the jacket 31 of the cord 23 is stripped therefrom to expose
a predetermined length of each of the insulated conductors 32--32,
the cord is inserted into the input aperture 44 until the
conductors 32--32 are moved along associated ones of the
conductor-receiving troughs 49--49 extending down the sloping face
53. The portions of the partitions extending down the sloping face
53 assist in guiding the conductors 32--32 into the main portions
of the troughs 49--49. As the conductors 32--32 are moved up the
face 53, the jacketed portion of the cord 23 is being moved into
the cavity 46. When the cord 23 has been advanced such that the
conductors 32--32 are received in the troughs 49--49, the leading
end of the jacket 31 is in engagement with the shoulder 52 (see
FIG. 5).
Also, as can be seen in FIG. 4, the walls of the cavity 46 are
formed to include a groove 56 longitudinally thereof. The groove 56
is designed to mate with the ridge 38 formed externally of the
jacket to insure that the cord 23 is inserted properly into the
plug 24.
The housing 40 is also constructed with facilities for providing
strain relief for the jacket and for the individual conductors
32--32. This is one of the key features of the invention in that it
permits the use of a one-piece molded plug rather than two parts
assembled to the cord 23. As can best be seen in FIG. 4, the
housing 40 is constructed with an opening 59 having a
jacket-anchoring member 61 connected to a rear section of the plug
through a plastic hinge 62. Referring now to FIG. 2, it is seen
that the member 61 extends for only a portion of the width of the
housing 40. Moreover, the member 61 is connected at a forward end
thereof by a very thin tapered web of dielectric material 63.
The configuration of the connecting web 63 is very important. As
can best be seen in FIG. 4, the web 63 is constructed such that the
dimension "d.sub.1," adjacent a forward wall 64 is substantially
less than the dimension "d.sub.2 " adjacent the main body of the
member 61. This has two functions. It insures that the web 63 is
broken along the shearing plane along the dimension d.sub.1. The
shearing plane is a vertical plane adjacent the wall 64 along the
thinnest portion of the web 63. Secondly, the web 63 forms a
rounded trailing edge (see FIG. 5) of the hinged member 61 to be
formed and wrapped in a clockwise direction, as viewed in FIG. 5,
of the cord 23. In this way, there are no sharp burrs or edges to
tear the material comprising the jacket 31. Rather, the trailing
end of the web 63 curls around, as seen in FIG. 5, with the contour
of the cord 23.
The wrap-around effect of the web 63 permits the development of a
more effective resistance of the cord 23 to forces imparted to the
cord during customer use. If the member 61 were simply hinged
initially without the web 63 and moved pivotally to engage the cord
23, the member would bite into the jacket 31. Then, during use,
forces imparted to the cord 23 could cause a cutting of the jacket
31. However, the use of the web 63 which connects the member 61
initially to the portion 64 and then is severed, forms a blunt
portion which engages the jacket 31 and avoids cutting into the
jacket. This permits greater forces to be applied to the cord 23
without damaging the jacket 31.
The unitary dielectric housing 40 is also formed with facilities to
provide strain relief for the conductors 32-32. An opening 66
extends transversely across a portion of the housing 40 (see FIG.
2). As can be seen in FIG. 4, a conductor-anchoring member in the
form of a restraining bar 67 of dielectric material spans the
opening 66. A portion of the conductor restraining bar 67 is spaced
from the main portion of the housing 40 by slots 68 and 69 (see
FIGS. 4 and 8). The restraining bar 67 is integral with the walls
of the opening 66 through connecting portions 71 and 72. As can be
seen in FIG. 2, the ends of the restraining bar 67 of dielectric
material are spaced from the end walls of the opening 66.
In this way, an operator may cause a specially adapted tool 103
(see FIG. 8) to reform the restraining bar 67 within the opening 66
to provide a generally wedge-shaped strain relief element 70 (see
FIGS. 5 and 9) in engagement with ones of the individual conductors
32--32. Forces are applied to the restraining bar 67 to shear the
bar along irregular planes. The resultant strain relief element 70
is of a generally trapezoidal cross-section with the larger
dimension base in engagement with the conductors 32--32. The
sloping walls of the element 70 engage with the walls of the
opening 66 to lock the element in engagement with the conductors
32--32.
While the embodiment shown in FIGS. 4 and 8, shows the pressure bar
67 separated from the housing 40 by he slots 68 and 69, it should
be understood that other structural arrangements will suffice. For
example, one of the slots 68 or 69, desirably the slot 69, may be
extended to communicate with the cavity 46. Also, the restraining
bar 67 may be molded so that forces applied thereto cause the bar
to be moved linearly or pivotally to engage the conductors
32--32.
The use of the one-piece or unipartite dielectric housing 40
affords certain advantages. It permits an operator to simply insert
a jacketed cord 23. Heretofore, separate or hinged portions (see
application Ser. No. 311,575 filed Dec. 4, 1972 in the name of E.
C. Hardesty) are mated together to secure the cord jacket and the
conductors 32--32 within the assembled dielectric body. Finally,
the terminals 33--33 are inserted into the assembled dielectric
body.
In using a connecting device embodying the principles of this
invention, there is no required bonding of mating portions with
accompanying problems of alignment and reliability of the bond.
Moreover, the housing 40 has provisions molded therewith for
securing the cord 23 to the plug and for alleviating strain relief
on the cord jacket 28 and the conductors 32--32 during customer
use. The jacket-anchoring member 61 and the conductor restraining
bar 67 not only secure the plug 24 to the cord 23 but also provide
strain relief for the jacket and the conductors, respectively.
After the cord 23 has been inserted into the aperture 44 and
operator may apply forces to the member 61 to break the connection
63 and move the resulting tooth portion thereof into engagement
with the cord jacket 31. As this is done, an upper portion 65 of
the hinged member 61 catches under a ledge 73 (see FIGS. 5 and 9)
which has been formed upon breaking the web 63. The strain relief
for the individual conductors 32--32 is provided by reforming the
dielectric restraining bar 67 downwardly within the opening 66 into
the strain relief element 70 which engages with the individual
conductors 32--32.
In this way, the terminals 33--33 function only to make electrical
contact with the conductors 32--32 and are not required to retain
the conductors and resist the forces imparted to the conductors or
the cord during customer use. The forces on the conductors 32--32
occur notwithstanding the anchoring of the jacket 31 with the
member 61. While the pressure on the jacket 31 may prevent the
insulation 37 of the conductors 32--32 from moving relative to the
jacket, the pressure is not sufficient to prevent the nylon core 34
and ribbon 36 from moving relative to the insulation thereof during
customer use. This occurs because the relatively hard nylon
insulation 37 forms what may be thought of as a tubulation over the
core 34 and nylon 36 wrapped about the core. Forces applied to the
cord 23 by the subscriber tends to cause the core 34 and ribbon to
move slideably within the insulation 37. This movement, if
unchecked, could cause the tinsel ribbon to be sheared off the core
34 at the engagement thereof with portions of the terminals
33--33.
The molding of the housing 40 with the ability to be able to
precisely confine the conductors 32--32 in the troughs 49--49 is
especially important. Prohibition against movement is necessary in
order to cause the terminals 33--33 to penetrate the
nylon-insulated conductors 32--32. The terminals 33--33 must be
inserted with sufficiently high forces imparted thereto to
penetrate the insulation. If the conductors 32--32 were free to
move laterally of the plug, the terminals 33--33 may very well
slice into the insulation on either side of the conductive elements
and fail to establish engagement therewith.
As can best be seen in FIG. 2, the housing 40 is formed with a well
74 having a plurality of spaced parallel terminal-receiving
openings 76--76 opening thereto. The openings 76--76 are in the
form of slots and are aligned on a one-to-one basis with associated
ones of the conductor-receiving troughs 49--49. Each of the
terminal-receiving slots 76--76 is parallel to and communicates
with an associated one of the conductor-receiving troughs 49--49.
Each of the slots 76--76 is of a length slightly less than the
out-to-out distance of that portion of the terminal 33 which is to
be received therein. The shortening of the slots 76--76 from the
overall length of the well 74 forms abutments 77--77 (see FIG. 4,
for example).
The dielectric housing 40 is also formed with a plurality of fins
78--78 (see FIGS. 2, 3 and 7). The fins 78--78 are upstanding from
a bottom surface 79 of the well 74 to which the terminal-receiving
slots 76--76 open and are spaced apart approximately 0.035 inch.
Also, the fins 78--78 are aligned between adjacent associated ones
of the terminal-receiving slots 76--76. In this way, the external
contacting components 27--27 of the jack 26 are received between
the associated fins 78--78 and guided into engagement with portions
of the terminals 33--33.
Formed integrally with the dielectric housing 40 is a resilient
locking tab, designated generally by the numeral 80. The locking
tab is approximately 0.040 inch thick, 0.200 inch wide, and 0.500
inch long. The locking tab 80 is molded so that its longitudinal
axis is oriented at an angle approximately 15.degree. with respect
to the plane of the terminal-inserting side 43. The locking tab 80
is molded with a generally flat portion 81 connected by a plastic
hinge 82 to the free end of the housing. The portion 81 is stepped
to form wings 83--83 adjacent a subscriber-contact portion 84.
The combined height of the thickness of the locking tab 80 and
resiliency of the locking tab permits the insertion of the plug 24
into the jack 26 between opposing surfaces 85 and 86 (see FIG. 10).
The tab 80 can be deflected inwardly of the dielectric housing 40
to become substantially coplanar with the under-surface of the
housing 40 and be moved slideably in engagement with the surface 85
which forms an entrance ledge (see FIG. 10).
After being released, the locking tab 80 will essentially resume
its original molded shape and orientation because of its natural
resilience. Proper resilience to provide desired flexing properties
can be incorporated into the locking tab 80 when it is molded from
polycarbonate or other appropriate materials with the
aforementioned dimensions. Return of the tab 80 to its originally
molded shape causes the free end of the tab to be urged downwardly
into seating engagement with surfaces of the jack 26 (see FIGS. 10
and 11) in the handset 22 and base 21. A wall 87 and the ledge
surface 85 cooperate to form an edge 88 which engages the locking
tab 80. This locks the plug 24 to the jack 26 in the handset 22 and
insures integrity of the connection during customer use.
The locking tab 80 is designed to permit the plug 24 to be released
from the handset 22 when subjected to at least a predetermined
force rather than to break the plug or rupture the cord 23. In
order to accomplish this, the tab 80 is constructed with shallow
angled shoulders 89--89 (see FIGS. 2 and 3) which form the wings
83--83. When the plug 24 has been inserted into the jack 26, the
shoulders 89--89 engage the edge 88. The shoulders 89--89 ride up
along the edge 88 when forces of a predetermined magnitude are
imparted to the cord 23. Continued application of the forces cause
withdrawal of the plug 24 from the jack 26.
3. Terminals
As can best be seen in FIG. 2, each one of the terminals 33--33 is
made from an electrically conductive resilient material such as
Phosphor bronze. The terminal 33 has a flat conductive portion 91
with at least one contact or insulation-piercing tang 92 protruding
therefrom. The tangs 92--92 provide electrical connection between
the conductive portion of the conductor 32--32 and the associated
ones of the terminals 33--33.
Each of the blade-like terminals 33--33 also has an edge surface 93
having curved crowns 94--94 of predetermined radii. The crown 94
nearest the free end 41 of the housing 40 functions to complete the
connection between the associated conductor 32 and an associated
external-contacting component 27 illustrated in FIG. 10, and
positioned in the telephone jack 26.
Provisions are also made for seating properly the terminals 33--33
within the associated terminal-receiving slots 76--76. Each of the
terminals 33--33 is formed with shoulders 96--96 having necked-down
portions 97--97 that terminate in barbs 98--98. As was indicated
hereinbefore, the overall length of the terminal 33 out-to-out of
the barbs 98--98 is greater than that of the length of the
terminal-receiving slot 76. When the terminal 33 is inserted into
the associated terminal-receiving slot 76, the barbs 98--98
penetrate the dielectric material which defines the slot to anchor
the terminal (see FIG. 5).
The extent to which the terminal 33 is inserted into the associated
slot 76 is determined by the operation of an apparatus, designated
generally by the numeral 100 (see FIG. 12) used to insert the
terminals. Generally, the apparatus 100 is controlled to insert the
terminals 33--33 within the associated ones of the
terminal-receiving slots 76--76 such that the shoulders 96--96 are
spaced above the abutments 77--77.
The extent to which the terminal 33 is inserted into the associated
terminal-receiving slot 76 is controlled to also insure that
adequate electrical engagement is effected between the terminal
tangs 92--92 and the conductors 32--32. If the depth of insertion
is lacking, the tangs 92--92 may not engage one or both aligned
portions of the helical tinsel ribbon 36. On the other hand if the
depth of insertion is too great, the shoulders 98--98 could rupture
the abutments 77--77. It is important that the tangs 92--92 engage
the top or closest portion of the tinsel ribbon 36, be moved
through the core 34, and into engagement with the bottom portion of
the helically wrapped tinsel ribbon.
While the terminals 33--33 have been shown in a flat blade-like
configuration, it should be obvious that they could be in the form
of pins (not shown). Of course, the terminal-receiving openings
76--76 would then be molded to accommodate the pins (not shown)
rather than the blade-like terminals 33--33.
ALTERNATE EMBODIMENT OF DIELECTRIC PORTION
There have been instances of contaminants and corrosive atmospheres
penetrating the plug 74. This could cause problems in maintaining
electrical continuity and reduction in the effectiveness of the
electrical engagement between the terminals 33--33 and the cord
23.
In order to prevent such occurrences, the housing 40 of the plug
may be modified to that designated 40A and shown in FIG. 6. The
housing 40A is identical to the housing 40 except that the free end
41 has a wall 99 closing off the conductor-receiving troughs
49--49. This prevents any contaminants or unwanted atmospheric
corrosives from entering the plug 24 at least from the one end
thereof adjacent the terminals 33--33. This creates an essentially
hemetic seal.
In using the plug 24 having a modified housing 40A, the cord 23
must be stripped of the jacket 31 with some precision to expose
only a predetermined length of the conductors 32-32. Then, when the
cord 23 is inserted into the cavity 46 and the free end of the
jacket 31 abuts the shoulder 52, the ends of the conductors 32-32
will be spaced slightly from the wall 99.
SECOND ALTERNATE EMBODIMENT OF DIELECTRIC PORTION
It will be recalled that the embodiment first described herein
discloses that the cord 23 have the jacket 31 removed from a
leading portion thereof to expose the individual insulated
conductors 32--32. The individual conductors 32--32 are received in
the conductor-receiving troughs 49--49.
The principles of this invention may be used to construct a housing
40 which may accommodate an end portion of a flat cord 23 without
the necessity of removing the jacket from an end portion thereof.
The cavity 46 is molded without the conductor-receiving troughs
49--49 and such that a leading end portion of the cord 23 is
inserted into the cavity. The cavity 46 is constructed to
communicate with the terminal-receiving slots 76--76 and may or may
not open to the free end 41 of the housing 40 (see FIG. 6).
In using this embodiment, the end portion of the cord 23 is
inserted into the cavity 46. Then the terminals 33--33 are driven
into the slots 76-76 into engagement with the conductive elements
of the cord 23. Since the cord 23 is flat, and assuming that the
cord is inserted properly into the cavity 46, the conductive
elements of the cord are aligned properly with the terminals
33--33.
METHOD OF ASSEMBLING PLUG WITH CORD
The construction of the plug 24 is especially adapted to be used
with flat cordage. Moreover, the plug 24 is easily adapted to
automated high speed manufacturing. In describing the assembly of
the plug 24 and the cord 23, reference will be made to FIGS. 4 and
5 which depict the steps of the method. Reference will also be made
to FIG. 12 which illustrates the apparatus 100. The apparatus 100
is exemplary of apparatus which may be used to carry out the steps
of the method.
One of the plugs 24--24 is positioned in a work holder 101. Then a
leading end of the jacketed cord 23 has a portion of the jacket 31
stripped therefrom. The leading end of the cord 23 is inserted into
the flared entrance 44 and into the cavity 46 with the conductors
riding up along the sloped portion 53 until the conductors 32--32
are received in associated ones of the conductor-receiving troughs
49--49. At that time, the leading edge of the jacketed portion 31
engages the shoulder 52. Also, then, the conductors 32--32 extend
onto and perhaps slightly past the ledge 47.
An advantage of constructing a one-piece dielectric housing 40
derives from the alignment feature of the cord 23 with the housing.
In using prior plugs, it was necessary to align the conductors
32--32 with appropriate conductor-receiving facilities within the
plug and to maintain that alignment during the insertion of the
terminals 33--33. This is unnecessary in using the plug 24
embodying the features of this invention since the insertion of the
cord 23 within the plug automatically maintains the cord
therewithin and aligns the individual conductors 32--32 with the
associated ones of the troughs 49--49.
There is still another significant advantage realized from the use
of the one-piece plug 24. The dimensions of the separate dielectric
portions in a two-piece plug may vary within tolerances as between
different molding tools. This may cause problems of alignment as
between successive matings of successive pairs of parts and further
may cause problems of alignment of the terminals 33--33 and
associated conductors 32--32 in assembly equipment when using parts
from different molds. With the one-piece plug 24, the
terminal-receiving slots 76--76 are inherently aligned with the
conductor-receiving troughs 49--49.
Because the cord 23 is flat and because of the assembly process,
the conductors 32--32 are spaced in a prearranged order in the
troughs 49--49. Once the cord 23 is inserted into the housing 40 in
the correct orientation, then it is unnecessary for an operator to
identify the conductors 32--32 prior to the electrical connection
with ones of the terminals 33--33. The order in the cord 13 is
maintained in the plug 24 to correspond to the order of engagement
with the external contact elements 27--27.
However, to insure the correct orientation of the cord 23 with
respect to the plug 24, the cord must be inserted into the plug in
such a fashion to insure that the order of the conductors 32--32 is
correct. Since the cavity 46 is formed with the groove 56, the cord
23 should be inserted such that the ridge 38 on the cord jacket 31
is received in the groove. If the cord 23 were inserted in an
inverted position, the conductors 32--32 would not be oriented
properly with the terminals 33--33 and hence with the external
contacting components 27--27. Also, the subsequent engagement of
the member 61 with the cord 23 would span the ridge and not be
fully seated across the jacket enclosing the four conductors
32--32. This would result in a less efficient anchoring of the
jacket 31.
The operator then causes a tool 102 to be moved into engagement
with the member 61 to break the thin web 63. The now-hinged member
61 is moved counterclockwise, as viewed in FIG. 5, until the
toothed portion 65 thereof catches and locks under the newly formed
ledge 73. As can be seen in FIGS. 5 and 9 the thin web 63 is such
that the free end thereof curls around to form a blunt portion
which engages the cord jacket 31.
Next, the operator causes the tool 103 to engage the
conductor-restraining bar 67 within the opening 66 (see FIG. 8) and
apply compressive forces thereto. The conductor bar 67 is reformed
and broken off along the lines shown dotted in FIG. 9 into the
tapered or wedge-shaped dielectric element 70 (see FIG. 9) and
moved into engagement with the conductors 32--32. The element 70
spans the conductors 32--32 with the bottom portion thereof tending
to assume the partial peripheral shape along the tops of the
conductors 32--32. Moreover, the element 70 is locked in the
position shown in FIG. 9. The element 70 therefore locks the
conductors in the troughs 49-49 to provide strain relief for the
conductors while the toothed portion of the hinged member 61, i.e.,
the web 63, provides strain relief for the jacket 31.
The tool 103 used to reform the body 67 spans the entire opening
66. This is unlike the tool 102 which is used to move the member
61. In this way, downward movement of the tool 103 does not cause
the restraining bar 67 to be moved pivotally about one of the
connecting portions 71 and 72. Rather, as shown in FIG. 9, the
restraining bar 67 is moved downwardly beginning at the bottom of
the slots 68 and 69 and mushrooms outwardly. This in effect forms
the strain relief element 70 having a generally trapezoidal
cross-section which is locked at the bottom of the opening 66 in
tight engagement with the conductors 32--32.
Then the free end portions of the conductor 32--32 are trimmed off
with a cutting device 104 using the ledge 47 as a bearing surface.
The extension of the leading ends of the conductors 32--32 onto the
ledge 47 avoids having to strip exactly the leading ends of the
conductors.
In the alternative embodiment shown in FIG. 6 with the troughs
49--49 not opening to the ledge 47, the conductors 32--32 are
presized to approach the ends of the troughs. The cut-off must be
such that the conductors extend beyond the most forward one of the
tangs 92--92. The construction of the plug 24 with a closed front
end minimizes moisture absorption and exposure of the terminals
33--33 to a corrosive atmosphere. This creates an effective hemetic
seal.
In order to complete the assembly of the plug 24 to an end of the
cord 23, four of the terminals 33--33 are inserted into the plug.
The blade-like terminals 33--33 are inserted by rams 106--106 from
the terminal-receiving face 43 of the plug 24 into associated ones
of the terminal-receiving slots 76--76 until the rams bottom out.
The shoulders 96-96 thereof are spaced above the abutments 77--77
(see FIG. 5). At that time, the contact tangs 92--92 extend into
the associated trough 49--49. The tangs 92--92 penetrate the
insulation of the conductors 32--32 confined in the troughs 49-49
and establish electrical contact with both the upper and lower
wraps, as viewed in FIG. 5, of the tinsel ribbon 36. Also, the
barbs 93--98 are caused to become embedded in the portion of the
dielectric housing 40 which defines the terminal-receiving slot
76--76. This anchors the terminal 33--33 against movement or
inadvertent removal from the housing 40.
An apparatus for completing the formation of and inserting the
terminals 33--33 into housing 40 is disclosed and claimed in
application Ser. No. 346,556 filed on Mar. 30, 1973 in the names of
W. B. Brown (deceased) and F. D. Gavin.
Of course, apparatus other than the apparatus 100 may be used to
practice the methods of this invention. For example the assembly of
the plug 24 to the cord 23 could be accomplished by using a
turntable, (not shown) with facilities for inserting the cord,
stripping the cord, etc. arranged about the periphery of the
turntable. Successive cords 23--23 and associated plugs 24--24 are
moved with the turntable (not shown) through the work stations.
It is to be understood that the above described arrangements are
simply illustrative of the invention. Other arrangements may be
devised by those skilled in the art which will embody the
principles of the invention and fall within the spirit and scope
thereof.
* * * * *