U.S. patent number 3,743,087 [Application Number 05/062,697] was granted by the patent office on 1973-07-03 for cold formed plastic connector housing.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to Joseph Agusta Wise.
United States Patent |
3,743,087 |
Wise |
July 3, 1973 |
COLD FORMED PLASTIC CONNECTOR HOUSING
Abstract
A method and means is disclosed featuring a cold forming of
plastic bodies in the form of buttons, pellets or other simple
shapes into more complex functional configurations for housing and
insulating electrical terminals, mechanical fasteners and the like.
The plastic bodies are integrally joined to a thin flexible carrier
to facilitate processing. Cold forming is effected by dies brought
to bear against the bodies with one of the dies carrying a
connector element which forms part of the working die surface. The
final forming of the housing deposits or embeds the connector
element within plastic material. By making the initial molded
configuration of a body topographically similar to the final
configuration to reduce the extent of extrusion along a given axis
the resulting housing may be made to better withstand subsequent
deformation for crimping purposes to terminate electrical leads
within the terminal and housing or mechanically fasten other
elements together.
Inventors: |
Wise; Joseph Agusta
(Mechanicsburg, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
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Family
ID: |
26742581 |
Appl.
No.: |
05/062,697 |
Filed: |
August 10, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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742427 |
Jul 3, 1968 |
3606000 |
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800682 |
Feb 19, 1969 |
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Current U.S.
Class: |
206/717;
174/87 |
Current CPC
Class: |
B29C
51/12 (20130101); B29C 63/00 (20130101); B29C
67/0029 (20130101) |
Current International
Class: |
B29C
51/00 (20060101); B29C 51/12 (20060101); B29C
67/00 (20060101); B29C 63/00 (20060101); B65d
073/02 (); H01r 005/10 () |
Field of
Search: |
;206/56A,56AB,65F
;174/87 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Summer; Leonard
Parent Case Text
RELATED CASES
This case is a continuation-in-part of Ser. No. 742,427 filed July
3, 1968, and now U.S. Pat. No. 3,606,000, in the name of Joseph
Agusta Wise and entitled THERMOFORMED PLASTIC COVERED CONNECTORS,
and a continuation of Ser. No. 800,682 filed Feb. 19, 1969 and
entitled COLD FORMED PLASTIC CONNECTOR HOUSING and now of course
abandoned.
Claims
I claim:
1. As an article of manufacture, a thin web of flexible and
reelable material carrying a series of discrete electrical
connector assemblies thereon, each assembly comprising a generally
tubular plastic housing projecting from one surface of said web and
being closed at the end thereof remote from said web, and a
metallic sleeve having an outwardly extending flange on one end
being snugly encased about its entire outer peripheral wall portion
in the housing in the closed end thereof with said flange being
embedded in the plastic material of the housing, the thickness of
the web being less than the radial thickness of the wall of the
housing.
2. An article according to claim 1 in which the materials of the
sleeves and housings are of inelastically deformable material for
crimping the sleeve into engagement with conductors adapted to be
inserted in said sleeve.
3. An electrical connector according to claim 2 in which the
housings and web are of the same material with the open end of each
of the housings being integral with the web.
Description
BACKGROUND OF THE INVENTION
Many types of electrical and mechanical connectors are comprised of
a plastic insulating housing containing within at least a portion
thereof a metal sleeve adapted to receive elements such as a wire
or wires to be permanently joined by deformation of the sleeve
through forces applied to the housing. One widely used device of
such construction has a conically shaped plastic housing with a
sleeve of metal contained in one end and with the other end open to
receive the stripped ends of two or three wires which are then
terminated together by a deformation of the sleeve of metal through
forces applied to the plastic. U. S. Pat. No. 2,823,250 to M. F.
O'Keefe discloses an example of the foregoing.
By and large, with respect to connectors of the foregoing type,
present-day manufacturing practice calls for a molding of the
connector housing followed by insertion of the metal sleeve as a
separate step. The housings are typically injection molded using
molds containing 10, 20, 30 or more housing cavities; the large
number being necessary for economy. Complex multicavity molds are
expensive to build, to maintain and numerous problems attend
production use caused by the required network of sprues, ventholes,
and the like, leading to and from the cavities. A substantial
amount of plastic scrap may be expected. Furthermore, since the
plastic must be injected under relatively precise temperatures and
pressures and caused to flow without sticking throughout the mold
surfaces, set-up and close-down times are relatively long.
As an additional point, for high production usage, it is frequently
desirable to place the loosepiece parts produced by injection
molding on some form of carrier such as a tape capable of being
utilized in an automatic machine. This adds to the cost of the
product and substantially limits its utility.
SUMMARY OF THE INVENTION
The present invention relates to a method and means for cold
forming plastic into housings for electrical terminals, connectors,
mechanical fasteners and the like.
It is an object of the present invention to provide a method for
forming housings for electrical terminals, connectors and
mechanical fasteners in a manner which is less expensive than
heretofore available. It is another object to provide a method for
forming plastic housings through the use of dies and cold working
plastic material. It is yet another object to provide a method of
cold working plastic material into a series of housings mounted on
an integral carrier which may be utilized to advantage for
inventory, transportation, and final installation by automatic
equipment. It is still another object of the invention to provide
an assembly of plastic and connector elements utilizing the
connector element in conjunction with other die surfaces to form
the plastic element into a housing for such assembly. It is a
further object to provide a cold formed, multipart, preinsulated
electrical terminal, connector or mechanical fastener.
The foregoing objects are attained by the invention through the use
of dies, closed together against plastic bodies of a simple
configuration into a more complex configuration defining housings
without the usual application of temperature and/or pressure
employed in injection molding or extrusion of a molten plastic base
material. The web containing plastic bodies is pre-molded or
otherwise formed in a strip to facilitate automatic manufacturing
techniques much like a metal stamping operation. The finished
housings formed on the web are in a preferred embodiment left
joined thereto with the web then being used as a carrier for
processing. In one embodiment metal sleeve elements are positioned
on one of the pair of mating die surfaces to serve as part of the
plastic working surface during cold extrusion with the sleeve being
embedded to be left within the housing upon die separation. In a
preferred embodiment of a terminal adapted to be crimped onto the
ends of the wires the plastic body is given an initial shape which
has been better found to withstand crimping forces applied thereto
to deform the metal sleeve contained therewithin.
In the drawings:
FIG. 1 is a perspective view showing the invention method and means
with a plastic web containing plastic bodies being fed from left to
right past a die station; the dies being shown separated and the
upper die being shown in partial section;
FIG. 2 is a side and elevational view showing a preferred body
configuration;
FIGS. 3A, 3B, and 3C, show initial, intermediary and final
positions of working dies, respectively, the upper dies being shown
in partial section; and
FIG. 4 is a perspective view of a terminated electrical
connector.
DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION
Referring now to FIG. 1, a source of thermoplastic material 10 is
shown being fed from the left toward and through a die station
comprised of a pair of movable dies 20 and 32, supported and driven
for reciprocating movement along the axis indicated by the arrows.
The material 10 is comprised of a web 11 carrying discrete
cylindrical bodies 12 suitably spaced to facilitate working of the
metal. Each body 12 has a circular recess 13 in the bottom, as
shown in FIG. 3A. The means for mounting and moving the material 10
and the dies 20 and 32 is not shown, but may be understood to be
similar to means employed in the metal stamping arts, in terms of
drive, displacement and feed. To the right of the tooling shown in
FIG. 1 are finished assemblies 16, each comprised of a plastic
housing 14 (formed from a body 12) containing a connector element
in the form of a metal sleeve 18 locked therein. As can be
discerned from FIG. 1, sleeves 18 are positioned on the lower die
20 prior to die closure and material forming.
The material forming operation is shown in FIGS. 3A, 3B and 3C. In
FIG. 3A a plastic body 12 is shown positioned beneath the cavity 36
of upper die 32 with the lower die 20 moved to engage a lower
recessed surface 13 of the body 12. The recess 13 serves to relieve
the web from the forces applied to deform 12. The V-shaped section
shown in phantom in FIG. 3A relates to an alternative plastic body
configuration as depicted in FIG. 2, which will be discussed in
greater detail hereinafter. As can be seen from FIG. 3A, lower die
20 includes a generally cylindrical base portion 22 carrying a
conical portion 24, which in turn carries a cylindrical portion 26.
Extending from 26 is a cylindrical portion 30 of a diameter to
receive sleeve 18, leaving a portion of 30 extending above the end
of the sleeve. Sleeve 18 rests upon a step 28 which is the upper
surface of 26. The dimensions of 30 relative to the dimensions of
18 are such that 18 is slidingly fitted thereon. Die cavity 36 has
a complementary shape relative to the configuration of die element
20 while carrying a member 18 to define a desired housing shape.
FIG. 3B shows die 20 moved upwardly relative to 32 to cause a
forming of body 12 by an extrusion and working of the material
thereof up into the cavity 36 and down against the surface of
sleeve 18 and the upper portion of 30. FIG. 3C shows a completed
closure of die 20 into cavity 36 with the material of 12 now worked
into a final configuration forming a housing H of a connector
assembly 16. As can be discerned from FIG. 3C, the material of 14
(12) is formed in around the lower edge portion of 18, such portion
being shown as 19 in FIG. 3C. This serves to lock the sleeve within
the housing. As can also be discerned from FIG. 3C, web 11 is left
intact to form a strip. Web 11, as also shown left intact in FIG.
1, may be utilized as a carrier; not only for production purposes,
but for storage, inventory, transportation and utilization in
automatic equipment, as in an automatic terminal crimping machine.
The strip carrying assemblies 16 may be reeled in some suitable
fashion permitting large numbers of connectors to be carried in a
relatively small space. The invention also contemplates that the
carrier may be wider than that shown to position arrays of bodies
in parallel for use with sets of die pairs mounted in parallel.
I have discovered that many plastic housing configurations of types
previously formed by injection molding techniques may be
essentially cold formed from a simple body or block of plastic
directly in stamping dies to a high degree of accuracy while still
maintaining characteristics in the plastic material adequate to
achieve the function required for electrical connectors and
mechanical fasteners. In an actual sample like that shown in FIGS.
1 and 3A-3C, the body 12 was approximately 0.425 of an inch in
diameter and 0.210 of an inch high and was formed of Zytel No.
1.01, a readily available nylon product of E. I. Dupont deNemours
Company Incorporated. In such actual embodiment the body 12 was
initially molded along with web 11 of the same material
approximately 0.010 of an inch in thickness and 0.625 of an inch in
width. Based upon my experience with this thermoplastic material,
other thermoplastic materials, including those in the polyolefin
family, could be similarly worked. Cold forming by dies of the
configuration shown was tried at relatively high rates (with a
press running at 300 strokes per minute) or at very slow rates of
forming (the flywheel of the die press being rotated manually
through a cycle).
For terminals, connectors or fasteners which require deformation of
a metal structure contained within a plastic housing it has been
found preferable to utilize an original body shape which can be
formed with minimum material working along the axis of material
displaced by deformation. With respect to the assembly housing 16
heretofore discussed a preferred original body configuration is
shown in FIG. 2. There a strip 40, includes a web 42 carrying a
series of bodies 44, which are generally conical in shape and
include an interior recess 46. Such recess reduces material working
and relieves the web 42 from forces working 44. FIG. 3A shows a
body 44 positioned between dies 20 and 32. By having the original
body of such configuration the plastic material is worked
considerably less along the lengthwise axis of dies 20 and 32 then
in the previous embodiment. As one result the plastic housing 16 is
left with appreciably greater strength and resistance to cracking
relative to crimping forces applied to the region of the housing
surrounding sleeve 18. The arrows in FIG. 4 show the axis of force
application used to crimp the connector. These forces are usually
applied by a tool which inelastically deforms the plastic and
sleeve 18 from a cylindrical configuration to a generally oval
configuration relative to a cross-section taken through sleeve 18
and the housing relative to the length axis of the assembly.
In the embodiment shown in FIG. 1, bodies 12 and thus the complete
assemblies 16 are joined by an integral web of plastic material 11.
The invention contemplates the placement of bulk plastic bodies to
form housings in series on a plastic web or carrier which is
integral in the sense of being molded with the bodies or joined
thereto by an adhesive or by plastic welding or the like. If a web
having discrete plastic bodies joined thereto is used apertures in
the web may be provided aligned with recesses like 13 and 46 to
prevent the web from being torn by the dies in working the bulk
material. The web may also be punched with slots if desired to
provide processing and field use.
While not shown, it is contemplated that the formed assemblies may
be severed from the web to be packaged in a loose-piece form if
desired.
The invention, as heretofore described relative to specific
connections, contemplates in one aspect the forming of plastic
housings into which elements are inserted to provide an operable
connector assembly. While metal sleeves have been disclosed as such
elements, metal springs, clips or even plastic members such as
nuts, washers and the like are contemplated. The invention also
contemplates that in certain applications the housings may be
formed prior to element insertion, the dies defining the final
shape of the housing and the element fitted and secured therein as
a separate step.
The invention as taught thus contemplates a carrier with simple
body shapes usable to provide a variety of different housing shapes
or a carrier with a specialized body shape usable for a specific
housing as alternatives dependent upon preference and application
requirements.
Having now disclosed my concept for a new method and means in terms
intended to enable a preferred practice thereof in its several
modes and embodiments, I define what is believed inventive through
the appended claims.
* * * * *