U.S. patent number 3,853,377 [Application Number 05/212,091] was granted by the patent office on 1974-12-10 for tight fitting plug connection and method for making same.
Invention is credited to Bernard Edward Shlesinger, Jr..
United States Patent |
3,853,377 |
Shlesinger, Jr. |
December 10, 1974 |
TIGHT FITTING PLUG CONNECTION AND METHOD FOR MAKING SAME
Abstract
A connector element for electrical devices and the like
comprising: a conductive sleeve having an expansible core receiving
portion including a wall; a core of elastic material under
compression received in the core receiving portion and exerting an
expansion force on the wall of the receiving portion when residing
therein; the sleeve being of a material harder than and
substantially less compressible than said core material. The sleeve
being normally expanded by the pressure of the material under
compression so that when mated with its cooperating connector
element, the sleeve will grip the cooperating connector element
affording positive connection and wipe at all times regardless of
the number of connects and disconnects made.
Inventors: |
Shlesinger, Jr.; Bernard Edward
(Alexandria, VA) |
Family
ID: |
26906764 |
Appl.
No.: |
05/212,091 |
Filed: |
December 27, 1971 |
Current U.S.
Class: |
439/593;
439/825 |
Current CPC
Class: |
H01R
13/15 (20130101) |
Current International
Class: |
H01R
13/15 (20060101); H01r 013/40 (); H05k
001/04 () |
Field of
Search: |
;339/17,18,59-63,176,191,192,193,194,195,196,198,278C,278D,182,252,74,30,94 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
IBM Technical Disclosure Bulletin, Vol. 13, No. 4, Sept. 1970,
"Expandable Pin for Circuit Board," Ecker et al. .
IBM Technical Disclosure Bulletin, Vol. 7, No. 9, 02-1965,
"Installing Charges on a Multilayer Board," Byrnes et al..
|
Primary Examiner: Gilliam; Paul R.
Assistant Examiner: Lewis; Terrell P.
Attorney, Agent or Firm: Shlesinger, Arkwright, Garvey &
Dinsmore
Claims
Having thus described my invention, what I claim is:
1. A removable, reusable electrical connector element for mating
connector components and the like comprising:
a. a conductor sheath having a substantially regularly shaped
surface and a resilient, compressible, flexible and expandable
spring wall portion
b. a core of resilient elastic material in contact with said
conductive sheath and at all times under compression and at all
times exerting a force on said spring wall portion
c. said spring wall portion being slightly and non-abruptly
deformed by said core material and at all times under stress
d. said sheath including means for permitting flexing of said
spring wall portion inwardly and outwardly, and
e. said sheath being substantially less compressible than said core
material.
2. A connector element as in claim 1 and wherein:
a. said core is comprised of resilient plastic material.
3. A connector element as in claim 2 and wherein:
a. said core plastic material is conductive.
4. A connector element as in claim 2 and wherein:
a. said sheath includes at least one slot extending parallel to the
longitudinal axis of said connector.
5. A connector element as in claim 2 and wherein:
a. said sheath includes at least two slots aligned and parallel to
the longitudinal axis of said connector.
6. A connector element as in claim 5 and wherein:
a. said sheath includes a series of slots spaced radially about the
axis of said sheath.
7. A connector element as in claim 1 and wherein:
a. said sheath is cylindrical in configuration.
8. A reusable electrical connector element for a mating connector
component and the like comprising:
a. a conductive member having a substantially regularly shaped
surface and a resilient, compressible, flexible, expandable spring
backing receiving portion
b. a backing of resilient, elastic material in contact with said
conductive member and at all times under compression and at all
times exerting a force on said spring backing receiving portion
c. said spring backing receiving portion being slightly and
non-abruptly deformed by said backing and at all times under
stress,
d. said conductive member including means for permitting flexing of
said spring backing receiving portion inwardly and outwardly
e. said conductive member being substantially less compressible
than said backing, and
f. stop means associated with said conductive member for limiting
the amount of closing of said backing receiving member.
9. A connector element as in claim 8 and wherein:
a. said conductive member is a sleeve.
10. A connector element as in claim 9 and wherein:
a. said backing supports a second sleeve mounted concentric with
said first mentioned sleeve.
11. A connector element as in claim 9 and wherein:
a. said stop means includes a split in said sleeve.
12. A connector element as in claim 11 and wherein:
a. said stop means includes the side edges of said split.
13. A connector element as in claim 9 and including:
a. a base member
b. an opening in said base member, and
c. said backing mounted in said opening.
Description
HISTORICAL BACKGROUND
Since most existing electrical connectors are made of metal having
poor spring tensile properties, they tend to wear out after
repeated insertion and withdrawal. This loss of resilency results
in a loosely secured plug and concomitant poor electrical
continuity.
Even the addition of springs to contribute to the resiliency of the
connector has not afforded a satisfactory solution. The use of
mechanical springs, due to the number of moving parts required,
greatly increase the cost of production. Additionally, they are not
practical for use in miniaturized connectors.
The present solution for this problem of providing a connector
having long life and adequate resiliency is known. Several attempts
at the solution are shown by Camzi, U.S. Pat. No. 3,031,641; Smith,
U.S. Pat. No. 2,502,634; and McFadden, U.S. Pat. No. 3,350,676.
With the development of new plastics having long life and adequate
elasticity, it has become possible to incorporate them into a
connector unit, thereby providing a natural spring system which is
inexpensive and simple to manufacture.
SUMMARY AND OBJECT
This invention relates to an electrical plug and/or receptacle
connector which is resiliently biased thereby maintaining a tight
connection between it and its mating part. The sheath of the plug
is expanded by the presence of compressed material enclosed
therein. The sheath is considerably less compressible than the core
material, but the presence of slots or thinned portions in the wall
permit the radial expansion and/or compression. The plug sheath
expands outwardly whereas the receptacle sheath expands inwardly.
The receptacle conductive contact member has a backing of elastic
material under compression which exerts an expansion force on the
conductive member forcing it against a plug inserted therein. In
this manner a rigid connector plug may be tightly gripped by the
resulting pressure created by the compressed backing material. Both
cooperating plug and receptacle may be expandable as taught by this
invention.
The connectors are made by introducing an elastic material under
pressure into a hollow expansion member and then sealing this
expansion member to retain the compressed material. A variation on
this process is to place the expansion member, which is slotted,
bifurcated or otherwise designed so that it may expand outwardly in
a die and then inject the pressurized elastic material, such as a
gas, fluid, liquid, plastic, or the like. In the case of plastic,
rubber, etc., when the elastic material has solidified, the die is
removed and the expansion member will be forced in an outward
direction.
It is an object of this invention to provide a plug connector of
great utility for use with printed circuit boards and prewired
modules.
It is a further object of this invention to provide a plug and
receptacle which, due to their inherent resiliency, will be
securely connected upon mating.
It is another object of this invention to provide a resilient
connector without the use of mechanical springs and the like which
lose resiliency and may eventually break under prolonged use.
It is a further object of this invention to provide a plug
connector which is simple in design and relatively free of moving
parts.
A still further object of this invention is to provide a plug
connector which may be of very small size and still possess the
requisite resiliency to insure a tight connection.
A still further object of this invention is to provide a plug and
receptacle which may be economically mass produced with standard
machinery .
The foregoing and other objects and advantages of this invention
will appear from the following detailed description, taken in
connection with the accompanying drawings, in which:
FIG. 1 is an enlarged fragmentary section showing several
embodiments of the invention;
FIG. 1a is an enlarged fragmentary view of a portion of FIG. 1;
FIG. 2 is a sectional view in elevation of the connector plug
showing the introduction of pressurized elastic material
therein,
FIG. 3 is a sectional view in elevation of the plug in connector
which has been filled with compressed elastic material and crimped
to an electrical lead;
FIGS. 4, 5 and 6 are cross-sectional views of various embodiments
of the plug connector positioned in machine dies;
FIG. 7 is a sectional view in elevation of another embodiment of
the plug connector before the compressed elastic material has been
introduced therein;
FIG. 7a is a cross-sectional view of FIG. 7 taken along line 7a--7a
and viewed in the direction of the arrows;
FIG. 8 is a cross-sectional view of a further embodiment of the
plug connector;
FIG. 9 is a perspective view of another embodiment of the plug
connector;
FIG. 10 is a side elevational view of a further embodiment of the
plug connector;
FIG. 11 is a front end view of FIG. 10.
FIG. 12 is a perspective view of another embodiment of the plug
connector;
FIGS. 13 and 14 are side elevational views of further embodiments
of the plug connector;
FIG. 15 is a sectional view in elevation of a gas filled embodiment
of the plug connector;
FIG. 16 is a side elevational view of a further embodiment of the
plug connector;
FIG. 17 is a cross-sectional view of FIG. 18 taken along line
17--17 and viewed in the direction of the arrows;
FIG. 18 is a cross-sectional view of FIG. 16 taken along line
18--18 and viewed in the direction of the arrows;
FIG. 19 is a side elevational view of a still further embodiment of
the plug connector;
FIG. 20 is a cross-sectional view of FIG. 19 taken along line
20--20 and viewed in the direction of the arrows;
FIG. 21 is a cross-sectional view of FIG. 19 taken along line
21--21 and viewed in the direction of the arrows;
FIG. 22 is a sectional view in elevation of one embodiment of the
plug receptacle;
FIG. 23 is a sectional view in elevation of a gas filled embodiment
of the plug receptacle;
FIG. 24 is a perspective view of an edge connector embodiment of
the plug receptacle;
FIG. 25 is a top view of FIG. 22;
FIG. 26 is a top view of FIG. 23;
FIG. 27 is a longitudinal cross-sectional view of a further
embodiment of the receptacle;
FIG. 28 is a cross-sectional view of FIG. 27 taken along line
28--28 and viewed in the direction of the arrows;
FIG. 29 is a cross-sectional view of FIG. 24 taken along line
29--29 and viewed in the direction of the arrows.
FIGS. 1 AND 1a
Disposed within an orifice of circuit board B, is resilient
receptacle 2. Receptacle 2 is comprised basically of a conductive
sleeve or ferrule 4 of metal or a conductive plastic having a
portion 6 positioned on the surface 8 of circuit board B. The space
between the conductive sleeve 4 and the wall 10 of the orifice is
filled with an elastic material 11 under pressure. The outward
force exerted on the conductive sleeve 4 by this elastic material
11 results in a tight connection between receptacle 2 and plug
connector 12. Further description of the receptacle 2 will be taken
up in conjunction with a discussion of FIG. 22.
Plug connector 12 comprises a conductive sheath 14 and a core
receiving portion 16 integral therewith. The core receiving portion
16 is filled with an elastic material which is under pressure. This
core material 18 may be any substance which as a high degree of
elasticity when it is compressed, such as rubber or a resilient
plastic. Additionally this elastic material 18 may be either a
dielectric or a conductor.
A number of slots 24 have been cut out of the core receiving
portion 16. These slots 24 are separated from each other in a
circumferential direction by expansion ribs 26, i.e., the portions
of the core receiving sheath which remain. Since the expansion ribs
26 are structurally weakened by the absence of the sheath material
in the area of slots 24, they will bow out as a result of the
outward force exerted by the pressurized core material 18. When
with the expansion ribs 26 bow out, they come into contact with the
conductive sleeve 4. The force exerted by expansion ribs 26 on
conductive sleeve 4 causes connector 12 to be tightly secured by
receptacle 2.
When the connector 12 is inserted into receptacle 2, both the
elastic core 18 and elastic backing 11 are compressed and exert an
outward force bringing expansion ribs 26 and conductive sleeve 4
into a tight electrical connection. Additionally, this type
electrical connection effects extremely good wiping of the contact
surfaces 26 and 4 as the plug connector 12 is inserted.
Another embodiment of the plug connector is also shown in FIG. 1.
Plug connector 28 comprises a conductive plastic or metal sheath 32
of highly conductive and relatively noncompressible material and
having a hollow cylindrical core receiving portion 34 integral
therewith. It is obvious that the sheaths 4 or 32 may be of
non-conductive material having a conductive coating. A longitudinal
slot 36 is cut through the wall of core receiving portion 34 and
extends through the leading end 38 of the connector. When
pressurized core material (similar to material 18) is introduced
into the interior of core receiving portion 34, the resulting
outward force exerted by the core material on the inside walls of
sheat 34 will cause slot 36 to widen. This results in the core
receiving sheath 34 having a greater outside diameter than it did
before the material was introduced.
As shown in FIG. 1a, the core receiving sheath is provided with
locking means 40 to limit the degree to which slot 36 can widen. As
slot 36 widens and narrows, tongue 42 is allowed a limited amount
of movement in opening 44 which has been cut out of sheath 34.
The upper portion 45 of conductive sheath 32 has been crimped about
or otherwise secured to an electrical lead 46. A plug connector 28
is inserted into receptacle 48, the two edges of core receiving
portion 34 are brought together thereby narrowing slot 36. This
causes the core material disposed within portion 34 to be
compressed and the resulting outward force effects a tight
electrical connection between the outside surface of core receiving
portion 34 and receptacle wall 50.
FIGS. 2 THROUGH 6
The connector can be made as follows:
Hollow tubular member 52, made of expansible conductive material,
is crimped at one end by jaws 54 and 56 thereby forming a fluid
tight closure 57. Tubular member 52 is then filled with an elastic
material 58 which is injected under pressure into member 52 by
nozzle 60. Elastic material 58 is preferably pressurized and
compressed by the introduction of additional elastic materal 58.
The outward force exerted on the walls of member 52 by the
compressed material 58 causes an increase in the volume of spaced
enclosed within member 52. At this time jaws 62 and 64 crimp the
other end 65 of tubular member 52 forming a second fluid tight
closure 66. The pressurized material 58 is thereby enclosed within
the confines of tubular member 52 which remains in an expanded
position by itself. The crimping action of the jaws 62 and 64 cause
compression, building up a permanent pressure in the filled chamber
of tubular member 52.
FIG. 3 shows a plug connector 68 of the type made by the process
described in connection with FIG. 2. Closures 70 and 72 retain
pressurized material 74 within the confines of conductive sheat 76.
The portion 78 of conductive sheath 76 beyond neck 72 has been
crimped about electrical lead 80. When plug connector 68 is
inserted into a receptacle having a smaller diameter than the
diameter of connector 68, the outer circumference of conductive
sheath 76 will be reduced and the pressurized material 74
compressed. The outward force of material 74 exerted on the inner
wall 82 of conductive sheath 76 will urge conductive sheath 76 into
its enlarged position thereby effecting a tight electrical
connection.
A method of making the plug connectors shown in FIG. 1 is indicated
in FIG. 6. The conductive sheath 84 having a longitudinal slot 86
is encased in a machine die 88 having cooperating halves 90 and 92.
Pressurized elastic material 94 is then introduced into the hollow
interior of conductive sheath 84 and the two ends (not shown) of
sheath 84 are closed either permanently as by crimping or
temporarily by end capping with additional machine dies, (not
shown). The elastic material 94 is then allowed to solidify into a
semi-rigid stage and the die 92 is removed. When conductive sheath
84 is no longer restrained by die halves 90 and 92, the outward
force exerted by elastic material 94 will cause slot 86 to widen
and the outer circumference of conductive sheath 84 to
increase.
A similar process is employed to manufacture the type of plug
connector 12 shown in FIG. 1. FIG. 5 shows the connector encased in
die 96 which prevents the outward radial displacement of expansion
ribs 98. The area enclosed by die 96 and expansion ribs 98 is
filled with a pressurized elastic material 100, this area is sealed
and the material 100 is allowed to solidify. When die 96 is
removed, expansion ribs 98 will be forced to bow outwardly due to
the force exerted by the compressed elastic material 100. Since
elastic material 100 is now in a solid state, it will be contained
generally by expansion ribs 98.
In FIG. 4 is shown a slight variation on the type of die which was
used in the method of FIG. 5. In this instance, die 102 has a
number of recesses 104 in its inside surface 106 to receive
expansion ribs 108 when the connector is inserted in the die 102.
When elastic material 109 is introduced, allowed to solidify, and
the die 102 removed, the circumference defined by expansion ribs
108 will be greater than that defined by the outside surface 110 of
core 109. This will allow the expanded connector to be inserted
into an appropriate receptacle without the walls of the receptacle
coming into contact with the core 109. In this manner, the
frictional forces opposing insertion are minimized.
FIGS. 7, 8 AND 9
Instead of slotting the conductive sheath 112 of connector 114 as
was done in FIG. 1, portions 116 of the sheath wall 118 may be
thinned. FIG. 7 shows such a conductor in which the thinned
flexible areas 116 are annular and encompass the core area 120.
When the core area 120 is filled with a pressurized elastic
material (not shown) the thinned flexible areas 116 will expand due
to the internal pressure. Abutting the thinned flexible areas 116
are thick and relatively non-flexible areas 122 which will not be
substantially expanded. Obviously, too much internal pressure on
the flexible areas may cause balooning which, if excessive, may
make for difficult connection.
An additional embodiment is to form the conductive sheath 124
having longitudinal thinned portions 126 formed in its walls as
shown in FIG. 9. As was the case with the embodiment shown in FIG.
7, the introduction of pressurized material within core area 128
will cause the thinned portions 126 to expand outwardly.
FIG. 8 shows a further embodiment of the connector wherein the
conductive sheath 130 is fluted. The addition of pressurized
material within core area 132 will cause the depressed portions 134
to be displaced outwardly.
FIGS. 10 THROUGH 13
FIG. 10 shows yet another embodiment of the plug connector wherein
the core receiving portion 144 of conductive sheath 146 has a
series of longitudinal slots 148 cut into it. These slots are
circumferentially separated from one another by a series of
expansion ribs 150 comprising the non-slotted portion of core
receiving sheath 144. When pressurized core material 152 is
introduced into core receiving portion 144, expansion ribs 150 bow
outwardly.
In FIG. 13, core receiving sheath 154 has a number of generally U
or V-shaped slots 156 cut into it. When pressurized core material
is introduced into the core receiving sheath, the tongue portions
158 will be displaced outwardly. This type of connector would be
useful in conjunction with a receptacle (not shown) having a ridge
or the like on its inside wall thereby preventing or making
difficult the removal of the inserted connector.
FIG. 12 shows an embodiment of the plug connector closely related
to the one shown in FIG. 9. In this instance, the longitudinal
thinned portions 160 are formed by removing a portion of the
outside surface 162 of core receiving sheath 164. Additionally, a
slot 166 has been cut through the wall of sheath 164.
FIG. 14 shows a further embodiment of the plug connector wherein
the core receiving portion 168 has a helical slot 170 cut in it.
When pressurized core material 172 is introduced into the volume
encompassed by sheath 168, the external circumference of core
receiving sheath 168 will be increased due to the"cork screwing"
effect of the helical strip 174 running adjacent to slot 170.
FIG. 15
A further variation would be to introduce a gas into the expansion
chamber 176 of conductive sheath 178, increase the pressure of the
gas until the walls 180 of expansion chamber 176 are are expanded
outwardly, and then seal expansion chamber 176 by means of a plug
182.
FIGS. 16 THROUGH 21
In FIG. 16 the core receiving portion 184 is formed in the shape of
a J enclosing a core of elastic material 186. With this design, leg
188 pivots about bend 190 contracting and releasing the core
material 186 enclosed within.
In FIG. 19 the expansible core receiving portion 192 is U-shaped
and the ends of the U are secured together by a retaining ring 194.
As is best shown in FIG. 21, the core receiving portion 192 has a
rectangular cross-section.
FIGS. 22, 23, 25, 26, 27, AND 28
In addition to the plug-type connector previously described,
basically the same design consideration may be applied to a
connector receptacle. The broad aspects of this were considered in
connection with FIG. 1.
Installed in circuit board B is a receptacle 196 comprising a
conductive plastic or metal sleeve or ferrule 198 to which is
attached a backing 200 of elastic material under compression. This
backing material 200 is supported by the conductive sleeve 198 and
exerts an expansion force on its inside surface 202. The backing
material 200 is further supported by the wall 204 of the circuit
board B. Cut into conductive sleeve 198 is a slot 206 to allow the
inside circumference of conductive sleeve 198 to increase and
decrease. Since conductive member 198 is made of a material harder
and substantially less compressible than the elastic backing
material 200, the introduction of a plug and connector (not shown)
having a circumference greater than the inner circumference of
sleeve 198 will cause this inner circumference to be increased
resulting in the widening of slot 206 and the compression of
backing material 200. The inner circumference of sleeve 198 is
prevented from decreasing beyond a certain limit by adjoining edges
208 and 210 abutting against each other. In electrical contact with
inner sleeve 198 are printed circuit leads 212 and 214.
As shown in FIG. 23, an additional embodiment of the tight fitting
receptacle is to mount a number of air tight plastic envelopes 216
in circuit board B. The conductive sleeve 218, having a slot 220,
is secured to the backing envelopes 216 and printed circuit lead
222. When gas is introduced into the expansion chambers 224, the
flexible backing envelopes 216 will expand thereby decreasing the
inner curcumference of conductive sleeve 218 in the manner
previously described.
Additionally, as is shown in FIG. 27, the tight fitting receptacle
226 may comprise an inner conductive sleeve 228, having a slot 230
therein, and an outer concentric sleeve 232. When the expansion
chamber, which lies between the two sleeves, 232 the 228, is filled
with a pressurized core material 236, the inner circumference of
the inner sleeve 228 will decrease in the manner previously
described. The outer sleeve 232, not being slotted, will undergo no
expansion.
FIGS. 24 AND 29
A further embodiment of the tight fitting receptacle is the edge
connector shown in FIG. 24. This type of connector would be useful
where it is desired to make a multiple connection to a printed
circuit board or the like.
The edge connector 237 comprises a base 238 having a slot 240
therein. Retained or supported by the skirts 242 and 244 are
parallel strips of backing 246 and 248 of elastic material under
compression. Further supporting and containing the backing stip 246
and 248 are a pair of spaced plates 250 and 252. The spaced plates
250 and 252 are movable due to the space between the ends 254 and
256 of the plates and the tongue 258. As plates 250 and 252 are
displaced in directions opposite to each other, e.g., due to the
insertion of an edge connector, the elastic backing stips 246 and
248 are compressed. This affords a gripping action on the inserted
connector (not shown).
To provide electrical connection between the inserted connector
(not shown) and the printed circuit leads 260 and contact strips
262 may be printed or electrodeposited on the surface of plates 250
and 252, or otherwise manufactured.
While this invention has been described in connection with
different embodiments thereof, it will be understood that it is
capable of further modifications, and this application is intended
to cover any variations, uses, or adaptations of the invention
following, in general, the principles of the invention and
including such departures from the present disclosure as come
within known or customary practice in the art to which the
invention pertains, and as may be applied to the essential features
hereinbefore set forth and followed in the scope of the invention
or the limits of the appended claims.
* * * * *