Note: Descriptions are shown in the official language in which they were submitted.
:~2~33~L
T~ER~AL,LY R~,PONSIVE ELECTRICAL CO~M~CTOR
~ACKGROUND OF T~lE INVE~1TIO~
It is often necessary to connect or disconnect
conductors (or contacts) along one electrical cornponent
5 with corresponding conductors (or contacts) along another
electrical component.
Moreover, it is often desired that such connection
(or disconnection) be convenient, e~fective and perform-
able in an area inaccessible hy tools.
It is also often desired that connection (or
disconnection) be ef~ectuated with a zero insertion (or
removal) force. I'his feature may he required to prevent
damaqe to the components being connected.
In a~dition, it is typically desired in numerous
15 applications of electrical connectors to provide connec-
tion between closely spaced parallel _onductors, to pro-
vide high strength closure; and high resistance to shock
and vibratiorl. Conventional approaches which teach
separate coupling elements ~or each conductor on one com-
20 ponent to be connected to a corresponding conductor on asecond corrporlent have rendered such features difficult to
attain.
SI~MARY OF THE INVE~ITION
In accordance with the invention, an electrical
25 connector is provided which reali~es the aforementioned
features as ohjects.
The present invention relates preferably to a
multipin electrical connector including (a) male member
having a plurality of conductors thereon extending
30 longitudinally in parallel and (b) a female member that
includes a split tube to receive the rrale member. A
plurality of parallel conductors on the female rnember
extend along the inside of the split tube which receives
the rnale member. ~ plurality of parallel conductors o~
2 ~'~Z3;3~f~
the female member extend along t'ne inside of the split
tube are spaced to correspond with the conductors along
the male members. The male member has an enlarged edge
that is insertable into the split tube so that each con-
5 ductor along the inside of the split tube faces a corre-
sponding conductor along the enlarged edge of the male
member. '~le split tube comprlses Nitinol or some other
shape memory material which is biased open (or closed) and
which, upon heating to a transition temperature, changes
10 dirnensions to engage (or disengage) the inserted male
member.
Such a connector features zero insertion force,
high strength, close conductor spacing, and high shock
resistance. Upon closure, the conductors along the male
15 member cont~ct corresponding conductors along the split
tube .
Preferably, the invention pertains to an
e]ec-trical connector for coupling two strips together.
The first strip has a split tube forming one edge thereof,
20 the split of the tube being selectively opened and closed.
The second strip is inserted into t'ne split when the tube
is open, whereupon the tube may be closed to effect
coupling of the two strips.
In accordance with the invention, the second strip
25 may include at least one conductor therealong which is to
be coupled to a corresponding conductor along the first
strip. Typically, parallel conductors on the upper sur-
face and on the lower surface of the second strip are
couplable to corresponding conductors of ~he first strip
30 by closure of the split tube thereagainst.
In one embodiment, the conductors along the upper
surface of the second strip are separate and indpendent
from the conductors along the lower surface thereof.
Also, conductors along the first strip can similarly be
35 defined with (a) an upper plurality of conductors that can
close against conductors along the second strip upper
surface and (b~ a lower plurality of conductors
independent of the upper plurality that can close against
conductors along the second strip lower surface. Hence, a
4Q double connector is provided wherein a plurality of con-
3 ~Z~33~
nections can be effected in an up er plane separately anddistinct from connections effected in a lower plane. ~nat
i5, where x conductors are provide~ along the upper sur-
face and x conductors are provided along the lower surface
5 of the second strip, 2x connections can be made.
In a second embodiment, conductors along the upper
surface oE the second strip extend into the conductors
along the lower surface. Similarly, the upper plurality
of conductors of the first strip may extend into the lower
10 plurality of conductors. This is a single connector
embodiment. This arrangement provides an upper area and a
lower area of electrical contact for each conductor.
Hybrid embodiments w~ich vary from the above two
embodiments -- the single connector and double connector
15 -- may include main-taining some of the conductors on -tne
upper surface of the second strip independent of the
conductors on the lower strip while other conductors on
the upper strip extend into conductors on the lower strip.
Also, it is envisioned that all conductors along
20 the upper strip extend into the conduc-tors along the lower
strip of the second strip whereas all conductors in the
upper plurality of the first strip do not extend into
conductors in the lower plurali-ty. Accordingly, two sets
of lines connected respectively to the upper plurality of
the first strip and to tlle lower plurality of the first
strip may be interconnected upon closure against the
second strip, as well as providing connection between the
conductors on the first strip and second strip.
In the various embodiments it is contemplated that
the split tube include at least a shape mernory layer
formedt preferably, of a shape memory metal such as a
nickel titanium alloy. More speci~ically, it is preferred
that the split tube comprise coaxial layers which include
a shape memory layer, a stainless steel layer disposed
about the shape rnemory layer, and a flexible plastic layer
-- into which conductors are imbedded -- enclosing the
split tube. Depending on how heat is applied to the shape
memory layer, a heater elemen-t may be provided adjacent
- the shape memory layer along the portion of the flexibLe
plastic layer which inscribes the spli-t tube.
4 ~3~
To provide a locked coupling, the edge of the
second strip inserted into the interior of the split tube
is enlarged.
In accordance with the invention, closure of the
5 connector is performed by heating a shape memory layer to
a characteristic transition temperature. It is, however,
contemplated that opening of the connector may also be
performed by heatina a shape memory layer to a charac-
teristic transition temperature. It is known that a shape
10 memory metal in its memory shape displays high strength;
thus the closure or opening to a memory shape results in a
hio~ strength configuration.
~RIFF_D~CRIPTION OF DRA~INGS
Fi~ure I is an upper back left perspective view
15 illustrating a connector according to the invention.
Figures II through V are side-view illustrations
showing the operation of the connector of Figure I.
Figure VI is an illustration of one embodiment of
an element formable into a first strip shown in Figure I.
Figure VII is an illustration of one embodiment of
an element formable into a second strip shown in Figure I.
Figure VIII i5 an upper front left perspective
view oE a double connector formed from the first strip of
Figure VI and the second strip of Fi~ure VII.
Figure IX is an alternative embodiment of an
element formable into a second strip shown in Figure I.
Figures X and XI are perspective and side view
illustrations of the invention including a cover.
DESCRIPTION OF TH~ INVRNTION
In Figure I, one embodiment of an electrical
connector 100 according to the invention is illustrated.
The connector 100 is shwon including a first strip
102 which terminates in a split tube 104. The split tube
104 is shown for~ed of a plurality of coaxial layers.
5 ~3~
Extending peripherally a~out the split tu~e 104 is a
flexible plastic layer 106 which serves to inscribe and
circumscribe the split tube 104. That is, the flexible
plastic layer 106 extends along a flat two-layer portion
5 107 of the first strip 102, passes circumferentially to an
upyer lip 108 whereupon the pLastic layer 106 traces the
inner surface of-the split tube 104 to a lower lip 110.
From the lower lip 110, the plastic layer 104 follows the
lower outer circumference of the split tuhe 104 back to
10 the flat portion 107 o;f the first strip 102. The flat
portion 107 comprises two plastic layers that lie against
each other as a laminate.
The split tube 104 also includes a shape memory
layer 112 about which is disposed another layer 114. ~ne
15 layer 114 is preferably stainless steel. The shape memory
layer 112 and layer 114 are enclosed by the flexible
plastic layer 106.
Provided along the inscribing portion of the
flexible plastic layer 106 is a flexible heater 120 of a
20 construction known in the art. The heater 120 is adjacent
the shape memory layer 112 to direct hea-t thereto.
Also provided a]ong the flexible plastic layer 106
are parallel conductors 130, 132, and 134 (the num~er
being variable) along the upper layer 126 of the first
25 strip 102. Along the lower layer 128 of the first strip
102 are parallel conductors 136, 13~, and 140. Each
conductor 130 through 134 extends along the flat portion
107 to follow an outer circumscribing path toward and
around the upper lip 108. Each conductor 136 through 140
follows a similar path along the lower layer 128 of the
first strip 102. As discussed below, the conductors 130
through 134 along the upper layer 126 may or may not
extend into corresponding conductors 13h through 140 along
the lower layer 128 depending on embodiment.
Preferably, the conductors 130 through 140, as
well as the heater 120, are embedded in the flexible
plastic layer 106 to enhance durability, shock and impact
resistance, integrity of structure, and strength and to
maintain the relative positions of conductors and heater
40 strips. That is, the conductors 130 through 140 and
~3~
heater 120 are covered by plastic layer 106. To expose
the conductors to permit electrical contact th~rewith --
as by pressing another conductor thereagainst -- windows
are provided in the plastic layer 106 where contact is to
5 be macle. As described below, the windows expose at least
those portions of the conductors 130 through 140 along the
upper lip 108 and the lower lip 110. The space there-
between, it is noted, defines the split of the tube 104
between which a second strip 150 is inser-table.
The second strip 150 includes two flexible plastic
layers 152 and 154 lying coextensively against each other.
The upper layer 152 has conductors 160 through 164 there-
along. The lo~er layer 154 also has conductors 166
through 170 (not shown) extending theralong. To expose
15 the conductors 160 through 164, a window 174 is provided
in the upper layer 152. A similar window is preferably
provided in the lower layer 154 also.
The second strip 150 also includes an enlarged
edge 176 which is insertab]e into the interior of the
20 split tube 104. (The edge 176 is enlarged by inserting a
rod or the like between the two layers 150 and 152 at the
fold therebetween.) By enlarging the edge 176, the two
strips 102 and 150 cannot be pulled apart after the split
tube 104 is closed with the edge 176 inserted. Specifi-
25 cally, the edge 176 preferably abuts the upper lip 108 andthe lower lip 110 upon closure to effectuate the desired
locking effect.
The connector 100 in Figure I is shown with the
split tube 104 closed. To enable the second strip 150 to
30 be inserted, the split tube 104 is deformed to open the
split. In this regard, it is noted that the shape memory
layer 112 may serve to either open the tube 104 from a
closed position or close the tube 104 from an open
position. Whether the shape memory layer 112 acts to open
35 or to close the tube 104 depends on the memory shape
imparted to the layer 112. The shape memory layer 112
comprises a material that can be ormed to a predefined
memory shape or configuration. A~ter the memory shape is
defined, the material can be deformed and, by bringing the
~0 material to a characteristic transition temperature,
7 ~ 3~ ~
returned (or recovered) to the memory shape. Althoug~n
various plastics feature heat recoverable memory, it is
preferred that ~he shape memory layer 112 be a metal which
undergoes transition such as a nickel titanium alloy, or
5 Nitinol.~
The operation of Nitinol and o-ther alloys which
exhibit such memory or recovery from a heat unstable state
is discussed in various references and is not elaborated
on here. Reference is made, however, to U.S. Patent No.
10 3,606,592 to Madurski et al and to U.S. Patent No.4,018,547
to Rogen which describe the shape memory phenomenon~
In brief, Nitinol has a tempexature above which the memory
configuration is set. By holding the Nitinol to a given
shape at such temperature (e.g. approximately 900F for
lS 55-Nitinol), the memory configuration becomes fixed.
Nitinol also has a transition temperature range (~TR)
below which the alloy is ductile and may be plastically
deformed and above which recovery occurs. Raising the
alloy to temperatures above the TTR, then, causes atoms of
20 the alloy displaced during deformation to return their
predeformed positions. Accordingly, Nitinol and similar
alloys characterized with memory shape can be repeatedly
deformed and recovered in alternation by applying pressure
to the Nitinol when below the TTR and by heating the alloy
25 to recovery temperatures thereafter. As is known in the
art, the TTR, or recovery temperatures, may be determined
between -60~F and +300F by proper selection of alloy.
In the preferred mode, the shape memory layer 112
acts to open the tube 104. The tube 104 is closed by a
30 spring force provided by the layer 114. The spring Eorce
is sufficient to close the tube 104 when the shape memory
layer 112 i5 ductile and soft (below the transition tem-
perature of Nitinol, for example) but is overpowered by
the shape memory layer 112 upon recovery thereof.
35 Alternatively, although not preferred, the tube 104 may be
deformed closed by means of a tool, if the layer 114 is
not desired or provided.
Although the connector 100 may vary greatly in
dimensions based on use, sample dimensions include: an
* Trademark
~2~33~
outer diameter of .120 inches for the tube 104 when
closed, a .020 inch thickness o~ layer 112, a .015 inc'n
tllickness of layer 114, an inner "diameter" of the tube
104 (when open) of .022 inch and a plastic layer 106
5 having dimensions oE a conventional flexstrip.
Figures II through V illustrate the operation of
the connector 100. In Figure II, the connector 100 is
closed (by the layer 114) with the upper lip 108 of tube
104 abutting the lower lip 110. In Figure III, the tube
10 104 is opened by heating the shape memory layer 112 to
enable the second strip 150 with its enlarged edge 176 to
be inserted as shown in Figure IV. The heating is
provided by heater 120. Other sources of heat may also be
employed. ~iscontinuing the heating results in the
15 closure of the upper lip 108 and lower lip 110 with the
second strip 150 therebetween. The window 174 (see Figure
I) of the second strip 150 is aligned with the upper lip
102 -- and a corresponding window along the lower layer
154 (see Figure I) is also aligned with the lower lip 110
20 following insertion and closure. By providing windows
along -the upper lip 108, the conductors 130 through 134
are pressed against the conductors 160 through 164,
respectively, making electrical contact therewith.
Similarly, by providing windows along the lower lip 110,
25 the conductors 136 through 140 a~e pressed against the
conductors 166 through 170, respectively, making electri-
cal contact therewith.
In Figure VI, one embodiment of a first strip 200
is shown beore it i5 structured as in Figure I. Figure
30 VI shows two windows 201 and 202 which lie along the upper
lip 108 and the lower lip 110, respectively, when formed
as Figure I. Connectors 204 through 216 are embedded in
flexible plastic 218. These conductors 204 through 216
may be considered to lie along the "upper" layer of the
35 first strip as illustrated in Figure I. The conductors
204 through 216 end just beyond the window 201. Con-
ductors 224 through 236 similarly end just beyond the
window 202. Also embedded in the plastic 218 is a heater
element 240 with lead.s connectable thereto to produce
40 heating.
Figure VII shows an embodlment of t'ne second strip
300 formable into a structure like that shown in Figure I
by folding along line K. One window 301 is shown exposing
conductors 304 through 318 embedded in the "upper" layer
5 320 of plastic 322. Conductors 324 through 338 are
provided in the "lower" layer 340 being exposed through
window 302.
Figure VIII shows a perspective of a connector
formed from a first strlp 200 as in Figure VI and the
10 second strip 300 as in Figure VII. Figure VIII shows a
double connector wherein conductors 206' through 210' are
separate from -- i.e. do not extend into -- conduc-tors
along the lower plane, e.g. conductors 224 through 236 of
Figure VI, and wherein conductors 308' through 312' do not
15 extend into conductors along the lower plane suc'n as
conductors 324 through 338 of Figure VII. Accordingly,
six conductors (as illustrated) of the first strip 200'
can separately and distinctly connect -to six conductors of
the second strip 300'. That is, there is an upper plane
20 of con~ections that can be made ~by pairs 206'-326', 208'-
328', 210'-330') and a similar lower plane of connections
that can be ~ade.
Turning to Figure IX, a second strip 400 for use
in a single connector is shown. Specifically, eac'n
25 conductor 406 through 420 in the upper layer 422 ~olds
back to extend along the lower layer 424 when the second
strip 400 is creased along line L-L. In the single
connector, each conductor of the first strip (not shown)
also extends the length of the plastic -- each conductor
30 406 through 420 being exposed through both windows 430 and
432 to make electrical contact with a corresponding
conductor of the first strip.
~ lybrid embodiments w~ich vary from the above two
embodiments -- the single connector and double connector
35 -~ may include maintaining some of the conductors on the
upper surface of the second strip while other conductors
on the upper strip extend into conductors on the lower
strip.
Also, it is envisioned that all conductors along
40 the upper strip extend into t~e conductors along the lower
~2~
strip of the second strip whereas all conductors in the
upper plurality of the first strip do not extend into
conductors in the lower plurality. Accordingly, two pairs
of lines connected respectively, to the upper plurality of
5 the first strip and to the lower plurality of the first
strip may be interconnec-ted upon closure against tne
second strip, as well as providing connection between the
conductors on the first strip and second strip.
In Figures X and XI, a cover 500 is shown
10 enclosing a tube 502 wit'n shape rnemory layer 504,
stainless steel layer 506, heater 508, and plastic layer
510. The cover 500 has a slot 512 for receiving the
second strip 514 with a locking edge 516.
According to the invention, conductors along the
15 first strip engaging corresponding conduc-tors along the
second strip to make electrical contact therewith. when
the conductors are embedded in, or covered by, plastic
windows are required to enable the contact. If the
conductors lie along or pro-trude from -the plastic rat'ner
20 than being embedded totally within, the windows may not be
required~
