CA1061877A - Louvered connectors and contact elements thereof - Google Patents
Louvered connectors and contact elements thereofInfo
- Publication number
- CA1061877A CA1061877A CA234,864A CA234864A CA1061877A CA 1061877 A CA1061877 A CA 1061877A CA 234864 A CA234864 A CA 234864A CA 1061877 A CA1061877 A CA 1061877A
- Authority
- CA
- Canada
- Prior art keywords
- contact
- strip
- finger
- fingers
- extremity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
- H01R13/02—Contact members
- H01R13/15—Pins, blades or sockets having separate spring member for producing or increasing contact pressure
- H01R13/187—Pins, blades or sockets having separate spring member for producing or increasing contact pressure with spring member in the socket
Landscapes
- Coupling Device And Connection With Printed Circuit (AREA)
- Contacts (AREA)
- Connector Housings Or Holding Contact Members (AREA)
- Details Of Connecting Devices For Male And Female Coupling (AREA)
- Testing Or Measuring Of Semiconductors Or The Like (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Connectors having strip member contact elements wherein louvers or contact fingers extend in dissimilar ex-tents from opposed sides of the strip member. Method is also disclosed for enhancing contact surface area between the ex-tremities of contact fingers and complementary contact surfaces.
Connectors having strip member contact elements wherein louvers or contact fingers extend in dissimilar ex-tents from opposed sides of the strip member. Method is also disclosed for enhancing contact surface area between the ex-tremities of contact fingers and complementary contact surfaces.
Description
10~ il77 Fleld of the Invention This lnvention relates generally to electrical connectors and contacts thereof and more particularly to electrical contacts of the type having resllient contact fingers for resiliently en-S gaging a complementary contact ~urface.
Background of the Invention Rnown connectors with contacts having contact fingers in resilient engagement with a complementary contact surface, 30-called "louvered connectors", such as are illustrated in Neidecker U.S. Patent No. 3,453,587 and Crabbs U.S. Patent No. 2,217,433, typically comprise elongate conductive strip members having a plurality of longitudi~al~y spaced transverse openings defining longitudinally and transversely extending expanses therebetween which are bent or twisted with respect to the strip member so as to define contact fingers having opposed ~xtremities displaced from respective opposite ~urfaces of the strip member. It is com-mon to deploy these contacts by havlng the strip member ends dis-, posed in a juxtaposed manner so as to provide a contact element '~ having a substantially circuIar interior into which a male contact in the form of a pin member is insertable. The pin member diameterbeing greater than the diameter of the locus of the radially inter-ior extremities of the contact fingers, the contact fingers are res~liently flexed upon pln member insertion and resiliently engage the same under sufficient contact pressure to provide electrical contact therewith. The strip mem~er finger extremi.ties extend~ng radially exteriorly of ~he strip member engage the walls of a ., .
_ /_ .' ' D
".... . ..
'7 socket seating the contact element whereby an electrlcal path capable of tran ferring current~ of relatively high magnitudes i~
provided between the pin member and the socket.
Performance considerations of presently known connectors and contacts of this type are several in number. Secure engagement of course need be provided between the separable connector parts, ~ i.e., the pin member and the radially interiorly extending contact ;~ finger parts. This consideration necessitates careful control of manufacturing tolerances as between pin member diameter and con-- 10 tact element interior diameter, directly affectlng manufacturing ; C09t3. Secondly, the resistance of the electrical connector to current flow therethrough is dependent to a large degree on sur-face contact area as between the contact fingers and hoth the pin member and the sock~t, engagement of the radially interior contact finger extremities and pin member belng most significant since they are repeatedly separable in connector use. Reliability of this type of connector is also dependent on the cooperation of the contact element and the socket such that the former is not readily removable from the latter, giving rise to manufacturing tolerance control respecting the socket recess provided for containment of the contact element.
Known connectors of this type are not considered to readily exhibit the foregoing performance characteristics to the degree desired. Thus, unduly close manufacturing tolerances are demanded by existing connector structures of this type. Surface area engagement of the ~eparable surfaces is regarded as less than : - 2 -V
adequate for certain applications in which particularly low con-nector electrical resistance is desired. Finally, in the absence of structure, additional to the electically functioning parts of the contact element and socket themselves, for securely seatlng the contact element in the ~ocket, the contact element has been observed to ~e separable from the socket upon manipulatlon of the pin member.
Summary of the Invention It i~ an o~ject of the pre~ent invention to provide impro~ed connectors of the su~ect type, exhibiting improvements over presently-known louvered connectors in each of the perform-ance considerations discussed above.
According to the present invention there is provided an electrical contact adapted to be formed into a cylinder for inter-position between a socket portion of an electrical connector and a . . _ - .
male contact element''~f the electrical connector, said electrical contact comprising a strip of electrically conductive material having a plurality of conductive fingers extending transversely '; across the greater part of the strip and pro~ecting out of the plane thereof, said fingers being integral with said strip and supported thereby for resilient flexure between a normal position and a deflected position, ~aid fingers being adapted to be flexed in use by said male contact element into the deflected position and having a curved end contact surface extending across substantially the entire width of the finger and adapted to engage said male contact element ~aid end contact surface being recessed into said fingers and having a first configuration in the normal position and - a second configuration, different from the first configuration, in the deflected position, said second configuration being complementary to the surface of said male contact element so that said male contact element contacts said end surface ~ubstantially over the . . - - ~
'7~7 whole area thereof.
According to a further aspect of the inventlon there is provided a method of making an el~ctrical contact having re-silient contact flngers engageable with a complementary electrical s contact element including the steps of forming transverse openinga through opposed first and Yecond flat surfaces of an elongated strip member, displaclng outwardly of said strlp member first surface an end portion of each strip member portion between adjacent transverse boundaries of successive such openlngs, forming said strip member ; 10 into a cyl~r with said end portions of said strip m~er portions thereof ex-tending to~d the interior of said cyl ~ er, insertlng into the interior of said cylinder a cylindrical hone of diameter greater than the diameter of the locus d the extremities o~ sald end portions and e~ual to the diameter of said-complementary contact element, and rotating said hone, thereby re-lS moving a part of each said end portion to define a curved end con-tact surface, recessed at the extremity of each said end portion, the fingers being such that upon resilient engagement of the end portions with the electrical contact element the end contact surfaces each change from a first configuration to a second configuration different from the first configuration, the end contact surfaces of said end portions in said second configuration being complement-ary with the surface of said ~ectrical contact element.
The foregoing and other objects and features of the in-vention will be evident from the following detailed description of preferred embodiments thereof as illustrated in the drawings where-in like reference numerals identify like parts throughout.
Brief Description of t~e Drawings Fig. 1 is a plan view of an apertured strip member before expanses between adjacent openings therein are displaced outwardly -30 of the openings to deflne contact fingers.
Fig. 2 is a side elevational view of the strip member of Fig. 1 after expanses between adjacent openings therein are dis-placed outwardly of the openings to define contact flngers.
Fig. 3 is a side elevational view, partly in section and partly broken away to show detail, of a connector employing the strip member of Fig. 2 as a contact between a pin member and a socket.
Fig. 4(a) is a sectional view as seen from the plane IV-IV of Fig. 3.
Fig. 4~b) is a ~ectional ~iewof an alternative embodiment _ ~ _ D
iU~ 7~
of a connector in accordance with the lnventlon.
Fig. 5 is an enlarged partial sectional view of a fur-ther alternative embodiment of a connector in accordance with the invention showing radially inward contact finger parts in engage-,5 ment with a complementary contact surface.
Fig. 6~a) illuQtrates the configuration of the Fig. 5contact finger parts when resiliently ~lexed and Fig. 6tb~ illus-trates ~uch configuration under non-flexed condition.
Fig. 7 is an enlarged partial elevational view of a still further embodiment of a connector in accordance wi~h the invention.
Fig. 8 is a plan view of a further embodiment of the strip member shown in Fig. 1.
Description of the_Preferred Embodiments Referring to Figs. 1 and 2, elongate strip member 10 is comprised of electrically conductive material and includes a series of longitudinally spaced transverse openings 12, 14 extend-ing through opposed first and second surfaces lQa and lOb. Con-sidering the leftwardmost pair of open~ngs, the strip member de-fines a continuous longitudinally and transversely extending ex-panse 16 therebetween, bordered by respectlvely adjacent trans-verse edges or boundaries 12a and 14a of these openings. Expanse~
16 is disposed or displaced angularly outward~ly of these openings, such as by twi~ting, about a transverse axis 18, which axis is located longltudinally closer to one o~ such edges than it is to the other thereof. In the case of axis 18, which i9 longitudinally - closer to edge 12a than to edge 14a, a first part 16a of expanse 16 is disposed, as shown in Fig. 2, at an acute angle ~ relative to strip member surface lOa and a second part 16b of expanse 16 is disposed at an acute angle ~ relative to strip member surface lOb, with first part 16a b~eing of greater longitudinal extent than second part 16b. Upon such twisting of expanse 16, the same defines a contact finger or louver.
So prepared, the strip member then is formed into a cylindrical or ring-like shape with contact finger parts 16a extending radlally inward ~f such cylinder and contact fingers parts 16b extending radially outward of the cylinder, as shown in Figs.
' .
r~
i(~tilt~77 3 and 4ta). This arrangement provides a female contact element 20 which, when seated ln socket 24 of housing 25, as depicted in Fig. 3, reslliently engage~ the encircling housing wall through - extremlties 16d of finger parts 16b, and i9 adapted for receiving a male contact element in the ~orm of a cylindrically-shaped pin member 22, which latter will be resiliently engaged by sharp con-tact edges 16Cl of each of extremities 16c of finger parts 16a.
A recess 26 is provided in socket 24 for seating contact element 20 and retalning it against withdrawal. The housing socket dia-meter is slightly greater than the pin member outer diameter, withthe latter greater than the locus of extremities 16c of the con-tact fingers when the pin member is not receivably engaged within the female contact element 20 in housing socket 24. The contact fingers accordingly provide electrical connection between the pin member and the housing when the pin member is received within the housing soc~et substantially as shown in Figs. 3 and 4(a~.
Various advantages attend the asymmetrical longitudinal relation existing among the twist axis and the respectively adjac-ent edges of successive ~trip member openings. In one aspect, the radially interior contact finger parts 16a encompass a major extent of the combined parts 16a and 16b of the contact fingers. Parts 16a thus constitute radially interior spring elements of greater longitudinal extent than those of the above-referenced known louvered connectors, which are derived from twisting of the strip member expanse about a transverse axis symmetrically disposed relative to respectively ad~acent transverse edges of successive strip member openings. Since spring rate, i.e., the ratio of load - 6 -`
Y
: . .
lU~ 7 to spring deflection, i~ lnversely proportlonal to spring longi-tudinal extent, thls geometry o~ the invention provides for lower spring rate for the interior contact finger part than in known louvered connectors (the ~pring material, its thickness and it~
S width being the same). As a recult, lt has been found that re-silient engagement of contact fingers of connectors constructed - in accordance with the invention providing desired electrical contact occurs for pin members varying over a greater range in diameter than is the case for otherwise like pri0r louvered con-nector~. Manufacturing tolerances as between the locus of the extremlties of interior contact finger parts and pin diameter i~
thereby relaxed, giving rise to lowered costs in manufacture.
Apart from this advantage attending increased longi-tudinal extent of radially interior contact finger parts, further advantage attendq the conse~uent reduction in length of radially exterior contact finger parts. With yart 16b having longitud~nal extent reduced as compared to like elements in the symmetrical twist axis case of known ?ouvered connectors, the radial depth of the housing recess seating the ctrip member may be lessened, giving rise to reduced manufacturlng cost. Alternatively, for the same radial recess depth as in known louvered connectors, strip members of the invention are seated more deeply therein and hence are les~ su3ceptible to remcval on manipulation of the pin member.
The asymmetry in contact finger parts may be attained and the foregoing advantages realized without need for displacing :, i ;'7 the entirety of expan~e 16 outwardly of the strip member openings.
Thus, contact flnger part3 16a and 16b may comprise opposed end portions of such strip member expanse displaced outwardly of the strip member openings, with one such end portion being of greater S longitudinal extent than the other. The strip member is then formed into cylindricaI shape as discussed above, such that the radially interior end portions are of greater longitudinal extent than the radially exterior end portions. In the particularly preferred embodiment, however, the sum of the longitudinal extent~
of the respective opposed end portions of each contact finger equals the longitudlnal extent of the strip member c~ntinuous expanse defining such contact flnger.
Referring now to the c~nnector embodiment of Fig. 4(b), the contact fingers are formed by asymmetrical twisting but are disposed at an angle less than angle ~ of Fig. 2, whereby contact ., .
finger parts 16a are ln other than sharp contact edge engagement ~ with pin member 22. That is, in the embodiment of Fig. 4(b), con-tact is achieved by resilient engagement between elongate flat i~ surface 16e of each contact finger and the surface of the cylin-` 20 drical pin mem~er. Such Fig. 4~b) arrangement provides surface area contact between parts 16a and pin member 22 increased over that obtainlng in endwise engagement, such as the sharp contact edge engagement de9cribed in Flg. 4~a) above. In accordance with `- another aspect of the invention, the contact finger extremities may be prepared as now discussed in connection with Figs. 5, 6(a) and 6(b).
. .
10~ 77 As shown in Figs. 5 and 6(b), each contact finger part 16a includes opposed elongate flat surfaces 16e, 16f extending to the extremity 16c thereof displaced from strip member surface lOa. At extremity 16c, a surved end contact surface 16g extends from at least one of surfaces 16e and 16f, for example, it ex-tends from surface 16e as shown, toward the other surface 16f.
At extremity 16c, a flat end surface is provided in a plane other than, and preferably in a plane orthogonal to, the planes of elongate flat surfaces 16e and 16f. Curved end contact surface 16g intersects such extremity flat end surface over substantially the entire transverse extent of the extremity thereof, the inter-section between curved end contact surface 16g and the flat end surface defining a curved common boundary 16C2 for such flat end surface and curved end contact surface 16g. It will be noted that the curvature of such common boundary 16C2 occurs entirely within the plane defined by the flat end surface of extremity 16c. ~-Such curved end contact surface 16g may be located other than at extremity 16c, e.g., in the case where contact is to be made as in Fig. 4(b) the surface 16g may be included as a : portion of the elongate flat surface 16e at a position displaced from the flat end surface of extremity 16c.
; In forming surface 16g, material is removed from extrem-ity 16c, when the finger is in its flexed condition as shown in Fig. 6(a), until the curved end contact surface 16g is defined.
The broken line outline in Fig. 6(a) indicates the original con-; figuration of the finger prior to the removal of such material ' when the finger is in the flexed condition, whereas the broken ;~
line outline in Fig. 6(b) indicates the original configuration of the finger prior to the removal of such material and when the -finger is in its unflexed condition.
_ g _ ~, . .
'7 Preferably, this materlal remo~al i9 effected by forming the strip member into contact element 20 as in Flgs.
1-4, seating the same in housing 25 and lnserting a hone in the shape and size ~particularly outer diameter) of pin member 22 into the contact element interlor, thus causing the contact finger parts to flex inbo resllient engagement with the hone outer surface. Under such loading each contact ~inger part assumes the configuration shown in Flg. 6ta), i.e., slightly bowed ~r curved. The hone is then rotated to remove material confined in the volume of the broken lines. The results of such practice are shown in Fig. 6ta) which depicts the curved end contact surface contour following such rotation of the hone and ~rior to removal of the same from the housing. As contact finger parts 16a return to their un~lexed conditi~n upon re-moval of the hone, they assume the con~iguration shown in Fig. 6(b).
Upon subsequent insertion of a pin member into the housing, increased - contact surface area exists between the cylindrical outer surface of the pin mem~er and the complementary cur~ed end contact surface ;~ 16g of the honed contact ~inger parts 16a, as shown in Fig. 5.
:
:
, .
:i .. . .
By way of example of a preferred method of fabricatlng a connector having honed louvers, a strip member comprised of beryllium copper alloy 25 of width .687 in. and length 1.078 in.
i9 ~tamped to provide eleven cutouts or openings of the type shown in Fig. 1, the dimensiQns in Figs. 1 and 2 being: r = .031 in.; 11 = .018 in.; 12 = 049 in.; 13 = .098 in.; ~ = .355 in.;
= .049 in.; h2 = .069 in.; and ~ = 55. The strip member is formed into a cylindrically shaped female contact element with the inner strip member diameter being .438 in. The contact ele-ment is next seated in a cylindrical holder of inner diameter .381 in. and a cylindrical diamond hone of outer diameter .310 in., grlt 300, ls inserted in the contact element interior and i9 rotated through four complete revolutions in the direction of in-clination of the radially interior contact finger parts.
Referring to Fig. 7, there i3 shown a further embodi-ment of the invention wherein strip member 10' is a laminated structure including layer lO'c comprised of materiàl, e.g., copper, having relatively low eleatrical re~istance and layer lO'd com-prisea of material, e.~., beryllium, having a relatively high unit i 20 resilience. Contact finger parts 16'a accordingly include a first low electrical resistance layer 16h and a second layer 16i of high - resilience acting as a spring mem~er resiliently engaging ~in mem-ber 22. Where extrem~ty 16'c i3 honed as above discu3sed, a sur-face is defined by portions of each layer. As will be seen in Fig. 7, such surface and layer 16h provide a direct low resistance ; path from the pin member to housing 25.
.
h ~r~
In Flg 8, strip member 10" includes marginal portion~
lO"a and lO"b, each comprised of high unit resillence material as discus~ed above for layer 161, and a central portion lOnc, comprised of low electrlcal reRistance material a~ discussed S a~ove for layer 16h. With thi~ confi~uration, radially interior contact finger part~ have margins functioning as ~prings and an intervening expanse providlng a direct low resistance path from the pin member to the housing.
In instance~ wherein low connector electrical resistance i~ of particular concern, the invention contemplates the coating of the contact fingers with a substance of low resistance, e.g., as by plating or the like.
Various changes may evidently be introduced in the fore-going embodiments wlthout departing from the spirit or ~cope of the invention. By way of example, the strip mem~er is character-ized as elongate in the direction o~ the spacing of openings therein only for purposes of clarity. While the foregoing em-bodiments all treat a female c~ntact element having an interior hollow for receiving a c~mplementary male contact element, the invention of course contemplates the placement of contact finger parts 16a in radially exterior disposition for engagement with a complementary contact element adapted to encircle such parts. Ac-cordingly, the foregoing separately disclosed embodiments are in-tended in an illustrative and not in a limiting sense. The true spirit and scQpe of the invention is set forth in the following claims.
,
Background of the Invention Rnown connectors with contacts having contact fingers in resilient engagement with a complementary contact surface, 30-called "louvered connectors", such as are illustrated in Neidecker U.S. Patent No. 3,453,587 and Crabbs U.S. Patent No. 2,217,433, typically comprise elongate conductive strip members having a plurality of longitudi~al~y spaced transverse openings defining longitudinally and transversely extending expanses therebetween which are bent or twisted with respect to the strip member so as to define contact fingers having opposed ~xtremities displaced from respective opposite ~urfaces of the strip member. It is com-mon to deploy these contacts by havlng the strip member ends dis-, posed in a juxtaposed manner so as to provide a contact element '~ having a substantially circuIar interior into which a male contact in the form of a pin member is insertable. The pin member diameterbeing greater than the diameter of the locus of the radially inter-ior extremities of the contact fingers, the contact fingers are res~liently flexed upon pln member insertion and resiliently engage the same under sufficient contact pressure to provide electrical contact therewith. The strip mem~er finger extremi.ties extend~ng radially exteriorly of ~he strip member engage the walls of a ., .
_ /_ .' ' D
".... . ..
'7 socket seating the contact element whereby an electrlcal path capable of tran ferring current~ of relatively high magnitudes i~
provided between the pin member and the socket.
Performance considerations of presently known connectors and contacts of this type are several in number. Secure engagement of course need be provided between the separable connector parts, ~ i.e., the pin member and the radially interiorly extending contact ;~ finger parts. This consideration necessitates careful control of manufacturing tolerances as between pin member diameter and con-- 10 tact element interior diameter, directly affectlng manufacturing ; C09t3. Secondly, the resistance of the electrical connector to current flow therethrough is dependent to a large degree on sur-face contact area as between the contact fingers and hoth the pin member and the sock~t, engagement of the radially interior contact finger extremities and pin member belng most significant since they are repeatedly separable in connector use. Reliability of this type of connector is also dependent on the cooperation of the contact element and the socket such that the former is not readily removable from the latter, giving rise to manufacturing tolerance control respecting the socket recess provided for containment of the contact element.
Known connectors of this type are not considered to readily exhibit the foregoing performance characteristics to the degree desired. Thus, unduly close manufacturing tolerances are demanded by existing connector structures of this type. Surface area engagement of the ~eparable surfaces is regarded as less than : - 2 -V
adequate for certain applications in which particularly low con-nector electrical resistance is desired. Finally, in the absence of structure, additional to the electically functioning parts of the contact element and socket themselves, for securely seatlng the contact element in the ~ocket, the contact element has been observed to ~e separable from the socket upon manipulatlon of the pin member.
Summary of the Invention It i~ an o~ject of the pre~ent invention to provide impro~ed connectors of the su~ect type, exhibiting improvements over presently-known louvered connectors in each of the perform-ance considerations discussed above.
According to the present invention there is provided an electrical contact adapted to be formed into a cylinder for inter-position between a socket portion of an electrical connector and a . . _ - .
male contact element''~f the electrical connector, said electrical contact comprising a strip of electrically conductive material having a plurality of conductive fingers extending transversely '; across the greater part of the strip and pro~ecting out of the plane thereof, said fingers being integral with said strip and supported thereby for resilient flexure between a normal position and a deflected position, ~aid fingers being adapted to be flexed in use by said male contact element into the deflected position and having a curved end contact surface extending across substantially the entire width of the finger and adapted to engage said male contact element ~aid end contact surface being recessed into said fingers and having a first configuration in the normal position and - a second configuration, different from the first configuration, in the deflected position, said second configuration being complementary to the surface of said male contact element so that said male contact element contacts said end surface ~ubstantially over the . . - - ~
'7~7 whole area thereof.
According to a further aspect of the inventlon there is provided a method of making an el~ctrical contact having re-silient contact flngers engageable with a complementary electrical s contact element including the steps of forming transverse openinga through opposed first and Yecond flat surfaces of an elongated strip member, displaclng outwardly of said strlp member first surface an end portion of each strip member portion between adjacent transverse boundaries of successive such openlngs, forming said strip member ; 10 into a cyl~r with said end portions of said strip m~er portions thereof ex-tending to~d the interior of said cyl ~ er, insertlng into the interior of said cylinder a cylindrical hone of diameter greater than the diameter of the locus d the extremities o~ sald end portions and e~ual to the diameter of said-complementary contact element, and rotating said hone, thereby re-lS moving a part of each said end portion to define a curved end con-tact surface, recessed at the extremity of each said end portion, the fingers being such that upon resilient engagement of the end portions with the electrical contact element the end contact surfaces each change from a first configuration to a second configuration different from the first configuration, the end contact surfaces of said end portions in said second configuration being complement-ary with the surface of said ~ectrical contact element.
The foregoing and other objects and features of the in-vention will be evident from the following detailed description of preferred embodiments thereof as illustrated in the drawings where-in like reference numerals identify like parts throughout.
Brief Description of t~e Drawings Fig. 1 is a plan view of an apertured strip member before expanses between adjacent openings therein are displaced outwardly -30 of the openings to deflne contact fingers.
Fig. 2 is a side elevational view of the strip member of Fig. 1 after expanses between adjacent openings therein are dis-placed outwardly of the openings to define contact flngers.
Fig. 3 is a side elevational view, partly in section and partly broken away to show detail, of a connector employing the strip member of Fig. 2 as a contact between a pin member and a socket.
Fig. 4(a) is a sectional view as seen from the plane IV-IV of Fig. 3.
Fig. 4~b) is a ~ectional ~iewof an alternative embodiment _ ~ _ D
iU~ 7~
of a connector in accordance with the lnventlon.
Fig. 5 is an enlarged partial sectional view of a fur-ther alternative embodiment of a connector in accordance with the invention showing radially inward contact finger parts in engage-,5 ment with a complementary contact surface.
Fig. 6~a) illuQtrates the configuration of the Fig. 5contact finger parts when resiliently ~lexed and Fig. 6tb~ illus-trates ~uch configuration under non-flexed condition.
Fig. 7 is an enlarged partial elevational view of a still further embodiment of a connector in accordance wi~h the invention.
Fig. 8 is a plan view of a further embodiment of the strip member shown in Fig. 1.
Description of the_Preferred Embodiments Referring to Figs. 1 and 2, elongate strip member 10 is comprised of electrically conductive material and includes a series of longitudinally spaced transverse openings 12, 14 extend-ing through opposed first and second surfaces lQa and lOb. Con-sidering the leftwardmost pair of open~ngs, the strip member de-fines a continuous longitudinally and transversely extending ex-panse 16 therebetween, bordered by respectlvely adjacent trans-verse edges or boundaries 12a and 14a of these openings. Expanse~
16 is disposed or displaced angularly outward~ly of these openings, such as by twi~ting, about a transverse axis 18, which axis is located longltudinally closer to one o~ such edges than it is to the other thereof. In the case of axis 18, which i9 longitudinally - closer to edge 12a than to edge 14a, a first part 16a of expanse 16 is disposed, as shown in Fig. 2, at an acute angle ~ relative to strip member surface lOa and a second part 16b of expanse 16 is disposed at an acute angle ~ relative to strip member surface lOb, with first part 16a b~eing of greater longitudinal extent than second part 16b. Upon such twisting of expanse 16, the same defines a contact finger or louver.
So prepared, the strip member then is formed into a cylindrical or ring-like shape with contact finger parts 16a extending radlally inward ~f such cylinder and contact fingers parts 16b extending radially outward of the cylinder, as shown in Figs.
' .
r~
i(~tilt~77 3 and 4ta). This arrangement provides a female contact element 20 which, when seated ln socket 24 of housing 25, as depicted in Fig. 3, reslliently engage~ the encircling housing wall through - extremlties 16d of finger parts 16b, and i9 adapted for receiving a male contact element in the ~orm of a cylindrically-shaped pin member 22, which latter will be resiliently engaged by sharp con-tact edges 16Cl of each of extremities 16c of finger parts 16a.
A recess 26 is provided in socket 24 for seating contact element 20 and retalning it against withdrawal. The housing socket dia-meter is slightly greater than the pin member outer diameter, withthe latter greater than the locus of extremities 16c of the con-tact fingers when the pin member is not receivably engaged within the female contact element 20 in housing socket 24. The contact fingers accordingly provide electrical connection between the pin member and the housing when the pin member is received within the housing soc~et substantially as shown in Figs. 3 and 4(a~.
Various advantages attend the asymmetrical longitudinal relation existing among the twist axis and the respectively adjac-ent edges of successive ~trip member openings. In one aspect, the radially interior contact finger parts 16a encompass a major extent of the combined parts 16a and 16b of the contact fingers. Parts 16a thus constitute radially interior spring elements of greater longitudinal extent than those of the above-referenced known louvered connectors, which are derived from twisting of the strip member expanse about a transverse axis symmetrically disposed relative to respectively ad~acent transverse edges of successive strip member openings. Since spring rate, i.e., the ratio of load - 6 -`
Y
: . .
lU~ 7 to spring deflection, i~ lnversely proportlonal to spring longi-tudinal extent, thls geometry o~ the invention provides for lower spring rate for the interior contact finger part than in known louvered connectors (the ~pring material, its thickness and it~
S width being the same). As a recult, lt has been found that re-silient engagement of contact fingers of connectors constructed - in accordance with the invention providing desired electrical contact occurs for pin members varying over a greater range in diameter than is the case for otherwise like pri0r louvered con-nector~. Manufacturing tolerances as between the locus of the extremlties of interior contact finger parts and pin diameter i~
thereby relaxed, giving rise to lowered costs in manufacture.
Apart from this advantage attending increased longi-tudinal extent of radially interior contact finger parts, further advantage attendq the conse~uent reduction in length of radially exterior contact finger parts. With yart 16b having longitud~nal extent reduced as compared to like elements in the symmetrical twist axis case of known ?ouvered connectors, the radial depth of the housing recess seating the ctrip member may be lessened, giving rise to reduced manufacturlng cost. Alternatively, for the same radial recess depth as in known louvered connectors, strip members of the invention are seated more deeply therein and hence are les~ su3ceptible to remcval on manipulation of the pin member.
The asymmetry in contact finger parts may be attained and the foregoing advantages realized without need for displacing :, i ;'7 the entirety of expan~e 16 outwardly of the strip member openings.
Thus, contact flnger part3 16a and 16b may comprise opposed end portions of such strip member expanse displaced outwardly of the strip member openings, with one such end portion being of greater S longitudinal extent than the other. The strip member is then formed into cylindricaI shape as discussed above, such that the radially interior end portions are of greater longitudinal extent than the radially exterior end portions. In the particularly preferred embodiment, however, the sum of the longitudinal extent~
of the respective opposed end portions of each contact finger equals the longitudlnal extent of the strip member c~ntinuous expanse defining such contact flnger.
Referring now to the c~nnector embodiment of Fig. 4(b), the contact fingers are formed by asymmetrical twisting but are disposed at an angle less than angle ~ of Fig. 2, whereby contact ., .
finger parts 16a are ln other than sharp contact edge engagement ~ with pin member 22. That is, in the embodiment of Fig. 4(b), con-tact is achieved by resilient engagement between elongate flat i~ surface 16e of each contact finger and the surface of the cylin-` 20 drical pin mem~er. Such Fig. 4~b) arrangement provides surface area contact between parts 16a and pin member 22 increased over that obtainlng in endwise engagement, such as the sharp contact edge engagement de9cribed in Flg. 4~a) above. In accordance with `- another aspect of the invention, the contact finger extremities may be prepared as now discussed in connection with Figs. 5, 6(a) and 6(b).
. .
10~ 77 As shown in Figs. 5 and 6(b), each contact finger part 16a includes opposed elongate flat surfaces 16e, 16f extending to the extremity 16c thereof displaced from strip member surface lOa. At extremity 16c, a surved end contact surface 16g extends from at least one of surfaces 16e and 16f, for example, it ex-tends from surface 16e as shown, toward the other surface 16f.
At extremity 16c, a flat end surface is provided in a plane other than, and preferably in a plane orthogonal to, the planes of elongate flat surfaces 16e and 16f. Curved end contact surface 16g intersects such extremity flat end surface over substantially the entire transverse extent of the extremity thereof, the inter-section between curved end contact surface 16g and the flat end surface defining a curved common boundary 16C2 for such flat end surface and curved end contact surface 16g. It will be noted that the curvature of such common boundary 16C2 occurs entirely within the plane defined by the flat end surface of extremity 16c. ~-Such curved end contact surface 16g may be located other than at extremity 16c, e.g., in the case where contact is to be made as in Fig. 4(b) the surface 16g may be included as a : portion of the elongate flat surface 16e at a position displaced from the flat end surface of extremity 16c.
; In forming surface 16g, material is removed from extrem-ity 16c, when the finger is in its flexed condition as shown in Fig. 6(a), until the curved end contact surface 16g is defined.
The broken line outline in Fig. 6(a) indicates the original con-; figuration of the finger prior to the removal of such material ' when the finger is in the flexed condition, whereas the broken ;~
line outline in Fig. 6(b) indicates the original configuration of the finger prior to the removal of such material and when the -finger is in its unflexed condition.
_ g _ ~, . .
'7 Preferably, this materlal remo~al i9 effected by forming the strip member into contact element 20 as in Flgs.
1-4, seating the same in housing 25 and lnserting a hone in the shape and size ~particularly outer diameter) of pin member 22 into the contact element interlor, thus causing the contact finger parts to flex inbo resllient engagement with the hone outer surface. Under such loading each contact ~inger part assumes the configuration shown in Flg. 6ta), i.e., slightly bowed ~r curved. The hone is then rotated to remove material confined in the volume of the broken lines. The results of such practice are shown in Fig. 6ta) which depicts the curved end contact surface contour following such rotation of the hone and ~rior to removal of the same from the housing. As contact finger parts 16a return to their un~lexed conditi~n upon re-moval of the hone, they assume the con~iguration shown in Fig. 6(b).
Upon subsequent insertion of a pin member into the housing, increased - contact surface area exists between the cylindrical outer surface of the pin mem~er and the complementary cur~ed end contact surface ;~ 16g of the honed contact ~inger parts 16a, as shown in Fig. 5.
:
:
, .
:i .. . .
By way of example of a preferred method of fabricatlng a connector having honed louvers, a strip member comprised of beryllium copper alloy 25 of width .687 in. and length 1.078 in.
i9 ~tamped to provide eleven cutouts or openings of the type shown in Fig. 1, the dimensiQns in Figs. 1 and 2 being: r = .031 in.; 11 = .018 in.; 12 = 049 in.; 13 = .098 in.; ~ = .355 in.;
= .049 in.; h2 = .069 in.; and ~ = 55. The strip member is formed into a cylindrically shaped female contact element with the inner strip member diameter being .438 in. The contact ele-ment is next seated in a cylindrical holder of inner diameter .381 in. and a cylindrical diamond hone of outer diameter .310 in., grlt 300, ls inserted in the contact element interior and i9 rotated through four complete revolutions in the direction of in-clination of the radially interior contact finger parts.
Referring to Fig. 7, there i3 shown a further embodi-ment of the invention wherein strip member 10' is a laminated structure including layer lO'c comprised of materiàl, e.g., copper, having relatively low eleatrical re~istance and layer lO'd com-prisea of material, e.~., beryllium, having a relatively high unit i 20 resilience. Contact finger parts 16'a accordingly include a first low electrical resistance layer 16h and a second layer 16i of high - resilience acting as a spring mem~er resiliently engaging ~in mem-ber 22. Where extrem~ty 16'c i3 honed as above discu3sed, a sur-face is defined by portions of each layer. As will be seen in Fig. 7, such surface and layer 16h provide a direct low resistance ; path from the pin member to housing 25.
.
h ~r~
In Flg 8, strip member 10" includes marginal portion~
lO"a and lO"b, each comprised of high unit resillence material as discus~ed above for layer 161, and a central portion lOnc, comprised of low electrlcal reRistance material a~ discussed S a~ove for layer 16h. With thi~ confi~uration, radially interior contact finger part~ have margins functioning as ~prings and an intervening expanse providlng a direct low resistance path from the pin member to the housing.
In instance~ wherein low connector electrical resistance i~ of particular concern, the invention contemplates the coating of the contact fingers with a substance of low resistance, e.g., as by plating or the like.
Various changes may evidently be introduced in the fore-going embodiments wlthout departing from the spirit or ~cope of the invention. By way of example, the strip mem~er is character-ized as elongate in the direction o~ the spacing of openings therein only for purposes of clarity. While the foregoing em-bodiments all treat a female c~ntact element having an interior hollow for receiving a c~mplementary male contact element, the invention of course contemplates the placement of contact finger parts 16a in radially exterior disposition for engagement with a complementary contact element adapted to encircle such parts. Ac-cordingly, the foregoing separately disclosed embodiments are in-tended in an illustrative and not in a limiting sense. The true spirit and scQpe of the invention is set forth in the following claims.
,
Claims (8)
1. An electrical contact adapted to be formed into a cylinder for interposition between a socket portion of an electrical connector and a male contact element of the elec-trical connector, said electrical contact comprising a strip of electrically conductive material having a plurality of conductive fingers extending transversely across the greater part of the strip and projecting out of the plane thereof, said fingers being integral with said strip and supported thereby for resilient flexure between a normal position and a deflected position, said fingers being adapted to be flexed in use by said male contact element into the deflected position and having a curved end contact surface extending across substantially the entire width of the finger and adapted to engage said male contact element said end contact surface being recessed into said fingers and having a first configuration in the normal position and a second configuration, different from the first configuration., in the deflected position, said second con-figuration being complementary to the surface of said male contact element so that said male contact elements contacts said end surface substantially over the whole area thereof.
2. An electrical contact as claimed in claim 1, wherein said contact is formed into said cylinder and adapted to seat within a recess in the socket portion with said fingers resil-iently engaging the wall of said recess.
3. An electrical contact as claimed in claim 2, wherein said fingers are in the form of louvers extending from both sides of a strip of conducting material whereby each finger has a first extremity on an outwardly directed louver portion for engagement with the wall of the recess to provide an electrical connection therewith, and a second extremity containing said end contact surface an an unwardly directed louver portion to contact said male contact elements upon insertion into said socket portion.
4. An electrical contact as claimed in Claim 3, wherein the male contact element is a pin member of diameter less than the diameter of said socket portion and greater than the diameter of the locus of said contact finger second extremities, said contact fingers being arranged resiliently to engage said pin member upon insertion of said male contact element in said socket portion whereby said strip provides electrical connection between said socket portion and said male contact.
5. An electrical contact as claimed in Claim 4, wherein each said contact finger includes opposed elongate flat sur-faces extending to said contact finger second extremity and said curved end contact surface extends at said second extremity from one of said contact finger elongate flat surfaces toward the other thereof.
6. An electrical contact as claimed in claim 1, wherein the conductive fingers are each inclined with respect to the strip of conductive material, wherein each finger has a first portion projecting from one surface of the main strip portion and a second portion projecting from the opposite sur-face of said main strip portion, said first finger portion having a greater projecting length than said second finger por-tion, and wherein each said first finger portion includes opposed elongated flat surfaces extending to the finger extremity displaced from said strip portion and wherein said curved end con-tact surface extends at said extremity from one of said elongated flat surfaces toward the other.
7. An electrical contact as claimed in claim 6, wherein said finger extremity displaced from said strip includes a flat end surface disposed in a plane other than the planes of said elongated flat surfaces of said contact finger.
8. A method of making an electrical contact having resilient contact fingers engageable with a complementary elec-trical contact element including the steps of forming transverse openings through opposed first and second flat surfaces of an elongated strip member, displacing outwardly of said strip mem-ber first surface an end portion of each strip member portion between adjacent transverse boundaries of successive such openings, forming said strip member into a cylinder with said end portions of said strip member portions thereof extending toward the interior of said cylinder, inserting into the inter-ior of said cylinder a cylindrical hone of diameter greater than the diameter of the locus of the extremities of said end por-tions and equal to the diameter of said complementary contact element, and rotating said hone, thereby removing a part of each said end portion to define a curved end contact surface, recessed at the extremity of each said end portion, the fingers being such that upon resilient engagement of the end portions with the electrical contact element the end contact surfaces each change from a first configuration to a second configuration different from the first configuration, the end contact surfaces of said end portions in said second configuration being comple-mentary with the surface of said electrical contact element.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US50378374A | 1974-09-06 | 1974-09-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1061877A true CA1061877A (en) | 1979-09-04 |
Family
ID=24003490
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA234,864A Expired CA1061877A (en) | 1974-09-06 | 1975-09-05 | Louvered connectors and contact elements thereof |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5166477A (en) |
| AU (1) | AU502197B2 (en) |
| BE (1) | BE833093A (en) |
| CA (1) | CA1061877A (en) |
| CH (2) | CH614566A5 (en) |
| DE (1) | DE2539675C2 (en) |
| FR (1) | FR2284203A1 (en) |
| GB (1) | GB1528481A (en) |
| SE (2) | SE412300B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4191445A (en) * | 1976-01-16 | 1980-03-04 | Multilam Corporation | Louvered electrical connector |
| CH650108A5 (en) * | 1980-03-13 | 1985-06-28 | Sotax Ag | CONTACT ORGAN. |
| JPH0528952Y2 (en) * | 1986-10-16 | 1993-07-26 | ||
| DE3808632C1 (en) * | 1988-03-15 | 1989-10-12 | Georg Dr.-Ing. 8152 Feldkirchen-Westerham De Spinner | |
| DE8806594U1 (en) * | 1988-05-19 | 1989-01-05 | Schaltbau Gmbh, 8000 Muenchen, De | |
| DE3923474C2 (en) * | 1989-07-15 | 2000-05-04 | Leybold Ag | Electrical switch |
| EP0665566B1 (en) * | 1994-02-01 | 1999-08-11 | Bayerische Motoren Werke Aktiengesellschaft, Patentabteilung AJ-3 | Electric safety switch for motor vehicles |
| DE19606447A1 (en) * | 1996-02-21 | 1997-08-28 | Bayerische Motoren Werke Ag | Circuit breaker for a battery cable in vehicles |
| DE19610178A1 (en) * | 1996-03-15 | 1997-09-18 | Abb Patent Gmbh | Electrical contact breaker-connector and earthing system e.g. for HV gas-insulated switchgear |
| JP3412738B2 (en) * | 1996-10-11 | 2003-06-03 | 矢崎総業株式会社 | Method of forming female terminal for large current |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2217433A (en) * | 1937-02-20 | 1940-10-08 | Westinghouse Electric & Mfg Co | Electrical device |
-
1975
- 1975-08-29 GB GB35803/75A patent/GB1528481A/en not_active Expired
- 1975-09-03 SE SE7509765A patent/SE412300B/en not_active IP Right Cessation
- 1975-09-04 DE DE2539675A patent/DE2539675C2/en not_active Expired
- 1975-09-05 CA CA234,864A patent/CA1061877A/en not_active Expired
- 1975-09-05 CH CH660578A patent/CH614566A5/en not_active IP Right Cessation
- 1975-09-05 FR FR7527341A patent/FR2284203A1/en active Granted
- 1975-09-05 CH CH1152675A patent/CH614567A5/en not_active IP Right Cessation
- 1975-09-05 AU AU84588/75A patent/AU502197B2/en not_active Expired
- 1975-09-05 BE BE1006865A patent/BE833093A/en not_active IP Right Cessation
- 1975-09-06 JP JP50108449A patent/JPS5166477A/en active Granted
-
1978
- 1978-06-20 SE SE7807032A patent/SE431701B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| AU8458875A (en) | 1977-03-10 |
| JPS6132785B2 (en) | 1986-07-29 |
| BE833093A (en) | 1976-03-05 |
| DE2539675C2 (en) | 1983-04-28 |
| SE431701B (en) | 1984-02-20 |
| JPS5166477A (en) | 1976-06-09 |
| SE7509765L (en) | 1976-03-08 |
| FR2284203B1 (en) | 1981-03-06 |
| AU502197B2 (en) | 1979-07-19 |
| FR2284203A1 (en) | 1976-04-02 |
| CH614567A5 (en) | 1979-11-30 |
| SE412300B (en) | 1980-02-25 |
| SE7807032L (en) | 1978-06-20 |
| DE2539675A1 (en) | 1976-03-18 |
| GB1528481A (en) | 1978-10-11 |
| CH614566A5 (en) | 1979-11-30 |
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