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Publication numberUS3605072 A
Publication typeGrant
Publication dateSep 14, 1971
Filing dateFeb 28, 1969
Priority dateFeb 28, 1969
Also published asDE2010436A1, DE2010436B2
Publication numberUS 3605072 A, US 3605072A, US-A-3605072, US3605072 A, US3605072A
InventorsDriscoll Aelred Daniel
Original AssigneeMinnesota Mining & Mfg
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Solderless wire connector
US 3605072 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Inventor Aelred Daniel Driscoll North St. Paul. Minn.

Appl. No. 803,235

Filed Feb. 28, 1969 Patented Sept. 14, 1971 Assignee Minnesota Mining and Manufacturing Company St. Paul, Minn.


U.S. Cl 339/98 Int. Cl H01r 11/20 Field of Search 339/97-99 [56] References Cited UNITED STATES PATENTS 3,027,536 3/l962 Pasternak 339/97 3,234,498 2/1966 Logan 339/97 P 3,258,733 6/1966 Elm 339/98 3,403,372 9/1968 Stinson, Jr. 339/97 Primary Examiner-Stephen J. Novosad Assistant Examiner-Joseph H. McGlynn Attorney-Kinney, Alexander, Sell, Steldt & Delahunt ABSTRACT: A solderless wire connector comprising a thin resilient flat plate contact element with parallel extended legs fitting into a grooved wire-supporting base and defining openended wire-receiving slots, wherein said legs are internally perforated to provide stress relief along wire-contacting edges.


M/ /zy FIG. I

FIG. 4

INVIENTOK AEL RED DAN/EL DR/SCOLL MWKOQLOGIM ATTORNEYS SOLDERLESS WIRE CONNECTOR This invention relates to solderless wire connectors for making electrical connections to insulated wires. The contact element consists essentially of a thin resilient flat metal plate having parallel extended legs defining open-ended wire-receiving slots. Connectors of this type have previously been described, for example in Levin et al. U.S. Pat. No. 3,012,219 and in Elm U.S. Pat. Nos. 3,258,733 and 3,388,370. They provide excellent electrical contact with insulated wires of appropriate diameter but require surprisingly high application forces, particularly for larger wire sizes or for simultaneous connection to a number of wires.

The present invention makes possible a significant reduction in the force required for insertion of the wires, and at the same time improves the wire-retaining ability of connectors of the type described. As a result, connection to wires of relatively large diameter, or to flat cables containing many parallel smaller wires, is facilitated. Connectors made in accordance with the invention are found to be particularly effective on aluminum wires, which normally tend to undergo cold flow deformation under continued severe stress.

These and other advantages are obtained by providing means for relieving a portion of the stress applied along the edges for the extended legs of the contact element. In a preferred embodiment, some or all of the extended legs are perforated to provide an open interior stress-relief area. The remaining edge strips are thus enabled to be resiliently deformed as the element is forced onto a wire, thereby reducing the degree of resilient deformation required in the area of the plate connecting the two wire-contacting legs. The slight deformation at the contacting edge results in an increase in the ability of the connector to retain the wire against forces tending to loosen or remove the same.

Illustrative embodiments of the invention will now be further described in connection with the appended drawing, wherein FIG. 1 is a front elevation, and FIG. 2 a side elevation, of a portion of a connector shown partly in section and as applied to two insulated wires, and

FIGS. 3-5 are front elevations showing alternative contact member configurations. l

The connector of FIGS. 1 and 2 will be seen to comprise a base 11 and a contact element 12 having narrow outer legs 19, 20 and a wider centrally perforated central leg 21. Wires 13, consisting of copper conductor 14 and insulating covering 15, are supported on wire-supporting surfaces 16 of the base 11 and lie across a narrow groove 18 designed to receive the element 12, the wires being supported in alignment with the open-ended slots defined by adjacent legs of the contact element. Forcing the element 12 into the grooved base forces the wires into the slots and causes resilient spreading of the outer legs 19, 20. The slot-defining edges of the legs displace the insulation and make electrically conductive contact with the wire 14. The width of the inner leg is greater than that of the outer legs in these contact elements to provide space for the thickness of insulation on the wires.

The central leg 21 of contact member 12 is longitudinally perforated at perforation 24, as shown in FIG. 1, leaving two narrow terminally interconnected edge strips 22, 23. Under the forces imparted on entry of the wire 14, these strips are resiliently bowed inwardly, thereby decreasing the force required to make the connection and at the same time providing a more secure grip on the wire than would be possible without the stress-relief opening.

FIG. 3 illustrates an alternative contact element 32 wherein the outer legs 29, 30 as well as the inner leg 31 are perforated, thereby still further reducing the force required to effect the contact and also further improving the angle of contact.

The elongated contact element42 of FIG. 4 is capable of making effective contact with more than one wire in each open-ended slot. The narrow edge strips of the several legs of the element maintain substantially equal pressure against each of the wires inserted, so that good contact is provided with each wire.

FIG. 5 illustrates another variation wherein the central leg 51 of the contact element 52 is provided with a generally diamond-shaped perforation whereas the outer legs 49, 50 each have a circular perforation in line with the widest portion of the diamond, thereby providing a centering action to position the wires between the legs of the contact element.

It will be appreciated that the same principles may be applied to connectors wherein the contact element may have two, three, or any larger number of legs defining any desired number of wire-receiving open-ended slots, and with various specific configurations or combinations of perforations forming stress-relief openings in some or all of said legs.

In a specific illustrative but nonlimiting example of a connector as shown in FIGS. 1 and 2 and designed for connecting together two No. 10 plastic insulated copper wires, the contact element 12 is made of 35 mil tin-plated spring-temper brass plate. The overall dimensions are 0.4l5 0.365 inch. The length of the center leg is 0.230 inch. The stress-relief opening in the center leg is 0.062 inch wide and 0.217 inch long, the edge strips therefore being 0.038 inch in width. As compared with an otherwise identical contact element but having no stress-relief opening, the wire insertion force is reduced by about one-tenth, while the force required to remove the element from the wires is increased by about the same amount. After 2,000 cycles on a test rack, each cycle representing 45 minutes on voltage followed by connector is measurably less than that at the conventional connector.

What is claimed is as follows:

1. A contact member for a solderless connector, comprising a thin resilient flat plate having at least one pair of parallel extended legs defining an open-ended wire-receiving slot, at lest one of said legs having a perforation laterally spaced from the wire-receiving slot for partial relief of stress at the wire-contacting edge during forceful insertion of a wire into said wirereceiving slot.

2. The contact member of claim 1 having three extended legs defining two wire-receiving slots and wherein the central leg is perforated for stress relief.

3. The contact member of claim 1 wherein each of said legs is perforated for stress relief.

4. The contact member of claim 1 wherein said legs extend a distance sufficient to permit insertion of at least two wires into said wire-receiving slot.

5. A wire connector comprising the contact member of claim 1 cooperatively associated with a transversely grooved base having a wire-supporting surface, said contact member being disposed for entry of said legs into said groove and with said wire-receiving slot in line with said wire-supporting surface.


Inventor) Aelred Daniel Driscoll It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 3 following by insert 15 minutes off voltage, the resistance at the stress relief Column 2, line ML, after "at" delete lest and insert --least--- Signed and sealed this ll th day of March 1972.

(SEAL) Attest:

EDWARD M.FLETCHE1R, JR. ROBERT GOTISCHALK Attesting; Officer Commissioner of Patents )RM PO-1050 (10-6 USCOMM-DC 6037G-P69 Q U 5 GOVERNMENT HUNTING OFFDCE I969 0-356-33l

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3027536 *Dec 5, 1958Mar 27, 1962Bell Telephone Labor IncInsulation stripping wire connector
US3234498 *Jun 4, 1963Feb 8, 1966Western Electric CoInsulation-penetrating clip-type electrical connectors
US3258733 *Apr 8, 1963Jun 28, 1966 Wire connector
US3403372 *Feb 3, 1966Sep 24, 1968Herman B. Stinson Jr.Method of making electrical connections and the connections produced thereby
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3703700 *Mar 17, 1971Nov 21, 1972Ericsson Telefon Ab L MTerminal block for slot connection of insulated conductors
US3748462 *Mar 2, 1972Jul 24, 1973Grote Mfg CoCombination vehicle lamp and junction box
US3869190 *Mar 29, 1974Mar 4, 1975Minnesota Mining & MfgSolderless wire connector
US3949467 *Jun 26, 1975Apr 13, 1976Minnesota Mining And Manufacturing CompanySolderless electrical connector element application method and apparatus
US3950062 *Jul 23, 1974Apr 13, 1976Amp IncorporatedWire slot terminal double beam system
US4037905 *Dec 12, 1975Jul 26, 1977Ideal Industries, Inc.No-strip electrical connector
US4085994 *Aug 12, 1976Apr 25, 1978Amp, IncorporatedDual slot contact
US4116522 *Dec 2, 1977Sep 26, 1978Amp IncorporatedSlotted terminal
US4452501 *Apr 30, 1982Jun 5, 1984General Motors CorporationElectrical connector with latch terminal
US4891018 *Jun 16, 1988Jan 2, 1990Minnesota Mining And Manufacturing CompanySolderless electrical connector
US4954098 *Nov 1, 1989Sep 4, 1990Minnesota Mining And Manufacturing CompanySealed insulation displacement connector
US5080606 *Nov 5, 1990Jan 14, 1992Minnesota Mining And Manufacturing CompanyStacked in-line insulation displacement connector
US5423694 *Apr 12, 1993Jun 13, 1995Raychem CorporationTelecommunications terminal block
US5557250 *Apr 12, 1993Sep 17, 1996Raychem CorporationTelecommunications terminal block
US5588869 *May 1, 1995Dec 31, 1996Raychem CorporationTelecommunications terminal block
US5742223 *Dec 7, 1995Apr 21, 1998Raychem CorporationLaminar non-linear device with magnetically aligned particles
US6093050 *Apr 3, 1998Jul 25, 2000Baum; Thomas MatthewTelecommunications terminal block
US6302723Jul 24, 2000Oct 16, 2001Tyco Electronics CorporationTelecommunications terminal block
US6730083 *May 7, 2002May 4, 2004B. Braun Melsungen AgPuncture cannula
US9172152 *May 21, 2013Oct 27, 2015Omron CorporationPressure welding terminal
US20020198557 *May 7, 2002Dec 26, 2002Helmut FreigangPuncture cannula
US20130323988 *May 21, 2013Dec 5, 2013Omron CorporationPressure welding terminal
DE102012101071A1 *Feb 9, 2012Aug 14, 2013Phoenix Contact Gmbh & Co. KgInsulation displacement contact for contacting with insulating material surrounded conductor, has first cutting arm and second cutting arm whose longitudinal side surfaces are provided with through-holes
EP0248902A1 *Dec 19, 1986Dec 16, 1987Amp IncOptical fiber connector.
EP0248902A4 *Dec 19, 1986Feb 5, 1990Amp IncOptical fiber connector.
U.S. Classification439/402
International ClassificationH01R4/24
Cooperative ClassificationH01R4/2429
European ClassificationH01R4/24B3C1