US3790918A

US3790918A - Electrical connector

Info

Publication number: US3790918A
Application number: US00219711A
Authority: US
Inventors: W Dauser
Original assignee: HENEVELD L DAUSER TRUST
Current assignee: HENEVELD L DAUSER TRUST
Priority date: 1972-01-21
Filing date: 1972-01-21
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05

Abstract

An insulation stripping, solderless electrical connector formed of a twisted length of wire-like resilient material having the lower U shaped portion forming a conductor-engaging pressure junction to securely hold the conductor therein. In one of its embodiments, the connector includes exposed twisted, sharpened portions at the upper or entrance portion which cut and clean the insulation from a conductor. In another embodiment of the invention, the entrance portion or channel is provided with facing serrated edges to clean and strip the insulation from the conductor.

Description

United States Patent [191 Dauser '[4 1 Feb. 5, 1974 1 ELECTRICAL CONNECTOR [75] Inventor: William C. Dauser, North Muskegon, Mich.

[22] Filed: Jan. 21, 1972 [21] Appl. No.: 219,711

[52] US. Cl 339/97 R [51] Int. Cl H01! 9/08 [58] Field of Search 339/95, 97-99 [56] References Cited UNITED STATES PATENTS 3,234,498 2/1966 Logan... 339/97 P 3,227,991 1/1966 Zdanis 339/98 3,147,058 9/1964 Zdanis 339/97 R 2,716,247 8/1955 Poupitch 151/35 3,594,712 7/1971 Enright et a1. 339/97 R 3,605,071 9/1971 Sedlacek 339/97 P FOREIGN PATENTS OR APPLICATIONS 1,963,313 6/1971 Germany 339/97 R Primary Examiner-Joseph H. McGlynn Attorney, Agent, or Firm-Price, l-leneveld, l-luizenga & Cooper [5 7] ABSTRACT provided with facing serrated edges to clean and strip the insulation from the conductor.

15 Claims, 10 Drawing; Figures 1 ELECTRICAL CONNECTOR BACKGROUND OF THE INVENTION This invention relates to electrical connectors and more particularly to an insulation stripping, solderless connector, and is an improvement over my U.S. Pat. No. 3,478,303, issued Nov. 1 1, 1969, entitled ELEC- TRICAL CONNECTOR."

In many types of electrical installations, the soldering of individual leads to terminal posts, clips, and similar connectors isnot practical. If, for example, the installation is relatively temporary, the time required to solder each connection is not justified, and the relative permanence of the finished installation would seriously detract from the reusability of the components. If the particular installation is one which often necessitates servicing, the constant resoldering of the connection is likely to result in faulty performance as well as loss of operating time. In addition, in the construction of many electronic devices, for example television sets, telephone relay terminal systems, radios and the like, the various circuit components must be innerconnected by point-to-point wiring using an insulated conductor. In the volume production of this type of product, the insulated wires are generally cut to length, the insulating material is removed for a specified distance from each end, and the exposed conductor material is tinned. The wire is then wrapped around the terminal block, post or other component mounting arrangement and is soldered'in place.

A number of different types of solderless connectors have been proposed in the past to eliminate some of this effort. Some connectors have been proposed which by means of brute force will mash the insulating material from around the conductor as it is drawn between a pair of U shaped legs which are squeezed together by a pair of pliers thereby displacing the insulated covermg.

While connectors of this type may be satisfactory for some applications, quite often in critical applications a high resistance connection results. In addition, these connectors have not generally been operative to clean oxides, dirt, or the like from the lead or conductor when the two components are joined. These factors, of course, promogate poor circuit performance and reliability.

It is, therefore, an object of the present invention to provide an improved solderless connector not subject to the above-outlined disadvantages.

More particularly, it is an important object of the present invention to provide a connector which will cut the insulation to expose a conductor as it is drawn into the connector.

It is another object of the invention to provide a wire connector which may be rapidly and easily applied to a bare or insulated wire to form a low resistance connection therewith.

Still another important object of the present invention isthe provision of a connector which is simple and economical to manufacture.

These, as well as other objects of this invention, will be readily understood by reference to the following specification and accompanying figures in which:

FIG. 1 is a plan view of the invention;

FIG. 2 is a cross-sectional view taken along the plane II--II of FIG. 1;

FIG. 3 is a cross-sectional view taken along the plane III-III of FIG. 1;

FIGS. 4A through 4D are a series of plan views illustrating the operation of the stripping mechanism and connector as a conductor is inserted therein;

FIG. 5 is a plan view of alternate embodiment of the invention;

FIG. 6 is a cross-sectional view taken along the plane VIVI of FIG. 5;

FIG. 7 is a cross-sectional view taken along the plane VIIVII of FIG. 5;

FIG. 8 is a perspective view of a multiple connector constructed in accordance with the invention;

FIG. 9 is a perspective view of a double connector constructed in accordance with the invention and adapted for encasement in an insulating housing; and

FIGS. 10A through 10D illustrate in schematic form the installation of an insulated conductor into the connector assembly of FIG. 9.

SUMMARY OF THE INVENTION Briefly, this invention comprises an electrical circuit connector adapted to conductively engage a conductor and which, as the conductor is being placed therein automatically removes the insulating material from the conductor to insure a positive electrical connection. The connector is a generally bifurcated U shape having a pair of upstanding legs forming an entrance and insulating stripping channel and forms a conductor holding section at the bottom thereof. In one embodiment of the invention, a portion of each arm is twisted at least one full turn thereby providing a plurality of cutting edges on each arm. These edges serve to cut the insulation from the wire as it is drawn therebetween. In another embodiment, the channel forming the opening entrance to the conductor holding section has facing sides provided with a serrated section along at least a part of its length to form an insulation stripping mechanism.

In another of its embodiments, the connector or a plurality of connectors may be embedded in a resilient, plastic, insulating material to form. a convenient, readily attachable insulated connector.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the figures, a preferred embodiment of the invention will be described in detail. F IGS. 1 through 3 illustrate a first embodiment of the novel connector generally designated by the numeral 10. The connector is comprised basically of three functional sections generally formed in a U shape, an entrance opening 12, an insulation stripping channel 14, and a conductor engaging section 16. Preferably, the connector is formed of square resilient stock such as music wire. The radius of curvature 22 at the lower portion of the conductor engaging section 16 is slightly smaller than the smallest conductor to be engaged to prevent any tendency for the conductor to pull free from the engaging section 16. 1

The entrance opening 12 is formed to provide an opening slightly larger than the outer diameter of the conductor and its insulating material. The faces of the entrance opening 18 and 20 extend outwardly at the top, taper downwardly and slightly inwardly at 24 and 26 toward the center to form an entrance to the .insulation stripping channel 14.

The stripping channel is formed of a pair of

adjoining legs

18 and 20. A portion of each leg is rotated or twisted at least one full turn. One arm is preferably twisted clockwise and the other arm is twisted counterclockwise as shown in FIG. 2. This twisting provides, at the inwardly facing corners, a plurality of cutting edges 30 at several points along the length of each leg. Actually, as the material is twisted, the metal is stressed and tends to flow toward the corners forming slightly concave side surfaces 31.

At the lower end of the stripping channel 14, the faces 18 and and cutting edges 30 touch at the center and form an entrance opening 38 to the conductor engaging section 16. As the

faces

18 and 20 continue downwardly, they present a flat planar surface 19 and 21 (FIG. 3) and taper slightly outwardly in the conductor engaging section 16 to form the previously described radius of curvature 22 at the bottom.

As previously noted, the connector is preferably formed from a square resilient stock. When providing a connector for an 18-gauge wire, for example, the connector may be fabricated from .040 annealed music or spring steel wire. Of course, many other materials are available as will be readily appreciated by those skilled in the art. After the connector has been fabricated, it is preferably spring tempered and then coated or tinned with a relatively inert material having good conductive properties. The tinning serves two primary functions. It improves the conductive properties of the connector, and it prevents oxidation of the material.

The particular dimensions of the connector will depend, of course, upon the range of conductor sizes it must accommodate and the electrical environment in which it is to be utilized. As pointed out previously, the radius of curvature 22 should be less than the crosssectional measurement of the smallest conductor with which the connector is to be utilized. It will ordinarily be necessary therefore to provide a number of different sizes of connectors to accommodate varying sizes of conductors.

OPERATION apart-allowing the entrance of the conductor and the .insulation into the stripping channel 14. As the insulated conductor is drawn downwardly as shown in FIG. 4C, the insulation is cut by the sharp comers 31 and spread apart along the wire. The connector, because of its resilient construction, begins to close toward the conductor. In FIG. 4D, the conductor has reached the bottom tapered surface of the stripping channel, and the connector begins to close at 38. As the conductor is pulled through section 38 and enters the conductorengaging sections 16, the

legs

18 and 20 are spread apart by the conductor and the parallel, planer faces 19 and 21 remove the last traces of insulation, dirt, or oxides from the wire. Spring tension of the connector on the conductor begins to slightly flatten the conductor as it moves downwardly. As the conductor is pulled completely down into the conductor-engaging section 16, 'the opening at 38 will close together or attempt to close, and the conductor is securely held between the

faces

19 and 21 within the conductor engaging section 16. Additional conductors may then be pulled through the connector and the cutting mechanism in the fashion as just described providing an effective electrical connector for one or a plurality of conductors.

A modified form of the connector is illustrated in FIGS. 5 through 7 wherein like reference numerals bearing the prime designation are utilized to designate like parts. The embodiment of FIG. 5 generally designated by the numeral 10 is comprised basically of three functional sections generally formed in a U shapean entrance opening 12', an insulation stripping channel 14', and a conductor-engaging section 16'. As in the embodiment shown in FIG. 1, the connector is formed of square resilient stock such as music wire. The radius of curvature 22' at the lower portion of the conductor-engaging section 16' is slightly smaller than the size of the'smallest conductor to be engaged to prevent any tendency for the conductor to pull free from the engaging section 16. The entrance opening 12' is formed to provide an opening slightly larger than the outer diameter of the conductor and its insulating material. The faces of the entrance opening 18 and 20' extend outwardly at the top, taper downwardly a portion of their length and slightly inwardly at 24 and 26' toward the center to form an entrance to the insulation stripping channel 14. The basic difference between the two embodiments lies in the specific construction of the insulation stripping channel. The stripping channel is formed ofa pair of adjacent parallel legs, 18' and 20. A section of each leg forming the stripping or cutting channel 14' is twisted only one-eighth of a turn or 45 (FIG. 7) thereby providing corners 30' facing each other. The facing corners 30 along the length of the stripping channel are then provided with serrations or teeth 28 along their length. The tips of the serrated portion 28 on opposing faces are normally in a slightly spaced-apart parallel position with the distance between them being just slightly larger than the outer diameter of the conductor less its insulating material to prevent damage to the conductor as it is drawn downwardly along the channel.

At the lower end of the stripping channel 14, the faces 18' and 20' touch at the center and form a normally closed entrance 38' to the conductor-engaging section 16. As the

faces

18 and 24 continue downwardly, they present a flat, planar surface 19' and 21' (FIG. 6) and taper slightly outwardly in the conductorengaging section 16 to form the previously described radius of curvature 22' at the bottom.

The operation of the embodiment shown in FIG. 5 is essentially the same as that described with reference to FIG. 4. The basic difference resides, however, in the entrance of the conductor into the stripping channel 14. As the insulated conductor is drawn downwardly, the insulation is cut by the serrated portion exposing the conductor to the connector. As the insulation is removed, the conductor, because of its resilient construction, begins to close toward the conductor. The spacing of the facing portions, however, prevents cutting or damage to the conductor itself. As the conductor is pulled through section 38' and enters the conductorengaging section 16', the legs 18 and 24' are spread apart by the conductor and the parallel planar faces 19' and 21 remove the last traces of insulation, dirt, or oxides from the'wire. As in the previous embodiment, spring tension of the connector on the conductor securely holds the conductor within the engaging section 16'.

A modified connector is illustrated in FIG. 8 wherein a plurality of connectors 10 previously described in connection with FIGS. 1 or 5 are connected in series. This is accomplished by forming the connectors with a link 42 connecting one leg of each connector with an adjoining leg of an adjacent connector. The connectors may, if desired, be provided as a plurality of series connected connectors with a breaking line or indentation 40 formed in the link 42. After annealing and plating, the connectors furnished in strip form may be conveniently separated at the indent 40 when they are to be used.

In FIG. 9, a pair of connectors 10 are shown embedded or molded in a plastic-like insulating holder 44. The holder is provided with parallel openings 43 and parallel slots 46 which open or lead into the channel between the

faces

18 and 20 of the connector 10 when it is placed in the openings 43 therein. This type of holder has been found extremely useful in making rapid jumper connections in existing equipment as well as providing an excellent apparatus for splicing wires. This is accomplished by simply pressing the connector and holder over an existing conductor anywhere along its length with complete assurance that the insulation will be removed and that a perfect electrical connection will be made.

The insertion of a pair of insulated conductors into the connector 10 and insulating block 44 is illustrated in FIGS. 10A through 10D. The operation is essentially that as previously described in connection with FIG. 4. FIG. 10A illustrates the insertion of a first insulated electrical conductor C into one side of the connector embedded in the block 44. The conductor C is drawn along the slotted opening 46 provided in the side of the block 44 and enters the connector 10 in the fashion previously described. FIG. 10B illustrates the completed insertion of the conductor C into the connector 10. The insertion of the second conductor C into the opposite side of the insulating block 44 is accomplished in a similar fashion, that is, by drawing the conductor through the slot 43 provided in the side of the block d4. FIG. 10D shows the completion of the two conductors inserted in the terminal block.

It will, of course, be appreciated that many modifica tions may be made to the invention. A series of individual connectors 10 may, for example, be embedded at their lower portion in an insulated terminal block such as is quite commonly utilized in telephone installations where great numbers of conductors are brought together at a central panel. In another application, the lower end of the connector 10 is conveniently passed through a hole provided in a conventional printed circuit board and soldered in place to provide a terminal on the board for easy and rapid connection of conductors and component lead wires.

It will be readily apparent to those skilled in the art that many other modifications thereof may be made without departing from concepts disclosed herein. Such modifications are to be considered as included in the following claims unless these claims by their language expressly state otherwise.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An electrical circuit connector adapted to conductively engage an insulated conductor comprising: a connector member formed of generally rectangular metallic stock and having a pair of upwardly extending sidewalls forming a conductor-engaging junction at a portion thereof, said sidewalls having upper insulation removing inner facing portions biased toward each other, at least one of said inner facing portions having a plurality of sharpened edge portions formed by twisting said facing portion along a part of its length, said sharpened edge portions being adapted to remove the insulation from an insulated conductor as it is drawn between said walls toward said junction.

2. The electrical connector described in claim 1 and further comprising an insulated housing of plastic-like material formed around said connector, said housing having slotted openings therein in substantial alignment with the openings in said connector.

3. An electrical connector as claimed in claim 1 wherein said sidewalls diverge above said sharpened edge portions to form an entrance opening for said insulated conductor.

4. An electrical connector as described in claim 3 wherein said entrance opening sidewalls form a camlike surface at their lower portion for resiliently separating said sharpened edge portions as said conductor is slid therebetween.

5. The electrical connector as described in claim l and further comprising a plurality of like connectors fixed to each other by a link member extending between said sidewalls forming said entrance opening.

6. The electrical connectors described in claim 5 wherein said link member has an indentation therein to facilitate separation.

7. The electrical connector described in claim 5 and further comprising an insulated housing of plastic-like material formed around said plurality of connectors, said housing having slotted openings therein in substantial alignment with said entrance openings in said connectors.

8. An electrical connector as described in claim 1 wherein each of said sidewalls are twisted to form a plurality of facing sharpened edges on each sidewall.

9. The electrical connector described in claim 8 wherein said connector is formed from resilient square stock coated with a layer of relative inert material having good electrical conductive properties.

10. An electrical connector as set forth in claim 1 wherein said sidewalls converge toward each other from said conductor-engaging portion and form, at their point of convergence, a restricted opening into said conductor-engaging junction portion.

ll. An electrical connector as set forth in claim 10 wherein said point of convergence of said sidewalls operates to clean the insulation from said conductor member as it is drawn therebetween into said conductor-engaging junction portion.

12. An electrical circuit connector adapted to cut the insulation from and conductively engage an insulated conductor comprising: a conductive connector mem-' ber formed of resilient generally rectangular metallic stock having a pair of upwardly extending sidewalls forming an integral, generally U'shaped conductorengaging junction at a lower portion thereof, said sidewalls extending upwardly from said junction forming a conductor-receiving channel therebetween, said sidewalls diverging to form an entrance opening into said channel, said conductor receiving channel having insulation-removing inner facing portions biased toward each other, said inner facing portions being formed by twisting said sidewalls such that corner edges thereof face each other, at least one of said edges having a plurality of, serrated sharpened portions along a part of its length to remove the insulation from an insulated conductor as it is drawn between said sidewalls toward said junction and said upstanding sidewalls converging toward each other below said serrated inner facing portions forming a restricted entrance opening into said conductor-engaging junction portion.

13. An electrical connector as set forth in claim 12 wherein said sidewalls form, at their point of convergence, means to prevent said biased inner facing portions from contacting each other.

14. An electrical connector as set forth in claim 13 wherein said point of convergence of said sidewalls operates to clean the insulation from said conductor member as it is drawn therebetween into said conductor-engaging junction portion.

15. The electrical connector described in claim 14 wherein said connector is formed from resilient stock coated with a layer of relative inert material having good electrical conductive properties.

Claims

4. An electrical connector as described in claim 3 wherein said entrance opening sidewalls form a cam-like surface at their lower portion for resiliently separating said sharpened edge portions as said conductor is slid therebetween.

5. The electrical connector as described in claim 1 and further comprising a plurality of like connectors fixed to each other by a link member extending between said sidewalls forming said entrance opening.

11. An electrical connector as set forth in claim 10 wherein said point of convergence of said sidewalls operates to clean the insulation from said conductor member as it is drawn therebetween into said conductor-engaging junction portion.

12. An electrical circuit connector adapted to cut the insulation from and conductively engage an insulated conductor comprising: a conductive connector member formed of resilient generally rectangular metallic stock having a pair of upwardly extending sidewalls forming an integral, generally U-shaped conductor-engaging junction at a lower portion thereof, said sidewalls extending upwardly from said junction forming a conductor-receiving channel therebetween, said sidewalls diverging to form an entrance opening into said channel, said conductor receiving channel having insulation-removing inner facing portions biased toward each other, said inner facing portions being formed by twisting said sidewalls such that corner edges thereof face each other, at least one of said edges having a plurality of, serrated sharpened portions along a part of its length to remove the insulation from an insulated conductor as it is drawn between said sidewalls toward said junction and said upstanding sidewalls converging toward each other below said serrated inner facing portions forming a restricted entrance opening into said conductor-engaging junction portion.