US 3588788 A
Description (OCR text may contain errors)
I United States Patent Inventor Appl No Filed Patented 4 Assignee Francis A. O Loughlin Scotch Plains, N .1.
Dec. 20, 1968 June 28, 1971 The Thomas & Belts Corporation Elizabeth, NJ.
TWO-PIECE INSULATION PIERCING CONNECTOR 14 Claims, 8 Drawing Figs.
11.5. C1 339/98, 339/276 lnt.C1 HHOIrH/ZO, HOlr 11/08 Field of Search 339/95, 9799, 276
References Cited UNITED STATES PATENTS 2,749,383 6/1956 Pigman et a1. 174/84 3,064,072 11/1962 Graffet a1. 174/87 3,345,452 10/1967 Logan et a1. 174/71 3,376,170 4/1968 Logan ctal. 136/233 3,461,221, 8/1969 Herb 174/84 Primary Examiner-Marvin A. Champion Am'slani Examiner-Joseph H. McGlynn AttorneyThomas M. Marshall ABSTRACT: The connector is made ofa rigid wrought metal insert and a sintered metal body. The body has a bore in which the bars of the insert are mounted and in which the film insulated conductors are received. Upon being compressed, the body forms a gastight electromechanical connection while the bars pierce the film insulation.
Patented June 28, 1911 3,588,788
3 Sheets-Sheet 1 IN VEN TUR. 5/44 03 A 0100mm Patented June 28, 1971 3,588,788
Patented June 28, 1971 3 Sheets-Sheet 5 INVli/YIUA. 4 YC/6 /4 01006194/0 (3 477-0 NEYS TWQ-IIEClE-HNSULATION PIERCING CONNECTOR This invention relates to a two-piece electrical connector. More particularly, this invention relates to a unitized twopiece electrical connector for piercing insulated conductors. Still more particularly, this invention relates to an electrical connector for alternators.
Electrical connectors have been known for connecting at least a pair of electrical conductors together electrically as well as mechanically. In some instances, the connectors have been brazed or soldered to the conductors to insure an electrical or mechanical joint whereas in other instances the connectors have been mechanically crimped onto the conductors. In the latter instances, it has become known to utilize powdered metal connectors for electromechanically connecting two or more conductors together since relatively efficient gastight joints have been afforded thereby. In addition, such powdered metal connectors have allowed an electrical joint made with the sarne'to be fractured without any significant damage, if any, to the conductors due to the frangibility of the connectors. However, while powdered metal connectors have many advantages over other connectors, it has not always been possible to construct these connectors in shapes which facilitate the mounting of a completed electrical joint in an electrical assembly such as an automotive alternator. Further, where the connectors are to connect insulation coated conductors together, the connectors have not been capable of effectively piercing the insulation of the conductors.
Accordingly, it is an object of the invention to provide an electrical connector of a construction suitable for mounting in inconvenient electrical assemblies.
It is another object of the invention to provide an electrical connector which is capable of effectively piercing insulated coated conductors.
It is another object of the invention to pierce the insulation coating of at least a pair of mutually connected insulation coated conductors.
It is another object of the invention to electrically connect an insulated conductor and a stranded wire or an insulated conductor to a bare of tinned solid conductor.
It is another object of the invention to connect an aluminum wire to a copper wire or an aluminum film insulated wire to a copper film insulated wire.
It is another object of the invention to form an efficient electrical connection in an automotive alternator.
Briefly, the invention provides a unitized two-piece electrical connector which is capable of piercing the insulation coating of a coated conductor while also being capable of an efficient mounting in an electrical assembly. The two pieces of the connector are constituted by a powdered metal body and a rigid conductive insert. The body is formed with a bore in which the rigid insert is fixedly mounted while the rigid insert is formed with a plurality of sharp corners or edges within the bore. In use, for example, a pair of insulation coated conductors are placed in the bore over the sharp corners of the rigid element. Thereafter, the body is crimped so as to force the conductors and rigid element together. This causes the insulation on the conductors to deform and stretch over the sharp corners of the rigid element and thereby permits the sharp corners to pierce through the insulation and into the conductors themselves. Since the rigid element remains substantially rigid during crimping of the powdered metal body, the overall dimensions and shape of the connector are substantially preserved.
In one embodiment, the electrical connector includes a body of sintered powdered metal which has a bore for receiving at least a pair of insulation coated conductors and a flag terminal strip of wrought metal which has a plurality of digitated bars fixed within the bore of the powdered metal body. The corners of these bars are formed with sharp corners or edges in order to pierce the insulation of the conductors upon crimping of the body of the connector. In addition, the flag terminal is formed with an aperture which facilitates mounting of the connector on or in an electrical assembly such as an alternator.
In another embodiment, the electrical connector is formed of a body of sintered powdered metal having a bore for receiving an insulation coated conductor and a rigid insert of wrought metal having at least a pair of bars as above within the bore. The rigid insert is formed with the bars in a U-shape or oval shape within the confines of the bore so as to receive an insulated coated conductor between the legs. The corners of the legs are further positioned with respect to the conductor to pierce the coating of the conductor in the bore upon compression of the body at two points. This conductor can be further formed so as to be mounted in an electrical assembly in any suitable manner, for example, in the manner of a standoff and feed through connector.
These and other objects an advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a perspective view of an electrical connector according to the invention;
FIG. 2 illustrates a view taken on line 2-2 of FIG. 1;
FIG. 3 illustrates an exploded perspective view of the connector of FIG. 1;
FIG. 4 illustrates a duplication of a microphotograph of an electrical connection between three insulation coated conductors and the connector of FIG. 1;
FIG. 5 illustrates a modified connector according to the invention;
FIG. 6 illustrates a view taken on line 6-6 of FIG. 5;
FIG. 7 illustrates an end view of another modified connector according to the invention; and
FIG. 8 illustrates a plan view of the connector of FIG. 7.
Referring to FIGS. 1 to 3, the connector 10 is formed of a sintered powdered metal body 11 and a flag terminal 12 of rigid material such as a wrought metal which are secured together as a unit. The body 11 is ofa block shape with a substantially rectangular cross section and rounded edges. In addition, the body 11 has a bore 13 which passes completely through the body 11 on the longitudinal axis of the body 11. The bore 13 is initially formed with a flat insert receiving section 13' and a formed conductor receiving section 13". The insert receiving section 13' has a flat floor surface 14 and a pair of flat wall surfaces 15 whereas the conductor receiving section 13" has a vaulted roof 16 formed of a plurality of parallel longitudinally aligned arches 17 wherein each pair of adjacent arches forms a ridge with a pointed edge 18 and rounded wall surfaces 19. The rounded wall surfaces 19 project into the bore 13 above the insert receiving section 13' to further define the upper limit of the insert receiving section 13'. The flag terminal 12 is formed in a flat shape for example of a single thickness and includes a main section 20 having a formed aperture 21 therein and a digitated bar section 22 having a plurality of parallel bars 23, for example, four. The aperture 21 in the main section 20 is sized to fit over a suitable terminal post (not shown) so as to mount the connector 10 in place. The bars 23 project from one side of the main section 20 to seat within the bore 13 of the body 11. In addition, the outermost bar 23 is spaced from the end of the main section 20 so as to form a shoulder 24 therewith.
Referring to FIG. 2, the digitated bar section 22 is sized to fit into the insert receiving section 13' of the bore 13 of the body 11 and reset on the floor 14. Once the bars 23 are inserted into the bore 13 their full length so that the body 11 abuts the shoulder 24 of the terminal 12, the wall surfaces 15 of the body 11 are crimped or staked under a slight compressive force to fix the bars 23 in place within the bore 13 so that a one-piece unit is formed of the body 11 and terminal 12.
Referring to FIG. 3, the edges 18 formed in the bore roof 16 and the bares 23 are oriented with respect to each other so that each edge 18 is located in the plane of a bar 23 and in spaced relation thereto. Additionally, the bars 23 are each of a rectangular cross section with sharply defined edges 25. When the unitary connector 10 is formed, the bars 23 and bore 13 are spaced apart to receive the ends of film insulated wire conductors, such as magnet wire, as well as standard wire conductors. Further, the body 11 is made of sintered powdered metal such as aluminum, copper, alloys, and the like suitable for forming an electrical and mechanical joint with the conductors while the flag terminal 12 is of similar wrought metallic material. In this manner, the minimum spring back characteristic of powdered metal and the rigidity of wrought metal for insulation piercing are combined. That is, the material and shape of the body is such as to permit deformation of the body without deformation of the flag terminal insert under an applied compression force. Relatively speaking, as the body is made of a sintered powdered material and therefore is less than I percent density, the insert which is of a wrought material and therefor of 100 percent density (assuming wrought material to be the optimum practical density obtainable) is harder than the body.
Referring to FIG. 4, in order to form an electrical and mechanical connection with a plurality of film insulated wire conductors 26, for example, for an automotive alternator or for any motor leads to a terminal board, the ends of the conductors 26 are slidably positioned in the bore 13 of the body 11 over the bars 23. Next, a compressive force is exerted on the body 11 perpendicularly of the floor 14 and roof 16. This force is of a magnitude to cause the body 11 to collapse or flow in a manner to flatten about the conductors 16 while forcing the conductors 26, which in this example total three, against and between the bars 23. As the compressive deformation of the body 11 continues, the insulation film about the wire conductors is stretched and extruded into the spaces between the bars 23 and the sharp corners 25 on the bars 23 pierce through the insulation film. Upon piercing the insula tion film, the sharp edges 25 of the bars 23 begin to penetrate the metal of the wire conductors 26 while the deformation of the body 11 and the conductors 26 continues. Upon release of the compressing force, the bars 23 are in electrical contact with the wire conductors 26 while the conductors 26 are mechanically fixed within the deformed bore 13 of the body 11 in a gastight joint.
It is noted that the compressive force needed to deform the body 11 is such as to cause compressive deformation of the body 11 without failure of the body 11 in compression and without any substantial deformation of the bars 23 of the terminal 12.
It is further noted that FIG. 4 illustrates an actual electromechanical connection between three 015 magnet wires and a connector having a body 11 of about 0.280 inches by 0.288 inches and a height of 0.180 inches, an insert receiving portion of 0.198 inches by 0.045 inches and a conductor receiving portion having surfaces formed on a 0.033 inch radius. The bars 22 are spaced 0.032 inches apart and are 0.020 to 0.0l8 inches thick while the two inner bars are 0.032 inches wide.
The body 11 can further be made in a manner wherein the material constituting the body is frangible, or fracturable, upon being subjected to a disruptive tensile force. Thus, in the event that the connection between the connector and the conductors 26 requires disjoinder, a disruptive tensile force can be imposed on the connector 10 to separate the connector from the conductors without damaging the conductors.
Referring to FIGS. 5 and 6, the connector 30 is constructed to act as a standoff and feed through insulation piercing connector. In this instance, the connector 30 has a body 31 of sintered powdered metal which is shaped with an upper eyelet portion 32 an a rigid inset 34 of wrought metal fixed within the eyelet portion 32. The eyelet portion 32 has a bore 35 with an insert receiving portion 35 of rectangular shape and a conductor receiving portion 35" of generally arch shape with flat sidewalls. The rigid insert 34 is of U-shaped configuration ofa single thickness with rectangular dimensions to form a pair of bars 36 which fit within the insert receiving portion 35' of the body 31. The bars 36 are each formed of rectangular cross section with sharp edges 37, as above, and project into the bore 35.
The body 31 is also formed with a lower conductor engaging portion 38 and a crossbar 39 transverse to the axis of the body 31. The lower conductor engaging portion 38 is bifurcated to fit around a conductor or terminal and form an electrical contactthcrewith. The crossbar 39 is sized to fit within a suitable holder as is known so as to-maintain a separation between the conductors engaged by the opposite ends of the body 31.
The connector 30 is used in a manner similar to that described above in that a single film insulated wire conductor (not shown) is initially passed through the bore 35 and thereafter the eyelet portion 32 is compressively deformed about the conductor. This permits the sharp edges 37 of the insert bars 36 to pierce the film insulation, as above, and to penetrate into the wire conductor to form an electrical connection. Also, as above, a gastight electromechanical connection is formed. In order to disrupt the connection, the body 30 is subjected to a disruptive tensile force which shatters the body due to the body's frangibility.
Referring to FIGS. 7 and 8, the connector 40 is constructed as with blocklike body 41 having a substantially rectangular cross section with rounded sidewalls. The body 41 also ha a pair of parallel bores 42, 43 passing longitudinally therethrough parallel to the rounded sidewalls. One bore 42 is of a circular configuration to receive a bare conductor such as a standard wire, a solid conductor, or a tinned copper wire. The other bore 43 is of a generally U-shaped contour and has an enlarged portion 43 at one end and a partially reduced portion 43" at the other end so that a tapered shoulder 44 is formed at an intermediate point, e.g. the midpoint, within the bore 43. In addition, the connector includes a rigid insert 45 of wrought metal fixed within the reduced portion 43" of the contoured bore 43 above the plane of the shoulder 44. In this way, the reduced portion 43" provides a strain relief for the insert 45. This insert 45 is similar in construction to the insert 34 shown in FIGS. 5 and 6 and need not be further described. Also, the body 41 is ofa suitable sintered metal material such as copper while the insert 45 is of a rigid material such as brass, wrought copper, and the like.
The connector 40 is formed by initially inserting the insert 45 into the upper area of the reduced portion 43" of the contoured bore 43 up to the shoulder 44. The connector body 41 is then compressed slightly to secure the insert 45 in the bore 42 under a slight compressive force. Alternatively, any other suitable type of fit can be used to secure the insertion within the body. After assembling, the connection 40 can be hot tinned.
In use, a first conductor such as a tinned copper wire is inserted into the circular bore 42 of the connector body 41 while a second insulated conductor such as a film insulated aluminum magnet wire is inserted into the contoured bore 43 to lie within a portion within the plane of the bars of the insert 45. Next, with the use of a suitable tool, the connector 40 is deformed by a compressive force applied substantially uniformly about the circumference of the body 41 while the rounded sidewalls provide relief areas. The force is applied to such a degree that the bores 42, 43 completely close upon the respective conductors to form a gastight joint while the corners of the bars of the insert 45 pierce through the insulation of the conductor in the contoured bore 43 to contact the conductor metal. As above, a gastight electromechanical connection is formed which can be broken upon subjecting the body 41 to a disruptive tensile force.
The invention thus provides an electrical connector which can be readily used to pierce the film insulation of so coated wire conductors in order to obtain an electromechanical joint. The connectors of the invention further permit their use in various electrical units and assembly such as altemators in a simple manner which easily effects the mounting of the pierced conductors within the electrical unit.
Further, the invention facilitates the electrical connection of two or more film insulated conductors in a rapid reliable manner while also providing a gastight connection of excellent electrical properties. The connectors further are useful since the conductors can be mounted in place before the connector is mounted in place.
The connectors of the invention can thus be used to connect insulated conductors and stranded wire conductors as well as insulated conductors and bare or tinned solid conductors. Further, the connectors can be used to connect aluminum wire to copper wire as well as aluminum film insulated wire to copper film insulated wire.
l. A connector comprising a body of sintered powdered metal having a bore therein for receiving at least one electrical conductor and an insert including a main portion having an aperture therein outside said body and a digitated portion having at least a pair of said bars fixedly mounted in said bore, said bars having sharp edges for penetrating the conductor in said bore upon compressive deformation of said body.
2. A connector as set forth in claim 1 wherein said insert is harder than said body.
3. A connector as set forth in claim ll wherein said body is made of a sintered powdered aluminum and said insert is made of wrought aluminum.
4. A connector as set froth in claim 1 wherein said body has a roof defining said bore, said roof having a plurality of ridges extending longitudinally therethrough in spaced relation to said insert.
5. A connector as set forth in claim 1 wherein said connector is made of powdered copper.
6. A connector as set forth in claim 1 wherein said body includes a surface having a plurality of edges spaced from said bars, each said edge being disposed in the plane ofa respective one of said bars.
7. A connector as set forth in claim 6 wherein said insert is made of wrought metal.
8. A connector as set forth in claim 1 wherein said body is a die casting and said insert is of a material harder than said body.
9. A connector as set forth in claim 8 wherein said body is a die casting ofzinc.
110. A connector comprising a body of sintered powdered metal having a bore therein for receiving at least one electrical conductor and an insert having at least one bar in said bore, said bar having a sharp edge for penetrating the conductor in said bore upon compressive deformation of said body, said body being of block shape and said bore passing longitudinally through said block, and said insert being a flag terminal including a main portion having an aperture therein outside said body and a digitated portion fixed within said bore.
ill. A connector as set forth in claim 10 wherein said insert is made of wrought metal.
112. A connector comprising a body of sintered powdered metal having a bore therein for receiving at least one electrical conductor and an insert having at least one bar in said bore, said bar having a sharp edge for penetrating the conductor in said bore upon compressive deformation of said body, said body having an eyelet portion including said bore therein, and said body having a conductor engaging portion at one end opposite said eyelet portion and a crossbar therebetween.
13. A connector comprising of body of sintered powdered metal having a first bore therein for receiving at least one electrical conductor and an insert having at least one bar in said first bore, said bar having a sharp edge for penetrating the conductor in said first bore upon compressive deformation of said body, said insert being received in said first bore, and wherein said body further includes a second bore therein for receiving a second conductor, and said first bore having a shoulder at an intermediate point separating a partially reduced portion from an enlarged portion.
141. A connector as set forth in claim 13 wherein said second bore is circular.