US 3512123 A
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Description (OCR text may contain errors)
May 12, 1970 J. s. COSTELLO ETAL 3,512,123
GUIDE AND CRIMP-LOCATING MEANS IN ELECTRICAL CONNECTORS AND METHOD AND APPARATUS FOR MAKING SAME Filed Dec. 22, 1966 2 Sheets-Sheet 1 3,512,123 IN ELECTRICAL CONNECTORS 2 Sheets-Sheet 2 OR MAKING SAME J. S. COSTELLO ETA!- AND METHOD AND APPARATUS F GUIDE AND CRIMP-LOCATING MEANS May 12, 1970 Filed Dec. 22, 1966 Zlx United States Patent US. Cl. 339-276 9 Claims ABSTRACT OF THE DISCLOSURE An electrical connector is provided with tapered surface means along the internal surface of a dielectric sleeve and at the entrance to a ferrule defining funnel means to guide a conductive portion of an insulated conductor means within the ferrule. Groove means are provided in an exterior surface of the dielectric member about a central portion of the ferrule to define crimplocating means for locating the crimping dies of a crimping tool in proper relationship along the ferrule so that an effective crimp can be made.
This invention relates to electrical connectors and more particularly to electrical connectors having guide and crimp-locating means and a method of making same.
Electrical connectors are used in large quantities for terminating electrical Wires and for making electrical connections. One drawback of present day electrical connectors is that no guide means is provided to eifectively guide the conductive portions of electrical wire means into crimping sections of the electrical terminals. Another drawback is that no crimp-locating means is provided on the electrical connectors to properly locate crimping-die means relative to the crimping sections.
It is therefore desirable to have on electrical connectors guide means on the interior surface of an insulation support member adjacent a crimping section of the electrical terminal in order to guide the conductive portion of wire means into the crimping section so that the conductive portion can be crimped within the crimping section. It is also desirable to have on electrical connectors crimplocating means to properly position crimping-die means relative to the crimping section so that a proper crimp can be effected to provide an excellent mechanical and electrical connection.
An object of the invention is to provide an electrical connector having guide means to guide a conductive position of wire means into a crimping section of the electrical connector.
Another object of the invention is the provision of crimp-locating means on an electrical connector to properly position crimping-die means relative to a crimping section of the electrical connector.
A further object of the invention is to provide an electrical connector with. guide means to guide a con ductive portion of Wire means into a crimping section of the electrical connector and crimp-locating means on the electrical terminal to properly position crimping-die means relative to the crimping section of the electrical connector.
An additional object of the invention is the provision of an electrical connector having an insulation support section to accommodate insulation of wire means to be crimped in the crimping section.
A still further object of the invention is the provision of a method of forming guide and crimp-locating means on an electrical connector.
Other objects and attainments of the present invention will become apparent to those skilled in the art upon "ice a reading of the following detailed description when taken in conjunction with the drawings in which there are shown and described illustrative embodiments of the invention; it is to be understood, however, that these embodiments are not intended to be exhaustive nor limiting of the invention but are given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.
The foregoing and other objects are achieved by a preferred embodiment of an electrical connector which comprises connection section means for electrical connection to a conductive member, crimping-section means for crimping onto a conductive portion of electrical wire means, sleeve means having a first section carrying the crimping-section means and a second section for engagement with insulation of the electrical wire means, guide means on an interior surface of the second section for guiding the conductive porton of the electrical wire means into the crimping-section means, and crimp-locating means on the first section for positioning crimping die means relative to the crimping-section means.
In the drawings:
FIG. 1 is a perspective view of an electrical connector;
FIG. 2 is a longitudinal cross sectional view of FIG. 1;
FIG. 3 is a perspective view of an alternative embodiment;
FIG. 4 is a longitudinal cross-sectional view of FIG. 3;
FIG. 5 is a perspective view of another embodiment;
FIG. 6 is a longitudinal cross-sectional view of FIG. 5;
FIG. 7 and 8 illustrate an apparatus for forming a sleeve for the electrical connector of FIGS. 1 and 2; and
FIG. 9 illustrates apparatus for forming a sleeve for the electrical connector of FIGS. 5 and 6.
Turning now to FIGS. 1 and 2, there is illustrated an electrical connector EC which comprises a metallic part 1 and a dielectric part 2. Metallic part 1 inludes a lug 3 and a ferrule 4. Lug 3 has an opening 5 therein so that the electrical connector can be connected to a conductive member thereby in accordance with conventional electrical connection techniques. Lug 3 can however take any suitable form to effect an electrical connection with another electrical condutive member. The ferrule 4 is a sleeve and defines a crimping section in which a conductive portion of an electrical wire means is crimped. Serrations 6 are formed on the interior surface of ferrule 4 in order to increase the tensile between ferrule 4 and the conductive portion of the electrical Wire means as well as to score the conductive portion to break down the oxide coating on the conductive portion to increase electric conductivity. The entrance of ferrule 4 has a beveled surface 7.
Metallic part 1 is susceptible to mass production by automatic machinery and is conveniently formed by shaping a sheet metal blank or strip of a suitable electrically-conductice metal such as brass, bronze, or the like in successive forming steps. The metal is sufficient- 1y hard and resilient to impart to the crimping section a spring-like character, yet it is sufiiciently malleable to permit cold forging or crimping of the crimping section onto a conductor means to provide an excellent electrical and mechanical connection.
Dielectric part 2 is a suitable plastic material such as, for example, polyvinyl chloride, nylon or the like which is susceptible to cold-forming techniques. Dielectric part 2 is a sleeve and includes a brst section 8 and a second section 9. First section 8 has a circumferential groove 10 which is centrally located with respect to ferrule 4 and defines crimp locating means in which die means of a crimping tool are disposed to properly locate the die means relative to ferrule 4 so that a proper crimp can be effected on the conductive portion of the electrical wire means to obtain an excellent mechanical and electrical connection. Groove 10 has sufiicent width to extend along a sufficient length of ferrule 4.
Second section 9 includes a first portion 11 and a second portion 12. First portion 11 is frusto-conical in configuration and second portion 12 is cylindrical in configuration so that electrical connector EC can accommodate the insulation of electrical wire means. An annular projection 13 is located at the juncture of first section 8 and second section 9 of dielectric part 2. The dimension of annular projection 13 is such that the inside surface of first portion 11 is tapered and merges with beveled surface 7 to define a substantially constant tapered surface therebetween thereby providing funnel or guide means to effectively lead the conductive portion of electric wire means into ferrule 4. Annular projection 13 also serves to limit the movement of ferrule 4 within first section 8 of dielectric part 2 so that circumferential groove 10 is properly positioned relative to ferrule 4.
Electrical connector ECa illustrated in FIGS. 3 and 4 is similar to electrical connector EC of FIGS. 1 and 2 except that second section 9a of dielectric part 2a of electrical connector ECa has a substantially constant outside diameter therealong. It is to be noted however that first portion 11a of second section 9a includes an inner surface of frusto-conical configuration which merges with beveled surface 7a of ferrule 4a thereby defining a substantially constant tapered surface between first portion 11:: of dielectric part 2a and the entrance to ferrule 4a of metallic part 1a to provide the funnel means to permit the ready insertion of the conductive poriton of the electrical wire means into ferrule 4w.
Electrical connector ECb illustrated in FIGS. 5 and 6 is directed to an electrical connector to splice the ends of electrical Wire means together. As can be discerned, ferrule 4b is similar to ferrules 4 and 4a except that ferrule 4b is made as a ferrule having two ferrule sections in which respective ends of conductive portions of electrical wire means are crimped. The ferrule sections of ferrule 4b are separated by spaced indents 14 which act as a stop means to limit the movement of the conductive portions of the electrical wire means withing the ferrule sections. Dielectric part 2b is similar to dielectric part 2a with first portion 11b having tapered surfaces merging with beveled surfaces 7b of the ferrule sections of ferrule 4b to provide the guide means to guide the conductive portions of the electric wire means within the ferrule sections of ferrule 4b. Circumferential grooves 10b are also located over respective ferrule sections to provide crimp-locating means for the ferrule sections. Annular projections 13b lock ferrule 4b in position Within dielectric part 2b. Second sections 9b of dielectric part 2b may have a configuration similar to first portion 11 and second portion 12 of the dielectric part of electrical connector EC of FIGS. 1 and 2.
Turning now to FIGS. 7 and 8, there is illustrated a method and apparatus for forming dielectric part 2 of electrical connector EC. The apparatus in FIGS. 7 and 8 comprise mold parts 15 and 16 each having a projection 17, beveled surfaces on each side of projection 17, a tapered surface 19 and straight surfaces 20, 20' all of which are semi-circular in cross section since each of mold parts 15 and 16 constitute one half of mold M.
A movable compound ram 21 includes a first ram member 22 and a second ram member 23. First ram member 22 is a rod that snugly fits within an opening 24 of second ram member 23 and each ram member is movable with respect to each other. The inner end of 4 first ram member 22 has a blind hole 25. The inner end of second ram member 23 has a reduced section 26 and a stop surface 27. A movable ram 28 comprises a cylindrical section 29, a tapered section 30, a straight section 31, a pushing surface 32 and a stop surface 33.
In operation, mold parts 15 and 16 of mold M are spaced from each other and rams 21 and 28 are positioned so that a tubular member 34 of suitable plastic material of proper length is placed within open mold M onto first ram member 22. Mold parts 15 and 16 are brought into engagement to form mold M and are held in a closed position by conventional means. Rams 21 and 28 are moved toward each other by conventional driving means so that reduced section 26 snugly and tightly mates with straight surfaces 20' and stop surface 27 engages mold parts -15 and 16 thereby limiting the movement of ram 21 within mold M but continuous pressure is applied to ram 21 to maintain it in this position.
Ram 28 continues to move within mold M with tapered section 30 engaging tubular member 34 thereby causing tubular member 34 to be increased in diameter as ram 28 moves inwardly. Ram 28 continues to move within mold M until cylindrical section 29 bottoms in blind hole 25, pushing surface 32 pushes against an end of tubular member 34 and stop surface 33 engages mold parts 15 and 16. The section of ram 28 between pushing surface 32 and stop surface 33 fits snugly within straight surfaces 20'.
The action of ram 28 moving within mold M causes tubular member 34 to be moved into engagement with tapered surfaces 19 and straight surfaces 20 by tapered section 30 and straight section 31 to form first portion 11 and second portion 12 of dielectric part 2.
With ram 21 being held in position so that the inner end of reduced section 26 is in engagement with the other end of tubular member 34, the engagement of pushing surface 32 of ram 28 with the one end of tubular member 34 as ram 28 is being moved inwardly causes the material of tubular member 34 to flow into beveled surfaces 18 which forms the crimp-locating means and to flow into the area created by the inner end of ram member 22 and tapered section 30 of ram 28 thereby forming annular projections 13 at the juncture of first section 8 and second section 9 of dielectric part 2 and a tapered surface which merges with beveled surface 7 which form a substantially constant tapered surface therebetween to define the guide means.
Mold M is opened and rams 21 and 28 are positioned so that the newly formed dielectric part can be removed therefrom. After dielectric part 2 has been formed by the apparatus in FIGS. 7 and 8, ferrule 4 of metallic part 1 is inserted in first section 8 of dielectric part 2 to form electrical connector EC of FIGS. 1 and 2. The inside diameter of first section 8 is such so that ferrule 4 is held therein by friction therebetween. The completed electrical connector is now ready to be crimped onto an electrical wire means with the guide means effectively guiding the bared conductive portion of an electrical wire means into ferrule 4 and the crimp-locating means properly locating crimping-die means to crimp ferrule 4 onto the conductive portion of the electrical wire means. Second section 9 of dielectric part 2 may be crimped onto the insulation of the electrical wire means to provide strain relief.
The mold to form dielectric part 2a for electrical connector ECa of FIGS. 3 and 4 is the same as the mold to form dielectric part 2 except that tapered surfaces 19 and straight surfaces 20 have the same diameter.
FIG. 9 illustrates mold Ma to form dielectric part 2b of FIGS. 5 and 6. Mold Ma includes mold parts 35 and 36. Each of mold parts 35 and 36 includes on the interior surface spaced projections 37, beveled surfaces 38 on each side of spaced projections 37 and straight surfaces 39.
Spaced projections 37, beveled surfaces 38 and straight surfaces 39 are semi-circular in cross section.
Compound rams 40 are insertable within mold Ma and include first ram members 41 and second ram members 42. Ram members 41 are snugly disposed in openings 43 of ram members 42 so that ram members 41 are movable relative to ram members 42 and relative to each other. Ram members 41 include rounded-nose sections 44, tapered sections 45 and cylindrical sections 46. Ram members 42 include reduced sections 47 and stop surfaces 48.
In operation, mold parts 35 and 36 are spaced from each other and rams 40 are positioned so that a tubular member 49 of suitable dielectric material and of proper length with ferrule 4b therein can be placed within mold Ma. Mold parts 35 and 36 are closed and held by conventional means; rams 40 are simultaneously moved within the mold by conventional driving means. As rams 40 move within mold Ma, ram members 41 position ferrule 4b so that the ferrtfle sections thereof are properly positioned relative to projections 37 by means of roundednose sections 44 being positioned within the ferrule sections of ferrule 4b and tapered sections 45 engaging the beveled surfaces of the ferrule sections. Reduced sections 47 fit snugly in straight surfaces 39 and the inner ends of the reduced sections of ram members 42 engage respective ends of tubular members 49 as rams 40 are being driven inwardly thereby applying pressure to the tubular member toward the center thereof causing the material of tubular member 49 to flow into beveled surfaces 38 to form the crimp-locating means and to flow into the areas between the ends of ferrule 4b and tapered sections 45 to form annular projections 13b and tapered surfaces so that the inner surface of tubular member 49 is tapered on each side of the ferrule and these tapered surfaces merge with the beveled surfaces of ferrule 4b which form substantially constant tapered surfaces therebetween to define the guide means. Rams 40 are moved out of mold Ma and mold parts 35 and 36 are moved apart so that electrical connector ECb can be removed from the mold.
The formation of tubular member 49 into dielectric part 2b by mold Ma and rams 40 forms a completed connector with ferrule 4b locked into position within dielectric part 2b by annular projections 13b. A small amount of material of tubular member 49 may flow into spaced indents 14 but this will not impair the formation of the crimp locating means by projections 37 and beveled surfaces 38. If desired, spaced projections 37 may be a solid projection thereby eliminating inner beveled surfaces 38 so that the groove formed by the single projection will be substantially constant in diameter throughout and the flow of material into indents 14 will then occur. A continuous groove along substantially the entire length of ferrule 4b will still perform the function of locating crimping die means relative to the ferrule sections of ferrule 4b because each side of the groove will properly locate the crimping die means relative to the crimping sections of ferrule 4b. Ribs may be formed partially around the first section of the dielectric part instead of being formed entirely therearound as preferred.
The formation of the crimp-locating means and guide means in the plastic tubular member by molds M and Ma and associated .rams is accomplished only by the application of pressure on the rams thereby subjecting the plastic tubular member to a cold-forming operation.
The formation of dielectric part 2a of FIGS. 3 and 4 and 2b of FIGS. 5, 6, and 9 may be a two-step operation instead of a one-step operation. This is accomplished by placing within the tubular members of dielectric material to form dielectric parts 2a and 2b a rod of constant diameter within the tubular members and ram members would engage the ends of the tubular members to first form the crimp-locating means. The rods would be replaced by suitable ram members to then form the guide means Within the tubular member in the case of dielectric 6 part 2a, and, in the case of dielectric part 2"b, ferrule 4b and ram members 41 would be used in the second operation to form annular projections 13b and the guide means.
After formation of dielectric part 2a of FIGS. 3 and 4, second section 9a can be subjected to controlled expansion to expand this section to any desired diameter within the limits of expansion of the material. This would also be true with respect to dielectric part Zb of FIGS. 5 and 6. i
From the foregoing, there has been disclosed a unique and novel electrical connector having formed on the dielectric part thereof guide and crimp-locating means in a one-step cold-forming operation and a completed electrical connector for splicing wires together as a complete electrical connector provided with guide and crimplocating means in a one-step cold-forming operation.
It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiments of the invention, which are shown and described herein, are intended as merely illustrative and not as restrictive of the invention.
The invention is claimed in accordance with the following:
1. An electrical connector for mechanical and electrical connection to insulated wire means comprising, in combination, a metallic part and a dielectric part, said metallic part comprising a ferrule, said ferrule having an inside surface provided with a beveled surface at one end, said dielectric part defining a sleeve comprising a first part and a second part, said first part being in engagement with said ferrule and surrounding said ferrule, said first part having groove means disposed along substantially a central section of said ferrule to define crimp-locating means to locate crimping-die means to crimp said ferrule onto a conductive portion of said insulated wire means, an annular projection on an inside surface of said sleeve at the juncture of said first and second parts, said annular projection being disposed adjacent said beveled-surface end of said ferrule, said inside surface of said second part having a tapered surface merging with said beveled surface to define a substantially constant tapered surface therebetween to provide guide means to guide said contive portion of said insulated wire means into said ferrule.
2. An electrical connector according to claim 1 wherein said groove means constitutes a circumferential groove.
3. An electrical connector according to claim 1 wherein said second part includes a frusto-conical portion and a cylindrical portion.
4. An electrical connector according to claim 1 wherein said second part has a substantially constant outside diameter.
5. An electrical connector for joining two lengths of insulated wire means comprising, in combination, a metallic ferrule and a dielectric sleeve, said ferrule comprising ferrule sections having beveled surfaces at entrances thereto, said sleeve having a first part surrounding said ferrule and second parts extending outwardly beyond said entrances, annular projections at the junctures of said first part and second parts to secure said ferrule in position within said sleeve, said second parts having tapered surfaces on inside surfaces thereof merging with said beveled surfaces to define substantially constant tapered surfaces therebetween to provide guide means to guide conductive portions of said wire means itno said ferrule sections, and crimp-locating means on said first part defining groove means extending along said ferrule to locate crimping-die means for crimping said ferrule sections onto said conductive portions of said wire means.
6. An electrical connector according to claim 5 wherein said groove means defines a circumferential groove.
7. An electrical connector according to claim 5 wherein said groove means constitutes a circumferential groove disposed over each of said ferrule sections and along a central section of each of said ferrule sections.
8. An electrical connector according to claim 5 wherein said ferrule includes means to limit the movement of said conductive portions of said wire means into said ferrule sections.
9. An electrical connector comprising, in combination, metal ferrule means and dielectric sleeve means, said ferrule means having a tubular configuration and a beveled surface at least at one end thereof, said dielectric sleeve means having a first section of tubular configuration in which said ferrule means is disposed and a second section extending axially outwardly beyond the beveled-surface end of said ferrule means, an interior surface of said sleeve means having projection means in engagement with the beveled-surface end, said projection means having a tapered configuration merging with said beveled surface thereby defining a substantially constant tapered surface between the interior surface of said second section adjacent said projection means and an interior surface of said ferrule means, and groove means disposed in said first section along an exterior surface thereof and being disposed substantially centrally of said ferrule means.
References Cited UNITED STATES PATENTS 2,681,440 6/1954 Swengel.
2,774,810 12/ 1956 Ritter 339-223 X 2,958,723 11/ 1960 Logan et al 339-276 X 2,981,787 4/ 1961 Brautigam et al. 339-276 X 2,982,808 5/1961 Schwester 339-276 X 3,173,989 3/ 1965 Neaderland 339-276 X 3,356,987 12/ 1967 Gillespie 339-276 X FOREIGN PATENTS 1,347,726 11/ 1963 France.
RICHARD E. MOORE, Primary Examiner J. H. MCGLYNN, Assistant Examiner