Pre-loaded Electrical Connector

Abstract

Pre-loaded multi-contact electrical connector has contact terminals therein which have tubular conductor receiving portions. The conductor receiving portion has an axially extending open seam which defines a slot for the reception of the conductor. Upon movement of the conductor laterally of its axis and into the slot, the edges of the slot engage, and establish electrical contact with, the conductor.

Description

BACKGROUND OF THE INVENTION

This invention relates to electrical connections of the type in which a wire or other conductor is moved laterally of its axis into a slot in a terminal member so that the edges of the slot engage, and establish electrical contact with, the conductor. The invention is herein disclosed in an embodiment comprising a preloaded multi-contact electrical connector, however, the invention can be used under other circumstances where conductors are connected to terminal members which are contained in a housing.

It is common practice to electrically and mechanically connect a conductor to a terminal member by providing a narrow slot in the terminal member and moving the conductor laterally of its axis into the slot so that the edges of the slot engage, and establish electrical contact with, the conductor. These wire-in-slot terminal devices can be manufactured by simply punching a narrow slot in a plate-like portion of the terminal as shown, for example, in the U.S. Pat. to Levin U.S. Pat. No. 3,012,219 or by punching an elongated enclosed slot in a thin plate-like member and then folding the plate-like member about a fold line which extends transversely of the slot. This latter manufacturing technique provides two slots for the conductor and has certain advantages as described in the U.S. Patent to Patton U.S. Pat. No. 3,617,983. The U.S. patents to Zeanis U.S. Pat. No. 3,147,058 and Pasternak U.S. Pat. No. 3,027,536 show further conductor-in-slot type devices of the general type under consideration here.

We have found that a high quality conductor-in-slot plate electrical connection can be achieved by forming a flat blank into a tubular shape having an seam open which functions as the conductor-receiving slot of the terminal. Several advantages are achieved in accordance with our invention including ease of manufacture, an improved ability in the terminal to accomodate conductors of different sizes, and a conductor-terminal connection having improved mechanical and electrical characteristics.

The herein disclosed embodiment of the invention is in the form of a multi-contact electrical connector of the type used for connecting individual conductors to the conductors on a printed circuit board. The conductors can be connected to the terminals in the connector by the use of a conductor trimming and inserting apparatus as shown in application Ser. No. 347,965, filed of even date herewith. The connector shown herein has especial utility in the manufacture of electrical harnesses as disclosed in application Ser. No. 347,957.

It is an object of the present invention to provide an improved conductor-in-slot type electrical connecting device. A still further object is to provide a conductor-in-slot terminal device which is capable of receiving and forming electrical connections with, conductors of varying sizes. A further object is to provide a conductor-in-slot type terminal device which is capable of receiving a plurality of wires or other conductors. A further object is to provide an improved pre-loaded multicontact electrical connector.

These and other objects of the invention are achieved in a preferred embodiments thereof which are briefly described in the foregoing abstract, which are described in detail below, and which are shown in the accompanying drawing in which:

FIG. 1 is a perspective view of an electrical connector in accordance with the invention having individual wires connected to the contact terminals in the connector.

FIG. 2 is an exploded view of the connector of FIG. 1.

FIG. 3 is a cross-sectional view of the housing of the connector taken along the lines 3--3 of FIG. 2.

FIG. 4 is a cross-sectional view taken along the lines 4--4 of FIG. 1.

FIG. 5 is a fragmentary plan view, with parts broken away, of the connector of FIG. 1.

FIG. 6 is a fragmentary plan view of a portion of the housing illustrating the manner in which a single coarse wire is accomodated in the terminal.

FIg. 7 is a sectional side view of one form of apparatus for trimming individual conductors and inserting the trimmed conductors into the slots of the terminals in the connector, this view showing the apparatus with the parts in their open positions.

FIG. 8 is a fragmentary view on an enlarged scale of the apparatus of FIG. 7 shown in the positions of the parts at the conclusion of a wire trimming and inserting operation.

As shown in FIGS. 1 and 2, a connector 2 in accordance with the invention serves to connect individual wires 6 to the conductors 8 on a printed circuit board 4. The connector comprises a housing 10 of suitable insulating material, such as molded plastic, having a mating or forward side 12 and a rearward side 14. A plurality of side-by-side contact receiving cavities 16 extend through the housing from the rearward side to the mating side and a contact terminal 18 is mounted in each of each of these cavities.

The terminals are of stamped and formed sheet metal and each terminal has at its forward end a flat tongue 20 which is reversely bent at 22 to provide a rearwardly extending contact portion 24 for engagement with the conductors 8 on the printed circuit board 4. The contact portion in the disclosed embodiment is bifurcated at its free end so that it has two separate points of contact with the conductor 8. A lance or tang 26 is struck from the tongue 20 for the purpose of retaining the terminal in the cavity as will be described below. The rearward end 28 of each terminal 28, constitutes the conductor receiving portion of the terminal and is generally tubular having a web 30, which is co-planar with the tongue 20, and sidewalls 32, which are formed inwardly and towards each other at their free outer ends. The resulting seam is left open and functions as a conductor receiving slot 34 for the conductors 6.

The tubular conductor receiving portion is divided intermediate its ends by transverse shear lines 36 which extend from the slot 34 diagonally and forwardly down the sidewalls 32 to punched holes 35. As will be explained below, this feature of the preferred embodiment divides the conductor receiving portion 28 of the terminal into two semi-independent spring systems for the accomodation of two or more wires or the accomodation of one relatively coarse wire.

The underside of the conductor receiving portion is cut away at the righthand end thereof as viewed in FIG. 4 so that the upper portions of the sidewalls extend rearwardly, cantilever fashion, beyond the rearward end of the web 30 as shown at 38. This feature is advantageous for the conductor insertion operation as is described in the above-identified application Ser. No. 347,965. It will be noted that the edges of the projecting sidewall portions 38 diverge as shown at 40 (FIG. 5) at the rearward end of the conductor receiving portion. These divergent edges function to guide the wires into the slots 34 while they are being inserted.

Referring now to FIGS. 2 and 3, the cavities 16 in the housing 10 are separated from each other on the mating side 12 of the housing by T-shaped barriers 42. These barriers extend from the floor of the housing partially to the upper wall 43 so that a trough-like recess 58 is provided on the mating side of the housing which is adapted to receive an edge portion of the printed circuit board 4. Each cavity has a floor 44 and a recess 46 is provided in the floor which extends inwardly from the mating side 12. This recess defines a shoulder 48 which is directed towards the mating side 12 of the housing for cooperation with the tang or lance 26 of an inserted terminal. An additional groove 50 extends inwardly in the floor 44 from the rearward side 14 and has an inclined inner end 49. It will be apparent that an individual terminal is mounted in the housing by merely moving it axially into a cavity. The tang 26 will be flexed into the plane of the tongue by the inclined surface 49 but will spring into the recess 46, when the terminal is fully inserted, and lodge against the shoulder 48 to prevent removal of the terminal.

The intermediate portion 51 of the cavity is constricted as shown in FIG. 4 so that the terminals cannot move completely through the cavity and the righthand portion of each cavity which extends to the rearward side 12 of the housing is enlarged to accomodate the tubular conductor receiving portion of the terminal. Openings 54 are provided on the upper side 52 of the housing and have arcuate inner ends 56 as shown in FIG. 5. Finally, the walls between adjacent cavities extend rearwardly as shown at 53 so that the projecting rearward ends 38 of adjacent terminals are separated from each other.

A removable back cover 60 is provided on the rearward side 14 of the housing comprises a backwall or web 62 having forwardly extending flanges 64, 65. Integral latching arms 68 extend forwardly from the ends of the cover and have outwardly displaced free end sections 70 which have slots 72 therein. This back cover can be assembled to the housing by simply locating it in alignment with the rearward side 14 and moving the cover towards the rearward side until the arms move over bosses 74 on the oppositely facing ends 78 of the housing. The edges of the flanges 64, 65 are preferably rounded as shown at 66 to provide curved surface over which the conductor 6 can be dressed. It will be apparent from FIG. 1 that the flange 64 extends partially over the side 52 of the housing and partially covers the openings 54. The wires are thus confined between the flange 64 and the inner ends 56 of the openings 54.

As previously mentioned, the conductor receiving portion 28 of the terminal is capable of accomodating and forming electrical connections with at least two wires. As shown in FIG. 5, where two wires are to be connected to an individual terminal it is desirable to locate one of the wires forwardly of the shear 36 of the tubular portion and the other wire rearwardly of this tubular portion. When the wires are so located, they will each be in one of the spring systems which are provided on each side of the shear 36. This arrangement avoids a concentration of extremely high stresses in a localized zone which would result if two wires are located adjacent to each other in a single slot of a terminal member having only one spring system. As also noted above, the wire receiving portion of the terminal is capable of accomodating a relatively wide range of wire sizes. When a relatively coarse gauge wire is inserted into the slot, it is advantageous to locate this coarse wire at the intersection of the shear 36 and the conductor receiving slot 34 as shown in FIG. 6. If a wire is so located, four zones of electrical contact are established and the two semi-independent spring systems are both active in establishing the contact.

The wires 6 can be inserted into the conductor receiving slots 34 of each of the terminals in the connector by means of an apparatus 80 shown in FIGS. 7 and 8 which is fully disclosed and claimed in application Ser. No. 347,965. This apparatus comprises a base member 82 which is secured to a work surface 83 and which has an inserting tool 95 removably secured thereto. A recess 84 is provided in the upper end of the base 82 and a connector 2 is clamped in this recess with the conductor receiving portions of the terminals upper most by means of a clamping screw 90 which is threaded through a clamping plate 88. A plurality of wire locating vanes or barriers 92 are provided on the upper end of the base 82 and similar barriers 94 are provided on the upper end of the clamping plate 88. These barriers are mounted such that a wire positioned between adjacent barriers will be in alignment with the conductor receiving slot 34 of a terminal as shown in FIG. 7.

The tool 95 which is removably secured to the base 82 has a frame 96 in which a slide member 98 is guided for movement towards and away from the connector 2. An inserting punch means 100 is mounted in a recess 101 in the lower end of slide 98 and comprises a plurality of relatively thin spaced-apart plates, one plate being in alignment with each terminal in a connector. Each plate is centrally notched as shown at 101 so that it can move past the upper end of the terminal as shown in FIG. 8.

Slide 98 has a cam follower 102 on its upper end which is in engagement with a cam 104 mounted on a shaft 105 in the upper end of frame 96. A handle 106 extends from cam 104 and when this handle is swung counterclockwise as viewed in FIG. 7, the slide 98 will be driven downwardly from the position of FIG. 7 to the position of FIG. 8.

In use, after a connector has been clamped in the recess 84 and wires have been located between each pair of adjacent barriers 92, 94 on the upper ends of the frame member 82 clamping plate 88, the handle is swung counterclockwise, the slide 95 descends, and the wire 6 is pushed downwardly. As the wire moves past the edge 108 of a cutting die 110 mounted in the base 82, the edge 112 of the slide cooperates with the edge 108 to sever the wire as shown prior to its movement into the slot 34 of the terminal. Further details of this apparatus and a preferred method of manufacturing harnesses with this apparatus and connectors in accordance with the instant invention are described in application Ser. No. 347,965.

It will be apparent from FIGS. 7 and 8 that as the wire moved downwardly, it is captured and guided by the edges 40 of the terminal towards the slot and, the wire is partially inserted into the slot prior to its being trimmed by the edges 108, 112. The wire is thus fully controlled during the trimming and inserting operation and there is little possibility of the wire being improperly inserted or trimmed.

A salient advantage of a terminal in accordance with the invention is that conductor receiving portions can be formed by a relatively simple, but precisely controllable, die forming operation and it is not necessary to punch a precisely dimensioned slot as is common in prior art devices. As also noted above, a terminal having a tubular conductor receiving portion as described herein is capable of accepting a relatively wide range of wire sizes by virtue of the transverse shears which give rise to two semi-independent spring systems. A terminal having these two spring systems is also advantageous where two wires must be connected to the terminal in that a separate spring system is provided for each of the wires. Finally, it has been found that a very good mechanical connection between the wire and the terminal is achieved particularly, if the wire is pulled in a direction normal to the axis of the tubular portion of the terminal. The back cover of the connector has the effect of orienting the end portions of the wires normal to the axis of the terminal so that any tensile force or pull applied to the wires is transmitted to the mechanical connection in the preferred normal direction.

A connector assembly in accordance with the invention has all of the advantages of a pre-loaded electrical connector as described in application Ser. No. 147,578 and in addition, is particularly advantageous for harness manufacturing methods as disclosed and claimed in application Ser. No. 347,957. It will be apparent that the principles of the invention can also be used for connecting wires to electrical devices other than multi-contact connectors such as switches and relays. It will also be apparent that the principles of the invention can be practiced to connect conductors other than round wires to terminals; for example, to connect the conductors of a flat conductor cable to terminals as disclosed in application Ser. No. 310,056.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only.

Claims

What is claimed is:

1. A pre-loaded multi-contact electrical connector comprising:

an insulating housing having a mating side and a rearward side, said housing having a plurality of contact-receiving cavities extending therethrough from said rearward side, said cavities having openings which open onto one side which is between said mating side and said rearward side,

an electrical contact terminal in each of said cavities, each of said terminals having a contact portion which is proximate to said mating side and a conductor receiving portion which is proximate to said rearward side, said conductor receiving portion being tubular and having an axially extending open seam, said seam constituting a conductor-receiving slot which extends in said conductor receiving portion inwardly from said rearward side towards said mating side, said slot being on the side of said tubular section which is adjacent to said opening whereby,

upon movement of a conductor laterally of its axis into said slot, the edges of said slot will engage said conductor to form an electrical connection therewith, and said conductor, after being connected to said terminal, will extend laterally of said housing from said opening.

2. A pre-loaded connector as set forth in claim 1 and a cover member removably mounted on said rearward side of said housing, said cover member extending over said one side of said housing and partially covering said openings.

3. A pre-loaded connector as set forth in claim 2, each of said conductor-receiving tubular portions of each of said contact terminals being partially transversely severed intermediate the ends thereof and partially therethrough from said open seams.

4. A pre-loaded connector as set forth in claim 2, and conductors in said slots in said conductor receiving portions of at least some of said terminals.

5. A stamped and formed electrical terminal device having two conductors electrically and mechanically connected thereto, said terminal device comprising:

a conductor-receiving portion and a contact portion,

said conductor receiving portion comprising a formed tubular member having a web and sidewalls, said sidewalls having opposed edges extending axially in a straight line along said tubular member, said edges defining a conductor receiving slot, said conductor receiving portion being partially severed transversely of the axis thereof from said edges partially along said sidewalls towards said web whereby said conductor-receiving portions is in two sections, each of said sections comprising a spring system,

said conductors having portions extending transversely of the axis of said tubular member and being in said slot, one of said conductors being in one of said sections and the other conductor being in the other section,

said contact portion extending from said conductor-receiving portion and having means for forming an electrical connection to a further conductor,

said device being of a conductive metal having spring properties whereby, said edges are resiliently urged against said conductors and said conductors are mechanically and electrically connected to said terminal device, each of said conductors being under the influence of a spring system in its respective section.