Insulation Piercing Contacts and Connectors

1. Field of the Invention

The invention relates to electrical contact members and electrical connectors and particularly to contact members employing insulation opening or penetrating means which are enabled to complete electrical connections when an insulated conductor is installed in the contact member. More particularly, the invention relates to an electrical contact member including a tube incorporating means enabling an insulated conductor to be threaded through the hollow interior of the tube and through the wall of the tube into contact with insulation opening means to enable completion of electrical engagement between the conductor and the contact member.

2. Description of the Prior Art

Among the prior art electrical contacts and connectors which incorporate means for opening or penetrating insulation of insulated conductors to expose the underlying conductor are devices, such as that shown in U.S. Pat. No. 3,147,058, which include insulation severing slots arranged in a cylindrical body to cut insulation around an insulated conductor and establish electrical engagement with the conductor. In this known art the insulation opening slots terminate in an open extremity at one end of the contact and the insulated conductor is introduced through that open extremity. There is no provision in this prior art for admitting the insulated conductor through the wall of the contact and no way in which the conductor may be twisted around the slot and through the contact.

Other prior art connectors include a family of connectors which are formed of two or more distinct parts. In connectors of this character, one part generally receives the insulated conductor and the parts are then closed together to sever the insulation, establish electrical engagement and secure the conductor to the connector. Clearly these devices do not anticipate the one-piece contact member exemplary of embodiments of the present invention.

Accordingly, it is an object of the present invention to provide an improved arrangement to enable connections to be completed between electrical contact members and insulated conductors. A further object is to provide one-piece contact means incorporating inlets to receive insulated conductors and insulation opening means to complete connections between the conductors and the contact means. Another object is to provide insulation opening means integral to the wall portion of a contact tube and intermediate the ends of the tube. Yet a further object of the present invention is to provide an improved contact member which may be fashioned as a unit to make it possible to sever insulation of an insulated conductor, complete electrical connections and provide a strong mechanical linkage between the conductor and the contact member. Still another object is to provide contact members formed of a plurality of one piece insulation opening and contact means. Yet another object is to provide a one piece contact tail incorporating tubular end and side openings serving as inlets and outlets for insulated conductors and incorporating means for piercing insulation to complete electrical engagement between the contact tail and an insulated conductor. Still another object is to take advantage of tubular construction by providing an axially extending slot intermediate the ends of the tube such that the slot is strengthened against being enlarged by stresses during installation of a conductor. A related object is to provide reinforcement to a slot over that provided by a flat blade construction employing metal of equal strength.

To attain the foregoing and ancillary objects, one or more contact members are employed in which each contact member is formed as a tube provided with conductor receiving means closed ended at axially opposite locations along the tube and including insulation opening means with a slot radially extending through a wall portion. At one end, the slot is provided with tapered edges spaced apart to penetrate and separate insulation on an insulated conductor to expose the underlying conductor and elongated edges to engage and establish electrical engagement with the metallic conductor. The slot is terminated at the elongated edges by a closed end and at the opposite end is continuous with an entry opening through the wall portion of the tube to permit the insulated conductor to be inserted through the wall and moved transverse to its axis into the slot for insulation opening and electrical engagement with the edges of the slot. The entry opening at its end opposite the slot is also closed ended and bounded by a continuous peripheral portion of the tube.

To utilize the invention, the insulated conductor is passed through, or threaded through, both the entry opening and the open end of the tube and is then pulled into engagement with the insulation opening edges of the slot to sever the insulation, after which the conductor is pulled into electrical engagement with the elongated edges of the connector slot and thereby into electrical engagement with the connector. The tube may then be crimped to increase the strength of the mechanical connection between the connector and the conductor. In practice, one or more contact members may be mounted in insulating bodies to form a connector.

The above mentioned and other features and objects of this invention and the manner of obtaining them will become more apparent, and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, in which

FIG. 1 is a perspective view of an embodiment of the invention showing an insulated conductor, or wire, installed in a slot in a tube,

FIG. 2 is a view of the embodiment of FIG. 1 in partial section showing an insulated wire secured in the slot,

FIG. 3 is a plan view of an embodiment of the invention showing an installed wire in section,

FIG. 4 is a sectional view along line IV--IV of FIG. 3, and

FIG. 5 is an elevation in partial section of an exemplary connector according to the invention.

Turning now to FIG. 1, a contact member or connector for use in the invention is shown at 2. This connector may be formed of sheet metal which is bent to form a tube having a seam (not illustrated). Alternatively, the connector may be formed from seamless tubing which is cut into tubes of suitable length for increased rigidity. Pin contact members such as that illustrated at 3 may be employed to complete connections to sockets (not shown). Alternatively, a socket may be substituted for the pin 3 enabling connections to be completed to pins which are not illustrated.

To prepare a tube to serve as a connector between a pin 3 or other contacting device and an electrical conductor, the individual tube is punched, or otherwise cut, to provide a hole, or opening, at 4. The hole is cut to a size suitable to permit an insulated conductor of prescribed diameter to pass through in a direction either into or out-of the tube. Piercing edges at 11 and 13 are formed to pierce the insulation 16 and prepare the conductor 18 to engage parallel edges 10 and 12 of the slot 14.

The entry opening and the slot though the wall of the tube are arranged so that they are surrounded by the wall portion with the advantage that the edges of the opening and of the slot are held to reduce their spreading apart or bending. The tube in this way prevents the wall portion of the slot from either spreading apart or bending, and thus decreasing the effectiveness of electrical connections more. It will be seen also that a slot bounded by a tube is far more resistant either to spreading apart or bending than a slot formed in a flat surface or a slot formed by separate flat surfaces formed from the same weight and of metal.

To facilitate assembly of the insulated wire into the tube, a flap 6, as an entry ramp, which in a preferred example is formed from the wall portion of the tube, is pushed into the tube as is shown most clearly in FIG. 2. Thereafter, when an insulated conductor is pushed into the tube, either through the entry opening 4 on the side of the tube or the opening 8 at the end of the tube, the wire is deflected by the flap 6 to exit through the other opening. In this way, the insulated conductor and the connector are positioned so that they then may be interlocked and electrically interconnected.

After the insulated conductor has been placed in the tube, as shown by the sectional outline of the insulated conductor at 16 in FIG. 2, the conductor is pulled against cutting surfaces at 11 and 13 which pierce the insulation 16 to enable electrical engagement to be established between the conductor 18 and the walls 10 and 12 of the slot 14, as indicated further in FIGS. 2 and 3. The tube may then be crimped, as at 19, by a crimping tool to secure the conductor and the connector together.

As is indicated in FIGS. 1-4, the flap 6 may be formed from the wall of the tube 2. It may be pressed down in a preferred embodiment at an angle of 45 degrees to the central axis of the tube. Set at this angle, the flap will deflect insulated conductors which are pressed into the tube through either opening. However, the flap will serve as a deflector when set at other angles and, in fact, may serve better as a deflector under some circumstances when set at some other angle. This flap may be circular, elongated, or have some other shape, if desired.

A contact member, or a plurality of contact members, may be housed in suitable individual compartments in an insulator body to form a connector. An example of such a connector is illustrated in FIG. 5, wherein a plurality of contact members 2 are shown in compartments of an insulated body which isolate them electrically from each other and hold them in place. In this example, each contact member 2 is connected electrically to the conductor portion on insulated conductor 20 which is part of a multiple conductor at 22. The insulated portion of each conductor is secured to its contact member 2 and then to the connector 24 by a crimp indicated by a circle at 26. The finished connector 24 may be connected to or separated from a suitable female connector (not shown) without requiring further attention to the individual conductors 2 or pins 3. The pins 3, may be replaced with female or other kinds of connectors without departing from the spirit of the invention.

While the principles of the invention have been described above in connection with specific apparatus and applications, it is to be understood that this description is made only by way of example and not as a limitation on the scope of the invention.