Power Driven Wire Nut Wrench

This invention is related to wrenches used to apply helical spring type wire connectors commonly known as Wing Nuts or Wire Nuts, and more particularly to wrenches for wire connectors that are used with power tools.

Spring loaded fasteners are used in electrical work to connect wires together. These fasteners have a conical shape and have either flanges or ribs that a worker can grip while the connector is applied. These devices are a big improvement over solder and tape splices and come in a variety of sizes. Spring loaded wire connectors have one major problem, however, their size tends to cause hand cramps and muscle fatigue after repeated installations. Proper connection torque is also difficult to achieve when many wires are connected together. To alleviate these difficulties, connector wrenches have been developed to make using the devices easier, and to ensure that all connections are properly torqued. One example of this type of wrench is found in U.S. Pat. No. 3,787,948, which discloses a wrench having an oblong head piece that has an opening sized to fit a typical wing type connector. A handle extends from the opposite end of the headpiece from the connector opening. The handle has a ratchet to allow the entire headpiece to rotate around the connector axis while the connector also rotates, thereby tightening the connector onto the wire. This device has several problems. First, the handle is offset from the opening, which makes the device awkward to use. Further, it is hard to obtain proper leverage to make a tight connection because of the thin handle.

Other devices include a small wrench device that is designed to accommodate two different sized connectors. This device is ovoid in shape, and has two connector receptacles placed side-by-side in the base. This device is small and must be held by the fingers, much like a wire connector. This device, therefore, will cause the same hand cramps with repeated use as do the connectors. Also, its small size makes it difficult to obtain good leverage to make solid connections when used on heavy gauge wires.

Another device is simply a screwdriver that has a hole drilled in its base that is sized to fit a connector. Although this device has some advantages over the others, is also has a metal blade extending from the opposite end. This produces a potential safety problem if the device is used around live electrical circuits. Also the blade could cause injury when the device is being used. The latter devices are produced by Ideal Industries, Incorporated, Sycamore, Ill. All of these devices are intended to be used manually. The present invention is a device that is intended for use with power tools such as power screw drivers or variable speed drills.

The present invention consists of a clear plastic housing that has good dielectric properties. The housing is tapered inwards toward the bottom of the housing, forming a generally conical shape, and is hollow on the inside. Wire connectors are placed within the hollow interior of the housing through the top of the device, which is open. The housing has two, oppositely disposed slots which are used to receive the flanges typically found on wire connectors. The housing also has a series of ribs placed concentrically along the inner wall of the housing. The ribs are used to engage a similar set of ribs found on certain types of wire connectors.

A shaft is attached to the bottom of the housing. The shaft can be round or hexagonal and is inserted into the chuck of standard power tools such as variable speed drills or power screwdrivers.

A magnet is embedded within the bottom of the housing. The magnet is used to attract and hold the spring typically found in all spring loaded wire connectors, once the connector is inserted into the housing.

It is the object of the invention to provide a power driven wire nut wrench for use with all types of wire connectors.

FIG. 1 is a side view of the invention.

FIG. 2 is a top view of the invention along the lines 2--2.

FIG. 3 is a detail of one type of connector.

FIG. 4 is a detail of a second type of wire connector.

FIG. 5 is a detail of a third type of wire connector.

FIG. 6 is a detail view of a typical wire connector inserted in the device prior to use.

FIG. 7 is a detail view of a hexagonal shaped shaft, which is an alternative shaft design.

Referring now to the drawing figures, and more particularly to FIG. 1, the invention consists of a clear, high impact plastic housing 1. Although the housing 1 is clear plastic in the preferred embodiment, it can be manufactured from any similar lightweight, non-conductive material. The housing 1 is fastened to a shaft 2 by either sonic welding, embedding the shaft in the plastic housing, or other means known to the art. In the preferred embodiment, the shaft 2 is hexagonal in shape to provide a stronger gripping surface within the power tool's chuck. However, the shaft 2 can also be cylindrical or any other form common to the art. A magnet 3 is also embedded within the housing, at the shaft end, as shown in the drawings. The magnet 3 is designed to attract and hold the helical spring that is placed in all of the type of wire connectors that this device is intended for (see, e.g., FIG. 4). The housing 1 has two slots 4 and 5, placed on opposite sides of the housing 1 as shown. The slots 4 and 5 hold the flange portion of the connectors (see FIGS. 3, 4, and 6). A plurality of ribs 6 are spaced equally around the inner wall as shown. The ribs 6 run the length of the housing 1 and are designed to hold the type of connectors found in FIG. 5, which have no flanges, but are ribbed to provide a gripping surface.

Referring now to FIGS. 3, 4 and 5, wire connectors are produced under a variety of trade names and have three main designs:

FIG. 3 shows a connector 20 that has a soft plastic coating and two protrusions, 21 and 22, that extend from the middle portion of the connector body. FIG. 4 shows a second type of connector 30 that has a hard plastic shell. The shell has two wings, 31 and 32, that extend from the base of the housing. This figure also shows that helical spring 33, which is installed in all types of these connectors. FIG. 5 shows a third type of connector 40 that has no protrusions or wings. This connector has a hard plastic shell and a plurality of ribs 41 to provide a gripping surface for the connector's intallation.

The device is used by inserting the shaft 2 into the chuck of a standard power screwdriver or variable speed drill and then locking the chuck around the shaft 2. A wire connector of any type is then inserted into the housing until it is firmly seated (see e.g., FIG. 6). The wire connector is then placed over the bared ends of the wires to be connected and the power tool is activated, which rotates the connector around the wires until the connection is complete. The power tool can then be pulled directly off of the connector and the housing 1 is then ready to receive another connector.

It is intended that the present disclosure should not be construed in any limited sense other than that limited by the scope of the claims having regard to the teachings herein and the prior art being apparent with the preferred form of the invention disclosed herein and which reveals details of structure of a preferred form necessary for a better understanding of the invention and may be subject to modification by skilled persons within the scope of the invention without departing from the concept thereof.