This invention is directed to an apparatus for installing twist-on wire connectors onto the ends of stripped electrical wires. The invention also concerns a twist-on wire connector whose shape has been optimized for use with the applicator of the present invention.
Twist-on or screw-on wire connectors have been used for many years to provide a simple and efficient means of mechanically and electrically joining stripped ends of two or more electrical wires. Such connectors typically have a frusto-conical housing or shell with a metallic spring disposed in the interior of the shell. The process of installing one of these twist-on wire connectors usually includes the step of first stripping the insulation off the ends of a number of wires. Next, the twist-on wire connector is placed onto the stripped ends of the wires. Once the connector is in place, it is rotated or twisted, typically by hand, until the wires are joined together. As a result of this process the electrical wires are electrically and mechanically joined, with the outer insulating shell of the connector providing protection for the stripped wire ends.
Many twist-on wire connectors include opposing, outwardly-extending wings or fins to provide a comfortable and accessible surface to facilitate twisting by hand. However, applying large numbers of these connectors by hand can lead to fatigue or repetitive stress injuries. Furthermore, the several steps involved in terminating or connecting wires makes the process slow and inefficient where numerous connections need to be made.
Devices have been made to address the need for repetitive twisting motion. These devices, which may be referred to as “twist assist” devices, have a conically shaped cup which receives the wire connecter's shell. At the other end of the twist assist device there is an axially-extending shaft, which is inserted into a driver of some sort. The driver can be either a hand-operated tool or a powered drill or screw-driver. While these twist assist devices address the problem of repetitive motion injury, the many steps still required to apply connectors keep the process relatively slow and in need of improvement in production situations where large numbers of connectors have to be applied.
Other devises are also known for attaching twist-on connectors. One such apparatus is shown in U.S. Pat. No. 3,016,774 to Minobe, the disclosure of which is herein incorporated by reference. It includes a receptacle or hopper for holding a large number of twist-on connectors. The connectors are serially fed from the hopper through a tube or semi-flexible hose to the hand-operated applicator. A switch initiates the rotating motion to apply the connector onto the stripped ends of the wires. Devices of this type are typically used at a fixed workstation in an assembly line operation.
While this type of apparatus addresses repetitive stress problems and helps to speed up the process of applying connectors by automatically feeding a new connector to the applicator, these devices are bulky and not easily transportable. In addition, these devices cannot assist tradespeople who quickly move from one location to another. While the twist assist drivers mentioned above are fully portable, they operate on only one connector at a time. What is still needed in the art is a device, which combines the advantages of serially feeding connectors and with the portability of hand-held twist assist drill/drivers.