Gender of Connectors and Fasteners - Genderless (hermaphroditic) Connectors

Genderless (hermaphroditic) Connectors

By definition, a hermaphroditic connector includes mating surfaces having simultaneous male and female aspects, involving complementary paired identical parts each containing both protrusions and indentations. These mating surfaces are mounted into identical fittings which can freely mate with any other, without regard for gender (provided that the size and type are already matched). Alternative names include hermaphrodite, genderless, sexless, combination (or combo), two-in-one, two-way, and other descriptive terms. Several of these latter alternate names are ambiguous in meaning, and should not be used unless carefully defined in context. True hermaphroditic connectors should not be confused with mixed gender connectors, which are described elsewhere in this article.

Another closely related type is the stackable connector for electronics, which typically has male pins on one surface, and complementary female sockets on the opposite surface, allowing multiple units to be stacked up like plastic milk crates. Examples of this include stackable banana plugs, and interconnect cables specified for the IEEE-488 instrumentation bus. Stackable mezzanine bus connectors are used on some modular microcomputer accessory boards for systems such as the Arduino add-on daughterboards called "shields". The older PC/104 embedded PC modules use a similar stackable format for interconnection. Stackable connectors are not classified as hermaphroditic in the strictest sense, but are often described as such in looser usage.

The hermaphroditic design is useful when multiple complex or lengthy components must be arbitrarily connected in various combinations. For example, if hoses have hermaphroditic fittings, they can be connected without having to pull a lengthy hose and reverse it because it has the wrong gender to connect to another hose. Some military fiber optical cables also have hermaphroditic connectors to prevent "wrong gender" connector problems in field deployments. In a similar fashion, railcars are usually equipped with hermaphroditic railway coupling mechanisms that allow either end of the vehicle to be connected to a train consist without having to turn the railcar around first.

In the absence of genderless connectors, gender changer fittings might be used to enable certain connections. The designer of a connection system may use one or both schemes to allow arbitrary connectivity, or even combine both schemes into a single system.

When an enforced sense of unidirectionality or "one-way flow" is required for safety or other reasons (for example, AC electrical power connections), a strict assignment of connector genders is implemented to prevent undesired configurations, and gender changers are banned.

Some commonly seen examples of hermaphroditic connectors include the SAE connector for 12VDC power, jackhammer air hose connectors, and the Anderson Powerpole series of modular high-current power connectors. The IBM token ring connector was another widespread example, but it has become obsolete and is being phased out. The General Radio Corporation (GenRad) developed a hermaphroditic coaxial radio frequency connector often called the "GR connector".

Some audio multicore cables are fitted with hermaphroditic multipin quick-disconnect connectors for ease of use in the field. One style of this audio signal cable is fitted on both ends with connectors that are each populated half with pins and half with sockets. The advantage to the user is that it does not matter which end connects to the stage and which to the audio mixer, facilitating faster set up. Another style of connector uses hybrid male/female pins with a receiving slot fitted in the center of each two-tine pin, and relies on 90-degree rotation of the pin axes to mate. The connector housings themselves are sexed male and female.