During the past several years, connectors have become smaller, lighter and fashioned out of new materials and material combinations. Naturally, connector backshells have followed suit. These backshells, including strain reliefs, cable clamps, adapters, and more, that are threaded onto rear-connector accessory threads, are part of the complete connector assembly.
Shedding weight is accomplished by moving from heavy materials to composites with sufficient strength and durability. Polymers and aluminum are gaining ground in assisting the quest for the overall decrease in device weight. The weight reduction achieved with these materials results in no temperature or fluid-resistance performance penalty.
TE Connectivity’s AMPSEAL 16 Connector System, the 2035047-1, targets off-road, heavy-duty industrial, recreational and agricultural applications. The wire-to-wire and wire-to-device connector line meets rigorous industrial demands and extremely high-performance standards. Thermoplastic housings (-40 C to +125 C rated) and silicone seals allow the connectors to withstand extreme temperatures and moisture.
Figure 1: The AMPSEAL connectors from TE Connectivity provide rugged reliability and easy-to-use advanced environmental sealing for heavy-duty applications. (Source: TE Connectivity)
The connector system features the HDSF size-16 pin and socket contacts as a terminal system. The contacts are stamped-and-formed versions of the screw-machined MIL-C-39029 contacts. The housing offers one-piece assembly for plug and cap.
The TE Connectivity 1-1355928-2 90-degree polybutylene terephthalate box backshell is designed for use with socket housings, X-1355929-x and x-1355930-x. It features 54 positions and has a cable-exit angle of 90 degrees. It is used for high-intensity discharge headlamp sockets. Components for the system include an HID-socket-housing moving plate, housing cover—twist locking with lamp and shield ring. It provides superior electromagnetic compatibility and electromagnetic interference (EMC/EMI) shielding performance and is easily installed, maintained and repaired.
Other design modifications in addition to materials are also providing lighter solutions. Cross-linked insulation and jacket materials, for example, are providing weight reduction, thinner walls, as well as abrasion, solvent and chemical resistance, even when used in high-temperature applications.
Figure 2: Mil-Spec cable assembly. (Source: Rugged-Portable)
It’s not always a matter of replacing metal as a material that is the selection goal. Often, the focus is on miniaturization. This is true, for example, with the SDH-9BF 180° metal backshell by Cinch Connectivity Solutions for D-subminiature connectors. Backshell length in this design is 37.34 mm, with a depth of 47.24 mm and height of 20.83 mm. The Cinch Super D Interconnection System represents a simple, fast, economical and reliable means of mating cable-to-cable or cable-to-panel connectors. Within the system, snap-on super-D plastic hoods provide positive, self-latching and audible mating that has a reliable retention and a quick release. The Black SDH backshells accommodate any standard metal-shell IDC, solder cup, or crimp and poke D-subminiature connector.
Backshell selection can be daunting, given today’s complex designs and evolving assembly procedures. Considerations include connector type, cable- or wire-bundle diameter and makeup, application environment, restrictions on size, shape or weight, and the desired performance. Strain relief, water resistance, moisture resistance, shield termination, the working room available in the design, and the ensuring of product performance to a variety of standards, are also challenging.