Watertight connector redesign

Problem: According to Elkay Electrical, market research indicates that there is an increasing demand for outdoor electrical applications and, with the climate in the UK, waterproof properties are a prerequisite for anything exposed to the elements. Most outdoor electrical connectors use a thread-based fastening system as it is simple to use but, according to Elkay, they can get clogged, damaged or cross threaded. And many versions have shortcomings in price, design or performance – all major factors for the design engineer to consider depending upon the application. Solution: Discarding conventional approaches and starting with a clean sheet of paper, Elkay decided to redesign the humble waterproof electrical connector using price, design and performance as the primary goals of the design brief. The first immediately obvious difference with its new Aqua-Safe connector is the lack of screw thread. The connector uses a snap-fit latch system to provide a positive, discernible engagement. The connector also uses a radial seal which does not require the accurate clamping and continual holding force of an axial design. A single O ring is used in a groove in the male half of the connector. An angled step two thirds of the way down the barrel reduces the internal diameter compressing the O ring radially in the bottom section of the connector. A second compressing section is several millimetres long meaning the connector can be made with relatively wide tolerances which cut costs without jeopardising its sealing capability. Two rings moulded in the male section also act as a seal preventing turbulence and force under spraying conditions reaching the O ring and any water which want to reach the O ring has to displace the air trapped between these two additional rings. Applications: The Aqua-Safe connector has been designed as a platform that can carry a range of other products meaning that its interior can carry a multitude of different components depending upon the application. The use of the same geometry minimises the investment costs of additions to the range and future developments. Connector elements simply slot into the shells and are rotated to lock them. Elkay has also made full use of the design to make spaces for part number, ratings, approval standards, cable sizes, safety warnings, operating instructions and company logos. The rang currently comprises a 3-pole version with a 5-9mm cable capacity. 1 to 8 pole versions will follow with a choice of 8-13mm and 12-16mm cable diameter capacities. Bulkhead fittings are also available in screw and flange versions. Elkay Electrical