Aluminium connector targets motorsport and military systems

Paul Boughton
Serge Buechli looks at a new high-strength aluminium connector due later this year.

The M Series connector is designed for motorsport applications and military systems and is being launched by in 2009. Made of high-strength aluminium, this connector is one of the lightest and most compact connector of the Lemo product range. A ratchet screw mechanism enables quick and secure coupling of the connectors.

The connector has two outer shell designs: arctic grip or knurled outer shell (Fig.1.) The arctic grip makes it easy to manipulate while wearing gloves or when the connector is located in a difficult to access area.

Sealing gaskets made of fluorosilicone rubber ensures resistance against hydrocarbons (oil, petrol, etc). The gasket enables reaching an index protection of IP68 according to IEC 60529 (protection against complete continuous submersion in water). These seals are necessary when the connectors are placed in harsh environments (climate, watertightness, dust, etc).

The M series connector also offers an optional special backend for over-moulding cable assembly. Once the connector, cable and contacts are assembled, the connector can be placed into a mould for injection moulding. The over-mould provides strain and flex relief and also increases the reliability of the product if it is manipulated again and again.

The M series is designed for use in military applications for instance in aircraft communications, land vehicles, night vision equipment, simulation or personal battle equipment, wherever the environmental conditions require rugged systems.

The product is also intended for use in automotive applications such as communications, crash test equipment, data logging racing cars or telemetry.

Helicopters and planes are for instance large consumers of connectors, space optimisation is critical for these applications. Connectors require being compact with a high contact density to allow the transit of numerous low voltage signals within large cable bundles.

Finally, all the connectors of the M series are identified with a laser engraved part number and production batch number to ensure entire traceability from the raw materials.

LEMO connectors are tested for vibrations. The connectors are subject to conditions involving vibrations in each one of the three orthogonal axes (X,Y,Z) during 12 hours. According to standard IEC 600-68-2-6 the connector is subject to vibrations at a frequency range of 1Hz up to 2 kHz and must continue to function. The electrical contacts and electrical shield must insure electrical continuity during the entire test, micro cut-offs should last less than 1µs.

Finally a visual exam of the mechanical characteristics confirms that the connector remains fit to function. LEMO M series connectors have been tested up to 15g, but will be tested up to 30g.

One of the engineer's concerns during product designing is the product's life cycle. Is the product designed to have a life cycle of 10 years or more? If so, how is it possible to ensure that additional parts are available in the future? And if a product is once available, LEMO assures production and manufacturing of the same or equivalent product 10 to 20 years after.

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Serge Buechli is Product Manager wth LEMO S A, Ecublems, Switzerland. www.lemo.com