Docking systems - a special kind of connector

The term ‘docking systems’ might not mean much to most readers. Perhaps they would think of their laptop, which is placed on to a docking station, or they might think of an airplane that docks.

In industry, however, docking systems play a large role, and the emphasis here is on connectors for transmitting signals, power, high frequency and media. To put it simply, docking systems are restricted-guidance connectors that are inserted automatically. The force can be applied manually, electrically, pneumatically or otherwise.

The following introduces a few examples that ODU has implemented.

Special machine construction: Pick-and-place PCB assembly machine

ODU Mac - the interface between the feeder and machine. In this case, low power levels and signals are transmitted for driving the feeder reels.

In electronics today, printed circuit boards are almost always fitted with components in a fully automatic process. The components are wound on to reels for delivery to the line. The reels are arranged in so-called feeders. A change in the production program, for example, from product 1 to product 2, usually also calls for different components, and feeder 1 is replaced with feeder 2. The interface between the feeder and the machine is the ODU MAC modular connector. The feeder and machine require a pre-guide with a tolerance of less than ±0.6 mm in order to allow the ODU MAC connector to put its own guide to use.

Medical technology: Patient stretcher in magnetic resonance imaging

The picture shows the ODU MAC with pre-guide (pins approximately 10 mm in Ø) and on the opposite side, with connector guide (pins approximately 4 mm in Ø) (No original, because secret due to an NDA).

In medical technology, patients are often prepared for an examination while lying on a patient stretcher. This allows the operational life of, for example, the MRI system to be increased substantially. The switch from one patient to the next can be done very quickly by undocking one patient stretcher and docking the next one. Here again, a specially designed ODU MAC serves as the interface between the patient stretcher and the (MRI) device. ODU built a complete docking unit here, with more than 100 signal contacts and more than 200 coax contacts. The end movement is handled with a hand lever.

Vehicle construction: Electric vehicles

The docking system in the picture above is equipped with signal, power and high current contacts (up to 200 A).
Also with leak-free hydraulic contacts. The docking system guide has been designed to allow a radial offset of ±3 mm and an angular offset of ±5°.

Electric vehicles have been in use for decades, for example, with lead batteries that are charged at night. Meanwhile, batteries are available that are considerably more powerful. One ODU development in this area is fast charge connectors for 400 A /600 V. But the charging time is disturbingly long in any case. This is why the electric vehicle industry is moving towards exchanging the empty batteries in just minutes by using a docking system.

The two docking systems shown allow large tolerances with respect to the radial offset and angular deviations. Other types of ODU docking systems are used in the Transrapid, for example. The purpose here is to connect thousands of plug-in modules.

Testing technology: Testing of injection valves, car radios, cell phones, printers, automotive electronic systems, etc.

The picture shows the injection valve on the test rack, the black adapter connector for connection to the valve and the ODU MAC for automatic docking to the test computer.

Mass-produced electronic products must be tested. To do this, the products = test pieces are often placed on racks in a decentralised area and then connected. The connection ends in an ODU MAC connector (see red cable) on the rack (usually a header). The racks run on a conveyor past a central test computer. The mating component of the ODU MAC (usually a socket piece) is at this computer. The process runs as follows: conveyor advance - stop - dock rack 1 - test - undock rack 1 - conveyor advance - stop - dock rack 2, etc. When testing mass-produced products, often there is an extremely high number of mating cycles (many hundred thousands in a year), so that the ODU MAC with quick-change head may be advisable here. This makes it possible to replace the insertion side within 1 minute, with no need for cabling changes.

Small, series docking connector (ODU MINI-SNAP series).

Summary: Docking systems often require very complex connectors with very different contacts. Often a large number of mating cycles are called for - between 10,000 and 1 million in a year. The docking solution depends on the guide that is selected. Operation is very often handled with compressed air (in testing situations), but also manually (via a lever) or electrically. For particle accelerators, ODU has built docking systems with dimensions of 1 x 2 m; for charging portable terminals, there are small, stockable docking connectors with diameters under 10 mm.

For more information visit www.clarke.com.au/odu.html.

Reprinted on behalf of CSE with the kind permission of ODU.