"Ooni lüüt gaat nüüt" is the sound of success at Phonak AG (Stäfa, Switzerland), a hearing aid manufacturer. The company’s products require challenging manual assembly processes. The company looks for flexibility, ergonomics and user-friendliness when selecting assembly equipment. Workstations and TS1 conveyors from Bosch Rexroth Corp. (Buchanan, MI) meet these requirements.

"Ooni lüüt gaat nüüt," when loosely translated, means "no people, no progress." And in today’s assembly environment, this phrase has taken on greater significance.

Short production cycles, small lot sizes and a large number of product variations are typical. It’s also common to find an increasing number of complex assembly processes, which are either impossible or prohibitively expensive to automate. As a result, manual workstations are often the most adaptable and economical means of production.

When the company introduced its "Claro Hearing Computer," a completely digital, computerized hearing aid, it began looking for ways to optimize the new product’s manufacturing methods, starting with an evaluation of the existing, more traditional processes. And Phonak invited its employees to participate in the earliest stages of the selection process.

In the existing manufacturing process, workpieces were shuttled from station to station using magazine containers. Each container carried up to 100 parts holders, with one hearing aid or electronics assembly per carrier. This meant that 99 hearing aids, each one step further in the assembly process, might have to wait for the 100th unit before they could move to the next step.

Now, an automated conveyor system is used for assembling the devices. With the new process, workpieces travel through 16 cycle-independent assembly stations, linked together by a TS1 conveyor. Work processes occur in parallel, and material throughput times are considerably reduced.

The TS1 is a compact conveyor system. With workpiece pallets weighing up to 3 kilograms, in sizes of 80 by 80 millimeters to 160 by 160 millimeters, and repeatability of ± 0.015 millimeter, the TS1 system is especially suited for the transport of small products and assemblies.

The workstations also consist of Bosch components. The basic setup is a workstation and swivel chair, along with material shuttles, parts bins and information boards for work instructions.

Concept and realization of the complete assembly system was carried out by FMS-Technik AG in close cooperation with Phonak. (FMS-Technik is the Bosch Rexroth sales partner in Beringen, Switzerland.) FMS-Technik supplied a prototype workstation. The sample workstation allowed the workers to try out and test the systems that were being considered. "Making use of the knowledge we gained during these evaluations played a crucial role in the quality of the new hearing computer line," says Mathias Böni, an engineer from the Phonak project team.

Because the workstations and transfer systems are modular, it is easy to mount individual accessories, such as special armrests and microscopes, at the most ergonomically appropriate location. Another advantage of the system is that the workstations and transfer systems are not directly attached to each other. This eliminates any possible vibration transfer, which is absolutely critical for all work processes requiring microscopes.

It is also important to prevent electrostatic discharge (ESD) in the final assembly area. Due to the electrical properties and the hearing aid design, the sensitive electronics in the hearing aids can be damaged or destroyed by ESD. Therefore, the workstations and conveyors are ESD-safe.

With the TS1 conveyors and workstations, Phonak has successfully implemented an assembly line that meets all of its requirements. Throughput times have been dramatically reduced. At the same time, enough flexibility has been created to economically produce small lot sizes.

The TS1 transfer system has rapidly shown itself to be the ideal solution for automating parts transfer at Phonak, thus also helping to achieve progress for the "people."

For more information on workstations and conveyors, call 800-739-7684 or visit http://www.boschrexroth.us.com.