The Swiss watch industry protects the legendary reputation of its watches with the quality label, "Swiss Made." This level of quality can be achieved in terms of production technology only with fast and accurate automation equipment. This led Amax Automation in Burgdorf, Switzerland, to create a multifunctional palletizer, with robotic and handling systems such as the off-the-shelf EXPT delta robot from Festo. According to legislation by Swiss Parliament, the “Swiss Made” label means more than 60% of production costs must come from Switzerland.
This is one of the reasons why the Swiss watch industry is carrying out more and more of the production steps for watches and watch parts in Switzerland. Another reason is that rising wage costs are making the suppliers in low-wage countries less attractive, not to mention the poor reproducibility of parts manufactured manually. There were also quality losses due to the precision-stamped parts being handled as bulk material. This led to more waste and higher cleaning costs.
By producing in its home market, the Swiss watch industry benefits from faster and shorter transport routes and simpler production control. The palletizers supplied by us at Amax ensure accurately sorted precision stampings for further processing, such as electroplating, painting, pad printing and assembly. The high-precision parts are different for each watch model and each brand, and they’re extremely thin, with a thickness in the range of tenths of a millimeter.
The palletizer is fed directly from a stamping press and a cleaning machine (Figure 1). It’s used to place the fragile parts in transport trays, either to go directly to downstream printing equipment or to further heat treatment operations. The equipment is replacing tasks currently done manually in Asia.
The multifunctional palletizer is very flexible and fast. With a throughput of 120 workpieces per minute, it places up to 11 different small parts in six different lattice trays or two different JEDEC trays (Figure 2). The machine is easily reconfigured for different parts by re-teaching points via the control panel and the software.
At the infeed of the machine, the parts are checked to determine whether they’re upside-down. If upside-down, they’re turned to lay face up on the belt before they’re picked by the robots.
The subsequent steps in the assembly process require the workpieces to be placed accurately. Two integrated vision systems and a specially developed turning system ensure that only correctly oriented workpieces are set down. The system is designed to run 63 different part shapes, so significant vision system programming was required.
Difficult to pick and place
During the actual process of palletizing, the parts were placed on a single belt conveyor, run underneath the camera and then moved to the robots. The intelligent vision system SBO...-Q finds the position of the parts on the encoder-tracked conveyor belt and sends the position and angle data to the two EXPT delta robots. The delta robots use a custom vacuum gripper to pick up the parts from the conveyor belt and place them, depending on the needs of the application, in either a lattice tray or JEDEC tray (Figure 3).