More reliable than adhesive bonding, and more consistent than ultrasonic welding, this laser welding system provides a joining process for composite car keys which is fast and cost effective.
Molded in the same glass fiber polyamide material, the key's two halves contain different pigmentation. Consequently, the laser beam passes directly through the top half without any effect, but is absorbed by the lower part, causing its temperature to rise. First, the lower surface melts, then the upper surface.
The result is a join which is invisible from the outside, but which is completely waterproof. Cycle time for the 120 mm join on each key is approximately seven seconds.
| A robot arm guides the 200W laser beam around the two key parts with aid from an inclined mirror. An infrared sensor, mounted on the arm, monitors joint-line temperature and continually adjusts laser power for consistent quality.
Albert Hiller, HUF Tools GmbH, Tel: +49 2051 272 222, Fax: +49 2051 272 555.
Multi-shot stack molding typically requires large platens to incorporate a turntable; hence an oversized machine that becomes more impractical as part size increases. A pivoting center platen replaces turntables used in multi-shot molding to reduce machine size, make the process practical for larger parts, and maximize part-making productivity.
Overmolding starts with the preform injected into the cavities on one mold face. As the mold opens, the center platen swivels 180į in a vertical plane, then locks into position. The mold closes, and the second material component is injected.
| A two-sided center platen, with two mold-mounting faces, permits two simultaneous molding operations in one machine and cycle.
Tom Jarold, Milacron Inc., 4165 Halfacre Rd., Batavia, OH 45103; Tel: (513) 536-2428; Fax: (513) 536-2441.
A single Type NM safety switch accommodates four different lateral approach directions, and one approach direction from the top. Its multiple-position design is reported to be quick and easy to set. Changing the approach direction requires pulling out the actuator and bridge, flipping down the hinged cover, and rotating the sensing head to the desired orientation.
Three cable entries, lateral and bottom (Type NM12) and a choice of actuators (straight or bent) add to switch flexibility. The design features large-sized connection terminals for each contact element, and offers a choice of dependent action contact switching elements: one positively driven NC or two positively driven NC + 1 NO.
A reinforced thermoplastic housing helps the safety switch achieve IP67 (IEC 529) environmental protection. The small and lightweight (.08 to 0.1 kg) safety switch fits in compact assembly equipment, material handling, and general automation systems
| Type NM safety switches offer engineers design flexibility with easy setup for multiple approach directions.
. Mercel Ahearn, Euchner USA Inc., 300 Round Hill Dr., Ste. 4, Rockaway, NJ 07866; Tel: (973) 586-2600; Fax: (973) 586-1590.