Safe touch button design
By Jean Young Gonzalez, Western Regional Editor -- Design News, January 16, 2000
Designed for ergonomics and safety, Rockwell Automation's new Allen Bradley 800Z Zero-Force Touch Buttons use field-effect sensors and microprocessor technology instead of pressure to sense an operator's touch. The zero-force touch buttons feature a contoured surface that mimics the shape of the palm of the hand, eliminating the need to rotate hands or operate a touch button with only a single finger. This ergonomic design helps prevent carpal tunnel and other repetitive stress syndromes. Two independent sensors read the dielectric strength of an object, at a rate found only in the hand, eliminating accidental tripping by rags or metal objects, such as screw drivers. The push button control, says Rockwell, beats out others with capacitive or photoelectric sensors, which are not redundant enough to eliminate single-fault failure, and meets new OSHA standards. A specific fault LED indicator detects faults and shuts down the button.
Automotive companies interested in complying with global ergonomic and safety directives have pushed for state-of-the-art controls that meet international standards. These units are globally rated, meeting IEC, UL, ANSI, OSHA, CSA (Canada) standards. The devices are available in 30.5-mm and 22.5-mm mounting options. "We worked with our customers to develop an operator interface device that would improve productivity as well as operator safety," says Elmar Gillrath, Rockwell Automation's 800Z Product Manager, who found that some operators can make up to 6,000 repetitive motion operations per shift. OSHA reports that repetitive motion injuries cost industry between $20 and $40 billion a year, in workers compensation, downtime and retraining.
For information on zero-force touch buttons, contact Rockwell Automation Response Center, Dept. 0974, 10701 Hampshire Ave. S., Bloomington, MN 55438; Tel: (800) 223-5354.
