Manufacturing has evolved over the years to where factory workers of merely a generation ago would find it hard to recognize the cleanliness, efficiency, and increased safety at many of today's most up-to-date manufacturing facilities.
Yet many manufacturing processes remain inherently dangerous. Molten steel is poured and cast, sheet metal is stamped, shaped, and cut, and flaming gases or intense bursts of electricity are used to weld parts and components into assemblies.
CenterLine Ltd (Windsor, ON, Canada) has been involved in moving manufacturing forward for years. Celebrating its 50th anniversary in 2007, CenterLine supplies welding guns, electrodes, and other industrial products worldwide. The company's Special Machinery Division designs and manufactures custom automated welding and metal fabricating equipment for a variety of industries, among them automotive, mass transit, appliance, and aerospace. Many of its product and process developments have become industry standards.
Focus on Safety and Efficiency
Safety and efficiency are paramount. Not only does CenterLine work with its manufacturing customers to design and build equipment, it is responsible for machine installation, startup, and training assistance at the customer's plant.
"A custom welding machine contains a number of safety devices, including E-stops, light curtains, and safety gate switches, all designed to protect operators and other personnel on the plant floor," says Dan Dinunzio, controls manager for Centerline's Special Machinery Div. "We were looking for a programmable device to not only monitor processes, but to replace 8-10 safety relays. This would make the equipment easier to configure and also require less wiring in the control box."
After surveying the field, Dinunzio selected the PNOZmulti modular safety system from Pilz Automation Safety (Canton, MI). The system consists of a base unit that includes a chip card that communicates with various safety devices while also being readable to plantwide bus systems such as DeviceNet or, where safety is concerned, Pilz's SafetyBUS p (which is in the process of refocusing into SafetyNET p, using Ethernet as the standard). Safety and standard control functions are configurable through 20 inputs, 4 semiconductor outputs, and 2 relay outputs. The base unit is simply attached to a control box's top rail and wired up. Users can save more than 40% of engineering, installation, and maintenance time and costs.
System Benefits
"Our benefits are that we are able to replace between 8 and 10 safety relays in every machine we build, so there's less wiring and less hardware, which translates into cost savings," Dinunzio says. "It's child's play to operate, making configurability a simple matter of drag-and-drop on a PC. And if an automated welding machine ever needs to be retooled, ease of changing configurations is a real time-saver."
Overall, the benefits to CenterLine as a custom machine builder equate to shorter engineering and installation times while achieving unquestioned security in monitoring all safety requirements.
"We did the analysis, and Pilz was perfect for our application," Dinunzio says.
