Packaging
GuardShield Type 4 Safety Light Curtain Helps Improve Safety and Productivity with Muting function for Material Pass-Through
Friday 02. May 2008 - The new Allen-Bradley Guardmaster GuardShield PAC Type 4 Safety Light Curtain from Rockwell Automation helps improve both safety and productivity with a muting function that allows objects or materials - but not personnel -- to pass through the GuardShields sensing field without stopping the machine process.
A development towards functional safety, the muting function is generally employed in conveyorised
processes. It is provided by a muting relay and sensors; when the input conditions to the sensors are met, the relay controls the outputs of the GuardShield PAC and allows the machinery to continue to operate as the material interrupts the sensing field and passes into the machine process. However, if the machine operator is detected due to the muting conditions not being met, then the machine is stopped.
The GuardShield PAC is a multiple beam, short range (0.3 to 16 metres) Type 4 safety light curtain. It is a general-purpose presence-sensing device, designed for use on hazardous machinery, providing point of operation, as well as perimeter and access guarding. The mode of operation is generally as an opto-electronic fence, and when used with corner mirrors the GuardShield PAC can provide two or three-sided detection around the perimeter of hazardous machinery.
GuardShield PAC safety light curtains can be used on any machinery where a formal risk assessment has determined that a Type 4 (per EN 61496) safety device is sufficient to provide the level of safe-guarding required by the application. In addition to conveyors, a list of such machinery would typically include palletizing systems, robotic welding cells, spray booths, automatic processing machines, shrink wrap machines and automated assembly lines.
The GuardShield Type 4 offers OEMs an unequalled package of competitiveness, reliability, durability and flexibility. Providing high levels of ingress protection, to IP65, and housed in a uniquely styled housing, the GuardShield PAC is suitable for guarding applications across a wide range of industries.
In addition, it is relatively simple to install, via M12 Quick Disconnect connectors, reliable in operation, is TUV and CE marked for conformance to all applicable directives, and holds UL 61496 and UL 1998 approvals.
Offering the flexibility of several modes of operation, including beam coding, external device monitoring and start/restart interlock, the GuardShield PAC is an advanced and cost competitive “two-box” design. It supplies multiple safety beams in a range of protective heights to 810mm, with either 14mm or 30mm resolutions, and delivers fast response (210ms) across a wide scanning range of 0.3m to 16m. The GuardShield PAC can be used in standalone mode for personnel detection or with an external muting device; it provides the benefits of low voltage 24v operation, and has been extensively tested against the effects of vibration and shock in operation.