I recently heard about an application question about a light curtain with a small gap at the top of the sensing field, between the last beam in the field and the surrounding structure of the machine. Some concern was raised about the gap and whether or not additional guarding might be needed to close the…
Read MoreInterlocking Devices: The Good, The Bad and the Ugly

Note: A shorter version of this article was published in the May 2012 edition of Manufacturing Automation Magazine. When designing safeguarding systems for machines, one of the basic building blocks is the movable guard. Movable guards can be doors, panels, gates or other physical barriers that can be opened without using tools. Each of these…
Read MoreHockey Teams and Risk Reduction or What Makes Roberto Luongo = PPE

Special Co-Author, Tom Doyle Last week we saw the Boston Bruins earn the Stanley Cup. I was rooting for the green, blue and white, and the ruin of my voice on Thursday was ample evidence that no amount of cheering helped. While watching the game with friends and colleagues, I realized that Roberto Luongo and…
Read MoreRetained fastenings for fixed guards
If you are building machinery that will be CE marked or is subject to the EU Machinery Directive, you need to read this article at MachineBuilding.net This article reviews some of the retained fastenings that are available for use on fixed machine guards, as required by the new Machinery Directive 2006/42/EC and the guarding standard…
Read MoreUnderstanding the Hierarchy of Controls

(Eds. note: This article was originally written in 2011 and was updated in Nov. 2018.) The “Hierarchy of Controls” is one approach to risk reduction that has become entrenched in the Occupational Health and Safety (OHS) sector. There are other approaches to risk reduction which are equally effective but are less rigidly structured. If you…
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