Machinery Safety 101
29 May, 2015

Presence Sensing Devices – Reaching over sensing fields

by Doug Nix
in Canada, Guards and Guarding, Hierarchy of Controls, Ontario, Robotics /
No Comments
This entry is part 2 of 7 in the series Guards and Guard­ing

I recently heard about an applic­a­tion ques­tion related to a light cur­tain where a small gap exis­ted at the top of the sens­ing field, between the last beam in the field and the…

Read More
1 June, 2012

Interlocking Devices: The Good, The Bad and the Ugly

by Doug Nix
in Canada, CE Mark, Components, Control Functions, Control Reliability, EU European Union, EU Robotics, Guards and Guarding, Hierarchy of Controls, Interlocks, Interlocks, International, International Robotics, ISO 13849, North American Robotics, Ontario, Robotics, USA /
11 Comments
This entry is part 1 of 7 in the series Guards and Guard­ing

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…

Read More
21 June, 2011

Hockey Teams and Risk Reduction or What Makes Roberto Luongo = PPE

by Doug Nix
in Canada, Control Functions, EU European Union, General, Guards and Guarding, Hazards, Hierarchy of Controls, International, Risk Assessment /
10 Comments
Canucks Hockey Flag
This entry is part 2 of 5 in the series Hier­archy of Con­trols

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…

Read More
2 March, 2011

Retained fastenings for fixed guards

by Doug Nix
in CE Mark, EU European Union, Guards and Guarding /
No Comments

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…

Read More
28 February, 2011

Understanding the Hierarchy of Controls

by Doug Nix
in Canada, CE Mark, Complementary Protective Measures, Control Functions, Control Reliability, Emergency Stop, EU European Union, Functional Safety, General, Guards and Guarding, Hazardous Energy Control Procedures, Hierarchy of Controls, Interlocks, Interlocks, Lockout, Ontario, Risk Assessment, Robotics, USA /
8 Comments
The Hierarchy of Controls illustrated as an inverted triangle with each level of the hierarchy written one above the other, starting with Inherently Sfe design, then Engineering Controls, then Information for Use, then Administrative Controls and finally descending to PPE at the bottom. An arrow with the text "Effectiveness" on it runs parallel to the triangle and points downward from Inherently safe design to PPE.
This entry is part 4 of 5 in the series 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…

Read More
3 September, 2010

Guarding Emergency Stop Devices

by Doug Nix
in Control Functions, Emergency Stop /
8 Comments
Emergency Stop on machine console
This entry is part 3 of 16 in the series Emer­gency Stop

Can emer­gency stop devices that a prone to unin­ten­ded oper­a­tion be guarded? Find out!

Read More
17 July, 2010

Interlocked gate testing

by Doug Nix
in Asides, Guards and Guarding, Interlocks /
5 Comments

Did you know that inter­locked gates require stop­ping per­form­ance test­ing?

Machinery needs to be able to stop in the time it takes a per­son to open the guard and reach the haz­ard. If the dis­tance from the guard open­ing to the haz­ard is short enough that a per­son can reach the danger point before the haz­ard can be con­trolled, the guard is use­less. The res­ult­ing situ­ation may be worse

Read More
All original content on these pages is fingerprinted and certified by Digiprove