Amputation Hazard Follow Up: Logan Clutch Door Interlock

Our recent post on the latest OSHA Emphasis program on Amputations brought us a comment from Michael Krizmanich at PMPA Technical Member Logan Clutch about avoiding violations (and potential amputations) through door interlocks. "Some screw machine customers use the Logan Clutch control for machine guarding. The CS2001 Microprocessor Control has two pairs of inputs for two Door Interlock Switches."

As staff providing member assistance to companies when OSHA visits and cites guarding, we have found that typically OSHA insists on door interlocks, despite the Kershaw Exemption which we have written about here.

So the Logan Cutch Door interlock is a potential solution to the OSHA identified guarding issue.

Door interlocks make the OSHA folks happy.

CS2001 Door Start Interrupt Switch Inputs: How They Work

The CS2001 Microprocessor Control has two pairs of inputs for two Door Interlock Switches. Each pair of is designed for one normally opened switch contact and one normally closed switch contact. The control senses both inputs together and has an override/defeat checking feature to monitor door input functionality.

CS2001 Safety Features & Safety Relay
The CS2001 Control has a stop circuit which integrates a Pilz Category 4, EN 954-1, model PNOZ X2.1 Safety Relay. The safety relay, provides dual-channel E-STOP with monitored manual reset. One channel of the Pilz Safety relay is connected to an output of the CS2001 microprocessor control. One channel of the Pilz Safety relay is connected in series to multiple, maintained contact, red mushroom head push buttons. A second separate contact of the red mushroom head buttons is wired in series into a CS2001 Microprocessor Control input. The reset input of the Pilz Safety relay is connected to an output of the CS2001 Microprocessor Control. All control power outputs to all external machine devices are wired thru the Pilz Safety Relay Safety Contacts.

Additional functionality included:

• Stock Load Position Selector Switch
• Thread Check Failure System
• Short Part & Broken Tool Detectors
• Stock Depletion Detector Inputs
• Machine Lock-up Detection

Here's a link with more information: http://loganclutch.com/cs2001-door-interlock

Editor's Note: CR4 would like to thank Milo for sharing this blog entry, which you can also read here.