KIRK® believes that everyone has the right to be safe at work!  To ensure safety, the risk of hazardous energy and or equipment needs to be controlled.  Our trapped key interlock safety systems and safety components provide our customers with solutions to control these risks.

KIRK® manufactures more than 70,000 safety components each year for use in a wide range of industries, guaranteeing a sequential pattern of safe operations for isolating energy and safely accessing hazardous areas.  KIRK® safety products are designed and configured to each user’s requirements, providing protection from each application and peace of mind for our customers.

We educate customers, design firms, and OEMs on the benefits of our safety systems and work with industrial and safety associations to standardize the use of these systems. 

Our products include mechanical interlocks, electro-mechanical interlocks, solenoid key release units, time delay key release units, transfer panels, and smart technology. Proper application of our safety interlock systems guarantees that a sequential pattern is followed for each step of a prescribed sequence.




Key interlocking was developed during the 1890s to improve safety on the railroads for use in the application of railway track switching.  Ralph Levering, "R.L." Kirk was the first to pioneer the use of key interlocking on circuit breakers and switches, by reducing hazards caused by improper switching operations. R.L. Kirk filed for his first patent "Safety Interlock for Electrical and Mechanical Equipment and Systems" in 1931 and Kirk became an authority in electrical safety.

In 1932, KIRK® trapped key interlocks were manufactured in Greensburg, Pennsylvania, USA as part of the Railway & Industrial Engineering Company, which held the patent filed by R.L. Kirk.  Through the years, Railway & Industrial Engineering changed to ITE, then Gould, which turned into Gould Brown Boveri, and finally ABB.

In December of 1999, Kirk Key Interlock Company LLC separated from ABB and was completely independent, moving operations to Massillon, Ohio, USA. In 2011 Kirk Key Interlock Company LLC was purchased by the holdings company Halma plc, and in September 2014, 

moved operations and manufacturing to North Canton, OH, USA.

Through the years, electrical safety standards have evolved and the application of trapped key interlock systems has greatly expanded. Today, in addition to electrical power equipment, KIRK® trapped key interlocks are utilized on machine guarding, loading dock safety, and many other industrial applications to protect personnel and equipment. 

Click here to view our video, "History of Kirk Key Interlock".


Global Headquarters | 9048 Meridian Circle NW | North Canton, OH 44720 | USA  

                       (800)438-2442 | FAX (330)497-4400 |


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