Kirk Key Interlock Company LLC manufactures trapped key interlocks and safety interlocking systems for the protection of personnel and equipment. Our products include mechanical interlocks, electro-mechanical interlocks, valve interlocks, solenoid key release units, time delay key release units, and transfer panels. Proper application of our trapped key interlocks guarantees that a sequential pattern is followed for each step of a prescribed sequence. KIRK® key interlock systems are designed and configured to each user’s requirements and revolve around a key or keys that an operator must use at each step in the sequence. We manufacture four different styles of trapped key interlocks: SD Series, MD Series, HD Series, and Eagle Series interlocks, featuring valve interlocks for flow control applications.

Company details

9048 Meridian Circle, NW , North Canton , Ohio 44720 USA

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Business Type:
Manufacturer
Industry Type:
Health and Safety - Workplace Safety
Market Focus:
Globally (various continents)
Year Founded:
1932
Employees:
11-100

In 1932, KIRK® trapped key interlocks were manufactured in Greensburg, Pennsylvania, USA. Kirk started life as part of Railway & Industrial Engineering Company, which later became ITE, then Gould, which became Gould Brown Boveri, and finally ABB. In December of 1999, Kirk Key Interlock Company LLC became completely independent of ABB and moved to Massillon, Ohio, USA. In 2011 Kirk Key Interlock Company LLC was purchased by the holdings company Halma plc. As of September 2014, Kirk Key Interlock Company operates from a new headquarter in North Canton, OH, USA, as we continue to improve our manufacturing and efficiencies to ensure top quality products and customer service.

Developed during the 1890s to improve safety of railway track switching, key interlocking was pioneered by the American R. L. Kirk for use on circuit breakers and switches by reducing hazards caused by improper switching operations. As electrical safety standards evolved during the 20th century, the application of trapped key interlocks has greatly expanded. Today, in addition to electrical power equipment, KIRK® trapped key interlocks are utilized on machinery and many other industrial applications to protect personnel and equipment.  Since founding Kirk, our trapped key interlocks have been installed on electrical equipment and machinery in every continent in the world.

Kirk Key Interlock Company LLC is a subsidiary of Halma plc, a successful international company and market leader in specialist health, safety and environmental technologies. The financial, technical and human resources available to Kirk Key Interlock Company LLC enables us to develop innovative new products and focus on providing outstanding customer service. Halma is a public company listed on the London Stock Exchange.

  • A FRONT LINE SAFETY DEVICE for protecting both personnel and equipment.
  • Applied to two or more moveable parts, PREVENTING (OR ALLOWING) MOVEMENT.
  • Drives a PREDETERMINED SEQUENCE as specified by the customer to protect from hazardous energy.
  • Keys are transferred from one lock to the other using UNIQUELY CODED INTERLOCK KEYS.
  • TO PROTECT personnel from hazards by ensuring predetermined sequences of operations are followed
  • TO PREVENT financial setbacks due to expensive machinery and electrical equipment damaged by operator error
  • TO PROVIDE continuous service and manufacturing without interruptions due to mis-followed operation sequence

Fact:
In excess of 70% of reported accidents world-wide in the industrial marketplace are attributable to human error, accounting for 90% of the financial loss.
 
Fact:
Written operating procedures alone cannot prevent the inadvertent operation of equipment out of sequence.
 
Installing a trapped key interlock system ensures a predetermined sequence of events is followed. Whereas Lock Out – Tag Out (LOTO) provides a visual warning and some protection, a trapped key interlock system physically prevents a specific set of actions until the previous action(s) have been completed.

What Is A Trapped Key Interlock?
A trapped key interlock is a safety device applied to two or more moveable parts, preventing (or allowing) a movement or operation of one part only when another part is locked in a predetermined position. KIRK trapped key interlocks operate on the principle that the key can be removed only when the locking bolt is in a predetermined position. See diagram below.
 
The KIRK interlock is used to protect personnel and equipment, with the goal of eliminating errors that can occur when it is necessary to obey a sequence of predefined operations. The KIRK system prevents anyone from trying to circumvent the default and crucial to the safety of the procedure sequence. The KIRK interlocks can be mounted directly on the equipment, ie, the system is fully integrated and simple to operate.

  • TO PROTECT personnel from hazards by ensuring predetermined sequences of operations are followed
  • TO PREVENT financial setbacks due to expensive machinery and electrical equipment damaged by operator error
  • TO PROVIDE continuous service and manufacturing without interruptions due to mis-followed operation sequence

Fact:

In excess of 70% of reported accidents world-wide in the industrial marketplace are attributable to human error, accounting for 90% of the financial loss.

Fact:

Written operating procedures alone cannot prevent the inadvertent operation of equipment out of sequence.

Installing a trapped key interlock system ensures a predetermined sequence of events is followed. Whereas Lock Out – Tag Out (LOTO) provides a visual warning and some protection, a trapped key interlock system physically prevents a specific set of actions until the previous action(s) have been completed.