Interlock switch delivers 5,000N lock force

Louise Smyth

IDEC has announced the release of its new HS1T interlock switch with solenoid. This delivers 5,000N of locking force, with many features included to maximise protection in machine and equipment guarding applications.

Interlock switches are incorporated into machinery and equipment to both monitor and lock gates, doors and similar access points. Many of these applications endure high vibration, thrown debris, physical abuse and even bypass attempts, so they must have a high locking force. Interlock switches are used to ensure guarded locations are secure before starting a machine and are also used to deny access to certain areas during operation, both critical for operator safety and protection. These devices must be strong, adaptable and secure.

It features a metal head integrating the locking and mounting functions, an improvement over older designs where the head could break away from the mounting body. Also, to maximise installation options, the remaining actuator portion can be independently rotated from the high-strength head using only one screw. With a slim form factor and many mounting options, the HS1T can be installed virtually anywhere, providing greater flexibility for designers.

Cam design also plays an important role. IDEC has included three independent rotary cams, instead of the single cam used by conventional devices. Two cams control the locking mechanism and one drives the door monitor contact. This arrangement provides redundancy, additional strength and ensures the monitoring function continues to work even if a locking cam is damaged.

The HS1T meets the requirements of ISO 14119:203 for Lock Monitoring and are marked is such. This means both the status of the position and the locking function of a protective door can be monitored through the lock monitoring contact. The net result is that fewer on-board contacts are needed to achieve redundant safety circuits and additional monitoring circuits, reducing the amount of wiring on the device. For additional integrity, the structure is designed so the lock monitoring contact can never indicate closed if the door is not positively closed, thereby preventing the associated machine from being turned on with risks exposed.