Safety applications where inertia plays a critical role in the risk assessment, like cutting machine or power press machines are challenging.  To prevent access to the hazard, they required the use of guard lock safety-door switches that can be locked and unlocked using safety signals. The D4BL series offers a high level of safety using a mechanism where the lock is only released when voltage is applied to the solenoid. The D4BL series offer an auxiliary release key to ensure easy maintenance, a holding force of 700N, led indicators for fast diagnostic, different operation keys options to support four different head mounting directions, and conforms to ISO 14119.

  • A mechanical lock is applied automatically when the Operation Key is inserted. A high level of safety is achieved using a mechanism where the lock is only released when voltage is applied to the solenoid.
  • Release protective cover locks using controller signals or push-button switches after the cutting tool stops moving due to inertia.
  • The switch contact is opened by a direct opening mechanism (NC contacts only) when the protective cover is opened. Direct opening mechanism that is EN-certified is indicated by a right-pointing arrow on the switch.


  • Conforms to EN (TÜV) standards corresponding to the CE marking
  • Certified by UL, CSA and CCC standards
  • Auxiliary release key ensures easy maintenance and unlocks the door in the case of a power failure.
  • Tough aluminum die-cast body incorporating a switch box with degree of protection satisfying IP67, UL, and CSA TYPE6P, 13
  • Equipped with a horizontal and vertical conduit opening
  • Models incorporating easy-to-see indicators for monitoring and those using an adjustable Operation Key for a swinging door are available
  • The mounting direction of the head can be changed to allow the Operation Key to be inserted from four directions