4L79 - Electromechanical Slam Action Cell Lock



To provide secure locking of swinging cell doors using third party access control systems or conventional key control where automatic deadlocking is a requirement.


The 4L79 is a surface mounted lock of robust construction based on the Chubb Locks Custodial Services standard cell lock footprint. The main bolt is automatically extended providing a throw of 32mm and deadlocked on closure of door.

  • Electrical Mode - Deadlocking is achieved when the door is closed and the bolt fully extended, no electric input is required to lock. Unlocking by 24 Volt DC from an external source to energise (lift) the locking solenoid and withdrawing the bolt via the handle. The bolt remains retracted when fully withdrawn and out of frame. Solenoid is designed to be momentarily energised to facilitate un-locking.
  • Mechanical Locking - Locking achieved using conventional (mechanical key) to engage a secondary deadlock when the door is in frame and main bolt is fully extended. Electric unlocking cannot be achieved while the mechanical locking mechanism is engaged.
  • Manual Override - In the event of power or communication failure an override key is used to lift (override) the electric locking unit. Both keys are supplied to a different combination and are clearly identified.


Standard Features

  • Solid Case Technology; Lock case machined from single piece carbon steel.
  • Steel main bolt, with carbide anti-cutting rollers, and 32mm throw.
  • Unique solenoid electric locking latch.
  • Independent 7-lever locking mechanism.
  • Factory restricted key section.
  • Lock provides status output of critical functions.
  • 5 bolt secure fixing.
  • Integral baffle arrangements to resist manipulation and interference via the keyhole.


  • Mechanical locking mechanism tested to a minimum of 100,000 operations.
  • Handle mechanism tested to a minimum of 300,000 bolt operation.
  • Solenoid locking unit tested to a minimum of 1,000,000 cycles.
  • Solenoids designed to operate at +/-10% of 24V DC regulated supply.
  • Nominal operating current 250mA.
  • Saw attack 12 hours
  • End load 8.0 kN
  • Side Load 25 kN

Additional Features

  • Anti-Ligature handle and escutcheon design.
  • Range of fixings including back plates, stud fixings, locking plate and keeps.
  • Interchangeable mechanical inner locking unit to enable re-coding.
  • Door cable available in 3M or 10M lengths (not supplied with lock)
  • This lock is not available under a master key system.


  • The lock is available in left or right hand variants for opening in or opening out doors and can be fitted to steel or wooden doors.

Dimensions & Weights

Case Height286mm
Case Length267mm
Case Thickness30mm
Bolt Throw32mm
Bolt Depth45mm
Bolt Thickness22mm
Weight (lock only)12kg



  • Lock case - carbon steel electro-plated and powder coated exterior.
  • Main bolt - carbon steel electro-plated.
  • Main bolt follower high tensile brass.
  • Keys - Hardened Steel
  • Levers and springs - Brass / phosphor Bronze.