How Does It Work: Toggle Actions

Toggle actions are a relatively exotic locking system that are relatively common and well-known because the system was used in a pair of particularly successful early guns: the Luger and Maxim/Vickers. There have also been toggle-action shotguns, military rifles, sporting rifles, and submachine guns, but the system went out of favor by the 1930s (except in the mind of one Adolf Furrer).

Most toggle-action designs use the toggle as a locked breech system, unlocked by a secondary operating system (usually short recoil). However, toggle system can also be the basis for delayed blowback actions, as in the Pedersen rifle.

25 Comments

  1. You should’ve also included the Winchesters 1860 1866 and 1873 they also use the toggle link mechanism to lock the breach

  2. A lot of aircraft use over-center locks on retractable landing gear. Basically, the retracting strut hinges in the middle to shorten, pulling wheels up.
    When fully-extended, the retracting strut over-extends like a gun’s toggle lock, preventing it from folding while loaded (airplane weight). It is a simple weight-on-wheels safety mechanism.

  3. Good instructional video, Ian. But other than the Luger and the Maxim, I am unfamiliar with the other actions you illustrated but DID NOT NAME. What the heck are they? 🙁

    • Swiss Furrer SMG, unknown long arm, Schwarzlose 1901 prototype, and I did not recognize the sideways-toggle sporting rifle. Wish I recognized them all.

  4. Toggle locks are a pretty common mechanism in industry for clamps and other related purposes. Anyone who had experience doing mechanical design or working in a machine shop or factory should be very familiar with the concept.

    That of course doesn’t take away from the design cleverness of finding a way to apply this principle to a firearm, but it does show that it isn’t an obscure phenomenon.

  5. Auto loading via toggle action is a kind of delayed blowback type but there is a confusement about the terms of using “Delayed” and “Retarded” actions which seeming as neglected nowadays


    According to Chinn who used these terms at definite classifications in his books “Machinegun”, “Delayed blowback” refers to the actions with recoiling barrel with angled locking surfaces which unlocking occurs not at once but through slow order, and “Retarded blowback” refers to the actions with fixed barrel via slow opening breechbolt
 This means the commonly used term “Delayed” nowadays should be as “Retarded” 
 According to Chinn’s classification


    It should be also noted that, in hand and shoulder smallarms, there is no “Delayed blowback” firearm at all as suiting in the Chinn’s classification
 IMHO.

      • Thanks for the link Daweo
As understood from the schematics, this is a longer than short recoil toggle action gun with a movable third link swinging downwards to unlock the toggle engagement instead of the second which takes place at the middle and under the line connecting first and third


  6. Toggle lock is the oldest fixing actions used through at every kind of devices and at firearms, its use goes even earlier than Volcanic and Winchester guns and it is also said, “Borchardt” who had worked at “Winchester” in that era, derived his pistol from 1866 Model rifle as a recoil operated gun and possibly not thinking the “Delaying effect” of ıts nature in his mind


    Toggle lock used in “Pedersen rifle” is rather different in which, it uses staged two force spplication point as changing in sequence through getting primary recoil at along with the delay effect of linkage


  7. Please excuse my asking but is there a reason why you dont wear cotton gloves when you handle firearms especially antique ones.

    • Ian answered in a Q&A that it depends on the filming locations. Some places require gloves (cotton for some or latex for others) and others forbid them to avoid the risk of dropping the objects.

  8. Good video buw you overlooked an important modern use of to toggle actions: Many straight pull .22lr rifles, especially many biathlon rifles, use manually operated toggle actions. While other .22lr straight pull actions became more successful since the 1980s they still remain relevant.

  9. Do not confuse positive locking systems (like Luger, Maxim, Furrer) and delayed unlocking systems (like Schwarzlose or Pedersen)
    These are completely different principles both in the unlocking method and in the automation engine.

  10. Probably the earliest toggle-locking system used in firearms was the Merrill breech system. Ian covered a couple of its applications in previous videos;

    Merrill-Jenks Navy carbine;

    https://www.youtube.com/watch?v=MdglHGMAAGA

    Merrill conversion 1841 Mississippi rifle;

    https://www.youtube.com/watch?v=uQmiYR96kq8

    One rather obscure example was the C.C. Barnes “machine gun” patent of 1856. It was actually a single-shot, quick-firing light cannon proposal similar to the 1860 Williams gun used by the Confederates in the CXivil war. While its breech was operated by a side crank like the Williams gun, instead of the rotating “cam” action of the Williams, the crank operated a toggle to lock the breech.

    To judge by the patent drawing (see p. 97 of Small Arms of the World, 9th ed., 1969), unlike the Williams, the crank did not make a complete revolution; it was pulled up and back to open the breech and pushed down and forward to close and secure it. So in terms of how it was “worked”, it would be more like the Nordenfelt gun with its “push-pull” lever on the side.

    cheers

    eon

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