1885 Dimancea: A Revolver With Sprockets

Patented in 1885 by Romanian military officer Haralamb Dimancea, this revolver is actually a true hammerless design. Instead of simply shrouding a hammer inside the frame, Dimancea used a pair of rotating sprockets to cock and release a striker and act as hand and stop for the cylinder. The Gatling Arms Company of Birmingham England produced a run of 1,000 of the guns, which were used in Romanian military trials, and also tested by the French as a replacement for their 1873 revolver. Neither country ended up adopting the gun, though.

A .45 caliber 5-shot version was apparently made in small numbers, but the standard pattern (like this example) is a .38 caliber, 6-shot model. The barrel, crane, and cylinder pivot 90 degrees to the left to extract empty cases and reload. While Dimancea’s design was innovative, is really did not provide any benefit over a traditional revolver, and is considerably more complex to manufacture. It fires in double action only, with no mechanical way to manually cock the action for a “single action” shot.


        • Decker is really cool
          In both comparative and in absolute terms.

          I’ve spent a lot of time studying Decker’s patents, he had some good ideas, especially in ergonomics.

          Also check out his kids and grand kids musical careers; Desmond and Carol 😉

          • The Decker was, as far as I’ve been able to determine, one of only three pistols ever designed specifically to be fired from inside a pocket. The other two being the Moore/Colt “National” Derringer, and the “Little All Right” subcompact revolver.

            The Decker’s “plunger” trigger,like the triggers in the other two, was designed to avoid being caught on fabric. The “shield” on the right side of the Decker, that shrouds the cylinder, also was intended to prevent snagging. The “fake ejection port” was intended not to make the Decker look like a self-loading pistol, but was rather an elementary mechanical necessity. Since the Decker design required the removal of the cylinder for cleaning and maintenance, as well as any reloading other than one at a time through the loading gate on the left side of the frame, there had to be a “hole” in the shroud to allow the cylinder to be pushed out to the left once the base pin was removed.

            During WW2, the British SOE had an experimental 9mm revolver based on the French Dolne “Apache” pinfire pepperbox. I’ve often thought that a Decker type weapon, in .32 ACP, would have been a much more practical choice.



  1. Dimancea then went on to design a hammer fired bolt action that employed a clever combination of pulleys and flywheels. (/sarc)

  2. Even the barely adequate Type 26 revolver seems economically viable compared to this contraption! I could be wrong, but needless reinvention of the wheel is considered a lesson in futility.

  3. Peak FW?
    My wife summed this up: “So either he knew how to take that apart in advance. In which case- wow. Or he worked out how to take that apart. In which case…really wow!”

  4. Was this design rooted in the need to get around patents…?

    I sometimes wonder if there isn’t a better way of managing the whole concept of patenting ideas. You look at things like the Colt through-bore cylinder patents that held back competition in cartridge revolvers for so long, and you have to wonder if there is a smarter way to manage the issue.

  5. This is one of those cases when otherwise meticulous individual took on task of designing a gun without previous exposure/ background. It takes person who has background in the trade and is familiar with state of art. But, there are exceptions.

  6. Looks like this revolver could have a slightly different trigger pull and sear release for every chamber on the cylinder.

      • Revolvers are still valid arms, as they are simpler and sturdier than self-loaders. (Consider the typical operating pressures of autopistol rounds compared to what revolvers can tolerate; 9 x 19mm vs. .357 Magnum, just for starters.)

        For typical casual handgunners, the DA revolver is safer and more “user-friendly” than any autoloader. As NYPD found out when they changed from the S&W Model 10 .38 to the Glock 17 9 x 19mm in the early 1990s; ADs went through the roof, often literally. The result was the “New York trigger” for the Glock, that increased trigger pull to about half again that of the DA pull of the Model 10. the result? Fewer ADs at end of watch and on the range, but also more misses and “collateral damage” to innocent bystanders “on the street”. This is called “progress”.

        The major drawback to revolvers today can be summed up in three words; “Colt” and “Smith & Wesson”.

        The two firms have dominated the revolver market for over a century and a half. And today, Colt refuses to make revolvers except through their custom shop, and S&W refuses to make revolvers and sell them for reasonable prices.

        Colt’s latest revolver other than their overpriced Peacemaker is the “New King Cobra”. It is a three-inch barrelled Police Positive Special in .357, which they are trying to sell for twice the price of the original King Cobra, which was a much better piece of work. But like their Peacemaker (or any of their 1911 variants), they expect you to pay them carriage-trade prices because it says “Colt” on the side.

        Similarly, S&W are charging premium prices for everything, mostly by tacking the word “Classic” onto the end of every product designation. There is no logical reason for a four-inch, blued, fixed-sight Model 10 Military And Police .38 Special revolver to cost over $900 MSRP. There just isn’t.

        Especially because you can buy the exact same revolver, with the four-inch heavy barrel, for half that from Taurus, in stainless steel to boot;


        For that matter, you can find a duplicate of almost every revolver S&W makes in the Taurus line, or that of their Rossi subsidiary, and none of them costs more than about half what S&W is asking.

        Similarly, you can buy a Peacemaker from any of a dozen other makers for about a fourth of what Colt demands. Any of which will probably do their job as well as the Colt “original”. Or in the case of a Ruger, a lot better due to more modern engineering inside.

        The revolver, in single or double-action, is still the simplest and most reliable repeating handgun that nine out of ten shooters can cope with. And it will do just about anything that needs doing that can reasonably be done with a pistol.

        There’s nothing wrong with the revolver, either single or double action, that Colt and S&W going out of business wouldn’t fix.



        • Owning and using of revolvers may be low in general persenage but, the practial handgun mentality included in them are still the peak aim for pistol designers; Making a sample as simple and safe as in use of a revolver.

        • “(…)inch(…)”
          There is also one advantage of revolvers, as opposed to recoil-operated automatic pistol, is that revolver’s function is independent from barrel mass (barrel length), which allows manufacturers to offer revolvers with various barrel length with neglible if any cost of development. In fact some manufacturers even offered system allowing quick swap between shorter/longer barrels, for example Merwin Hulbert:
          This allow user to decide between better ability of fast deploying (short barrel) or longer sight radius (long barrel).
          Recoil-operated automatic pistol, are extremely rare through history, but do exist, see for example P38 IV:
          – that is shortened version of P38.

      • “Revolver is a history; it is a fossil. It reached its peak in WWI. Look where development has moved.”
        I would say that peak of development was even earlier – end of 19th century/dawn of 20th century. Note that swing-out cylinder become part of production revolver yet in 19th century: https://guns.fandom.com/wiki/Mod%C3%A8le_1892_revolver
        Later, revolver evolution went rather into harnessing more powerful cartridge, with other changes being rather cosmetic.
        Note OTs-38 noise-less revolver, designed by Stechkin, which was not limited by any tradition or need to suit customer tastes, which sports some uncommon features:

  7. H. Dimancea was awarded British Patent #9973 on 22nd August 1885. The patent has a drawing and description of the mechanism, the wheel is described a “ratchet-wheel”.

    • That sounds to me linguistically more correct. Sprocket usually refers to gear of chain power transmission (such as on motorcycles).

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