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Commander Yves Le Prieur band gun 1938

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popgun pete

Well-Known Member
Jul 30, 2008
Here is the patent diagram for an impressive band gun devised by Commander Yves Le Prieur who was a diving pioneer, prolific inventor and Navy man and should be as well-known as Captain Jacques Cousteau. Among his many achievements are the first practical scuba, the first underwater “Nautilus” speargun powered by blank cartridges and later by bottled compressed air and the formation of the world’s first diving club using his “Scaphandre” breathing apparatus. Alexandre Kramarenko patented the world's first underwater spring powered speargun in 1937, but hot on its heels was this much more practical and floating band gun which was patented in terms of its priority date in December 1938.

Unlike many subsequent speargun patents in the thirties and forties this gun actually worked. Note the provision of front and rear targeting sights on the speargun and the eight band power system which even with the relatively weak rubber of the time would have delivered a powerful shot. A floating reel is used with the gun and there is an optional shoulder stock which is similar to the one on the “Nautilus” cartridge/compressed air speargun. A leaf spring item 28 on the patent diagram stops the spear falling out of the gun's side-slotted barrel tube by pressing upwards against the tail end of the spear. The spear has a replaceable tip and a pivoting flopper located behind the spear tip to retain the speared fish, so everything required to successfully spear fish underwater is in place 80 years ago!

Le Prieur's surface gun R.jpg

Le Prieur's surface gun without float R.jpg

Yves Le Prieur and Nautilus Speargun.jpg

The "Nautilus" gun in its cartridge powered form being demonstrated by Commander Le Prieur.
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The Le Prieur band gun is seen here with a spring gun handle fitted to the rear end in order to provide a production gun trigger mechanism instead of the “declic” original, but this is essentially the same gun. Photos of the Le Prieur gun show the muzzle band anchoring system, which clamps the rubber band loops in place, and the sliding spear pusher unit with curved hooks protruding from the barrel side slots that the rubber band loops are pulled back to during cocking of the gun. My guess is that the rubber band loops are sections cut from scrap tire inner tubes, probably truck tires, as these eliminate the problem of anchoring cut rubber strands that will be highly stretched in things such as metal hooks and rings. Note that band rubber, screw fastener ferrules and wishbones are yet to be invented and only appear in 1943 with the Cavalero "Champion" speargun which itself is only produced in any volume after the war.






Unidentified until I saw it in a French historic speargun collection this gun will be extremely valuable, but if it had its original rear end then it would be virtually priceless. That said, it could be by the time the gun was actually produced that it may always have had this handle. World War II put a general damper on diving and spearfishing activities, but somewhat ironically many ideas were developed in France by talented engineers and divers that all came together once the war was over. The proliferation of French spearguns used around the world in the fifties and sixties was due to the leadership of France in this area.
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How the Le Prieur speargun would have looked powered up with four loop bands on either side of the gun. An impressive bit of artillery at the dawn of spearfishing with rubber powered underwater weapons.
LE PRIEUR BAND GUN with bands 4 2.jpg

Le Prieur's band gun with shoulder stock.jpg

NB. not at the same scale to fit above image with cocking stock on the page.
Le Prieur gun cocked to shoot plan view.jpg
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It would be an interesting exercise to recreate Le Prieur's band gun and bring back to life one of the first band guns ever. From the patent record it may actually be the first, full stop!

Note that in the embodiment photographed here that the shock absorber spring has been replaced by a rubber tube version located closer to the muzzle, which means that the spear pusher unit "coasts" for the last part of the barrel travel, but under considerable momentum. In my considered opinion the Japanese rollergun stems from this gun, the "coasting" drive travel section being eliminated via the use of muzzle rollers and those gun still effectively use "loop bands" just as this gun did. Commander Le Prieur spent some time in Japan and this I believe closes the loop on the origins of those guns and the beginnings of all band powered spearguns that actually work! Q.E.D.
Japanese rollergun detail CXR.jpg

japanese rollergun.jpg

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The Le Prieur speargun armed and ready to shoot. Although flat strap rubber that is 16 pieces of rubber, top and bottom!
Le Prieur's gun shoulder stock bands cocked profile.jpg
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The "declic" trigger mechanism used in the 1938 gun, basically a two-piece trigger with the sear lever also being a leaf spring as it bows downwards when the long trigger is pulled. Long triggers enable more fingers to wrap the trigger, most spring guns had big trigger finger guards to allow two fingers to pull on the trigger as often there is a tendency for this trigger mechanism type to initially move the spear very slightly rearwards against the pull being applied to the spear from the propulsion spring or bands.
trigger declic.jpg
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