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Hydropump charged UBL Hydropneumatic Speargun

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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popgun pete

Well-Known Member
Jul 30, 2008
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http://ubl.dp.ua/nashi-razrabotki/208-samoe-moschnoe-podvodnoe-ruzhe

I was thinking about how this new gun was loaded before charging it up to shooting pressure with the hydropump. On an Aquatech hydropneumatic speargun the spear can be pushed down the flooded barrel tube without much effort as with the trigger pilot or control valve left open the water pushed down the barrel by the spear tail exits out of the hydraulic locking chamber if the latter is not sealed. In fact neither the spear being pushed in nor the hydropump being worked will have any effect as water going in will be matched by water going out. With the locking chamber sealed the gun can be charged with the hydropump and the gun only shoots when the locking chamber is opened by the trigger cracking open the control valve which then allows the releasing or firing valve to open and release pent up water under pressure which ejects the spear from the gun.

Now this new UBL speargun uses a mechanical release to open the releasing or firing valve which is controlled by the sliding inner barrel tube, so how does water get out when the spear is first pushed in? The releasing valve will be closed so water being pushed in by the spear has nowhere to go. The answer is a small opening controlled by the gun's line release that opens the area up immediately behind where the spear tail stops after insertion into the barrel. When left open water passes out to the environment through this hole, hence the spear can be pushed down the barrel with little effort after which the line release is closed and that closes the opening. During the shot the elevated hydraulic pressure in the barrel pushes water out of this hole as well as going down the barrel, but the large difference in their respective diameters means that there is no real loss to spear propulsion. Actually this small hole has a counterpart in the Aquatech guns and that is the transfer port hole in the Aquatech releasing valve piston. It serves a different purpose there, but also allows another pathway for water to exit the gun during the shot, however a similar size differential means that little water can escape through it rather than head off down the barrel which offers the least path of resistance. Another benefit for the UBL speargun is that the water leaving via the small hole behind the barrel powers the line release lever opening and thus ensures its synchronization with the shot, something that has proved troublesome with some recent models of pneumatic spearguns.
 
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The "power operated" line release that I am referring to is shown here on the UBL website videos.
release 1.jpg
release 2.jpg

This next diagram shows the transfer port channel in the Aquatech gun.
transfer port.jpg
 
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Although this schematic is for a pneumatic it still shows the trigger mechanism for a "Zelinka" type speargun where the sliding inner barrel controls the releasing valve. This is the system used by the "UBL" hydropneumatic speargun.
shema zelinki big E.jpg

Rather than a piston there will be a seal on a spear tail that serves the same function as a piston, but the inner barrel will be flooded. The compressed air reservoir can be separated from the water by a sliding annular piston moving on the inner barrel tube and the inner wall of the concentric tank..
 
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No no my friend. Water extractet exactly from burrel. There is no holses in muzzle
 
No no my friend. Water extractet exactly from burrel. There is no holses in muzzle
Well a diagram from you may help as I am not saying there is a hole in the muzzle, your photos above show that the small bypass hole must be rearwards of the barrel, but forwards of the releasing valve. We can see that it is in front of the hydropump from the position of the line release lever. Be aware that on-line translators can switch around the order of words as the grammatical rules for that language are applied. I noted this when posting on Apox.ru by double checking on the translation of what I wrote in Russian which gave different results each time!
 
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A diagram for a Zelinka hydropneumatic type gun with a hydropump fitted; note that this is a conceptual drawing only and not a "blueprint" for such a gun. As shown here the port to the line release would move with the inner barrel, which it obviously cannot do, but it must connect in front of the releasing valve or gun pressure prior to shooting would blow it open prematurely. I don't have time to draw a new diagram, so have just adjusted an existing one in order to indicate the relative arrangement of components rather than their actual shapes and dispositions. This gun is only charged with the hydropump, not by muzzle loading strokes with the spear in the inner barrel. During muzzle loading the port to the line release is left open so that water pushed down the barrel by the spear tail is ejected out of the gun.
zelinka hydropneumatic R.jpg
 
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The next thing to work out is how the "UBL" hydropeumatic gun is filled with compressed air prior to being used, or at the start of the hunting season. In the "Zelinka" pneumatic speargun, shown in schematic form above using a diagram borrowed from "fishgun-master.ho" (http://www.fishgun-master.ho.com.ua/princip raboti zelinki.htm), the gun is pressurized using the inner barrel tube as an air pump. The air pump rod and piston, which may be the spear and inner barrel sliding piston, are worked back and forth with the muzzle converted to pumping mode by unscrewing it sufficiently that air can be taken in using the muzzle relief ports as the rear piston seal clears the inner barrel mouth on the pump upstroke. The Inalex "Alpha C1" pneumatic speargun is also pressurized with air in this way and if you refer to that thread you can see a diagram showing how "pump mode" is achieved.
https://forums.deeperblue.com/threads/inalex-alpha-c1-pneumatic-speargun.88246/
Inalex fig 5 R.jpg


The usual method of pressurizing releasing valve guns, without using the inner barrel as an air pump, is to mount an inlet valve at the front end of the air tank and attaching the handpump, or air supply (e.g. scuba tank), using a collar attachment that temporarily surrounds the air tank with an annular clamp. However there does not appear to be an inlet valve at the front end of the gun, or more accurately the front end of the air tank, so I hope the inventor Dimi can tell us or it will have to remain a mystery.

One exception to the releasing valve guns not using a hand pump attachment at the rear end is/was the GSD pneumatic spearguns. While notionally the releasing valve blocks access at the rear of the gun for the attachment of a handpump, the GSD speargun had a rear bulkhead extension that allowed air to enter the gun from the rear as can be seen in this next diagram. An ingenious design, but it made the rear end of the gun heavy until the later "Katiuscia" model reduced the volume of metal in the rear bulkhead area by using four outward projecting "dogs" to engage four slots to secure the rear end of the air tank on the gun. Note how long the inlet valve stem is in this GSD "Dynamic" speargun.
GSD Dynamic speargun layout.gif
 
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Dima filled the HP Tuna gun from a scuba tank. Can't recall if it was a muzzle adapter or if it connected to the middle part of the gun.
 
Any air inlet valve has to be forwards of the annular piston's travel distance inside the gun body so that the piston does not run into the valve. The inlet valve could be an annular rubber ring type valve as used in the "RPS-3" and the "Aquatech". The reason that I started this thread is that I am hoping to entice Dimi (or is it Dima?) into putting all this sort of info here himself. Just looking at the bare "UBL" gun body without the wooden jacket there are a number of steps in diameter where a collar could be secured to clamp an air transfer hose onto the gun in order to pressurize it. Just exactly where the tank ends is another consideration.
bare body UBL Hydropneumatic.jpg
 
It's Dima, short for Dmytro, which I guess is an alternative spelling of Dimitry/Dmitry:)

He's been busy lately and also, he might keep things a bit close. I speculate he just wants to make sure the gun is absolutely perfect before he says it is finalized.
 
I am sure that he drew up a schematic while planning the parts for the gun and that is what I think many would be interested in seeing. Schematics do not have to be exact and detail changes to designs are often incorporated later. For example the Aquatech "Black Sea" speargun schematics cover the main features, but they don't accurately depict all the details in their construction. Changes were made over the years that don't feature in the diagrams as they were in a sense second order issues.
 
Note the speargun mentioned here https://forums.deeperblue.com/threads/how-things-change-or-maybe-they-have-not.108022/ which is a pneumatic, but uses water to push a piston back against high pressure air on the other side of the piston. Same loading principle using a hydraulic pump, however the spear is fired from that barrel (at 23 mm ID!) as opposed to firing using the released water in a smaller barrel such as 9 mm or 10 mm ID. Due to the stainless steel tubing used for the inner barrel the UBL speargun uses 10.4 mm ID, but that is just from memory as I have not recently checked it.

"Iyadiver" was into shooting Tuna with a small "Metaltech" stuffed with 5 bands and using an underwater parachute to slow the Tuna down as it fled dragging the breakaway rig behind it, so such a powerful speargun was of interest as it would be relatively easy to load. Until the water had to be tipped out of the inner barrel and replaced with the spear!
 
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