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.
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.
Last edited: