SPEAR-FISHING GUN INCLUDING FREE PISTON ON THE HARPOON

摘要

An underwater spear equipped with a cylindrical cavity (7) and a free piston (44) which, at the moment of launching the spear, divides the cavity to a smaller front part where the piston hermetically closes a certain volume of compressed air through a nozzle (42) in the rear end (41) of the spear, producing thereby a reactive force during and in the direction of the spear movement. The speargun has a mechanism for charging the spear with water through the nozzle while the spear is fixed in the gun consists of manual piston pump (9), pressure cylinder (1), hollow pressure piston (2) and hollow spear pusher (6) with non-return valve. In a second embodiment there is no spear pusher. The non-return valve is located at the pressure-cylinder water intake (27) and the pressure piston is replaced by the very rear end of the spear.