US2784712A

US2784712A - Subaqueous harpoon gun

Info

Publication number: US2784712A
Application number: US364895A
Authority: US
Inventors: Joseph F Cassidy
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-06-29
Filing date: 1953-06-29
Publication date: 1957-03-12
Anticipated expiration: 1974-03-12

Description

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MGT* www QCNS N 9 1..L oONS. 9Min 1 In c r a M United States Patent O SUBAQUEOUS HARPOON GUN Joseph F. Cassidy, Oakland, Calif.

Application June 29, 1953, Serial No. 364,895

1 Claim. (Cl. 124-11) This invention relates to harpon guns for use under water by deep water game hunters.

Certain known guns of this character have utilized successfully a cartridge of compressed gas for a propellant for firing a plurality of rounds with each cartridge after which the cartridge is replaced. The `buoyancy and bulk of cartridges prohibits the hunter from carrying more than one or two cartridges and the cost tof their replacement in terms of time, effort, and nance is a factor desirably to be reduced.

in order to overcome such disadvantages and to gain others the present invention provides for the utilization in such a gun of the environmental water, the hunters energy, and a permanent volume of gas in such a manner that the need for cartridges is entirely eliminated and a practically unlimited number of harpoon launchings may be obtained by utilizing energy supplied alone by the physical exertions of the hunter. The water, in which the hunter and his gun are normally submerged while hunting progresses, is also employed `as part of the guns actuating and control mechanisms and it is normally released from the gun when the gun is not in use. The gun is accordingly constructed of a minimum weight of its parts, and it is constructed in a rigid and relatively invulnerable manner. Notwithstanding that the gun utilizes the liquid environment, it may, when once loaded with energy, be fired when outside the water so long as .the water and adequate energy to its use remains in the hydraulic systemfof `the gun.

Other objects and advantages of my invention will become evident from the following specification `wherein `reference is made `to the accompanying drawings, in

`harpo'on shaft to the gun;A and Fig. 4 illustrates-analternative form of tethering mechi anism.`

The gun comprises a straightpreferably internally circularly cylindrical. barrel .forreceiving the correspond- Hingly. straight circularly cylindrical steel piston plunger shaft "12, Athe `butt .or breechend 14 of .which `fdetines, in loaded position, the piston area exposed to projective hydraulic force in a chamber 16 formed by the gun proper. Aspear blade 18 tits over the end of the shaft 12 and is held captive by a tlexible cord or stranded wire 2i) extensible from a free running reel 22 suitably mounted on the gun.

In general .the gun comprises `a gas pressure energy accumulator 24, a manually driven hydraulic compressor pump 26, a iiuid actuated main valve 28 having the form of a spool valve, a manually actuated trigger or pilot valve 30, and auxiliary apparatus including `a safety trigger mechanism 32.

The accumulator comprises essentially a rigid bottle 34 ICC of steel or the like and a sealed envelope 36 of rubber or the like filled with air or other gas to a relatively high initial pressure such as two thousand pounds per square inch with the entire volume of the bottle 34 occupied by the inated envelope 36. The pump 26 has an intake pipe 38 exposed to the water in which the gun is submerged with lthe hunter and a discharge 40 connected by a tube 42 with an inlet tting 44 of the bottle 34. A suitable handle, not shown, is provided on pump 26 and the pump is constructed to develop up t0 two thousand tive hundred pounds per square inch pressure, more or less, at the discharge when the user operates the handle of the pump, which unit pressure is therefore applied inside the bottle 34 against the external surface of envelope 36 to compress the gas in the envelope and to store water under high pressure in the bottle space thus made available.

The accumulator inlet fitting 44 is provided with known protective means not shown to prevent extrusion `of the envelope through the fitting when the water is fully discharged, and fitting 44 further constitutes with anextension tube 46 a discharge passage 48 to ithe main valve .218 which discharge passage is closed by the main valve 28 at all times other than during spear launching; and as shown in Fig. 2 it is closed and held closed by the hydraulic liquid pressure applied to its piston area 50 from the accumulator 24 through the passage of tube 42 via two trigger

valve lconnecting tubes

52 and 54 connecting the chamber 56 through a passage 58 formed by valve 30 to the liquid in accumulator 24.

All elements remain static after the gas filled envelope 36 has been adequately compressed and until the trigger valve 3@ is opera-ted to the firing position. The static or loaded position is illustrated by Fig. 2, except that plunger '78 and its spring are in the Fig. 1 position.

Operation of the trigger valve 30 to the tiring position of Fig. l releases liquid from piston area 50 in main valve closing expansion chamber 56 through the connecting tube 52, a passage 60 in pilot valve 30, and to discharge port 62 formed in valve 3i) into the watery environment, or to atmosphere if the gun is tired in `atmosphere; and also admits water from accumulator 24 to a piston chamber 64 against the piston area 66 of the moving spool 68 of valve 28 via

tubes

42, 54, the passage 58 formed by valve 30, and a tube 70 joining valve passage 58 to the main valve opening chamber 64. This causes `main valve 28 to take the firing position shown in Fig. 1 in which position it provides a passage 72 around its spindle 74 from the accumulator discharge v48 into the chamber 16 wherethrough water from accumulator 24 is forced against theibutt 14 .of shaft 12 and forces the shaft entirely out of the gun barrel l() with high velocity.

Provision is made `to cut oit the release of water from accumulator 34 when the shaft has acquired ample speed in lthe barrel. For this purpose the trigger valve 3l) is provided with a trigger valve resetting device comprising a delay piston '78 normally extended by a spring 80 to close a port 82. In Fig. l `thedelay piston 78 is shown in `a position closing port 32, a position to which it is returned by spring dit from the Fig. 2 position after trigger valve 30 has been reset by delay piston 78. Initial operation of piston 73 is eiected by water from accumulator Z4 passing the spindle passage of valve 28 through a main valve portion 34, a tube 86, an adjustable needle valve S8 and entering the delay piston chamber 90. The needle valve 88 is set to restrict admission of water `therethrough to chamber 90 at such a rate that the trigger valve 34.9 remains in the tiring position of Fig. 1 until the breech end 14 of shaft 12 is almost out of the barrel. At such time the high tlow I'inlet port 82 to chamber 9i) is opened incident to movement of piston 78 and trigger valve 3i? is instantly moved to provide a discharge passage 96 from the main valve chamber 64 via .tube 70 to discharge port 98 and reestablishes a path for liquid from accumulator 24 to main valve closing-chamber 56 via

tubes

42 and 54, passage 58, and tube 52, thus causing return of the spool 68 to the Fig` 2- position, in which position a valve port 100 is uncovered tto allow entry of water into the passage around spindle 78 which also now communicates with chamber 16 through a tube 102 the purpose :of which communication is to prevent the occurrence of a vacuous condition in the barrel upon cutting oli flow of liquid thereto Jfrom accumulator 24. Port 100 and tube 102 as so set, allow the shaft 12 to enter the barrel forcing liquid before it out port 100.

The trigger valve actuating mechanism may include a ngerpiece 104 for manual actuation counterclockwise as `shown about a pivot pin 106 xed on the gun frame to drive through lever 108 pivoted at 110 and through links 112 `and 114, a plunger 116 pivotally pinned to link 114 at 117 and arranged for sliding on a slide surface pro vided by frame part 118. The other end of plunger 116 carries a cam roller 120 normally engaging a mating recess 122 in a plunger rod 124 fixed to the movable part 126 of trigger valve 30.

Fixed to the gun body or frame is a deflecting cam 123 in the path of movement of cam roller 120 at the firing position of valve 30. In operation: as the Fig. l position of valve 30 is reached by the trigger link 116 the roller 120 is deflected to the position shown against the tension of a spring 130. If the fingerpiece is held in the position shown the rod 124 simply slides over the roller 120 when delay piston 78 moves valve 30 toward the position of Fig. 2, thus avoiding injury to the gunners finger. The spring 130, or another spring not shown, is arranged to return the linkage to the Fig, 2 position when fingerpiece 104 is released.

Immediately after valve 28 takes the Fig. 2 position the delay piston 78 is driven by spring 80 to the Fig. l position. Since the port at 84 of valve 28 is now closed, :spring 80 works against trapped liquid in tube 86. The motion is permitted by bleed passage 79 which corn- -municates with port 81 in the spring cage, the bleed being the path of valve 30 through port 81.

In Fig. 3 the tether mechanism is shown to comprise a ring a directly tied through a `cord 20 to the gun 10. A pair of radially spring biased pawls 20h are pivoted in the -shaft 12 near butt 14 so that the pawls lie within the shaft 12 when in the barrel. The shaft is inserted through the ring 20a before passing into loaded position in the barrel.

Another tethering `arrangement is shown in Fig. 4 to comprise a reel chamber 140 formed in the gun frame and connected with the same chamber as the gain barrel. A free running reel 142 is mounted in the chamber with the tether cord 144 running tangent therefrom along the axis of the barrel 146 and anchored to the butt 14 of the harpoon shaft. Thus the cord trails along the axis of the shaft 12 as it is ejected, and improves the aiming quality of the gun.

ln Fig. 4 the barrel part 16 connected to valve 28 is joined to barrel 146 through the U-shaped portion 148 forming chamber and also forming a reverse flow path for the hydraulic liquid. By utilizing this arrange ment the valve and accumulator parts may be positioned adjacent to the barrel 10 between the ends of the barrel in order to achieve better proportioning and balance of the gun. lt is preferable in this way to dispose the accumulator 24 near the center of buoyancy of the gun so that changes in its specific gravity are more evenly distributed.

Having thus described my invention, including its construction and mode of operation, I claim:

A gun of subaqueous use, comprising: a gun barrel, a rigid compression chamber xedly secured to said barrel and having therein an elastic `air sac, a uid pump, means connecting said pump to said chamber for the delivery of fluid thereto, said chamber and pump constituting a source of huid under pressure, a spool valve having a spool therein and said valve being connected to and between said source and said gun barrel for the control of iiuid flow from said source to said gun barrel thru movement of said spool between a rest position and a re position, such fluid iiow to said gun acting therein as a propellant, a multi-ported slide connected to said source and to said spool valve for controlling the liow of fluid from said source to the ends of said spool for actuation thereof between such positions, said slide having a rst station and a second station, a trigger link for moving said slide from its rst to its Second station, said slide in its first station eiecting communication between said source and an end of said spool so that iluid under pressure will move said spool to and hold said spool in its rest position, said slide in its second station eifecting communication between said source and an end of said spool so that fluid under pressure will move said spool to and hold it in its hre position, a piston adjacent and arranged to actuate said slide to move it from its second to its rst station, a cylinder for said piston having formed therein two ports which are in `communication with said source thru said valve when fluid ows thru said valve to said barrel, one of said two ports opening into the head of said cylinder and the other opening into the side of said cylinder adjacent the head, whereby, when uid flows thru said spool valve, fluid will be delivered to said piston first thru the head thereof and then later thru the head and the side thereof so that said piston will move said slide from its second to its first station to allow fluid from -said source to ow thru said slide to one end of said spool to `move it to its rest position.

References Cited in the le of this patent UNITED STATES PATENTS 387,517 Jackson Aug. 7, 1888 1,180,000 Bloom Apr. 18, 1916 1,183,644 Hill May 16, 1916 2,421,810 Simpson June 10, 1947 2,546,961 Amero Apr. 3, 1951 2,574,408 Moe Nov. 6, 1951 2,581,758 Galliano et al. Ian. 8, 1952 2,688,321 Martin Sept. 7, 1954