US 3735747 A
Compressed-gas gun for projecting a spear under water, consisting of a compressed-air tank and a gun body formed of two tubes assembled end to end, one located at the front which constitutes the barrel and the other which contains an elastic sleeve serving as impervious joint between a compressed-gas reserve chamber and the barrel. The elastic sleeve and body define a further chamber which is cooperative with a trigger to selectively release the spear. Pressure on the spear by the elastic sleeve holds the spear tight before firing, but deformation of the sleeve away from the spear during firing permits the spear to be released.
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Description (OCR text may contain errors)
. 22 Filed:
[21 Appl.No.: 57,184
United States Patent [191 Barjavel UNDERWATER COMPRESSED-GAS GUN  Inventor: Jenn- Barjavel, 70 Avenue Gernuschi, Nice, France July 22, 1970  Foreign Application Priority Data [451 May 29, 1973 1,122,873 1/1962 Germany ..l24/1l Primary ExaminerRichard C. Pinkham Assistant Examiner-R. T. Stouffer Att0rneyWard, McElhannon, Brooks & Fitzpatrick [5 7] ABSTRACT Compressed-gas gun for projecting a spear under water, consisting of a compressed-air tank and a gun body formed of two tubes assembled end to end, one located at the front which constitutes the barrel and the other which contains an elastic sleeve serving as impervious joint between a compressed-gas reserve chamber and the barrel. The elastic sleeve and body define a further chamber which is cooperative with a trigger to selectively release the spear. Pressure on the spear by the elastic sleeve holds the spear tight before firing, but deformation of the sleeve away from the spear during firing permits the spear to be released.
6 Claims, 2 Drawing Figures 1 UNDERWATER COMPRESSED-GAS GUN The object of the present invention is a compressedgas gun for propelling a spear under water.
Underwater compressed-gas guns are known which are composed of a gas tank provided with a valve and a gun body in which the spear is placed, said body being are placed around the barrel.
The other tube, of larger diameter, contains, from the rear to the front, a thrust chamber in which the rear end of the spear is contained; a compressed-gas reserve chamber and an elastic sleeve the inside diameter of which is slightly less than the outside diameter of the spear. This sleeve, together with the second tube, defines an annular space which communicates, via a conduit equipped with a valve, with the compressed-gas tank and, via another conduit equipped with a valve, with the outside.
The opening of the said valve can be controlled by the hunter by means of a trigger. The valve is calibrated and opens if the gas pressure in the gun exceeds a limit value. The said annular enclosure communicates with the compressed-gas reserve chamber located immediately to the rear of the elastic sleeve by orifices equipped with nonreturn valves.
The gun comprises at the rear a thrust chamber separated from the reserve chamber by a tight packing. This thrust chamber communicates with the outside through an orifice provided with a floating valve the head of which is located on the inside of the thrust chamber.
The rear end of the gun is closed by a threaded plug which is screwed onto the tube. This plug is pierced throughout by at least one channel which communicates with the orifice equipped with the said floating valve. Within the plug there is arranged a cavity in which the guide rod of the floating valve slides. When the hunter screws this plug in sufficiently, the rod of the valve presses against the rear part of the said cavity or to a shoulder in such a manner that the valve is locked in open position. This is the safety position.
FIG. 1 is a cross-section through a gun in accordance with the invention.
FIG. 2 is a cross-section on a larger scale through different parts of FIG. 1. r
A gun in accordance with the invention comprises a compressed-gas tank 1 1 equipped with a valve 10. The gun barrel is composed at the front of a tube 1 the inside diameter of which is slightly greater than the outside diameter of the spear 2. 7
Around the front end of the barrel there are placed a slide 3 and a stop 3a which is fastened to the barrel. The slide 3, upon moving forward, strikes against the ring 4 of the spear and causes the ejection thereof.
The rear part of the gun is formed of a second tube 5 the diameter of which is greater than that of the tube 1.
Within the tube 5 there is arranged, at the front, a sleeve 6 of an elastic material held by two rings 7 fastened to the tube 5. The two rings 7 have an inside diameter equal to that of the tube ll. The inside diameter of the sleeve 6 is less than that of the spear 2 which is to be force-fitted. Once fitted, the spear is held in the gun by the elastic force of the sleeve 6. The sleeve 6 together with the tube 5 defines an annular space 8. This space communicates via the orifice 9 through the valve 10 with the compressed-gas tank 11. It also communicates via the channel 12 with the outside through a nozzle 113 which is closed by a valve M. The valve 14 is held closed by the spring 15 housed in the handle of the gun. The valve 14 opens automatically when the pressure in the enclosure exceeds a limit value. The opening of the valve 14 can be controlled by the hunter by means of the trigger 16 in order to discharge the spear.
The annular enclosure 8 communicates via channels 17 with the reserve chamber 18 located at the rear of the sleeve 6. These channels are equipped with nonreturn valves 19.
The rear end of the arrow is held in the thrust chamber 20 which is separated from the reserve chamber by a sealing ring 24. The sealing ring 24 is housed in a groove cut in the part 21 screwed into the tube 5. The
part 22 which is screwed into the thrust chamber 20.
The rear end of the gun is closed by a threaded plug 23. A floating valve is arranged at the rear of the thrust chamber, the head 26 being placed in the chamber 20. This valve is extended by a rod 27 and by a shank 28 which is housed in a cavity provided in the plug 23. Channels 25 pass from one end of the plug 23 to the other.
When the plug 23 is screwed in entirely, it rests against the shank 28 of the valve and the valve is maintained open. This is the safety position.
Upon unscrewing the plug 23, the floating valve 26 is freed.
Before introducing the arrow into the gun, the hunter screws in the plug 23. When he introduces the spear, the water contained in the thrust chamber is discharged through the channels 25. When the hunter wishes to cock the gun, he opens the valve 10 for a certain period of time while leaving the plug 23 screwed in. If the sealing ring 24 is damaged, there is a leak of gas to the rear which warns the hunter.
Before starting to hunt, the hunter unscrews the plug 23. The valve 26 is then freed. At the time of the departure of the spear, as long its rear end has not passes the sealing ring 24, the valve 26 remains open, which avoids the chamber 20 being placed under vacuum. As soon as the rear end of the arrowhas passed the sealing ring 24, the chamber 20 is under pressure and the valve 26 closes, which avoids losses of compressed gas.
The operation of the gun is as follows. The hunter introduces the spear into the gun through the barrel, forcing it in order to overcome the elastic force of the sleeve 6.
In order to cock the gun, the hunter opens the valve 10. The pressure is built up in the annular space 8 and in the reserve chamber 18. The hunter again closes the valve 10. The pressure in the space 8 maintains the sleeve applied with force against the arrow and the sleeve serves as tight joint between the reserve chamber 18 and the barrel.
part 21 defines the In order to effect the departure of the arrow, the hunter presses against the trigger 16 and causes the decompression of the annular space 8. The compressed gas contained in the reserve chamber 18 escapes, passing between the sleeve 6 and the spear, and it deforms the sleeve 6. The water contained in the barrel is expelled and it pushes the slide 3 which causes the ejection of the spear. When the rear end of the spear has passed the sealing ring 24, it is subjected to the thrust resulting from the expansion of the gas contained in the reserve chamber.
1. A compressed-gas gun for propelling a spear under water which comprises:
barrel means mounted to one end of said body, said barrel and body being adapted to receive the shaft of a spear;
compressed-gas storage means mounted to said body;
valve means fluidly connecting said storage means with the interior of said body;
said body having interiorly from rear to front, a first chamber having sealing means adapted to receive in gas tight relationship the end of a spear shaft, a compressed-gas reserve chamber forwardly of said sealing means, and a coaxially mounted elastic sleeve having an interior diameter of a size to grip the shaft of a spear;
said barrel slidably supporting adjacent its front end a tubular slide means adapted to engage the end of a spear to partially eject the spear;
stop means on the end of said barrel to limit the forward movement of said tubular slide means; and
trigger means mounted to said body to release said spear.
2. A gun according to claim 1, wherein said sleeve and said body define an annular chamber in fluid communication with said compressed-gas storage means, and said body includes means for communicating said annular chamber with the exterior of said gun.
3. A gun according to claim 2, wherein said communicating means comprises a channel normally closed by a calibrated valve and being openable by said trigger means to cause the release of a spear.
4. A gun according to claim 2, wherein non-return valves are positioned between said annular chamber and said reserve chamber, said non-return valves permitting fluid flow from said annular chamber to said reserve 5. A gun according to claim 1, wherein said sealing means comprises a sealing ring cooperative with the shaft of a spear to seal said first chamber from said reserve chamber; and manually-operable floating valve means within said first chamber rearwardly of said sealing means.
6. A gun according to claim 5, which further includes a plug threaded in the rear end of said body in such manner as to permit selective insertion thereof, said plug defining at least one orifice extending therethrough and a cavity adapted to receive a guide rod of said floating valve means, a wall of said cavity being dimensioned to engage said guide rod when said plug is fully inserted to maintain said floating valve means in opened position.
UHILLU DLALIJD Iltllbfil urrlun CERTIFICATE OF CORRECTION Patent No. 3,735,747 Dated y 29, 1973 Inventor(s) Jean Barjav el It is certified the}: error appears in the above-identified patent "and that said Letters Patent are hereby corrected as shown below:
Col. 4, line 16, a fter "serve" add chamber.-L
Signed and sealed this 201; day of November 1973.
(SEAL) Attest: EDWARD MaFIiETCHERi-J'R. RENE n C'IIEGTMEYER Attetihg Gffieeic Acting Cbiiihiissibher of Patents foRM pooso uo-ss) USCOMM-OC even-was