March 23,, 1971 KENSUKECHIBA COMPRESSED GAS GUN AND VALVETHEREFOR 3 Sheets-Sheet 1 Filed Jan. 28, 1969 71 dew Mar 1971 KENSUKE CHIBA COMPRESSED GAS GUN AND VALVE THEREFOR Filed Jan. 28, 1969 3 Sheets-Sheet 5 Fig 7 Fig. 8 v30 1 23 34 5 310 39 27 2 2 I v W W I/vVf Vfe KENSI/(f (SH/8A ATTORN-YS United States Patent "ice 3,572,310 COMPRESSED GAS GUN AND VALVE THEREFOR Kensuke Chiba, 8, Z-chome, Yotsuya, Shinjuku-ku, Tokyo, Japan Filed Jan. 28, 1969, Ser. No. 794,669 Claims priority, application Japan, Feb. 2, 1968, IS/66,741; Mar. 27, 1968, 43/19,436 Int. Cl. F41b 11/06 US. Cl. 124-11 6 Claims ABSTRACT OF THE DISCLOSURE A gas operated gun with a barrel defining a rearward extension including a widened portion accommodating a bolt and a valve. The bolt is spring urged to open the valve at the end of the extension which in turn allows compressed gas to return the bolt to a forward position. At the return position of the bolt, a gas passage extending through the bolt is opened and allows the gas to expel a pellet from the barrel. A magazine for the gun is an elongated container accommodating a stack of pellets, and has a resilient tongue for inserting into the housing enclosing the barrel; the tongue normally holds the topmost pellet in the magazine; but when inserted in the housing, the tongue is cammed outwardly to release the topmost pellet.
SUMMARY OF THE INVENTION This invention relates, in general, to the construction of guns and a magazine therefor, and in particular, to a new and useful fluid pressure operated gun which includes a bolt which is slidable in the barrel of the gun and which defines a fluid pressure gas passage which communicates at the rear portion of the barrel with a fluid under pressure which provides the propelling force for the gun projectile; and also to an improved magazine construction for such guns.
 The present invention is particularly directed to the construction of a gun such as a rifle or a piston which may be operated by a fluid pressure force which may be obtained for example, from a container of a pressurized mechanism such as a carbon dioxide container. The construction is an improvement over the prior art, particularly in respect to the simple and easy means for conveying pellets or projectile elements to the bore of the gun in front of a movable bolt having a gas passage which is communicated during each reciprocating cycle with a supply of gas under pressure to projectile the pellet out of the gun barrel and to recock the gun. The construction is such that the bolt may be easily cocked initially by engagement of a bolt handle secured thereto. The bolt sliding operation after the trigger is released will be effective to communicate the desired gas pressure to the bore of the barrel for firing the pellet during each subsequent release of the trigger.
 In accordance with a feature of the invention the pressurized medium is employed to displace the bolt back into a cocked position and to thereafter provide the, fluid gas for propelling the projectile out of the barrel. This is accomplished by constructing the bolt so that its end face will be exposed to the pressurized medium initially and will be caused to advance in a direction parallel to the bore of the gun barrel up to a point at which it engages within a trigger latch mechanism and it compresses a bolt spring. The bolt spring provides the actuating force for initiating the backward movement of the bolt to open a valve for communicating the rear chamber with the pressurized medium.
 The magazine which is engaged in a transverse channel which communicates with the barrel bore at a location ahead of the bolt when it is in a retracted position in- 3,572,310 Patented Mar. 23, 1971 cludes spring means for automatically feeding the next projectile upwardly into the bore ahead of the sleeve. The arrangement provides a simple and inexpensive automatic mechanismfor the automatic firing of a plurality of pellets or similar projectiles.
 Accordingly, it is an object of the invention to provide an improved gun construction having a slidable hollow bolt which communicates during its slidable movement with a source of fluid under pressure and which is moved by this fluid pressure in an advancing direction to again cock the firing mechanism and to provide a propelling gas for propelling the projectile out of the barrel core.
 A further object of the invention is to provide a gun construction providing a simple means for feeding pellets into a barrel and for firing the pellets from the barrel and for automatically recocking the device during each firing cycle.
 A further object of the invention is to provide a gun construction which is simple in design, rugged in construction and economical to manufacture.
 The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:
 FIG. 1 is a top side perspective view of a magazine constructed in accordance with the invention;
 FIG. .2 is a longitudinal sectional view of the magazine indicated in FIG. 1;
 FIG. 3 is a transverse section of a gun barrel having a magazine therein constructed in accordance with the invention;
 FIG. 4 is an enlarged partial bottom plan view of the gun indicated in FIG. 3;
 FIG. 5 is a partial longitudinal vertical sectional view of a gun constructed in accordance with the invention; and
 FIGS. 6, 7 and 8 are views similar to FIG. 5 showing the operating parts of various positions of operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, in particular, the invention embodied therein in FIGS. 1 to 4 comprises a magazine for cartridges or pellets which includes a block-shaped container 1 having a closed end 1a and an oppositeopen end 6 into a portion of which projects a resilient tongue ortab 8. Projectiles such aspellets 3, are loaded into theopen end 6 by depressing the tongue outwardly. Thepellets 3 rest on a follower orsupport 4 which is biased toward the open end by aspring 2 arranged between the bottom la and thefollower 4. A claw or tooth projection 7 on thetongue 8 holds thepellets 3 within the magazine against the force of thespring 2. Agun barrel 20 is provided with a bottom magazine receiving frame 11 which is arranged around the lowermost opening of amagazine channel 15. The frame 11 carries atransverse stopper 13 on a central receivingflat spring 12 which is deflected outwardly by an insertion of the magazine but which engages in a groove 10' defined in a side wall of the magazine when the magazine is properly positioned in respect to the gun. Thetongue 8 is pointed so that it will be deflected by a nose or projection '14, defined at the upper (inner) end of the barrel magazine channel, to
an outward position at which the claw 7 will be released from thepellets 3 to permit their upward feeding movement by thespring 2.
 The magazine advantageously includes anelongated slot 9 defined in a side wall through which a pin orindicator member 5 extends. Indications or markings defined along the length of the slot provide an indication of a number of cartridges within the magazine as shown by the position of thepin 5 which is formed as an extension of a portion of thefollower 4.
 In the firing position indicated in FIG. 3 as each pellet is projected outwardly through the bore of the barrel 20 anew pellet 3 will be fed upwardly by the action of thespring 2 acting on thefollower 4. Thepin 9 will ride upwardly with the follower and thus indicate the number of pellets which remain in the magazine and which have not yet been fired.
 In FIGS. 5 to 8, there is indicated a gun of the type shown in FIG. 3, showing the various positions of the operating mechanism for firing a projectile through a bore 20' of thebarrel 20. In accordance with the invention, the operating mechanism includes a sliding bolt or sleeve member generally designated 29 having a central bore orgas passage 29 therethrough which is concentrically arranged within the bore 20' of thebarrel 20. Thebarrel 20 includes an intermediate recess orspring cavity 23 having aslot 50 through which projects abolt handle 30 of thebolt 29.
 Abolt spring 34 is disposed around thebolt member 29 between the forward end of thecavity 23 and thebolt handle 30 and it is compressed in the cocked position indicated in FIG. 5. In the cocked position anarm portion 36 of atrigger mechanism 35 is engaged against a latching portion 31 of thebolt 29 which is in alignment with thebolt handle 30 to hold the sleeve member in a position at which thefiring spring 34 is compressed. Atrigger spring 38 urges thearm portion 36 into a latching engagement with the latch portion 31.
 When thetrigger 35 is pulled to fire the gun it is rocked about thepivot 37 to bring thearm portion 36 out of engagement with the latch portion 31 so that thespring 34 may relax and drive thebolt member 29 rearwardly. This permits a cartridge orpellet 3 to be moved upwardly by themagazine spring 2 into a position ahead of the sleeve member communicates with atransverse passage 32 at its rear end which in the position indicated in FIG. 5 communicates with an annular gas by-pass 24. In the position of FIG. 6, however, thegas passage 32 is blocked by a narrow gas passage orsealing chamber 25 located at the rear end of thebarrel 20. Thisnarrow sealing chamber 25 communicates rearwardly into agas chamber 27 when aclosing valve 39 is lifted olf its seat against the force of acompression spring 41 tending to hold it on its seat. The lifting is effected by the rearward movement of thesleeve member 29 which contacts avalve stem 40 to effect the lifting of thevalve 39 off itsseat 26. Thegas chamber 27 communicates with amain gas chamber 22 having a gas under pressure such as a C gas, which is supplied, for example, from an inexpensive CO container. The gas flows through a restrictedpassage 21 into theauxiliary gas chamber 27. The gas passages 3-2, 24, 25 and 29' form a passage means for the gas under pressure to flow from thevalve 39 to the bore 20'.
 The opening of thevalve 39 causes a gas flow into thesealing chamber 25 and causes the forward movement of thesleeve member 29 to compress its associatedspring 34 and to move the latch 31 beyond thetrigger arm portion 36 so that it will be re-engaged therewith to recock the gun. At this location the transverse passage will also communicate through theannular passage 24 with the gun under pressure which will be admitted through thegas passage 29 to force the pellet through the barrel board 20' out of the gun toward the target (FIG. 8). The FIG. 8 position corresponds to that of the FIG. position so that the gun is again cocked ready for firing the next round.
What is claimed is:
 1. A gun construction, comprising a barrel having a bore for firing a projectile therethrough, a bolt having a gas passage therein opening into said barrel bore and having a portion thereof movable in said barrel bore, spring means urging said bolt in one direction, means associated with said barrel defining a fluid pressure chamber, trigger means engageable with said bolt for latching said bolt in a position with said spring means biasing said bolt and being releasable to permit said spring means to move said bolt in said one direction, valve means located adjacent said bolt and connecting said chamber to a passage means and being actuatable by movement by said bolt, and said passage means connectible to said fluid pressure chamber by way of said valve means to cause fluid therein to act on said bolt and to move it in a direction opposite to said one direction against the force of said spring means, said passage means upon a predetermined movement of said bolt in a direction opposite to said one direction connecting said gas passage in said bolt to said fluid from said pressure chamber whereby said fluid in said passage means passes through said gas passage to discharge a projectile in the said barrel bore outwardly from the gun.
 2. A gun construction, according to claim 1, wherein said passage means comprises a transverse passage defined in said bolt communicating with said gas passage therein and terminating at the periphery of said bolt, and a gas passage formed by said barrel defining a slide chamber for said bolt including an annular widened portion and an elongated sealing portion which is connectible to said fluid pressure chamber, said transverse passage being covered by said sealing portion when the bolt is located within said sealing portion and preventing the flow of fluid from said pressure chamber through the transverse passage.
 3. A gun construction, according to claim 1, wherein said valve means includes a valve member closing the connection between said means defining a fluid pressure chamber and said passage means and having a valve stem extending outwardly therefrom in the direction of said bolt, said bolt being engageable with said valve stem after release of said trigger means to move said valve member to open the connection between said fluid pressure chamber and said passage means.
 4. A gun construction, comprising a barrel having a forward portion with a barrel bore for firing a projectile therethrough and a rear portion with a rear bore portion leading to a fluid pressure chamber, a valve between said rear bore portion and said pressure chamber, a first spring biasing said valve to a position closing said rear bore portion from said pressure chamber, a bolt having a gas passage therethrough opening at one end into the bore of said barrel, a transverse passage connected to said gas passage adjacent the rear portion of said bolt and terminating in the periphery of said bolt, said bolt having a front portion movable in the bore of said barrel and a rear portion movable in said rear bore of said barrel, said rear bore portion including a widened portion adjacent the forward end thereof and a sealing rear bore portion between the widened rear bore portion and said pressure chamber, said bolt being movable rearwardly beyond said widened rear bore portion to seal the transverse passage therein, a second spring biasing said bolt in a rearward direction, a trigger engaged with said bolt and holding said bolt when the latter is in a position in which it is fully biased by said second spring, said trigger being releasable to permit said bolt to be moved backwardly by said second spring, said valve being movable off its seat by movement of said bolt backwardly to cause gas from said pressure chamber to move through said sealing rear bore passage and act against the end of said bolt to move it in an opposite direction against the force of said second spring, said transverse passage being movable into the widened rear bore portion wherein it is communicated to said sealing rear bore portion at the end of the forward movement of said bolt to cause the gas under pressure from the pressure chamber to flow through the gas passage of said bolt and to discharge a projectile positioned in the bore of said barrel.
 5. A gun construction, according toclaim 4, wherein said valve includes a stem portion extending into said sealing rear bore portion-in a position to be contacted by the end of said bolt.
 6. A gun construction, according toclaim 4, including a handle carried by said bolt projecting outwardly from a side of said barrel.
FOREIGN PATENTS 7/1938 Great Britain 124-11 RICHARD C. PINKHAM,Primary Examiner 10 R. DROR, Assistant Examiner US. Cl. X.R.