Multishot Underwater Survival Gun

The field of the invention pertains to hand held underwater weapons and, in particular, to underwater multishot spear guns. Such guns generally comprise a head having one or more firing chambers and a long shaft handle. The guns are carried by divers in waters where shark attack is a possibility. Shells are fired by impacting the head against the target, typically an umnderwater predator such as a shark.

Single chamber impact actuated guns are disclosed in U.S. Pat. No. 3,274,936, U.S. Pat. No. 3,664,052 and U.S. Pat. No. 4,100,692. These patents disclose various means for constructing the chamber and, in particular, the firing mechanism. Unfortunately, if the first shot is not successful, reloading underwater in sufficient time to avert disaster may not be possible.

Because of the need for repeat shots without reloading, multishot weapons have been developed. U.S. Pat. No. 3,616,561 discloses a multiple long bore gun wherein the barrels are rotatable in the manner of a long cylinder and the firing pin is trigger actuated. Such a gun is unduly complicated and unwieldy.

A multiple shot gun with a rotatable cylinder head for firing bullets is disclosed in U.S. Pat. No. 3,494,060. Impacting the head against a target causes firing of a bullet and indexing the next chamber and bullet into position. U.S. Pat. No. 3,545,117 and U.S. Pat. No. 3,721,031 each disclose rotatable cylinder heads with large chambers for shotgun shells and fired by impact. Although multiple shot capability is provided, the cylinders cannot easily be replaced underwater.

With a view toward a more convenient and effective multishot underwater gun wherein the cylinder can be easily exchanged underwater, applicant has invented the following device.

The new underwater survival gun comprises a multi-chambered head attached to a long handle. The handle includes a rotatable section connected to the cylinder in the head to manually index the cylinder, sequentially chamber by chamber, into the firing position.

The cylinder is retained in the head by spring urged latching arms that are closed into position by a cylinder lock ring. A partial turn of the cylinder lock ring permits the release of the arms and the cylinder for quick and easy replacement both above and under water.

The chambers are formed by sleeves in the cylinder each having at least a portion of the sleeve outside open for engagement by the arms. The engagement with the arms provides index positions to align the chambers sequentially in the firing position. The engagement is preferably formed to also provide intermediate safety positions for the cylinder.

The connection of the cylinder to the handle includes a spring urging the cylinder forward from the handle. The gun is thus fired by impacting the head on the target causing the cylinder to move backward and a shell in the chamber aligned for firing to contact a firing pin.

FIG. 1 is a side view of the underwater gun;

FIG. 2 is an exploded view of the head of the gun;

FIG. 2A is a detail of a latching arm in the head of the gun;

FIG. 3 is an exploded view of the tail stock of the gun;

FIG. 4 is a front end view of the cylinder;

FIG. 5 is a rear end view of the cylinder;

FIG. 6 is a front end veiw of the back plate; and

FIG. 7 is a side view of the back plate.

Illustrated in FIGS. 1, 2 and 3 is the underwater gun comprising a head generally denoted by 10 and a tail stock or spear handle generally denoted by 12. The tail stock includes two external tubes 14 and 16 about three quarters of an inch in diameter and a total of about three feet in length. The tube 14 is rotatable relative to tube 16 to rotate the cylinder 18 in the head 10. The exterior of the tube 14 is knurled to provide a suitable hand grip.

Within the tail stock is an end plug 20 and a handle sleeve 22 both attached to the tube 14. Within the tube 16 and attached to the handle sleeve 22 is a first main shaft 24. At the other end of the first main shaft 24 a second main shaft 26 is attached. At the other end of the second main shaft 26 a bushing 28 surrounds the attachment of a bifurcated rod 30 which extends into the center hole 32 of the cylinder 18.

The tail stock tube 16 is attached by a main housing connector 34 to the tubular extension 36 of the back plate 38 of the head 10. The back plate 38 is suitably bored at 40 to provide support for the bushing 28 and cylinder 18. The external surface of the collar 42 of the back plate 38 is threaded for the engagement of the knurled locking ring 44 and collar 46. Offset radially from the centerline of the gun and permanently attached to the back plate 38 is a firing pin 48. The firing pin determines the firing position for each cartridge chamber 50 of the cylinder 18.

Within the cylinder 18 is a transverse pin 52 engaging the slot 54 in the bifurcated rod 30. Thus, the cylinder 18 is caused to rotate upon rotation of the tube 14. Engaging the tips of the bifurcated rod 30 is a cylinder extension stop 56. A coil spring 58 engages the stop 56 and the nose piece 60 threaded within the nose 62 of the cylinder 18. As assembled the spring 58 urges the cylinder away from the back plate 38. Upon impact with a target the cylinder 18 is forced toward the back plate 38 and firing pin 48.

As shown in FIGS. 2, 6 and 7 a pair of flexible arms 64 are pivotably attached at 66 on opposite sides of the back plate 38 in slots 68. The arms are urged outwardly out of disengagement with the cylinder 18 by a pair of springs or ball detents 70 set in holes 72 in the back plate 38. The lock ring 44 flange internal surface 74 retains the arms 64 inward in engagement with the cylinder 18. The inward engagement, however, retains sufficient freedom in the flexible arms 64 to permit indexing of the cylinder 18.

As shown in FIGS. 2, 4 and 5 the chambers 50 in the cylinder 18 are formed by steel sleeves 76 insertd in an aluminum cylinder. The sleeves 76 are partially exposed at 78 by the circumferential groove 80 in the cylinder 18. To retain the cartridges in the chambers a shell retainer 82 is threadably engaged to the cylinder 18 at 84. The shell retainer 82 is formed with a plurality of holes 86 of a diameter less than the cartridges but of sufficient size to permit entrance of the firing pin 48. The ball detent 88 in the cylinder 18 engages a hole 90 in the shell retainer 82 only when the shell retainer 82 is fully threaded on the cylinder 18 thereby assuring that the cartridges are properly retained in the chambers 50 and the holes 86 in the shell retainer 82 are properly aligned with the chambers 50.

The forward ends 92 of the arms 64 are formed concave 94 as shown in FIG. 2A to engage the convex exposed surfaces 78 of the chamber sleeves 76. Sequential engagement of the arms 64 with the chamber sleeves 76 as the cylinder 18 is indexably rotated, sequentially aligns the chambers 50 with the firing pin 48. Indexing the cylinder into positions where the arms 64 engage the cylinder 18 between the chamber sleeves 76 as shown ghosted in FIG. 4 provides safety positions for the cylinder and gun.

The cylinder 18 may be easily removed and replaced by another cylinder by rotating the lock ring 44 until the slots 96 align with the arms 64 thereby allowing the ball detents 70 to urge the arms 64 outwardly out of engagement with the circumferential slot 80 and the chamber sleeves 76. The cylinders can then be slid from the bifurcated rod 30 and another cylinder 18 with fresh cartridges inserted on the rod 30. The arms 64 are closed and the lock ring 44 rotated to retain the arms 64 closed. Thus, the cylinders 18 can be preloaded with cartridges and easily replaced underwater if necessary.