1. Field of the Invention
The invention pertains to the field of toy guns that generate bursts of air to function. More particularly, the invention pertains to improvements in aiming accuracy and to safety of the toy guns and targets for use with these guns.
2. Description of Related Art
Conventional toy guns that shoot solid projectiles (for example, plastic balls) can be dangerous, and both these guns and guns that shoot water are unsuitable for indoor use in ordinary living areas where they may damage furniture and other household items.
Toy guns that shoot air provide fewer personal injury risks and can be suitable for indoor use. For example, U.S. Pat. No. 4,157,703 to Brown et al. (1979) shows a toy gun, in which an elastic diaphragm is deflected by an impulsive force produced by a trigger mechanism, producing a burst of air that can be used to knock down small targets at short range.
A different class of toy air gun generates vortex rings of air. Unlike air blasts from the Brown et al. device, vortex rings are interesting objects in and of themselves. They are highly stable and can travel great distances from their sources while maintaining their shape and intensity before dissipating. Vortex rings are localized disturbances in the air that propagate through the air with a well-defined speed. When the vortex rings strike an object they exert a brief impulsive force due to their forward motion and the rapidly circulating air within them. Consequently, they behave very much like solid projectiles, but without their associated risks.
Toy guns for producing vortices in air have been patented. U.S. Pat. No. 1,473,178 to W. R. Dray (1923) describes a gun in which a flexible diaphragm is retracted by hand and then released, blowing air out a cylindrical tube. This design is very similar to that of the “AirZooka” currently marketed by Zero Toys of Concord, Mass. U.S. Pat. No. 2,534,398 to Beathan (1950) describes a vortex gun with a spring-loaded diaphragm and a circular aperture. U.S. Pat. No. 2,543,651 to Weiss (1951) uses a piston to strike a flexible membrane and force air out a circular aperture. U.S. Pat. No. 2,614,551 to Shelton (1952) describes several configurations of a toy vortex gun, generally consisting of a flexible or rigid diaphragm and mechanisms for displacing it to shoot a burst of air through a circular aperture. U.S. Pat. No. 2,879,759 to Webb (1959) describes a variant on Shelton's basic designs. These guns have their own dangers, including the possibility of objects placed in the barrel being projected out, and of excessive pressure causing damage to, e.g., ears if the output opening is blocked. Other examples include U.S. Pat. No. 1,611,533 by Kirsten (1926); U.S. Pat. No. 1,926,585 by Gibbons (1933), U.S. Pat. No. 2,846,996 to Drynan (1958), U.S. Pat. No. 3,117,567 to Allen (1964), U.S. Pat. No. 3,342,171 to Ryan et al., (1967), U.S. Pat. No. 3,465,741 to Daniel et al. (1969), and U.S. Pat. No. 3,884,471 to Maurer et al. (1975).
U.S. Pat. No. 4,157,703 to Brown et al. (1979) describes safety features for toy air guns. A grid placed in front of the air-displacing member prevents objects placed inside the gun from being projected outward. A vented auxiliary parabolic cone on the outlet of the gun, whose outlet diameter is approximately equal to the diameter of the muzzle opening, provides pressure relief in the event that the outlet of the gun is blocked by, e.g., a child's ear. However both the positioning and patterning of the protective grid, the shape of the auxiliary cone, and the diameter of its opening are such as to dramatically reduce vorticity at the gun's output and the power of the vortex rings it produces, so that this design is a conventional air gun rather than a vortex ring gun. (This is in fact evident from the patent, which states the gun produces puffs of air and makes no mention of vortex rings.) This gun is also designed for relatively short-range targets (up to 8 feet), where airflow at the target will have a large non-vortex component so that the “projectile”-like behavior of any vortex ring is obscured.
Targets for toy air guns have been discussed in U.S. Pat. No. 1,473,178 to Dray (1923), U.S. Pat. No. 1,926,585 to Gibbons (1933), U.S. Pat. No. 2,534,398 to Beathan (1950), U.S. Pat. No. 2,614,551 to Shelton (1952), U.S. Pat. No. 3,884,471 to Maurer et al. (1975), and Des. 259,335 to Gillespie (1981). None of these targets are particularly interesting or entertaining, especially when compared with target-type activities possible with guns that shoot solid projectiles.
U.S. Pat. No. 2,628,450 to Shelton (1953) describes a variant on the vortex gun, which fills the chamber with smoke, so as to render the vortex visible (a smoke ring gun.) Subsequent patents for smoke ring guns include U.S. Pat. No. 2,855,714 to Thomas (1958), A very similar device described in U.S. Pat. No. 6,421,502 B1 to Aronie et al. (2002) is currently marketed as the “Zero Blaster” by Zero Toys. A disadvantage to smoke ring guns is that the air exit velocity and thus the vorticity and vortex velocity must be small; otherwise, the particulates cannot follow the vortex ring's motion and the “smoke ring” disappears. Consequently, they are unsuitable for target-type activities where an appreciable impulse must be delivered to the target to register a hit. Another disadvantage is that the materials used to make the rings visible are all irritants and many are toxic.
A major deficiency of all of these air guns is that they are extremely difficult to accurately aim. Unlike conventional toy guns, relatively large barrel diameters and air collimating or vortex producing apertures (typically 6–12 inches and 2 inches, respectively) are required to produce the strong air displacements and/or strong vortex rings capable of producing visible effects on targets at significant distances. Aiming sights placed on the outside of the barrel are far from the gun's axis, and the parallax between the sight line and the air burst/vortex ring trajectory and resulting aiming errors are large at all target distances, especially at larger distances where the air motion is due almost entirely to the moving vortex ring and where the striking, projectile-like behavior of the vortex ring is most apparent. Deviations in motion of the air-displacing membrane or piston from perfect cylindrical symmetry about the bore axis (as in, e.g., the AirZooka) also produces aiming errors and irreproducibility in air puff/vortex ring strength. No doubt it is for this reason that the commercially marketed vortex gun AirZooka doesn't include targets, and that earlier commercial air gun products included only very large, curtain-like targets that were easy to hit.
The invention consists of air gun or vortex ring gun modifications to realize a gun with much greater accuracy in target-type activities and with improved safety, as well as targets specifically designed for use with this class of gun. These improvements greatly increase the play value of an air/vortex ring gun.
The gun uses an improved aiming system obtained by making the center of the bore transparent along the entire length of the gun. Together with the transparent nature of the gun's projectile, this allows a coaxial sight down the center of the gun's bore. The gun also uses a precise air displacement system and design features to maintain cylindrical symmetry in the airflow. These features dramatically improve targeting accuracy, especially for guns with large barrels and air displacements that produce the most intense vortices.
The gun described in detail here is designed to produce strong vortex rings rather than air puffs since these have more desirable properties in target-type activities, but the same basic principles and designs outlined here apply to both kinds of guns. The gun described here has an output aperture design to maximize vortex ring strength and velocity for a given air displacement in the bore, making it suitable for target-type activities with targets placed from small to large distances (at least 15 feet) away from the gun. At large distances, the air forces at the target are due almost entirely to a localized vortex ring (the blast of air that accompanies the vortex out of the gun's aperture is dissipated), maximizing the pleasing projectile-like behavior at the target.
The gun incorporates an improved safety screen to prevent objects inserted into the gun barrel from being projected outward, and an improved safety guard at its output that provides pressure relief in case the output opening is blocked while maximizing vortex ring strength.
The gun may have multiple “loaded” positions that produce different air displacements, allowing the vortex ring intensity and velocity to be varied. The vortex ring velocity can be made much slower than that of projectiles shot by conventional toy guns, allowing dramatic time delays (up to a few seconds) between firing and hits by the invisible vortex (reminiscent of “photon torpedos”.) Vortex velocity can also be changed by using interchangeable output apertures of different sizes. These improvements realize a vortex ring gun that is safe and entertaining to use and highly effective in target type activities.
The same design features described here can be used to improve guns designed to shoot smoke rings. A different kind of vortex ring gun, based on smoke ring guns, shoots vortex rings containing odor molecules produced by injecting a mist or spray containing the molecules into the gun barrel before firing. This gun allows a localized odor to be delivered to a target.
Several kinds of target well suited for use with accurate vortex ring guns are described: targets that are knocked or bent over, simulating a cartoon character's response to being shot; targets that spin or rotate about a horizontal or vertical axis normal to vortex direction; and targets that spin about an axis parallel to the vortex direction. With appropriate decoration, these targets provide a range of entertaining play possibilities that highlight the unusual features of these guns.
The barrel in which the piston slides has vent holes 7 to allow air to escape and enter the barrel as the piston moves. The rear end of the barrel is sealed by a transparent window 8 made of, for example, a transparent plastic, that can be marked as shown in
The piston is guided in its path by the cylindrical barrel 52 in which it resides, which ensures that the motion of the piston face is purely axial. Additional guides (e.g., of a tongue and groove type) running parallel to the barrel's axis on the piston and barrel can be used to eliminate any rotation about the axis of the piston. Alternatively, the piston can be eliminated and an air-displacing member can be guided to move in a purely axial direction by a “tongue and groove” mechanism around its periphery, or by guiding rods that project along the barrel axis forward or rearward from the air-displacing member at any radius from its center, and that slide through guides or channels within the barrel.
The safety screen 5 has a cylindrically symmetric array of openings and a large open area fraction, as shown in
The aperture containing member 14 defining opening 13 is transparent (for example, made of a transparent plastic) to allow easy location of the target, and has a very small thickness at the aperture edge, thereby providing maximum conversion of the forward motion of the air into a vortex ring 15 according to well established principles of fluid mechanics. For sturdiness the aperture-containing member 14 may be thicker at its outer edges. This member can be removable, allowing apertures with different diameter openings to be used, providing vortex rings of different size, strength and speed.
The safety guard 16 is a curved continuation of the gun barrel past the aperture containing member 14. The inside diameter at its outlet is larger than the vortex ring diameter so that it does not interfere with the ring, but may be smaller than the diameter of a child's head. Cylindrically symmetric vents 17 running circumferentially in this guard 16 relieve pressure if the guard opening is blocked. The gun is supported by two hands using hand holders 18. U.S. Pat. No. 4,157,703 to Brown et al. (1979) describes a vented safety guard that curves in the opposite direction to 16 and that has a diameter smaller than the vortex diameter. Consequently, this safety guard largely destroys the vortex ring component of the exiting air, and so functions as a traditional air gun (as claimed in the patent) rather than a vortex ring gun.
To aim the gun, the user looks through the transparent windows 8 and 6, the transparent safety screen 5 and the circular aperture 13 of the transparent aperture—defining member 14 at the target, aligning the crosshairs in windows 8 and 6, the crosshairs 12 in the safety screen and the circular aperture 13 on the target. Thus, targeting is performed by viewing directly along the axis of the gun barrel, and is assisted by the cross hairs on the rear window and the safety screen.
The cylindrically symmetric design and the purely axial and reproducible motion of the piston 1 ensures that the vortex ring is accurately and reproducibly projected along the same axis. Consequently, the air displacement chamber diameter can have any size (from a few inches to a few feet or more) and still allow accurate targeting at arbitrary distances from the target. To maximize the viewable angle, the piston diameter should be large and its length and the overall length of the gun kept reasonably short. As with telescopes, optical elements can be inserted to increase the viewing angle, and a 90-degree reflector inserted to the right of or in place of the window 8 to allow aiming by viewing downward into the reflector.
In the alternative embodiments shown in
Other mechanisms can also be used to create air displacements. For example, the elastic members can be replaced by an electromagnetic coil and magnets to produce an axial electromagnetic drive, as in a loudspeaker.
The targets in
Other standard fan configurations may be used, such as the spiral or screw-type fan 47 in
The present invention comprises a new approach to vortex ring guns. Its particular advantage is that aiming is performed by directly viewing along the axis along which the vortex travels, and that the air flow within the gun is highly reproducible and cylindrically symmetric, which makes the gun suitable for target-type activities requiring high accuracy. Accurately aimable guns of arbitrary size may be made by this approach. The gun also includes important safety features to prevent objects placed inside the barrel from being projected outward and to protect against, e.g., ear damage if the vortex exit opening is blocked. Both are designed to maximize the exiting vortex's strength and preserve the axial symmetry of the airflow. In addition, several examples of targets are provided that take advantage of this vortex gun's high aiming accuracy and that greatly increase its play value.
Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
This application claims an invention which was disclosed in Provisional Application No. 60/480,487, filed Jun. 21, 2003, entitled “Improved Toy Guns With Targets.” The benefit under 35 USC §119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
1473178 | Dray | Nov 1923 | A |
1611533 | Kirsten | Dec 1926 | A |
1926585 | Gibbons | Sep 1933 | A |
2534398 | Beathan | Dec 1950 | A |
2540060 | Szantay | Jan 1951 | A |
2543651 | Weiss | Feb 1951 | A |
2614551 | Shelton | Oct 1952 | A |
2628450 | Shelton | Feb 1953 | A |
2846996 | Drynan | Aug 1958 | A |
2855714 | Thomas | Oct 1958 | A |
2879759 | Webb | Mar 1959 | A |
3117567 | Allen | Jan 1964 | A |
3342171 | Ryan et al. | Sep 1967 | A |
3465741 | Daniel et al. | Sep 1969 | A |
3884471 | Maurer et al. | May 1975 | A |
4157703 | Brown et al. | Jun 1979 | A |
D259335 | Gillespie | May 1981 | S |
6421502 | Aronie et al. | Jul 2002 | B1 |
6694658 | Marsac | Feb 2004 | B1 |
6983742 | Jordan et al. | Jan 2006 | B2 |
20030034020 | Irizarry et al. | Feb 2003 | A1 |
Number | Date | Country | |
---|---|---|---|
20040255922 A1 | Dec 2004 | US |
Number | Date | Country | |
---|---|---|---|
60480487 | Jun 2003 | US |