Electric resistance heating devices – Heating devices – Vaporizer
Reexamination Certificate
2002-04-22
2004-11-30
Paik, Sang (Department: 3742)
Electric resistance heating devices
Heating devices
Vaporizer
C392S404000, C446S024000
Reexamination Certificate
active
06826355
ABSTRACT:
FIELD OF THE INVENTION
The invention generally relates to apparatus for producing smoke, steam or fog, and more particularly, to a toy gun that produces one or more traveling smoke rings when fired.
BACKGROUND
Various toys are known that utilize smoke, steam, and fog (herein, collectively, “smoke”) generators, and a variety of generators for producing smoke for toys, theatrical productions, and the like are also known. See, e.g., U.S. Pat. No. 3,891,826. Liquid mixtures specifically designed for use in such generators are also known. See, e.g., U.S. Pat. No. 3,342,746.
Toy guns have captured the popular imagination for many years. Metcalf, E. W. and Maresca, F.,
Ray Gun
(1999) Fotofolio, Inc., New York, N.Y. is devoted to one type of toy gun, a ray gun. In particular, smoke-producing toy guns are known. U.S. Pat. No. 2,855,714 describes a toy gun that produces smoke rings through the detonation of percussive caps within the gun casing.
While the visual effects and realism of smoke-producing toy guns are significant advantages, a number of drawbacks have limited their commercialization. For example, many prior smoke generators for toys employ mixtures that are not always completely safe. In particular, many oils and oil-based mixtures for making smoke have not been approved for human use. Children may be especially prone to injury from exposure to or mishandling of such fluids, or to heaters used to vaporize liquids to make smoke.
Many prior generators, such as those employed in model railroads, have an open smoke producing device, usually a chimney on an engine, that operates continuously. This arrangement is not conducive to producing smoke rings. It also can be sensitive to orientation—a smoke generator for a fixed, upright smokestack on a model train may not function, or function well, when used in a toy that may assume orientation other than upright. Further, continuous smoke production and the power requirements of such production also militate against the portability of the toy or other device using smoke.
Prior toy guns have used detonation of percussion caps to make smoke. This arrangement is portable and does not require electrical power, but it clearly may not be suitable for use by or near children because of the harmful percussion cap explosions. Percussion caps also produce the noise of a cap explosion, which may be a negative attribute to many.
U.S. Pat. No. 3,342,746 to Seuthe discloses oil-based fluids and a generator for producing smoke. As noted above, such fluids may not be completely without adverse health reactions, particularly when used in closed rooms. In particular, exposure to such fluids in aerosol form can produce significant eye, nose and throat discomfort.
A later Seuthe patent, U.S. Pat. No. 3,891,826, describes a smoke generator that relies on a capillary action to draw the liquid from a central, open-top reservior to a heated region where it vaporizes to provide a smoke or fog. Such generators require an upright orientation for optimal use (due to the effect of gravity on a capillary action that feeds fluid to a resistance heater) and to avoid fluid loss, e.g., due to an outflow from the fluid reservoir. Also, use of electrical resistance wires or coiled wires in many prior generators to vaporize a fluid has presented unacceptable power requirements for portable devices operated with batteries. With model railroads, in contrast, power is typically supplied by household electrical current through a step-down transformer. Further, the narrow clearances and related manufacturing requirements make the Seuthe generator comparatively difficult to manufacture.
It is therefore a principal object of this invention to provide a smoke generator that is portable, safe, fast-acting for non-continuous operation, has comparatively low power requirements, and is substantially orientation insensitive.
Another principal object of this invention is to provide a portable, battery-powered smoke-ring gun that uses electrical resistance heating to produce the smoke and a mechanical heater accessory that significantly enhances the efficiency and volume of the smoke production.
A further object is to provide a smoke ring gun with the foregoing advantages of the smoke generator of the present invention that also has a favorable cost of manufacture.
A still further object is to provide a smoke ring gun with the foregoing advantages that can generate smoke from a water-based liquid.
SUMMARY OF THE INVENTION
The present invention provides apparatus for producing smoke and a toy gun that fires to produce smoke in a traveling ring shape, and in particular is capable of producing a succession of smoke rings traveling from the gun in its direction of aim. A particular toy gun includes a smoke chamber fed by an electrical resistance smoke producing generator. The chamber has an elastic, edge-mounted diaphragm, or equivalent moveable member, that co-acts with the chamber and an outlet orifice formed in a front wall of the chamber to produce the smoke rings. The smoke generator used in the gun is preferably the smoke generator of the present invention. The generator and toy gun can operate with water-based smoke-producing liquids.
The invention includes a smoke generator that includes:
a) a supply tank that holds the liquid,
b) a source of variable fluid pressure (e.g. air) in sealed fluid communciation with the supply tank for increasing and decreasing fluid pressure in the tank to feed the liquid to and from a heating unit;
c) a first tube with a first end entering into the supply tank, and a second smoke outlet end;
d) a heater positioned at least partially within the first tube for vaporizing the pressurized liquid driven by an increase in the pressure into a narrow annular region between the heating element and the surrounding tube; and
e) a spacer that secures a generally uniform radial spacing along the annular region between the outer-surface of the heater and the inner surface of the first tube.
The spacing is such that the pressure increase feeds the fluid to a region adjacent the heater on rapid vaporization, but does not usually overflow the tube, or have a sufficient thermal mass that rapid vaporization of the liquid is difficult. Typically, the heater is an electrical resistance wire that is coiled. When used in a toy gun of the present invention, the variable fluid pressure source is preferably a bulb made from a pliable material, such as rubber, or the like.
The resistance coil is preferably sealed within a heat conductive tube, e.g., a glass tube. In most invention embodiments, the heating element will be suspended in the first tube, usually by means of one or more lead wires to the electrical resistance wire. Also in the preferred form, a second metal tube concentrically surrounds the first tube for mechanical protection and insulation. Overflow and condensate that flow to the bottom of the generator are drained to a closed collection compartment.
A spacer, preferably in the form of a wire that is spiral wrapped around the glass envelope of the heater, maintains a generally uniform, circumferential spacing between the glass envelope and the surrounding first tube. The diameter of the wire is in the range of about 25 to about 75% of the width of the annular gap when the heater is centered in the first tube. For a circumferentially uniform gap of about 0.004 inch (measured radially), the wire preferably has a diameter of about 0.002 inch. The width should also be sufficient not only to control the uniformity of the spacing, but also to force the fluid flowing over the heater to follow a generally helical, or upwardly swirling, flow path. The combination of even radial spacing, an increased flow path over the heater, and it is believed, the turbulence in the fluid flow created by the presence of the wire in the flow path, all combine to increase the efficiency and volume of smoke production, other factors being constant.
The wire provides some degree of lateral position control through its physical presence in the gap and, in part, through a degree of movement d
Aronie Alan
Aronie Joel
Edwards & Angell LLP
Manus Peter J.
Paik Sang
Quikpoint, Inc.
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