Portable LPG-powered hair dryer
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates in general to hair dryers, and in particular to a new and useful hair dryer which is entirely portable and self contained, heat for the hair dryer being generated by an LPG fired burner. 
     The conventional hair dryer is usable only when there is a general power source (100-220 V AC) available. Since it uses a power-consuming coil-type heat source, it is not practical to manufacture a portable hair dryer which is powered by a charger or a battery. 
     In the case of a woman in particular, she usually dresses her hair in her house or at a beauty parlor. When it is windy, or when she is exposed to rain or when on a trip for a long time or when her hair is disheveled, she has to visit a nearby beauty salon. When it is not easy to do so, she must remain with her hair unkempt or use a mousse or hair cream for dressing her hair. These instances are unpleasant and unnerving. 
     Such a problem cannot be solved by the conventional hair dryer or by using a large and heavy battery or by carrying a dryer about, for use with a power source in another house, store or location. 
     SUMMARY OF THE INVENTION 
     The present invention relates in general to a hair dryer which generates heat, not by using a general power source, but by using LPG. The invention provides a portable hair dryer which can conveniently dry hair anywhere, indoors or outdoors. 
     Accordingly, an object of the present invention is to provide a portable LPG fired hair dryer which includes a battery powered motor with fan for blowing air through the dryer. A burner which burns LPG, directs its flame against a pair of spaced apart plates which act as the heat source. The air passing through the blower body carries heat from the plates in the form of a stream of hot air for use in drying hair. 
     A further object of the present invention is to provide a completely portable yet powerful hair dryer 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 disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a sectional and partly exploded view showing the structure of the present invention; 
     FIG. 2 is a partial sectional view showing another embodiment of the present invention; and 
     FIG. 3 is a circuit diagram of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, an LPG bottle 3 is inserted into a bottle receiving chamber 2 in the main body 1 of the inventive dryer, and a bottle fixing screw 4 is threaded into the chamber behind the bottle. A nipple or conduit 16 communicates the bottle 3 with a gas-interrupting or interrupt valve 10 and a gas-adjusting valve 9 that are connected in series with each other. An air intake 8 and a burner 6 with a built-in lighter 7 are connected by a nipple or conduit 15, to the valve 9. In front of the burner 9, a twofold or double radiant plate arrangement 5, 5 is inserted. To the lower part of gas-adjusting valve 9 a valve-operating switch 11 is attached. In the upper and lower parts of the main body 1 of the dryer, a gas-interrupting thermal sensor 14 and a bimetal switch 13 are provided. A fan motor 12 with fan is placed in the rear of the body. The handle of the body 1 is furnished with a batter 17 and a charger 18. 
     Fan motor 12 comprises fan means for blowing air from the open rear end of main body 1, through the body and past plate arrangement 5, 5, where the air is heated and then passes out through the front end of the main body. The plate arrangement comprises first and second plates positioned across the front of the burner 6 and spaced from each other in the direction of air flow through the main body 1. 
     The gas bottle 3, burner 6, lighter 7, air inlet 8, gas-adjusting valve 9, gas-interrupting valve 10, operating switch 11, fan motor 12, bi-metal switch 13, gas-interrupting sensor 14, conduits 15 and 16, battery 17, and charger 18 are all well known conventional elements which are commercially available. 
     The main merit of the present invention is that it can be used without any electrical wire. It can also be used as a non-portable but cordless dryer, if desired, where electrical power is available. 
     It is economical as it does not use an expensive power source but uses cheap LPG. Examples of LPG or liquified petroleum gas are propane and butane. 
     As the dryer of the invention does not require a cord, its design is refined and it accordingly rises in commercial value. The invention solves a problem caused by being limited in use to the length of a cord as in the conventional product. Being useable even when electricity is off, the invention is very convenient. 
     Since the fan motor 12 causes air to flow to the front of the body at all times, the bottle 3 and chamber 2 are not heated, and so the invention is not dangerous but very safe. Unlike the conventional hair dryer, it is not necessary to make frequent repairs of the dryer due to snapping of the cord and there is no danger of a melting down of the main body or burning of the hair due to an overheated electrical coil. 
     In operation, the switch 11 is pushed to the front, opening the gas flow to burner 6. The gas is ignited by the lighter 7 at the same time that it is discharged and the fan motor 12 turns on. See the circuit of FIG. 3. Heat generated by ignition closes the bimetal switch 13. As shown in FIG. 3, this is required to maintain power to the fan motor 12 in the end positions of switch 11. 
     Next, the amount of gas discharged is adjusted by adjusting the position of operation switch 11 to the front or to the rear. This motion moves a ramp on switch 11 along the plunger of valve 9 to release more or less gas from bottle 3. 
     When the operation switch 11 is off, gas discharge comes to a stop but, in order to cool the remaining heat, the fan motor 12 is made to stay on until the bimetal switch 13 opens as the unit cools. 
     The gas interrupted thermal sensor 14 interrupts the gas supply through interrupt valve 10, when the battery 17 is discharged completely and the air flow stops, or when the inside of body 1 is overheated for any other reason. 
     FIG. 2 illustrates an alternate embodiment of the invention which includes means defining a gas storing chamber 19 for receiving a supply of LPG through a one-way gas injecting valve 20. One end of conduit or nipple 16 is connected to the gas chamber 19 for supplying gas to the valves and other elements of the invention which are otherwise the same as in FIG. 1. In FIG. 2, the separate gas bottle 3, bottle receiving chamber 2 and bottle fixing screw 4 are replaced by the gas chamber 19 and the injection valve 20. This forms an embodiment of the invention which can be recharged from any source of LPG and used until the gas can be replenished. 
     As described hereinabove, the present invention is convenient in use, excellent in performance and satisfactory in safety as a portable device. 
     While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.