Portable curling iron

A portable curling iron having a barrel to be heated, includes first and second burners which heat the barrel; a fuel supply cartridge which supplies fuel to the first and second burners, the cartridge including a fuel delivery valve which controls the flow of fuel from the cartridge; a plunger which applies a force to the valve in response to user actuation, to start the flow of fuel from the cartridge; a regulator assembly including a diaphragm which applies a reverse force to the plunger when the gas pressure exceeds a predetermined pressure, to maintain a substantially constant flow rate of fuel to the first and second burners; a valve stem through which the fuel travels from the cartridge to the second burner; a bimetallic element for applying a force to the valve stem to permit the fuel to pass to the second burner when the temperature is less than a predetermined start-up temperature and for removing such force when the predetermined start-up temperature is attained; and a spring which applies a reverse force to the valve stem to prevent the fuel to pass to the second burner when the predetermined start-up temperature is attained, so as to achieve fast heat up of the barrel without fuel waste.

BACKGROUND OF THE INVENTION 
This invention relates generally to portable heating appliances and, more 
particularly, is directed to a novel portable curling iron. 
A curling iron curls hair by wrapping the hair, tress by tress, around a 
heated barrel, holding the wrapped tress for a period of time and then 
unwrapping the tress. The length of time the hair is held wrapped around 
the barrel, the temperature, the diameter of the barrel and the hair's 
characteristics largely determine the tightness of the curl. 
Some curling irons are portable. These heat the barrel by an electrical 
heat source or a portable fuel source. Electrical portable curling irons 
are relatively impractical, but catalytic gas powered curling irons are 
widely employed. The catalytic converter thereof are powered by butane or 
similar type gases which may take the form of replaceable or refillable 
cartridges. Such portable curling irons are widely used, and may be 
conveniently used almost anywhere. 
Catalytic burners for portable curling irons suffer from several 
disadvantages. First, they are slow to heat and expensive to manufacture, 
which are clearly undesirable. Additionally, if the temperature runs too 
high, the platinum catalyst sinters, reducing surface area, which reduces 
life. 
Still further, catalytic converters can suffer from "hot spots" which can 
render them dangerous. 
OBJECTS AND SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide a system for 
portable devices requiring a heated portion which eliminates the 
above-mentioned problems. 
It is another object of this invention to provide such a system which may 
be advantageously used in curling irons. 
It is still another object of this invention to provide such a system which 
may be used with portable irons, portable hot trays, hair roller setters, 
portable bottle warmers as well as many other portable products. 
It is yet another object of this invention to provide such a system which 
is readily adaptable to portable use, yet which permits rapid heating of 
the element to be heated. 
It is a further object of this invention to provide such a system in which 
the operating temperature is maintained substantially constant. 
It is a still further object of this invention to provide such a system in 
which a source of fuel is employed which may be rechargeable or 
refillable. 
It is a yet further object of this invention to provide such a system in 
which the element to be heated rapidly achieves the desired temperature, 
yet in which the temperature is maintained with decreased fuel 
consumption. 
It is another object of this invention to provide such a system which is 
safe to use. 
In accordance with the principles of this invention, the above objects are 
accomplished by providing a fuel delivery and ignition system for a 
portable heating appliance which quickly heats the working surface and 
then reduces the fuel flow when the desired temperature is reached. 
Additionally, a regulator is provided which controls the fuel rate to 
maintain a substantially constant temperature of the working surface. 
Specifically, a piezoelectric ignitor is provided to initially ignite the 
two burners. After the desired surface temperature is reached, one of the 
burners is turned off, and the remaining burner continues to operate and 
maintain the surface temperature substantially constant.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring to the drawings in detail, a portable curling iron 10 according 
to the present invention includes a handle 12 which may serve as a cover 
over a barrel 14 thereof which is to be heated. Handle 12 is shown in 
FIGS. 1 and 2 in its operative condition, that is, removed from barrel 14. 
As shown in FIG. 2, when handle 12 is so positioned, it slides a switch 
button 16 to the right in FIG. 2 to the position shown. Switch button 16, 
as will be described in greater detail hereinafter, functions as an ON/OFF 
switch, to start the flow of a gas fuel, such as butane, from a fuel 
cartridge 18. Then, an ignitor push button 20 (FIG. 1) is depressed by the 
user to control a piezoelectric ignitor which ignites the butane to heat 
barrel 14. 
As discussed, curling iron 10 is gas fueled, the gas being carried in fuel 
cartridge 18 and transported to the delivery end by a sintered plastic 
wick 22. Cartridge 18 may be refillable through a fill valve 24, or 
replaceable, as desired. As shown in FIG. 2, cartridge 18 includes a 
charcoal filter material 26 and a foam lining 28, as is conventional. 
In addition, cartridge 18 includes a fuel delivery valve 30 at the end 
opposite fill valve 24. Specifically, fuel delivery valve 30 is assembled 
in a molded well 32 in the end of cartridge 18 which attaches to curling 
iron 10. Molded well 32 includes a smooth first section 34 having a first 
diameter, and a second section 36 having a second, larger diameter which 
is threaded as at 38. 
Fuel delivery valve 30 includes an aluminum wick holder 40 press fit into 
the inner end of first section 34 of molded well 32. One end of sintered 
plastic wick 22 is pressed into wick holder 40 and the opposite end of 
wick 22 extends to near the bottom of cartridge 18 at the opposite end 
thereof. A cylindrical brass part 44 is positioned within well 32. 
Cylindrical brass part 44 includes a first section 46 adjacent wick holder 
40 and having a diameter substantially equal to that of smooth first 
section 34, and a second shaft section 48 of a smaller diameter. A tube of 
compressible foam 50, which forms an adjustable flow restrictor, has a 
central opening and is located on second shaft section 48 of brass part 
44, where the latter centers foam tube 50 within well 32. As will be 
appreciated from the discussion hereinafter, the degree of compression of 
foam tube 50 changes the flow rate of gas therethrough. 
After the above has been assembled in well 32, the portion of fuel delivery 
valve 30 which compresses foam tube 50 is assembled in well 32. 
Specifically, a tubular brass spacer 52 having an outer diameter 
substantially equal to that of smooth first section 34 of well 32 is 
slidably fit therein. Spacer 52 includes an end face 54 which abuts 
against foam tube 50 to compress the same when a force is applied thereto. 
A circular groove 56 is formed in the outer surface of spacer 52 in which 
an O-ring 58 is inserted for preventing any leakage between the inner wall 
of well 32 and the outer surface of spacer 52. Spacer 52 includes a 
central bore 60 of substantially equal diameter to second shaft section 48 
of cylindrical brass part 44 and which slidably fits thereover. Central 
bore 60 has an enlarged diameter, as at 62, at the opposite end thereof. 
A cylindrical molded plastic upper valve housing 64 is provided with 
external threads which screw threadedly mate with threads 38 of second 
section 36 of well 32 for securing housing 64 therein. Housing 64 includes 
a first central, cylindrical recess 66 at one end which surrounds the 
outer surface of spacer 52, and a second central, cylindrical recess 68 at 
the opposite end, recesses 66 and 68 being separated by a wall 70 having a 
central aperture 72 therein. A stem 74 is slidably fit within aperture 72 
and includes an enlarged head 76 on the end facing into cartridge 18, 
enlarged head 76 having an outer diameter substantially equal to that of 
enlarged diameter section 62 of central bore 60, but slidably fit therein. 
Thus, stem 74 is shaped like a tiny common nail, but with no sharp point. 
An annular rubber seal 78 is fit on stem 74 in abutment with enlarged head 
76. The opposite end of stem 74 which extends to the opposite side of wall 
70, is press fit into a plastic cap 80 which is slidably positioned within 
second cylindrical recess 68, plastic cap 80 being outwardly biased by a 
coil spring 82 also positioned within second cylindrical recess 68. 
In operation, when no inwardly directed force is applied to plastic cap 80, 
coil spring 82 outwardly biases plastic cap 80, thereby causing annular 
rubber seal 78 to be biased to the right of FIG. 2 in contact with and 
sandwiched between enlarged head 76 and wall 70, to maintain annular 
rubber seal 78 is compression so as to prevent the flow of any gas from 
cartridge 18. As will be explained hereinafter, this occurs when cartridge 
18 is not assembled with curling iron 10. 
When an inwardly directed force is applied to plastic cap 80, the latter 
moves to the left of FIG. 2 to the position shown, compressing coil spring 
82 and moving stem 74, enlarged head 76 and annular rubber seal 78 out of 
the sealing position, whereby gas can flow out of cartridge 18. The amount 
of gas flow will depend on the extent that foam tube 50 is compressed. It 
will be noted that, since housing 64 is screw threadedly received within 
well 32, the amount of leftward travel of stem 74 and enlarged head 76, 
and therefore the extent of compression of foam tube 50, will vary 
depending on the distance that housing 64 is screw threaded into well 32. 
Housing 64 is shown in FIG. 2 screw threaded to its maximum extent. The 
gas flow rate is preferably set at the factory and is not consumer 
adjustable. 
As shown, cartridge 18 is secured to a sliding adapter 84 of curling iron 
10 through screw threads 86 and is sealed with an O-ring 88 in a 
conventional manner. Sliding adaptor 84 includes an outer cylindrical 
section 90 which is slidably keyed within the proximal end of the housing 
92 of curling iron 10 by at least one key element 94. Outer cylindrical 
section 90 is secured to switch button 16. Specifically, switch button 16 
includes a switch knob pin 96 which extends through an elongated slot 98 
in housing 92. Switch button 16 is also formed with a forward extension 
100 having a recess 102 facing housing 92 and in which a switch spring 104 
is placed to normally bias switch button 16 to the left of FIG. 2. 
Accordingly, when handle 12 is inserted over the proximal end of curling 
iorn 10, it moves switch button 16 to the right of FIG. 2 to the position 
shown. As a result, cartridge 18 is also moved to the right of FIG. 2 and, 
as will be described hereinafter, gas flow is started. When handle 12 is 
removed and placed over barrel 14 to function as a cover, switch spring 
104 moves button 16 to the left of FIG. 2, thereby also moving cartridge 
18 to the left, to stop the flow of gas. 
Specifically, when cartridge 18 is moved to the right of FIG. 2, as shown, 
a plunger 106 hits against plastic cap 80 to move stem 74 and annular 
rubber seal 78 out of the aforementioned sealing arrangement to permit the 
flow of gas. When cartridge 18 is moved to the left of FIG. 2, plunger 106 
no longer applies a depressing force to plastic cap 80. As a result, coil 
spring 82 biases plastic cap 80, stem 74, enlarged head 76 and annular 
rubber seal 78 to the right of FIG. 2 in the aforementioned sealing 
arrangement to prevent any flow of gas from cartridge 18. 
Plunger 106 is slidably received within a regulator housing 108 of a 
regulator assembly 110 which, in turn, is slidably received within a 
central cylindrical section 112 of sliding adapter 84. An O-ring 114 
provides a sliding seal between a first section 108a of regulator housing 
108 and cylindrical section 112. Thus, gas can only flow from cartridge 18 
through a gap 116 provided between plunger 106 and first section 108a of 
regulator housing 108. 
The purpose of regulator assembly 110 is to provide vaporized fuel at 
constant pressure independent of ambient temperature, fuel consumption 
rate, orientation, brand of fuel and fuel level. Thus, a known amount of 
heat is produced at all times, corresponding to fuel consumption. 
Therefore, temperature regulation is not necessary to maintain barrel 
temperature during use and because of this, curling iron 10 according to 
the present invention is easier to assemble and adjust then prior butane 
curling irons. 
As shown in FIG. 2, first section 108a of regulator housing 108 includes a 
radially directed section 108b at the end thereof which extends from 
cylindrical section 112. Radially directed section 108b is connected to a 
second section 108c of regulator housing 108 which, in turn, is connected 
to a third section 108d thereof. The latter section 108d is connected to 
still a fourth section 108e of regulator housing 108. Of course, all of 
the sections of regulator housing 108 can be constructed in a one piece 
molding operation. Radially directed section 108b and second, third and 
fourth sections 108c, 108d and 108e, respectively, define a gas flow 
chamber 118 through which gas flows from gap 116 between first section 
108a of regulator housing 108 and plunger 106. 
Regulator assembly 110 further includes an inner assembly 120 within 
chamber 118 and which defines a central bore 122 which houses a coil 
spring 124. An adjusting screw 126 is screw threadedly received within 
central bore 122, against which one end of coil spring 124 abuts. A 
plunger stopper 128 is secured to one end of plunger 106, and includes a 
central boss 130 at the opposite end thereof. The opposite end of coil 
spring 124 surrounds and is centered by boss 130 and abuts against the 
respective end face of plunger stopper 128. Thus, coil spring 124 pushes 
on plunger 106, biasing it in the direction of cartridge 18 into abutment 
with plastic cap 80 of fuel delivery valve 30 when cartridge 18 is secured 
to curling iron 10. Butane gas therefore flows from cartridge 18, through 
gap 116 to chamber 118. 
A rubber diaphragm 132 is secured to inner assembly 120 and to plunger 
stopper 128. When the pressure of the fuel entering chamber 118 becomes 
too great, rubber diaphragm 132 is biased to the right of FIG. 2 against 
the force of coil spring 124, to move plunger 106 away from fuel delivery 
valve 30, whereby coil spring 82 of fuel delivery valve 30 causes it to 
close, halting the flow of gas. Once the gas pressure is reduced by 
burning the fuel, coil spring 124 moves rubber diaphragm 132 and plunger 
106 to the left of FIG. 2 to the position shown, to once again open fuel 
delivery valve 30. This cycle continues and maintains a constant pressure 
on the outlet side of regulator assembly 110 as long as switch 16 remains 
in the ON position. It will be appreciated that, turning adjusting screw 
126, alters the compression of coil spring 124, thus adjusting the gas 
flow pressure. 
Regulator housing 108 and inner assembly 120 define two narrow channels 134 
and 136 therebetween through which gas from chamber 118 escapes, each 
channel leading toward a respective orifice-venturi-burner assembly. 
Specifically, channel 134 leads to a valve stem 138 positioned within a 
recess defined between fourth section 108e of regulator housing 108 and 
inner assembly 120. An O-ring 140 surrounds valve stem 138 at mid-length 
to provide a gas tight seal. Valve stem 138 includes a central bore which 
defines a gas flow orifice 142 in fluid communication with channel 134. 
In like manner, a valve stem 144 is positioned within a recess defined 
between fourth section 108e of regulator housing 108 and inner assembly 
120, diametrically opposite valve stem 138. An O-ring 146 surrounds valve 
stem 144 at mid-length to provide a gas tight seal. In addition, valve 
stem 144 includes a central bore which defines a gas flow orifice 148 in 
fluid communication with channel 136. An annular, resilient valve pad 150 
is positioned at the end of valve stem 144 between channel 136 and orifice 
148. As will be appreciated from the description which follows, O-ring 146 
acts as the fulcrum of a lever, whereby valve stem 144 can rotate or rock 
thereabout to make or break a seal between channel 136 and orifice 148, by 
means of valve pad 150. Thus, when valve stem 144 is axially in line with 
barrel 14, there is not gas seal, and butane vapors flow from channel 136, 
through the central aperture of valve pad 150 to orifice 148. On the other 
hand, when valve steam 144 is tilted or rotated about O-ring 146, the 
central aperture of valve pad 150 is out of line with channel 136 and 
orifice 148, so that a seal is provided which blocks the passage of gas to 
orifice 148. 
The butane vapor from orifice 142 leads to a main burner 152, while the 
butane vapor from orifice 148 leads to a fast heat up burner 154. The 
burners differ in purpose, and each will be discussed beginning with main 
burner 152. 
The purpose of main burner 152 is to provide enough heat to maintain barrel 
14 at a desired temperature during use. After the butane vapor leaves 
orifice 142, it passes through a venturi tube 156, where air supplied from 
an annular chamber 158 is entrained to make a combustible mixture. Orifice 
142 is of sufficient size to increase the velocity of the butane vapor so 
that the correct amount of air for efficient burning will be entrained in 
venturi tube 156. The size of the orifice determines how much fuel enters 
each burner at a given pressure. The amount of fuel determines the heat up 
rate and equilibrium temperature attained. The air-butane vapor mixture 
then travels down a stainless stell tube 160 to the opposite end thereof 
where ignition and combustion occur. There, the fuel is ignited by an 
electric spark when the ignition push button 20 is pressed, and burns as 
long as ON/OFF switch button 16 is ON. 
The purpose of the fast heat up burner 154 is to reduce the time require to 
heat barrel 14 from ambient to working temperature. It differs from main 
burner 152 by virtue of a thermostatically controlled valve assembly 162 
which allows fuel to flow until barrel 14 reaches a predetermined 
temperature at which point a bimetallic element 164 thereof, secured to 
barrel 14 and to valve stem 144, deflects, and a spring 166 secured to 
fourth section 108e of regulator housing 108 and valve stem 144, pivots 
valve stem 144 about O-ring 146, whereby valve pad 150 provides a seal to 
prevent fuel flow through orifice 148 of valve stem 144. When barrel 14 is 
not at the predetermined temperature, bimetallic element 164 applies a 
force to valve stem 144, normal to its axis and against the force of 
spring 166, to maintain orifice 148 of valve stem 144 in its open 
condition, whereby butane vapor enters orifice 148 and then travels 
through a venturi tube 168 where it is entrained with air from annular 
chamber 158. As with orifice 142, orifice 148 is of sufficient size to 
increase the velocity of the butane vapor so that the correct amount of 
air for efficient burning will be entrained in venturi tube 168. The 
air-fuel mixture from venturi rube 168 travels down a stainless steel tube 
170 to the opposite end thereof where ignition and combustion occur. The 
heat produced by fast heat up burner 154 approximately doubles the heat 
output of curling iron 10. Of course, with oridice 148 closed by 
thermostatically controlled valve assembly 162, there is no combustion and 
therefore no heat. 
Therefore, the burner system consists of two parallel paths, each with the 
same capacity, but one being controlled by regulator assembly 110 and 
bimetallic element 164 and the other being controlled by regulator 
assembly 110 alone. Each path terminates in a stainless steel tube 160 or 
170 having an open end where the air-gas mixture is ignited and burned. 
Ignition is accomplished by an electric spark traveling from electrodes 172 
and 174 to the ends of stainless steel tubes 160 and 170, where combustion 
takes place, as shown in FIG. 1. Specifically, electrodes 172 and 174 are 
encased partially in ceramic tubes 176 and 178, respectively, with the 
ends thereof being exposed at the ends of stainless steel tubes 160 and 
170, as shown. The opposite ends of electrodes 172 and 174 extend into 
electrical contact with a piezoelectric crystal 180 which generates a 
spark when struck by a spring loaded hammer 182 when ignition push button 
20 is pressed. Ignition push button 20 is mounted between cartridge 18 and 
regulator assembly 110, measured in the lengthwise direction of curling 
iron 10, so that ignition push button 20 is next to ON/OFF switch button 
16. 
Thus, to operate curling iron 10, handle 12 is removed from barrel 14 and 
positioned over cartridge 18, where it biases switch button 16 to the 
right of FIG. 2, to turn ON the flow of butane gas. Then, ignition push 
button 20 is pressed once or twice to ignite the gas-air mixture at the 
end of stainless steel tubes 160 and 170. Initially, both burners 152 and 
154 are activated to quickly bring barrel 14 up to the predetermined 
temperature. Once this temperature is attained, bimetallic element 164 
deflects and spring 166 pivots valve stem 144 about O-ring 146 to prevent 
the flow of gas therethrough, and thereby shut off fast heat up burner 
154. The predetermined temperature is then maintained by regulator 
assembly 110 which is initially set for the particular desired 
temperature. As the gas flow increases too much, whereby the temperature 
also rises, the gas flow is cut off, until the pressure in chamber 118 
decreased (corresponding to the desired temperature). 
A cool tip 184 is located on the open end of barrel 14. It is molded of 
high temperature resistant plastic which is also low in thermal 
conductivity. This component provides a gripping surface, and because it 
is tubular in shape, exhaust gases escape through its screened open end. 
Further, the combustion area of curling iron 10 is surrounded by an 
expanded aluminum or wire woven screen 186. The purpose of screen 186 is 
to even out the temperature of the exhaust gases, all of which must pass 
through it. Additionally, exhaust ports (not shown) in barrel 14, which 
are conventional, have screens (not shown) of the same expanded aluminum, 
yielding a double flame arresting barrier against hot exhaust gases (even 
during ignition). Thus, curling iron 10 can be started and run in an 
explosive atmosphere of common household solvents with no danger of 
curling iron 10 starting a fire or explosion. 
Although the present invention has been described for use with a curling 
iron, clearly, the fuel supply, regulator assembly and fast heat up and 
main burners are useable in many environments in which fast heat up and 
settable barrel temperatures are desirable. The following products are a 
representative list of those which could readily use the above elements 
either alone or in combination: 
1. Curling iron 
2. Travel setter 
3. Facial hand unit 
4. Travel flat iron 
5. Travel flat iron with steam 
6. Clothers dewrinkler 
7. Contact lens sterilizer 
8. Travel hot plate 
9. Hot tray 
10. Gas match 
11. Lantern 
12. Bottle warmer 
13. Hot liquids container 
14. Hot bladed knife 
15. Solder iron 
16. Hot melt gun 
17. Travel stove 
18. Pocket hands warmer 
19. Paint stripper 
20. Heat massager 
It will also be appreciated that the regulator assembly has independent 
value and can be used without the two burner system. In like manner, the 
two burner system can be used without the regulator assembly. 
Having described a specific preferred embodiment of the invention with 
reference to the accompanying drawings, it is to be appreciated that the 
present invention is not limited to that precise embodiment and that 
various changes and modifications can be effected therein by one of 
ordinary skill in the art without departing from the spirit and scope of 
the invention as defined by the appended claims.