CA1071279A - Extension thermostat for electric heating element control - Google Patents
Extension thermostat for electric heating element controlInfo
- Publication number
- CA1071279A CA1071279A CA264,918A CA264918A CA1071279A CA 1071279 A CA1071279 A CA 1071279A CA 264918 A CA264918 A CA 264918A CA 1071279 A CA1071279 A CA 1071279A
- Authority
- CA
- Canada
- Prior art keywords
- rod
- tube
- switch
- arm
- heating element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B1/00—Details of electric heating devices
- H05B1/02—Automatic switching arrangements specially adapted to apparatus ; Control of heating devices
- H05B1/0227—Applications
- H05B1/0252—Domestic applications
-
- A—HUMAN NECESSITIES
- A45—HAND OR TRAVELLING ARTICLES
- A45D—HAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
- A45D1/00—Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor
- A45D1/02—Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor with means for internal heating, e.g. by liquid fuel
- A45D1/04—Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor with means for internal heating, e.g. by liquid fuel by electricity
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K3/00—Tools, devices, or special appurtenances for soldering, e.g. brazing, or unsoldering, not specially adapted for particular methods
- B23K3/02—Soldering irons; Bits
- B23K3/03—Soldering irons; Bits electrically heated
- B23K3/033—Soldering irons; Bits electrically heated comprising means for controlling or selecting the temperature or power
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D23/00—Control of temperature
- G05D23/19—Control of temperature characterised by the use of electric means
- G05D23/275—Control of temperature characterised by the use of electric means with sensing element expanding, contracting, or fusing in response to changes of temperature
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H37/00—Thermally-actuated switches
- H01H37/02—Details
- H01H37/32—Thermally-sensitive members
- H01H37/46—Thermally-sensitive members actuated due to expansion or contraction of a solid
- H01H37/48—Thermally-sensitive members actuated due to expansion or contraction of a solid with extensible rigid rods or tubes
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Hair Curling (AREA)
- Control Of Resistance Heating (AREA)
- Catching Or Destruction (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
- Fats And Perfumes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An extension thermostat for controlling the energiza-tion of an electric heating element of e.g. a curling iron has a rod extending along the interior of a sensing tube which is inserted into the heating element, the rod having a lower co-efficient of thermal expansion than the heating tube. The rod is secured to the tube at one point, and the tube is secured at a different point, whereby the rod moves within the tube on ex-tension and contraction of the tube in response to temperature variations. One end of the rod engages one arm of a double-armed lever, the other of which is connected through a tempera-ture adjustment mechanism to a switch for opening and closing a current path to the heating element. By adjusting the mechan-ism, the operating temperature of the curling iron can be regulated.
An extension thermostat for controlling the energiza-tion of an electric heating element of e.g. a curling iron has a rod extending along the interior of a sensing tube which is inserted into the heating element, the rod having a lower co-efficient of thermal expansion than the heating tube. The rod is secured to the tube at one point, and the tube is secured at a different point, whereby the rod moves within the tube on ex-tension and contraction of the tube in response to temperature variations. One end of the rod engages one arm of a double-armed lever, the other of which is connected through a tempera-ture adjustment mechanism to a switch for opening and closing a current path to the heating element. By adjusting the mechan-ism, the operating temperature of the curling iron can be regulated.
Description
i~71279 The present invention relates to an extension thermo-stat for controlling the energization of an electric heating element, in particular for hair treatment apparatuses.
Thermostats are necessary in numerous technical ap-paratuses, especially in warming pans, coffee machines or heating plates.
In hair treatment apparatuses, e.g. curling irons, it is also required to be able to regulate the heating temperature.
Such curling irons normally have a heater by which heat is provided for curling hair, which is initially moistened and then treated by the hair treatment apparatus. m e heating temperature is, however, not adjustable, so that in some cases it is too high and in other cases it is too low. A particular problem arises in the temperature control of steam curling irons when it is desired to control the temperature relatively accurately within a relatively limited range of about 100C to 150C. The lower limit temperature of 100C corresponds to the vapourization temperature of water, while the upper temperature of 150C should not be exceeded, otherwise the hair will be damaged.
In U.S. Patent 3,534,392, there is disclosed a curling iron having a resistor in the form of a heater spiral functioning as a heater. This electrical resistor is provided with a thermo-stat which prevents over-heating of the resistor. The thermostat comprises a bi-metallic relay which switches on and off at predetermined temperatures. However, bi-metallic relays have the disadvantage that they are trouble-prone and operate inaccurately. Moreover, a thermostat of the above-described kind is not continuously adjustable, i.e. it switches on and off only at predetermined temperatures which cannot be altered by the person using the curling iron.
~`;
.
lO~lZ7g It is accordingly an object of the present invention to pro-vide a novel and improved extension thermostat which enables the opera-ting temperatures of a heat treatment apparatus to be readily adjusted.
According to the present invention, there is provided an extension thermostat for controlling the energization of a heating element, comprising a heat sensor, the heat sensor comprising a sensing tube and a rod received in the sensing tube; the rod having a co-efficient of thermal expansion different from that of the sensing tube; the rod and the sensing tube being in secure engage-10 ment at at least one position; and the rod or the sensing tube beingsecured to a fixed point, whereby relative movement of the rod and the sensing tube is caused by extension and contraction of the rod or ~ -the tube in response to temperature variations; switch means actua-table by the relative movement of the rod and the sensing tube; a heating element located in the vicinity of the heat sensor and hav-ing a current circuit the energization of which is controlled by the switch means; a double-armed lever having a first lever arm engaged by the heat sensor and a temperature adjustment mechanism connect-ing the second lever arm of the lever to a switch actuation member 20 forming part of the switch means.
In one advantageous embodiment of the invention, the first lever arm is shorter than the second lever arm, and the adjustment mechanism comprises a threaded member which can be screwed through the second lever arm and which is arranged below the switch actua-tion member of the switch means, the threaded member being con-nected to part of an adjustment disc and, by a spring, to the switch actuation member. In order to adjust the required end temperature of the hair treatment apparatus, the user has only to adjust the ad-justment disc to a pre-determined temperature. When the pre-set 30 temperature is reached, this can be indicated by means of a lamp.
Almost all of the operations required for effecting this take ~, .
.
. : : - :. - . .
1~7~
place automatically without the user having to undertake any further actions.
It is a particular advantage of the invention that it can be employed without difficulty in different technical apparatuses requiring heat regulation, e.g. in coffee machines or heating plates.
The invention will be more readily understood from the following description of a preferred embodiment thereof given, by way of example, with reference to the accompanying drawings, in which,-Figure 1 shows a plan view of a curling iron;
Figure 2 shows an enlarged view of an adjustment disc forming part of the curling iron of Figure l;
Figure 3 shows 'a view of the curling iron of Figure 1 rotated through 90 about its longitudinal axis;
Figure 4 shows parts of a thermostat of the curling iron of Figure l; and Figure 5 is a partial view, taken in cross-section to the curling iron of Figure 1, showing parts of the thermostat.
In Figure 1 of the drawings there is shown a curling iron which comprises basically a hand-grip 2, a curling rod 3, a steamer part 4 and a clamp 5. In the hand-grip 2, there is provided a clamp actuating device 6, a lamp 7 indicating the state of operation of the curling iron and an adjustment disc 8.
The supply of electrical energy is effected, in the illustrated curling iron 1, through a cable 9. When it is desired to curl hair, the hair is wound around the curling rod 3 with the clamp 5 raised and then, by releasing the clamp actuating device 6, the hair is pressed against the curling rod. Through the cable 9, a heater element, which is located in the curling rod 3 and which, ~07~279~
for example, can have the form of a cylindrical heater spiral, is supplied with an electrical energy and is thereby heated.
Simultaneously, a plate (not shown) located in the curling rod 3 is heated. The steamer part 4, wllich comprises essentially a water container from which a wick extends, can now be pressed against this plate. When the wick comes against the heated plate, the water vapourizes and passes through the curling rod to the hair. When the steaming process is completed, the moistened hair is dried again with the help of the heating element disposed in the curling rod.
When the hair treatment has been finished, the clamp 5 is released by pressure on the clamp actuating device 6, and the curled hair can be removed from the curling rod 3.
Figure 2 shows in greater detail the adjustment disc 8 already illustrated in Figure 1. As can be seen, the adjust-ment disc 8 has a knurled peripheral ring 10, which facilitates manual rotary adjustment of the adjustment disc 8. In addition, the adjustment disc 8 has a temperature range indicator 11 in the form of a segmental annular slot provided with symbols indicating middle, high and low temperatures. Instead of these symbols, the Celsius scale could, of course, could be directly indicated. By -rotations of the adjustment disc, it is possible to set the required final temperature.
Preferably, the hand-grip 2 is provided with a fixed mark pointing towards the temperature range indicator, and in this way easy observation of the adjusted temperature is provided.
Figure 3 shows the same curling iron 1 as Figure 1, but rotated through 90 about its longitudinal axis. In this position, holes provided in the curling rod 3 for the discharge of the steam can be very clearly seen.
Figure 4 diagrammatically illustrates the manner in which switch actuation is effected by means o~ a sensing tube 12 having an inner rod 13. The sensing tube 12 is held at a fasten-ing 16 and carries in its interior the rod 13, which has a notch 15 engaged by a nose 14 connected with the sensing tube 12.
While the notch 15 and the nose 14 are provided at the lower, i.e.
left-hand, ends of the rod 13 and the sensing tube 12, the oppo-site end of the rod 13 bears against the shorter arm of a double-armed lever 17. The longer arm of the lever 17 bears against a switch actuation plunger 20 of a micro switch 19, the conductors 21 of which extend to a heating element (not shown). If the temperature around the sensing tube 12 increases, the sensing tube 12 expands. Since, however, it is fixedly secured at one end, it can expand in only one direction, i.e. to the left as viewed in Figure 4. By this leftward movement, the rod 13 in the sensing tube 12 is likewise drawn to the left, since it is connected by the notch 15 to the sensing tube 12. Since the rod 13, however, in contrast to the sensing tube 12, is not fixedly secured at one end, it also moves its end, which bears against the lever 17, towards the left, whereby the force acting on the switch actuation plunger 20 of the microswitch 19 is reduced and the current supply is switched off. When the sensing tube 12 cools, the lever 17 pivots in the opposite direction about its pivot 18.
The arrangement of the sensing tube 12 with a high co-efficient of thermal expansion around the rod 13 with a low co-efficient of thermal expansion has particular advantages over the opposite arrangement. If the inner rod 13 had the larger co-efficient of thermal expansion and if it displaced a tube, so that the latter actuated a switch, then a time delay would occur before the switch actuation was effected. This time delay would 1071~
be caused since the outer temperature would not immediately reach the inner rod, but would firstly have to pass through the outer tube. Since the regulator shown in Figure 4 is a two-way regula-tor, i.e. only switches on or off, the temperature differences between switching on and switching off would be too large and, in extreme cases, would exceed the control range of 100C to 150C, which is important in steam curling. A temperature deviation of plus or minus 5C should in no case be exceeded.
In order to obtain a regulation which is as exact as possible, the heat transfer between the heating spiral or casing on the one hand, and the sensing tube on the other hand, must of course be sufficiently good. This is achieved by appropriate arrangement of the sensing tube on or in the heating element.
Pre-adjustment of the final temperature to be reached is not possible using only the parts shown in Figure 4, but is effected by the arrangement shown in Figure 5.
Figure 5 shows the hand-grip 2 of the curling iron 1, which hand-grip 2 contains the sensing tube 12 and the rod thirt-een. One end of the sensing tube 12 extends into a heating element in the curling rod 3, which is not shown in this figure, and in this manner is exposed to the heat of this heating element. The other end of the sensing tube 12 is fixedly secured in the fastening 16. The shorter arm of the lever 17 is engaged by the rod 13 projecting from the sensing tube 12. The longer arm of the lever 17 extends from the pivot point 18 of the lever 17 initially in a downwardly inclined direction, as viewed in Figure 5, and then has a horizontal disposition. Consequently, the shorter and longer lever arms are disposed practically perpendicu-lar to one another, which, however, is not essential to the invention but is merely particularly advantageous in the present 107127~
embodiment of the curling iron~
In the horizontal part of the longer lever arm, there is screwed a threaded bolt 25, which bears against the switch actua-tion plunger 20 of the microswitch 19. This microswitch 19 has --terminals 27, 28 and 29 to which corresponding conductors 30, 31 and 32 extend. By actuation of the switch actuation plunger 20, the conductors, which extend to the heating element, can be energized or de-energized.
The force required for actuating the switch actuation plunger 20 is provided mainly by a spring 23, which has one end secured to a fixed portion of the hand-grip 2 and which has its other end engaged in the longer arm of the lever 17. By accurate dimensioning of the spring 23, the lever 17, the sensing tube 12 and the rod 13, and by adjustment of the sensing tube 12 relative to the lever 17, an arrangment can be provided for producing an ; accurately defined final temperature of the curling rod 3.
Alteration of the final temperature can then be obtained by means of the adjustment disc 8. When the adjustment disc 8 is manually rotated, then it in turn rotates a bolt 24, which is connected to it, and thus drives a spring 22. The spring 22, in turn, rotates the threaded bolt 25 and screws inwardly or out-wardly of the longer arm of the lever 17. In this way, the spacing between the longer lever arm and the switch actuation plunger 20 is altered, which effects an earlier or later actuation of the microswitch 19 as desired.
With the arrangement shown in Figure 5, it is not the purpose of the spring 22 to provide a spring force in the vertical direction; moreover, a spring is used only since, by means of the spring, the actual displacement of the threaded bolt 25 caused by the inward or outward screwing of the threaded bolt 25 in the ~07~279 lever arm does not affect the bolt 24. Instead of the spring, any other element, e.g. vulcanized rubber concertina wall, which ful-fills the same functions could be employed.
~ loreover, the use of microswitch 19 of the type illus-trated is not absolutely essential, since any switch having a small switching path and which can be fixed on a part fixedly connected by a screw 26 to the hand-grip 2 may be employed.
It has been found that brass or aluminum are particu-lar materials for the sensing tube 12, while the rod 13 preferably comprises a nickel-iron alloy. However, other materials may be employed, provided that they differ from one another sufficiently with respect to their co-efficients of thermal expansion.
Although the above-described embodiment of the inven-tion is a curling iron, the invention is in no way restricted to curling irons, but can be employed with advantage whenever it is required to provide a variable temperature limit.
Thermostats are necessary in numerous technical ap-paratuses, especially in warming pans, coffee machines or heating plates.
In hair treatment apparatuses, e.g. curling irons, it is also required to be able to regulate the heating temperature.
Such curling irons normally have a heater by which heat is provided for curling hair, which is initially moistened and then treated by the hair treatment apparatus. m e heating temperature is, however, not adjustable, so that in some cases it is too high and in other cases it is too low. A particular problem arises in the temperature control of steam curling irons when it is desired to control the temperature relatively accurately within a relatively limited range of about 100C to 150C. The lower limit temperature of 100C corresponds to the vapourization temperature of water, while the upper temperature of 150C should not be exceeded, otherwise the hair will be damaged.
In U.S. Patent 3,534,392, there is disclosed a curling iron having a resistor in the form of a heater spiral functioning as a heater. This electrical resistor is provided with a thermo-stat which prevents over-heating of the resistor. The thermostat comprises a bi-metallic relay which switches on and off at predetermined temperatures. However, bi-metallic relays have the disadvantage that they are trouble-prone and operate inaccurately. Moreover, a thermostat of the above-described kind is not continuously adjustable, i.e. it switches on and off only at predetermined temperatures which cannot be altered by the person using the curling iron.
~`;
.
lO~lZ7g It is accordingly an object of the present invention to pro-vide a novel and improved extension thermostat which enables the opera-ting temperatures of a heat treatment apparatus to be readily adjusted.
According to the present invention, there is provided an extension thermostat for controlling the energization of a heating element, comprising a heat sensor, the heat sensor comprising a sensing tube and a rod received in the sensing tube; the rod having a co-efficient of thermal expansion different from that of the sensing tube; the rod and the sensing tube being in secure engage-10 ment at at least one position; and the rod or the sensing tube beingsecured to a fixed point, whereby relative movement of the rod and the sensing tube is caused by extension and contraction of the rod or ~ -the tube in response to temperature variations; switch means actua-table by the relative movement of the rod and the sensing tube; a heating element located in the vicinity of the heat sensor and hav-ing a current circuit the energization of which is controlled by the switch means; a double-armed lever having a first lever arm engaged by the heat sensor and a temperature adjustment mechanism connect-ing the second lever arm of the lever to a switch actuation member 20 forming part of the switch means.
In one advantageous embodiment of the invention, the first lever arm is shorter than the second lever arm, and the adjustment mechanism comprises a threaded member which can be screwed through the second lever arm and which is arranged below the switch actua-tion member of the switch means, the threaded member being con-nected to part of an adjustment disc and, by a spring, to the switch actuation member. In order to adjust the required end temperature of the hair treatment apparatus, the user has only to adjust the ad-justment disc to a pre-determined temperature. When the pre-set 30 temperature is reached, this can be indicated by means of a lamp.
Almost all of the operations required for effecting this take ~, .
.
. : : - :. - . .
1~7~
place automatically without the user having to undertake any further actions.
It is a particular advantage of the invention that it can be employed without difficulty in different technical apparatuses requiring heat regulation, e.g. in coffee machines or heating plates.
The invention will be more readily understood from the following description of a preferred embodiment thereof given, by way of example, with reference to the accompanying drawings, in which,-Figure 1 shows a plan view of a curling iron;
Figure 2 shows an enlarged view of an adjustment disc forming part of the curling iron of Figure l;
Figure 3 shows 'a view of the curling iron of Figure 1 rotated through 90 about its longitudinal axis;
Figure 4 shows parts of a thermostat of the curling iron of Figure l; and Figure 5 is a partial view, taken in cross-section to the curling iron of Figure 1, showing parts of the thermostat.
In Figure 1 of the drawings there is shown a curling iron which comprises basically a hand-grip 2, a curling rod 3, a steamer part 4 and a clamp 5. In the hand-grip 2, there is provided a clamp actuating device 6, a lamp 7 indicating the state of operation of the curling iron and an adjustment disc 8.
The supply of electrical energy is effected, in the illustrated curling iron 1, through a cable 9. When it is desired to curl hair, the hair is wound around the curling rod 3 with the clamp 5 raised and then, by releasing the clamp actuating device 6, the hair is pressed against the curling rod. Through the cable 9, a heater element, which is located in the curling rod 3 and which, ~07~279~
for example, can have the form of a cylindrical heater spiral, is supplied with an electrical energy and is thereby heated.
Simultaneously, a plate (not shown) located in the curling rod 3 is heated. The steamer part 4, wllich comprises essentially a water container from which a wick extends, can now be pressed against this plate. When the wick comes against the heated plate, the water vapourizes and passes through the curling rod to the hair. When the steaming process is completed, the moistened hair is dried again with the help of the heating element disposed in the curling rod.
When the hair treatment has been finished, the clamp 5 is released by pressure on the clamp actuating device 6, and the curled hair can be removed from the curling rod 3.
Figure 2 shows in greater detail the adjustment disc 8 already illustrated in Figure 1. As can be seen, the adjust-ment disc 8 has a knurled peripheral ring 10, which facilitates manual rotary adjustment of the adjustment disc 8. In addition, the adjustment disc 8 has a temperature range indicator 11 in the form of a segmental annular slot provided with symbols indicating middle, high and low temperatures. Instead of these symbols, the Celsius scale could, of course, could be directly indicated. By -rotations of the adjustment disc, it is possible to set the required final temperature.
Preferably, the hand-grip 2 is provided with a fixed mark pointing towards the temperature range indicator, and in this way easy observation of the adjusted temperature is provided.
Figure 3 shows the same curling iron 1 as Figure 1, but rotated through 90 about its longitudinal axis. In this position, holes provided in the curling rod 3 for the discharge of the steam can be very clearly seen.
Figure 4 diagrammatically illustrates the manner in which switch actuation is effected by means o~ a sensing tube 12 having an inner rod 13. The sensing tube 12 is held at a fasten-ing 16 and carries in its interior the rod 13, which has a notch 15 engaged by a nose 14 connected with the sensing tube 12.
While the notch 15 and the nose 14 are provided at the lower, i.e.
left-hand, ends of the rod 13 and the sensing tube 12, the oppo-site end of the rod 13 bears against the shorter arm of a double-armed lever 17. The longer arm of the lever 17 bears against a switch actuation plunger 20 of a micro switch 19, the conductors 21 of which extend to a heating element (not shown). If the temperature around the sensing tube 12 increases, the sensing tube 12 expands. Since, however, it is fixedly secured at one end, it can expand in only one direction, i.e. to the left as viewed in Figure 4. By this leftward movement, the rod 13 in the sensing tube 12 is likewise drawn to the left, since it is connected by the notch 15 to the sensing tube 12. Since the rod 13, however, in contrast to the sensing tube 12, is not fixedly secured at one end, it also moves its end, which bears against the lever 17, towards the left, whereby the force acting on the switch actuation plunger 20 of the microswitch 19 is reduced and the current supply is switched off. When the sensing tube 12 cools, the lever 17 pivots in the opposite direction about its pivot 18.
The arrangement of the sensing tube 12 with a high co-efficient of thermal expansion around the rod 13 with a low co-efficient of thermal expansion has particular advantages over the opposite arrangement. If the inner rod 13 had the larger co-efficient of thermal expansion and if it displaced a tube, so that the latter actuated a switch, then a time delay would occur before the switch actuation was effected. This time delay would 1071~
be caused since the outer temperature would not immediately reach the inner rod, but would firstly have to pass through the outer tube. Since the regulator shown in Figure 4 is a two-way regula-tor, i.e. only switches on or off, the temperature differences between switching on and switching off would be too large and, in extreme cases, would exceed the control range of 100C to 150C, which is important in steam curling. A temperature deviation of plus or minus 5C should in no case be exceeded.
In order to obtain a regulation which is as exact as possible, the heat transfer between the heating spiral or casing on the one hand, and the sensing tube on the other hand, must of course be sufficiently good. This is achieved by appropriate arrangement of the sensing tube on or in the heating element.
Pre-adjustment of the final temperature to be reached is not possible using only the parts shown in Figure 4, but is effected by the arrangement shown in Figure 5.
Figure 5 shows the hand-grip 2 of the curling iron 1, which hand-grip 2 contains the sensing tube 12 and the rod thirt-een. One end of the sensing tube 12 extends into a heating element in the curling rod 3, which is not shown in this figure, and in this manner is exposed to the heat of this heating element. The other end of the sensing tube 12 is fixedly secured in the fastening 16. The shorter arm of the lever 17 is engaged by the rod 13 projecting from the sensing tube 12. The longer arm of the lever 17 extends from the pivot point 18 of the lever 17 initially in a downwardly inclined direction, as viewed in Figure 5, and then has a horizontal disposition. Consequently, the shorter and longer lever arms are disposed practically perpendicu-lar to one another, which, however, is not essential to the invention but is merely particularly advantageous in the present 107127~
embodiment of the curling iron~
In the horizontal part of the longer lever arm, there is screwed a threaded bolt 25, which bears against the switch actua-tion plunger 20 of the microswitch 19. This microswitch 19 has --terminals 27, 28 and 29 to which corresponding conductors 30, 31 and 32 extend. By actuation of the switch actuation plunger 20, the conductors, which extend to the heating element, can be energized or de-energized.
The force required for actuating the switch actuation plunger 20 is provided mainly by a spring 23, which has one end secured to a fixed portion of the hand-grip 2 and which has its other end engaged in the longer arm of the lever 17. By accurate dimensioning of the spring 23, the lever 17, the sensing tube 12 and the rod 13, and by adjustment of the sensing tube 12 relative to the lever 17, an arrangment can be provided for producing an ; accurately defined final temperature of the curling rod 3.
Alteration of the final temperature can then be obtained by means of the adjustment disc 8. When the adjustment disc 8 is manually rotated, then it in turn rotates a bolt 24, which is connected to it, and thus drives a spring 22. The spring 22, in turn, rotates the threaded bolt 25 and screws inwardly or out-wardly of the longer arm of the lever 17. In this way, the spacing between the longer lever arm and the switch actuation plunger 20 is altered, which effects an earlier or later actuation of the microswitch 19 as desired.
With the arrangement shown in Figure 5, it is not the purpose of the spring 22 to provide a spring force in the vertical direction; moreover, a spring is used only since, by means of the spring, the actual displacement of the threaded bolt 25 caused by the inward or outward screwing of the threaded bolt 25 in the ~07~279 lever arm does not affect the bolt 24. Instead of the spring, any other element, e.g. vulcanized rubber concertina wall, which ful-fills the same functions could be employed.
~ loreover, the use of microswitch 19 of the type illus-trated is not absolutely essential, since any switch having a small switching path and which can be fixed on a part fixedly connected by a screw 26 to the hand-grip 2 may be employed.
It has been found that brass or aluminum are particu-lar materials for the sensing tube 12, while the rod 13 preferably comprises a nickel-iron alloy. However, other materials may be employed, provided that they differ from one another sufficiently with respect to their co-efficients of thermal expansion.
Although the above-described embodiment of the inven-tion is a curling iron, the invention is in no way restricted to curling irons, but can be employed with advantage whenever it is required to provide a variable temperature limit.
Claims (10)
1. Hair treatment apparatus comprising:
a tubular member about which hair to be curled is wound;
a heating element for heating said member, and;
an expansion thermostat for controlling the energisation of said heating element;
the thermostat comprising:
a sensor tube, and;
a rod located within the tube and firmly attached thereto at one point, the tube and rod being located within said tubular member and having different coefficients of ther-mal expansion so that the rod moves longitudinally relative to the sensor tube remote from said one point due to variations in temperature of the tubular member, the thermostat further comprising a switch for controlling the energisation of said heating element and operable in response to one arm of a lever whose other arm is adjustably moved in response to said rela-tive movement.
a tubular member about which hair to be curled is wound;
a heating element for heating said member, and;
an expansion thermostat for controlling the energisation of said heating element;
the thermostat comprising:
a sensor tube, and;
a rod located within the tube and firmly attached thereto at one point, the tube and rod being located within said tubular member and having different coefficients of ther-mal expansion so that the rod moves longitudinally relative to the sensor tube remote from said one point due to variations in temperature of the tubular member, the thermostat further comprising a switch for controlling the energisation of said heating element and operable in response to one arm of a lever whose other arm is adjustably moved in response to said rela-tive movement.
2. Apparatus according to claim 1, wherein the sen-sor tube is made of brass, aluminium or another metal or metal alloy.
3. Apparatus according to claim 1, wherein the rod is made of an iron-nickel alloy.
4. Apparatus according to any of claims 1, 2 or 3, wherein the switch is a micro-switch.
5. Apparatus according to claim 1, wherein said other arm of said lever is shorter than said one arm, said one arm being connected to a spring.
6. Apparatus according to claim 5, wherein the spring produces the necessary switching force for operation of the switch.
7. Apparatus according to claim 5, wherein the longer arm of the lever features a threaded plug which can be screwed through the longer arm of the lever and which is located adja-cent the operating member of the switch and is engageable with said member to operate the switch, and wherein a connection exists between the threaded plug and a rotatable regulator element, whereby rotation of the regulator element rotates the threaded plug to vary its distance from the operating member, thereby to vary the temperature at which the switch is operated.
8. Apparatus according to claim 7, wherein the connection between the screwed plug and the regulator element includes means to accommodate movement of the screwed plug rela-tively to the regulator element.
9. Apparatus according to claim 8, wherein said means comprise a sinuous spring.
10. Apparatus as claimed in any one of claims 1, 2 or 3, wherein the heating element is a cylinder-shaped cartridge, or a helical wire element in which a part of the sensor tube, together with the rod is disposed.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19762603280 DE2603280A1 (en) | 1976-01-29 | 1976-01-29 | HEATING CONTROL |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071279A true CA1071279A (en) | 1980-02-05 |
Family
ID=5968518
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA264,918A Expired CA1071279A (en) | 1976-01-29 | 1976-11-04 | Extension thermostat for electric heating element control |
Country Status (15)
| Country | Link |
|---|---|
| JP (1) | JPS5295341A (en) |
| BE (1) | BE850708A (en) |
| BR (1) | BR7608837A (en) |
| CA (1) | CA1071279A (en) |
| CH (1) | CH614362A5 (en) |
| DE (1) | DE2603280A1 (en) |
| DK (1) | DK588576A (en) |
| ES (1) | ES455442A1 (en) |
| FI (1) | FI763470A (en) |
| FR (1) | FR2340015A1 (en) |
| GB (1) | GB1517600A (en) |
| IT (1) | IT1143631B (en) |
| NL (1) | NL7613366A (en) |
| NO (1) | NO145067C (en) |
| SE (1) | SE415139B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DK153736C (en) * | 1979-12-05 | 1989-01-23 | Braun Ag | HAIR CURLING APPARATUS |
| DE2948857C2 (en) * | 1979-12-05 | 1982-08-19 | Braun Ag, 6000 Frankfurt | Hair curler |
| US4327752A (en) * | 1979-12-05 | 1982-05-04 | Braun, Aktiengesellschaft | Rotary ignition system for a catalytically heated curling device |
| DE202006000670U1 (en) * | 2006-01-18 | 2007-05-31 | Wik Far East Ltd. | Resistance heating element for a hair styling device and hair styling device equipped therewith |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1438308A (en) * | 1920-03-27 | 1922-12-12 | George F Hunter | Electric-circuit breaker |
| FR884485A (en) * | 1942-07-25 | 1943-08-18 | Snap-action thermostat | |
| US2498988A (en) * | 1946-08-02 | 1950-02-28 | William C Eden | Thermostatic control mechanism |
| US2815415A (en) * | 1956-05-29 | 1957-12-03 | James E Axeman | Movement responsive control apparatus, especially for temperature response |
| FR1595373A (en) * | 1968-02-01 | 1970-06-08 | ||
| FR2123634A5 (en) * | 1971-01-26 | 1972-09-15 | Primpied Jacques | |
| DE2141707A1 (en) * | 1971-08-20 | 1973-02-22 | Tuerk & Hillinger Kg | ELECTRIC HEATER CARTRIDGE WITH TEMPERATURE LIMITER |
| US3745140A (en) * | 1971-09-22 | 1973-07-10 | Allied Chem | Shapable fiber-reinforced novaculitefilled low molecular weight polyethylene terephthalate |
-
1976
- 1976-01-29 DE DE19762603280 patent/DE2603280A1/en not_active Withdrawn
- 1976-10-26 SE SE7611866A patent/SE415139B/en unknown
- 1976-11-04 CA CA264,918A patent/CA1071279A/en not_active Expired
- 1976-11-19 NO NO763977A patent/NO145067C/en unknown
- 1976-11-30 CH CH1506276A patent/CH614362A5/en not_active IP Right Cessation
- 1976-12-01 NL NL7613366A patent/NL7613366A/en not_active Application Discontinuation
- 1976-12-02 FI FI763470A patent/FI763470A/fi not_active Application Discontinuation
- 1976-12-14 GB GB52142/76A patent/GB1517600A/en not_active Expired
- 1976-12-30 BR BR7608837A patent/BR7608837A/en unknown
- 1976-12-30 DK DK588576A patent/DK588576A/en unknown
-
1977
- 1977-01-21 IT IT19532/77A patent/IT1143631B/en active
- 1977-01-21 FR FR7701711A patent/FR2340015A1/en not_active Withdrawn
- 1977-01-25 BE BE2055621A patent/BE850708A/en unknown
- 1977-01-28 JP JP861677A patent/JPS5295341A/en active Pending
- 1977-01-28 ES ES455442A patent/ES455442A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| IT1143631B (en) | 1986-10-22 |
| SE7611866L (en) | 1977-07-30 |
| FR2340015A1 (en) | 1977-08-26 |
| BE850708A (en) | 1977-05-16 |
| NO763977L (en) | 1977-08-01 |
| GB1517600A (en) | 1978-07-12 |
| BR7608837A (en) | 1977-10-25 |
| JPS5295341A (en) | 1977-08-10 |
| DK588576A (en) | 1977-07-30 |
| NO145067C (en) | 1982-01-04 |
| ES455442A1 (en) | 1978-04-16 |
| FI763470A (en) | 1977-07-30 |
| SE415139B (en) | 1980-09-15 |
| NL7613366A (en) | 1977-08-02 |
| DE2603280A1 (en) | 1977-08-11 |
| NO145067B (en) | 1981-09-21 |
| CH614362A5 (en) | 1979-11-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |