DE9205258U1 - Temperature limit for electrically heated curlers - Google Patents

Description

UTILITY MODEL
REGISTRATION

Reference number: 008/92

Password: TEMPERATURE LIMIT FOR

ELECTRICALLY HEATED CURLER

This invention relates to electrically heated hair curlers for producing permanent waves with contact surfaces and contact pins arranged on the front side, to which a detachable current clamp can be attached, via which the current flows to the heating element of the curler and, once the operating temperature has been reached, the current flow is interrupted, thus preventing the curler from overheating.

Curling irons of the aforementioned type are known in a wide variety of designs. For example, DE-PS 28 22 989 describes a curling iron in which the resistance heating comes into direct contact with the hair and thus has a relatively high level of efficiency. The wall of the curling iron is made of a PTC material and the heating current flows through it as a whole. The use of a low-voltage source eliminates the risk of an electrical accident caused by electric current. The power source itself is integrated in a handle, so that an electrical connection from a mains connection to the curling iron is not necessary.

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The handle can be disconnected after the curling iron has heated up and connected to other curling irons that are wrapped in the hair. Due to the temperature-controlled behavior of the electrical power consumption of PTC heating elements, the power consumption is reduced when the operating temperature is reached, which provides a certain degree of control and safety when handling these curling irons. Attaching and making contact with the curling irons that are wrapped in the hair is very awkward and sometimes requires the operator to hold the curler so that the handle can be attached and made contact properly. The same problem also arises when removing the handle from the curling iron.

Other such curlers are known from US-PS 3,617,694 and US-PS 3,617,695. The curlers mentioned therein, which limit the heating current and the heating temperature by using heating elements with PTC characteristics, are, however, operated with mains voltage, so that the use effect and the flow of heat to deform the curled hair are prevented by additional insulation measures, and the risk of accidents caused by electric current cannot be ruled out.

Other types of curlers are known from DE-OS 1 557 261, which consist of sleeves that are open on one side and are designed in such a way that an electric heating element or other heat sources can be inserted into the sleeve. The curlers are designed in such a way that the heat flow from the inside of the curler to the surface takes place in such a way that there is a certain time period between the electrical heating and the heat flow to the outer surface, which is sufficient to wrap the curler into the hair without any impairment by heat.

This type of curler proposes a type of construction that is electrically heated by plugging it into a suitable power source and contains a thermostatically controlled safety device inside to prevent overheating.

When using curler parts, optimal shaping of the hair can only be achieved by wrapping the curler in the straight hair while it is cold and then moistening it with hair tonic (perm water) and heating it to a temperature of 60 - 95 ⁰ C using an external device, similar to a current clamp, and ensuring that this temperature cannot be exceeded, even if the current clamp is accidentally applied to the same curler part several times.

For example, DE-GBM 91 00 254.0 claims a hair treatment device, in particular an electrically heated hair curler made of electrically conductive material, preferably polyphenylene sulfide, on the front sides of the curler contact surfaces are arranged, which are pressed onto the contact surfaces when a current clamp is placed on the metal connection pins, thus creating a current flow to the heating element. When the current clamp is removed, the connection pin with the contact plate detaches from the contact surfaces of the curler on one side, which interrupts the power supply and the heating process. If the current clamp is placed on the contact pins several times, a further heating process is initiated, which ultimately leads to overheating and the associated risk of skin burns.

As a rule, when treating hair to create curls, around 60 curlers are wound around the head, which should be heated up in as short a time as possible.

The invention is based on the object of designing an electrically heated hair curler in such a way that, by installing a temperature limiter in the winding part of the hair curler, onto which the hair was previously wound, the temperature remains limited even when the current clamp is applied several times and thus there is no risk of overheating and injury to the scalp.

This task is solved in an electrically heated hair curler, preferably made of an electrically conductive material, by arranging a bimetal disk on one side of the contact surfaces arranged on the front, between the contact surface and the contact pin, in such a way that when the operating temperature is reached, the current flow is interrupted and thus it is not possible to exceed this operating temperature or to switch the hair curler on several times.

Further advantages of the invention emerge from the subclaims and from the description of the embodiments in conjunction with the drawings.

Show it:

the electric curler in the overall view,

a longitudinal section through a preferred embodiment of the electric hair curler,

Fig. 3 the detail section "A" with the front design of the curler and the arrangement of the temperature limiter in the closed state,

Fig. 4 shows the detail section "A" with the front design of the curler and the position of the temperature limiter in the open state.

In the hair curler (1) shown in Fig. 1, the hair curler part (2) is preferably made of polyphenylene sulfide or another electrically conductive material with the edge formations (3). A metal connection pin (5 and 6) protrudes from the center of each of the two cover caps (4 and a). The electrical voltage, which heats the hair curler (1), is applied via the connection pins (5 and 6) using the current clamp (not shown).

Fig. 2 shows a longitudinal section through the curler (1) shown in Fig. 1. The curler part (2) has a continuous central bore (7) in the middle and a metallic, electrically conductive metal layer (8) on the respective front ends of the edge formations (3), on which in turn the contact plate (9) rests on one side and a bimetallic disk (16) on the other side. The contact plate (9) is arranged in such a way that it rests permanently on the metal layer (8). The cover cap (4) is pushed over the edge formation (3) of the curler part (2) in such a way that it snaps into the annular groove (11) provided on the edge formation (3) with the formed annular spring (10) and ensures contact between the metal layer (8) and the contact plate (9).

The connecting pin (5) is guided through the central bore (12), which in turn is electrically connected to the contact plate (9).

The connection pin (6) is fixed in the central hole (14) of the cover cap (4 a) and has electrical contact with the convexly tensioned bimetal disc (16). In addition to the ring spring (17), which snaps into the ring groove (18) provided on the edge formation (3), the cover cap (4 a) has another ring spring (19), which presses the bimetal disc (16) in a ring shape onto the electrically conductive metal layer (8) of the curler part (2).

Fig. 3 shows the front side of the curler part (2) as an enlarged section "A" in Fig. 2. The convexly curved bimetal disc (16) in the position shown represents the electrical connection from the connection pin (15) via the contact (20) to the metal layer (8) and to the curler part (2) designed as a heating element.

...The

When the current clamp (not shown) is placed on the connection pin (6), the current flows via the contact (20), the bimetallic spring disk (16) and the metal layer (8) into the curler part (2) designed as a heating element.

After the operating temperature of the curler (1) has been reached - temperatures between 60 and 95°C are preferred as the optimal temperature for treating and shaping hair - the convexly curved bimetal spring washer (16) jumps into the flat position, as shown in Fig. 4. This interrupts the electrical connection to the connection pin (6) and prevents the curler (1) from heating up further when the current clamp (not shown) is applied.

Only after the curler (1) has cooled down does the bimetal 1-spring disc (16) spring into the convex shape as shown in Fig. 3 and thus re-establishes the electrical connection to the curler part (2) as a heating element.

The arrangement of the bimetal spring disk (16) according to the present invention completely eliminates overheating of the curler (2) wound into the human hair and thus the risk of injury to the scalp through burns. Even if the current clamp (not shown) is repeatedly connected to the connection pins (5 and 6), the flow of current to the curler part (2) as a heating element remains interrupted as long as the optimum operating temperature on the curler (1) is still present and available.

The necessity and importance of installing this temperature limiter according to the invention is even greater when you consider that during a hair treatment, around 60 curlers are wound into the hair of a human head and that the possibility of the current clamp (not shown) being accidentally and repeatedly placed on the connection pins (5 and 6) cannot be ruled out.

Claims (4)

PROTECTION CLAIMS 1. Electrically heated hair curler with built-in temperature limiter for the production of permanent waves with contact surfaces and contact pins arranged on the front side, to which a detachable current clamp can be attached, via which the current flows to the heating device of the hair curler and after reaching the operating temperature the current flow is interrupted, thus preventing overheating, characterized in that on one side a bimetallic spring disk (16) is provided between the connecting pin (6) and the contact surface (8), which interrupts the current flow from the connecting pin (6) to the metal layer (8) in the hair curler part (2) after reaching the operating temperature of the hair curler part designed as a heating element (2). 2. Electrically heated hair curler according to claim 1, characterized in that when the optimum operating temperature on the hair curler (1) drops, the bimetal spring disk (16) curves convexly and the contact (20) to the connecting pin (6) again establishes the electrically conductive connection. 3. Electrically heated hair curler according to claim 1 and 2, characterized in that the cover cap (4a) has an internal circumferential ring spring (19) with which the bimetal spring disk (16) is fixed. 4. Electrically heated hair curler according to claim 1 and 2, characterized in that the annular spring (17) running around the inside of the cover cap (4a) snaps into the annular grooves (11 and 18) present on the edge formations (3).