The invention relates to hair curling rollers and to a new way of heating them. It refers particularly to a complete set comprising a case and rollers positioned therein and to a new method of transferring heat energy from the case to the individual rollers.
A conventional hair curling set consists of a case provided with a plurality of upstanding electrically heated posts and a number of rollers, usually of different diameters, positioned on these posts to be heated to the required temperature. The rollers are usually cylindrical, provided with hair-gripping means on their circumference, and contain thermally insulated portions to allow their handling without the danger of burning the user's fingers. They are hollowed out in their bottom portion for being placed onto the posts for the sake of heat transfer from post to roller. The case is usually closed by a cover which retains the heat during warming up. Various types of rollers are on the market: there are rollers of metal and of plastic material, or rollers having a metal core or sleeve and a plastic outer shell; some rollers are provided with bristles, and others with outstanding teeth. Other kinds are filled with a heat-retaining melting liquid, but all have the common feature of being hollowed out for being placed on the heated posts.
The posts are occasionally heated individually by an electric heating element inserted into each post. This arrangement is relatively expensive and adds considerable weight to the set. In most instances, the entire bottom of the case is heated by electric resistor means and heat energy is transferred to each post mostly by convection. In this way, much heat is dissipated and heating-up takes a long time. Also, the existing hair curling sets are of excessive height due to the vertical posts and the rollers placed thereon, a fact which makes storage inconvenient, especially on a trip away from home, when modern flat suitcases are used. An example of such an arrangement is disclosed in U.S. Pat. No. 4,489,233 (Glucksman). The above drawback is overcome in the hair curling set of the present invention which has as one of its objects to provide flat cases, by placing the rollers flat on the bottom of the box containing them at the same time.
It is another object to provide the curler case with simple and inexpensive heater means which provides rapid heat transfer to the rollers; and it is a final object to permit ready withdrawal of individual rollers and their repositioning from and into the case, without any major effort.