Electrically heated hair curling instrument and temperature control stand therefore

A hair curling instrument comprising:

• (a) an electrically-operated curling iron;
• (b) a stand having means for supporting said curling iron when not in use;
• (c) a temperature control box mounted on said stand;
• (d) an electric cord for carrying electric power from the control box to the curling iron;
• (e) said curling iron comprising a handle assembly, a detachable heating element mounted on the end of said handle assembly and a hair-clamping means pivotally mounted on said handle assembly;
• (f) said handle assembly comprising a handle, a mandrel rotatably mounted within said handle, a plurality of slip rings secured to one end of said mandrel, means for connecting each wire of said electric cord to a different one of said rings, a first electrical connector member having a plurality of terminals secured to the other end of said mandrel, and means for electrically interconnecting each of said slip rings to a different terminal of said first connector member;
• (g) said heating element comprising an open-ended hollow mandrel, two longitudinally-spaced heating coils electrically connected in series and mounted on said hollow mandrel, an outer heat-conducting tube covering said coils and having a closed end, a thermistor mounted on said mandrel between said heating coils and contacting the inside of said heat-conducting tube for measuring the temperature of said tube, a second electrical connector member having a plurality of terminals corresponding to the terminals of said first connector member and secured to the other end of said outer tube means for interconnecting said heating coils and said thermistor to different terminals of said second connector member, said second connector member having its terminals removably coupled to the corresponding terminals of said first connector member carried by said handle assembly;
• (h) and a manually-adjustable temperature control circuit located in said control box, connected to said thermistor through wires of said power cord, said slip rings and first and second connector members and responsive to the temperature of the curling iron as measured by said thermistor for controlling the de-energization of the curling iron, depending on the type of hair being curled.