CHARLES D FLANAGAN
Engineering in South Attleboro, MA
License number
Massachusetts 14690
Expiration Date
Jun 30, 1984
Type
Mechanical Engineer
Address
Address
South Attleboro, MA 02703
Professional information
Self-Limiting Electric Hair Curler Heater
US Patent:
3973100, Aug 3, 1976
Filed:
Dec 27, 1972
Appl. No.:
5/318951
Inventors:
Charles D. Flanagan - Attleboro MA
Assignee:
Texas Instruments Incorporated - Dallas TX
International Classification:
H05B 100, A45D 236, A45D 416
US Classification:
219222
Abstract:
A heated hair curler has a fast warm-up time and a slow cool down time due to a heater element having a steeply sloped positive temperature coefficient (PTC) of resistivity. The heater is composed of a ceramic like material such as doped barium titanate or a polymer loaded with conductive particles such as polyethylene loaded with carbon black. In one embodiment the heater is shaped in the form of an elongated annulus to fit closely inside a hollow plastic curler shell. Conductive coatings located on the inner and outer peripheral surfaces mate with ring shaped conductors supported in a base. In a second embodiment the PTC heating element which may be in the form of a parallelopiped is located within a sealed cylindrical container, also containing a fusible wax, which in turn fits within the hollow plastic curler shell. The PTC element has conductive coatings on two opposite faces for electrical connection thereto.