Throwaway plastic thermometer structure

Abstract

A throwaway thermometer structure (10,110) comprising essentially a synthetic resin wall member (13,113) having a thin gas impermeable layer (11,111) defining the inner capillary bore (12,112) thereof. The outer wall member effectively defines a jacket and the inner layer effectively defines a core tube. Interlock structure (20,120) is provided for effectively accurately maintaining the longitudinal disposition of the jacket and core tube. Such maintained disposition provides effective accurate maintained disposition of a scale (17) or the like, provided on the jacket portion of the thermometer. In one form, the interlock (20) may be directly between the jacket and the core tube. In an alternate form, the interlock (120) is indirectly between the jacket and core tube, being effectively provided between the reservoir bulb (114) and the core tube (111), with the reservoir bulb being fixedly secured to the jacket. The interlock structure may further define a constricted portion (23,123) of the capillary bore for releasably preventing return of the indicator liquid to the reservoir bulb upon completion of the temperature sensing operation. The jacket may be molded in place or provided as a preformed element, as desired.

Dependencies are inferred from the claim text.