Solar Energy Technology, Inc.

Other

Sheldon B Herskovitz

Martin R Stiglitz

Jay Marlin

Carlyle J Sletten

F Sheppard Holt

E J Sletten

A syringe for extruding heated thermoplastic materials through a hollow needle is disclosed. This syringe is particularly useful in obturating root canal cavities, or other dental cavities, with gutta-percha or similar materials.

Method for filling a root canal

Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

Internal absorber solar collector

An electrically heated endodontic syringe for injecting thermoplastic material, such as gutta percha, into a root canal cavity includes a syringe barrel for holding a supply of thermoplastic material, a heater body threadedly attached at one end to the syringe barrel and an injection needle threadedly secured to the other end of the heater body by means of a hub. A manual plunger is provided in the syringe barrel for ejecting thermoplastic material from the barrel through the heater body, hub and needle into the root canal cavity. The barrel and plunger are made of materials having a low coefficient thermal conductivity of less than about 20 Btu/(hr)(ft.sup.2) (F..degree./ft) and a thermally insulating washer is positioned between the barrel and the heater body to minimize heat transfer to the barrel. The heater body, hub and needle are made of materials having a high coefficient of thermal conductivity of at least about 200 Btu/(hr) (ft.sup.2) (.degree.F./ft) to maximize heat flow to the needle. An electric resistance heating element carried by the heater body provides sufficient heat to maintain the entire needle above 230.degree. F. at which the thermoplastic material will flow but below the temperature at which the material thermally decomposes. The needle is at least one inch long, of 18-30 gauge size, and manually malleable to enable the needle to be bent to conform to the root canal cavity.

Growing community of inventors

Acton, MA, United States of America

Sheldon B Herskovitz