Method for the manufacture of a thermometer and thermometer
OwnerBernd Alberinventor
Life of this patent
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Abstract
A method for the manufacture of a thermometer provides for a bulb being formed on the thermometer capillary, a bulb receptacle being formed on the lower envelope tube end and at least over part of the receptacle its inner contour exactly corresponds to the outer contour of the bulb. The thermometer capillary is then introduced into the envelope tube and the bulb is accurately fitted into the lower part of the receptacle. In the case of a thermoareometer, the receptacle particularly serves as a weight for receiving the necessary weight-providing material, such as copper or the like.
Claims28
The method of manufacturing a glass thermometer including an inner capillary tube vessel and an outer envelope receptacle vessel and including the following steps, forming a lower end of the heat softened receptacle envelope vessel by means of a mandrel having a predetermined cylindrical shape to provide an inner contour of predetermined shape, and forming the lower end of said capillary probe vessel in a mold having a cylindrical inner surface such that a bulb end is formed to predetermined shape for closely fitting into the cylindrical receptacle contour, said forming in said mold being accomplished at least in part by blowing as the capillary tube is so provided in the mold, and fitting the complementary shaped capillary tube and envelope receptacle together so that the lower ends fit tightly together through a major portion of their surfaces to form a thermometer bulb, said envelope tube being initially closed and then, accompanied by heating to softness, the mandrel being inserted in the closed envelope tube end a distance sufficient to provide an accurately determinable bulb shape.
A method for making thermoaerometers comprising the following steps
- (a) providing a capillary tube of glass,
- (b) blowing the glass tube so as to form a bulb at one end while simultaneously,
- (c) placing the bulb in a mold so that the bulb is formed to a shape with a spherical end portion and a cylindrical portion adjacent to the spherical end portion,
- (d) filling the tube with an expansion liquid,
- (e) heating the fluid filled tube so that the fluid rises to a predetermined height, and then wiping away any excess fluid,
- (f) calibrating the tube by reference to a known temperature,
- (g) sealing the tube at its opposite or upper end,
- (h) affixing a scale to the tube,
- (i) providing an outer envelope tube also of glass,
- (k) closing the lower end of the envelope by tapering said lower end,
- (l) heating to soften said lower end while it is so closed,
- (m) inserting a mandrel into the heat softened envelope which mandrel has an end portion corresponding to the spherical end portion and adjacent cylindrical end portion of the bulb on the thermometer so that the envelope defines a pocket to snugly receive the thermometer bulb,
- (n) placing the bulb portion into the pocket formed by the mandrel,
- (o) closing the upright end of the envelope to provide a thermometer with attached scale inside a protective outer envelope, which thermometer has a probe end defined by the closely fitted lower end portions of the thermometer and envelope for rapidly assuming the temperature of its surroundings.
In a method for making thermometers wherein a glass capillary tube is formed with a bulbous lower end portion, and wherein the capillary tube is provided in an outer envelope also of glass, the improvement comprising forming the bulb in a press and blow process within a forming mold, and forming the corresponding end of the outer glass envelope by softening the glass and expanding the end portion as a result of forcing a mandrel into the end of the envelope, and providing these end portions of the glass capillary tube and envelope in intimate contact with one another in the area where the glass tube and glass envelope have been so formed by the mold and mandrel respectively.
Dependencies are inferred from the claim text.