US 7,080,942 B2 · Bimetal thermometer

Abstract

The bimetal thermometer according to the invention comprises a bimetal helix arranged inside a protective tube, one end thereof being attached to the protective tube and the other end thereof being connected to a pointer shaft to which a pointer arranged inside a casing is attached. The pointer shaft is rotatably journaled in a bearing assembly in which a cavity is formed through which the pointer shaft extends. The cavity is filled with semisolid lubricating grease for damping vibration movements of the pointer shaft. The pointer shaft has either a smooth surface or is provided with at least one radial projection arranged inside the cavity. Vibration movements of the pointer shaft are damped by the interaction of the pointer shaft and, if provided, the projections with the viscous lubricating grease. This design of the bearing assembly and the pointer shaft permits to provide a damped bimetal thermometer without a liquid filling being required in the casing and the protective tube or at least in the protective tube for the purpose of damping.

Claims18

Dependent claims

A bimetal thermometer comprising

a cup-shaped gas filled casing which has a bottom wall and supports a window at its edge opposed to the bottom wall,
a casing carrier to which the bottom wall is attached,
a protective gas filled tube having a free closed end and being connected to the casing carrier at its other end, and
a bimetal helix arranged inside the protective tube and attached with its first end to the free end of the protective tube,
wherein a dial and a pointer which is fastened to a pointer shaft are arranged inside the casing, and
a bearing assembly wherein the pointer shaft is rotatably journaled, said pointer shaft extending through the bearing assembly and casing carrier and being connected to a second end of the bimetal helix such that a temperature-dependent rotation of the second end of the bimetal helix causes a rotation of the pointer shaft,
wherein the improvement comprises that the bearing assembly has a cavity through which the pointer shaft extends, said bearing assembly including a bushing and a closure element defining said cavity and
that the cavity is filled with lubricating grease.

5 more elements

Dependencies are inferred from the claim text.

Bimetal thermometer

Life of this patent

Bimetal thermometer

Life of this patent

Abstract

Claims18