US 4,777,480 A · Multi-scale indicator

Abstract

A multi-scale indicator which has a main scale and a sub-scale is constructed so as to prevent a misreading between the main scale and the sub-scale. A sub-scale prism and the light source which illuminates only the sub-scale are light insulated from the main scale prism and the light source which illuminates the main scale, due to the sub-scale prism being securely buried within a circular arc shaped prism receiving groove which is formed on the main scale prism. Light opaque paint is spread between the main scale prism and the sub-scale prism to prevent the occurrence of light leakage therebetween. Also provided is an electrical control for supplying a light to the sub-scale prism only when the pointer is moved to a predetermined zone located on the end of the main scale.

Claims7

Dependent claims

A multi-scale indicator comprising:

a pointer for indicating measured values of the indicator;
a scale disc having a main scale and a sub-scale;
a main scale prism for illuminating said main scale by a light derived from a first light source, which is attached to the back side of said scale disc, and said main scale prism having a prism receiving groove formed on said main scale so as to leave a light transmitting passageway thereunder for introducing a light from said first light source into said pointer;
and
a sub-scale prism for illuminating only said sub-scale by a light derived from a second light source, which sub-scale prism is light insulated from said main scale prism and is buried securely within said main scale prism.

2 more elements

Dependencies are inferred from the claim text.

Multi-scale indicator

Life of this patent

Multi-scale indicator

Life of this patent

Abstract

Claims7