This invention relates generally to measuring instruments and more particularly to an improved caliper rule device having an extended measurement range.
Although caliper rule measuring instruments have long been in widespread use, they have not been entirely satisfactory in all respects. A typical caliper rule has a relatively small range and is incapable of measuring dimensions which are larger than the range of the instrument. Consequently, a number of different caliper rules having various measurement ranges must be kept on hand if objects having widely varying sizes are to be measured.
The present invention has as its primary object the provision of an improved caliper rule which has an extended measurement range.
Another object of the invention is to provide a caliper rule device which is capable of accurately measuring both the inside and outside dimension of objects which vary widely in size.
A further object of the invention is to provide a caliper rule device of the character described in which the apparatus for extending the measurement range can be readily attached to a conventional caliper rule in order to extend its range.
An additional object of the invention is to provide a caliper rule device of the character described which is simple and economical to construct and which may be in the form of a complete instrument or in the form of an attachment which can be added to an existing caliper rule.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.