Expansible proportional rule

Description

FIG. 1 is a top plan view of an expansible proportional rule showing my new design;

FIG. 2 is a front edge elevational view thereof, the raised portions of the rear edge having been omitted for ease of illustration;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a rear edge elevational view thereof, the raised portions of the front edge having been omitted for ease of illustration;

FIG. 5 is a left end elevational view thereof;

FIG. 6 is a right end elevational view thereof;

FIG. 7 is a top plan view of another embodiment of my new design of FIGS. 1-6;

FIG. 8 is a front edge elevational view thereof, the raised portions of the front edge having been omitted for ease of illustration;

FIG. 9 is a bottom plan view thereof;

FIG. 10 is a left end elevational view thereof;

FIG. 11 is right end elevational view thereof;

FIG. 12 is a top plan view of a third embodiment of my new design of FIGS. 1-6, the bottom plan view being identical to FIG. 3;

FIG. 13 is a typical front or rear edge elevational view of the third and fourth embodiments of the design;

FIG. 14 is a typical left or right end elevational view of the third and fourth embodiments of the design;

FIG. 15 is a top plan view of a fourth embodiment of my new design of FIGS. 1-6, the bottom plan view being flat, plain and unornamented.

FIG. 3, besides being an illustration of the reverse face of the embodiment of the Rule of FIG. 1, is also a true visual representation of the reverse face of the Rule embodiment of FIG. 12; and

The reverse face of the embodiment of FIG. 15, which is not shown, is blank (i.e., without graduation scales).