Ruler used in mathematics
US D207794 S
Description (OCR text may contain errors)
United States Patent 0 RULER USED IN MATHEMATICS Don C. Cherrington, 862 Birdhaven Court, Lafayette, Calif. 94549 Filed May 17, 1966, Ser. No. 2,337
Term of patent 14 years (Cl. D52-6) kli'lll FIG. 1 is a plan view showing my ruler used in mathematics. The bottom plan view is similar in outline and if made of transparent material the lettering and symbols are shown reversed.
FIG. 2 is a side elevation thereof.
FIG. 3 is an end elevation thereof.
The ornamental design for a ruler used in mathematics, as shown and described.
D. 125,449 D. 195,225 D. 200,595 1,745,188 1,899,318
Patented May 30, 1967 FIG-3 FIG. 2
References Cited UNITED STATES PATENTS WALLACE R. BURKE, Primary Examiner.
J. COOPERSMITH, Assistant Examiner.