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Patent
   D317787
Priority
Aug 22 1989
Filed
Feb 21 1990
Issued
Jun 25 1991
Expiry
Jun 25 2005
Inventors
Davidson, …
Assg.orig
Assg.curr
Entity
unknown
Referenced by
2
References
4
Maint.:
n/a
The ornamental design of a mathematical aid, as shown and described.

FIG. 1 is a top perspective view of a mathematical aid showing our new design; and

FIG. 2 is a bottom plan view thereof.
INVENTORS:

Davidson, William A., Davidson, Silvia, Charters, John D.

THIS PATENT IS REFERENCED BY THESE PATENTS:
Patent Priority Assignee Title
D374048, Jun 02 1995 Coordination enhancement device
D668575, Jul 26 2010 Baby-entertaining necklace
THIS PATENT REFERENCES THESE PATENTS:
Patent Priority Assignee Title
217770,
231738,
241856,
D265666, Apr 22 1980 Combi Co., Ltd. Educational toy rattle
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