PTO Wrapper PDF
Dossier Espace Google
Patent
   D531672
Priority
Jan 04 2005
Filed
Jan 04 2005
Issued
Nov 07 2006
Expiry
Nov 07 2020
Inventors
Hannon, Br…
Assg.orig
Assg.curr
Entity
unknown
Referenced by
6
References
7
Maint.:
n/a
The ornamental design for a pi illustration display device, as shown.

Within a transparent rectangle, balls illustrating the length of the circumference of a circle travel in hollow tubular channel.

FIG. 1 is an isometric view of the PI illustration display device.

FIG. 2 is a front view of the PI illustration display device.

FIG. 3 is a side view of the PI illustration display device; and,

FIG. 4 is a top view of the PI illustration display device.
INVENTORS:

Hannon, Bruce

THIS PATENT IS REFERENCED BY THESE PATENTS:
Patent Priority Assignee Title
D549286, Jun 27 2006 ESSILOR INTERNATIONAL COMPAGNIE GENERALE D OPTIQUE Demonstrator of optical phenomena in a case
D566767, Sep 14 2005 Teacher's aid
D571401, Nov 08 2007 Transparent tank
D590019, Sep 14 2005 Aid for teaching projection drawing
D726818, Jul 17 2014 Merit Medical Systems, Inc Human central venous anatomy demonstration device
D784449, Oct 07 2015 Visual aid that demonstrates a random walk and generates a bell curve distribution
THIS PATENT REFERENCES THESE PATENTS:
Patent Priority Assignee Title
4400162, Apr 05 1982 Planetarium
5470234, Jun 16 1993 Circular, piece-matching math educational aid
5823783, Jun 14 1995 Rotating pie graph: mathematics learning tool
6293800, May 13 1999 Educational and entertainment device
7025593, Nov 20 2003 Gerald, Bauldock, Sr. Teaching circumference instrument
D474250, Nov 29 2001 Solar system toy
D486183, Jan 09 2002 Coin teaching set
ASSIGNMENT RECORDS    Assignment records on the USPTO
Executed onAssignorAssigneeConveyanceFrameReelDoc
MAINTENANCE FEES AND DATES:    Maintenance records on the USPTO
n/a
Date Maintenance Fee Events


n/a
Date Maintenance Schedule