| US 7,461,459 B2 | ||
| Instrument for drawing ellipse or the like | ||
| Yu-Hui Lin, 7F, No. 12, Lane 16, Shuanghe St., Yonghe City, Taipei County (Taiwan) | ||
| Filed on Jan. 12, 2007, as Appl. No. 11/652,887. | ||
| Prior Publication US 2008/0168668 A1, Jul. 17, 2008 | ||
| Int. Cl. B43L 11/00 (2006.01); B43L 11/05 (2006.01) | ||
| U.S. Cl. 33—30.6 [33/27.03] | 2 Claims |

| 1. A compass comprising:
an upright turning assembly including a top disc, a rotatable handle extending from the disc, a cylindrical post, an upper
first bevel gear extending downward from the disc and adapted to rotate about an upper portion of the post, a pointed center
at a bottom end of the post, a bar extending from a first position of the post proximate the center, and a socket at an open
end of the bar;
a gear assembly including a second bevel gear meshed with the first bevel gear, the second bevel gear including, a shaft having
one end connected to and adapted to rotate about a second position of the post below the first bevel gear, a gearwheel meshed
with the second bevel gear and having a shaft having one end inserted through a third position of the post below the second
position and adapted to rotate about the third position of the post, and a wheel secured to the other end the shaft of the
gearwheel and including a plurality of holes arranged as an arc;
a link assembly including a first link having an upper end pivotably secured to one of the holes, and a second link including
an upper first section having an upper end pivotably secured to a lower end of the first link, and a lower second section
adjustably secured to the first section and moveably received in the socket; and
a drawing assembly including a horizontal arm having one end secured to a lower portion of the post, the arm including a scale
and a lengthwise groove, a wheeled support at the other end of the arm, a third link having an upper end pivotably adjustably
secured to the second section, and a lower end pivotably slidably fastened in the groove, a slider having one end secured
to the lower end of the third link and the other end slidably fastened in the groove, the slider including a lengthwise trough,
and a pen mounting bed including a fastener for adjustably securing the pen mounting bed to the groove and the trough;
whereby positioning the center and continuously rotating the handle in a first predetermined direction will turn the first
bevel gear, causing the second bevel gear, the gearwheel, the wheel to rotate, causing the upper end of the first link to
move the second link up and down repeatedly and repeatedly slide the slider back and forth with the pen mounting bed traveling
around the center until an arcuate shape is drawn.
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