Quadruplanar-Inversor
The Quadruplanar inversor of Sylvester and Kempe is a generalization of Hart's inversor. Like Hart's inversor, is a mechanism that provides a perfect straight line motion without sliding guides.
The mechanism was described in 1875 by James Joseph Sylvester in the journal Nature.
Like Hart's inversor, it is based on an antiparallelogram but the rather than placing the fixed, input and output points on the sides, Sylvester recognized that the additional points could be displaced sideways off the sides, as long as they formed similar triangles. Hart's original form is simply the degenerate case of triangles with altitude zero.Gallery
In these diagrams:
- KBCD is an antiparallelogram, so KB = CD and BC = DK.
- KBA, CBB0, and CDE are similar triangles.
- * Because KB = CD, KBA and CDE are congruent triangles
- * Because BC = DK, CBB0 and KDI are congruent triangles
- A0 and B0 are fixed points.
- A0A = A0B0, i.e. A moves on a circle through B.
- E moves in a straight line
