Layouts of spatial motion structures 143
and the interconnected Bennett linkages around it, which are marked with
numbers 1 to 8, have lengths a i , b i and twists α i , β i (i = 1, 2, . . ., 8). It can be
found that the mobility conditions for this assembly are as follows (Chen
and You, 2008b).
(7.5a)
or
(a)
(b)
Figure 7.5 (a) A Case III building block based on the Bennett linkage and (b)
assembly of the building blocks.