.~ With at least one surface-engaging propulsion element {6}
187
.~.~ Element shuffles along support surface
DEFINITION
Classification: 180/187
Element shuffles along support surface:
(under subclass 186) Vehicle wherein at least one surface containing propulsion element propels the vehicle by alternately (a) freely sliding upon, or slightly above and generally parallel to, the supporting surface away from a point on the vehicle and (b) firmly engaging the supporting surface and pulling the point on the vehicle towards it.
(1) Note. The element may be a member in the sense of subclass 182.