.~ Open-ended hollow skirt type (e.g., trunk type) {15}
212
.~.~ With nonmetallic portion
DEFINITION
Classification: 92/212
(under subclass 208) Apparatus in which the piston includes as an element thereof a portion which is formed of material other than metal.
(1) Note. Since few trunk type pistons include nonmetallic parts, all trunk type pistons which include a part formed of nonmetallic material are classified in this subclass. Normally the nonmetallic portion is for the purpose of modifying the transfer of heat between piston parts.
