US PATENT SUBCLASS 104 / 167
.~ Helical


Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use



104 /   HD   RAILWAYS

165  DF  TRACTION {8}
167.~ Helical


DEFINITION

Classification: 104/167

(under subclass 165) Car-propelling means in which rotary shafts along the track are provided with helical or screw surfaces for propelling the car, on the principle of the screw or worm gear.