(under the class definition) Apparatus comprising (1) means for giving a signal or indication of a condition or position of some portion of the earth working apparatus or (2) means to be observed by an attendant to aid him in maintaining the apparatus on a predetermined course.
(1) Note. The mere positioning of an element of the apparatus is not considered enough to give an indication. There must be some special indicia means to come under this definition.
(2) Note. The guide means may comprise an element intended to be disposed in or aligned with a previously formed furrow
or mark, the attendant guiding the apparatus in accordance with the position of the element.
SEE OR SEARCH THIS CLASS, SUBCLASS:
126+, for apparatus comprising earth-marking means combined with an earth working element.
SEE OR SEARCH CLASS 33, Geometrical Instruments,
624+, for collocating gauge designed for setting a tool with relation to its support or with relation to work in which it is to operate and subclass 264, for sighting means attached to a vehicle to aid the driver in maintaining the vehicle on a predetermined course.
244.1, for a furrow follower for guiding a vehicle, the guiding being accomplished by reaction of the furrow follower with the walls of the furrow.
340, Communications: Electrical,
500+, for electrical automatic condition responsive indicating systems.