Linearly parallel multipen recorder

Abstract

A pen recorder has two movable bases adapted to be movable in directions along a platen, one of the bases being driven in directions along the platen. A plurality of pens are mounted in parallel on one of the bases, and a hammer is mounted on the other base for pressing any one of the pens toward the platen. The base which is not driven has a lock lever adapted to engage with a plurality of portions of the base which is driven. The base which is not driven further has an urging lever for driving the lock lever. The urging lever is slidably mounted on a pen changeover shaft rotated by a driving mechanism. The pen recorder further has a spring for urging the lock lever in the locking direction, as well as forcing the urging lever to abut against the lock lever in the unlocking direction. Also disclosed is a method of setting the initial position of the pen recorder. The method comprises the steps of: starting a pulse motor for pulling one of the bases under the state where the bases are connected through the lock mechanism, to move one of the bases to its dead point; making the pulse motor step out after the dead point is reached; canceling the locking to separate the bases from each other; moving the other base to its dead point; and making the pulse motor step out again after the other base reaches its dead point, thereby to set the initial positions of both the bases.