Device for monitoring the supply of printing fluid in ink printing

Abstract

A mechanical device for monitoring the supply of ink in an ink storage reservoir carried by the printing carriage of an ink printing device is situated at one end of the path of movement for the printing carriage. The ink reservoir is mounted on the printing carriage and contains a freely reciprocable tappet member having an upstanding stem extending through the housing cover of the ink reservoir which is freely movable up and down in accordance with the level of remaining ink supply. The mechanical monitoring device is operated dependent upon the vertical position of the tappet stem each time a printing operation is begun by virtue of movement of the printing carriage toward the monitoring device so that the relative position of the tappet member may be sensed by the device. The mechanical monitoring device comprises a pivotable lever arm disposed perpendicular with respect to the movement path of the ink reservoir and printing carriage to be laterally engaged by the tappet in the event that the ink supply is sufficient and the tappet is upraised. When the lever arm is engaged, its lateral movement triggers an electrical switch which operates an electrical circuit to indicate to the operator that the ink supply is adequate. When the ink supply is too low, the tappet is lowered such that the tappet passes beneath the lever arm without engaging and the switch is not triggered, causing an alarm signal to be actuated on the ink printing device informing the operator to replenish the ink supply.