Printhead Printwire and Return Spring Checking Device
Original Publication Date: 1988-Sep-01
Included in the Prior Art Database: 2005-Feb-15
In the automated assembly of a wire printer printhead the printwires and their return springs are inserted in the wireguide prior to the assembly of the wireguide together with the magnet subassembly. After this assembly operation the unit is checked by the present embodiment to detect broken or missing print wires or missing springs by successively energizing each print magnet coil and optically sensing the actuation and return of the corresponding printwire. Referring to the figure it is seen that printhead assembly 1 is brought into a work station and oriented and clamped by mechanisms 2 and 3 so that the face of the wireguide plate is in close proximity to detector lever 4. Mechanism 5 then moves into position so that contact pins 6 close on contact lands on PC board 7.