Interlock for Preventing Ribbon Break
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
A resistive ribbon is prevented from being broken during installation through locking a printhead actuation gear when a load lever is left open, the ribbon is loaded with slack, or the thermal printhead is resting on a cam ramp rather than a dwell when in its home position. A ribbon 1 has a spring-loaded ribbon brake arm 2 engaging therewith. If the ribbon 1 is slack when installed, the spring-loaded ribbon brake arm 2 rotates clockwise about its pivot 3 to the dashed line position to cause teeth 4 of the ribbon brake arm 2 to engage teeth 5 on a head-actuation gear 6, which rotates a thermal printhead (not shown), to prevent the head-actuation gear 6 from rotating counterclockwise to rotate the printhead. If an operator tries to type with the teeth 4 and 5 engaging, an error signal and an error light code are received.