Datacard Corporation

Thomas R Emmons

Dennis J Warwick

Ronald B Howes, Jr

Robert W Lundstrom

A method and apparatus for a two-pulse solenoid embossing system implementing an amplitude feedback circuit, i.e., current monitor (48), to provide precise amplitude and timing control over two current pulses (4, 5), and thereby provide precision control over the position and velocity of the embossing system's print elements (64a, 64b). To maintain the current amplitude during the second current pulse (5), the method and apparatus alternatively switches the power on and off to the solenoid coils (55) with a frequency such that a substantially constant current amplitude is maintained in the solenoid coils (55). The embossing system provides an improved solenoid body assembly (61) including a first stack of steel laminations (93), a center block (82) and a second stack of steel laminations (81). A plunger (62) is slidably connected to the solenoid body assembly (61) by shaft (63). Cavities (79) receive dowel pins (71) which are attached to plunger (62). The cavity and dowel pin arrangement (79, 71) prevents the plunger (62) from rotating.

Apparatus for driving and controlling solenoid impact imprinter

Method and apparatus for driving and controlling an improved solenoid

A solenoid bumper mechanism wherein a resilient means absorbs a proportion of the kinetic energy of a shaft moving within the solenoid, and a nonresilient means which causes the shaft to terminate its movement at a fixed point. The mechanism provides shaft movement of repeatable precise distances and also does not interfere with the magnetic field created by the solenoid body.

Growing community of inventors

Minneapolis, MN, United States of America

Thomas R Emmons