Print Hammer With Nearly Constant Dissipation
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
The printing energy and flight time of a print hammer remains nearly constant over a wide temperature range by providing the canceling effect of dimensional changes in a controlled gap formed within structural members of a reactive mass energy damping device. In the figure, hammer push rod 1 is urged to the right under the influence of a hammer return spring acting through a hammer, neither of which is shown. The push rod forces unattracted armature 2 counter clockwise about pivot 3 so that armature tailpiece 4 rests initially against polyurethane pad 5 on reactive mass 6. The reactive mass is supported by stem 7 in an energy absorbing material 8, such as butyl rubber. Spring 9 in fixed frame member 10 acts through pin 11 urging the top portion of mass 6 against polyurethane pad 12 on fixed stop 13.