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# Print Hammer Rebound Dampener

IP.com Disclosure Number: IPCOM000040406D
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 61K

IBM

## Related People

Mathews, RD: AUTHOR

## Abstract

In a printer print hammer damper, a transfer mass is used to transfer energy from a rebounding hammer to a secondary mass which, together with its spring, dissipates that energy. Due to this energy transfer, the hammer comes to rest almost instantaneously upon reaching its home position and is immediately available for the next print cycle. The problem is illustrated by the curve plotted in Fig. 1 which shows that the hammer bounces after reacing its home position and therefore the total time from hammer actuation to hammer again at res, t actual, is much greater that the ideal, t ultimate. It is apparent that this settling-down time reduces the hammer cycle repetition rate. Figs. 2, 3, and 4 show schematically the present embodiment at three sequential instants of time, together with corresponding displacement vs.

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Print Hammer Rebound Dampener

In a printer print hammer damper, a transfer mass is used to transfer energy from a rebounding hammer to a secondary mass which, together with its spring, dissipates that energy. Due to this energy transfer, the hammer comes to rest almost instantaneously upon reaching its home position and is immediately available for the next print cycle. The problem is illustrated by the curve plotted in Fig. 1 which shows that the hammer bounces after reacing its home position and therefore the total time from hammer actuation to hammer again at res, t actual, is much greater that the ideal, t ultimate. It is apparent that this settling-down time reduces the hammer cycle repetition rate. Figs. 2, 3, and 4 show schematically the present embodiment at three sequential instants of time, together with corresponding displacement vs. time curves. Fig. 2 shows that hammer 1 has achieved impact and, urged by spring 2, is moving towards transfer mass 3 at home position. Transfer mass 3 is in physical contact with secondary mass 4, which is supported by spring 5. An instant later, at the of t u (Fig. 3), hammer 1 has arrived at its physical home position in contact with transfer mass 3, which transfers hammer energy to secondary mass 4. Secondary mass 4 bounds away from transfer mass 3 (Fig. 4), leaving transfer mass 3 and hammer 1 completely at rest. Secondary mass 4 pulls on spring 5, causing its arms to rub on surface 6. This friction dissipates seconda...