HP card reader drive coupling

[Geoff Quickfall]

We can all agree it is not a clutch, never was. The use of the word dampening coupler was anecdotical from the last 10 years at HCC meetings. Including a discussion with people associated with the design.

I thought I saw it in a manual but having perused the HP-97 and 41C card reader service manual I do not see it referred to except as the drive mechanism.

Since it is made out of the same material as the original pinch roller the thought was, prior to it decomposing that it would take out some vibration including at a higher frequency. As it decomposes, I have found that it self destructs in two ways: it hardens, then crumbles or it turns into goo. In both cases it slips and does not transfer the torque from the motor to the worm gear. The assumption was that in its pristine shape (New from the factory) that it had dampening qualities due to it being more pliable. It certainly did not age well as seen in so many HP applications such as the 97 printer, 9825a tape drives, all card readers and etc. Again only anecdotal from conversations at HCC.

None of this is explained in the manual but only referred to as a couple, never a clutch.

Cheers, Geoff