HP and/or Seiko-Epson IC memory card patent(s)?

[Jonathan Busby]

I've been trying to find the patent(s) for the ESD protection mechanism used on official HP and also Seiko-Epson ( on which the HP memory cards are based ) IC RAM / memory cards. The ESD protection consists of a small, spring-loaded metal protector that retracts from the card-edge contacts when the memory card is inserted into the calculator ( 48SX/GX ). I've searched the web, used the USPTO's full text patent search with complex boolean searches, the same with Google Patents and the comp.sys.hp48 Usenet archives on groups.google.com and I've found nothing relevant. If someone could point me to where I can find the relevant patents I'd be very appreciative.

Thanks,
Jonathan