https://www.google.com/patents/US5628016
https://www.google.com/patents/US6247169
https://patents.google.com/patent/US20070016894A1
I'm not sure about the last one since it's an apparently abandoned application rather than a granted patent...
Interestingly, US6247169 reports "lapsed" on the google page due to non-payment of fees...
I'm really not sure what to make of US5628016 - it's filing date is in 1994, but there's a report of a 2015 "Assignment" legal event.
(edit - fixed links)