US5007257 still in force?

[servux]

Hello,
Does somebody can figure out if patent US5007257 (safety shield for double-lock handcuffs) is still in force?
I know that normally patents are in force for 20 years. Because this patent was filed on Oct. 9 1990 it should be invalid.
But I am confused because of the assignments (the latest from year 2015) done when the patent should already be invalid ( why to do an assignment when the patent is already invalid?).
I searched for example here:
http://portal.uspto.gov/pair/PublicPair

Thank you very much for your help,
servux

[EPO / Espacenet helpdesk]

Dear Espacenet User,

The EPO relies on the bulk deliveries from the various national patent offices regarding the publication of their patent applications.

In this case, you already found legal status information under the "INPADOC legal status" link.

I would suggest you to contact the US Patent and Trademark Office to obtain more current and precise legal status information :

http://www.uspto.gov/

Kind regards,
Patent Information User Support