It's easy to do online patent searching on the US Patent Office web site uspto.gov - the direct link to the search query is
http://patft.uspto.gov/netahtml/search-bool.html.
(Patent searches at
http://ep.espacenet.com covers more countries, though not all.)
A US patent issued more than 17 years ago (1987) is presumably expired (BUT some patents have had their terms extended, so you can't know for sure until you check a particular patent).
Apparently the Glock patents don't list a corporate assignee, but following are the patents which list Gaston Glock as inventor:
PAT. NO. Title
1 6,643,968 Pistol with a device for determining the number of shots
2 6,478,202 Holster
3 6,276,581 Holster for a firearm
4 6,230,414 Rear sight for firearm
5 5,485,695 Laser aiming device
6 4,893,546 Automatic pistol
7 4,825,744 Automatic pistol
8 4,539,889 Automatic pistol with counteracting spring control mechanism
9 4,475,757 Spade
Numbers 6 and 7 in this list still appear to have some lifetime left. I don't know which patents were involved in their lawsuit against S&W - perhaps someone can confirm?