Hmmm... if giving someone a copy of a pattern that is published in a quilt book is a violation of copyright...then giving someone a recipe out of a published cookbook would be as well, wouldn't it?
If a pattern designed by an artist is going to be published in a book, the artist is paid for their work by the publisher, doesn't matter how many books sell, they were paid an agreed upon amount. I buy a pattern book, someone sees a pattern in it they want to make, as long as they are not claiming the finished product as their own design, or selling it for personal gain, you haven't infringed on any copyright laws. This would fall under the 'fair use' clause in copyright statutes, at least in Canada's copyright law., not sure what the copyright laws are in the U.S.
I ran into a situation when I owned an Internet Service Provider. Web sites I designed, the copyright belonged to my Corporation. One of my customers downloaded a picture off my Corporate site and put it up on their own site, but didn't reference the picture back to my company. That was copyright infringement. Could I have filed a law suit? If I wanted to send my corporate lawyer on another trip to the Caribbean..sure. A simple request that they either take the picture down, or make reference to it being copy written to my company was the advice my lawyer gave me. Saved me a lot of money, and my lawyer had to endure another cold winter... LOL
Not claiming to be an authority...just my view and experience...