Copyright is a difficult and vague area. You can't sell someone else's work and claim it as your own. If you are teaching a class using someone else's copyrighted pattern each person must have his own copy of the pattern or book.
On the other hand, if you are teaching a beginning quilting class, say a regular nine patch with offsetting solid blocks... Probably can't find a copyright on that (and if you did, the claimant is probably lying, and should be dead because that block has been around longer than any of us).
It seems to me that if libraries are allowed to lend books (and unless it is digital they don't pay extra for the privilege as far as I know ---any librarians out there?) So can I. But neither I or the person to whom I lend a book can claim we are the source and owner of the pattern or that it is our original work (the quilt however is our work). If I lent my friend my copy of Moby Dick, and she decided to copy it (by hand with a quill) she still could not claim it as her own original work. I think a quilt book is not all that different. When you buy a book of any sort you can lend it or sell it or add it to the large pile in the corner. It is yours to do with as you please. On the other hand, copying those stacks of sheets for a paper piecing pattern is no fair and probably does constitute copyright violations.