I recently purchased the new version of BlockBase and couldn't find anything that looked similar. I believe the quilt falls into the category of a three-patch and paid particular attention to those and found nothing but I decided to check Barbara Brackman's Encyclopedia of Pieced Quilt Patterns; and she does a pattern called the Double Z (pg.389 no 3221) which is not like the one from Quilter's Cache. Barbara's book shows a block like mine but Quilter's Cache shows a block by the same name with a pinwheel in the center.
An interesting bit that I've also learned that a block very similar to the Double Z is pg 161 no 1140a was unnamed-Dakota Farmer 1926 Barbara Frietschie-Grandmother Clark. That is my maiden name and my grandmother was a quilter. I love doing research on things so all this is right my alley!
I understand Rhonda's point about copyright but with so many variations of pattern that are already available; how one person could claim something as their own, is little hard for me to understand. Copyright is so tricky and best left to those who know it. I'm not selling anything so I don't I have much to worry about, or that is what I've been told!