Is there any easy toddlers jumper patterns to make?
There are patterns available almost everywhere. I would start right here at Knitting Daily and search their pattern database. They may have just what you are looking for. Another good source is the website for the yarn that you are planning on using for the project. Often the yarn websites have free patterns to download. Check also at your LYS. Often your fellow knitters may have a pattern they are willing to share or can head you in the right direction.
Those are good suggestions for places to look. Here are a couple that seem easy too:
http://www.lionbrand.com/patterns/70216A.html (you'll probably have to register on the Lionbrnad site)
I don't want 18 months i want 3 to 4 years
You could make one your self. Have look at http://knittingpatterns.is