The CA must be referenced to the DD so that no misunderstanding can arise as to what the pledge of confidence is about. Such help might be in reduction to practice, artistic design, improvements in concept or construction, etc. The WA is very important because, by law, ALL true inventors must be specified in your U.S. patent application. Contractor compensation may be salary, fixed contract price, or a percent of the first profits, but should not be a percent of ownership in the patents which carry some of the contractor's inventive contribution. The WA legally binds the contractor to transfer his rights in any patents for the compensation paid for his work, even if the compensation occurs in the future, i.e., option rights, etc.
Rights transferred are for U.S. and foreign patents and any continuations, divisions, and reissues.
The contractor is also obliged to help perfect your patents. A copy of a typical agreement is included in order to give you an idea of some of the language involved. Please don't try to negotiate such an agreement without professional help. The patent or pending patent should be clearly identified as well as the names, addresses and entity status of each of the parties. The LA gives rights of making, using, and, or selling for products protected under law by the patent grants or potential patent grants.