A patent may be sold giving a divided, or an undivided right.
A divided right is where a State, or any other particular territorial right is granted. An undivided right is a quarter, or a half, or some other portion in the patent itself.
If an inventor assigns his invention, and states in the granting clause that he conveys "all his right and title in and to the invention," or words to that effect, he conveys all his rights throughout the world.
If the conveyance says, "all rights and title in and throughout the United States," he thereby reserves all other countries.
If a patent is issued, and the number and date of the patent are given, the assignment conveys the patent for the United States only, unless foreign countries are specifically mentioned.
To convey an invention or patent, some definite[p. 193] number or filing date must be given in the document, with sufficient clearness and certainty to show the intent of the assignor.
An invention does not depend on quantity, but on quality. It is that which produces a new and a useful result.
In the United States patents are granted for the purpose of promoting the useful arts and sciences.
In England, and in many other foreign countries, patents are granted, not on account of any merit on the part of the inventor, but as a favor of the crown, or sovereign.
Originally patents were granted by the crown for the exclusive privilege in dealing in any commodity, and for this right a royal fee was exacted. From this fact the term royalty originated.