In this paper, we will undertake a graphic analysis of the most unknown patents and utility models of great Spanish architects, which were registered between 1950 and 1970. Inventions that proposed improvements in manufacturing processes and construction elements, furniture, and novel spatial solutions, as well as others that brought significant advances in the discipline of drawing. The drawings submitted when applying for a patent or utility model constitute per se the formal definition of the invention and must illustrate elements that lead to a better understanding of what the invention represents, with the aim of facilitating its comprehension in support of the specification. The graphic resources that architects could use to represent their inventions were scarce, as they were subject to the Royal Decree-Law of 1929, which allowed them to choose the scale and the system of representation for each drawing. We will analyze the common features of the drawings accompanying the inventions, which must, above all, be clarifying and unambiguous.