If the patentability search reveals no reference which exactly discloses or anticipates the invention, and if the patents disclosed in the search do not overly restrict available patent coverage, the inventor may desire to pursue a patent. A patent application must be prepared and filed in the U.S. Patent and Trademark Office. The application usually includes a written description of the invention, one or more sheets of drawings having figures which disclose the invention by showing its component parts and construction, the government filing fee, and the legal protection sought in the form of one or more patent claims. The drawings are extremely important, and should accurately show the invention. Once the application is received and accepted by the Patent and Trademark Office, the Patent and Trademark Office assigns the patent application a filing date and serial number.

Technical requirements of a patent application are set forth in 35 U.S.C. § 112, reproduced below:

35 U.S.C. § 112. Specification

• In General. – The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or a joint inventor of carrying out his invention.

• – The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as his invention.

• – A claim may be written in independent or, if the nature of the case admits, in dependent or multiple dependent form.

• Reference in Dependent Forms. – Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.

• Reference in Multiple Dependent Form. – A claim in multiple dependent form shall contain a reference, in the alternative only, to more than one claim previously set forth and then specify a further limitation of the subject matter claimed. A multiple dependent claim shall not serve as a basis for any other multiple dependent claim. A multiple dependent claim shall be construed to incorporate by reference all the limitations of the particular claim in relation to which it is being considered.

• Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.

If the invention has been made, one good way to comply with the requirements of the subsection (a) of 35 USC Section 112 is to list all parts used in the invention by name, manufacturer, and part number, then to explain how, if one could improve the invention as much as the inventor contemplates, one would modify that parts list. The description should be detailed enough to allow one of ordinary skill in the relevant technology to make the invention without undue experimentation.

To allow latitude when claiming the invention, it is useful to include in the patent application ranges of ingredients, sizes, capacities, or other physical properties of the invention. It may also be useful to include lower limits and/or upper limits. One may also wish to express relationships between various elements of the invention. It is useful to include various ranges (such as a preferred range (broader), a more preferred range (tighter), and a most preferred range (tightest)), so that, if patents are found which indicate that one of the broader ranges is anticipated or obvious, it might be possible to restrict the claims to one of the tighter ranges and still get a patent on the invention. For example, if the ideal percentage of element A is 25%, one might disclose that the amount of element A in the invention is, by weight, 1%-50%, preferably 10%-40%, more preferably 20%-30%, and most preferably about 24%-26%. As another example, one might state that element B is at least twice as long as element C, more preferably at least four times as long, and most preferably at least six times as long. As a third example, one might state that the resistance of an element is less than 1 million ohms, preferably less than 500,000 ohms, more preferably less than 250,000 ohms, and most preferably less than 100,000 ohms. Also, one may wish to generalize a bit – instead of merely mentioning that a certain plastic (such as PVC) could be used to make the invention, one could state that any relatively flexible, non-electrically conductive material could be used, such as flexible, non-electrically conductive plastic, such as polybutylene or PVC, and preferably PVC. When one describes an element of an invention, one should think about why that element is made of a certain material, and try to think of other materials which could work almost as well, and perhaps list them as alternative materials.

An inventor should also disclose to a patent attorney the background of the invention, including the problem that the invention solves, other technologies to which the teachings of the invention might be applied, how the industry in which the invention is used might change and how the change may affect the applicability of the invention, and how competitors of the inventor will likely try to copy the teaching of the invention while attempting to avoid infringement of the claims of the patent application.

In the U.S., one ultimately must choose trade secret protection or patent protection – one cannot disclose just part of an invention and keep the preferred way to make it a trade secret – the best mode disclosure requirement of 35 U.S.C. Section 112(a) prohibits this. However, strictly commercial information (such as which supplier of identical products has the best prices, or how most effectively to market an invention) need not be disclosed in a patent application.

When possible, include S.I. (metric) units as well as English.