Writing a patent specification

A patent specification must have a specific format and content defined by law, which is intended to enable the reader to understand the invention sufficiently so that he/she can appreciate the nature of the invention and can put the invention into practice. Preparing a description of an invention with the following format will help us to draft a suitable patent specification. If it is of help, the description can include the headings given below.

1. Title

The title should reflect in very general terms the technical field of the invention. For example, the title may read "A Vehicle Disc Brake".

2. Field of the invention

The first part of the description should provide one or two sentences which amplify slightly the title to give the reader an indication of the field of the invention. It may, for example, expand the title to explain that the invention relates to "a vehicle disc brake for high performance cars".

3. Description of current techniques

The next part should describe briefly the current system(s)/method(s) considered to be the "closest" to the invention. The description need only be brief and, preferably, should refer to one or more published documents.

4. Problems with the current system/method

After each described earlier technique there should be a short list of problem(s) encountered with the technique. Typical problems which may occur with earlier systems/methods can be poor performance, poor liability, cost, difficulty in manufacture, versatility and the like.

Parts 1 to 4 thus set the scene for describing the invention by telling the reader in which technical area the invention lies, what has been done before and what problems exist with the earlier techniques.

5. What, in a sentence, is the solution you propose?

There should then be a short passage which describes the main feature or features of the invention. These ought to be listed in terms of importance. The first feature or features ought to be those which are essential to achieve the desired effect (i.e. solve the "main" problem of the art). Preferred features, in other words those which can be omitted whilst still allowing the invention to perform at least adequately, should then be mentioned (making it clear that they are preferred). Following the above example, the features may include the dimensions and/or shape of brake pad or disc, materials used, surface finishes and so on.

6. Explain in full and exact detail one example of your solution including its construction/use/operation.

This section should give clear and full technical details of the construction of the invention, how it is used and/or operated. The description needs to be sufficient to enable a person skilled in the art to put your invention into practice. It need not, therefore, start at first principles (unless the invention involves first principles). However, the description must not have any gaps which cannot be filled by general knowledge or which could only be filled with difficulty (for example only by laborious and expensive experimentation).

It is important to bear in mind that you are not allowed to add technical information to a patent application after it has been filed. Therefore, all details which have or may have a bearing on the invention should be included in the description. Features which must be included are those which affect the performance of the invention, either directly or indirectly.

Often, the simplest way to describe an invention is to start by describing all the individual apparatus or process features, than to describe how they work together and finally to identify possible modifications.

It is allowable and very useful for patent specifications to include sketches, flow charts and the like. Where these are included, it is useful to base the description on the sketches and flow charts. This makes the description considerably easier to write and understand.

7. Mention of any other techniques/modifications

Any alternative and additions/modifications included in the description should be real and reasonable. They should not include speculative additions which may not work or which cannot at this stage be described in sufficient detail to enable a skilled person to put them into practice.

8. Can you foresee any wider use or development of your solution?

If the invention could be used in other applications or could be more versatile with certain changes or development, you should mention these.

9. Outline the advantages

If the earlier part of the description does not specify all of the advantages of your invention and its preferred features, then these should be mentioned towards the end of the description. Where appropriate, you should also mention any disadvantages (which must of course be real and reasonable).

When you have prepared a description along the above lines, you can if you wish file it directly at the Patent Office with the correct form. But if you want our professional input, then make contact by any means you choose and we will discuss how to proceed and give you an idea of costs.