How to review a draft patent specification

A patent application is typically made up of five main parts: summary of invention, description, claims, drawings and abstract. The summary of invention, description and claims are usually contained in the patent specification. The patent application will include a title which gives a general indication of your invention. If you are in the process of filing a patent application, it is likely that your patent attorney will ask you to review the draft specification and drawings so that you can approve these documents before they are filed.

It is important to review the draft patent specification and drawings carefully because it is not possible to add subject matter to a patent application once it has been filed. The documents can only be changed or modified under certain limited circumstances, for example to correct obvious errors when the correction is also obvious.

In this article we discuss how inventors should review draft patent specifications which we have prepared. This approach is also useful with many patent specifications drafted by other European patent attorneys but does not apply to applications drafted in the US and many other countries.

Claims

You should start your review near the end of the document, by looking at the patent claims. The claims are a collection of numbered statements which set out the extent of the scope of protection you are seeking for your invention and so are especially important. The claims can be directed towards different categories for the same invention, for example some claims may be directed to a method whilst others may be directed to an apparatus that performs the method. It is common to include both method and apparatus claims in a patent application.

Claim 1 is an independent claim which defines the broadest scope of protection for the apparatus or method of your invention. There may be other independent claims. An independent claim is a claim which does not refer to any earlier claims. An independent claim seeks to protect an apparatus or a method which includes every feature of the independent claim. It is important to check that the independent claims include the features which are essential to your invention, but most importantly of all, you should also check that they do not contain any features which are not essential to the invention, which a third party could omit to try to design around your patent.

The independent claims may be less specific than how you have described the invention to your patent attorney, for example you may have described that two components are secured together using a nail, but the independent claims refer to ‘a fastener’ instead. The claims are intentionally general and are not limited to specifically how you have chosen to implement your invention. This is to make it harder for third parties to design around your invention by using something other than a nail. For example, using a screw would not clearly fall within the scope of a claim that defined a nail specifically, but would clearly fall within the scope of a claim that defined the broader term of ‘a fastener’.

If there are multiple independent claims, the patent seeks to cover an apparatus or a method including all of the features of any one of the independent claims. Sometimes an application will use multiple independent claims to try to claim more than one invention - or the same invention from more than one perspective.

The remaining claims are “dependent” claims. A dependent claim is usually identifiable by the introduction of “The apparatus/method of claim X”, “The apparatus/method of claims A to B”, “The apparatus/method of any preceding claim”. The dependent claims represent “fallback” positions which become important if an independent claim is found to be deprived of novelty or inventiveness. They cover an apparatus or a method including all of the features of the claims which are referred to and the additional feature of the dependent claim. They are narrower than the independent claims (because they introduce another feature which something must have). The dependent claims should include features that are important and would be valuable to protect, or in some cases relate to additional features that serve to clarify features of the independent claims. As Intellectual Property Offices charge fees for claims in excess of a certain number (25 with the UK IPO, 15 before the European Patent Office), the claims might not include every important feature, some features may only be found in the summary of invention (discussed below) for use as possible claim amendments in the future. Usually the highest priority is to include features which might make or break whether an idea is inventive, if the subject matter of other broader claims turns out to be known in the prior art.

If there are any further important distinguishing features which are not mentioned in the claims or the summary of invention, then you should point this out to your patent attorney.

Summary of Invention

The summary of invention section is relatively early in the document, immediately after the introduction, and expands upon the features of the claims and provide technical advantages for those features. For example, the summary of invention may provide examples of the features mentioned in the claims (e.g. ‘the fastener may be a screw or nail’) or may clarify what is meant by a particular term used in the claims. This section may appear somewhat repetitive of the claims and will likely include words which make it clear that the features are optional. This is normal and indeed is intentional, as it gives us flexibility and a variety of further fallback positions. You should check that the summary of invention includes realistic technical advantages of the features of your invention and that the features of your invention are sufficiently detailed. One function of the summary of invention is as a reservoir of possible claim amendments and so if there is a feature which you might want to introduce into the claims during examination to distinguish over prior art, you should make sure that it is set out in the summary of invention.

Description and Drawings

The description provides a description of one or more working embodiments of your invention. Whilst the description should be technically accurate, it does only set out examples and is not limiting, so do not be afraid to commit to precise examples as to how the invention could be carried. It is important that the description sets out an enabling disclosure, that is to say, sufficient information about the invention must be provide to enable a person skilled in the art to reproduce the invention without undue burden or inventive activity.

The description will usually refer to the drawings. The drawings are numbered and labelled with reference numerals to label important features of the drawings of your invention. You should check that all of the features mentioned in the claims are shown in the drawings and referred to in the description. The drawings should be black and white line drawings, though other types of drawings (e.g. photographic images, computer renderings) can be filed but the patent office may ask for formal drawings (i.e. conversions of the drawings into black and white) to be filed at a later date.

Abstract

The abstract is a short summary of your invention. It will usually include the features of some or all of the independent claims and may state the technical field of your invention. The abstract does not affect the scope of protection and cannot be used as basis for amendment of the application once it is filed. The abstract will be filed with reference to a figure number of one of the drawings which depicts the features of claim 1. In some jurisdictions, like the UK, the abstract can be filed up to 12 months after the filing date and so the abstract might not be included in the application as filed.

Author: Phoebe Hunter