Claim Language in Patent Applications

A patent is a contract between the state and an inventor; and care must be exercised to see that both are treated fairly. If this policy is interpreted to limit the scope of the inventor’s claims, he would not receive adequate legal protection for the contribution he is making to the promotion of science and technology. On the contrary, further experimentation by others is discouraged if the patent claims are made very road and there is no method of checking liberal interpretation of claims leading to monopolization of the art unfairly. This in turn would violate the general purpose the patent laws, which are primarily designed to promote the progress of science rather than to reward the inventor.

An invention is protected through claims in a patent which precisely define what the invention is. The claims and the claims alone construct a fence around the patented invention to avoid its unlawful use. It may be noted that legal protection is awarded only to what is included in the claims and the matted not included is open to public for creating new inventions. It is necessary to understand the meaning and scope of a patent’s claims in order to determine whether a proposed course of action would constitute an infringement or whether it would enlarge the scope so much that the interest of the state is jeopardised. As a great deal in decision making would depend on how one constructs claims, the language of claims assumes a very important place.

A factor which may affect the interpretation of patent claims is prior judicial definition of terms or expression appearing in the claims. Where the terminology of a patent claims may be susceptible of various interpretation having more than one definite meaning, it may be found that courts have been confronted, in earlier cases, with the problem of interpreting the same or similar language. In addition, the courts have also developed over the years a number of general rules for interpretation of claims. Unfortunately, the rules may vary from one court to another court. The general rule, however, is that patent claims, unless limited by patent office proceedings or by prior art, or by judicial determination, are to be construed literally. It is the opinion of some courts that a patentee is bound by the language and terms of his claims.

One of the interesting examples relates to the use of words ‘comprises’ and ‘consists’ in patent claims. Two words are not different in their meanings according to many dictionaries namely Chambers, Oxford, Webster ad Collins; and both convey the meanings to contain/include/constitute or to be composed of and to be made up of. However, in the patent practice these words have different interpretations. ‘Comprising’ denotes a very broad and open claim which can be interpreted to include unspecified ingredients, even in major amounts. ‘Consisting’ of would generally imply a narrow claim not allowing inclusion of materials other than those already stated in the claims. Let us take an example. Two claims are stated in the following manner;

A writing instrument, which comprises a pencil and clip for holding the apparatus in a product, said clip being attached to said pencil.

This claim covers all writing instruments which have at least a pencil and a clip. A writing instrument containing other elements , such as an eraser attached to the pencil will be covered under this claim. The claim has become very broad by the use of the word ‘comprises’.

A pharmaceutical composition which consists of the anti-malarial agent Y and a pharmaceutically acceptable carrier.

In this case, the claim covers compositions which contain only anti-malarial agent Y and the carrier and nothing else. A composition which contains any additional ingredients does not infringe the claim.

There are many other words which need to be carefully used.

"Preferably": The word suggests that the component or condition to which the word relates is optional, not essential or not necessarily effective in changing the result to a degree constituting a different of kind. In the absence supporting data, ‘preferably’ may destroy the criticality of the feature. For that reason, it is sometime desirable and possible to replace the word, for example, by change of "and preferably at a temperature of …" to "and for best results (or best yield, increased water resistance of the product; or rate of curing, etc.), at a temperature of ……

"May": The word "may "carries with it also the meaning "may not". The word "can" is stronger and at times a good replacement. "May", it should be added, is much used, no doubt properly but never in claims.

NB : Patent attorneys and to some extent patent agents are equipped to use words, phrases and terms appropriately in the right manner acceptable to patent offices and courts. It is advisable to consult a patent attorney for drafting of claims. If you have better information on the use of some words etc., you may guide the attorney. A team work would pay in the end.