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Phrases such as ‘for use’ and ‘when used’ are construed to inherently impart an element of conditionality, signalling that the true scope of the claim is likely to be different from a superficial reading of the words.

This section provides guidance on interpreting claims that use conditional wording.

As always, the words used in a claim must always be construed in the context of that claim and the specification.

‘for’, ‘for use in', ‘used to‘, ‘used for‘, etc.

Generally, in claims directed to a product or apparatus, these terms limit the claim only to the extent that it must be suitable for the specified purpose.

For example, a claim to a ‘hook for a crane‘ implies that the hook is of a particular structural character which makes it quite distinct from a fishhook.

However, claims in the form ‘An apparatus for [for use in/used to/used for etc. …]‘ merely indicate the environment the apparatus is intended to be used in; they do not limit the apparatus to use solely in that environment (Thurston Catton’s Application [1978] AOJP 3666). Consequently, a claim of this form is construed to be a claim to the apparatus per se, albeit having a functional capability in the specified environment.

Similarly, a claim to a substance or composition for a particular use would normally be construed as relating to the substance or composition per se (Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius & Bruning’s Application [1964] AOJP 1483).

While the above sets out the usual interpretation, sometimes the context of the claim clearly mandates a different interpretation. This is the case with Swiss claims, where the formulaic structure of the claim exists for a particular purpose.

Therefore, if an applicant argues that the terms 'for', 'for use in' etc. are to be interpreted differently from the ‘typical’ interpretation outlined above, this argument needs to be supported by persuasive reasoning.

Generally, method or process claims using 'words of purpose' are construed as being restricted to that purpose. The process steps in the method results in imparting the restriction​​​​​​​. For example, a claim defining ‘A method for producing X‘ is limited to a method that would result in the production of X. However, there may be exceptions to that construction of method claims or process claims, depending upon the facts of the case (CSL Limited v Pharmacia & Upjohn AB (2000) APO 58).

‘when used‘, ‘whenever used‘, 'use of'

The terms ‘when used’ and ‘whenever used’ have the effect of limiting the scope of a claim to a particular application, environment or timing. Thus, a claim to something ‘when used‘ in a process, is normally construed as a disguised process claim. Similarly, a claim in the form ‘Use of X for…‘ or ‘Use of X to…‘ is normally construed as a process claim.

This construction was accepted in Wellcome v Commissioner of Patents 1A IPR 261 at page 266:

"... there is no distinction between the claim to the process and the claim to the substance when the substance claim is limited to its use in the process."

There may be circumstances where a ‘when used‘ or ‘use of‘ claim defines something per se (rather than a process) due to the specific facts of the case. However, this exception to the normal interpretation should only be adopted when it is clearly required by the wording of the claim. Examples are:

  • A claim to ‘A combination of compounds A and B whereby the said combination produces a synergistic effect when used in the treatment of tumours‘ defines a composition of A and B capable of producing a synergistic effect; and

  • A claim to ‘Compound X when used to stabilise compound Y‘ is equivalent to a claim to a composition of X and Y.

Note: Where a claim is directed to a product, apparatus or substance, but has a described use without the phrase “when used” or “whenever used” (particularly in the claim preamble), this should be taken as a suitability limitation only, unless otherwise indicated.

A claim to an apparatus ‘for carrying out’ a process was held to be equivalent to a claim to the apparatus per se in L’Aire Liquide Societe Anonyme pour L’Etude et L’Exploitation des Precedes George Claude (1932) 49 RPC 428. However, amendment of the claim to ‘An apparatus when used for carrying out the process’ restricted the claim to the apparatus when used in a particular manner.

Special considerations

Certain types of use claims raise special issues, as shown in the following examples.

‘Use of compound X for combating diseases’

If the description only discloses that compound X is useful for treating a specific disease (for example, cardiac arrhythmia), then the claim will be objectionable under s.40(2)(a) (clear and complete enough disclosure) and/or s.40(3) (clear, succinct and supported). (See Pharmaceutical inventions and methods of treatment and Useful (specific, substantial, and credible use)).

‘Use of compound X for the treatment of cardiac arrhythmia’

Although the claim encompasses medical treatment of human beings, no objection is to be taken on that basis alone (see Treatment of Human Beings).

However, if the invention relates to another use (a second pharmaceutical indication) of compound X, the examiner will need to consider novelty or inventive step issues in the light of any use disclosed in the prior art (see ‘New Uses’).

‘Use of compound X for the preparation of medicament Y for treatment of disease/condition Z’

Such claims, and certain variations along similar lines, are known as ‘Swiss claims‘ (see Swiss claims​​​​​​​).

Amended Reasons

Amended Reason Date Amended

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