Which of the following transitional clauses is an example of open-ended claim language in the context of a patent:
b) consisting of
The answer is a). Comprising leaves the door open – the invention encompasses the specified element(s), but could also encompass more. Consisting of, by comparison, limits the scope of the claim to the specified element(s) and nothing else.
Patent language is full of subtlety and nuance, layered on top of technical detail. Patent applications are even said to be “the most difficult legal instruments to draw with accuracy.” (1) When even transitional clauses are terms with significant legal implications, it’s important to do your homework, and question everything.
Remember – the devil is in the details.
Faber on Mechanics of Patent Claim Drafting (pricey, so check your local library!)
Espacenet – the European Patent Office’s searchable database
LexisNexis … offers patent research resources and even offers a free trial of their Patent Optimizer application that can check for specific errors – including terms and phrases.
IPWatchdog offers articles and webinars on patent drafting
(1) Laitram Corp. v. Cambridge Wire Cloth Co., 863 F.2d 855, 856-57 (Fed Cir. 1988).