It is not often that corkscrews are discussed in the British High Court, although I am sure that their Lordships have often retired to use them after many a hard case. This recent Financial Times report however sets a new precedent.

The article relates to a patent case between Hallen Co. who manufacture the Screwpull and Brabantia who are selling an excellent modern corkscrew using the same Screwpull principle. Their corkscrew has a long PTFE coated worm but with the addition of a very clever plastic barrel which facilitates the removal of the cork from the worm. I own both of these modern screws and the Brabantia is superior.

I am no patent expert, but through my work I do have passable knowledge of patent procedures and can perhaps help my fellow addicts work their way through the court's ruling.

I do not know the background to the case, but I strongly suspect that Hallen sued Brabantia for breach of the Screwpull patent in that Brabantia copied the long PTFE coated worm. Brabantia did not defend their position, but interestingly, actually challenged the validity of Hallen's patent, in that it was not a true innovation but was obvious.

Patents are funny things. They ostensibly give the inventor commercial protection against copies, but they can always be challenged. They are only valid for 20 years, or until they are successfully challenged. Patents are only as strong as their contents, and in the way in which they are written. Indeed most commercially successful patents are never challenged since they are so strong.

So, Brabantia said to Hallen - you can't sue us because your patent is not valid - the so called invention was obvious. In all patent cases the interpretation of what is obvious, is always a moot point - what is obvious to one "skilled technician" is not necessarily obvious to another.

The Financial Times article refers to two trials. The initial one was under Justice Aldous who found the Hallen patent to be invalid since the "invention" was obvious. Hallen appealed that Aldous' ruling was wrong, but, his decision was upheld at the subsequent hearing under Justice Slade.

Hallen lost - the Screwpull patent is invalid with respect to PTFE coated worms.

The "obvious" ruling was based on the following pieces of general knowledge which were available in July 1978, the date that the Screwpull patent was filed.

1) Self-puller corkscrews were known from the 19th century and indeed Watney and Babbidge describe Chinnock as the "father of the self-puller" (p. 87-89) after his 1862 patent. Other, later examples are the Surprise (1884) and the Walker bell-cap (1893).

2) PTFE was well known as a friction reducing material. It was not however common knowledge that corkscrews were coated with a friction reducing material, but, if anyone had wanted to, they would have used PTFE.

It was therefore deemed as obvious that any skilled man who wished to market an improved self-puller would coat the helix with a friction reducing material such as PTFE. Potential commercialisation did not come into the argument.

Personally, I feel that Hallen and Screwpull were hard done by and that this was a harsh ruling. The Screwpull was a giant leap for mankind, and although in retrospect, it may have seemed very obvious to coat a helix with PTFE, Herbert Allen was the first to realise its immense implications and produced the near-perfect corkscrew (see W and B page 146).