Folding Attic Stairs Ltd v The Loft Stairs Company Ltd & Anor (Rev 1)

Patent claims must be construed purposively, by reading the claims in the context of the specification and asking what the skilled person would understand the patentee to mean. Words such as “preset” may impose a requirement of intentionality where the purpose of the selection is sufficiently clear. They are not necessarily meaningless or invalid for uncertainty.

A disclosure on private premises by a small, defined class of visitors does not automatically form part of the state of the art merely because the visitors were legally free to inspect and communicate what they saw. Information must ordinarily have been actually imparted to a person free to disclose it. A process claim is not anticipated unless the claimed process itself was disclosed, and obviousness must be assessed without hindsight.

The claimant manufactured folding attic stairs and owned a patent for a process of manufacturing them. The defendants manufactured competing stairs and were sued for patent infringement. They challenged the patent on the grounds of anticipation and obviousness, relying principally on the claimant’s earlier product, a newspaper photograph, and a test unit seen by an Irish Minister and a photographer during a factory visit.

The central issues were the meaning of the claim requirement that the inner frame’s side beams be spaced a “preset distance” from the outer frame, whether the relevant disclosures formed part of the state of the art, whether the claimed process was anticipated or obvious, and whether the defendants’ products infringed.

1. Construction. Claim 1 was a process claim directed to manufacturing folding stairways on a repeat basis. “Preset distance” meant a distance selected by the manufacturer, or by someone authorised by him, with the aim of accommodating different ceiling-opening widths while avoiding excessive bending or cranking of the support arms. A merely accidental spacing did not satisfy the claim. The construction gave the manufacturer reasonable certainty and did not require the court to decide whether an objectively excessive level of strain had occurred.
2. Intentionality may be a relevant feature of a patent claim. Nothing in the Patents Act 1977 or the European Patent Convention prohibited such a construction, and the claim was not, as such, a scheme or method for performing a mental act.
3. Validity. Old Stira was part of the state of the art but did not disclose the claimed manufacturing process. The process was neither anticipated nor obvious. The newspaper photograph did not disclose the essential arrangement or the purpose of varying the inner frame. The test unit likewise did not disclose the manufacturing concept and would not have led the skilled person to it without hindsight. Lundh was further removed from the claimed invention and did not anticipate or render it obvious.
4. There was no irrebuttable rule that information visible to visitors on private premises had been made available to the public. Where a small and defined class could inspect a prototype but had no relevant interest and there was no evidence that the information was actually perceived, the court could infer that it had not been made available. Even assuming sufficient disclosure, the test unit did not anticipate or render the process obvious.
5. Infringement and order. The defendants’ larger stairs infringed because the inner-frame arrangement was adopted for the same purpose as the patented process. The 22-inch version did not infringe because its support arms were attached directly to the ladder sides. Judgment was entered for the claimant, subject to that exception.