The common general knowledge
13.Mr Mace explained that at the priority date care was taken by the plumber to ensure that the water pipes emerging from the wall were in the correct position to be joined later to the inlets of the shower. Once the pipes were in place the wall was finished, probably by another tradesperson such as a plasterer or a tiler. It was important that during the plastering and tiling the pipes remained in position. There were alternative means to do this such as using plastic clips around the pipes which were screwed to the wall. When the plasterer or tiler had completed their job the plumber returned to attach the pipes to the shower inlets. 14.Both experts stated that UK plumbers are conservative when it comes to practices in the trade. Though not a major factor, I take this to mean the skilled person would not have had an enthusiasm for abandoning his or her established way of doing things. 15.On page 1 the Patent refers to a mounting plate which, the Patent says, was commonly used in continental Europe. I will call this the ‘Continental Plate’. Both counsel submitted that only the common general knowledge in the UK was relevant (I discussed this in Regen Lab SA v Estar Medical Ltd [2019] EWHC 63 (Pat) at [44]-[50]) and that the Continental Plate was not common general knowledge in this country. Nonetheless the discussion of the Continental Plate in the Patent would play a significant role in the reader’s understanding of the invention claimed. The Patent 16. After a short introduction to the invention, the specification introduces the Continental Plate on pages 1-2: “Particularly where the appliance has a pair of inlet fittings, it is known to use a mounting plate which includes integral fittings which are joined to pipe parts which terminate in the fittings. Thus an appliance may be installed later by joining the pair of inlet fittings of the appliance to the fittings integrally provided by the mounting plate. Such a system is commonly used in continental Europe.” 17. The advantages and disadvantages of the Continental Plate are explained: “The use of a mounting plate as described is advantageous particularly where the appliance has a pair of inlet fittings as the spacing between the pipe parts can be set by the pipe parts being joined to the integral fittings of the mounting plate, and moreover, by having a mounting plate secured relative to the wall, a rigid mounting is provided for the appliance. However, the integral fittings of the mounting plate each provide a female connecting part for receiving a pipe part end, and a male or female connecting part for joining with an inlet fitting of the appliance. The female connecting part faces inwardly of the wall on which it is desired to install the appliance, and thus the joints between fittings and pipe parts have to be made prior to securing the mounting plate on the wall. After the pipe parts and integral fittings have been joined, and the mounting plate is secured relative to the wall, the joint is inaccessible.” 18.The specification moves on to describe the usual practice in the UK at the priority date: “In the UK, the use of such mounting plates is uncommon. This is because the practice in the UK is make joints directly between the outwardly projecting pipe parts and inlet fittings of the appliance.” 19.There follows a description of the invention, the claim 1 method, which is said to combine the advantages of the usual UK practice with the advantages of the Continental Plate: “Thus the invention enables advantages of the known system to be realised, namely that the mounting member can provide a rigid mounting for the appliance and help set the distance between a pair of pipe parts where the appliance has a pair of inlet fittings, whilst enabling joints to be made directly between the pipe part or parts and the inlet fitting or fittings.” 20.A point to be noted is that the direct joining of pipe and inlet fitting referred to is between the pipe and the inlet fitting of the appliance. It is that joint which advantageously remains accessible using the claim 1 method. 21.The description returns to the advantages of the invention on page 3, one of which, mentioned again, is the accessibility of the joint between the pipe and the inlet fitting of the appliance: “By virtue of the invention, the pipe part or parts is/are prevented from moving axially and thus the making of joints between the pipe part or parts and the inlet fitting or fittings can be made less difficult. Moreover there is no inaccessible joint with the pipe part.” 22.At the trial argument was directed just to claim 1 so I need consider only that claim.