Tuesday, 12 January 2010

T 129/08 – Together Yet Apart

This decision contains an interesting paragraph dealing with a problem that might interest drafters of patent applications concerning mechanical devices.

Claim 1 of the main request reads :

Internal combustion engine having a cylinder head and at least one camshaft (74) which is mounted on the latter and actuates corresponding gas exchange valves on the cylinder head in a manner driven by a crankshaft, a camshaft adjuster (76) being provided on the camshaft (74), which camshaft adjuster (76) rotates the camshaft (74) relative to the crankshaft by means of hydraulic pressure in order to change control times of the gas exchange valves, a feed apparatus for feeding hydraulic pressure to the camshaft adjuster (76) being provided and being configured as a separate component (10) from the cylinder head and having a ring (12,13) for each camshaft (74), […], characterized in that each ring (12,13) surrounds a section of the camshaft (74) and the respectively surrounded section of the camshaft (74) has two annular grooves (82,84) which are each aligned with a groove (38,42 or 62,60) of the corresponding ring (12,13), each groove/annular groove pair (38/82, 42/84) of a ring (12, 13) being connected via respective hydraulic pressure ducts (86,90) in the camshaft (74) to a hydraulic pressure chamber (88, 92) of the camshaft adjuster (76) which is arranged on this camshaft (74).

[…] It is undisputed that E2 discloses a combustion engine according to the preamble of Claim 1. This engine comprises […] a camshaft (2) and […] a camshaft adjuster (3), a feed apparatus for feeding hydraulic pressure to the camshaft adjuster being provided, which […] comprises a ring (23) for each camshaft […] [2.1] 

NB: Reference 23 of E2 refers to a borehole; the correct reference for the ring is 37.

[…] As far as the characterising portion of claim 1 is concerned, according to which each ring surrounds (umgreift) a portion of the camshaft, E2 undisputedly discloses (Fig. 1) that each ring (23) surrounds a portion of a ring part (27) which is connected with the camshaft so as to rotate therewith (drehfest).

The patent proprietors contest that this ring part is to be considered as belonging to the camshaft.

As a matter of fact, the patent proprietors are to be approved in that, when the engine of E2 is dismantled, the skilled person would distinguish between the “bare” camshaft (2, i.e. the shaft with its cam without the additional parts shown in Fig. 1) and the ring part (27), because these parts are then separated. However, the skilled person would not necessarily differentiate them when the engine is assembled, because then the ring part (27) is mounted so that it rotates therewith and is and axially undisplaceable (at least because of screw 26) manner on the “bare” camshaft (2) so that the ring part (27) and the “bare” camshaft (2) form a single construction unit. This construction unit consisting in the “bare” camshaft and the ring part can be designated as “camshaft”.

In other words, there is no clear borderline between pieces that are fixed to each other and which on one hand belong to the camshaft, and on the other hand do not belong to it (zwischen miteinander fest verbundenen Teilen, die einerseits der Nockenwelle zugehörig sind und andererseits der Nockenwelle nicht zugehörig sind), because such a borderline depends on the circumstances under which the camshaft is considered (dismantled, mounted in the engine, during dismantling, …).

Therefore, E2 discloses that each ring (23) surrounds a portion of the camshaft, i.e. the portion 34 of the ring part 27 belonging to the camshaft. [2.2]

[…] Claim 1 cannot be considered to be novel over E2. [2.4] 

I do not find this reasoning persuasive, because the claim is directed to an assembled engine and not to a set of engine parts. Therefore, the considerations concerning the engine when disassembled or when being disassembled do not really seem relevant. Either a piece is part of the camshaft or it is not. E2 rather suggests the ring part is not. The relevant question (which has not been discussed) appears to be whether the feature that the ring ‘surrounds’ (umgreift) the camshaft is still reproduced by a ring that surrounds a ring part that is fixed to the camshaft. Personally, I would say that it is, even though the German verb ‘umgreifen’ might suggest a more direct contact that its translation ‘surround’.

Anyway, even if novelty were acknowledged, there might be a good case for arguing that Claim 1 was not inventive over E2.

To read the whole decision (in German), click here.