T 0023/86 (Computer-controlled switching device) of 25.8.1986

Summary of Facts and Submissions

I. The respondents are the proprietors of European Patent No. 0 036 417 based on an application filed on 26 September 1980. It has three claims, Claim 1 of which is as follows:

"A computer-controlled switching device for controlling power-switching elements such as relays, protective motor cut-outs or the like, for controlling equipment or installations, in which the computer is connected via an analog-digital converter to at least one sensor monitoring the current consumption of the equipment being monitored such as a motor, transformer or the like, calculates data according to a particular model and issues switching commands when certain preset values are exceeded or not reached, characterised in that the sensor or sensors responding to the magnetic field of the conductor(s) of the equipment being monitored are arranged on a board and each have a passage aligned with an opening provided in the housing, and in that the device has two boards electrically connected together by disengageable plug-type connections, one board carrying connecting terminals and the switching element controlled by the computer and where appropriate a mains or other voltage source, while the other carries the sensor and computer together with the analog-digital converters and the setting elements."

Claims 2 and 3 are dependent on Claim 1.

II. An opposition filed by the appellants against the patent was rejected by the Opposition Division in a decision delivered to the appellants on 20 December 1985.

III. In the appeal lodged on 17 January 1986 for which the fee was paid on time and the grounds submitted on 3 April 1986 the appellants proposed that the disputed patent be revoked in its entirety, asserting that: (a) The first four lines of Claim 1 were unclear, with the result that the claim confused the legal position. (b) DE-B-2 310 103 was not a suitable basis for the preamble to claim 1. (c) The general idea, deemed inventive by the Opposition Division, of two boards electrically connected together so as to be disengageable, one of which carries the light-current elements and the other the heavy-current elements, was not manifest, as the sensors were not light-current elements. (d) The subject-matter of DE-B-2 359 452 came close to that of the disputed patent and even had a technical advantage over it. (e) The idea of providing separate boards for certain components of a control system was known from DE-A-2 209 786, which suggested the subject-matter of the disputed patent. (f) Even if Claim 1 were to be more clearly stated, it would still not stand because its subject-matter lacked inventive step. (g) Claims 2 and 3 related only to obvious, purely constructional features.

IV. The respondents/patent proprietors ask that the appeal be rejected. They do not agree that Claim 1 is unclear and that its subject-matter is obvious from the demonstrated prior art. They also dispute that the device known from DE-B-2 359 452 is technically more advantageous than that of the disputed patent.

Reasons for the Decision

1. The appeal complies with Articles 106 to 108 and Rule 64 EPC and is therefore admissible.

2.It should first be pointed out that Article 84, which states that claims must be clear, is an EPC requirement relating to applications that under Article 102(3) must also be taken into account in opposition proceedings whenever the patent proprietor makes any amendments. Opposition cannot however be based on the assertion that a claim is not clear as required by Art. 84. The only points to be considered in opposition proceedings are: whether the patent (as a whole) discloses the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art (Art. 100(b)), whether the subject-matter of a claim as understood from its wording, if necessary using the description and drawings in accordance with Article 69(1), second sentence, by a person skilled in the art helped by his technical knowledge is patentable (Article 100(a)) and whether this subject-matter does not extend beyond the content of the application as filed (Article 100(c)). There is thus no reason to consider whether the relevant claim on its own, without reference to the description and drawings and without further reflection, raises doubts as to its meaning in the mind of a person skilled in the art. Opposition proceedings are not a continuation of the examination proceedings involving third parties but, like revocation proceedings, serve as a substantive legal test of whether the patent still stands in the light of facts emerging after it has been granted (cf. Decision Gr 01/84, point 9 - OJ EPO 10/1985, p. 304).

In the present case, incidentally, Claim 1 is not unclear as the appellants contend. In the claim of the patent as granted, although in the statement of the invention's field of application ("for controlling ..."), the words "power switching elements" are followed by "such as relays, protective motor cut-outs or the like", these examples do not render the claim any less clear. All they do on the one hand is define in more detail a mere statement of purpose ("for controlling ...") and not for instance a feature characterising the invention, while on the other they make it quite clear to the person skilled in the art from the outset without any need even to read the description that the term "power switching elements" is used to mean an electromechanical or electronic component which in response to a control signal is able to open or close electric power circuits. While the examples given might be superfluous, they do not notably detract either from the clearness of the claim or the legal position. Incidentally, the same also applies to the words "such as a motor, transformer or the like" as examples of the equipment to be monitored, which the appellants do not criticise.

3.The subject-matter of Claim 1 is novel.

3.1 DE-B-2 310 103 discloses a switching device with all the features of the preamble to Claim 1. It does not however say anything about the mechanical structure and therefore contains none of the characterising features of that claim.

3.2 DE-B-2 359 452 discloses a housing with means for monitoring a current passing along conductors, i.e. a switching device. This device has sensors 102, each with a passage 103, which respond to the magnetic field of the conductor leading to the equipment to be monitored. It cannot however be deduced from this document whether the device is computer-controlled and has analog-digital converters. Nor is it evident that the sensors 102 are arranged on a board. Also, the passages 103 are located in openings 101 in two side covers 34, so that they do not align with the openings in the housing. Moreover, the housing frames 31, which may be compared to the housing in the disputed patent, each contain only one board. All the features stated in column 4, lines 50 to 60 of the disputed patent are therefore lacking.

3.3 DE-A-2 209 786 discloses a housing to contain electrical components which has several electrically interconnected boards. In contrast to those of the disputed patent, these boards carry an amplifier, a relay module, a timer module and a mains supply unit. The housing, therefore, does not contain a computer-controlled switching device with analog-digital converter and sensor and hence lacks all the features of the preamble to Claim 1. In addition, the electrical connection between the boards is effected by soldering (see page 4, lines 13 to 16) and not by means of a plug-and-socket system. Nor do the boards carry sensors, computers, or switching elements. The features stated in Claim 1, column 5, lines 26 to 31 and 34 to 42 are therefore lacking.

3.4 DE-A-2 736 546, which is not discussed by the appellants, is not closer to the subject-matter of the disputed patent and can therefore be disregarded in considering novelty.

3.5 DE-A-2 310 103 and DE-A-2 359 452 mentioned in the European search report are identical in content to the corresponding published patent specifications.

4.The subject-matter of Claim 1 is based on inventive step.

4.1 The preamble of Claim 1 starts from the state of the art as known from DE-B-2 310 103. The appellants contend that the latter was not a suitable basis for this purpose since it disclosed only the manner of operation of a switching device as does the preamble of Claim 1 but did not disclose anything about the mechanical construction of the device, which is precisely what the disputed patent is concerned with. The Board of Appeal cannot agree with this view. Firstly, the preamble of Claim 1 contains not only references to function, such as "calculates data" or "issues switching commands", but also information relating to the arrangement of individual components within the circuit ("the computer is connected via an analog-digital converter to ... one sensor ..."). Secondly, the references to functions here help one understand how the various components interact. This interaction of the various components, however, is also a factor determining the mechanical structure of the device. In the absence of any closer state of the art, it is therefore right to start out from DE-B-2 310 103 which concentrates only on the manner of operation of a similar device.

4.2 Starting from this premise, the problem the subject-matter of the disputed patent sets out to solve is to design a switching device of this kind that is easy to assemble and of simple construction (column 1, lines 23 to 26 and 43 to 53 of the disputed patent) and enables components carrying only light current to be separated from those which also carry heavy current (column 2, lines 13 to 15).

4.3 This is achieved by the features stated in the characterising part of the claim. While this is quite obvious as regards the first two aims stated - simplicity of assembly and construction - since a disengageable plug-and-socket type connection is easier to assemble than soldered ones and the arrangement on boards makes for particular simplicity of construction, it is also true of the last-mentioned aim. However, the Board cannot agree with the appellants that the sensors 18 are not light-current elements. On the contrary, it is evident from column 3, lines 25 to 29 of the description that the sensors themselves carry only light current. Heavy current flows only through the conductors monitored by these sensors. This becomes particularly clear when in column 1, lines 54 and 55, reference is made to Hall generators being used as sensors. 4.4 Nor is it possible, moreover, to agree with the appellants' contention that DE-B-2 359 452 comes very close to the subject-matter of the disputed patent simply because this also refers to circuit boards carrying electrical components likewise accommodated in housings. It cannot be deduced from this patent where and how the passages 102 are made in the housing. The appellants' assumptions that the components responding to the magnetic field in the known arrangement are located on the circuit boards and that the latter are brought into contact with the outer surfaces of the connecting lugs of passage 102, or could be pushed into these, might well suggest themselves to the person skilled in the art having prior knowledge of the disputed patent, but not to one without such knowledge. For the rest, in the case of the disputed patent the sensors are, for the sake of simplicity, arranged on the board itself and are not just connected to it by means of connecting lugs. If, as the appellants maintain, a person skilled in the art would see a technical advantage in this separate arrangement, this would if anything prevent him from arranging the sensors directly on the board instead of using connecting lugs. Nor, moreover, does DE-B-2 359 452 lead to the subject-matter of the disputed patent from the point of view of the type of problem stated since the known arrangement is intended to allow the manufacture of housings of different sizes for a variety of purposes whereas in the disputed patent a single housing is used for one particular purpose.

4.5 DE-A-2 209 786 likewise does not really suggest the subject-matter of the disputed patent. On the one hand, in the arrangement it shows the electrical connections between the individual boards to be obtained by soldering, which as far as construction and assembly is concerned is undoubtedly more complicated than in the case of the plug-and-socket connections used in the arrangement of the disputed patent. On the other hand, the distribution of different sub-assemblies such as amplifier, power-supply, relay and timer modules, each on one of several boards, still does not suggest dividing light-current and heavy-current elements between just two boards, which the Opposition Division rightly saw as the crux of the invention.

4.6 Moreover, DE-A-2 736 546 does not, as does the disputed patent, give any indication that the light-current elements only might be located on one of the two disengageably connected boards and the heavy-current elements only on the other.

4.7 Set the task of designing a computer-controlled switching device that is of simple construction and easy to assemble and in which any influencing of sensitive light-current components by heavy- current components, especially a power switch, is avoided or at least reduced, a person skilled in the art would not therefore be guided by any of the citations towards the solution claimed.

5.Claims 2 and 3 refer back to Claim 1 and describe advantageous embodiments of the device as claimed in Claim 1. They therefore also stand.

6.In the original German version of Claim 2 (column 5, line 3) a printer's error has resulted in the word "Gebäudes" (building) appearing instead of the "Gehäuses" (housing) contained in the document used as the basis for grant. Correction of the patent specification is unnecessary, however, given the obviousness of the error.

ORDER

For these reasons, it is decided that:

The appeal is rejected.