T 0910/12 - Public prior use

EPO T 0910/12

For the decision, click here

Key points

• This decision concerns possibly novelty-destroying public prior use. However, the service manual provided as evidence of the public prior use (together with invoices) does not disclose all features of the claim. Hence, the claim is held to be novel over the public prior use.

Reasons for the Decision

1. The appeal is admissible.

2. Background of the invention

The patent relates to materials handling device, such as a fork lift truck, see specification, paragraph [0002]. Typically such a device has a carriage assembly, e.g. for moving forks vertically. The assembly is raised by pumping hydraulic fluid into a cylinder and lowered by releasing the fluid. Conventionally, a mechanical safety valve at the base of the cylinder, called a velocity fuse, shuts off flow out of the cylinder when the lowering speed exceeds a fixed limit.

A disadvantage with this arrangement is that a driver might sometimes want to exceed the lowering speed-limit to improve their productivity, and indeed could safely do so, but the velocity fuse prevents this, see specification column 1, lines 34 to 40.

To overcome this, the invention of claim 1 provides an electronically controlled valve to carry out the function of the velocity fuse. A control structure closes the valve in the event of an unintended descent of a carriage assembly in excess of a commanded speed, see also specification, paragraph [0009]. This allows the driver to execute intended descents, even at high speed, whilst unintended descents at speeds exceeding a command speed are prevented, paragraph [0010].

3. Main request, claim 1 as granted

3.1 Novelty with respect to alleged prior use of a combitruck C15, D1 and D2

3.1.1 The decision found that a handling device known as Victor C15 combitruck was made available to the public by prior use before the priority date of the patent, and that this prior use implied document D2 to be prior art in its own right, decision point 3. Furthermore, the decision found that both the prior use of the C15 truck and D2 itself rendered the subject matter of claim 1 as granted not new, see decision point 5.

3.1.2 The appellant has argued that, even if they had been made available to the public, neither alleged disclosure would take away the novelty of the subject matter of granted claim 1.

3.1.3 D1 relates to the commercial background of the alleged prior use, but does not disclose technical information. Thus the only evidence that could shed light on the technical features of the C15 truck is D2. Without prejudice to the questions as to whether or not the information contained in D2 was rendered public prior to the priority date of the patent, the Board will first consider whether the public availability of the information contained in D2 would take away the novelty of the invention as claimed in claim 1.

3.1.4 D2 comprises extracts of a service manual for the Vector C15 truck. It is common ground that D2 shows the features of the preamble of claim 1.

That D2 concerns a materials handling vehicle with a base and a carriage assembly (e.g. the forks or driver cabin) movable relative to the base can be seen from the figure on the cover page of D2. The hydraulic system for lifting and lowering the cabin is shown on page 14-8, figure 14.2.5. A cylinder, e.g. the left-hand cylinder moves the cabin (figure title) relative to the base. The figure further shows a hydraulic system to supply the cylinder with fluid, pressurised by a pump P1. The hydraulic system comprises an electronically controlled valve, Y21 coupled to the left cylinder. The latter features are duplicated for a right-hand cylinder with associated electronic valve Y29.

3.1.5 For D2 to take away the novelty of the subject matter of claim 1, it would also have to disclose the safety arrangement defined in the characterising part of claim 1, that is a control structure to control the operation of the valve such that the valve is closed in the event of an unintended descent of a carriage assembly in excess of a commanded speed.

The Board interprets the feature to mean that the valve closing event is triggered by the actual speed exceeding the commanded speed. Such a descent, being contrary to what has been commanded, is an unintended descent. Thus the triggering event is not a descent above a fixed maximum speed, as is the case for a velocity fuse valve, but one exceeding the commanded speed, which may vary. Nothing in the specification suggests a different interpretation. On the contrary, the description (specification column 8, lines 18 to 32) confirms that the triggering event "unintended descent in excess of a commanded speed" means the [actual] descent speed is greater than commanded speed, with or without a certain tolerance.

3.1.6 D2 contains no explicit description of such a safety arrangement, nor has this been argued. The Board therefore needs to consider whether it is implicitly shown in D2.

The jurisprudence relevant to implicit disclosure of features is reviewed in the Case Law of the Boards of Appeal, 7th edition, 2013 (CLBA), I.C.3.3, and the decisions cited therein. As with explicit disclosures, the standard applied is the direct and unambiguous disclosure of a feature. In this context "implicit disclosure" means disclosure which any person skilled in the art would objectively consider as necessarily implied in the explicit content.

3.1.7 Normal cabin lowering is described on page 13-122, "Cabin lowering". The operator can select one of two lowering speeds. The motor M3 associated with the pump P1 then operates in a regenerative mode. Motor speed is monitored by a sensor U12 and communicated to the main computer unit, MCU. The MCU maintains a selected lowering speed irrespective of the load. However the claimed feature does not relate to normal lowering but to abnormal situations, namely in the case of an unintended descent of the carriage.

How abnormal lowering operation is monitored for malfunction is described on page 13-123 under the heading "Safety monitoring". As in the normal operating mode, pulse transducer U12 monitors M3's motor speed (point 5). The pump motor speed is monitored in relation to expected lowering speed (point 7). If a fault occurs the truck generates an error code and cabin lowering is blocked.

No explanation is given as to what is meant by the expected lowering speed. It could indeed mean the lowering speed commanded by the operator, as claimed. However the Board holds that another plausible interpretation is that, in the context of fault monitoring, it means the maximum lowering speed deemed safe. In other words expected lowering speed in the sense of what speed is expected to be safe. Thus the safety monitoring described in point 7 could involve monitoring lowering speed in relation to a maximum safe speed that is not necessarily the speed commanded by the operator.

Turning now to the error codes referred to on page 13-123, these are listed on page 13-221. Only one, alarm 4:100, mentions the lowering speed, namely in its description; "the lowering speed is too high". No explanation is given as to what speeds are too high. Although it could mean the actual speed is higher than the commanded speed, bearing in mind that this relates to safety monitoring, the Board holds that it could also mean that measured speed is higher than a maximum safe speed.

From the above the Board concludes that there is no direct and unambiguous disclosure that the truck described in D2 monitors for the event of an unintended descent of a carriage assembly in excess of commanded speed as required by claim 1. As explained above it could, for example, monitor for the event of an unintended descent of a carriage assembly in excess of a maximum speed expected to be safe.

3.1.8 Furthermore, the Board holds that there is also no direct and unambiguous disclosure in D2 of the valve Y21 or Y29 being closed in the event of an unintended descent of the carriage.

As mentioned above, in the cabin lowering system safety monitoring section (page 13-123), D2 states that, in the event of a fault, cabin lowering is blocked. Likewise, for the alarm 4:100, "lowering speed is too high", cabin lowering is said to be blocked (see note on page 13-221). Those parts of the Vector C15 service manual filed as D2 are however silent as to how blocking is achieved.

The decision considered that blocking implied controlling operation of the electronically controlled valves Y21 and Y29 to close, that is to move into the non-return valve position as shown in figure 14.2.5, page 14-8. The decision argued that this first option could be expected with a high probability and that the alternative option of stopping lowering by blocking the pump motor would not be legal.

Leaving aside the question of legality of the latter option, and keeping in mind the direct and unambiguous standard for assessing implicit disclosure, the Board holds that the former option is not the only possible way of stopping cabin lowering. As the appellant has argued, cabin lowering could for example also be achieved by applying a mechanical brake, independent of the hydraulic system.

In summary, the Board holds that D2 does not unequivocable disclose controlling the operation of the electronically controlled valve Y21 (or Y29) to close in the event of an unintended descent of a carriage assembly, let alone disclosure of doing so in the event of (or even monitoring for) an unintended descent of a carriage assembly in excess of commanded speed.

3.1.9 From the above, the Board concludes that there is no direct and unambiguous disclosure in D2 of the characterising feature of claim 1. Therefore the subject matter of claim 1 differs from D2 in respect of this feature and neither D2 itself nor the alleged prior use of the Vector C15 truck described therein would take away the novelty of the invention defined in claim 1. The questions as to whether or not the information contained in D2 was rendered public prior to the priority date of the patent, either by use of the Vector C15 truck or by making D2 itself public, are therefore moot.

3.2 The only reason given in the decision for not allowing maintenance of the patent as granted was lack of novelty of the subject matter of claim 1 with respect to the alleged prior use/prior disclosures based on D1 and D2. However, the notice of opposition also challenged novelty of claim 1 vis-à-vis documents D5 and D6 respectively and lack of inventive step vis-à-vis D7. The respondent has maintained this position in appeal.

In accordance with Article 111(1) EPC, second sentence, the Board of Appeal may either exercise any power within the competence of the department which was responsible for the decision appealed or remit the case to that department for further prosecution. In the interest of overall procedural efficiency, the Board proposed dealing with the remaining novelty and inventive step issues (see communication of 11 May 2015, point 4). As neither objected to this course of action, the Board decided not to remit the case to the first instance but to deal with them itself during the oral proceedings.

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3.6 In summary, without prejudice to the questions as to whether or not the subject matter described in D2 and D5 is proven prior art, the Board holds that the subject matter of claim 1 as granted is new and involves an inventive step and thus meets the requirements of Article 52(1) with 54(1) and with Article 56 EPC respectively.

4. Further independent claims 18 and 24 of the main request

Independent claims 18 and 24 have the same wording as claims 17 and 23 respectively in the version of the patent held allowable by the opposition division. In the interlocutory decision the opposition division held that their subject-matter was inventive, so that therefore this sole opposition ground raised against these claims did not prejudice their maintenance unamended. Due to the principle of prohibition of reformatio in peius, see G 9/92 (OJ 1994, 875) and G 4/93 (OJ 1993, 478) the Board sees itself barred from reviewing that part of the decision that in effect upholds some of independent claims as granted and against which the appeal by the proprietor as sole appellant is not directed, see also CLBA IV.E.3.1, case e) and T 856/92, point 2 of the reasons, cited therein.

5. The respondent-opponent has not challenged the decision's positive finding regarding the opposition ground of insufficiency, nor does the Board see any compelling reason to do so. It concludes that none of the opposition grounds raised against the patent prejudice its maintenance as granted, Article 101(2) EPC, second sentence.