Competing analyses
116 Mr Catterns contends that the Miller tripod operates by a different principle to that described and claimed in the patent. It does not operate by way of a connection between the two fixing means by a coupling/actuating member which couples and actuates both fixing means. On his analysis, the lower fixing lever of a conventional tripod has been relocated so that the same advantage as that described in the patent is obtained by locating the lower fixing lever close enough to the upper fixing lever to enable both levers to be operated simultaneously.
117 Mr Nicholas contends that 'if claim 1 is sensibly construed' the torsion rod need not actuate both the upper and lower fixing means. In written submissions in reply, Mr Nicholas expanded on the description of the inventive step as residing 'in the appreciation that the distance between the two crossbars in the prior art remains equal with the consequence that a coupling/actuating bar can be attached in order to operate two fixing locations simultaneously via the bar and the associated lever'. That is, the presence of the coupling/actuating member causes the first and second fixing means to operate in unison when the clamping lever(s) are engaged. The torsion bar actuates the second fixing means at the same time as the first fixing means is actuated by the clamping lever. In this way, Mr Nicholas contends, the lever is "operatively associated" with the coupling/actuating member as required by the claim. It is the presence of the coupling/actuating bar that enables the upper and lower clamping mechanisms to operate in unison.
118 Mr Nicholas submits that the proposition by Mr Catterns that the torsion rod in the Miller tripod plays no part in the operation of the first fixing means is wrong because, he says, the torsion rod enables the first and second fixing means to operate in unison when the levers are operated simultaneously. That, he says, is the inventive step.
119 Mr Nicholas disputes the assertion that the Miller tripod operates on a different principle to that of the patent. The common principle he proposes is an appreciation that the distance between the two crossbars remains equal and that a torsion rod is utilised in order to operate the two fixing locations simultaneously.
120 Mr Nicholas submits that a mechanism which involves a clamp which itself actuates the first fixing means directly and which remotely actuates the second fixing means via a torsion bar is within claim 1. Mr Nicholas concedes that, in the further or preferred embodiment in the specification, the torsion rod does not apply torque to the first fixing means; indeed he relies upon this to support his submission. As he points out, figures 4a and 4b show that the clamping lever is directly connected to the eccentric which in turn pulls on the tie rod. As Mr Nicholas put it, the 'simple reason' is that the torsion rod 'has no role to play in the actuation of the upper clamping mechanism' of the patent. Mr Nicholas relies upon the description of the further embodiment to support his construction of claim 1. He refers to the evidence of Professor Wightley and points out that, otherwise, the preferred embodiment depicted in the drawings is outside the claims.
121 In relying on figures 4a and 4b, Mr Nicholas does not make reference to figure 1a and the language of the rest of the specification.
122 The substance of Mr Nicholas' submission on this point is that, accepting the evidence of Professor Wightley over that of Dr Stark, the description of the preferred embodiment and the drawings are of a tripod in which the torsion rod, the coupling/actuating member, has no role to play in the actuation of the upper clamping mechanism. This should, he says, be taken into account in construing the expression "coupling/actuating member" as, otherwise, the preferred embodiment is outside the claim. Mr Nicholas submits that a requirement that the coupling/actuating member does play a role in the actuation of the upper clamping mechanism 'does not find support in the language of the claim' but he does not specifically deal with the language of integer 18.
123 Mr Catterns submits that a single embodiment is described. His explanation for the apparent differences between figure 1a on the one hand and figures 1b and 4a and 4b on the other is that, in the latter, the eccentric is located on the pin at that end of the tie rod which is opposite the clamping device. This says nothing about the location (vertically) of the clamping lever. The axis of the lever is located in the centre of the pin but that is the case, he says, whether the lever is at the same level as the eccentric or below it. He submits that the fact that the eccentric is described as 'connected' to the clamping lever is consistent with the lever being depicted as in figure 1a, that is, connected to each eccentric 'via the torsion rod'. Accordingly, he submits, the specification, including the drawings, depict one 'exemplary embodiment' in which there is a lever located on the torsion bar which is connected to and actuates both fixing means. I find that analysis also places an unwarranted gloss on the words of the claim and is inconsistent with the description in the specification.
124 In this regard, it is worth noting claims 4 and 7:
'4. A telescopic stand according to claim 1, 2 or 3, wherein said clamping lever is located adjacent to the first fixing means.
…
7. The telescopic stand of anyone of claims 1 to 5 wherein each fixing means includes:
an eccentric number [member] actuates [actuated] by the coupling/actuating member; and
a clamp member associated with each eccentric member and moved thereby to secure the intermediate unit to the upper unit in respect of said first fixing means, and to secure the lower unit to its intermediate unit in respect of said second fixing means.'
125 Those claims specifically provide for the clamping lever's location at the level of the first fixing means and the clamping by means of an eccentric.
126 Mr Nicholas' response to the Miller submissions is to point out that, were it not for the association between the clamping lever and the torsion rod, there would be no means to permit or inhibit telescopic movement between the units. This, of course, considers the clamping lever of the Miller tripod only as a single unit. If the two clamping levers of the Miller tripod are used separately, there is telescopic movement. The upper clamp, which does not operate on the torsion rod, affects the movement between the upper and intermediate units. The lower clamp, which does operate on the torsion rod, affects movement between the intermediate and lower units.
127 It is worth repeating what is stated in Kimberly-Clark at [15], citing Welch Perrin at 610 and Interlego at 479, 'the plain and unambiguous meaning of a claim cannot be varied or qualified by reference to the body of the specification. However, terms in the claim which are unclear may be defined or clarified by reference to the body of the specification'.
128 In my view, the words of the claim and in particular integer 18 are clear. However, to the extent that the words of the claim are not clear, in particular to the extent to which they require the torsion rod be the means of permitting or inhibiting telescopic movement, regard may be had to specification.
129 The specification explains the invention as one where the fixing devices of the crossbars are connected by the coupling/actuating member and that it is the coupling/actuating member, the torsion rod, that is connected to the actuating lever, preferably at the upper fixing location. The invention, the 'amazingly simple solution', is said to be based upon the fact that the distance between the two crossbars remains equal and that the coupling/actuating member is attached in order to 'operate' two fixing locations simultaneously 'via this coupling/actuating bar' by means of one actuating lever.
130 That is, the lever operates on the coupling/actuating member which operates or actuates the two fixing locations simultaneously.
131 In the preferred embodiment where the coupling/actuating member is a torsion rod, the torsion rod is connected to two eccentrics which each actuate a clamping member at each crossbar. The upper eccentric is connected to the clamping lever. The pivoting axis of the clamping lever is located in the centre of the pin to which the eccentric is connected. The two eccentrics, one on each crossbar, are connected by the torsion rod so that the two instances of clamping are performed simultaneously when the clamping lever is actuated. In this embodiment, it will be seen that the clamping lever operates on the eccentric of the upper fixing means and that the torsion rod operates as a connection between the functions.
132 As I read the specification, claim 1 requires the clamping lever to be operatively associated with the coupling/actuating member and operates on that member. That is consistent with figure 1a which depicts the clamping lever located below the first fixing means and across coupling/actuating member.
133 Figure 1b, as expanded in figures 4a and 4b, depicts the clamping lever operating on the tie rod and the eccentric, at the location of the first fixing means. The expanded description in the specification of figures 4a and 4b is the 'structure of the crossbars … formed as clamping pieces'.
134 I have come to the conclusion that the specification describes two mechanisms. I appreciate that there is language in the specification that suggests that only one embodiment is described and that the description of the figures is said to be of a single embodiment in different views. On the other hand, it is apparent to me that the figures and the description depict different embodiments as can be seen, for example, in the different positioning and operation of the clamping lever.
135 In one embodiment, the clamping lever operates on the coupling/actuating member which, in turn, permits and inhibits the telescopic movement between all three units. This is achieved by the coupling/actuating member extending between the first and second fixing means, both coupling and actuating them. This is what is claimed in claim 1 and depicted in figure 1a.
136 It is of interest, although not relevant to the construction of claim 1, that the Sachtler tripod which was in evidence is operated by a clamping lever operating on a torsion rod which thereby releases the first fixing means from the upper telescopic unit and permits relative movement between the upper and intermediate units and between the intermediate and lower units.
137 In the other mechanism disclosed in the specification, the clamping lever operates on the tie rod and the eccentric which form part of the first fixing means. The torsion rod is then simply the connector between the first and second fixing means and the operator of the second fixing means. This is what is described in the specification as 'an exemplary embodiment' and depicted in figure 1b and figures 4a and 4b but is not claimed in claim 1. These features are, however, present in claim 7.
138 If the specification describes a single embodiment, as proposed by Mr Catterns, it is the embodiment as claimed in claim 1 and one in which it is the coupling/actuating member that actuates the first and second fixing means. If the specification describes two embodiments, that does not affect the invention as claimed in claim 1, which accords with the description in the specification and figure 1a, if not the further embodiment specifically described in figures 4a and 4b and made the subject of later claims.
139 I should make it clear that my construction comes from the words of claim 1 itself, not from the body of the specification. I note, however, that the construction is consistent with the description of the invention in the specification.
140 Sachtler contends that Miller has taken the substance of the invention, in that it has taken each essential feature of the invention and merely added an additional feature, the two clamping levers. If that were the case, Miller could not escape infringement (3M at 286).
141 Miller contends that the Miller tripod operates in an entirely different manner and does not take all of the essential features of the claims in suit or any combination thereof (Meyers Taylor Pty Ltd v Vicarr Industries Pty Ltd (1977) 137 CLR 228 at 234, in the context of reverse infringement). Mr Catterns submits that the Miller tripod is of a different design which has the advantages of the Sachtler invention with the additional benefit of optional independent operation of the fixing means, rather than operation only 'in unison'.
142 In the patent, the crossbar has attached to it the cam, the pin and the other parts that together form the fixing means. The crossbar slides on the upper unit, clamps to the upper units when the lever is locked and forms the initial piece of the intermediate unit. In the Miller tripod, the top half of the unit on which the two levers are positioned, the part on which the upper lever is positioned, holds the clamping or fixing means. The torsion rod does not extend into this upper half. It is this top half that, functionally speaking, operates as the cross member which slides on the upper unit. Functionally speaking, the lower part is the part fixed to the intermediate unit adjacent to the top of that unit.
143 In my view, the coupling/actuating member of the Miller tripod does couple the first and second fixing means but does not play a role in the operation of the first fixing means; it does not actuate the first fixing means. The torsion rod does permit the first and second fixing means to operate in unison to permit or inhibit telescopic movement of the units and does actuate the second fixing means. The clamping lever is not operably associated with the torsion rod and does not cause operation of the torsion rod. Those three integers are essential integers of Sachtler's claim and are absent from the Miller tripod.
144 While I am of the view that the Improver questions are not the primary tool for assessing infringement nor a replacement for a proper construction of the claims to identify the essential integers and of the allegedly infringing article to ascertain whether those integers are present, I have come to the conclusion that the variants of the Miller tripod do have a material effect upon the way the invention, as claimed in claim 1, works. Accordingly, an application of the Improver questions results in a finding that the Miller tripod is outside claim 1.