B e f o r e :
| (1) WEATHERFORD UK LIMITED
(2) WEATHERFORD/LAMB INC
|(1) BJ TUBULAR SERVICES LTD
(2) BJ SERVICES COMPANY (UK) LTD
Daniel Alexander QC and Richard Meade, instructed by Bristows, appeared for the Defendants.
Dates of hearing: 13-16 December 2005
Crown Copyright ©
(a). The Ferrari 535 series crane (brochure, specification sheet and the crane itself called collectively 'the Ferrari Crane'),
(b) The General Catalogue of Maritime Hydraulics for 1990-91, p 17 ('MH arm'),
(c) US patent No 4,843,945 ('Dinsdale') and a late entrant,
(d) BJ's own Leadhand Mk I tong positioning device.
BJ also allege that the Patent is invalid on the ground of obviousness in the light of the common general knowledge.
Introductory Technical Background
"The combination of an existing tugger line to support the power tong and a light weight hydraulic arm to position the tong horizontally appears to be a natural evolution. Both devices were available before 1997 and each has been in use for many years in the very same application of handling power tongs."
In spite of this, I understand that the day of the human roughneck has not drawn to a close even now. As we shall see, the Patent opens with such a mechanical proposal for tong positioning. In my judgment, the mechanical positioning of tongs was certainly known and used before the priority date but there is some dispute as to whether it actually formed part of the common general knowledge.
(i) that this is the only occasion in the Patent in which use of the tugger line is invoked, and
(ii) that the Patent gives no indication of the amount that the piston and cylinder assembly (101) has to be withdrawn in the inoperative position nor the degree that the assembly has to be pivoted to an 'upwardly extending axis'.
The 'upwardly extending axis' as shown in Fig 4 was about 55° whereas in Fig 5 it was only about 26° to the horizontal.
(i) An apparatus for positioning a tong
(ii) comprising a piston and cylinder assembly (101) and
(iii)a mounting assembly (102) therefore characterised in that:
(iv) the said piston and cylinder assembly can be pivoted between an operative position in which it can be extended and retracted to move a tong towards and away from a string of tubulars, and
(v) an inoperative position in which the said piston and cylinder assembly extends along an upwardly extending axis, and
(vi) with part of said piston and cylinder assembly disposed either side of said mounting assembly.
(i) an apparatus as claimed in any of the previous claims wherein the said mounting assembly (102)
(ii) comprises a bearer (107) which can be clamped to a structural member in a drilling tower
(iii) a carriage (111) pivotally mounted on said bearer, and
(iv) a clamp assembly (112) for securing said piston and cylinder assembly (101) to said mounting assembly (102).
The Inventive Concept
(a) First, the free end of the extendible arm is hydraulically retracted from its work point into the arm in a well-known manner.
(b) Next, the arm with the free end thus retracted, is caused to be tilted 'upwards' about a pivot thus moving it more out of the way.
(c) Finally (and additionally), the arm is located yet further away from the drilling area by arranging for it to lie in repose 'to either side of the mounting assembly'.
The Skilled Addressee
The Expert Witnesses
The Common General Knowledge
" Storing something in a vertical or near vertical position, reducing a telescopic structure to its shortest possible length and sliding the structure back through a sleeve [were] well known ideas which form part of the skilled addressee's common general knowledge."
Again, I am not surprised that this statement went unchallenged in cross-examination.
Claim 1 integers
Claim 4 integers
'The present invention provides a simple and elegant solution to the problem. In particular the clamp assembly (112) can simply be slackened, the piston and cylinder (101) can be slid on the carriage (111) until the extremity (114) lies adjacent to the mounting assembly (102) and the clamp assembly (112) re-tightened'.[Emphasis added]
Mr Birss submitted that in context the 'clamp assembly' was a temporary clamp. I agree. The next issue is whether claim 4 requires the retracted telescopic arm to be slidable between the two positions relative to the mounting assembly so as to achieve the benefit of the third stowage position of claim 1. 'Carriage' in context is any supporting structure which (on unclamping what is supported) may allow the assembly to move longitudinally relative to it - to a desired extent - before being re-clamped to maintain the arm in its inoperative position ready if desired, for use again.
Claim 1/Configurations 1 and 2
Claim 1/Configurations 3 and 4
"Utilising the end mounting plates D always leaves a very short length of the overall telescopic arm, half the length of the saddle, to one side of the pivot point at whatever angle the arm lies, operative or inoperative."
Weatherford's argument was based of course on the relevant 'point' being the pivot point; this is an argument which I have rejected. In summary, if claim 1 is valid, only Configuration 1 infringes it.
Claim 4: 'Carriage' and 'clamp assembly'
The Prior Art Citations