The Chemtura Case – Assent from US’ BPAI, but Dissent from India’s IPAB

This post was first published on 29th October, 2014.

Intellectual Property Appellate Board, ORA/14/2009/PT/MUM ANDORA/14/2009/PT/MUM

Decision Date: 24 AUGUST 2012

This post focuses only on the inventive step analysis of IPAB. The question of inventive step arose in a revocation petition before IPAB in which lack of inventive step was one among several grounds. SiNApSE readers will recall this case for its ratio on Section 8 of the Patents Act.

Patent: The patent in question relates to a side bearing pad assembly for absorbing and cushioning compression forces and that dampen lateral rolling motions that occur during the movement of railroad cars.

Claim 1 reads as follows:

“A bearing pad assembly comprising:

a first housing having an exterior surface and defining a bore extending at least part-way through said first housing;

a first load bearing member coupled to said first housing, and defining an outwardly facing first abutment surface;

a second housing defining a bore of a shape similar to said exterior surface of said first housing and adapted to slideably receive said first housing therein;

a second load bearing member coupled to said second housing and defining an outwardly facing second abutment surface opposite to said first abutment surface; and

biasing means including at least one compression spring positioned within the bore of at least the first housing for urging said first and second load bearing members away from one another in response to a load being imposed upon at least one of said first and second abutment surfaces.

Claim 14 reads as follows:

“A bearing pad assembly comprising:

a first housing having a bore extending through said first housing; a first load bearing member coupled to said first housing and defining an abutment surface opposite to said first housing;

a second housing having a bore extending through said second housing, adapted to telescopically receive said first housing;

a second load bearing member coupled to said second housing and defining an abutment surface opposite to said second housing; and

at least one spring in the shape of a toroidal ring positioned within said first housing bore, for urging said first and second abutment surfaces away from each other in response to a load imposed on at least one of said abutment surfaces.”

The application for revocation of the patent cited several prior art references, most of which were put forth by a USPTO examiner, the prosecution history of which was not provided by the patent holder to the patent office. It must be noted that the patent was granted despite the non-submission of the said information. The patent office obviously did not think it as important as the IPAB perceived it. After reviewing the prior art references, the IPAB revoked the patent and did not permit the patent holder to amend the patent to avoid invalidation. The specific paragraphs of the decision are provided hereunder:

“56. This clearly indicates that the claim 1 as worded is not specific to shapes attributed to the compression ring. Broad inventive feature covered by claimed invention relates to side bearing unit for railroad cars assembly which is squarely disclosed in US 4998,997 and the shape of the compression spring as claimed in claim 6 is merely obvious variations as can done by the person skilled in the art based on the teaching in US 136079 which provided solid toroid shaped India rubber spring having high degree of elasticity, together with great bearing strength and which is economical and cheap and it may be applied with advantage to railway cars. Dependent Claim 5 relating to one of preferred material used for the compression spring is merely a matter of normal design procedure for the person skilled in the art. The toroidal rings specified in dependent Claim 6 and independent claim 14 are obvious as suggested by the US 136079. All other features of the dependent claims 2 to 13 such as plate position separating two springs, slip lining etc are merely constructional measures that are within the reach of the customary practice of a person skilled in the art as also taught by US 4,465,799 [slip lining], US 4566,678 (Plate) and non linear compression (known property of rubber). In view of above we are inclined to agree that the invention so far as claimed in the claims are worded is obvious and does not involve any inventive step. The applicant also succeeds in establishing this ground of revocation.”

“57. In relation to the request of respondent No.2 for seeking discretion of the Hon’ble Board at the conclusion of the hearing to amend its claim to restrict the compression spring to a toroid to avoid revocation we must see that the discretion to allow the amendment is not detrimental to the applicants in view of delay and the conduct of the respondent. We find an interesting observation made by Justice Graham in Matbro Ltd vs Machingan (GB) Ltd [1973] RPC 823 at 833 -834 in relation to belated amendments where he stated that “a clear distinction between instances where a patentee knows of prior art which he genuinely, and quite properly in the circumstances, thinks is irrelevant, and other instances where, though he learns of or has been warned of objections which are available against his patent as a result of prior art, yet he takes no steps to put his specification right by way of amendment, or still worse, knowingly persists in retaining it in the unamended and suspect form. In the latter cases delay is culpable because potential defendants and the general public are entitled to plan their activities on the assumption that the patentee, though warned, has decided not to amend. If the patentee, by his conduct, lulls the public into a false sense of security he cannot thereafter be allowed to change his mind and ask for amendment, or at any rate without adequate protection being granted to the public.”

“58. In the instant case the facts are such that the case falls into second category where the patentee was aware of the prior art objections in USPTO and made series of amendments in the specification and claims in that jurisdiction. He failed in the mandatory duty to disclose the prosecution history of USPTO to the respondent 3. .Thus knowingly he took no steps to put his specification right by way of amendment. The conduct of the respondent 3 is susceptible when he knowingly retained the broad claims in the unamended and suspect form in the granted patent. Applying Justice Graham in Matbro observation we are constrained and dissuaded to accept the request of the respondent to amend the claims in lieu of revoking the patent.”

It may be noted here that the US BPAI had allowed the patent grant. However, the IPAB felt that it was too late the amend the application. During a discussion of the technical features of the invention, and related drafting strategy, my colleague Som, a leading mechanical patent prosecutor, commented as follows:

“…One problem I see, apart from the claim, is the specification drafting style and language. The person who has drafted the application has not given enough importance to the toroid shape. Usually when we draft, the inventor-specified construction will be given importance (i.e., the inventor-specified construction is treated as one embodiment) and then the alternatives are mentioned in a different language (different embodiments). For example, in this case, the IPAB-relied portion of the specification states, while toroid shaped rings have been shown and described, the present invention is not limited in this regard as other shapes, such as square, can be employed without departing from the broader aspect of the present invention. Based on the Applicants’ Admitted Prior Art, it is pretty evident that using just a spring/ring was already existing and that toroid shape ring was the most important aspect of the invention. However, the language which the patent drafter has used above makes Toroid rings dispensable/unimportant to the invention and in addition, using the term “present invention” makes a person reading the patent document believe that there is only one embodiment to the present invention.”

In my opinion, this could have been simply written as “In another embodiment, each of the rings 62 define a shape, for example, a square (not shown), without otherwise deterring the intended function of the ring 62 as can be deduced from this specification”

Any thoughts from mechanical patent experts?

Image: from here