本篇討論多年前的經典案例，感謝同事提供參考資料，Caterpillar Tractor Corp. v. Berco, S.P.A., 714 F.2d 1110 (Fed. Cir. 1983)，本篇標題就差不多是本案議題宗旨。
案件資訊：
原告/專利權人：Caterpillar Tractor Co. (Caterpillar)
被告：Berco, S.p.A. (Berco)
系爭專利：US3,841,718
案件背景：
Caterpillar對Berco等人提出侵權告訴，系爭專利'718涉及一種增強型密封環。被告承認其產品type 1侵權，但已經提出修改版的type 2，但是地方法院仍判定type 1與type 2都侵權成立，並發出禁制令。被告對type 2侵權成立判決提起上訴。
系爭專利claim 1如下，描述一種密封組件，內容有點複雜，在此不翻譯了。
1. A seal assembly comprising first and second axially spaced members mounted for relative rotation about a common axis, the first member having a counterbore formed in one face, the second member having an end face opposite the counterbore, a seal ring of tough abrasion resistant material having a crescent shape in cross-section disposed in the counterbore with the crescent shaped cross section defining an annular groove facing the sidewall of the counterbore, the seal ring including a driving flange engaged in non-rotative driving contact with the sidewall and an end wall of the counterbore at the juncture of these walls, a sealing flange engaged in annular face sealing rotative contact with the end face of the second member, the driving said sealing flanges being interconnected by a wall section of substantially thinner cross section than that of the flanges, the thin dimension imparting thereto a substantial lateral flexibility while retaining a torsional modulus characteristic of the tough abrasion resistant material, and a load ring of elastomeric material having substantial spring response characteristics, said load ring being disposed within the annular groove of the crescent shaped seal ring and engaging substantially the entire inner wall surface of the sealing flange and being axially compressed between the driving flange and the sealing flange, the interconnecting thin wall section having a resiliency and torsional modulus such that virtually all driving torque is transmitted from said driving flange to said seal flange therethrough, whereas virtually all of the seal flange face load is derived from compression of said load ring.
Claim 10描述一種在圓形空腔內的密封件：
10. A seal assembly in an annular cavity formed by first and second members which are subject to relative rotation, the first member forming the axially facing end wall and a radially facing sidewall of the cavity, the second member having an end face forming another axially facing end wall of the cavity opposite the one axially facing end wall, comprising a seal ring of tough abrasion-resistant material having a crescent shape in cross-section, the seal ring being disposed in the annular cavity with an annular groove of the crescent-shaped seal ring facing the sidewall of the cavity, the seal ring having a driving flange engaged in non-rotative driving contact with the sidewall and the one end wall of the cavity at the junction of these walls and a sealing flange engaged in face sealing rotative contact with the end face of the second member, the seal ring also having a thin-wall section connecting the flanges and providing a flexible hinge therebetween, and a load ring of resilient elastomeric material being disposed adjacent the sidewall of the first member and encompassed by the crescent-shaped cross-section of the seal ring and engaging substantially the entire inner wall surface of the sealing flange whereby the load ring is axially compressed between the driving flange and the sealing flange, axially acting forces for urging the sealing flange against the end wall of the second member and maintaining substantially constant sealing engagement therebetween are provided substantially by compression of the load ring.
在系爭專利專利審查過程中，先在1971年提出最早申請案 - 申請號116,157，審查委員對此申請案發出核駁理由，主要新穎性引證案為US3,390,922（這件後來也轉讓給Caterpillar），審查委員也提出112不明確的核駁意見，認為claim中用語"thin"不明確，因為沒有比較基礎、也沒有定義。
後來Caterpillar在1972年提出CIP申請案（申請號300,817），就補充"thin"的定義，後來1974年核准專利，即本次系爭專利 - US3,841,718。
案件進入CAFC：
經比對系爭專利範圍與被告Berco的產品，爭議在請求項中的幾段話，如claim 1中的「a wall section of substantially thinner cross section than that of the flanges . . . .」、claim 19的「the wall section being of thin cross-section relative to that of the ends. . . . .」，這兩段話是要界定"樞紐壁/hinge wall"有比其兩側凸緣（flange）更薄的截面。
被告侵權產品Berco的type 2產品的密封件的樞紐比密封凸緣（sealing flange）還薄，但是並沒有比驅動凸緣（driving flange）更薄。
因此在文義讀取的判斷上，Berco的type 2產品並沒有侵害系爭專利權（no literal infringement）。
於是原告Caterpillar就主張適用"均等論（doctrine of equivalents）"，主張Berco的type 2產品以實質相同方法執行實際相同的功能以達成相同的結果（"perform substantially the same function in substantially the same way to obtain the same result"）。
經法院審理，認為Berco的type 2產品的密封件與系爭專利範圍有實質相同的結構，並以實質相同的方法產生實質相同的結果，因此侵權判定適用均等論。（編按，但是，其中卻沒有任何記錄顯示較薄的驅動凸緣（driving flange）影響產品的運作或是得出的結果，也就是說，文義沒有讀取的特徵並沒有涉及均等論的判斷。）
針對以上均等論適用的決定，被告Berco主張「歷史禁反言/doctrine of file history estoppel」反擊。
針對claims 1, 19：
特別地，經查系爭專利'718中的claims 1, 19中包括了CIP案新增的特徵，法院認為過去的各種答辯歷史並不能全部套用，但明顯地，Caterpillar並沒有定義所述樞紐（hinge）的截面比其凸緣的一個還薄，並且也沒有相關的刪除與修正，也就是說，Caterpillar並沒有通過修正或是答辯影響關於其樞紐截面比所述兩種凸緣更薄的解釋，並沒有對此產生禁反言，因此專利範圍的解釋適用均等論，侵權成立。（法院澄清，針對112的修正並非是為了要區隔先前技術，因此並沒有產生歷史禁反言）
針對claim 10：
系爭專利claim 10中有句話："a thinwall section connecting the flanges and providing a flexible hinge therebetween . . . ."，法院判決claim 10直接讀入Berco的type 2產品，侵權成立。
針對以上claim 10侵權成立的判決，Berco等人主張"thin"沒有更薄的意思，不同於"thinner than the flanges"的解釋，但是法院否決，認為系爭專利'718說明書記載了何謂"thin"，並描述相關實施例，因此法院不覺得"thin"不是沒有意義，因此仍判定侵權成立。
（以上判決與論述都是侵權案例的經典，但仍有以下重點）
【本篇重點】
針對以上"打擊"，敗訴的Berco等人就尋求原告Caterpillar的外國案、外國委任律師等針對其他對應外國專利的意見，如德國、英國，也就是希望利用本系爭專利在他國進行審查答辯時為了要區隔先前技術的主張來影響目前訴訟中的專利範圍解釋，然而，法院並不採用。
其中一段話：
"Though no authority is cited for the proposition that instructions to foreign counsel and a representation to foreign patent offices should be considered, and the varying legal and procedural requirements for obtaining patent protection in foreign countries might render consideration of certain types of representations inappropriate, there is ample such authority in decisions of other courts and when such matters comprise relevant evidence they must be considered."
儘管沒有任何權威指出應考慮給當事人的外國（美國以外）律師或外國專利局的代表的指示（instruction），基於不同法律與程序要求取得的外國專利成為某種形式的考慮基礎並不恰當。不過，法院也沒有全然否決，然而，在其他法院決定的權威下，若證據有相關性，仍應被考慮。（翻譯得不好，請見諒）
本案侵權成立（claims 1, 19均等論適用、claim 10文義侵害成立）。
my two cents:
以上侵權案例經典地涉及審查歷史、文義讀取、均等論，以及禁反言等議題。
本案例算是蠻久以前的案子，但是其中CIP產生的影響卻是頗為深刻，因為系爭專利為CIP案，很多針對其母案的審查歷史或是答辯的主張/限縮都可能不適用後續的CIP案（獨立請求項都有cip新增特徵），這倒是看到了CIP案的好處（雖然後來主流都不建議CIP申請案）。
Ron
