Douglas Dynamics, LLC v. Buyers Products Company

Filing 91

ORDER construing claims and amending scheduling order; denying 71 defendant's motion to exclude expert opinions. Dispositive motions due 5/3/2010. Signed by Chief Judge Barbara B. Crabb on 3/2/2010. (llj)

IN THE UNITED STATES DISTRICT COURT FO R THE WESTERN DISTRICT OF WISCONSIN --------------------------------------------D O U G L AS DYNAMICS, LLC, O PIN IO N AND ORDER Plaintiff, 0 9 - cv -2 6 1 - b b c v. B U Y ER S PRODUCTS COMPANY, D efendan t. --------------------------------------------T h is is a patent infringement lawsuit in which plaintiff Douglas Dynamics, LLC alleges that defendant Buyers Products Company is infringing five of plaintiff's patents relating to snow plows. On November 17, 2009, I granted the parties' motions to construe 1 6 claim terms and denied their request for a court hearing. Dkt. #81. Now before the cou rt is the question of the construction of the 16 claim terms. All five patents-in-suit relate to snow plow attachments for vehicles. United States Patent No. 4,999,935 (the `935 patent) covers a "Hydraulic System and Apparatus for use w ith Vehicle Accessory Units." More specifically, the patent "relates to a hydraulic system for a vehicle mounted, power operated plow blade." `935 pat., Abstract. United States Patent No. 5,420,480 (the `480 patent) covers an "Automatic Headlamp Switching System."

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U n ited States Patent No. Re. 35,700 (the `700 patent) covers a "Removable Snowplow Assem bly with Pivotable Lift Stand." United States Patent No. 5,353,530 (the `530 patent) covers a "Quick Mounting Snow Plow Assembly." United States Patent No. 6,944,978 (the `97 8 patent) covers a "Snowplow and Mount Assembly." B efo re construing the terms, I must address defendant's request to exclude from consideration the opinions of plaintiff's expert, Dr. Charles Garris. Defendant contends that it was sandbagged by Garris's opinion on claim terms. Regardless whether plaintiff's actions am ou nt to sandbagging, none of its actions require the exclusion of Garris's opinions. First, the Preliminary Pretrial Conference Order, dkt. #11, does not require disclosure of experts un til February 26, 2010. Plaintiff need not disclose an expert witness until the time ordered b y the court. Fed. R. Civ. P. 26(a)(2)(C). Plaintiff's disclosure of Garris at the end of O ctober 2009 was well before the court ordered disclosure date. Defendant also contends that plaintiff changed its claims construction right before the deadline for proposed constructions, but those changes were necessitated by defendant's no nin fringem ent arguments. Further, it is not improper to alter a proposed construction in respo nse to an opposing party's contentions. Although plaintiff had to produce a claims c h art by August 21, 2009, it was not required to disclose its proposed construction of disputed terms until October 26, 2009. It did just that. Accordingly, defendant's request that Garris's testimony and opinions be excluded will be denied.

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F ro m the parties' briefs, the patent claims, patent specification and prosecution history, I conclude that judicial construction of six terms is warranted.

O PIN IO N A. Claims Construction Standards W hen construing claims, the starting point is the so-called intrinsic evidence: the claim s themselves, the patent specification and the prosecution history. Teleflex, Inc. v. Ficosa North America Corp., 299 F.3d 1313, 1325 (Fed. Cir. 2002). Examination of the claim s' language is the starting point for the well established process of claim construction. "Claim construction must adhere carefully to the precise language of the claims that the p aten t [examiner] has allowed." Ardisam, Inc. v. Ameristep, Inc., 336 F. Supp. 2d 867, 879 (W .D . Wis. 2004) (citing Autogiro Co. of America v. United States, 384 F.2d 391, 396 (Ct. Cl. 1967)). The language is to be construed as it would be understood by one of ordinary skill in the relevant art, given its context and the other patent claims. Rexnord Corp. v. L aitram Corp., 274 F.3d 1336, 1342 (Fed. Cir. 2001). Moreover, district courts must rem ain aware that "[t]he patent applicant may not have used words consistent with the dictionary definition because an applicant can act as his or her own lexicographer or may disavo w or disclaim aspects of a definition `by using words or expression of manifest exclusion or restriction, representing a clear disavowal of claim scope.'" Ardisam, 336 F.

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S u pp . 2d at 879-80 (quoting Golight, Inc. v. Wal-Mart Stores, Inc., 355 F.3d 1327, 1331 (Fed. Cir. 2004)). This initial construction is then considered in light of the specification to determine w hether the inventor expressed a different meaning for the language, whether the preferred em bo dim ent is consistent with the initial interpretation and whether the inventor specifically d isclaim ed certain subject matter. Rexnord, 274 F.3d at 1342-43. The specification

co n tain s a written description of the invention that is meant to help explain the invention an d possibly define claim terms, Markman v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed. Cir. 1995), but as a general rule, "limitations from the specification are not to be read in to the claims." Golight, 355 F.3d at 1331. Finally, the interpretation is examined for co n sisten cy with the patent's prosecution history and any disclaimers made therein. R e xn o rd , 274 F.3d at 1343. Last, a court may consult extrinsic evidence, such as dictionaries, treatises and expert testim ony for background information and to "shed useful light on relevant art." Phillips

v. AWH Corp., 415 F.3d 1303, 1317 (Fed. Cir. 2005) (internal citations omitted). In general, this type of evidence is less reliable than intrinsic evidence in determining the m eanin g of claim terms and is "unlikely to result in a reliable interpretation of patent claim sco p e unless considered in the context of the intrinsic evidence." Id. at 1318-19.

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B . Means-Plus-Function Limitations C o n struin g claims containing means-plus-function limitations requires a slightly d ifferen t process because such claims fall under an exception to the general rule about not read in g limitations from the specification into the claims. According to 35 U.S.C. § 112 ¶6, An element in a claim for a combination may be expressed as a means or step fo r performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the co r resp o nd in g structure, material, or acts described in the specification and equ ivalents thereof. In other words, if a claim includes a function but fails to identify the structure that performs th e function, the structure is limited to the examples provided in the specification. C on struction of a means-plus-function limitation involves a two-step analysis. First, th e claimed function must be identified. Omega Engineering, Inc. v. Raytek Corp., 334 F.3d 1314 , 1321 (Fed. Cir. 2003). "Ordinary principles of claim construction govern

interpretation of the claim language used to describe the function." Cardiac Pacemakers, I n c . v. St. Jude Medical, Inc., 296 F.3d 1106, 1113 (Fed. Cir. 2002). For example, "it is im p ro p er to restrict a means-plus-function limitation by adopting a function different from th at explicitly recited in the claim." Creo Products, Inc. v. Presstek, Inc., 305 F.3d 1337, 13 46 (Fed. Cir. 2002). In other words, "[t]he court must construe the function . . . to include the limitations contained in the claim language, and only those limitations." Cardiac P a c e m a k e r s , 296 F.3d at 1113. Second, the court must "ascertain the corresponding

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stru ctu res in the written description that perform those functions." Omega Engineering, 334 F .3 d at 1321. "[T]o qualify as corresponding, the structure must not only perform the claim ed function, but the specification must clearly associate the structure with performance of the function." Cardiac Pacemakers, 296 F.3d at 1113. "In other words, the structure m u st be necessary to perform the claimed function." Omega Engineering, 334 F.3d at 1321. In determining whether an element falls under § 112, ¶6, "[u]se of the word `means' in claim language creates a presumption that § 112, ¶6 applies." TriMed, Inc. v. Stryker

C orp ., 514 F.3d 1256, 1259 (Fed. Cir. 2008). However, the presumption is not conclusive. Sage Products, Inc. v. Devon Industries, Inc., 126 F.3d 1420, 1427 (Fed. Cir. 1997). If "the claim recites sufficient structure for performing the described functions in their entirety, the presum ptio n of § 112 ¶6 is overcome­the limitation is not a means-plus-function

lim itation ." TriMed, 514 F.3d at 1259. Further, the presumption is overcome even when th e element contains the word "means" if the claim fails to specify a corresponding function fo r the "means." Sage Products, Inc., 126 F.3d at 1427.

C . The `935 Patent 1 . Means for mounting said plow blade for vertical movement and horizontal movement The parties agree that the term "means for mounting said plow blade for vertical m ov em ent and horizontal movement" as used in claim 1 of the `935 patent is a means-plus-

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function limitation to which § 112 ¶6 applies. The parties further agree that the claimed function is the mounting of the plow blade for vertical and horizontal movement. They d isagree about what structures in the specification correspond to the claimed function. B ecause the corresponding structures depend on the claimed function, it is helpful to look more closely at the precise function. Thus, although I agree with the parties' general description of the function, further explanation is necessary. It is clear from the claim la n guage that "mounting the plow blade" merely means attaching the plow blade to the vehicle. The claim language contains an additional limitation on how the plow blade must be attached, which is that the attachment must permit vertical and horizontal movement. T hus, I find that the claimed function is attaching the plow blade to the vehicle in a m a n n er that permits vertical and horizontal movement. T o find the corresponding structure or structures, one must look for structures "clearly linked or associated" with the claimed function. Medtronic, Inc. v. Advanced C a rd io vascu lar Systems, Inc., 248 F.3d 1303, 1311 (Fed. Cir. 2001). Figure 1 in the `935 patent illustrates a snow plow blade mounted or attached to a vehicle:

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T he description of Figure 1 provides an explanation about how the plow blade is attached and how it moves vertically and horizontally: Fram e 14 is pivotally connected by pins 16 (only one visible in the drawing) to an extension 17 attached to the vehicle frame (not shown) and supports a sno w plow blade 18 for movement about vertical and horizontal axes in a m an n er to be described more completely hereinafter. Vertical movement of plow blade 18 about a horizontal axes [sic] defined by pins 16 is achieved by m o v e m e n t of ram 20 of hydraulic cylinder provided as part of power unit. R am 20 is connected to frame 14 through a lever arm 22 which is in turn pivo tally connected to frame 11 by pivot pin 24. Lever arm 22 is connected to frame 14 by chain 26. .... The system is capable of producing horizontal movement of snowplow blade

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1 8. In this connection, frame 14 includes an A-frame portion 140 which is pivo tally connected by pins 16 to extension 17 and an arcuate frame portion 1 4 2 connected to plow blade 18. Frame portion 142 is connected to and p ivo ts relative to the A-frame about a vertical pivot axis defined by pin 146. . . . Hydraulic cylinders 154 and 155 are connected between frame portion 1 4 2 and the A-frame and operation of these hydraulic cylinders is effective to p ivo t the plow blade horizontally about pin 146 to a desired plowing angle. `9 35 pat., col. 2, lns. 54-65 and col. 3, lns. 12-31. According to the description, the "clearly link ed or associated" structures [with attaching the plow blade to the vehicle in a manner that permits vertical and horizontal movement] are (1) a frame 14 that includes an A-frame 1 4 0 and an additional frame portion 142 attached to the plow blade using a pin 146 and attached to the vehicle using pins 16 and 24; (2) an extension 17; a chain 26; and a lever arm 22. (I include the numbers from Figure 1 solely to provide a visual example of the s tr u c t u r e s . It is not necessary that the corresponding structures look like their visual

c o u n t e r p a r t .) Plaintiff contends that the pin 24, chain 26 and lever arm 22 should not be structures in clu ded in construction of the claim because they are part of the function ( moving the plow blade vertically). Plaintiff is correct that the pin, chain and lever arm are used to move the p lo w blade vertically. However, structures may perform more than one function, as the pin, chain and lever arm do. Medtronic, Inc., 248 F.3d at 1313. Besides actually moving the p lo w blade, those structures are necessary to mount the plow blade in a manner that will perm it vertical movement. Without attaching the frame 14 to the lever arm 22 using a

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chain 26 and to the vehicle using a pin 24, the plow blade would not move vertically. D efendant contends that several additional structures should be included in the co n stru ctio n : the additional frame portion 142 must be an arcuate frame and the ram 20 that raises and lowers the lever arm should be included along with the hydraulic cylinders 1 5 4 and 155 that move the plow blade horizontally. With respect to the additional frame po rtion , although the specification refers initially to the frame portion associated with num ber 142 in Figure 1 as the "arcuate frame" portion, additional references to 142 cite on ly the "frame portion" when explaining how the plow blade pivots horizontally. `935 pat., col. 3, lns. 15, 17 and 28. Additional use of the term "arcuate" in the specification is linked to "pivotal movement of the plow blade in the event the blade should strike an obstruction such as a rock or the like." Id., col. 3, lns. 19 and 25. Nothing in the specification or claim language suggests that the additional frame portion must be arcuate to permit horizontal m o vem en t of the plow blade. Simply put, the arcuate shape of the additional frame is not clearly linked to the claimed function. Thus, the additional frame portion need not be arcu ate to accomplish the claimed function. The ram is another structure not clearly linked to the claimed function. The ram produces vertical movement of the plow blade and connects the lift unit to the plow blade so that the plow blade can move vertically. Id., col. 2, lns. 59-62. The same is true for the hydraulic cylinders except that they produce horizontal plow blade movement. However,

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neither the ram nor the hydraulic cylinders are used for mounting the plow blade to the vehicle to permit vertical or horizontal movement, which is the claimed function. Because the additional structures that defendant identifies are not clearly linked or associated with the claimed function, its proposed construction of the claim term fails.

2. A hydraulic power unit I conclude that the term "a hydraulic power unit" as used in claim 1 of the `935 patent means a group of hydraulic components, including a hydraulic fluid reservoir, a pump and lift hydraulic cylinder. The parties dispute whether the claim term should be construed to be a "unitary" hydraulic power system. I agree with plaintiff that adding the w ord "unitary" to describe the hydraulic components adds nothing but confusion to the construction of the term and would be an improper reading of a limitation from the specificatio n into the claim. D efendant contends that referring to the hydraulic components as "a unitary hydrau lic power system formed on a base" merely defines "unit" as the term is used in claim 1 . (It maintains that its plows lack a "unitary hydraulic power unit." Def.'s Br., dkt. #72, at 20.) However, defendant's reference to a "unitary hydraulic power unit" makes it clear that "unitary" is intended to express something in addition to "unit." The additional som ething expressed by the use of the word "unitary" is the concept of locating the hydraulic

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com po nen ts on the same base or confining them to a single structure. Defendant cites the Summary of the Invention in the specification to support its contention. Therein lies the problem. "[L]imitations from the specification are not to be read into the claims." Golight, 355 F.3d at 1331. The specification provides a preferred em bo dim ent, but the scope of the claim term depends on the claim and not a preferred em bo dim ent. Kara Technology Inc. v. Stamps.com Inc., 582 F.3d 1341, 1347 (Fed. Cir. 20 09 ) ("The claims, not specification embodiments, define the scope of patent protection."). N o th in g in the patent suggests that the patentee was acting as his own lexicographer or disavow ing claim scope when he used the term "unit." Patentees are not required to provide an example of every embodiment of a claimed structure in a patent's specification. By itself, th e disclosure of only one embodiment does not justify limiting a claim's scope to that single disclosed embodiment. Abbott Laboratories v. Sandoz, Inc., 566 F.3d 1282, 1290 (Fed. Cir. 20 09 ). Thus, although the hydraulic power unit as claimed in the patent requires certain hydraulic components, the claim does not require locating those components on the same base. In other words, nothing in the patent limits the hydraulic power unit to a unitary system as defendant has proposed. In addition to its unitary argument, defendant contends that a proper construction of a hydraulic power unit should state that it does not include the manifold. Such an addition is unnecessary. Claim 1 recites "said manifold connected to and mounted on said

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hydraulic power unit." `935 pat., col. 6, lns. 62-63. This portion of the claim makes it clear that although the manifold is separate from the hydraulic power unit, it must be connected to and mounted on it. Therefore, it would be superfluous to say that the manifold is not included in the construction of "a hydraulic power unit."

3. Manifold connected to and mounted on said hydraulic power unit I conclude that "manifold connected to and mounted on said hydraulic power unit" as used in claim 1 of the `935 patent does not need construction. Its plain and ordinary m eanin g is easily discernible from the claim language. Nothing in either party's proposed construction is necessary to elaborate the term; nothing in the claim language or the sp ecificatio n necessitates a special definition. Therefore, the plain and ordinary meaning controls. Northern Telecom Ltd. v. Samsung Electrics Co., 215 F.3d 1281, 1295 (Fed. Cir. 20 00 ).

4. Means defining fluid flow passages in said manifold The parties dispute whether "means defining fluid flow passages in said manifold" as u sed in claim 1 of the `935 patent is a means-plus-function limitation. The claim's use of the word "means" raises the presumption that the limitation is means-plus-function, but plaintiff contends that the claim language provides sufficient structure to overcome the

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presum ption , placing the limitation outside the scope of § 112 ¶6. I disagree. In plaintiff's view, the fluid flow passages are a structure and there cannot be a more specific structure to perform the function of defining fluid flow passages that communicate w ith hydraulic cylinders. However, a fluid flow passage is not a self-defining term. It is necessary to have some other structure or structures to create fluid flow passages that com m unicate with the hydraulic cylinder means as claimed in claim 1. Therefore, the term is properly constructed as a means-plus-function limitation. In construing the term, it is helpful to read it in context: a manifold including means defining fluid flow passages in said manifold communicating with said hydraulic cylinder m eans. `935 pat., col. 6, lns. 56-58. According to the claim language the term's function is d e f in in g fluid flow passages that communicate with the hydraulic cylinder means. D e fen dan t includes an additional function in its proposed construction. I understand defendan t to contend that the function should include communicating with the solenoid v a l v e means and being operative to selectively direct fluid to said lift hydraulic cylinder m eans and angle hydraulic cylinder means. Defendant is mistaken in its reading of the claim language. Although the language is somewhat muddled, it is clear that the solenoid valve m eans is a part of the manifold, separate from the means defining fluid flow passages. A plain reading of the claim language establishes that although a solenoid valve means is located within the structures establishing the fluid flow passages, it is the solenoid valve

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m eans that selectively directs fluid and not the fluid flow passages. W ith the claimed function defined, the next step is determining the corresponding structures. Defendant contends that the corresponding structures are all the valving, ports, flo w channels and ancillary mechanisms in the manifold, as identified in Figures 3A, 3B and 4 through 7. Defendant's proposed construction includes too much. The specification states that "Figs. 3A and 3B show the actual structural relationships within the valve manifold, i.e., valves, ports and flow channels." Id., col. 5, lns. 34-36. According to the claim language, the manifold includes both a means defining fluid flow passages and a solenoid valve means. Id ., col. 6, lns. 56-61. Thus, despite defendant's contention to the contrary, not everything pictured in Figures 3A or 3B is associated with the means defining fluid flow passages. N onetheless, many of the structures identified in Figures 3A, 3B and 4 through 7 are the only structures linked to defining fluid flow passages that communicate with hydraulic fluid cylinders. When there is only one embodiment of a structure linked or associated with a claimed function, the claimed function is limited to that embodiment of the structure and its equivalents. E.g., Cross Medical Products, Inc. v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293, 1304 (Fed. Cir. 2005) ( "because there is only one embodiment described in the sp ecificatio n . . . there is no basis on which to extend the limitation to cover alternative, nondisclosed structures not shown to be structurally equivalent"). Figure 3A, provided below, is an illustration of the entire manifold, which includes

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th e structures for executing the claimed function.

Figure 6, provided below, illustrates the flow path to the right angle hydraulic cylinder 76.

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T he structures that define fluid flow passages that communicate with both the lift 72 and angled 74 and 76 hydraulic cylinders are those shown in Figures 3A, 3B and 4 through 7 and listed in column 5, lines 38 through 68 and column 6, lines 1 through 11 and their equivalents. For example, hydraulic conduits 167 and 169, ports 200, 202 and 204, passages 88, 94 and 100 and valves 80, 82 and 84 are clearly associated with performance of the claimed function. E.g., `935 pat., col. 5, lns. 38-60. They all play a necessary role in d efin in g the fluid passages used to communicate with the hydraulic cylinders. E.g., id., col 5, lns. 53-60, 61-64 and 65-col. 6, ln. 1 ("fluid flows from reservoir . . . through passage . . . to pressurize cylinder 72"; "fluid returns through passage"; and "the flow path is again to the four way valve through passage . . . to pressurize cylinder 76"). Plaintiff contends that channels are the only structure necessary for performing the claim ed function and that to require more would be reading limitations from the sp ecifica tio n into the claim. Plaintiff would be correct but for the fact that the general rule against reading limitations from the specification into claims does not apply to means-plusfunction limitations. A patentee's decision to use a means-plus-function limitation carries a price: "use of that convenience is limitation of the claim to the means specified in the w ritten description and equivalents thereof." Texas Digital Systems, Inc. v Telegenix, Inc., 3 0 8 F.3d 1193, 1208 (Fed. Cir. 2002) (quoting O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 15 83 (Fed. Cir. 1997)). Defining fluid flow passages that communicate with hydraulic

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cylinders requires more than channels according to the specification. Without conduits, ports and valves, there would be a connection but no communication. Those structures are necessary for the communication aspect of the claimed function, which means that plaintiff's proposed construction is incorrect. I conclude that "means defining fluid flow passages in said manifold" is a means plus function limitation. Its function is to define fluid flow passages that communicate with the hydraulic cylinder means. The structures clearly linked to performing that function are pro vided in Figures 3A, 3B and 4 through 7, which includes hydraulic conduits, ports, passages and valves.

D . The `480 Patent 1 . Switching means The parties agree that the term "switching means" as used in claims 7 and 18 of the `48 0 patent is a means-plus-function limitation to which § 112 ¶6 applies. The first step in construing "switching means" is to define the claimed function, which is different in the sep arate independent claims. According to claim 7, the claimed function is to interrupt the prim ary circuit and connect the secondary light circuit to the energy source so that the secondary light source is selectively energizable and the primary circuit is de-

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energized. According to claim 18, the claimed function is to interrupt the primary circuit an d connect the energy source to the secondary light source so that the secondary ligh t source is selectively energizable in response to the switch. T he next step is to identify the structures in the specification that are clearly linked to performing the claimed functions. The specification does not refer to a "switching means" but it does identify a "second switch means" that performs the claimed function. `480 pat., col. 1, lns. 62-66; col. 4, lns. 23-26 ("the second switch means 144 interrupts the primary circu i t 46 and simultaneously completes the secondary circuit 76 thus illuminating the sno w plow headlamps"). The specification provides one embodiment of the second switch m eans: The second switch means 144 in the preferred embodiment constitutes a first relay 146 and a second relay 148. The first and second relays 146 and 148 respectively are of the single pole double throw (SPDT) type. Id., col. 4, lns. 33-36. Although the functions vary slightly, the structures corresponding to the functions are the same. Thus, the structures that engage in the claimed functions are first and second relays of a single pole double throw type and their equivalents. D efendant seeks to add information to the corresponding structure about how the structures are energized. Such an addition would be improper. How the structures are en ergized is something left for the claim language. E.g., id., col. 9, ln. 64 ("switching means autom atically activated when . . ."); col. 12, lns. 22-23 ("selectively energizable in response

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to said switch"). These claim requirements regarding the "switching means" need not be in co rp o rated into the structures corresponding to the claimed function. Plaintiff contends that requiring the relays to be single pole double throw is improper because that limitation is found only in the specification. However, as explained before, w hen a patentee chooses to use a means-plus-function limitation in a claim, the claim is lim ited to the means specified in the written description and its equivalents. Texas Digital System s, Inc., 308 F.3d at 1208. Therefore, the limitations on structure set forth in the sp ecificatio n properly limit "switching means" in claims 7 and 18.

2. Switch I conclude that the term "switch" as used in claims 7 and 18 of the `480 patent does not need construction because its plain and ordinary meaning is easily discernible from the claim language. The term is clear and nothing in the claim language or the specification necessitates a special definition. Therefore, the plain and ordinary meaning controls.

N orthern Telecom Ltd. v. Samsung Electrics Co., 215 F.3d 1281, 1295 (Fed. Cir. 2000). I note that in its proposed construction, defendant seeks to impose limitations from the specificationthat do not appear in the claim itself, such as a low and high beam selector. Such a construction would be improper. Golight, 355 F.3d at 1331 ("[L]imitations from the specification are not to be read into the claims.").

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3 . First switch means T he parties dispute whether the term "first switch means" as used in claims 1, 2, 9 and 16 of the `480 patent is a means-plus-function limitation. The claims' use of the word " m e an s" raises the presumption that the limitation is means-plus-function. Plaintiff

co n ten ds that the word "switch" provides sufficient structure to overcome the presumption, p lacin g the limitation outside the scope of § 112 ¶6. Plaintiff is mistaken. A claim using the word "means" provides sufficient structure when "claim language specifies a specific physical structure that performs the function." Altiris, Inc. v. Symantec Co rp., 318 F.3d 1363, 1376 (Fed. Cir. 2003). For example, in Cole v. Kimberly-Clark C orp ., 102 F.3d 524, 531 (Fed. Cir. 1996), the Court of Appeals for the Federal Circuit fo und that the term "perforation means . . . for tearing" was not a means-plus-function lim itatio n because the claim language "describe[d] the structure supporting the tearing function (i.e., perforations)[,] . . . its location (extending from the leg band to the waist band) and extent (extending through the outer impermeable layer)." The appellate court reason ed that "[a]n element with such a detailed recitation of its structure, as opposed to its function, cannot meet the requirements of [§ 112 ¶6]." Id. Also, in Envirco Corp. v. Clestra Cleanroom , Inc., 209 F.3d 1360, 1365 (Fed. Cir. 2000), the Court of Appeals for the Federal C ircu it found that the term "second baffle means" was not a means-plus-function limitation because "the term `baffle' itself impart[ed] structure, meaning a surface which deflects air"

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an d "the claims describe[d] the particular structure of th[at] particular baffle (`having inner su rfaces for directing airflow . . . radially outward . . . and between said first baffle means and said air filter means')." Plaintiff contends that like perforation means or second baffle means, first switch m ean s identifies a sufficient structure to overcome the means-plus-function presumption. H ow ever, the claim language in the `480 patent is readily distinguishable from the claim language in both Cole and Envirco because it does not describe the specific physical structure correspo nd ing to the first switch means. In claim one, the term is described as a first switch means for connecting said energy source and said primary light source so that when said first switch means is activated said primary light sour ce is selectively illuminated . . . . `4 8 0 pat., col. 8, lns. 48-52. Plaintiff is correct in noting that the word "switch" can define a device that takes its name from the function it performs. E.g., Greenberg v. Ethicon EndoSurgery, Inc., 91 F.3d 1580, 1583 (Fed. Cir. 1996) (examples: "filter, brake, clamp, screw driver or lock"). One definition of "switch" is "a device for making and breaking the con nection in an electric circuit." New Oxford American Dictionary 1709 (2d ed. 2005). N o neth eless, the general structure expressed by the word "switch" is not sufficient by itself to defeat the means-plus-function presumption. In both Cole and Envirco the claim language provided more than a term that

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expressed structure; it contained additional details about the physical structure that p erfo rm ed the claimed function. In Cole, 102 F.3d at 531, in addition to the term

"p erfo ratio n means," the claim language defined the location, "extending from . . .", and extent, "extending through . . .", of the perforation. Id. In Envirco, 209 F.3d at 1365, the claim language did not merely state the term "second baffle means" and its function, but it described the claimed baffle, "having inner surfaces . . .", and its location, "between . . .". Id. The claim language accompanying "first switch means" does not provide the additional, structure-specific details found in either Cole or Envirco. It does not give the location of the first switch or any detail about the type of switch. It provides a structurally related term associated with a function, but no additional structural details. P lain tiff disagrees, contending that the claim language in claim 1 provides the location of the "first switch means" and additional detail about it: the first switch means is located betw een the energy source and primary light source because it connects those sources. Although the first switch means connects the energy and primary light sources, this co nnectio n does not mean that the first switch means is physically located between the two sour ces or even that the elements are close in proximity. Because wires are used to transfer electricity from the energy source to the light source, the first switch means could be physically located to the left of both sources, while still connecting the sources. Plaintiff also co ntends that the claim language provides the additional detail that the switch has two

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positions, activated and deactivated, because the languages says that it can be activated. H ow ever, this is not an additional detail about the first switch means. To be a "switch" the structure, at a minimum, must have two positions, otherwise it would not be a switch. E.g., O v erh ead Door Corp. v. Chamberlain Group, Inc., 194 F.3d 1261, 1267 (Fed. Cir. 1999) ("`sw itch' connot[es] a mechanical device with different settings, such as `on' or `off'"). Saying that a switch can be activated does not provide any additional detail about the stru ctu re than the word "switch" does on its own. W h en used with the word "means," the word "switch" is not sufficient to overcome the means-plus-function presumption. Plaintiff's citation to district court cases in which the term "switch means" was found to denote sufficient structure on its own does not persuade m e to find the same. E.g., General Creation LLC v. Leapfrog Enterprises, Inc., 232 F. Supp. 2d 661 (W.D. Va. 2002) ("Because the term `switch' itself imparts structure, its use rebuts t h e presumption that § 112 ¶6, applies."). Other courts have construed the term "switch m eans" to be a means-plus-function limitation when there is no additional structure provided. E.g., Overhead Door Corp., 194 F.3d at 1271 ("Claim 5 recites a `memory selectio n second switch means being adapted to select a first position . . . and . . . a second p o sitio n .' Because this claim element utilizes the term `means' and the claim does not specify any structure or material for performing the recited function, the district court p ro perly held `memory selection second switch means' is a means-plus-function element

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un der 35 U.S.C. § 112, ¶6."). Finally, this is not a case in which the patentee appears to have misunderstood the effect of using the word "means" in the patent and carelessly added the word "means." E.g., C o le, 102 F.3d at 531 ("The drafter of claim 1 in the `239 patent was clearly enamored of the word `means' . . . the claim drafter's perfunctory addition of the word `means' did no thing to diminish the precise structural character of this element."). Instead, in some c laim s of the `480 patent, the patentee used the different variations of the term "switch m ean s," e.g., `480 pat., col. 8, lns. 48-49, 57; col. 9, lns. 2, 10, 26 and 64; col. 11, lns. 10-11 an d 20, while in others he used only the term "switch," e.g., id., col. 9, ln. 56; col. 12, ln. 13. Acco rdingly, I find that the patentee chose to use the term "switch means" to invoke a m ean s-p lu s-fu nctio n limitation. C on struing "first switch means" begins with defining its function: connecting the e n e rg y source with the primary light source, which permits selective illumination of th e primary light source. Next, I must determine what structures found in the

specification are clearly linked to the claimed function. The specification states that the first switch means 36 is a conventional vehicle parking/headlamp switch 3 8 with low/high beam selector 40 on the vehicle instrument panel. The first sw itch means 36 is of the type that has a first position for illuminating the vehicle parking lights 26 and 28, has a second position for illuminating the lo w beam lights 42 and 43 of the vehicle headlamps 14 and 16 while con tinuin g to illuminated [sic] the vehicle parking lights 26 and 28, and has a third position for illuminating the high beam lights 44 and 45 of the vehicle

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headlam ps 14 and 16 while continuing to illuminate the vehicle parking lights 2 6 and 28. `48 0 pat., col. 2, lns. 32-43. The specification provides this one embodiment of the "first sw i tch means." Thus, the structures clearly linked to performance of the claimed function are: a three position conventional vehicle parking/headlamp switch with low/high beam selector and its equivalents. Inclu din g the function of each position on the switch, as defendant proposes, would im pro perly restrict the means-plus-function limitation by including functions not explicitly fo un d in the claim. Creo Products, Inc., 305 F.3d at 1346. Accordingly, the switch function at each position, as listed in the specification, is not included in the proper construction of "first switch means."

4 . Second switch means The parties' disputes regarding "second switch means" in claims 1, 2, 9 and 16 of the `480 patent are the same as their disputes regarding "first switch means." I need not repeat the analysis of those arguments. Suffice it to say, "second switch means" is a means-plusfunction limitation for the same reasons as "first switch means": the use of the term "means" raises the means-plus-function presumption and the claims language does not provide su fficien t structure to overcome the presumption.

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As for the construction of "second switch means," the first step is determining the claim ed function. There are some slight variations in function between some of the

in dep en den t claims. According to claims 1 and 16, the claimed function is to interrupt the p rim a ry light circuit and complete the secondary light circuit by connecting the en ergy source to the secondary light source so that the secondary light source is illu m in ated and the primary light circuit is not illuminated. According to claim 2, the c la i m e d function is to interrupt the primary circuit from the energy source to the prim ary light source and complete the secondary circuit light circuit from the energy so u rce to the secondary light source. According to claim 9, the claimed function is to selectively control the illumination of the vehicle headlamp means and the accessory u n it headlamp means by connecting the energy source to the vehicle headlamp means w h e n the first switch means is activated and when the coupling means is not e le ctrica lly connecting the wiring harness to the accessory unit and by connecting the en ergy source to the accessory unit headlamp means when the first switch means is activated and when the coupling means is electrically connecting the wiring harness to the accessory unit. The specification refers to one embodiment of the "second switch means" that e n g a ges all the above functions, which all interrupt the primary light circuit and complete the secondary light circuit to illuminate the secondary light source and de-illuminate the

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p rim ary light source. It is the same embodiment referred to in my construction of "switching m eans" as used in claims 7 and 18. `480 pat., col. 4, lns. 33-36. Thus, the structures that engage in the claimed functions are first and second relays of a single pole double throw type and their equivalents. I note that how the "second switch means" is activated is an addition al element of each claim that is not part of the structure and need not be included in a proper construction of the term. Construing the claim term to include such information w ou ld be superfluous. The requirement of an activation element is present in the claim w ithout any additional construction by the court. F in ally, I note that although the construction of "second switch means" does not follow the doctrine of claim differentiation, which states that different claims should be p resu m e d to cover different inventions, this divergence is proper under the current circu m stan ces. An example of the divergence can be seen in claim 10, which is dependent fro m claim 9, and covers "[t]he wiring harness as set forth in claim 9 wherein said second switch means includes a relay." Id., col. 10, lns. 39-40. Because "second switch means" as used in claim 9 already includes first and second relays, dependent claim 10 would not cover a new invention. The doctrine of claim differentiation "is not a rigid rule but rather [ ] one of several claim construction tools." ICU Medical, Inc. v. Alaris Medical Systems, Inc., 558 F.3d 1368, 13 76 (Fed. Cir. 2009). In fact, the Court of Appeals for the Federal Circuit has explained

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th a t th e judicially developed guide to claim interpretation known as `claim d ifferen tiatio n ' cannot override the statute. A means-plus-function limitation is not made open-ended by the presence of another claim specifically claiming th e disclosed structure which underlies the means clause or an equivalent of that structure. . . . [O]ne cannot escape th[e] mandate [of § 112 ¶6] by m erely adding a claim or claims specifically reciting such structure or s t r u c tu r e s . Laitram Corp v. Rexnord, Inc., 939 F.2d 1533, 1538 (Fed. Cir. 1991). Therefore, the co n stru ctio n of "second switch means" is proper because it is a means-plus-function lim itatio n and the specification provides only one embodiment of the corresponding s t r u c tu r e s .

5 . Coupling means T he parties dispute whether the term "coupling means" as used in claims 1, 2, 7, 9 and 16 of the `480 patent is a means-plus-function limitation. The claims' use of the word "m eans" raises the presumption that the limitation is means-plus-function. Plaintiff

co nten ds that the word "coupling" provides sufficient structure to overcome the p resu m p tio n , placing the limitation outside the scope of § 112 ¶6. Plaintiff is mistaken. A ll the relevant claims provide for the same element: "a coupling means for

selectively connecting and disconnecting said accessory unit to said vehicle." E.g., `480 pat., col. 8, lns. 53-54; col. 9, lns. 6-7. As with "switch," "coupling" can refer to a device defined

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b y its function. E.g., New Oxford American Dictionary 388 (2d ed. 2005) ("a device for co n n ectin g parts of machinery"). However, the remainder of the claim language does not pro vide any additional information about the proper structure for the coupling means, other than the function of the coupling. Moreover, "coupling" needs to be narrowed to some stru ctu re because the term standing alone could encompass too many structures that do not fall in line with the invention. For example, a screw and bolt connecting two steel plates could connect and disconnect the accessory unit to the vehicle. However, it is clear from the patent that such a coupling would fall outside the scope of the invention, which intended to use the "coupling means" as a way to connect the electrical circuits of the accessory unit to the vehicle's energy source. `480 pat., col. 3, lns. 34-35. Therefore, "coupling means" is a m ean s-p lu s-fu nctio n limitation. A c c o rd in g to the claims, a "coupling means" functions to selectively connect and d iscon n ect the accessory unit to the vehicle. The only "coupling means" described in the sp ecificatio n are conventional "female and male plow plugs 60 and 78" and "female and m a le batter plugs 62 and 80." Id., col. 3, lns. 36-39. Figure 2 provides a visual

representation of these type of plugs:

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T hus, the structures clearly linked with the claimed function are conventional female and m ale plow plugs and female and male battery plugs and their equivalents. D efendan t contends that the specification's specific examples of female and male battery plugs and female and male plow plugs should be included in the construction. The specification lists the preferred embodiment of the battery plugs as (1) a two-pin plug for the m ale battery plug and a two-receptacle plug for the female battery plug and (2) a 12-pin plug fo r the male plow plug and a 12-receptacle plug for the female plow plug. `480 pat., col. 3, ln s. 45-68 and col. 4, lns. 1-8. However, those specific versions of the different plugs are not clearly linked to the claimed function. In other words, whether the plugs have 2 pins or 100 pin s, all that matters are that they are male and female and that they function to connect an d disconnect the electrical circuits of the accessory unit to the vehicle. Further, even th ou gh the specification lists the male plow plug as a 12-pin plug, the figure shows only a 6-

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p in plug. Id., col. 3, lns. 57-68 and col. 4, 1-5. The specification notes that the function of the other six pins is not explained because "they are not part of the operation of the invention." Id., col. 4, lns. 4-5. Accordingly, including the specific plugs listed in the specification would read in functions not listed explicitly in the claims.

E . The `700 Patent 1. Snowplow blade fixed to the A-frame I conclude that the term "snowplow blade fixed to the A-frame" as used in claims 1, 38 and 45 of the `700 patent does not need construction because its plain and ordinary m eaning is easily discernible from the claim language. The term is clear and nothing in the claim language or the specification requires a special definition. Therefore, the plain and ordinary meaning controls. Northern Telecom Ltd., 215 F.3d at 1295. I note that

defendan t's proposed construction seeks to impose limitations from the specification, such as a requirement that the blade be attached directly to the A-frame without any intermediate structures. Such limitations do not appear in the claims themselves and nothing suggests that the patentee was attempting to give a narrower construction to "fixed to" than the plain an d ordinary meaning of the term. Such a construction would be improper. Golight, 355 F.3d at 1331 ("[L]imitations from the specification are not to be read into the claims.").

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2 . Mounting means The parties agree that the term "mounting means" as used in claims 1 and 38 of the `70 0 patent is a means-plus-function limitation to which § 112 ¶6 applies. The first step in con struing "mounting means" is to define the claimed function. The parties do not dispute th e claimed function, which I agree is to selectively connect the A-frame to the mounting fram e for pivotal movement about a generally horizontally extending pivot axis and af fo rd removal of the A-frame and the lift frame from the mounting frame as a unit so as to leave the mounting frame on the vehicle and behind the bumper. Their dispute concerns the corresponding structures. T o find those structures, it is helpful to break down the claimed function into two parts and find the structures clearly linked to each part of the function. The first part of the claim ed function is to selectively connect the A-frame to the mounting frame for pivotal m ov em ent about a generally horizontally extending pivot axis. The specification provides o n e embodiment of structures performing this portion of the claimed function: A pair of hinge pins 80 can be inserted into the aligned pin holes 47, 78 to join the mounting lugs 42 and mounting plates 76 to afford pivotal rotation of the A-frame 22 relative to the mounting frame assembly 16 about the pivot axis 46. `70 0 pat., col. 7, lns. 48-52. (Emphasis added.) Figure 6 illustrates the relevant structures:

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T hus, the structures clearly linked to the claimed function are two lugs, each consisting of a pair of vertical plates with hinge pin holes, two plates with hinge pin holes, two hinge pins and their equivalents.

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D efendant contends that the location of the mounting lugs and plates should be in clu ded as part of the claimed structures because the location is part of the only e m bo dim en t of the claimed function. It is true that the only embodiment in the

specification, as well as all the figures, places the lugs on the mounting frame and the plates on the A-frame. E.g., id., col. 7, lns. 34-48. However, nothing in the claim language or the sp ecificatio n clearly links the location of the lugs or the plates to the claimed function. For exam ple, there is no language suggesting that pivotal movement would be hindered by placing the lugs on the A-frame instead of on the mounting frame. Therefore, including the location of the lugs and plates in the corresponding structures would not be proper. T he second part of the claimed function is to allow the A-frame and the lift frame to be removed from the mounting frame as a unit so as to leave the mounting frame on the vehicle and behind the bumper. Defendant correctly contends that the same structures associated with the first portion of the claimed function are the structures corresponding to th e second portion, but it ignores the additional structures clearly linked to the second portion. According to the specification, "the frame assembly 24 is pivotally connected to the A-frame base member 81 so that the snowplow assembly 18 and the lift frame assembly 24 can be removed from the vehicle as a unit." Id., col. 9, lns. 1-5. The lift frame's pivotal connection to the A-frame base is what permits the A-frame and lift frame to be removed as a unit.

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T he specification explains how the A-frame and lift frame are connected as follows: T he lower potions 113 of each side member 112 have fixed thereto a lift fram e mounting plate 115 having a bolt hole 116 there-through so as to align w ith the bolt holes 84 in the lift frame clevises 82 and so as to be coaxially aligned with pivot axis 46. Bolt 118 (shown only in FIG. 11) pivotally con nects lower portions 113 of side members 112 and base member 81 of Afram e 22 so that the lift frame assembly 24 is pivotable about the pivot axis 4 6 relative to the A-frame 22 . . . . Id ., col. 9, lns. 13-22. Figure 11 provides an illustration of some of the additional relevant stru ctu res not visible in Figure 6:

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T hus, the structures clearly linked to the second portion of the claimed function are two plates with bolt holes, two clevises, two bolts and their equivalents. (Neither party explains what a clevis is. However, I believe it is easier to understand how the patented inventio n functions when the ordinary meaning of the term is provided. A clevis is "a Ush ap ed or forked metal connector within which another part can be fastened by means of a bolt or pin passing through the ends of the connector." New Oxford American Dictionary 31 8 (2d ed. 2005). An illustration of a clevis further helps in understanding the structure:

http://com m on s.w ikim edia.org/w iki/File:Clevis.svg (last visited March 1, 2010).) D efendant contends that the pivotal connection between the A-frame and lift frame is not part of the claimed function and thus, the structures involved in that function are not clearly linked to the claimed function. I disagree. Connection of the A-frame and lift frame is part of the claimed function. If they were not connected, they could not be removed as a unit. Further, although a pivotal connection is not necessary to allow the structure to en gage in the claimed function, it is permissible for structures to engage in more than one function . Thus, the structures connecting the A-frame and lift frame are clearly linked to

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perm it their removal as a unit.

3. Support frame D efendant points out that plaintiff failed to propose a construction for "support fram e" as used in claim 45 of the `700 patent when the parties had their exchange of terms an d proposed constructions in October 2009. Def.'s Resp. Br., dkt. #86, at 12-13. Because p lain tiff has violated the preliminary pretrial conference order, dkt. #11 at 2, the construction that it proposed in its initial claims construction brief cannot be considered at this time. R egardless of plaintiff's proposed construction, defendant does not provide a construction of its own. Instead, it seeks to have claim 45 invalidated by contending that "support frame" is an indefinite term. The Court of Appeals for the Federal Circuit has explained that Under 35 U.S.C. § 112, claims must "particularly point[ ] out and distinctly cla im [ ] the subject matter which the applicant regards as his invention." If a claim fails to reasonably apprise one skilled in the art of the boundaries of the claim when read in light of the specification, then the claim is invalid un der § 112 for indefiniteness. 580 F.3d 1340, 1371 (Fed. Cir. 2009). Nonetheless, a patent's claims are presumed to be valid and establishing invalidity requires the party seeking to invalidate the patent claim to pro ve invalidity by clear and convincing evidence. Aero Products International, Inc. v. Intex

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R e c reatio n Corp., 466 F.3d 1000, 1015 (Fed. Cir. 2006). Thus, invalidity of a patent's claim based on indefiniteness is better dealt with at summary judgment. I will reserve ruling o n "support frame" until then.

F . The `530 Patent 1. Means for releasably connecting the lift frame to the mount frame The parties agree that the term "means for releasably connecting the lift frame to the m o un t frame" as used in claims 1 and 10 of the `530 patent is a means-plus-function lim itation to which § 112 ¶6 applies. The first step in construing the term is to define the claim ed function. The parties do not dispute the claimed function. The relevant claim lan guage provides: the lift frame including . . . means for releasably connecting the lift frame to the mount frame affording removal of the lift assembly from the mount frame as a single unit so as to leave the mount frame on the vehicle. `53 0 pat., col. 6, lns. 23-30. Accordingly, the claimed function is releasably connecting the lift frame to the mount frame affording removal of the lift assembly from the mount fra m e as a single unit so as to leave the mount frame on the vehicle. The parties' dispute lies in the corresponding structures. T h e specification sets out one embodiment of the claimed function: L ow er support 54 further includes means 82 for connecting lift assembly 30

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to mount frame 28. In the embodiment illustrated in FIG. 4, connecting m eans 82 includes a pair of U-shaped channels 84 and a pair of lugs 85 each fo r carrying a spring biased retractable pin 86 connected to the outside of each of the channels. `53 0 pat., col. 4, lns. 42-48. Figure 4 illustrates the described structures:

T hus, the structures clearly linked to the claimed function are a pair of U-shaped spaced ch an n els, a pair of lugs each carrying a spring biased retractable pin and their e q u i v a le n t s . D efendant contends that additional structures should be included in construing the term . Specifically, defendant contends that the structures associated with the mount frame

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are necessary to perform the claimed function. It is true that for the lift frame to connect t o the mount frame, the mount frame must have structures that fit with the lift frame. H o w e ver, viewing the term at issue in the context of claims 1 and 10, it is clear that "means of connecting" refers to portions included with the lift frame. Both claims 1 and 10 refer to "a snow plow assembly, comprising: . . . a mount frame . . . a lift assembly including . . . a lift frame . . . the lift frame including . . . means for releasably connecting . . . ." `530 pat., cla im s 1 and 10. Therefore, the structures associated with the mount frame are not clearly link ed to the claimed function, which is associated with only the lift frame.

2 . A pair of spaced guides tapering in an outwardly direction I conclude that the term "a pair of spaced guides tapering in an outwardly direction" as used in claim 10 of the `530 patent means two spaced guides, each tapering in a direction away from the centerline of the U-shaped channel on which it is located. The parties dispute whether both spaced guides need to taper outwardly. Plaintiff contends that they don't and defendant contends that they do. Defendant has the more persuasive p o si t i o n . N o th in g in the claim language itself allows the inference that the language "tapering in an outwardly direction" refers to only one of the pair of spaced guides. If the patentee intend ed such a meaning, he should have claimed "a pair of spaced guides at least one of which

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tapers in an outwardly direction." The most reasonable construction from reading the claim lan guage is that both guides taper in an outwardly direction. This reading has further support in the specification, which discusses "a pair of spaced guides 90, each guide tapering in an o utw a rd ly direction," `530 pat., col. 5, lns. 1-2, and the illustrations of the invention:

Plaintiff contends that the prosecution history of the `530 patent supports its con struction . However, nothing in the prosecution history changes the claim language. Plaintiff notes that an earlier version of the `530 patent contained a dependent claim 12 that s ta t e d : 12. T h e snow plow assembly of claim 6 wherein the alignment means includes a pair of spaced guides, each of the guides tapering in an outwardly direction. O lejn iczak Decl., dkt. #17, exh. B, at DD 000143. Eventually claim 12 was removed from the patent, but the language in claim 12 was reworked into what is now independent claim

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10, which no longer contains the "each of the guides" language. It is important to note that the patentee was not told to change claim 12 for validity reasons. Contrary to plaintiff's argument, removal of the "each of the guides" language does n o t support the conclusion that the "tapering in an outwardly direction" was intended to ap ply to at least one of a pair of spaced guides. A more reasonable view of the removal of the "each of the guides" language is that the phrase was removed because it was superfluous and unnecessary. In creating independent claim 10, the "each of the guides" language would no t have added anything but extra words because the phrase "a pair of spaced guides tapering in an outwardly direction" covered the same invention without the extra phrase.

3. Means for pivotally connecting the rear end of the A-frame to the lift frame T h e term "means for pivotally connecting the rear end of the A-frame to the lift fram e" as used in claims 1 and 10 of the `530 patent is a means-plus-function limitation to w hich § 112 ¶6 applies. Plaintiff does not propose a claimed function. Defendant proposes w hat I find to be the correct claimed function. The relevant claim language provides: the lift frame including means for pivotally connecting the rear end of the Afram e to the lift frame whereby the A-frame is free to rotate relative to the lift fram e. `53 0 pat., col. 6, lns. 23-26; col. 8, lns. 5-8. Accordingly, the claimed function is pivotally con n ectin g the rear end of the A-frame to the lift frame.

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T h e specification provides one embodiment of the claimed function: L ow er support 54 includes means 75 such as a pair of spaced clevises 76 for connecting the rear end 74 of A-frame 42 to lower support 54. Each side of rear end 74 of A-frame 42 includes a flange 78 having an opening, each flange pivo tally connect to one of [sic] clevises 76 by a pin 80. Id., col. 4, lns. 34-39. Figure 4, which is depicted previously in this opinion, illustrates the relevan t structures. Therefore, the structures clearly linked with the claimed function are a pair of spaced clevises and pins. As with the term "means for releasably connecting," defendant contends that a proper c o n s t ru ctio n of the term "means for pivotally connecting" should contain the connecting structures not only on the lift frame but the A-frame as well. Defendant is mistaken for the sam e reasons it was mistaken regarding "means for releasably connecting." The claimed function is limited to structures on the "lift frame." It is not reasonable to say that the lift fram e includes structures found on the A-frame. The structures on the A-frame are part of the A-frame and the structures on the lift frame are part of the lift frame. Looking at the claim language from another perspective helps express why the structures are separate. To o btain the same result, the claim could be rewritten to state, "the lift frame's means for pivo tally connecting the rear end of the A-frame to itself." In other words, the claimed fu nctio n is limited to the lift frame's use of the function. Therefore, the court's construction pro perly limits the term without including the A-frame's connecting structures.

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G . The `978 Patent 1. Generally parallel to the longitudinal axis I conclude that the term "generally parallel to the longitudinal axis" as used in claims 2 8 , 53 and 57-59 of the `978 patent does not need construction because its plain and ord inary meaning is easily discernible from the claim language. Nothing in the claim language or the specification requires a special definition. Therefore, the plain and ordinary m eaning controls. Northern Telecom Ltd., 215 F.3d at 1295. Nonetheless, I note that

defendant's proposed construction would not fit into the ordinary meaning of the term. D efendant contends that a proper construction of the term should include the lim itation "without rotation in a direction perpendicular to that axis." It is helpful to read the term in context, which includes the following language: o n e of said mount frame and said snowplow frame having first and second arm s and the other of said mount frame and snowplow frame having first and seco n d receivers, said first and second receivers receiving said first and second arm s, respectively upon relative movement therebetween in a direction generally parallel to the longitudinal axis of the vehicle. E.g., `978 pat., col. 10, lns. 15-21; col. 14, lns. 8-14. "Generally parallel to the longitudinal axis" describes the direction of movement between the first and second arms and first and secon d receivers of two different frames that are being connected. The specification provides an example of this purpose of this movement: For both attaching the snowplow assembly 12 to and detaching the snowplow

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assem bly 12 from the mount assembly 14 a force should be applied to the lift fram e 22, such as on traverse element 44, in the direction of the mount assem bly 14 as latch lever 160 is rotated. Such movement facilitates alignm ent of the latch pins 102, 104 with the holes 94 in the arms 92. Id., col. 7, lns. 21-27. Thus, the movement in a direction "generally parallel to the

lon gitudinal axis" of the vehicle is to facilitate alignment of the latch pins with the holes in the arms so that the mount frame and snowplow frame can be connected. N either the claim language nor the specification permits the inference that "generally parallel to the longitudinal axis" means "without rotation in a direction perpendicular to that axis." First, the claim language uses the word "generally" which leaves open the possibility that the movement will occur in a direction other than perfectly parallel to the longitudinal axis. Second, it would defeat the purpose of the invention to construe the term as excluding a n y movement in a direction perpendicular to the longitudinal axis of the vehicle. In alignin g the latch pins with the arm holes, it is possible that if the arm holes were slightly below the latch pin alignment, force on the snowplow assembly could tilt the arms upward, that is, perpendicular to the longitudinal axis of the vehicle, while moving the arms into the receivers to align the holes with the pins. Finally, defendant fails to point to any language that prohibits perpendicular movement. Thus, the claim language is broad enough to include some movement in a direction perpendicular to the longitudinal axis of the vehicle. D efendant's proposed meaning would prevent such movement, making it improper.

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H . Scheduling Order U n d er the preliminary pretrial conference order, dkt. #11, the parties' disclosures of liab ility experts were due February 26, 2010, with responses due March 26, 2010. The d ead lin e for filing dispositive motions is April 12, 2010. Because this claims construction opinion and order affects any expert disclosures and dispositive motions involve expert disclosur es, those three deadlines will be extended as follows: (1) initial disclosure of liability exp erts are due March 22, 2010; (2) responsive reports are due April 19, 2010; and (3) d isp o sitive motions