UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD

Transcription

1 UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD MEYER PRODUCTS, LLC. Petitioner v. DOUGLAS DYNAMICS, LLC. Patent Owner Case IPR2015- U.S. Patent No. 6,928,757 PETITION FOR INTER PARTES REVIEW OF CLAIMS OF U.S. PATENT NO. 6,928,757 to Bloxdorf et al. UNDER 35 U.S.C. 311 and 37 C.F.R Mail Stop PATENT BOARD Patent Trial and Appeal Board US Patent and Trademark Office PO Box 1450 Alexandria, Virginia

2 TABLE OF CONTENTS I. MANDATORY NOTICES PURSUANT TO 37 C.F.R II. RELATED MATTERS... 1 III. CERTIFICATION OF GROUNDS FOR STANDING... 2 IV. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED... 2 A. Prior Art Patents and Printed Publications... 2 B. Grounds for Challenge... 3 V. OVERVIEW OF THE 757 PATENT... 4 A. Description of the Invention of the 757 Patent... 4 B. Summary of the Prosecution History of the 757 Patent... 5 VI. CLAIM CONSTRUCTION... 8 VII. IDENTIFICATION OF HOW CHALLENGED CLAIMS 1, 4-7 and ARE UNPATENTABLE A. Claims 1, 4-7, and 18 are Anticipated by Pruss Under 35 U.S.C B. Claims 18 and 6 are Anticipated by Keeler Under 35 U.S.C C. Claims 1, 4-7, and 18 are Obvious Over Pruss and Kost or Watson Under 35 U.S.C. 103(a) Claims 1, 4-7 and 18 of the 757 patent are obvious over Pruss in view of US Patent No. 6,354,024 to Kost Claims 1, 4-7 and 18 of the 757 patent are obvious over Pruss in view of 5,125,174 to Watson D. Claims 1, 4-7, and 18 are Obvious over Coates and Hetrick, Kost, or Watson under 35 U.S.C. 103(a) Claims 1, 4-7, and 18 of the 757 patent are obvious over Coates in view of Hetrick Claims 1, 4-7, and 18 of the 757 patent are obvious over Coates in view of Kost i

3 3. Claims 1, 4-7, and 18 of the 757 patent are obvious over Coates in view of Watson VIII. CONCLUSION ii

4 LIST OF EXHIBITS Exhibit No. Exhibit Description 1001 U.S. Patent No. 6,928,757 ( the 757 patent ) 1002 U.S. Patent No. 2,139,625 ( Pruss ) 1003 U.S. Patent No. 2,242,472 ( Keeler ) 1004 U.S. Patent No. 6,354,024 ( Kost ) 1005 U.S. Patent No. 3,605,906 ( Coates ) 1006 U.S. Patent No. 5,125,174 ( Watson ) 1007 U.S. Patent No. 4,236,329 ( Hetrick ) 1008 First Office Action issued September 9, Response to First Office Action filed March 9, Second Office Action issued May 28, Response to Second Office Action filed November 29, Reproduction of Figures 2A and 3A of the 757 Patent 1013 Reproduction of Figures 1, 2, and 11 of Watson 1014 Reproduction of Figures 1, 5, 10, 13, and 20 of Kost 1015 Reproduction of Figures 1-4, 6-7, and of Pruss 1016 Reproduction of Figures 1, 17, and 18 of Keeler; Close-up view of Figure 17, labeled Figure 17A 1017 Reproduction of Figure 1 of Coates 1018 Reproduction of Figures 1, 2, and of Hetrick; Close-up view of Figure 2, labeled Figure 2A 1019 Declaration of David Scott Smith in Support of Petition for Inter Partes Review iii

5 I. MANDATORY NOTICES PURSUANT TO 37 C.F.R Real Party-in-Interest: Meyer Products, LLC. ( Petitioner ) Counsel: Lead Counsel: John M. Skeriotis (Registration No. 43,129) Backup Counsel: Roger D. Emerson (Registration No. 33,169); Timothy D. Bennett (Registration No. 42,312); Sergey Vernyuk (Registration No. 71,283); and, Andrew S. Curfman (Registration No. 72,942). Service Information: iplaw@etblaw.com Emerson Thomson Bennett, LLC Phone: Akron-Peninsula Rd. Fax: Akron, OH II. RELATED MATTERS Douglas Dynamics, LLC. (hereinafter DDI ) is the owner US Patent No. 6,928,757 ( the 757 patent ) (Ex. 1001) and has asserted the 757 patent against Petitioner in the United States District Court for the Western District of Wisconsin, Douglas Dynamics, LLC vs. Meyer Products, LLC, Case No. 3:14-cv The 757 patent claims priority to Application No. 09/684,269, now US Patent No. 6,526,677 ( the 677 patent ) which has not been asserted against the Petitioner in the district court case. The 677 patent is not being challenged by this Petition. 1

6 III. CERTIFICATION OF GROUNDS FOR STANDING Petitioner certifies pursuant to Rule (a) that the patent for which review is sought is available for inter partes review and that Petitioner is not barred or estopped from requesting an inter partes review challenging the patent claims on the grounds identified in this Petition. IV. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED Pursuant to Rules 42.22(a)(1) and (b)(1) (2), Petitioner challenges claims 1, 4-7, and 18 of the 757 patent. The 757 patent claims priority to the 677 patent, which was filed on October 6, 2000 ( the priority date ). Petitioner requests that claims 1, 4-7, and 18 of the 757 patent be found unpatentable. Prior Art Patents and Printed Publications Petitioner relies upon the following patents and printed publications: a. Ex US Patent No. 2,139,625 to Pruss ( Pruss ), issued on December 6, 1938 and available as prior art under 35 U.S.C b. Ex US Patent No. 2,242,472 to Keeler ( Keeler ), issued on May 20, 1941 and available as prior art under 35 U.S.C c. Ex US Patent No. 6,354,024 to Kost ( Kost ), issued on March 12, 2002 and available as prior art under 35 U.S.C d. Ex US Patent No. 3,605,906 to Coates ( Coates ), issued on September 20, 1971 and available as prior art under 35 U.S.C

7 e. Ex US Patent No. 5,125,174 to Watson ( Watson ), issued on June 30, 1992 and available as prior art under 35 U.S.C f. Ex US Patent No. 4,236,329 to Hetrick ( Hetrick ), issued on December 2, 1980 and available as prior art under 35 U.S.C Citations to Exhibits without predetermined column numbers will take the following format: (Exhibit Number, Page Number: Column (1 for left column, 2 for right column): Line Number) Citations to exhibits with predetermined column numbers will take the following format: (Exhibit Number, Column: Line Number) Grounds for Challenge Petitioner requests cancellation of challenged claims 1, 4-7, and 18 under the following statutory grounds: a. Claims 1, 4-7, and 18 are unpatentable under 35 U.S.C. 102 as anticipated by Pruss (Ex. 1002). b. Claims 18 and 6 are unpatentable under 35 U.S.C. 102 as anticipated by Keeler (Ex. 1003). c. Claims 1, 4-7, and 18 are unpatentable under 35 U.S.C. 103 as obvious over Pruss (Ex. 1002) and Kost (Ex. 1004) or Watson (Ex. 1006). 3

8 d. Claims 1, 4-7, and 18 are unpatentable under 35 U.S.C. 103 as obvious over Coates (Ex. 1005) and Hetrick (Ex. 1007), Kost (Ex. 1004), or Watson (Ex. 1006). V. OVERVIEW OF THE 757 PATENT Description of the Invention of the 757 Patent To assist in understanding the 757 patent components and operation, Figs. 2A and 3A of the 757 patent are reproduced in Ex with identifying arrows added. Fig. 2A is a side view of a snowplow assembly in the process of being attached to a vehicle. Fig. 3A is a top view of the snowplow assembly with various components removed. The 757 patent discloses a snowplow assembly 16 including three principal elements: 1 a lift frame 46, a trunnion 48, and an A-frame 50. To one end of the A- frame 50 is attached snowplow blade 74. The opposite end of the A-frame 50 is attached to the trunnion 48 with bolt 66. The lift frame 46 supports lift cylinder 59 which is used to lift/raise the snow plow blade 74 as will be discussed below. The trunnion 48, seen best in Fig 3A, is a transversely extending bar that is used with two pivoting motions: (1) motion about a transverse, horizontal pivot axis 64 defined by the trunnion 48; and, (2) motion about a longitudinal, horizontal pivot 1 So called by DDI, Ex. 1001, 4:

9 axis 68 defined by the bolt 66. These pivoting motions will be discussed below. To attach the snowplow assembly 16 to vehicle 14, the vehicle is driven, as shown in Fig. 2A, toward the snowplow assembly 16 such that horns 42 are positioned within receivers 22. Stand assemblies 84 are then adjusted out of their support or parked condition, the wiring harness (not shown) of the snowplow is connected to the wiring harness (not shown) of the vehicle 14, and the snowplow assembly 16 is then ready for use by the operator of the vehicle 14. In use, to lift/raise the snowplow blade 74, lift cylinder 59 is extended to lift the A-frame 50 (and thus the snowplow blade 74) away from the ground surface as the trunnion 48 pivots about the transverse, horizontal pivot axis 64. During plowing operation of the snow plow blade 74, should the ground surface being plowed become transversely (side-to-side) uneven, the A-frame 50 (and thus the snowplow blade 74) will pivot with respect to the trunnion 48 about the longitudinal, horizontal pivot axis 68. Summary of the Prosecution History of the 757 Patent Patent Application No. 10/339,116, which is now the 757 patent, was filed on January 9, 2003 and assigned to DDI. Claim 32, now challenged claim 1, requires a trunnion pivotally connected to said lift frame for pivoting movement about a transverse, horizontal axis. 2 Many other claims have the same or similar 2 Ex. 1001, Claim 1. 5

10 requirements. In a first Office Action dated September 9, 2003, the Examiner rejected all claims under 35 U.S.C. 102(b) as clearly anticipated by Watson et al. 3 To assist in understanding Watson s components and operation, Figs. 2 and 11 from Watson are reproduced in Ex with identifying arrows added. Fig. 2 is a side view of a snowplow assembly attached to a vehicle. Fig. 11 is a top view of the snowplow assembly with various components removed. With reference to Fig. 2, Watson discloses a snowplow assembly 10 including an A-frame 22. A snowplow blade 20 is attached to one end of the A-frame 22. The opposite end of the A-frame 22 is pivotally attached to the mounting frame assembly 16, as seen best in Fig. 11, with two removable hinge pins 80, 80 positioned on opposite sides of the A-frame 22. The A-frame 22, and thus the snowplow blade 20, is raised from the ground surface by actuator means 110. As the A-frame 22 and snowplow blade 20 are raised, the A-frame 22 pivots about the pins 80, 80 and thus about transverse, horizontal axis Though the Examiner s comments were terse regarding the rejection based on Watson, the only components of Watson that can possibly meet the trunnion pivotally connected to said lift frame for pivoting movement about a transverse, 3 Ex. 1008, Pg. 2. (Pg. 3 of.pdf document). 4 Watson is discussed in more detail infra at Section VII (C). 6

11 horizontal axis requirement is one of the hinge pins 80. DDI s response, dated March 9, 2004, traversed the 102 rejection by distinguishing the rejected claims over Watson. Regarding claim 32, now challenged claim 1, DDI stated Watson does not disclose or suggest the claimed trunnion 5 As a result, DDI should be estopped from an interpretation of trunnion that is a pivot pin as disclosed in Watson. In a second Office Action dated May 28, 2004, the Examiner rejected numerous claims under 35 U.S.C. 102(e) as anticipated by Kost. 6 To assist in understanding Kost s components and operation, Figs. 1, 10 and 5 from Kost are reproduced in Ex with identifying arrows added. Fig. 1 is a side view of a snowplow assembly attached to a vehicle. Fig. 10 is a perspective view of a blade mount assembly with the snowplow removed. Fig. 5 is an enlarged cross-sectional view taken along lines 5-5 in Fig The Examiner argued that Kost s pin 290 met the claimed trunnion. 8 DDI s response, dated November 29, 2004, traversed the 102 rejection arguing that Kost 5 See Ex. 1009, Pgs (Pgs of.pdf document); the full sentence is: Watson et al. does not disclose or suggest the claimed trunnion or A-frame which pivots about a longitudinal, horizontal axis. Because DDI s trunnion 48 cannot pivot about the longitudinal, horizontal axis 66 (it can only pivot about the transverse, horizontal axis 64), the portion of the quoted sentence after the word or can only apply to the A-frame 50 which indeed pivots about the longitudinal, horizontal axis Ex. 1010, Pgs. 2-3 (Pgs. 3-4 of.pdf document). 7 Kost is discussed in more detail infra at Section VII (C). 8 Ex at Pg. 2 (Pg. 3 of.pdf document). 7

12 did not disclose or suggest the claimed trunnion 9 As a result, once again DDI should be estopped from an interpretation of trunnion that is a pivot pin as disclosed in Kost. On February 24, 2005, a Notice of Allowance was issued and the 757 patent ultimately issued on August 16, The Examiner did not provide a Notice of Allowability setting forth any reasoning for allowing the 757 patent claims. VI. CLAIM CONSTRUCTION Pursuant to Rule (b), the terms of an unexpired claim is to be given its broadest reasonable construction in light of the specification of the patent in which it appears. Evidence of the broadest reasonable construction includes any statements made by the patent owner which were filed with a Federal court or with the US Patent and Trademark Office ( USPTO ) in which the patent owner took a position on the scope of any claim of the 757 patent. A-frame : DDI states of the illustrated A-frame: The A-frame 50 comprises a back a back bar 70 and a pair of side bars 72 arranged in a triangular, or A configuration. 10 In a general statement, however, DDI states: while the term 9 Ex. 1011, Pg. 26 (Pg. 25 of.pdf document); the full sentence is: Kost et al. does not disclose or suggest the claimed trunnion or A-frame which pivots about a longitudinal, horizontal axis. Because DDI s trunnion 48 cannot pivot about the longitudinal, horizontal axis 66 (it can only pivot about the transverse, horizontal axis 64), the portion of the quoted sentence after the word or can only apply to the A-frame 50 which indeed pivots about the longitudinal, horizontal axis Ex. 1001, 4:

13 A-frame has been used herein, it is to be understood that other configurations of frames other than A s may be substituted therefore in the practice of the present invention and yet still be within the scope thereof. 11 Thus, the broadest reasonable interpretation of the term A-frame in light of the specification is any frame structure of any shape. being adapted to be attached to and detached from a vehicle as a single assembly : As used in challenged claim 18, it is noted that these terms add no additional structure. Thus, the broadest reasonable interpretation of these terms is that the components listed before being are capable of being attached to and detached from a vehicle together as a unit. all being attachable to and detachable from a vehicle as one assembly : As used in challenged claims 1, 4, and 6, it is noted that these terms add no additional structure. Thus, the broadest reasonable interpretation of these terms is that the components listed before all are capable of being attached to and detached from a vehicle together as a unit. Lift Frame : These terms are well known by persons of skill in the art to mean frame structure that is used to lift (raise and sometimes lower) a snow plow. Lift frames often support a lift cylinder (or other motion generating device, see below) that provides the force to lift/raise a snow plow from a ground surface. 11 Id. at 8:

14 Longitudinal, Horizontal Axis : These terms are well known by persons of skill in the art to mean a straight line that: (1) extends in the direction of travel of the vehicle (longitudinal) carrying a snow plow; and, (2) is parallel with the ground surface (horizontal) upon which the vehicle travels. A longitudinal, horizontal axis is perpendicular to a transverse, horizontal axis (discussed below). Motion Generating Device : These terms are well known by persons of skill in the art to mean a device that causes something else to move. Transverse, Horizontal Axis : These terms are well known by persons of skill in the art to mean a straight line that: (1) extends in the direction perpendicular to travel of the vehicle (transverse) carrying a snow plow; and, (2) is parallel with the ground surface (horizontal) upon which the vehicle travels. A transverse, horizontal axis is perpendicular to a longitudinal, horizontal axis. Trunnion : DDI states, The trunnion 48 comprises a transversely extending bar which is pivotable about the prior-mentioned first transversely extending horizontal axis 64 relative to the lift frame During prosecution, DDI disclaimed a pivot pin as being a trunnion. 13 Thus, the broadest reasonable interpretation of the term trunnion in light of the specification and prosecution history is: a bar that: (1) has length in a side-to-side (transverse) direction; (2) pivots 12 Ex. 1001, 4: See supra Section V(B) 10

15 about a transverse, horizontal axis (discussed above); (3) pivots relative to the lift frame (discussed above); and, (4) is not a pivot pin. VII. IDENTIFICATION OF HOW CHALLENGED CLAIMS 1, 4-7 and 18 ARE UNPATENTABLE Pursuant to Rule (b)(4) (5), this section demonstrates that the challenged claims are unpatentable. Claims 1, 4-7, and 18 are Anticipated by Pruss Under 35 U.S.C. 102 US Patent No. 2,139,625 to Pruss ( Pruss ) was filed on November 2, 1936 and issued as a patent on December 6, Pruss was not cited in the prosecution history of the 757 patent and thus was not considered by the Examiner who granted the 757 patent. To assist in understanding Pruss components and operation, various figures from Pruss are reproduced in Ex with identifying arrows added. Fig. 1 is a side view and Fig. 2 is a top view of a snowplow assembly attached to a vehicle. Pruss snowplow assembly includes a plow blade 31 mounted to a vehicle 11. A motion generating device, hydraulic ram 36, is used to raise/lift the plow blade 31. The plow blade 31 is mounted to the forward end of an A-frame which includes struts 26, 26 and transverse bar 30. The motion generating device 36 is supported to a lift frame which includes tower 20 and tie rods 21, 21. Operation of the motion generating device 36 raises/lifts the plow blade 31 and A-frame 26 with respect to 11

16 the lift frame 20. Pruss discloses different embodiments for how the A-frame (and thus the plow blade 31) is attached to the vehicle. One embodiment, hereinafter referred to as Pruss 1, is shown in Figs which are reproduced in Ex with identifying arrows added. Fig. 10 is a sectional top view of the trunnion and other components. Fig. 11 is a side view taken along lines of Fig. 10 and Fig. 12 is an end view taken along lines of Fig. 10. For Pruss 1, A-frame struts 65, 65 have replaced A-frame struts 26, 26 but their function in supporting the plow blade is the same. Pruss 1 includes bolster/trunnion 55 which has bars 62, 62 attached to each end. A-frame includes struts 65, 65 and slides 63, 63 which are fixed to the struts. Trunnion 55 has a hole 60 that extends through the trunnion 55 and that receives bolt 59. Hole 60 is larger than the bolt 59 and shaped to permit the trunnion 55 to rotate about its axis through an arc of about 30 degrees or less. 14 The trunnion s axis is shown with axis line B- B. The trunnion 55 is also laterally tiltable about the pin 59 through an arc of about 10 to 15 degrees on either side of horizontal. 15 In use, when the motion generating device 36 is operated, the plow blade 31, A-frame 65 and trunnion 55 pivot, with respect to lift frame 20, about transverse, 14 Ex. 1002, Pg. 4:2: Id. at Pg. 4:2:

17 horizontal axis B-B. During plowing operation of the plow blade 31, should the ground surface being plowed become transversely (side-to-side) uneven, the A- frame 65 (and thus the plow blade 31) will pivot with respect to the trunnion 55 about longitudinal, horizontal pivot axis C-C defined by bolt 59. Another embodiment of Pruss for attaching the A-frame (and thus the plow blade 31) to the vehicle, hereinafter referred to as Pruss 2, is shown in Figs. 3, 4, 6 and 7 which are reproduced in Ex with identifying arrows added. Fig. 3 is a top sectional view taken along line 3-3 of Fig. 1. Fig. 4 is a sectional view taken along line 4-4 of Fig. 3. Fig. 6 is an enlarged fragmentary perspective view showing the bolt about which the trunnion pivots about a longitudinal axis. Fig. 7 is a sectional end view taken along line 7-7 of Fig. 2. Pruss 2 includes bolster/trunnion 18 which has discs 22, 22 attached to each end. Each disc 22 is received in a bearing member 23. A-frame includes struts 26, 26 and bars 25, 25 which are fixed to the struts. Trunnion 18 has a hole, seen best in Fig. 7, that receives a bushing 17 that receives bolt 16. Trunnion 18 is able to tilt in a vertical plane about the pin 16 through an arc of about 10 to 15 degrees on either side of horizontal. 16 In use, when the motion generating device 36 is operated, the plow blade 31 and A-frame 26 pivot, with respect to lift frame 20, about transverse, horizontal axis 16 Id. at Pg. 2:2:

18 D-D, identified in Fig. 3. During plowing operation of the plow blade 31, should the ground surface being plowed become transversely (side-to-side) uneven, the A- frame 26 (and thus the plow blade 31) and the trunnion 18 will pivot about longitudinal, horizontal pivot axis E-E, identified in Figs. 6 and 7, defined by bolt 16. Now considering both Pruss 1 and Pruss 2, the trunnion 55/18, lift frame 20, A-frame 65/25, plow blade 31, and motion generating device 36 can be rapidly and easily attached and detached from a vehicle. 17 The frame of Pruss is secured to the chassis of a vehicle by way of bolts, most easily seen in Figs. 1 and 6. The removal of these bolts would detach the trunnion 55/18, lift frame 20, A-frame 65/25, plow blade 31, and motion generating device 36 from the vehicle as a single/one assembly. Furthermore, connection of these same bolts would attach the components just listed to the vehicle again as a single assembly. As a result, Pruss 1 and Pruss 2 both meet the claim requirements of all being attachable to and detachable from a vehicle as one assembly and being adapted to be attached to and detached from a vehicle as a single assembly. The following claim chart demonstrates on an element-by-element basis how Pruss fully discloses the subject matter of challenged claims 1, 4-7, and 18 of the 757 patent: 17 See e.g. Ex. 1002, Pg. 4:1:

19 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) Claim 1.a. A snowplow assembly Pruss 1 and 2: This invention relates comprising: to plows which are attached to and driven by a vehicle, especially to road plows, such as snow plows (Ex. 1002, Pg. 1:1;1-5) 1.b. a lift frame; Pruss 1 and 2: A rigid tower 20 is mounted on the abutment plates 13-13, braced by tie rods 21-21, and provided with resilient supporting means and hoisting means (Ex. 1002, Pg. 2:2:71-74) 1.c. a trunnion Pruss 1: a circular transverse bolster 55 rotatably mounted in slides (Id. at Pg. 4:2:25-27) 1.d. pivotally connected to said lift frame for pivoting movement about a transverse, horizontal axis; 1.e. an A-frame Pruss 2: a tiltable bolster 18, located between the bars 14, and extending through notches 13a, cut in the plates (see Figures 6 and 7). (Ex. 1002, Pg. 2:2:52-58) Pruss 1: bolster 55 rotatably mounted in slides 56-56' (Ex. 1002, Pg. 4:2:26-27) Pruss 1: The bolster 55 may be retained by means of a pin or trunnion bolt 59 extending between the bars and through an elongated hole 60 in the bolster 55, the hole being shaped to permit the bolster to rotate about its axis through an arc of about 30 degrees or less. (Id. at Pg. 4:2:34-39) Pruss 1: Struts 65-65' (corresponding to the struts 26-26' shown in Figures 1 to 7) are fixedly secured to the slides 63, and form the sides of the plow frame. (Id. at Pg. 4:2:64-67) 15

20 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) Pruss 2: Fixedly secured to the bars 25 (one on each end of the bolster 18) is a pair of forwardly extending struts forming the side members of the plow supporting frame. (Ex. 1002, Pg. 3:1:11-14) 1.f. having a plow blade on a forward end and 1.g. being pivotally connected on a rearward end to said trunnion for pivoting movement about a longitudinal, horizontal axis; and Pruss 1 and Pruss 2: The struts may be suitably reinforced against buckling, and provided with a transverse bar 30. (Id. at Pg. 3:1:24-26) Pruss 1 and Pruss 2: The forward ends of the struts are curved to fit the rear surface of a plow blade 31, to which they may be fixedly secured (Ex. 1002, Pg. 3:1:26-28) Pruss 1: The bolster is laterally tiltable about the pin 59 through an arc of about degrees on either side of horizontal. (Id. at Pg. 4:2:39-42) Pruss 2: The notches have vertical dimensions to permit the bolster 18 to tilt in a vertical plane about the pin 16 through an arc of about 10 to 15 degrees on either side of horizontal. (Ex. 1002, Pg. 2:2:58-62) 1.h. a motion generating device Pruss 2: If, for example, the truck is tilted laterally with respect to the runners or the frame, the frame is free to turn about a substantially longitudinal axis (Id. at Pg. 3:2:22-25) Pruss 1 and Pruss 2: A hydraulic or oil ram 36 is suspended from the tower and secured to ribs (Ex. 1002, Pg. 3:1:40-41) 16

21 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) 1.i. for effecting relative movement Pruss 1 and Pruss 2: The ram and its between said A-frame and lift frame attaching means are so constructed as for pivoting movement about the to permit the frame to be tilted transverse, horizontal axis; upwardly through an angle of about 30 degrees above horizontal. (Ex. 1002, 1.j. said lift frame, trunnion, A-frame and motion generating device all being attachable to and detachable from a vehicle as one assembly. Claim 4.a. A snowplow assembly comprising: 4.b. a lift frame; 4.c. a trunnion connected to said lift frame 4.d. an A-frame 4.e. having a plow blade on a forward end and 4.f. being connected on a rearward end to said trunnion; and 4.g. a motion generating device 4.h. for effecting relative movement between said A-frame and lift frame; 4.i. said lift frame, trunnion, A-frame and motion generating device all being attachable to and detachable from a vehicle as one assembly; 4.j. said lift frame, trunnion and A- frame being pivotally connected in such a manner that said A-frame can pivot relative to said lift frame about a transverse, horizontal axis Pg. 3:1:54-57) Pruss 1 and Pruss 2: It will be noted that the frame is very rapidly and easily attached to and removed from the vehicle. If desired, the plates may be left on the vehicle (Ex. 1002, Pg. 4:1:31-34) See supra Claim 1.a. See supra Claim 1.b. See supra Claims 1.c.; 1.d. See supra Claim 1.e. See supra Claim 1.f. See supra Claim 1.g. See supra Claim 1.h. See supra Claim 1.i. See supra Claim 1.j. See supra Claims 1.d.; 1.i. Pruss 2: Fixedly attached to the end of the bolster 18 is a circular disc or journal 22, revolvably housed in a bearing member 23. (Ex. 1002, Pg. 3:1:2-5) 17

22 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) Pruss 2: balance the weight of the frame and plow when the same are swung upwardly about the journals 22 to place the plow out of operation (Id. at Pg. 3:1:44-47) 4.k. as well as can pivot relative to said lift frame about a longitudinal, horizontal axis. Claim 5.a. The snowplow assembly of claim 4 wherein 5.b. said trunnion is pivotally connected to said lift frame for pivoting motion about a transverse, horizontal axis 5.c. and said A-frame is pivotally connected to said trunnion for pivoting motion about a longitudinal, horizontal axis. Claim 6.a. A snowplow assembly comprising: 6.b. a lift frame; 6.c. a trunnion connected to said lift frame 6.d. an A-frame 6.e. having a plow blade on a forward end and 6.f. being connected on a rearward end to said trunnion; and 6.g. a motion generating device 6.h. for effecting relative movement between said A-frame and lift frame; 6.i. said lift frame, trunnion, A-frame and motion generating device all being attachable to and detachable from a vehicle as one assembly; 6.j. said lift frame, trunnion, A-frame and plow blade being pivotally See supra Claims 1.e.-1.g. See supra Claim 4.a. See supra Claims 4.c.; 4.j. See supra Claim 4.k. See supra Claim 1.a. See supra Claim 1.b. See supra Claims 1.c.; 1.d. See supra Claim 1.e. See supra Claim 1.f. See supra Claim 1.g. See supra Claim 1.h. See supra Claim 1.i. See supra Claim 1.j. See supra Claims 1.d.; 1.i.; 4.j. 18

23 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) connected in such a manner that said plow blade can pivot relative to said lift frame about a transverse, horizontal axis 6.k. as well as can pivot relative to said See supra Claims 1.e.-1.g. lift frame about a longitudinal, horizontal axis. Claim 7.a. The snowplow assembly of See supra Claim 6.a. claim 6 wherein 7.b. said trunnion is pivotally See supra Claims 6.c.; 6.j. connected to said lift frame for pivoting motion about a transverse, horizontal axis 7.c. and said A-frame is pivotally See supra Claim 6.k. connected to said trunnion for pivoting motion about a longitudinal, horizontal axis. Claim 18.a. A snowplow assembly See supra Claim 1.a. comprising: 18.b. a lift frame; See supra Claim 1.b. 18.c. a plow blade, 18.d. said plow blade being pivotal relative to said lift frame about a longitudinal, horizontal axis; and 18.e. a motion generating device 18.f. for effecting relative movement between said lift frame and said plow blade; 18.g. said lift frame, plow blade and motion generating device being adapted to be attached to and detached from a vehicle as a single assembly. See supra Claim 1.f. See supra Claims 1.f; 1.g. See supra Claim 1.h. See supra Claim 1.i. See supra Claim 1.j. Claims 18 and 6 are Anticipated by Keeler Under 35 U.S.C. 102 US Patent No. 2,242,472 to Keeler ( Keeler ) was filed on June 23, 1938, and issued as a patent on May 20, Keeler was not cited in the prosecution history 19

24 of the 757 patent and thus was not considered by the Examiner who granted the 757 patent. To assist in understanding Keeler s components and operation, various figures from Keeler are reproduced in Ex with identifying arrows added. Fig. 1 is a side view of a vehicle to which a snowplow assembly is attached. Fig. 17 is a top view of a snowplow assembly and Fig. 18 is a side view of the snowplow assembly shown in Fig. 17. Fig. 17a, not a separate figure in Keeler, is simply a close-up view of the middle portion of Fig. 17. Keeler s snowplow assembly includes, as shown in Figs. 17 and 18, a plow blade 146 supported to one end of an A-frame 140. A-frame 140 is attached to frame 33, shown in Fig. 1, which is attached to vehicle 20. A motion generating device, piston 86, seen best in Fig. 18, is used to raise/lift the A-frame 140 and thus plow blade 146. The motion generating device 86 is supported to a lift frame which includes uprights 57, 57. Operation of the motion generating device 86, raise/lifts the plow blade 146 and A-frame 140 with respect to the lift frame 57 as the A-frame 140 pivots about pivot pins 67, 67. The front part 144 of the A-frame 140 is pivotally connected to the back part 141 about pivot pin 145. Pivot pin 145 is visible in Figs. 17 and 18 but is seen best in close up in Fig. 17a. In use, to lift/raise the snowplow blade 146, motion generating device 86 is extended to lift the A-frame 144 (and thus the snowplow blade 146) away from the 20

25 ground surface as they pivot about the transverse, horizontal pivot axis F-F, shown in Fig. 17, defined by pivot pins 67, 67. During plowing operation of the snow plow blade 146, should the ground surface being plowed become transversely (side-toside) uneven, the front part 144 of the A-frame 140 (and thus the snowplow blade 146) will pivot with respect to the back part 141 about a longitudinal, horizontal pivot axis G-G, shown in Figs 17 and 17a, defined by pivot pin 145. As was the case with Pruss, 18 the challenged claims require that various components of the snowplow assembly have the ability to be attached and detached as a single/one assembly. Keeler states to provide for the attaching of a snow plow or other scraper blade to the tractor 20 so as to operate ahead thereof, I provide a main frame Keeler s trunnion substitute, pivot pins 67, 67 (see below), lift frame 57, A-frame 140, plow blade 146, and motion generating device 86 are all supported to the main frame 33 (as discussed above) and thus are all capable of being attached to and detached from a vehicle as a single/one assembly. Regarding claim 18 of the 757 patent, Keeler discloses every claimed element, as described above. Regarding claim 6 of the 757 patent, Keeler lacks only the claimed trunnion. In the event that it is determined that the term trunnion should be interpreted more 18 Discussed supra Section VII (A). 19 Ex. 1003, Pg. 1:2:

26 broadly than discussed above and include one or more pivot pins it is noted that Keeler s pivot pins 67, 67 would then meet the claimed trunnion and thus Keeler would also anticipate and invalidate claim 6. The following claim chart demonstrates on an element-by-element basis how Keeler fully discloses the subject matter of challenged claims 18 and, with a broader interpretations of trunnion, claim 6 of the 757 patent: 757 Patent Claims 6 and 18 Keeler (Ex. 1003) Claim 18.a. A snowplow assembly This invention relates to a new and comprising: improved type of snow plow (Ex. 1003, Pg. 1:1:1-2) 18.b. a lift frame; there extends upwardly from the angles 56 a pair of pivotally attached uprights 57, 57 formed of angle members The tops of the uprights 57 are rigidly attached by a cross-piece 59 in the form of an angle member (Ex. 1003, Pg. 2:1:47-54) 18.c. a plow blade, where the snow plow 146 (Ex. 18.d. said plow blade being pivotal relative to said lift frame about a longitudinal, horizontal axis; and , Pg. 4:2:23) Pivotally attached to said rear part 141 of the auxiliary frame 140 is a front part 144, the attachment being effected along a central horizontal longitudinal axis by a pivot pin 145 This pivot pin 145 provides for relative movement of the front and rear parts 144 and 141, about a horizontal longitudinally extending axis (Ex. 1003, Pg. 4:2:15-22) whenever the front part 144 of the auxiliary frame 140 is in any position other than horizontal, a slight tilting movement about the axis of pin 145 is

27 757 Patent Claims 6 and 18 Keeler (Ex. 1003) required to maintain the blade 147 of said snow plow 146 in a horizontal position. (Id. at Pg. 4:2:25-30) 18.e. a motion generating device To provide for the pivotal adjustment of the auxiliary frame 63 with respect to the main frame 33 I provide at each side of the auxiliary frame 63 a power operated adjusting mechanism which is preferably in the form of an expansible hydraulic piston motor 86. (Ex. 1003, Pg. 2:2:55-63) 18.f. for effecting relative movement between said lift frame and said plow blade; 18.g. said lift frame, plow blade and motion generating device being It may be stated that the hydraulic piston motors 86 illustrated in Figs. 17 and 18 are the same as those illustrated in other figures of the drawings, except for a small change in that the piston rods 90 are somewhat longer than the piston rods 90 (Id. at Pg. 5:2:19-24) It is thus manifest that the hydraulic piston motors 86 may be operated in the manner previously described in connection with Figs. 1 to 17 of the drawings, to adjust the auxiliary frame 140 about the axis of the pins 67 and thereby adjust the snow plow 146 upwardly and downwardly. (Ex. 1003, Pg. 5:2:32-38) To provide for the pivotal adjustment of the auxiliary frame 63 with respect to the main frame 33 about the axis of the pivot pins 67 which is a substantially horizontal axis, with the consequent raising and lowering of the snow plow 64 or blade 65 (Id. at Pg. 2:2:55-60) To provide for the attaching of a snow plow or other scraper blade to the 23

28 757 Patent Claims 6 and 18 Keeler (Ex. 1003) adapted to be attached to and detached tractor 20 so as to operate ahead from a vehicle as a single assembly. thereof, I provide a main frame 33 (Ex. 1003, Pg. 1:2:43-46) Claim 6.a. A snowplow assembly See supra Claim 18.a. comprising: 6.b. a lift frame; 6.c. a trunnion connected to said lift frame 6.d. an A-frame 6.e. having a plow blade on a forward end and 6.f. being connected on a rearward end to said trunnion; and See supra Claim 18.b. See supra Claim 18.b. pivotally attached to said angles 56 by pivot pins 67,67 (Keeler, Ex. 1003, Pg. 2:1:49-50) [A]uxiliary frame 140 comprises a rear part 141 formed by a pair of longitudinally extending downwardly sloping angle members 142 connected together by a transversely extending cross-angle143. (Ex. 1003, Pg. 4:2:4-8) See supra Claim 18.c. The rear ends of the angle members 142 are pivotally attached to the main frame 33 by the previously described means including the pivot pins 67 similar to the manner in with the castings 65 were attached thereto (Ex. 1003, Pg. 4:2:8-12) 6.g. a motion generating device 6.h. for effecting relative movement between said A-frame and lift frame; Each of said castings 65 is formed with a main shank 66 which is pivotally attached to the lower portion of the aforementioned angle members 56 by a pivot pin 67 (Id. at Pg. 2:1-2:74-3) See supra Claim 18.e. See supra Claim 18.f. 24

29 757 Patent Claims 6 and 18 Keeler (Ex. 1003) 6.i. said lift frame, trunnion, A-frame See supra Claim 18.g. and motion generating device all being attachable to and detachable from a vehicle as one assembly; 6.j. said lift frame, trunnion, A-frame See supra Claim 18.f. and plow blade being pivotally connected in such a manner that said plow blade can pivot relative to said lift frame about a transverse, horizontal axis 6.k. as well as can pivot relative to said See supra Claim 18.d. lift frame about a longitudinal, horizontal axis. Claims 1, 4-7, and 18 are Obvious Over Pruss and Kost or Watson Under 35 U.S.C. 103(a) As explained above, Pruss discloses, and therefore anticipates, every claim element of claims 1, 4-7 and 18 of the 757 patent. In the event, however, that it is determined: (1) that Pruss does not disclose the claimed A-frame (because, for example, the Pruss frame is arguably not shaped precisely like the letter A; 20 note, however, that DDI explicitly disclaims this limited interpretation; 21 and/or, (2) that Pruss does not disclose the claimed capability of one assembly or single assembly attachment and detachment (because, for example, the Pruss 20 Ex. 1001, 4:62-64; the 757 patent states, The A-frame 50 comprises a back bar 70 and a pair of side bars 72 arranged in a triangular or A configuration. 21 Id. at 8:36-40; the 757 patent states, (W)hile the term A-frame has been used herein, it is to be understood that other configurations of frames other than A's may be substituted therefore in the practice of the present invention and yet still be within the scope thereof. 25

30 vehicle is arguably not driven onto 22 the Pruss snowplow assembly), this section addresses alternative arguments that invalidate claims 1, 4-7 and 18 of the 757 patent as being obvious over Pruss in combination with US Patent No. 6,354,024 to Kost ( Kost ) or in combination with US Patent No. 5,125,174 to Watson ( Watson ). 1. Claims 1, 4-7 and 18 of the 757 patent are obvious over Pruss in view of US Patent No. 6,354,024 to Kost Kost is of record in the 757 patent and was used by the Examiner as a 102 anticipatory reference. To overcome this rejection, DDI argued that Kost did not disclose the claimed trunnion and that Kost did not disclose the claimed pivotal motion about a longitudinal, horizontal axis. 23 It appears that these two differences are the only differences between Kost and claims 1, 4-7 and 18 of the 757 patent. To assist in understanding Kost s components and operation, Figs. 13 and 20 from Kost are reproduced in Ex with identifying arrows added. Fig. 13 is a side view of a snowplow assembly attached to a vehicle. Fig. 20 is a perspective view of the A-frame with some components removed. Kost discloses a snowplow assembly including a lift frame 900 and an A- frame 750. To one end of the A-frame 750, shown in Fig. 13, is attached snowplow 22 Id. at 7:4-5; the 757 patent states, Vehicle 14 is driven onto snowplow assembly As discussed supra at Section V(B). 26

31 blade 710. The opposite end of the A-frame 750 is attached with a pair of pivot pins 652 (one on each side of the A-frame) received in holes 756 that define a transverse, horizontal pivot axis H-H, shown in Fig. 20, about which the A-frame 750 and snowplow blade 710 pivot when raised by activation of lift cylinder 950. Regarding driven onto attachment and detachment of the snowplow assembly, note the vehicle 450 shown on the right side of Fig. 13 has a mount housing 500 pre-attached. Note also that on the left hand side of Fig. 13 is the snowplow assembly including all the components discussed above. The snowplow assembly also includes a supporting assembly 600 having positioning flange 680 and guide lip 682. As the vehicle 450 is driven up to the snowplow assembly, portions of the mount housing 500 engage with the positioning flange 680 and guide lip 682 to connect the snowplow assembly to the mount housing 500 and thus to the vehicle 450. The connected condition is shown, for example, in Fig. 4. Thus, Kost discloses a driven onto attachment and detachment of the snowplow assembly. It would have been obvious to a person of skill in the art at the time to modify Pruss (Pruss 1 or Pruss 2) to use the driven onto attachment and detachment provided in Kost to simplify attachment and detachment of the snowplow assembly to the vehicle. The declaration of David Scott Smith further supports this conclusion. 24 This greater simplicity would reduce the time necessary for attachment 24 Ex at

32 and detachment, making the operators of the snowplow assembly more efficient saving time and money. The declaration of David Scott Smith further supports this conclusion as well. 25 Note that Pruss specifically mentions the advantages of simplifying attachment and detachment. 26 Regarding an A-frame shaped precisely like the letter A, note that Kost s A-frame 750, shown in Fig. 13 in Ex. 1014, is precisely in the shape of an A. It is also informative to compare the A-frame disclosed in the 757 patent with the A- frame 750 disclosed in Kost. Just below is the 757 patent A-frame on the left (a portion of Fig. 3A showing the A-frame) and on the right is the Kost A-frame (a portion of Fig. 20, rotated, showing the A-frame). It would have been obvious to a person of skill in the art at the time to modify 25 Id. 26 Ex. 1002, Pg. 4:1:35. 28

33 Pruss (Pruss 1 or Pruss 2) to use an A-frame shaped precisely like the letter A as provided in Kost as a matter of design choice and further to centralize, and therefore simplify, the attachment of the struts (26, 26 or 65, 65 ) to the plow blade 31. The declaration of David Scott Smith further supports this conclusion as well Claims 1, 4-7 and 18 of the 757 patent are obvious over Pruss in view of 5,125,174 to Watson Watson is of record in the 757 patent and was used by the Examiner as a 102 anticipatory reference. To overcome this rejection, DDI argued that Watson did not disclose the claimed trunnion and that Watson did not disclose the claimed pivotal motion about a longitudinal, horizontal axis. 28 It appears that these two differences are the only differences between Watson and claims 1, 4-7 and 18 of the 757 patent. To assist in understanding Watson s components and operation, Figs. 1 and 11 from Watson are reproduced in Ex with identifying arrows added. Fig. 1 is a side view of a snowplow assembly attached to a vehicle. Fig. 11 is a top view of the A-frame with some components removed and the dashed lines added. Watson discloses, with reference to Fig. 1, a snowplow assembly 18 including a lift frame 24 and an A-frame 22. To one end of the A-frame 22 is attached snowplow blade 20. The opposite end of the A-frame 22, as shown in Fig. 11, is 27 Ex at As discussed supra at Section V(B). 29

34 attached with a pair of pivot pins 80 (one on each side of the A-frame) received in holes that define a transverse, horizontal pivot axis 46 about which the A-frame 22 and snowplow blade 22 pivot when raised by activation of actuator means 110. Regarding driven onto attachment and detachment of the snowplow assembly 18, note the vehicle shown on the right side of Fig. 1 having a mount frame 16 pre-attached. Note that on the left hand side of Fig. 1 is the snowplow assembly 18 including all the components discussed above. The snowplow assembly 18 includes mounting plates 76 and the mount frame 16 includes mounting lugs 42. The snowplow assembly 18 and lift frame assembly 24 can be attached as a unit to the vehicle by the following steps: first, the vehicle can be moved into close proximity to the rearward ends 74 of the A-frame 22 so that the A-frame mounting lugs 42 and the A-frame mounting plates 76 are registered. 29 The attached condition is shown, for example, in Fig. 2. Thus, Watson discloses a driven onto attachment and detachment of the snowplow assembly. It would have been obvious to a person of skill in the art at the time to modify Pruss (Pruss 1 or Pruss 2) to use the driven onto attachment and detachment provided in Watson to simplify attachment and detachment of the snowplow assembly to the vehicle. The declaration of David Scott Smith further supports this 29 Ex. 1006, 9:62-68, (emphasis added). 30

35 conclusion. 30 This greater simplicity would reduce the time necessary for attachment and detachment, making the operators of the snowplow assembly more efficient saving time and money. The declaration of David Scott Smith further supports this conclusion as well. 31 Note that Pruss specifically mentions the advantages of simplifying attachment and detachment. 32 Regarding an A-frame shaped precisely like the letter A, note that Watson s A-frame 22, shown in Fig. 11 with dashed lines indicating the rest of the A-frame not shown, reproduced in Ex. 1013, is precisely in the shape of an A. It is, in fact, precisely like the A-frame disclosed in the 757 patent shown above. It would have been obvious to a person of skill in the art at the time to modify Pruss (Pruss 1 or Pruss 2) to use an A-frame shaped precisely like the letter A as provided in Watson as a matter of design choice and further to centralize, and therefore simplify, the attachment of the struts (26, 26 or 65, 65 ) to the plow blade 31. The declaration of David Scott Smith further supports this conclusion as well. 33 The following claim chart demonstrates on an element-by-element basis how the combination of Pruss with Kost or Watson renders the subject matter of challenged claims 1, 4-7, and 18 of the 757 patent obvious: 30 Ex at Id. 32 Ex. 1002, Pg. 4:1: Ex at

36 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) and Kost (Ex. 1004) or Watson (Ex. 1006) Claim 1.a. A snowplow assembly Pruss 1 and 2: This invention relates comprising: to plows which are attached to and driven by a vehicle, especially to road plows, such as snow plows (Pruss, Ex. 1002, Pg. 1:1;1-5) This invention is particularly applicable to a snowplow apparatus (Kost, Ex. 1004; 1:19-20) 1.b. a lift frame; This invention relates generally to snowplow blade lift assemblies (Watson, Ex. 1006, 1:7-8) Pruss 1 and 2: A rigid tower 20 is mounted on the abutment plates 13-13, braced by tie rods 21-21, and provided with resilient supporting means and hoisting means (Pruss, Ex. 1002, Pg. 2:2:71-74) The frame mount assembly 400 is made up of four principal components, namely and a lift mount assembly 900 which is also secured to the support assembly. (Kost Ex. 1004, 19:34-42) Lift mount assembly 900 includes a pair of lift legs 910 laterally spaced from one another. A support bar 920 is secured between the two lift legs which in turn secures the lift legs to the inner leg and outer leg 610, 612 of the support assembly 600. (Id. at 23:27-31) 32

37 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) and Kost (Ex. 1004) or Watson (Ex. 1006) A lift frame assembly 24 is pivotally connected to the A-frame 22 (Watson, Ex. 1006, 4:56-58) 1.c. a trunnion 1.d. pivotally connected to said lift frame for pivoting movement about a transverse, horizontal axis; 1.e. an A-frame Pruss 1: a circular transverse bolster 55 rotatably mounted in slides (Id. at Pg. 4:2:25-27) Pruss 2: a tiltable bolster 18, located between the bars 14, and extending through notches 13a, cut in the plates (see Figures 6 and 7). (Pruss, Ex. 1002, Pg. 2:2:52-58) Pruss 1: bolster 55 rotatably mounted in slides 56-56' (Pruss, Ex. 1002, Pg. 4:2:26-27) Pruss 1: The bolster 55 may be retained by means of a pin or trunnion bolt 59 extending between the bars and through an elongated hole 60 in the bolster 55, the hole being shaped to permit the bolster to rotate about its axis through an arc of about 30 degrees or less. (Id. at Pg. 4:2:34-39) Pruss 1: Struts 65-65' (corresponding to the struts 26-26' shown in Figures 1 to 7) are fixedly secured to the slides 63, and form the sides of the plow frame. (Id. at Pg. 4:2:64-67) 33 Pruss 2: Fixedly secured to the bars 25 (one on each end of the bolster 18) is a pair of forwardly extending struts forming the side members of the plow supporting frame. (Pruss, Ex. 1002, Pg. 3:1:11-14)

38 757 Patent Claims 1, 4-7, and 18 Pruss (Ex. 1002) and Kost (Ex. 1004) or Watson (Ex. 1006) Pruss 1 and 2: The struts may be suitably reinforced against buckling, and provided with a transverse bar 30. (Id. at Pg. 3:1:24-26) Secured or attached to structural frame 712 is A-frame 750. A-frame structure is best shown in FIG. 20. (Kost, Ex. 1004, 19:50-52) A snowplow assembly 18 including a snowplow blade 20 is connectable to the mounting frame assembly 16 through an A-frame 22 which extends forwardly from the vehicle. (Watson, Ex. 1006, 4:53-56) 1.f. having a plow blade on a forward end and (Declaration of David Scott Smith Ex. 1019, at 29-30) Pruss 1 and 2: The forward ends of the struts are curved to fit the rear surface of a plow blade 31, to which they may be fixedly secured (Pruss, Ex. 1002, Pg. 3:1:26-28) [B]lade mount assembly 700 includes a plow blade (Kost, Ex. 1004, 19:43-44) The A-frame also includes two struts 760 which are connected at one end to the cross over arm and at the other end to a mount plate 770. (Id. at 19:56-58) As shown in FIGS , an arcuate connector bar 720 is used to 34