Brunswick Corp v. Volvo Penta Of Americas LLC

1. Case Identification

• Case #: IPR2020-01512
• Patent #: 9,630,692
• Filed: August 24, 2020
• Petitioner(s): Brunswick Corporation
• Patent Owner(s): AB Volvo Penta
• Challenged Claims: 1-18

2. Patent Overview

• Title: Steerable Tractor-Type Drive for a Boat
• Brief Description: The ’692 patent discloses a marine drive system for a boat, specifically a "tractor-type" or "pulling-propeller" drive. The invention focuses on the geometric relationship between the drive's steering axis, vertical drive shaft, and propellers to minimize steering torque and improve performance.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-3, 11-13, 15, and 17-18 under 35 U.S.C. §102

• Prior Art Relied Upon: Kiekhaefer (Patent 2,616,387).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kiekhaefer, which describes a reversible lower end unit for outboard motors, discloses every element of the challenged independent and dependent claims. Petitioner asserted Kiekhaefer teaches a steerable, tractor-type drive for a boat with a drive support mountable to the stern (clamp and swivel brackets). It was argued that Kiekhaefer’s drive housing pivots about a vertical steering axis, is driven by a vertical drive shaft connected to a propeller shaft, and uses a forward-mounted "tractor-type" pulling propeller. Critically, Petitioner contended that Kiekhaefer’s drawings show the steering axis is offset forward of the vertical drive shaft, meeting a key limitation of claim 1. For claims requiring the center of pressure to be rearward of the steering axis, Petitioner argued this is an inherent property of Kiekhaefer’s design because its underwater housing is located rearward of the steering axis.

Ground 2: Obviousness of Claims 4 and 7 under 35 U.S.C. §103

• Prior Art Relied Upon: Kiekhaefer (Patent 2,616,387) and Stechauner (Patent 1,813,552).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Kiekhaefer provides the base steerable tractor-drive system as detailed in Ground 1. Stechauner was introduced to supply the teaching of using two counter-rotating pulling propellers (for claim 4) and a pair of coaxial, counter-rotating pulling propellers (for claim 7), which Kiekhaefer’s single-propeller embodiment lacks. Stechauner explicitly teaches the use of "two oppositely revolving propellers" to increase tractive effort.
  • Motivation to Combine: A POSITA would combine these references to gain the known advantages taught by Stechauner—namely, obtaining "almost one-third more tractive effort" over a single propeller with only a minimal increase in energy expenditure. Petitioner argued it would have been a simple substitution of one known element (Kiekhaefer's single propeller) for another (Stechauner's dual propellers) to achieve a predictable improvement in performance.
  • Expectation of Success: The combination was asserted to be straightforward, as both references relate to outboard marine drives and address improving propulsive force, leading to a high expectation of success.

Ground 3: Obviousness of Claims 1-18 under 35 U.S.C. §103

• Prior Art Relied Upon: Brandt (Patent 4,840,136) and Kiekhaefer (Patent 2,616,387).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Brandt discloses a modern inboard-outboard marine drive with key features like a drive housing pivotable about a steering axis and dual counter-rotating propellers, but in a "pusher-type" configuration. Kiekhaefer was argued to supply the missing teaching of a "tractor-type" or "pulling-type" configuration. Petitioner asserted that Kiekhaefer explicitly teaches the benefits of a tractor-type propeller, stating it is "more efficient and capable of higher speeds," and provides instructions for reversing a lower drive unit to convert it from a pusher to a tractor configuration. The combination of Brandt's drive with Kiekhaefer's tractor-propeller teaching was alleged to render all claims obvious.
  • Motivation to Combine: A POSITA would have been motivated to modify Brandt’s pusher-type drive using Kiekhaefer’s teachings to achieve the known benefits of a tractor-type system, such as improved efficiency and higher speeds. This was presented as an obvious substitution of one known propeller type for another to obtain predictable results. The desire for faster, more efficient boats provided a strong commercial motivation for this combination.
  • Expectation of Success: Petitioner argued there was a reasonable expectation of success because Kiekhaefer teaches how to create a reversible lower unit, making the modification to Brandt's drive a predictable design choice for a POSITA.

• Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 4 and 7 based on the combination of Brandt, Kiekhaefer, and Stechauner, relying on similar theories where Stechauner provides an explicit teaching for dual counter-rotating pulling propellers to be used in the modified Brandt drive.

4. Key Claim Construction Positions

• "a center of pressure applied by water moving past the drive housing during a turn" (claims 8, 11, 17, and 18):
  • Petitioner argued this term should be construed to mean "the point where the net force of the water flow acts on the underwater portion." This construction was based on the patent's own definition in the specification, which states the "center of pressure is the point where the total sum of a pressure field may be considered to act on a body." Petitioner further argued the patent admits that if the underwater housing is mostly rearward of the steering axis, the center of pressure will necessarily be rearward of the steering axis, making this an inherent feature in prior art with such a configuration.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-18 of the ’692 patent as unpatentable.