Black & Decker US Inc v. Christy Inc

1. Case Identification

• Case #: IPR2015-00472
• Patent #: 7,082,640
• Petitioner(s): Black & Decker (U.S.) Inc. and Stanley Black & Decker, Inc.
• Patent Owner(s): Christy, Inc.
• Challenged Claims: 1, 4-10, and 13-18

2. Patent Overview

• Title: Ambient Air Backflushed Filter Vacuum
• Brief Description: The ’640 patent discloses a vacuum cleaning machine with multiple filters that are sequentially cleaned using a backflush of ambient air. The system uses the main vacuum source's negative pressure to draw outside air in reverse through one filter at a time, avoiding the need for a separate compressed or forced air source.

3. Grounds for Unpatentability

Ground 1: Anticipation by Eiben - Claims 1 and 10 are anticipated by Eiben.

• Prior Art Relied Upon: Eiben (Patent 3,224,172).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Eiben disclosed every element of independent claims 1 and 10. Eiben taught a dust collector with multiple filter compartments forming a "cannister," a blower acting as a "vacuum source," and external valves for each compartment. Petitioner asserted that Eiben’s valves switch individual filters from the vacuum source to an ambient air inlet, which allows the system's ongoing suction to draw ambient air backward through the selected filter for cleaning. This process matches the claimed backflushing mechanism.
  • Key Aspects: The "means for sequentially operating said valves" was met by Eiben's express disclosure of using either motors or an "electric solenoid" to operate its valves. Petitioner contended the solenoid is the identical structure disclosed in the ’640 patent for performing the same function.

Ground 2: Obviousness over Eiben and Wellan - Claims 1, 4-6, 10, and 13-15 are obvious over Eiben in view of Wellan.

• Prior Art Relied Upon: Eiben (Patent 3,224,172) and Wellan (Patent 3,680,285).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative to anticipation. Eiben was asserted to provide the base vacuum system with solenoid-actuated valves. Wellan was argued to supply the specific electronic controller features for timing the backflush sequence, including the "means for setting a cycle time" (claims 4, 6, 13, 15) and "means for setting said intermittent time" (claims 5, 6, 14, 15). Wellan’s controller used a solid-state timer to trigger solenoids and allowed user adjustment of the pulse duration ("Pulse On-Time") and sequence rate.
  • Motivation to Combine: A POSITA would combine these references because Eiben taught a system using solenoids but lacked an express disclosure of a specific controller for governing their timing. Wellan provided a conventional electronic controller for the exact purpose of timing backflush solenoids in a filter system. Petitioner argued that using Wellan's known controller to time the solenoids in Eiben's system was a predictable combination of known elements for their established functions.
  • Expectation of Success: The combination involved applying a standard electronic controller to a known mechanical system, which would have presented no technical hurdles and provided a high expectation of success.

Ground 3: Obviousness over Eiben, DE219, and Howeth - Claims 7-9 and 16-18 are obvious over Eiben, DE219, and Howeth.

• Prior Art Relied Upon: Eiben (Patent 3,224,172), DE219 (DE Publication # 10101219), and Howeth (Patent 4,465,497).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground targeted dependent claims reciting a valve with a "piston" and a "means biasing said piston." Eiben provided the base system using a flap-style valve. DE219 taught a reciprocating piston valve controlled by electromagnets and described it as an interchangeable and "obvious[]" alternative to other valve types, including flap valves. Howeth taught using a spring to bias a valve actuator in a nearly identical ambient air backflush system, demonstrating a common method for ensuring a valve returns to its normal position.
  • Motivation to Combine: A POSITA would have been motivated to substitute Eiben's flap valve with the known reciprocating piston valve from DE219 as a simple design choice between interchangeable parts. Further, a POSITA would find it obvious to add a biasing spring, as taught by Howeth, to the piston valve from DE219. This addition was argued to be a simple, well-known mechanical improvement to ensure the piston reliably returned to its default position.
• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations including Rolchau (Patent 3,963,467), but relied on similar arguments for providing motivation to use an electronic controller in an ambient air backflush system.

4. Key Claim Construction Positions

Petitioner argued that several claim terms required specific constructions based on the patent's specification and prosecution history, which consistently distinguished the invention from prior art using forced or compressed air.

• "ambient air": Proposed construction was "air from the area surrounding the outside of the vacuum cleaning machine that has not been forced or compressed." This was based on the patent’s explicit denigration of forced/compressed air systems for backflushing.
• "drawn": Proposed construction was "pulled in by negative pressure only." This construction was argued to be coextensive with "ambient air" and was supported by prosecution history statements emphasizing that the invention uses the system's own vacuum suction, not positive pressure, to create the backflush.
• "means for sequentially operating": Petitioner argued this was a means-plus-function term under 35 U.S.C. §112(f) corresponding to the disclosed solenoids that directly actuate the valves. It was argued not to include the separate electronic controller, which corresponded to other, separately claimed functions like setting the intermittent and cycle times.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1, 4-10, and 13-18 of Patent 7,082,640 as unpatentable.