Court: Court of Appeals for the Federal Circuit; July 7, 2004; Federal Appellate Court
James F. McNulty, Jr. appeals the summary judgment order from the United States District Court for the Central District of California, which ruled in favor of Taser International Inc. regarding noninfringement of United States Patent No. 5,193,048 (the '048 patent). McNulty is the exclusive licensee of the '048 patent, which relates to a stun gun featuring a low battery indicator and shutoff timer. The patent is assigned to Richard Bass, whose company produces products that utilize the patented technology. Although McNulty has sublicensed the patent, he retains the right to pursue infringement claims.
McNulty alleged that Taser's products—the U34000, M18-L, and M26—violated claim 39 of the '048 patent. Claim 39 outlines an electrical shock device with specific components, including a housing, a power supply, an electronic circuit, and a trigger mechanism. During the Markman hearing, the district court focused on the second and third limitations of claim 39. It defined these limitations as means-plus-function limitations under 35 U.S.C. § 112, paragraph 6, requiring the identification of corresponding structures within the patent specification.
The district court highlighted a circuit schematic from Figure 5 of the '048 patent as depicting key structural components. It identified SW1, the trigger, as a mechanical switch, although the exact type was unclear. The court established that the trigger must be located on the housing, defined as the part containing the internal electrical components. It clarified that the "first position" refers to the closed position that connects the circuit and that "selectively connecting" means the user has control over when the circuit is opened or closed, not limited to the initial connection. The court consistently referenced SW1 in its claim construction analysis.
The district court determined that the trigger means for the stun gun could only be a mechanical switch, rejecting McNulty’s argument that it could be an electronic switch operating via a mechanical one. The court identified three reasons for this conclusion: (1) the flip-flop switch was not located "on the housing" as required by claim 39; (2) the power supply connection did not depend on the trigger means being in a "first position," but rather on an internal electronic switch; and (3) the internal switch failed to "selectively connect" the power supply, as releasing the trigger did not disconnect the circuit. The court clarified that the trigger means must be a mechanical switch directly operated by the user to connect or disconnect the power supply and oscillator. It stated that this mechanical switch could be a momentary or hard-on switch.
The court also analyzed the "means for disabling the electronic circuit" when the trigger means is continuously operated in the first position. It identified an integrated circuit chip timer as this disabling means, which would only activate when the trigger was held in the "on" position for a predetermined time.
When addressing infringement claims regarding Taser’s U34000 device, the court noted that activation required closing both a safety switch and a trigger switch. The safety switch connected the power supply, while the trigger discharged the device. McNulty's first infringement theory was dismissed because neither switch operated simultaneously in the required "first position." The second theory, which included additional internal switches, was also rejected as these switches were not located "on the housing." Thus, the court concluded that the U34000 did not satisfy the requirements of claim 39.
The district court did not explicitly identify the 'trigger means' in Taser's devices but determined that the U34000 does not infringe claim 39 of the relevant patent. It found that the claim's limitation regarding the disabling means was not met, as the U34000's disabling mechanism did not rely on the 'trigger means' being in a specific position. Once the U34000's discharge sequence started, changes to the position of the 'trigger means' were inconsequential. Additionally, the absence of equivalents to the disabling means limitation further justified the conclusion of noninfringement, both literally and under the doctrine of equivalents. The court noted that Taser’s M-26 and M-18L devices operated similarly to the U34000, requiring a safety switch to be closed and a trigger pressed to function for a set period. The court's analysis for these devices mirrored that for the U34000, leading to a consistent outcome. Consequently, the district court granted summary judgment for noninfringement. McNulty appealed, and the court has jurisdiction under 28 U.S.C. 1295(a)(1).
The review of summary judgment is de novo, emphasizing that such judgment is appropriate when no material factual issues exist—meaning no reasonable jury could find that all limitations of the claim are present in the accused device. Infringement involves two steps: first, the construction of the claims' meaning and scope, which is a legal question, and second, a comparison of those claims to the accused device. McNulty contends that the district court wrongly required the current to flow through the trigger means and misinterpreted 'selectively connecting.'
The Taser devices operate through a predetermined electrical discharge sequence that cannot be interrupted by the operator once the trigger is released; however, the operator can control the repetition of this sequence by continuing to hold the trigger. McNulty characterizes this as a form of selective disconnection. In determining means-plus-function limitations, a court must first identify the claimed function and then the corresponding structure in the patent specification. In this case, the district court identified SW1 in FIG. 5 of the ’048 patent as the corresponding structure for the 'trigger means' in claim 39, a determination not contested by McNulty. The function of the trigger is to connect the power supply to the electronic circuit when in the specified first position, which is agreed to be when SW1 is closed. The term 'selectively' indicates the operator's choice to activate the device. The patent's description supports this interpretation, confirming that switch SW1 connects the power source to the circuit when closed. The court affirmed that 'selectively connecting' entails the connection occurring only when the trigger is in the first position, allowing the operator to control the connection. The court also noted that for infringement under section 112, paragraph 6, a structure may be considered an equivalent under the doctrine of equivalents if it performs substantially the same function in a similar way, even if not identical. The Taser’s sequence continues to operate automatically once activated, independent of the trigger’s position.
The operator's control over the Taser trigger does not affect the discharge sequence, which continues until completion regardless of whether the trigger is held or released. McNulty concedes this point, and as such, the Taser devices do not fulfill the "trigger means" function outlined in claim 39 since the power supply and electronic circuit are not selectively connected by a trigger in a first position. The district court's summary judgment of no literal infringement is upheld, along with the judgment of no infringement under the doctrine of equivalents. The court emphasized that applying the doctrine too broadly would effectively nullify the specific functional requirements of the "trigger means." While McNulty argues that the operator’s ability to repeatedly press the trigger qualifies as "selective connection," Taser contends that the discharge sequence can only repeat upon releasing and re-pulling the trigger, a point the district court clarified during the summary judgment hearing. The district court found that once the discharge sequence is initiated, the trigger's position becomes irrelevant, and concluding otherwise would undermine the claim's requirements. Ultimately, accepting all of McNulty's evidence as true, the court affirmed that Taser's U34000 and M-series products do not infringe the 'trigger means' limitation of claim 39, with no costs awarded. The district court also provided details on the preset sequence of the U34000 device and recognized the 'electronic circuit' in claim 39 as a "classic relaxation oscillator" as described in the patent.
The district court's construction of the 'triggering means' in Taser devices is supported, emphasizing that the physical trigger operated by the user must be included within this definition. McNulty's argument that the triggering means could consist of multiple components is countered by the requirement that the trigger must be in the first position while the power supply and electrical circuit are engaged. The court's inquiry revealed that when the trigger is compressed, the device operates for a fixed five seconds, regardless of whether the trigger remains depressed, necessitating a release and reactivation for subsequent use. This exchange clarifies the operational limitations and requirements of the device's triggering mechanism.
