United States Patent 7,246,615: Scope, Claim Coverage, and US Landscape
US Patent 7,246,615 is directed to a spray generating device that combines (1) a metered, spring-driven piston discharge architecture with (2) a multi-outlet impinging-jet nozzle assembly built from mated members that form passageways terminating in discrete nozzle outlets. The key commercial value of the patent is the coupling of a rapid pressure rise over a metered dose (from near-ambient hold) with a structured micro-nozzle plate design that creates atomization through jet impingement.
What does claim 1 actually require?
Core system elements (claim 1)
Claim 1 requires all of the following, in combination:
- Reservoir holding a medicament.
- Pump with piston, spring, and cylinder, where:
- the piston has a retracted position and a deployed position
- movement to the retracted position draws a metered dose from the reservoir into a pressure chamber
- the medicament sits in the pressure chamber at ambient pressure until discharge
- when discharge is required, the piston moves from retracted to deployed and the spring drives the piston forward to generate a rapid pressure rise that discharges the metered dose.
- Nozzle assembly that atomizes the discharged fluid into inhalation-suitable droplets.
- Nozzle assembly construction:
- First member with a first surface having a plurality of grooves.
- Second member with a second surface such that the two surfaces are joined to form a plurality of passageways.
- Nozzle outlets at one end of the passageways.
- The nozzle outlets discharge a plurality of fluid jets such that the jets impinge on one another to atomize.
Functional linking
Claim 1 ties the pumping event to nozzle performance via a single discharge path:
- metered dose is held at ambient pressure in a chamber
- then piston spring action produces a rapid pressure rise
- discharge goes to the micro/nozzle outlet manifold
- impinging jets create atomization suitable for inhalation.
That coupling matters because the claim is not just about micro-nozzles; it is about the full device architecture.
How broad is the claim set?
Claim 1 provides a broad architectural frame but includes several technical limits that narrow coverage in practice:
Broadest coverage within claim 1
Coverage is relatively broad on:
- Medicament type (no formulation limitation in provided claims)
- Use context beyond droplets “suitable for inhalation” (not limited to specific actives)
Narrowing limits in claim 1
Coverage narrows on:
- the metering and ambient-pressure hold in the pressure chamber
- the rapid pressure rise from a spring-driven piston stroke
- the specific nozzle manufacturing concept (grooves + mated member surfaces to form passageways)
- impinging-jet atomization using multiple outlets where jets impinge.
Claim-by-claim scope analysis (1–20)
Claim 1: What is the essential invention combination?
Spray generating device with:
- spring-driven piston pump that draws a metered dose into a pressure chamber,
- holds at ambient pressure,
- then a rapid spring-driven pressure rise discharges the metered dose, and
- a microstructured impinging-jet nozzle assembly made from two members with grooves and mated surfaces forming passageways ending at multiple outlets producing impinging jets.
Practical infringement gate: A product must replicate the combination of:
- the “metered dose at ambient hold + rapid pressure rise discharge” pumping logic, and
- the “mated-groove micro/nozzle passageways + multiple outlets producing impinging jets” nozzle logic.
Claim 2: What does adding a filter change?
Claim 2 adds: a filter disposed at one end of the plurality of passageways.
Scope effect:
- Narrows to devices with an upstream or inline filter at that junction.
- Infringement requires the filter placement as claimed.
Claim 3: What does passageway geometry limit?
Claim 3 requires passageways with substantially rectangular cross-section.
Scope effect:
- Narrows to nozzle plate architectures whose internal channels are rectangular rather than circular/triangular/elliptical.
Claims 4–6: What do jet impingement angles cover?
- Claim 4: impingement at ~60° to ~150°.
- Claim 5: impingement at ~90° to ~120°.
- Claim 6: impingement at ~90°.
Scope effect:
- These are nested ranges. Any jet impingement angle falling inside any dependent claim range could meet those narrower claims, but all dependents sit under claim 1’s base structure.
- Products with impingement not within these angle windows may avoid these dependent claim layers, but could still potentially meet claim 1 if angles were not required by claim 1 (claim 1, as provided, does not specify an angle range).
Claim 7: What does adding a plenum chamber require?
Claim 7 adds: a plenum chamber formed in the first member, in fluid communication with the passageways.
Scope effect:
- Requires internal distribution volume within the first member feeding the passageways.
- If a design uses a different distribution manifold outside the first member or on the second member only, claim 7 may be missed.
Claim 8: What does parallel passageways constrain?
Claim 8 limits: passageways are substantially parallel.
Scope effect:
- Excludes designs where channels diverge/converge or are radially arranged.
Claim 9–11: What do inlet architecture limitations add?
- Claim 9: nozzle assembly further comprises a fluid inlet.
- Claim 10: inlet disposed substantially at a right angle to the first member.
- Claim 11: adds a fluid inlet chamber receiving medicament from the inlet and in fluid communication with the passageways.
Scope effect:
- These dependents constrain mechanical integration and flow path orientation.
- Many real devices could have an inlet but not at the “right angle” orientation or without the specific chamber arrangement.
Claims 12–14: What do pressure and pressure-drop limits define?
- Claim 12: passageways configured for medicament flow supplied at at least 50 bar.
- Claim 13: ~50 to ~400 bar.
- Claim 14: passageways impose a pressure drop of ~0.2 to ~25 bar.
Scope effect:
- These are high-leverage dependent limitations.
- If a device’s operating regime falls below 50 bar, or outside the 50 to 400 bar supply window, the dependent claims 12–13 may not cover it.
- If the pressure drop across the nozzle passageways falls outside the 0.2 to 25 bar window, claim 14 may not cover.
In practice: even if pumping can create rapid pressure rise, the actual flow conditions at the nozzle passageways determine these dependents.
Claims 15–16: What do outlet area limits control?
- Claim 15: total cross-sectional area of nozzle outlets ~25 to ~500 µm².
- Claim 16: total cross-sectional area ~30 to ~200 µm².
Scope effect:
- Constrains microfabricated outlet total area.
- Many nozzle plate designs could miss these windows if they use different outlet dimensions, number of outlets, or inlet-to-outlet sizing.
Claims 17–20: What do material pairings specify?
- Claim 17: first member comprises silicon.
- Claim 18: first member further comprises glass.
- Claim 19: second member comprises silicon.
- Claim 20: second member further comprises glass.
Scope effect:
- These are strong manufacturing qualifiers.
- Many impinging-jet devices use stainless, nickel alloys, polymers, or silicon-glass hybrids only for one plate surface. Missing silicon or glass inclusion can avoid these dependents even if the functional impingement and channel formation are the same.
US Patent 7,246,615 claim coverage map (device feature matrix)
| Feature |
Claim(s) |
Coverage impact |
| Spring-driven piston metering with ambient hold |
Claim 1 |
Central limitation; hard to design around while preserving performance |
| Rapid pressure rise at discharge |
Claim 1 |
Coupled with ambient hold; constrains actuator timing/pressure profile |
| Two-member nozzle with grooves + mated surfaces forming passageways |
Claim 1 |
Manufacturing-method-like limitation that is difficult to replicate without similar microfabrication |
| Multi-outlet impinging jets for atomization |
Claim 1 |
Must produce impingement atomization via multiple jets |
| Optional filter at passageway end |
Claim 2 |
Narrow add-on |
| Rectangular passage cross-section |
Claim 3 |
Geometric constraint |
| Jet impingement angle ranges |
Claims 4–6 |
Dependent on angle measurement/definition |
| Plenum in first member |
Claim 7 |
Restricts distribution structure |
| Substantially parallel passageways |
Claim 8 |
Channel layout constraint |
| Inlet and inlet chamber architecture |
Claims 9–11 |
Mechanical integration constraint |
| Flow pressure at least 50 bar; 50–400 bar window |
Claims 12–13 |
Operating regime constraint |
| Passage pressure-drop 0.2–25 bar |
Claim 14 |
Hydraulic constraint |
| Total nozzle outlet area windows (25–500 µm²; 30–200 µm²) |
Claims 15–16 |
Micro-scale sizing constraint |
| Silicon and glass material pairings |
Claims 17–20 |
Manufacturing/material constraint |
Design-around and freedom-to-operate signals (based on the claim structure)
Most likely infringement risk areas
- Pumping architecture match: ambient-pressure hold in a pressure chamber followed by spring-driven rapid pressure rise to discharge a metered dose.
- Nozzle architecture match: grooves in a first member, joined mated second surface forming passageways, ending in multiple outlets discharging jets that impinge.
- Operating regime match: nozzle passageway pressure-drop and total outlet area if those match the dependent claim windows.
Common ways to avoid dependent-layer claims (not necessarily claim 1)
- Use a different nozzle fabrication structure (no grooved first member + mated surface to form passageways).
- Replace impinging-jet atomization with a different mechanism (e.g., swirl/vortex, piezo droplet breakup) if it eliminates “jets impinge on one another” atomization.
- Operate below 50 bar or with different pressure-drop behavior.
- Use different channel cross-sections or non-parallel channel layouts.
- Employ different materials (avoid silicon/glass inclusion on one or both members).
Patent landscape: what similar systems typically include
US 7,246,615 sits in a niche at the intersection of:
- dose metering + rapid actuation for inhalation delivery
- microfabricated multi-orifice / impinging-jet atomization using mated channel plates.
In practice, competitive filings and later improvements in this area tend to cluster around three axes:
- Actuation and metering: capacitive/piezo vs solenoid vs spring/piston, and how the system stores and releases medicament energy.
- Atomization mechanics: impinging jets vs swirl/vortex vs membrane/piezo breakup.
- Micro-nozzle manufacture: silicon/glass wafer bonding vs metal EDM/manifolds vs molded polymer channels.
Because the provided claims include both a specific actuation architecture and a specific nozzle microfabrication concept, the patent’s protected space is best read as a combination claim. That combination posture limits straightforward workarounds that change only one axis.
Key Takeaways
- Claim 1 is the anchor: infringement requires both a spring-driven, metered piston discharge with ambient-pressure hold and a two-member grooved/mated micro-nozzle that forms passageways ending in multiple outlets producing impinging jets for inhalation-grade atomization.
- Dependent claims 2–20 layer on manufacturability and operating parameters: filter placement, rectangular channels, impingement angles, plenum integration, inlet geometry, pressure windows (>=50 bar; 50–400 bar), pressure-drop (0.2–25 bar), total outlet area (25–500 µm² or 30–200 µm²), and silicon/glass materials.
- The patent’s strongest practical protection is the coupled architecture. Designs that change the nozzle atomization mechanism or the piston/pressure-release logic face the largest claim-1 risk.
- For value planning, the high-leverage diligence items are the pressure profile and micro-nozzle channel/outlet geometry because they map directly to multiple dependent claim limitations.
FAQs
1) Does claim 1 require jet impingement at a specific angle?
No. Claim 1 requires that jets “impinge on one another,” but it does not impose an angle range. Angle limits appear only in dependent claims 4–6.
2) Can a device avoid dependent claims 15–16 by changing outlet dimensions?
Yes. Dependent claims 15–16 constrain the total cross-sectional area of all nozzle outlets. Changing the number of outlets, outlet width/height, or the total area can avoid those dependents if claim 1’s structural requirements are still not escaped.
3) Is the nozzle material (silicon/glass) required for infringement of claim 1?
No. Silicon and glass limitations appear only in claims 17–20. Claim 1 does not require a specific material.
4) Is the ambient-pressure hold requirement a critical discriminator?
Yes. Claim 1 requires the metered dose be held in the pressure chamber “at ambient pressure” until discharge, then discharged via a spring-driven rapid pressure rise.
5) Would operating the device at below 50 bar avoid claim coverage?
It can avoid dependent claim 12 and related pressure-window dependents (claims 12–14), but claim 1 does not, by itself, recite the 50–400 bar window in the provided text.
References
[1] United States Patent and Trademark Office. US 7,246,615.
