United States Patent 5,964,416: Claim Scope, Expiration, and Atomizer Patent Landscape

U.S. Patent No. 5,964,416 is a device patent directed to a spring-driven, high-pressure liquid atomizer associated with the Respimat-style soft-mist inhaler platform. Its claims cover three related technical configurations: a complete atomizing device, a reservoir-and-pump architecture, and a reciprocating piston pump with an anti-rotation valve.

The patent does not claim a pharmaceutical active ingredient. Its commercial relevance is therefore concentrated in inhaler and atomizer hardware, replaceable liquid reservoirs, pump mechanisms, valves, nozzle structures, and manufacturing configurations. The patent is expired and does not create a current U.S. blocking right against generic or competing products. Its historical claim scope remains relevant for understanding the patent lineage of soft-mist inhalers and later continuation, divisional, and improvement patents.

What does U.S. Patent 5,964,416 cover?

The patent covers a mechanically actuated atomizer that stores energy in a spring, releases that energy to drive a piston, pressurizes a measured liquid volume, and discharges the liquid through a fine atomizing nozzle.

The principal technical combination includes:

Technical element	Claimed function
Upper and lower housing parts	Enclose the atomizer mechanism and liquid container
Pump housing and cylinder	Define the pumping structure and pressure chamber
Hollow piston	Provides the liquid flow path and pressurizes the liquid
Axially movable valve member	Controls filling and discharge of the pressure chamber
Rotatable spring housing	Stores mechanical energy in a spring
Blocking mechanism	Retains the spring in a biased state
Actuating button or latch	Releases the stored spring energy
Fine nozzle	Converts pressurized liquid into an aerosol
Replaceable storage container	Supplies liquid to the pump
Counter	Records operation or dose use

Claim 1 is the broadest complete-device claim. It requires the combination of the housing, spring-driven pump, hollow piston, axially aligned valve member, pressure chamber, and nozzle. A product that omits one required limitation may avoid literal infringement of claim 1, although it could still implicate claims 14 or 20.

The patent is broader than a claim limited to a particular drug. It is directed to the mechanical architecture for atomizing fluid, including pharmaceutical liquids.

How are the independent claims divided?

The independent claims create three separate claim groups.

Claim 1: spring-driven atomizing device

Claim 1 requires:

A housing with upper and lower housing parts.
A pump housing in the upper housing part.
A cylinder and pressure chamber.
A hollow piston.
A valve member that moves axially with the piston.
A rotatable spring housing.
A spring held in a biased state by a blocking mechanism.
Spring release that closes the valve and pressurizes fluid.
A nozzle that atomizes the pressurized fluid.

The claim is a combination claim. It does not cover every atomizer or every spring-driven pump. The accused product would need to practice the specified relationship among the spring housing, valve member, hollow piston, cylinder, and nozzle.

The claim also contains functional language. The spring-release event must cause both valve closure and piston-driven pressurization. A device in which the valve is controlled independently, or in which pressure is generated by a different mechanism, may present a noninfringement position.

Claim 14: reservoir-and-pump architecture

Claim 14 is structurally different. It covers an atomizer having:

An atomizing nozzle;
A pump with a cylinder and tubular piston;
A piston that provides the inlet flow path;
A valve member movable with the piston;
A liquid reservoir;
A cap penetrated by the remote end of the piston;
A reservoir and piston fixed relative to each other during operation; and
Relative reciprocation between the piston and cylinder.

This claim focuses on how the pump interfaces with the liquid reservoir. The cap-penetration limitation is important. The piston is not merely positioned near a reservoir opening. The claim requires the cap to be penetrated by the second end of the piston so liquid can flow through the piston during the induction stroke.

That feature may limit the claim against atomizers using:

A separate dip tube;
A permanently open reservoir outlet;
A flexible tube between the reservoir and pump;
A conventional check-valve inlet;
A piston that does not penetrate the reservoir cap.

Claim 14 does not expressly require the rotatable spring housing recited in claim 1. It is therefore a potentially distinct infringement pathway for products using the claimed reservoir and piston arrangement but a different spring housing configuration.

Claim 20: reciprocating pump and anti-rotation valve

Claim 20 covers a reciprocating pump device with:

A cylinder;
A hollow cylindrical piston;
A piston passage for fluid;
A pressure chamber;
A valve seat formed by a portion of the piston; and
A valve member that moves with the piston between open and closed positions.

The distinctive limitation is that the valve member cannot rotate about an axis transverse to the piston axis.

This anti-rotation limitation is narrower than a generic valve limitation. It targets controlled axial valve movement and prevents the valve from tilting or rotating in a manner that could impair sealing or pump operation.

What do dependent claims 2 through 13 protect?

The dependent claims add specific mechanical and aerosol features.

Claim	Added limitation	Scope significance
2	Annular land, groove, and undercut snap hook	Covers a particular snap-retained valve-to-piston connection
3	Inwardly shaped piston edge and undercut peg	Covers a second valve-retention structure
4	Widened piston portion receiving the valve	Limits valve movement within an enlarged piston region
5	Inward edge and encircling constriction	Defines another piston-retention arrangement
6	Closure member with depression for the valve	Covers valve support through a closure member
7	Actuating button	Narrows operation to manual spring release
8	Spindle-and-slide counter	Adds a dose or actuation-counting mechanism
9	Two-plate nozzle and hydraulic diameter of 10 micrometers or less	Covers microchannel nozzle construction and very small outlet geometry
10	At least two inclined nozzle outlets	Covers divergent or angled spray directions
11	Pressure of approximately 50 to 600 bar	Defines a high-pressure operating range
12	Pressure of approximately 100 to 600 bar	Defines a narrower high-pressure range
13	Replaceable liquid storage container	Adds replaceable-reservoir functionality

Claims 11 and 12 overlap substantially. Claim 12 is narrower because it excludes pressures below approximately 100 bar. Both claims address pressure generated by the piston when the spring is released.

Claim 9 is important for soft-mist inhaler technology because it couples a microstructured nozzle with a hydraulic diameter of no more than 10 micrometers. The claim does not require a specific aerosol droplet size. It instead uses nozzle geometry as the principal limitation.

Claim 10 is directed to multi-orifice spray behavior. A product with two nozzle openings pointing in different directions may fall within the claim if the remaining limitations of claim 1 are present.

What do claims 15 through 19 add to the reservoir-pump claims?

Claims 15 through 19 narrow claim 14 as follows:

Claim 15 requires a pointed piston end capable of penetrating the reservoir cap.
Claim 16 requires a spring-driven compression stroke and a spring-tensioning induction stroke.
Claim 17 adds a manually operated latch.
Claim 18 requires at least 50 bar of liquid pressure.
Claim 19 covers liquid medicament for pulmonary inhalation and droplets with a mass median size of no more than 12 micrometers.

Claim 19 is the most directly pulmonary-oriented claim. It does not claim a particular active pharmaceutical ingredient, disease, or dosage regimen. It claims a combination of liquid medicament, an atomizing nozzle, and a specified aerosol particle-size result.

That distinction matters for patent enforcement. A device manufacturer could face a hardware claim without selling a drug. Conversely, a pharmaceutical manufacturer could sell the same active ingredient through a different delivery device without practicing the complete claim combination.

What do claims 21 and 22 protect?

Claim 21 narrows claim 20 by requiring a cylindrical valve member.

Claim 22 narrows claim 20 by requiring a frustoconical valve seat.

These claims protect specific valve geometries. They are technically narrower than claim 20 but may be easier to analyze in an infringement case because the relevant structure can often be identified through teardown, microscopy, or technical drawings.

When did U.S. Patent 5,964,416 lose exclusivity?

U.S. Patent 5,964,416 is listed in public patent databases as expired. Its enforceable patent term ended years ago, subject to any applicable patent-term adjustment or other term calculation recorded by the USPTO.

The patent was issued on October 12, 1999. Under the post-1995 U.S. patent-term framework, the relevant term generally runs 20 years from the applicable U.S. nonprovisional or international filing date, rather than 20 years from the grant date. The underlying family includes an earlier priority history associated with the development of the atomizer platform. Public patent records identify the patent as expired, which means it cannot currently support an infringement action for post-expiration conduct. [1]

Event	Date or status
U.S. patent number	5,964,416
Grant date	October 12, 1999
Technology	Spring-driven high-pressure liquid atomizer
Principal assignee associated with the family	Boehringer Ingelheim International GmbH
Current U.S. status	Expired
Current blocking effect	None from this patent alone

The patent’s expiration does not establish that every later Respimat-related patent has expired. Later patents may cover nozzle manufacturing, cartridge interfaces, dose counters, spring assemblies, housing structures, aerosol performance, or specific formulations.

What is the Orange Book status of U.S. Patent 5,964,416?

U.S. Patent 5,964,416 is a device patent, not an active-ingredient patent. It is not the type of patent ordinarily listed in the FDA Orange Book to identify composition-of-matter protection for a drug.

Orange Book patent listings are generally tied to approved drug products and patents claiming the drug substance, drug product, or approved method of use. A standalone inhaler mechanism is not automatically Orange Book-listed merely because it delivers an FDA-approved drug. [2]

For a soft-mist inhaler product, the relevant Orange Book analysis should distinguish:

The active ingredient patent;
Formulation patents;
Approved method-of-use patents;
Drug-device combination issues; and
Separate device patents that may be outside the Orange Book.

The expiration of U.S. Patent 5,964,416 therefore does not determine when a branded inhaled medicine becomes eligible for abbreviated new drug application competition.

Does the patent create Paragraph IV risk?

No current Paragraph IV risk arises from this expired patent alone.

A Paragraph IV certification is directed to patents listed in the Orange Book for the reference listed drug. An ANDA applicant may certify that an Orange Book-listed patent is invalid, unenforceable, or will not be infringed. [3]

The practical implications are:

Issue	Effect of Patent 5,964,416
Current Paragraph IV challenge	Not applicable to an expired, nonblocking device patent
ANDA eligibility	Not determined by this patent
Device infringement risk	No current risk from this patent
Later device patents	Must be reviewed separately
Formulation patents	May remain relevant independently
Method-of-use patents	May remain relevant independently

A generic inhaled product may still face patent litigation based on later patents, particularly patents covering a cartridge, metering system, formulation, dose counter, nozzle, or approved method of treatment.

What patent landscape surrounds this patent?

The patent sits within a broader soft-mist inhaler landscape. The most relevant patent families fall into six categories.

Early atomizer and pump patents

These patents cover:

Spring-loaded piston drives;
Pressure chambers;
Axially moving inlet valves;
Hollow pistons;
Anti-rotation valve structures;
Reservoir piercing or cap penetration; and
Manual latching systems.

U.S. Patent 5,964,416 is a representative early family member in this category.

Nozzle and microchannel patents

These patents address:

Two-plate nozzle assemblies;
Etched or molded microchannels;
Sub-10-micrometer hydraulic diameters;
Multiple angled outlet openings;
Nozzle plate bonding; and
Droplet-size control.

Nozzle patents are technically significant because a competing pump can avoid one pump claim while still encountering nozzle claims.

Cartridge and reservoir patents

Later families commonly address:

Replaceable cartridges;
Piercable seals;
Reservoir-to-pump interfaces;
Liquid isolation during storage;
Air management;
Cartridge indexing; and
Prevention of incorrect cartridge insertion.

Claim 13 of the patent recognizes the replaceable-container concept, but later patents may claim more specific cartridge and housing structures.

Dose-counter patents

Claim 8 covers a counter with a spindle and slide. Later counter patents may claim:

Actuation-linked indexing;
Remaining-dose displays;
Lockout after the final dose;
Cartridge replacement detection; and
Tamper-resistant counting systems.

Formulation and aerosol-performance patents

These patents may cover:

Specific active ingredients;
Propellant-free aqueous formulations;
Surfactants and stabilizers;
Osmolality and viscosity ranges;
Particle-size distributions;
Pulmonary deposition; and
Storage stability.

They can remain commercially important after device patents expire.

Drug-specific and method-of-use patents

A branded inhaled medicine may have patents directed to:

A particular therapeutic indication;
Once-daily or twice-daily administration;
Combination therapy;
Dose selection;
Patient populations; and
Treatment outcomes.

These patents are distinct from the mechanical claims of U.S. Patent 5,964,416.

How strong was the patent estate?

The patent was technically strong within its original field because it combined several coordinated features rather than claiming only a generic pump. Its principal strengths were:

A spring-driven high-pressure mechanism;
A hollow piston that also functions as a liquid conduit;
An axially moving valve;
A valve-and-piston assembly designed for controlled filling and compression;
High-pressure operation;
Fine nozzle structures; and
Integration with a replaceable liquid container.

The estate was less dominant against products using materially different architectures, such as:

Electrically driven pumps;
Pressurized canisters;
Conventional metered-dose inhalers;
Ultrasonic atomizers;
Mesh nebulizers;
Pumps with separate inlet and outlet valves; or
Reservoirs not penetrated by the piston.

The patent’s current legal strength is zero because it is expired. Its technical influence remains visible in later soft-mist inhaler designs, but enforceability must be assessed patent family by patent family.

Which companies challenged or competed with the technology?

The original technology was associated with Boehringer Ingelheim’s Respimat platform. Competitive products and technologies have included:

Company or platform	Relevant competing approach
Boehringer Ingelheim	Respimat soft-mist inhaler
AstraZeneca	Pressurized metered-dose and dry-powder inhalers
GlaxoSmithKline	Dry-powder, metered-dose, and soft-mist delivery technologies
Novartis	Dry-powder and capsule-based inhalers
Philips Respironics	Nebulizer and aerosol-delivery systems
PARI	Jet and vibrating-mesh nebulizers
Omron and similar device manufacturers	Mesh and electronic nebulization systems

Competition does not necessarily involve a direct legal challenge to this patent. Because the patent has expired, the principal current competition concerns later patents, regulatory approval, manufacturing capability, formulation know-how, and device reliability.

What generic launch risks exist after expiration?

Expiration of U.S. Patent 5,964,416 removes one historical device barrier but does not guarantee a commercially viable generic launch.

The principal remaining risks are:

Later unexpired patents covering the inhaler or cartridge.
Orange Book-listed formulation or method-of-use patents.
FDA requirements for pharmaceutical equivalence and bioequivalence.
Device-drug combination requirements.
Aerosol performance matching, including emitted dose and particle-size distribution.
Manufacturing tolerances for microchannel nozzles.
Container-closure integrity and liquid stability.
Freedom-to-operate issues in foreign jurisdictions.
Trade-secret barriers relating to nozzle fabrication and assembly.
Regulatory review of substitutability where the device is integral to product performance.

A generic product that uses the same active ingredient but a different delivery device may require a complex regulatory strategy. The device must reproduce clinically relevant delivery characteristics, not merely deliver the same nominal dose.

What geographic coverage did the patent provide?

The patent provided rights only in the United States. International family members required separate examination in each jurisdiction.

The main geographic questions for a commercial freedom-to-operate review are:

Whether corresponding European patents remain active;
Whether national validations were maintained;
Whether Canadian, Japanese, Australian, Chinese, or other family members expired;
Whether later continuation or divisional patents exist;
Whether local patent-term extensions applied to drug-related rights; and
Whether a product is manufactured in a country where process patents remain active.

A U.S. expiration does not eliminate foreign patent exposure.

What manufacturing and intellectual-property barriers remain?

The highest barriers are likely to arise from manufacturing precision rather than the expired claims themselves.

Relevant barriers include:

Fabrication of microstructured nozzle plates;
Bonding two nozzle plates without channel blockage;
Reproducible hydraulic diameter;
Spring-force calibration;
Piston and valve dimensional tolerances;
Leak-free pressure-chamber assembly;
Dose-volume consistency;
Cartridge sealing;
Long-term liquid compatibility; and
Automated inspection of nozzle and valve components.

Manufacturing know-how can remain protected as trade secret even after patent expiration. Regulatory data, supplier qualification, tooling, and process validation can also delay market entry.

Key Takeaways

U.S. Patent 5,964,416 covers a spring-driven high-pressure liquid atomizer, not a pharmaceutical active ingredient.
Claim 1 targets the complete atomizer architecture.
Claim 14 focuses on a reservoir, cap-penetrating hollow piston, and reciprocating pump.
Claim 20 targets a hollow-piston pump with an axially controlled, non-rotating valve.
Claims 9, 10, 11, 12, and 19 address nozzle geometry, spray direction, pressure, and pulmonary aerosol performance.
The patent is expired and does not create current U.S. infringement or Paragraph IV exposure.
Later Respimat, formulation, cartridge, nozzle, dose-counter, and method-of-use patents may remain commercially relevant.
A generic launch analysis must separate device freedom to operate from Orange Book, formulation, and regulatory requirements.
The most important historical claim limitations are the hollow piston, axially movable valve, spring-driven compression stroke, high-pressure chamber, and fine atomizing nozzle.

Frequently Asked Questions

Is U.S. Patent 5,964,416 a drug patent?

No. It is primarily a device and pump patent. It claims atomizer structures, valve arrangements, pressure generation, nozzle configurations, and reservoir interfaces.

Does the patent cover the Respimat brand name?

No. The patent does not claim the Respimat trademark. It covers technical structures associated with a type of soft-mist atomizer.

Can a company manufacture a similar soft-mist inhaler today?

The expired patent alone does not prevent manufacture. A current freedom-to-operate review must examine later U.S. and foreign patents covering the complete inhaler, cartridge, nozzle, formulation, and approved use.

Does claim 19 cover all inhaled liquid medicines?

No. Claim 19 requires the claim 14 atomizer architecture, liquid medicament for pulmonary inhalation, and droplets with a mass mean size of no more than 12 micrometers. It is not a general claim to all liquid inhalation medicines.

Are the nozzle claims important after patent expiration?

They remain important for technical and historical analysis, but they are not enforceable against new U.S. conduct after expiration. Similar nozzle structures may still be covered by later patents in the same technical field.

References

United States Patent and Trademark Office. (1999). U.S. Patent No. 5,964,416, Atomizer. https://patents.google.com/patent/US5964416
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book
Electronic Code of Federal Regulations. (2024). 21 C.F.R. § 314.101 and § 314.53, abbreviated applications and patent information. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-314

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Germany	195 36 902	Oct 04, 1995
Germany	195 36 902	Oct 4, 1995

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	003794	⤷ Start Trial
Austria	248028	⤷ Start Trial
Austria	352379	⤷ Start Trial
Australia	7287096	⤷ Start Trial
Australia	730797	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,964,416

Summary for Patent: 5,964,416