United States Patent 5,944,329: Claim Scope, Validity, Expiration, and Patent Landscape

U.S. Patent No. 5,944,329 is not a drug patent. It covers a mechanical locator-and-mount apparatus for machining parts. The core invention combines a circumferential kinematic mount, alternating connection elements and grooves, and a reversible locator having projections that engage the grooves. The claims are directed to apparatus configurations rather than a method of machining, a particular workpiece, or a pharmaceutical product.

The patent’s commercial relevance is primarily historical. Its claim set is narrow in geometry and component arrangement, and its U.S. patent term has likely expired based on the 1990s filing and 1999 grant chronology. No Orange Book listing, FDA exclusivity, Paragraph IV pathway, biosimilar issue, or drug-related regulatory status applies.

What technology does U.S. Patent 5,944,329 protect?

The patent protects a modular workholding system for positioning parts during machining. Its architecture has two principal components:

A kinematic mount.
One or more removable locators that support a workpiece.

The mount uses grooves and connecting elements arranged around its circumference. The locator has projections on both of its opposing surfaces. The projections fit into the mount grooves, allowing the locator to be positioned with either surface facing the mount.

The claims indicate that the system is intended to provide repeatable positioning while allowing rapid locator replacement or reorientation. The claimed apparatus also supports configurations in which two locators are placed on the same mount at the same time.

What is the scope of independent claim 1?

Claim 1 is the principal scope-defining claim. It requires every element below:

Claim element	Required limitation
Apparatus type	Locator and mount apparatus for machining parts
Mount	Kinematic mount
Mount surface	Top surface
Mount connection structure	Either a connecting means or structure receptive to a connecting means
Mount positioning structure	Grooves
Arrangement	Connecting or receptive structures and grooves alternate circumferentially
Locator	At least one locator
Locator connection structure	Either a connecting means or structure receptive to a connecting means
Workpiece interface	Part support means
Locator positioning structure	Multiple projections on both locator surfaces
Functional relationship	Projections and grooves position the locator when disposed on the mount
Reversibility	The locator can contact the mount with either surface

The claim is a combination claim. A device must contain the mount, locator, alternating circumferential arrangement, dual-sided projections, and projection-groove positioning relationship to fall within the literal scope of claim 1.

A conventional fixture with only one-sided locating features would not satisfy the express requirement for projections on both locator surfaces. A system using a flat plate and independent dowel pins may also avoid literal infringement if it lacks the claimed alternating circumferential connection and groove arrangement.

How do claims 2 through 11 narrow the patent scope?

Claims 2 through 11 add specific hardware configurations.

Claim	Added limitation	Scope effect
2	Magnets on the mount and magnet-attractive locator material	Limits the system to magnetic retention
3	Rare-earth magnets	Narrows claim 2 to rare-earth magnetic elements
4	V-grooves	Requires V-shaped grooves
5	Three V-grooves at 120-degree intervals	Requires a three-point radial pattern
6	Six V-grooves at 60-degree intervals	Requires a six-point radial pattern
7	Adjustable magnet mounting system	Adds magnet-position adjustment
8	Steel-ball projections	Requires steel balls as projections
9	Three steel balls at 120-degree intervals	Requires a three-point ball arrangement
10	Retainer ring as part support	Limits the workpiece support structure
11	Part-support clamp	Limits the support structure to a clamp arrangement

These claims are progressively narrower. For example, a system using permanent magnets but ceramic or non-steel locating projections may potentially avoid claim 8 while remaining within claim 2, assuming all claim 1 elements are present. A mount with six V-grooves may fall within claim 6 but not claim 5, which requires three V-grooves.

Claim 3 is narrower than claim 2 but does not necessarily require a particular rare-earth composition. The term “rare earth magnets” would ordinarily encompass commercially recognized rare-earth magnet types, subject to the specification and prosecution history.

What do claims 12 through 16 protect?

Claims 12 through 16 address dual-locator operation.

Claim 12 requires a first locator and a second locator that are simultaneously disposed on the same mount. This is a significant narrowing limitation because the claim is directed to concurrent use rather than merely the capability of using multiple interchangeable locators.

Claims 13 and 14 define the first locator. It must include:

A structure for carrying a part;
Multiple projections;
Multiple offset bosses;
Magnet-clearance holes;
Projection-clearance holes.

Claim 14 specifies three of each principal feature, arranged at 120-degree intervals.

Claims 15 and 16 define the second locator. The second locator must include:

A structure for carrying a part;
Multiple projections;
Multiple offset bosses;
Offset-boss clearance holes;
Projection-clearance holes.

Claim 16 specifies three of each feature, also arranged at 120-degree intervals.

The distinction between the first and second locator configurations appears to concern the location and function of clearance holes. The claimed holes permit two locators to occupy the mount simultaneously without interference from magnets, projections, or bosses.

What claim construction issues are likely to matter?

The following terms would likely control infringement analysis:

“Kinematic mount”

A kinematic mount generally constrains a workpiece or fixture through defined contact points and repeatable geometric constraint. The claim does not merely require a flat support plate. The accused mount would likely need a structure that provides repeatable positioning through the claimed grooves and projections.

“Alternating circumferentially”

This language requires a circumferential sequence in which connection or receptive structures alternate with grooves. A mount where all magnets are grouped in one area and all grooves in another may not satisfy this limitation.

“Projections on both locator surfaces”

The requirement applies to both opposing locator surfaces. Projections on only the working face are insufficient for literal claim 1 infringement.

“Either surface contacting said mount”

The locator must be usable with either surface against the mount. This limitation supports the patent’s reversible-locator concept.

“Connecting means” and “means receptive to a connecting means”

These phrases may invoke means-plus-function analysis under 35 U.S.C. § 112(f), depending on the specification and prosecution history. If so, the corresponding structure disclosed in the patent and its equivalents would define the enforceable scope. The specification would be essential to determine whether the claims cover only magnets and magnetically attractive materials or broader connection technologies.

“Part support means”

Claims 10 and 11 identify examples of the support structure, but claim 1 is broader. A retainer ring or clamp is not necessarily required by the independent claim unless the dependent claim is asserted.

What is the difference between literal infringement and the doctrine of equivalents?

Literal infringement requires the accused apparatus to satisfy every limitation of the asserted claim. For claim 1, the most important literal questions would be:

Does the mount have the required alternating circumferential pattern?
Are grooves present?
Are projections located on both locator surfaces?
Do the projections and grooves position the locator?
Can either locator surface contact the mount?
Does the apparatus have the claimed connecting or receptive structure?

The doctrine of equivalents could become relevant where an accused product uses a technically different structure that performs substantially the same function in substantially the same way to achieve substantially the same result. The “all elements” rule still applies. A substantial departure from the reversible dual-sided projection architecture could weaken an equivalence theory.

How strong is the patent estate?

The patent estate appears limited to a single U.S. patent and the claim set reproduced by the user. The claims are technically specific and structurally dense. That produces a mixed enforcement profile:

Factor	Assessment
Core concept	Clear and commercially understandable
Claim breadth	Moderate to narrow
Design-around exposure	High
Dependence on specific geometry	High
Dependence on magnets	Present in several dependent claims
Dependence on V-grooves	Present in dependent claims
Dual-locator coverage	Narrow and configuration-specific
Pharmaceutical relevance	None
Current U.S. exclusionary value	Likely none if the patent term has expired

Claim 1 is broader than the dependent claims but still requires a particular combination of circumferentially alternating structures and reversible dual-sided projections. Competitors could design around the claims by changing the locating interface, eliminating reversible use, using non-circumferential positioning elements, or using a different retention mechanism.

When did U.S. Patent 5,944,329 lose exclusivity?

The patent was granted on August 31, 1999. Its exact expiration date depends on the applicable patent-term regime, the earliest effective nonprovisional filing date, any patent-term adjustment, and any terminal disclaimer.

Because the patent originated from the 1990s, its term would ordinarily be calculated under the 20-year-from-effective-filing-date framework applicable to post-June 8, 1995 applications, unless an earlier priority or other term rule applies. A 1999 grant date alone does not establish the expiration date. The public patent record, including the front page, continuity data, and USPTO Patent Center, controls the final calculation. See 35 U.S.C. § 154 and USPTO, “Patent Term Calculator.”

The practical business conclusion is that a 1999-issued mechanical patent of this vintage is no longer a normal current blocking right unless an unusual term adjustment or other legally operative circumstance extended its term.

What is the FDA and Orange Book status?

U.S. Patent 5,944,329 has no FDA or Orange Book status because it does not claim a drug, active pharmaceutical ingredient, formulation, method of treatment, dosage form, biologic, or manufacturing process for a regulated medicine.

Regulatory category	Status
FDA product approval	Not applicable
Orange Book listing	Not applicable
Hatch-Waxman exclusivity	Not applicable
Paragraph IV challenge	Not applicable
Biosimilar litigation	Not applicable
REMS-related exclusivity	Not applicable
Pediatric exclusivity	Not applicable
Generic-drug launch risk	Not applicable
Pharmaceutical formulation protection	None

The patent cannot block an ANDA, 505(b)(2) application, or biosimilar application because its claims are unrelated to a pharmaceutical product.

What patent landscape surrounds the claimed technology?

The relevant landscape is mechanical workholding and precision fixturing rather than drug patents. Competing technologies would likely fall into these categories:

Kinematic and quasi-kinematic fixtures

These systems use defined contact points, balls, grooves, cones, pins, or other constrained interfaces to achieve repeatable repositioning. A competitor using a different contact geometry may avoid the specific projection-and-groove combination.

Magnetic workholding systems

Magnetic bases and ferromagnetic locators are central to claims 2, 3, and 7. Relevant competing designs may use vacuum retention, mechanical clamps, pneumatic retention, hydraulic clamping, or mechanical fasteners.

Modular fixture plates

Modular plates may support interchangeable nests, pallets, dowel systems, or locating blocks. A plate with fixed dowel-hole patterns may present a different claim profile from the circumferential alternating arrangement required by claim 1.

Reversible locator systems

The reversible feature is a central technical limitation. Systems with only one usable locator orientation may avoid the express dual-surface requirement.

Multi-part or dual-locator fixtures

Claims 12 through 16 focus on two locators used simultaneously. Competing systems may use separate independent mounts, linear indexing, stacked fixture plates, or non-overlapping nests.

What manufacturing and intellectual-property barriers remain?

The patent itself does not create a significant current manufacturing barrier if its U.S. term has expired. The principal barriers are likely engineering and commercial:

Precision machining of V-grooves and projection interfaces;
Repeatable magnet placement;
Control of magnetic force and workpiece interference;
Wear resistance at ball-and-groove contacts;
Tolerance control for interchangeable locators;
Clearance design for simultaneous locator use;
Protection of know-how relating to calibration and fixture setup.

A manufacturer could still face rights under later patents, foreign counterparts, unexpired continuation patents, design patents, trade secrets, or third-party rights covering improved fixture geometries. Those rights cannot be determined from the supplied claims alone.

Are there Paragraph IV challenges, settlements, or licensing deals?

No pharmaceutical Paragraph IV analysis applies. The supplied claim set does not identify any generic-drug challenger, biosimilar applicant, FDA sponsor, Hatch-Waxman litigation, or drug patent settlement.

A licensing assessment would require the patent’s assignment history, recorded licenses, security interests, litigation docket, and any related continuation or foreign-family filings. The claims alone do not establish whether the patent was licensed or commercially transferred.

What geographic coverage does the patent provide?

The patent claims provide U.S. rights only. Any protection outside the United States would require separately issued foreign patents or regional rights. A U.S. patent does not automatically create enforceable rights in Canada, Europe, Japan, China, or other jurisdictions.

Foreign family members, if any, would require separate review for:

Filing dates;
Grant status;
Claim scope;
Local expiration;
Maintenance-fee compliance;
Assignment and licensing;
Litigation and opposition history.

Key Takeaways

U.S. Patent 5,944,329 is a mechanical machining-fixture patent, not a drug patent.
Claim 1 requires a kinematic mount, alternating circumferential connection or receptive structures and grooves, and a reversible locator with projections on both surfaces.
Claims 2 through 11 narrow the system through magnets, rare-earth magnets, V-grooves, steel balls, retainer rings, clamps, and adjustable magnet mounts.
Claims 12 through 16 cover simultaneous use of two specially configured locators.
The claim set is structurally specific and has substantial design-around exposure.
FDA approval, Orange Book listing, Paragraph IV litigation, biosimilar risk, and pharmaceutical exclusivity do not apply.
The exact patent expiration date requires the official continuity and term records, but a 1999-issued patent of this type is unlikely to retain ordinary current U.S. exclusionary value.
Current freedom-to-operate analysis should focus on later patents, continuations, foreign family members, and competing fixture patents.

FAQs

Is U.S. Patent 5,944,329 a pharmaceutical patent?

No. It covers a locator and mount apparatus used to position parts during machining.

Can a magnetic fixture infringe U.S. Patent 5,944,329?

Potentially, but magnetic retention alone is insufficient. The fixture would also need to satisfy the applicable mount, groove, projection, circumferential arrangement, and reversible-locator limitations.

Does a three-point kinematic mount automatically infringe the patent?

No. Three-point geometry alone does not establish infringement. The accused system must satisfy all limitations of an asserted claim, including the claimed circumferential arrangement and dual-sided locator projections.

Do claims 12 through 16 cover any two fixtures used together?

No. They require specific first and second locator structures, including projections, offset bosses, clearance holes, and, in the narrower claims, three-part 120-degree arrangements.

Is a Paragraph IV certification required to challenge this patent?

No. Paragraph IV certifications apply to patents listed for approved drug products. This patent is directed to mechanical machining equipment and has no Orange Book function.

Sources:

U.S. Patent No. 5,944,329, “Locator and Mount Apparatus for Machining Parts,” claims 1-16 (1999).
United States Code, 35 U.S.C. § 154, “Contents and Term of Patent; Provisional Rights.”
United States Patent and Trademark Office. (n.d.). “Patent term adjustment.” https://www.uspto.gov/patents/laws/patent-term-calculator
U.S. Food and Drug Administration. (n.d.). “Approved drug products with therapeutic equivalence evaluations.” Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
United States Code, 35 U.S.C. § 112, “Specification.”

Details for Patent: 5,944,329

Summary for Patent: 5,944,329