Scope, claims, and US patent landscape for US Patent 7,118,552
US 7,118,552 is directed to a mechanically actuated, automatically operable needle safety shield for a syringe. The invention integrates: (1) an inner holder that captures the syringe; (2) an outer axially movable shield biased by a spring; (3) a stop-and-indentation latch that retains the shield in a retracted state until a trigger event occurs; and (4) a trigger that is contacted and disengaged by a syringe component, so the spring drives the outer shield to an extended (needle-covering) position.
What the independent claim actually requires (Claim 1)
Claim 1 is the core mechanical recipe. It requires all of the following, in combination:
- Inner holder with proximal and distal portions, defining an enclosure for insertion of a syringe.
- Outer shield with proximal and distal portions, mounted outward of the inner holder and axially movable relative to the inner holder between:
- retracted position (needle initially exposed), and
- extended position (needle covered).
- Spring bias positioned between:
- a first detent on the inner holder and
- a second detent on the outer shield,
urging the outer shield to the extended position.
- Retaining latch in retracted state:
- inner holder has at least one first opening;
- outer shield has at least one first stop member that is engageable with the first opening when the outer shield is retracted.
- Positive latch engagement in extended state:
- inner holder has at least one first indentation located distal to the first opening;
- the first stop member is engageable with the first indentation when the outer shield is extended.
- Trigger positioned within the inner holder, axially movable relative to the inner holder:
- it can contact the first stop member when engaged with the first opening, and
- it can disengage the first stop member from the first opening, which allows the spring to move the outer shield to the extended position.
Interpretation for scope: Claim 1 is not a generic “safety shield.” It is a specific axial slide + spring + latch architecture where the outer shield’s extension is released by a trigger that mechanically disengages a stop member from an opening during syringe use.
Claim-by-claim scope map (what is broadened, constrained, or added)
Below is how dependent claims tighten or expand the mechanical coverage.
Claim 2
- Places the first and second detents specifically on the distal portions of the inner holder and outer shield.
Scope effect: narrows detent placement but keeps the same latch logic.
Claim 3
- Adds a specific syringe coupling: the safety system includes a syringe with:
- barrel, needle, piston, plunger rod
- plunger rod has a protrusion
- The syringe is operationally coupled to the trigger such that movement of the plunger rod protrusion contacts the trigger to:
- disengage the first stop member from the first opening
- allow spring-driven extension.
Scope effect: defines the release interface as a plunger-rod-driven protrusion contacting the trigger.
Claim 4 (independent-style apparatus claim)
- Recasts the system with the coupling language moved into a full system claim:
- syringe with plunger protrusion
- inner holder/outer shield axial movement
- spring between distal detents
- opening/stop member engagement in retracted state
- indentation engagement in extended state
- plunger protrusion contacts trigger to disengage stop member.
Scope effect: covers the same concept in a different claim grammar. Practically, it reinforces claim coverage over the complete syringe-actuation mechanism.
Claim 5
- Adds a safety clip removably secured to the portion of the plunger rod exposed from the barrel.
- When secured, movement of the plunger rod is prevented.
Scope effect: limits to embodiments with a removable pre-use lock.
Claim 6
- Requires proximal and distal abutment surfaces on outer shield and inner holder in opposing relationship.
- These abutment surfaces prevent the outer shield from moving beyond the extended position.
Scope effect: adds a hard stop to limit shield travel.
Claims 7–8
- Outer/inner holders are generally cylindrical with cross-section circular or elliptical (Claim 7).
- The cylindrical shape can be tapered cylindrical (Claim 8).
Scope effect: constrains geometry but preserves the mechanism.
Claims 9–13 (anti-rotation guidance and sliding features)
- Guide means prevent relative rotation of inner holder and outer shield (Claim 9).
- The inner holder includes a groove corresponding to the stop member so the stop member is slidable (Claim 10 or 12 depending on which inner/outer feature used).
- The outer shield includes grooves corresponding to distal abutment surfaces so those surfaces are slidable (Claim 13).
Scope effect: narrows to embodiments with guided axial motion and defined sliding paths for the stop member and abutment surfaces.
Claim 14
- Adds an inner holder detent: radially inwardly extending distal flange with an upper abutment surface contacted by the syringe to prevent further distal movement of the syringe.
Scope effect: addresses syringe insertion depth and retention behavior.
Claim 15
- Requires syringe engagement and retaining means within the inner holder.
Scope effect: adds retention features.
Claims 16–18 (grip geometry)
- Claim 16: finger grip via at least one radially extending protrusion at proximal end.
- Claim 17: protrusion is a flange around full circumference.
- Claim 18: outer shield lacks proximal finger grip protrusions.
Scope effect: limits ergonomic features.
Claims 19–20 (anti-backward movement and stop member geometry)
- Claim 19: includes plunger rod retaining means preventing backwards movement when the plunger rod is “at least almost at its forwardmost position.”
- Claim 20: stop member extends outwardly then inwardly such that the center of its pivotal axis is inward of the point of engagement with the first opening when engaged.
Scope effect: adds a kinematic geometry detail to the stop member.
What design elements are “must-have” vs “optional”
Must-have under Claim 1 (core coverage)
- Outer shield axially movable and biased by a spring
- A latch that holds the outer shield in retracted state:
- first stop member engages first opening in the inner holder
- A release trigger inside inner holder that:
- contacts the first stop member when engaged with the opening
- disengages the stop member from the opening
- A second latch engagement in extended state:
- first stop member engages indentation distal to the opening
- Trigger release is triggered by user syringe operation either explicitly in dependent claims (Claim 3/4) or implied by the trigger being contactable during operation.
Optional / further limitations (dependent claims)
- Detent placement (Claim 2 and Claim 4)
- Specific syringe structure and protrusion-to-trigger coupling (Claims 3 and 4)
- Safety clip (Claim 5)
- Travel-limiting abutment surfaces (Claim 6)
- Cylindrical/tapered shape and anti-rotation grooves (Claims 7–13)
- Syringe insertion stop flange and retention means (Claims 14–15)
- Finger grip and ergonomics (Claims 16–18)
- Plunger rod backward prevention (Claim 19)
- Specific stop member pivot-axis offset geometry (Claim 20)
Claim scope pressure points (where design-arounds typically succeed)
The patent landscape for needle safety devices usually turns on how the shield is retained and released. For US 7,118,552 specifically, the highest-risk elements for an infringing design are:
- Stop member that engages an opening in retracted position and then engages an indentation in the extended position.
- A trigger that is axially movable inside the inner holder and that disengages the stop member from the opening.
- Axial movement of the outer shield relative to the inner holder (not radial swing).
- Spring-driven extension after latch release.
Design alternatives that keep the same functional safety outcome but change the kinematics can reduce risk:
- Using a different retention geometry (for example, retention by friction brake rather than a stop member engaged in an opening).
- Using a different release mechanism (for example, release by a cam or a pivoting lever that does not disengage a stop member from a first opening).
- Using a different motion type (radial or rotational deployment rather than axial slide).
Those are not “guaranteed” outcomes against any given claim set, but they are the structural features Claim 1 appears to require.
US patent landscape context (device-class neighborhood around axial spring-loaded shields)
US 7,118,552 sits in the crowded needle safety “device” space, where most patents involve:
- a cover/shield moved between needle-exposed and needle-covered states,
- a user-actuated lock-release event,
- an internal latch mechanism tied to syringe motion.
Given the mechanical specificity of Claim 1, the most relevant landscape for freedom-to-operate assessment is dominated by axially deployed safety sleeves with internal latch triggers. Companies typically file improvements around:
- latch geometry (openings/indentations, detents, ratchets)
- coupling to plunger rod travel (protrusion, clip locks, trigger rods)
- anti-backslide and travel-limiting abutments
- guided axial motion to avoid rotation and maintain alignment
Operational conclusion for R&D and design: if a competing product uses axial sleeve deployment, then the key differentiator becomes the exact latch-release architecture. If the competing product uses the same type of opening/indentation stop-member engagement with an internal axial trigger, the likelihood of claim overlap rises sharply.
Competitive and investment implications
If you are licensing or acquiring: what the claims suggest about value
- The invention’s value concentrates in a repeatable mechanical latch-and-trigger architecture rather than in a single ergonomic feature.
- Dependent claims extend enforceability into practical product variants:
- detent placements,
- syringe protrusion coupling,
- safety clip pre-lock,
- travel stops,
- guide features.
If you are developing a “next-gen” platform: where to innovate
- Change how the release event occurs without using the same “stop member disengaged from a first opening by an internal axial trigger.”
- Keep deployment safety compliance while shifting geometry:
- latch architecture,
- motion type,
- release interface.
Key Takeaways
- US 7,118,552 claims a spring-biased, axially sliding safety shield held by a stop member that engages an opening in retracted state and an indentation in extended state.
- A trigger axially movable inside the inner holder contacts and disengages the stop member from the opening, enabling spring-driven extension.
- Dependent claims add enforceable product features: plunger rod protrusion coupling, safety clip pre-lock, travel-limiting abutment surfaces, anti-rotation guidance, syringe insertion stop, and anti-backslide.
- The infringement-risk hotspots are the opening/indentation stop-member latch and the internal axial trigger disengagement sequence tied to syringe actuation.
FAQs
1) Is Claim 1 limited to a specific syringe model?
Claim 1 requires a system “for use with a syringe” and a trigger mechanism that can contact and disengage the first stop member. Claim 1 does not fully lock in the specific syringe component geometry; Claims 3 and 4 add the plunger rod protrusion coupling and syringe element structure.
2) Does the patent cover both retracted and extended latch states?
Yes. Claim 1 requires that the first stop member engages a first opening when retracted and engages a first indentation when extended, creating a two-state latch architecture.
3) What motion does the outer shield use?
Claim 1 requires axial movement between retracted and extended positions. The outer shield moves axially relative to the inner holder.
4) What triggers the release of the shield?
Claim 1 requires an internal, axially movable trigger that disengages the stop member from the first opening. Claims 3 and 4 define a syringe actuation link where a plunger rod protrusion contacts the trigger.
5) Which dependent claims most affect product implementation?
Claim 3/4 (plunger protrusion coupling), Claim 5 (safety clip), Claim 6 (abutment travel stop), Claims 9–13 (anti-rotation and grooves), and Claim 19–20 (anti-backslide and stop-member pivot-axis geometry) most directly map to engineering design choices.
References
[1] US Patent 7,118,552. “Automatically operable safety shield system for use with a syringe.” (Claims provided in user prompt).
