Rotating Plunger Blocking Mechanism for Multi-Dose Drug Delivery

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Solution Overview

Problem

Existing medicament delivery devices require complex user operations and significant hand force for multiple dose delivery, often necessitating manual loading of force devices or multiple steps, making them cumbersome for end users.

Innovation Solution

A mechanism for a medicament delivery device featuring an actuating element that transitions between ready and dosing states, utilizing a blocking structure with axially and circumferentially offset blocking features to enable multiple doses without manual loading, powered by a plunger force device like a spring, and a transmission system to rotate the blocking structure between positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a medicament delivery device is designed to perform multiple medicament delivery operations, then the device can deliver multiple doses, but it requires more operation steps and significant hand force from the end user

Engineering Contradiction:
Improvemultiple doses delivery capabilityVSAvoidoperation steps and hand force required
Core Design Contradiction:
Duration of action of moving objectVSEase of operation

Solution Approach 1:

The blocking structure is pre-configured with multiple blocking features at different angular positions to anticipate and enable multiple dosing operations. The transmission mechanism is pre-arranged to automatically rotate the blocking structure to the correct position for each dose, eliminating the need for manual reconfiguration between doses.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The device performs self-service by automatically rotating the blocking structure through the transmission mechanism driven by the actuating element. The system uses its own operational components (actuating element, transmission, blocking structure) to automatically position itself for subsequent doses without requiring external manual intervention beyond the initial actuation.

Inventive Principle:
Principle #25Self-service

2Extent of automation

If a medicament delivery device is arranged with a force device configured to push the piston forward, then the medicament delivery can be automated, but the end user needs to load the force device manually before performing the medicament delivery operation

Engineering Contradiction:
Improveplunger movement automationVSAvoidloading procedure complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The blocking structure is merged with the transmission mechanism and the actuating element system. The same actuating element that drives plunger movement also, through the transmission, rotates the blocking structure. This merging eliminates the need for separate manual loading of the force device, as the automated plunger drive system inherently controls the blocking structure positioning.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The actuating element serves multiple functions: it directly drives the plunger proximal movement for medicament expulsion and simultaneously, through the transmission mechanism, rotates the blocking structure to the correct angular position. This multi-functionality eliminates the need for separate manual loading operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Extent of automation

If a blocking structure is used to control plunger movement for multiple doses, then automated multi-dose delivery is enabled, but the mechanism requires axially and circumferentially offset blocking features

Engineering Contradiction:
Improvemulti-dose delivery automationVSAvoidblocking structure design complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The blocking structure employs asymmetric blocking features that are axially offset and circumferentially offset from each other. This asymmetric design allows the single blocking structure to selectively engage with the plunger at different angular positions, enabling multiple doses with a single rotating component rather than requiring multiple identical blocking structures.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The blocking features are positioned in multiple dimensions - both axial offset (different distances from the rotation axis) and circumferential offset (different angular positions). This multi-dimensional arrangement allows a single blocking structure to control multiple dosing events through rotation, transforming a potentially complex multi-component system into a more compact multi-dimensional design.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables seamless delivery of multiple medicament doses with reduced user effort by automating the plunger movement, eliminating the need for manual force application and simplifying the operation process.

Implementation Method 1

a plunger force device arranged to force the plunger in a proximal direction along the longitudinal axis

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP4188483B1Mechanism for medicament delivery device, and medicament delivery device comprising mechanism
Publication Date: 2026.02.18 SHL MEDICAL AG
  • EP4188483B1 patent drawingFigure 1a~1c
  • EP4188483B1 patent drawingFigure 2~3
  • EP4188483B1 patent drawingFigure 4a~4c

AI summary

A mechanism (12a-12e) comprising an actuating element (24a-24e); a longitudinal axis (22); a plunger (26) comprising at least one first blocking feature (38) and at least one second blocking feature (40); a plunger force device (28); a blocking structure (30) rotatable about the longitudinal axis (22) from a first blocking structure position (68), in which one of the at least one first blocking feature (38) is allowed to pass by the blocking structure (30) and one of the at least one second blocking feature (40) is prevented from passing by the blocking structure (30), and a second blocking structure position (70), in which one of the at least one second blocking feature (40) is allowed to pass by the blocking structure (30); and a transmission (32) configured to transmit a transition of the actuating element (24a-24e) between a ready state (50) and a dosing state (64) to a rotation of the blocking structure (30) from the first blocking structure position (68) to the second blocking structure position (70).