Injection Pen Dose Correction via Segmented Driver Ratchet
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Solution Overview
Problem
Existing medication injection pen devices often fail to simultaneously provide intuitive and efficient mechanisms for dose correction and last dose control, requiring cumbersome additional steps and complex manufacturing processes.
Innovation Solution
A medication injection pen design featuring a housing with a dose set knob, a brake assembly with a ratchet member, and a driver or lead screw that engages with external teeth to prevent rotation during dose setting and allow rotation during injection, enabling simple assembly and customization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If prior art devices use snap fit components together to secure components, then assembly is secure, but manufacturing requires tight tolerances and complex processes
Solution Approach 1:
The driver is segmented with separate teeth that engage with the ratchet member, allowing modular assembly without snap-fitting. This segmentation enables secure component attachment through controlled engagement surfaces while simplifying manufacturing tolerances.
Solution Approach 2:
The invention extracts the snap-fit mechanism entirely and replaces it with a ratchet-based engagement system. The driver teeth directly engage with the ratchet member, eliminating the need for separate snap-fit components and their associated tight tolerance requirements.
2Reliability
If prior art devices use one-way ratchet systems for dose correction, then dose control is achieved, but the system is difficult for users to access and requires substantial manufacturing processes
Solution Approach 1:
The ratchet member is merged with the brake assembly, creating a unified component that provides both the one-way ratchet function for dose control and the brake function for injection. This integration simplifies the overall structure and makes the dose correction mechanism more accessible to users through the dose set knob interface.
Solution Approach 2:
The brake assembly with integrated ratchet member serves multiple functions: it provides one-way ratchet engagement for dose correction, acts as a brake during injection, and interfaces with the dose set knob. This multi-functionality reduces the number of separate components and simplifies user interaction.
3Adaptability or versatility
If prior art devices provide dial back and last dose control features, then functionality is improved, but additional steps are required making operation cumbersome
Solution Approach 1:
The brake assembly with integrated ratchet member provides multiple dose control functions including dial-back and last-dose control through a single unified mechanism. The driver teeth engagement with the ratchet member enables both dose correction and prevention of over-dosing without requiring separate operational steps.
Solution Approach 2:
The ratchet member is pre-configured with engagement surfaces that automatically enable dose correction and last-dose control functions. The driver teeth are designed to engage with specific ratchet surfaces that provide tactile feedback and automatic stopping, eliminating the need for users to learn complex operational sequences.
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
The design allows for intuitive dose setting and correction without additional steps, ensuring accurate dosing and eliminating the need for complex snap-fitting components, thereby improving user experience and manufacturing efficiency.
Implementation Method 1
A brake assembly is disposed in the housing has a ratchet member. A driver includes at least one external tooth engaging the ratchet member. The engagement between the ratchet member and the at least one external tooth substantially prevents the driver from rotating with respect to the dose set knob during dose setting and dose correcting. The engagement between the ratchet member and the at least one external tooth allows the driver to rotate with the dose set knob during an injection.
Data Source
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AI summary
The invention provides a medication injection pen, comprising a cartridge housing (17) for housing a medication cartridge (18); a housing (1) connected to said cartridge housing (17); a dose set knob (2) rotatable with respect to said housing (1); a dose stop member (71) to prevent the setting of a dose that is larger than the remaining amount of medication in the cartridge (18), a brake assembly (36) disposed in said housing (1) and having a ratchet disk (43); and a driver (21); and a setback member (9) provided co-axially around said driver that is rotatably fixed to the setback member (9) and axially movable relative to the setback member (9), wherein the setback member (9) is coaxial with and surrounded by the dose set knob (2), the dose stop member (71) comprises threads (72) configured to engage with corresponding threads (65) provided on an inner surface (66) of the dose set knob (2).