Injection Device Cap Removal via Rotational Lifting Pole
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing injection devices with caps that require axial movement to avoid needle rotation during cap retraction can be difficult for impaired or elderly users to operate, as they often necessitate high force for initial disengagement due to internal friction and sealing issues.
Innovation Solution
The injection device incorporates pivotally arranged lifting poles within the cap that convert rotational movement into axial displacement, allowing for easier cap removal by adjusting the length and inclination of the poles to distribute force effectively, ensuring cap detachment irrespective of rotational direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cap is designed to be removed by axial movement only, then relative rotational movement between the needle shield and the needle is avoided, but the force required for cap removal increases significantly
Solution Approach 1:
The cap removal mechanism transitions from a static axial-only constraint to a dynamic system where rotational movement is converted into axial displacement through lifting poles. The lifting poles pivot from an initial inclined position to a final axial position, dynamically adapting the movement type during the removal process.
Solution Approach 2:
The lifting pole acts as an intermediary element between the cap and the housing. It translates the rotational input from the user into axial displacement of the cap, mediating the force transmission and movement conversion while reducing the direct force requirement on the user.
2Reliability
If the cap is tightly secured to the housing, then the needle shield and needle remain protected during storage, but high force is required for initial disengagement
Solution Approach 1:
The lifting pole mechanism provides a dynamic force multiplication effect. During the initial disengagement phase, the lifting pole's inclined geometry creates a mechanical advantage that reduces the force required to overcome the tight securing between cap and housing.
Solution Approach 2:
The lifting pole introduces a rotational dimension to the cap removal process, converting the one-dimensional axial pull into a two-dimensional rotational-to-axial conversion. This adds a new degree of freedom that reduces the force requirement in the axial direction.
3Ease of operation
If a lifting pole with longer stroke is used, then the cap can be removed more easily, but the total length of the lifting pole increases
Solution Approach 1:
The lifting pole utilizes dynamic pivoting action rather than a simple linear translation. The pole rotates from an inclined initial position to an axial final position, creating an effective stroke that is longer than the physical pole length would suggest, thereby avoiding the need for an excessively long pole.
Solution Approach 2:
The lifting pole's pivoting motion follows a curved arc rather than a straight line. This curved path allows the pole to achieve greater axial displacement through rotational movement, effectively converting rotational distance into linear displacement without requiring a proportionally long pole.
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
This design reduces the force required for cap removal by leveraging lever mechanics, making it easier for users to detach the cap without relative rotational movement between the needle and needle shield, thus maintaining sterility and improving user friendliness.
Implementation Method 1
The first lifting pole is arranged to bear against the abutment surface at a distal end when the cap is in a fully attached position on the housing and the first lifting pole extends from the abutment surface to the pivotal connection to the cap along an axis which is inclined in relation to a longitudinal axis of the housing when the cap is in said fully attached position. Relative rotational movement between the cap and the housing in a first direction around said longitudinal axis will cause the distal end of the first lifting pole to engage with the engagement structure and bring about an alignment of the first lifting pole with the longitudinal axis of the housing thus causing axial displacement of the cap relative to the housing
Data Source
Figure 1
Figure 2A~2B
Figure 2C~2D
AI summary
The invention relates to an injection device (1) comprising a housing (2) having an abutment surface (5) provided near a proximal end, said abutment surface extending at least partially around a perimeter of said housing and at least one engagement structure (6) provided at the abutment surface, wherein the injection device further comprises: a cap (7) provided with an opening (10) at a distal end (9); wherein a first lifting pole (11) is pivotally arranged within the cap, said first lifting pole being pivotally connected to the cap and being arranged to bear against the abutment surface in a fully attached position on the housing; and wherein relative rotational movement between the cap and the housing around a longitudinal axis will cause a distal end of the first lifting pole to engage with the engagement structure thus causing axial displacement of the cap relative to the housing towards a detached position of the cap.