Invaginating Device Actuator Control
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Solution Overview
Problem
Existing invaginating devices lack a mechanism to control relative axial movement between the outer tube and the inner elongate member, leading to inefficient invagination and potential sealing issues during pressurization of the annular gap.
Innovation Solution
An invaginating device with an inner elongate member, an outer flexible tube sealed at both axial ends, and an actuator that is movable relative to the inner elongate member to extend or retract the outer flexible tube, ensuring controlled invagination and maintaining pressure within the radial gap using a non-compressible fluid or pressurized fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer flexible tube is sealed at both axial ends to the inner elongate member, then pressure can be maintained within the radial gap, but relative axial movement between the outer tube and inner elongate member cannot be controlled
Solution Approach 1:
The outer flexible tube is divided into multiple axially-spaced sealed regions, with unsealed portions between them. This segmentation allows the actuator to engage with specific unsealed portions to control axial movement of discrete sections of the outer tube, enabling controlled invagination while maintaining sealing integrity in each sealed region.
Solution Approach 2:
The device transitions from a static sealed structure to a dynamic system where the actuator can move relative to the inner elongate member to extend or retract the outer flexible tube. This dynamic capability allows controlled adjustment of the outer tube's axial position while the sealed regions maintain pressure containment.
2Ease of operation
If the outer flexible tube is made extendable and retractable, then invagination control is improved, but the complexity of the device increases due to the actuator mechanism
Solution Approach 1:
The actuator is positioned within the radial gap between the inner elongate member and the outer flexible tube, nesting the actuation mechanism within the existing device structure. This eliminates the need for external actuation mechanisms and reduces overall device complexity while maintaining control capability.
Solution Approach 2:
The actuator serves as an intermediary element that translates axial movement into controlled extension and retraction of the outer flexible tube. By engaging with unsealed portions of the outer tube, it provides a simple mechanical interface for invagination control without requiring complex mechanisms.
3Length of moving object
If pressurized fluid is used in the radial gap, then the outer flexible tube can be extended, but sealing between the outer tube and inner elongate member becomes more critical
Solution Approach 1:
The outer flexible tube is divided into multiple axially-spaced sealed regions created by seals at different axial positions. This segmentation allows pressurized fluid to be contained within discrete axial segments, reducing the consequences of potential sealing failures and enabling extension control through pressure differential across sealed regions.
Solution Approach 2:
Different axial regions of the outer flexible tube have different sealing characteristics - some regions are sealed to the inner elongate member while others are unsealed to allow actuator engagement. This local differentiation of sealing quality enables both pressure containment where needed and actuator access where required.
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 device effectively ensheaths and relocates objects by controlling the invagination of the outer flexible tube, preventing buckling and maintaining pressure, thus ensuring efficient capture and protection of objects during insertion and removal.
Implementation Method 1
an actuator that: movable relative to the inner elongate member; and engageable with the outer flexible tube to extend the outer flexible tube relative to the first axial end of the inner elongate member
Implementation Method 2
fluid within the radial gap defined between the inner elongate member and the outer flexible tube, which fluid is either: (i) pressurized; or (ii) a non-compressible fluid
Data Source
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AI summary
An invaginating device (10) includes an inner elongate member (12) and an outer flexible tube (14) with invaginated axial ends. The outer flexible tube is: disposed at a first axial end of the inner elongate member; concentric with the inner elongate member; sized to provide a radial gap (24) there between; sealably connected at the axial ends of the outer flexible tube to the inner elongate member, with the axial spacing between such sealed axial ends being less than the axial length of the outer tube; and extendable to protrude from the first axial end of the inner elongate member and retractable to reduce such protrusion from the first axial end of the inner elongate member. Fluid contained within the radial gap (24) defined between the inner elongate member and the outer flexible tube is either pressurized or a non-compressible fluid. An actuator (16) is: movable relative to the inner elongate member; and engageable with the outer flexible tube to extend the outer flexible tube relative to the first axial end of the inner elongate member.