Telescopic Tube Assembly With Dual Locking Against Loosening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional telescopic grip mechanisms for gardening tools, such as tree branch shears and pruning saws, often become loose due to external forces, restricting extension distance and posing safety risks, as they lack sufficient pressing force to maintain a stable positioning effect.
Innovation Solution
A dual positioning mechanism comprising a first tube, a second tube, a first positioning unit with a handle and cam system, and a second positioning unit with a pin, elastic member, and button, allowing for adjustable length locking through a combination of manual and elastic force, preventing loose alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional cam handle positioning mechanism is used, then the structure is simple, but the positioning reliability deteriorates as it easily becomes loose under external forces
Solution Approach 1:
The positioning mechanism is divided into two independent units: a first positioning unit with a cam handle for macro positioning, and a second positioning unit with a pin and elastic member for micro positioning. Each unit performs a specific positioning function, and together they provide reliable multi-stage positioning that prevents loosening under external forces.
Solution Approach 2:
The pin is preliminarily positioned by the first positioning unit before the second positioning unit engages. The elastic member pre-loads the pin into the positioning hole, creating initial contact and alignment. This preliminary action ensures that when the handle is operated, the positioning is already partially established, improving reliability.
2Length of moving object
If a conventional cam handle positioning mechanism is used, then the device complexity is low, but the extension distance is restricted due to lack of pressing force
Solution Approach 1:
The second positioning unit is nested within the first positioning unit. The pin passes through the base of the first positioning unit and engages with the positioning hole in the movable tube. This nested arrangement allows the inner pin mechanism to provide additional pressing force without increasing the overall external dimensions, enabling greater extension distance while maintaining compact structure.
Solution Approach 2:
The cam portion of the handle uses a curved cam surface that converts rotational motion into linear pressing force. The curved geometry amplifies the pressing force applied to the pin, enabling the mechanism to maintain strong positioning force over extended distances without requiring excessive mechanical complexity.
3Stability of the object's composition
If a conventional cam handle positioning mechanism is used, then the structure is simple, but the positioning stability deteriorates under external forces
Solution Approach 1:
The first positioning unit (cam handle) and second positioning unit (pin with elastic member) are merged into a single integrated mechanism. The cam handle operates the pin, which in turn engages with the positioning hole. This merging of functions creates a unified positioning system where both units work together to provide stable positioning that resists external forces, while avoiding the need for completely separate mechanisms.
Solution Approach 2:
The positioning mechanism combines rigid components (handle, base, pin) with an elastic component (elastic member). The elastic member provides flexible compensation for misalignment and maintains constant contact force, while the rigid components provide structural strength. This composite approach enhances positioning stability under external forces without requiring overly complex rigid structures.
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 dual positioning mechanism ensures a secure and adjustable telescopic tube assembly that reduces operational risks and maintains stability even under external forces, enabling longer extension distances and meeting the needs of long-distance use.
Implementation Method 1
The elastic member is disposed between the cover and the pin for providing an elastic force to push the pin in a direction away from the cover
Implementation Method 2
The handle has a handle portion and a cam portion connected with the handle portion and pivoted to the base, such that the handle is pivotable relative to the base between a lock position where the cam portion of the handle pushes the first positioning portion of the base
Data Source
AI summary
A telescopic tube assembly includes a first tube and a second tube penetrated in the first tube. A handle is pivoted to a base sleeved on the first tube and pressed against the second tube when the handle is locked. Further, a pin is provided between the base and a cover mounted to the base, and a button is horizontally disposed in the base. When the button is pressed, the pin is pushed by the button to be disengaged from the second tube, such that the length of the second tube can be adjusted. When the button is released, the pin is pushed by an elastic member to be engaged with the second tube for locking the second tube in a desired length. By means of the dual lock design, the telescopic tube assembly of the present invention provides good positioning effect to reduce operational risk.