Telescopic Pruner With Internal Pulling And Deflection Pulleys
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Solution Overview
Problem
Existing telescopic hand tools with pulling means visible and guided in grooves or outside the tubes face operational complexity and potential for direct material contact, leading to fretting and reduced ease of use.
Innovation Solution
A telescopic hand tool design with a pulling means arranged substantially inside the tubes, utilizing deflection pulleys and a pull sleeve, with portions of the pulling means guided within channels and pulleys to minimize visibility and friction, ensuring easy operation and protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the pulling means is arranged outside the tubes or in visible grooves, then the structure is simpler, but the ease of operation deteriorates due to direct material contact and fretting
Solution Approach 1:
The pulling means is nested inside the tubes, specifically arranged in the inner tube which is slidable within the intermediate tube, which is slidable within the outer tube. This nested arrangement hides the pulling means from direct view and protects it from direct material contact between tubes, eliminating fretting while maintaining operational simplicity through the integrated design
Solution Approach 2:
The pulling means acts as an intermediary element that transmits force from the back handle through the tubes to the tool head. By arranging it inside the tubes with deflection pulleys, it mediates the force transmission while being protected from direct tube-to-tube contact, solving the fretting issue while maintaining operational effectiveness
2Reliability
If the pulling means is arranged inside the tubes, then the protection from damage is improved, but the device complexity increases due to the need for deflection pulleys and channels
Solution Approach 1:
Deflection pulleys are introduced as intermediary elements that redirect the pulling means inside the tubes. These pulleys enable the pulling means to change direction and be guided through the tube structure without requiring complex guiding mechanisms, thus providing protection while managing structural complexity
Solution Approach 2:
The pulling means is designed as a flexible element (cord or band) that can be guided through channels and around pulleys inside the tubes. This flexible nature allows it to be protected within the tube structure while maintaining the ability to transmit force, balancing protection with operational simplicity
3Adaptability or versatility
If three tubes are used, then the adjustable length range is improved, but the device complexity increases
Solution Approach 1:
The three tubes are arranged in a nested configuration where the inner tube slides within the intermediate tube, which slides within the outer tube. This nested arrangement enables a wide adjustable length range from fully extended to fully retracted positions while using a compact space, achieving versatility without proportionally increasing overall complexity
Solution Approach 2:
The three-tube structure provides multi-functionality by enabling the tool to operate at various length configurations (extended for reach, retracted for storage). The same tube structure serves both the telescopic length adjustment function and the housing function for the pulling means, achieving versatility without requiring separate dedicated components for each function
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 easy and safe operation by minimizing direct contact between tube materials, reducing fretting, and enhancing protection of the pulling means from damage, while maintaining a wide range of adjustable lengths.
Implementation Method 1
A number of deflection pulleys is arranged at the back ends of the tubes and at the front ends of the outer tube and intermediate tube, wherein the deflection pulleys are provided for redirecting the pulling means
Implementation Method 2
A hoist pulley is slidable within the inner tube and connected to the tool head by at least one rod, band, or further cord, wherein the hoist pulley is provided for redirecting the pulling means such that an operator force is amplifiable
Implementation Method 3
the hoist pulley is provided for redirecting the pulling means such that an operator force is amplifiable
Implementation Method 4
a pull sleeve connected to the pulling means and slidable along the outer tube
Implementation Method 5
at least one elongated channel is arranged at the outer side of the outer tube and extends parallel to the longitudinal axis of said outer tube, wherein at least one portion of the pulling means is guided within the channel
Data Source
AI summary
A telescopic hand tool, in particular a telescopic pruner. The telescopic hand tool comprises an outer tube, at least one intermediate tube slidable within the outer tube and an inner tube slidable within the intermediate tube. At least one tool head is connected or connectable to the front end of the inner tube. A back handle is detachably arranged at the back end of the outer tube. A pulling means is arranged substantially inside the tubes, wherein one end of the pulling means is connected to the back handle, while another end of the pulling means is connected to a fixing point at the front end of the outer tube. A number of deflection pulleys is arranged at the back ends of the tubes and at the front ends of the outer tube and intermediate tube, wherein the deflection pulleys are provided for redirecting the pulling means.