Handle Coupling Pressure Cam for Play-Free Tool Attachment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing handle attachment couplings for garden tools suffer from play-related issues, which can lead to operational difficulties and safety concerns, particularly with accidental actuation of the operating button, resulting in the device coming loose and potentially endangering users.
Innovation Solution
Integration of a pressure cam that engages with the device insertion pin, providing tactile play elimination and enhanced safety by ensuring the device remains securely attached, even during unintentional button actuation, through adjustable compressive force and recess design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a form-fitting connection with a detent spring is used for quick attachment, then ease of operation is improved, but play at the joints increases reducing reliability
Solution Approach 1:
An elastic intermediate piece is inserted between the handle and the device to compensate for play at the joints. This intermediary element absorbs the radial play while maintaining the quick-snap attachment mechanism, thus preserving both ease of operation and joint stability.
2Reliability
If a screw-based non-positive connection is used to eliminate play, then joint stability is improved, but ease of operation deteriorates due to time-consuming assembly
Solution Approach 1:
The elastic intermediate piece serves as a mediator that eliminates the need for screw-based connections. It provides play compensation through its elastic properties while maintaining the quick-snap attachment mechanism, achieving joint stability without sacrificing ease of operation.
Solution Approach 2:
The elastic intermediate piece changes the mechanical parameters of the connection by introducing elasticity and compliance. This allows the system to transition from a rigid screw connection to a flexible elastic connection that maintains stability while enabling quick attachment.
3Device complexity
If a single latching tongue mechanism is used for attachment, then device complexity is reduced, but safety deteriorates due to accidental actuation of the operating button
Solution Approach 1:
The device insertion pin is preliminarily secured by the pressure cam before the latching mechanism is fully engaged. This preliminary securing action ensures that even if the operating button is accidentally actuated, the pin remains held in place, preventing accidental detachment while maintaining structural simplicity.
Solution Approach 2:
The pressure cam provides a cushioning holding force on the device insertion pin before and during operation. This beforehand cushioning ensures that the pin is securely held even if the latching mechanism is inadvertently released, thus preventing accidental detachment without complicating the structure.
4Device complexity
If no additional latching devices are provided beyond the latching tongues, then device complexity is minimized, but safety deteriorates as the coupling piece can separate upon accidental button actuation
Solution Approach 1:
The device insertion pin serves multiple functions: it acts as both the insertion element for the latching mechanism and the secured element for the pressure cam. This multi-functionality provides safety against accidental release without requiring additional dedicated latching devices, thus maintaining minimal device complexity.
Solution Approach 2:
The pressure cam acts as an intermediary safety mechanism that works in conjunction with the existing latching tongues. It provides an additional layer of security by holding the device insertion pin, preventing unintentional release without adding complex dedicated latching devices.
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 solution effectively compensates for play, enhancing the safety and stability of the handle attachment coupling, preventing unintentional detachment and ensuring secure operation during use.
Implementation Method 1
at least one pressure cam (15) which, under elastic pretension, engages in a recess (7) in the side face of the device insertion pin (3) and clamps it
Implementation Method 2
a first curved leaf spring (18) which is fixed in the direction of the center of the free end of the guide piece (12) and has a protruding into the guide channel (14) latching element (20)
Data Source
Figure 1~2
Figure 3
Figure 4~9
AI summary
A handle attachment coupling, particularly for household and garden tools, comprising a guide piece (12) pressed into a handle tube end, which has an elongated guide channel (14) for a tool insertion pin (3) having a first end attached to the tool and a second free end, wherein the second end has a locking opening (6), and comprising a locking element (20) which is biased in a first radial direction transverse to the handle axis by a detent spring (18) and is designed to engage in the locking opening of the tool insertion pin, wherein the locking element can be moved radially out of the locking opening by an operating knob in order to release the tool insertion pin (3) for withdrawal from the guide channel, is characterized in thatthat adjacent to the locking opening (6) in the guide channel (14) of the guide piece (12) at least one elastically prestressed pressure cam (7) in the radial direction inwards is arranged, which is designed to exert radial forces at an angle to the first radial direction on a device insertion pin (3) inserted into the guide channel (14).