Ring Fastening Element for Door Handle Retention
Solution Overview
Problem
Handle sets for doors and windows face challenges in securely fastening and maintaining heavy handles due to increased play between the handle guide and bearing point, requiring special solutions that deviate from standard quality, and existing solutions fail to easily dismantle or securely hold handles in position.
Innovation Solution
A handle set with a ring-shaped fastening element that engages behind the handle, featuring radially projecting retaining fingers and a U-shaped cross-section for secure anchoring and rotational movement transmission, combined with a torsion spring for additional support, allowing easy assembly and maintenance-free operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a heavy handle is used for design reasons, then the aesthetic appearance is improved, but the handle cannot be securely held in its initial position or brought back into this position by the handle retaining spring
Solution Approach 1:
The fastening element is divided into multiple retaining fingers (at least two) that are distributed around the circumference, with each finger independently engaging with the handle. This segmentation allows the heavy handle to be securely held through multiple contact points while maintaining the ability to be released by a single pulling action on the handle.
Solution Approach 2:
The fastening element is made of elastic material (spring steel) and is designed to be deflectable. When the handle is pulled, the retaining fingers deflect radially outward to release the handle, then automatically return to their initial position to re-engage the handle. This elastic parameter change enables reliable positioning of heavy handles without requiring additional springs or complex mechanisms.
2Force
If special bearings and plastics are used to meet high force absorption requirements, then the force absorption capability is improved, but the solution deviates from standard quality and increases complexity
Solution Approach 1:
The fastening element serves multiple functions simultaneously: it absorbs radial forces through its elastic deformation, absorbs axial forces through the retaining fingers engaging with the handle, and provides rotational support. This multi-functionality eliminates the need for separate specialized bearings and plastics, maintaining standard quality while achieving high force absorption capability.
Solution Approach 2:
The elastic material of the fastening element allows it to deform under force and return to its original shape, providing cushioning and absorption capabilities. This material parameter change enables the standard-quality fastening element to handle high radial and axial forces without requiring complex specialized bearings.
3Reliability
If the handle is securely fastened with a complex fastening mechanism, then the handling security is improved, but the ease of dismantling is reduced
Solution Approach 1:
The retaining fingers are designed to be dynamically responsive - they automatically engage with the handle when inserted and automatically release when pulled. The elastic nature of the fastening element allows it to flex outward when force is applied, enabling easy removal without tools, while maintaining secure engagement during normal use.
Solution Approach 2:
The fastening mechanism is self-acting - the retaining fingers automatically engage with the handle's circumferential groove without requiring additional fastening operations. The elastic material self-returns to its initial position after deformation, automatically re-engaging the handle after removal and installation cycles without requiring manual intervention or complex dismantling procedures.
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 provides a secure, maintenance-free handle fastening system that can handle heavy loads without altering the lock, reduces costs by using standard components, and extends service life through lubrication and protection against contamination, while allowing easy handle replacement and assembly without tools.
Implementation Method 1
the fastening element has at least one retaining finger which projects radially inwards and which engages in a receiving opening, in particular in a circumferential groove on the handle
Implementation Method 2
the U-shaped cross-section serves as a receiving space for a torsion spring, which supplements and supports the spring of the lock for holding the handle
Implementation Method 3
The basic construction is modular and can be used for fire and noise protection applications by adding a steel cover rosette, while retaining the decorative outer cover
Data Source
Figure 1
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AI summary
The set has a handle (12) supported at a base plate (14) and comprising a bearing pin (20). The base plate is provided with a handle bearing (18) that supports the handle in axial direction and in radial direction. The base plate comprises a ring shaped fastening element (34) that engages the handle in sections. The fastening element comprises holding fingers that project radially inwards an engaged in a receiving opening i.e. circumferential groove (48), and has a bifurcated free end, where the fastening element is made of metal.