Mower Blade Device With Preloaded Tension Spring Guide Bushing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing mower blade devices experience high wear and maintenance costs due to the mechanical stress and contamination between the upper and lower cutting blades, leading to reduced service life and increased operational expenses.

Innovation Solution

A mower blade device with a double knife cutting system featuring a preloaded tension spring in a guide bushing to evenly distribute contact pressure between the upper and lower cutting knives, along with a one-piece design for the blade elements and a replaceable knife head with an elastic section to reduce mechanical stress and facilitate maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a rigid holding device is used to maintain contact force between cutting blades, then cutting performance is improved, but wear on the cutting blades increases due to uneven contact pressure and mechanical stress

Engineering Contradiction:
Improvecutting performanceVSAvoidservice life of cutting blades
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The holding device is designed with a guide bushing that allows controlled movement and yielding in the direction opposite to the contact force. This dynamic capability enables the device to adapt to variations in cutting conditions, maintaining even contact pressure while reducing mechanical stress on the blades, thereby resolving the contradiction between cutting performance and blade service life.

Inventive Principle:
Principle #15Dynamics

2Ease of repair

If the holding device is designed to be easily disassembled for maintenance, then ease of repair is improved, but the structural complexity increases

Engineering Contradiction:
Improveease of cutting blade replacementVSAvoidstructure of holding device
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The holding device is segmented into distinct components including the guide bushing, tension spring, and holding elements. This segmentation allows individual parts to be easily removed or replaced without disassembling the entire device, improving ease of repair while the modular design actually reduces overall structural complexity by allowing standardization of components.

Inventive Principle:
Principle #1Segmentation

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 significantly reduces wear on the cutting blades, extends the service life of the mower blade device, and simplifies maintenance by evenly distributing contact pressure and reducing mechanical stress, while also improving the efficiency of cutting and handling.

Implementation Method 1

a prestressed tension spring (170) is arranged within the guide bushing (160A). The tensile force of the tension spring (170) is designed to cause a contact force of the upper cutting blade (140) on the lower cutting blade (180)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4236669B1Mower blade device
Publication Date: 2024.08.21 WEPFER TECHNICS AG
  • EP4236669B1 patent drawingFigure 1
  • EP4236669B1 patent drawingFigure 2
  • EP4236669B1 patent drawingFigure 3~4

AI summary

The invention relates to a mower knife device (100), comprising a knife bar (110) and a double-knife cutting system, wherein the double-knife cutting system comprises an upper cutting knife (140) and a lower cutting knife (180) which can be moved relative to one another, wherein the upper cutting knife (140) is connected to the knife bar (110) by means of an upper holding device (150) and the lower cutting knife (180) is connected to the knife bar by means of a lower holding device (190), wherein the upper holding device (150) is mounted on the knife bar (110) by means of a guide bush (160A) and a preloaded tension spring (170) is situated inside the guide bush (160A), wherein the tensile force of the tension spring (170) is intended to bring about, via the upper holding device (150), a compression force of the upper cutting knife (140) onto the lower cutting knife (180).