Split Blade Housing Sleeve Assembly for Stable Rotary Knife Clearance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional power operated rotary knives face challenges in maintaining optimal operating clearance and stability of the blade support section during cutting operations, particularly when encountering large cutting reaction forces, leading to operator-adjusted diameter changes that can result in suboptimal performance or component wear.

Innovation Solution

A blade housing assembly with a split ring blade housing and an expansion sleeve assembly, featuring a split lock sleeve that maintains the blade housing in a stable position using elasticity, eliminating the need for constant external pressure, and a threaded fastener for securement, ensuring preset operating clearance and resistance to cutting reaction forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed blade housing design is used, then manufacturing simplicity is maintained, but the housing cannot adapt to different blade lengths and creates excessive clearance with longer blades

Engineering Contradiction:
Improveadaptability to different blade lengthsVSAvoidhousing structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The blade housing is divided into a stationary housing portion and a movable expansion sleeve portion. The expansion sleeve can slide within the stationary housing to adjust the effective length of the blade housing, allowing adaptation to different blade lengths while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The expansion sleeve is designed to be movable relative to the stationary housing portion, allowing dynamic adjustment of the housing length. This dynamic component enables the housing to adapt to various blade lengths and reduce clearance issues without requiring a completely complex redesign.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the blade housing is made longer to accommodate longer blades, then blade length adaptability improves, but clearance between the housing and blade increases with shorter blades

Engineering Contradiction:
Improvecompatibility with various blade lengthsVSAvoidexcessive clearance causing vibration and instability
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The expansion sleeve can be positioned at different locations along the stationary housing portion to dynamically adjust the effective length of the blade housing. This allows the housing to closely fit shorter blades when the sleeve is retracted and accommodate longer blades when the sleeve is extended, minimizing clearance and preventing vibration across all blade lengths.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The effective length parameter of the blade housing is made variable through the movable expansion sleeve. By changing the position of the expansion sleeve, the housing length parameter can be optimized for each specific blade length, eliminating excessive clearance and its harmful effects while maintaining adaptability.

Inventive Principle:
Principle #35Parameter changes

3Ease of repair

If a non-adjustable blade housing is used, then structural simplicity is maintained, but blade changes require complete housing replacement increasing maintenance time

Engineering Contradiction:
Improveblade change efficiencyVSAvoidtime to replace blade housing
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The blade housing is segmented into a stationary portion and a movable expansion sleeve portion that can be independently adjusted. This segmentation allows the blade and expansion sleeve to be removed and replaced without replacing the entire housing structure, significantly reducing maintenance time and improving blade change efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The movable expansion sleeve design allows for quick adjustment and removal mechanisms. When blade changes are needed, only the blade and expansion sleeve need to be removed from the stationary housing portion, rather than replacing the entire housing, thereby reducing downtime and improving ease of repair.

Inventive Principle:
Principle #15Dynamics

4Stability of the object's composition

If the blade housing is designed for tight clearance, then stability with short blades is improved, but vibration and instability occur with longer blades

Engineering Contradiction:
Improvehousing-blade fit stabilityVSAvoidcompatibility across different blade lengths
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The movable expansion sleeve allows the housing length to be dynamically adjusted to match different blade lengths. With shorter blades, the sleeve is retracted to provide tight clearance and stability. With longer blades, the sleeve is extended to maintain the same tight clearance fit, preventing vibration and instability while preserving adaptability across all blade lengths.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4037879B1Split blade housing with expansion sleeve assembly for power operated rotary knife
Publication Date: 2026.05.20 BETTCHER IND INC
  • EP4037879B1 patent drawingFigure 1
  • EP4037879B1 patent drawingFigure 2
  • EP4037879B1 patent drawingFigure 3

AI summary

A blade housing assembly for a power operated rotary knife including a split blade housing and an expansion sleeve assembly. The split blade housing including an annular blade support section and a mounting section extending from the blade support section. The mounting section includes a split extending through the mounting section and includes a first body portion and a second body portion on opposite sides of the split, the first body portion including a slot extending axially through the first body portion and movable between blade supporting and blade changing positions. The expansion sleeve assembly extends through the slot and includes a split sleeve changeable between first and second circumferences. The expansion sleeve assembly further including a fastener extends through the split sleeve and, when engaged with the split sleeve, maintains the split sleeve in the first circumference and secures the first body portion in the blade supporting position.