Rack and Pinion Height Adjustment with Automatic Locking

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Solution Overview

Problem

Conventional material collecting equipment, such as lawn sweepers and lawn movers, face issues with inadvertent height adjustment during operation, compromising safety and efficiency due to lack of effective locking mechanisms for height adjustment.

Innovation Solution

A material collection equipment with a height adjustment mechanism featuring a sliding path, rack gear, pinion gear, and a locking arrangement using a clutch and blocking unit that allows safe working height fixation during operation and adjustment only in a parked state, along with marking indicators for easy operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a height adjustment mechanism is provided in conventional material collecting equipment, then the equipment can be adjusted to suit various surface or application requirements, but the mechanism is susceptible to inadvertent adjustment during operation which compromises safety and efficiency

Engineering Contradiction:
Improveheight adjustabilityVSAvoidsafety during operation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The height adjustment mechanism transitions from a static locked position to a dynamic adjustable position through the clutch mechanism. The clutch engages to lock the height during operation and disengages to allow adjustment when parked, making the system dynamically adaptable to different operational states.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The height adjustment mechanism is self-regulating through the clutch and blocking unit system. When the equipment is in operation, the clutch automatically engages to prevent inadvertent adjustment. When parked, the blocking unit retracts to allow adjustment, eliminating the need for manual intervention to switch between locked and unlocked states.

Inventive Principle:
Principle #25Self-service

2Reliability

If a locking arrangement is added to prevent inadvertent height adjustment, then safety during operation is improved, but the complexity of the height adjustment mechanism increases

Engineering Contradiction:
Improvesafety during operationVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking arrangement is merged with the height adjustment mechanism itself. The clutch and blocking unit are integrated into the existing adjustment structure, so the locking function is achieved without adding a separate independent locking system, thereby minimizing additional complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking mechanism is self-actuating through the clutch and blocking unit system. The clutch automatically engages or disengages based on operational state, and the blocking unit moves accordingly, eliminating the need for separate control systems or additional manual operations to activate the locking function.

Inventive Principle:
Principle #25Self-service

3Reliability

If a clutch and blocking unit locking arrangement is implemented, then inadvertent adjustment is prevented during operation, but the ease of operation for height adjustment may be reduced

Engineering Contradiction:
Improveprevention of inadvertent adjustmentVSAvoidease of height adjustment
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The clutch mechanism provides dynamic control where the locking state automatically changes based on operational conditions. During operation, the clutch engages to prevent adjustment. When parked, the clutch disengages and the blocking unit retracts, allowing easy adjustment without requiring additional manual steps to disengage locks.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system automatically manages the locked/unlocked state through the clutch and blocking unit. The user simply needs to operate the height adjustment mechanism when parked, and the system self-manages the locking and unlocking states based on whether the equipment is in operation or parked, reducing the operational burden on the user.

Inventive Principle:
Principle #25Self-service

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 safe, convenient, and reliable height adjustment, enhancing user safety and operational efficiency by preventing inadvertent changes during use and allowing easy adjustment for different surfaces or grass levels.

Implementation Method 1

the sliding path includes a rack gear, and the adjustment knob has a pinion gear in rotational engagement with the rack gear

Methodology Applied
Scientific EffectRack and pinion mechanism: Rack and Pinion

Implementation Method 2

a locking arrangement to lock sliding motion of the adjustment knob within the sliding path. The locking arrangement includes a clutch operatively coupled to the adjustment knob, and a blocking unit operatively coupled to the sliding path

Methodology Applied
Scientific EffectMechanical locking: Mechanical Fastener

Data Source

PatentEP3768896B1Height adjustment of mobile garden tools
Publication Date: 2022.01.12 HUSQVARNA AB
  • EP3768896B1 patent drawingFigure 1
  • EP3768896B1 patent drawingFigure 2
  • EP3768896B1 patent drawingFigure 3A~3B

AI summary

A material collection equipment (100) includes an implement (112) compartment (106) which includes a first side wall (108), a second side wall (110) opposite with respect to the first side wall (108). The material collection equipment (100) further includes a height adjustment mechanism (120) to adjust a working height (h) of the material collection equipment (100) relative to a ground surface (A-A'). The height adjustment mechanism (120) includes a sliding path (122) defined on an outer surface of the implement compartment (106). The height adjustment mechanism (120) includes a bar (124) coupled to the first side wall (108) and the second side wall (110). Further, the height adjustment mechanism (120) includes an adjustment knob (126) coupled to the bar (124). The material collection equipment (100) is characterized in that the sliding path (122) includes a rack gear (302), and the adjustment knob (126) has a pinion gear (304) in rotational engagement with the rack gear (302). Further, the material collection equipment (100) includes a locking arrangement (306) to lock sliding motion of the adjustment knob (126) within the sliding path (122).