Dental Instrument Spray Ring Sealing and Height Reduction

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Solution Overview

Problem

Existing dental handpieces face challenges in maintaining a low overall height while ensuring media sealing and reducing the number of individual parts, particularly in delivering a cooling medium like water and air effectively.

Innovation Solution

A dental preparation instrument design featuring a spray ring with an annular groove that separates water and air storage spaces using a partition wall with a prestressed sealing surface, allowing for integral sealing and reduced part count, and incorporating radial fastening and sealing surfaces for secure attachment and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate sealing components are used to seal water and air media, then reliable sealing is achieved, but the number of individual parts increases and overall height increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidnumber of individual parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple sealing functions into a single integrated spray ring component. The spray ring incorporates both the water storage space sealing and air storage space sealing functions, eliminating the need for separate sealing components for each media type. This merging approach maintains reliable sealing while reducing the total number of parts and overall device height.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spray ring serves multiple functions simultaneously: it seals the water storage space, seals the air storage space, and structures the media separation. This multi-functional design eliminates the need for dedicated sealing components for each function, thereby reducing part count while maintaining sealing reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Length of stationary object

If a radial seal design is used for the partition wall, then axial installation space is reduced, but the stress on the partition wall increases and tolerances must be tighter

Engineering Contradiction:
Improveaxial installation spaceVSAvoidstress on partition wall
Core Design Contradiction:
Length of stationary objectVSStress or pressure

Solution Approach 1:

The patent employs an elastic or elastically-plastically deformed partition wall that can accommodate stress through controlled deformation. By selecting appropriate material parameters and deformation characteristics, the design balances the reduced axial space of radial sealing with acceptable stress levels, allowing more generous tolerances compared to rigid radial seal designs.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the spray ring is designed with integral sealing function, then the number of individual parts is reduced and overall height is lowered, but assembly complexity may increase

Engineering Contradiction:
Improvenumber of individual partsVSAvoidassembly ease
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

While the spray ring itself is an integrated component, the patent maintains segmentation in the assembly process by allowing the spray ring to be assembled into the head as a unit. The modular spray ring design with its internal partition wall structure can be manufactured separately and then installed as a complete sealing assembly, simplifying the overall manufacturing process while maintaining the benefits of integration.

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

This design reduces the overall height, minimizes the risk of jamming during assembly, and ensures effective sealing without overstressing the partition wall, facilitating easier assembly and precise pretensioning for reliable operation.

Implementation Method 1

the partition wall extending radially outwards and having a circumferential free end. At the free end of the dividing wall there is a circumferential sealing surface which, when the spray ring is in the installed state, rests under prestress in a sealing manner

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

the dividing wall being elastic or elastic in the installed state - is plastically deformed

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the dividing wall being elastic or elastic in the installed state - is plastically deformed

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP2708204B1Dental preparation instrument with cold medium delivery
Publication Date: 2018.01.31 SIRONA DENTAL SYSTEMS GMBH CORP LEGAL
  • EP2708204B1 patent drawingFigure 1~7
  • EP2708204B1 patent drawingFigure 3~4
  • EP2708204B1 patent drawingFigure 5~6

AI summary

The instrument (1) has a spray ring (11) having a groove (12) that comprises primary opening (15) through which water is supplied, and secondary opening (16) through which air is supplied. The spray ring is made to separate water reservoir space (13) from air storage chamber (14) by circumferentially extending partition wall (21). The partition wall has a circulating free end (22) extending radially outwards. The free end of partition wall has a circumferential sealing surface (23) which rests in the mounted state of spray ring sealingly biased against contact surface (24) of groove.