Dental Handpiece Head Venting for Suck Back Without Torque Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dental handpieces suffer from suck back phenomena due to rotor inertia after air supply cessation, which leads to a decrease in torque of the cutting tool.
Innovation Solution
The dental handpiece incorporates air supply ports, diffuser portions, and air-retaining portions to manage airflow direction and retention, preventing suck back while maintaining torque by reducing inertial rotation momentum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air is accumulated in the head to prevent suck back, then suck back is prevented, but torque of the cutting tool significantly decreases
Solution Approach 1:
The head is divided into multiple functional zones: a first air-retaining portion for maintaining positive pressure to prevent suck back, and a second air-retaining portion for preserving air for rotor rotation. This segmentation allows independent optimization of each zone's function, preventing the torque reduction that occurs when the entire head volume is used for air accumulation.
Solution Approach 2:
The harmful inertial rotation of the rotor after air supply cessation is extracted and utilized beneficially. The patent directs this inertial rotation to drive air from the second air-retaining portion into the air discharge port, converting the harmful effect into a useful function for maintaining positive pressure and preventing suck back without compromising torque.
2Duration of action of moving object
If the rotor rotates by inertia after air supply stops, then the cutting action continues, but the head functions like a pump and sucks saliva and blood
Solution Approach 1:
Air is pre-accumulated in the first air-retaining portion before the rotor stops rotating. This preliminary action creates a positive pressure environment that counteracts the suck back effect generated by inertial rotation, preventing saliva and blood from being drawn into the head while allowing the rotor to continue rotating for cutting action.
3Reliability
If air is discharged from the head after supply stops to prevent negative pressure, then suck back is prevented, but torque decreases
Solution Approach 1:
Air is preliminarily accumulated in the second air-retaining portion during the operation phase. When air supply stops, this pre-stored air is then utilized to maintain positive pressure during rotor inertial rotation, preventing suck back without requiring additional air discharge that would reduce torque.
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
Prevents suck back and maintains cutting tool torque by effectively managing airflow and pressure balance within the handpiece.
Implementation Method 1
at least one air supply port configured to supply the air supplied from the supply tube to the inside so as to rotate the at least one rotor in a specific direction
Implementation Method 2
at least one diffuser portion configured to change a flow direction of a part of the air supplied from the at least one air supply port so as to direct the part of the air toward the at least one rotor in a direction opposite to the specific direction
Implementation Method 3
at least one air-retaining portion configured to communicate with the air discharge port and retain the part of the air supplied from the at least one air supply port
Implementation Method 4
there occurs a phenomenon in which even after the supply of the air to the rotor is stopped, the rotor rotates by inertia, whereby the inside of the head functions like a pump to suck saliva, blood or the like of a patient
Data Source
AI summary
A dental handpiece includes a body and a head. The body includes a supply tube configured to supply air to the head. The head includes a housing, a rotor, and a holding portion configured to rotate a cutting tool with rotation of the rotor. The housing includes: an air supply port configured to supply the air supplied from the supply tube to the inside; an air discharge port disposed on a side closer to a tip end of the cutting tool than the air supply port and configured to discharge the air from the inside; a diffuser portion configured to change a flow direction of a part of the air supplied from the air supply port so as to direct the part of the air toward the rotor; and an air-retaining portion configured to retain the part of the air supplied from the air supply port.