Syringe Plunger Switch for 3D Printer Fill Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Imaging devices, such as 3D printers, face challenges in accurately determining the completion of a fill or refill operation of print material particles, leading to risks of overfilling or running out of material, which can damage the device and affect performance.

Innovation Solution

A syringe-based system with a plunger and normally open switch is used to determine the completion of a fill/refill operation by moving the plunger from a first to a second position, expelling print material particles and activating a switch to signal the imaging device, ensuring accurate material levels and preventing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a syringe-based system with plunger and switch is used to determine completion of fill operation, then measurement precision of print material particle levels is improved, but device complexity increases

Engineering Contradiction:
Improveprint material particle levelsVSAvoidsyringe-based system with plunger and switch
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a syringe as an intermediary device between the refill source and the imaging device's material reservoir. The syringe includes a plunger that acts as a mediator to control material transfer, and a switch that serves as an intermediary signal transmission mechanism between the syringe position and the imaging device controller, enabling precise determination of fill completion without requiring complex direct measurement systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex electronic or optical measurement systems with a simpler mechanical indicator system. The plunger's physical position within the syringe barrel serves as a mechanical indicator of material level, and the switch converts this mechanical position into an electrical signal, substituting sophisticated sensing mechanisms with straightforward mechanical-eletrical transduction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If plunger is moved from first to second position to expel print material particles, then productivity of fill operation is improved, but reliability of accurate material level determination may worsen due to mechanical wear

Engineering Contradiction:
Improvefill operation speedVSAvoidaccurate material level determination
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements preliminary positioning features within the syringe barrel, such as predetermined stop positions or calibrated markings, that ensure the plunger reaches exact positions for accurate material level determination. This preliminary structural preparation allows the system to achieve reliable measurement results even with repeated mechanical operations, compensating for potential wear through pre-engineered positional references.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If normally open switch is used to signal completion of fill operation, then ease of operation is improved, but loss of information may occur if switch fails to activate

Engineering Contradiction:
Improveautomatic fill completion signalingVSAvoidfill completion status
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The normally open switch provides immediate feedback to the imaging device controller when the plunger reaches the predetermined position, signaling fill completion. This feedback mechanism ensures the controller receives real-time information about the fill status, preventing information loss by continuously monitoring the plunger position and transmitting completion signals without requiring manual intervention or complex communication protocols.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3765298B1Syringes with plungers
Publication Date: 2024.06.05 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3765298B1 patent drawingFigure 1
  • EP3765298B1 patent drawingFigure 2
  • EP3765298B1 patent drawingFigure 3

AI summary

In some examples, an apparatus (100) can include an outer syringe body (102) including a normally open switch (116) and a pushrod (110) and a plunger (106, 206) including a tab (212), where the tab of the plunger is adapted to be in contact with the pushrod when the plunger is moved from a first position (526) into the apparatus to a second position (528) to cause the pushrod to close the normally open switch.