Watch Crystal Removal Tool Using Controlled Pneumatic Pressure

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Solution Overview

Problem

Existing methods for removing watch crystals from sealed cases often result in damage to the crystal or watch mechanism due to sudden pressure release, which can cause deformation of dials, dislodging of hands, or oil leakage from automatic movements.

Innovation Solution

A tool and method that injects pressurized air into the watch case using a piston pump with a pressure gauge and adjustable screws to slowly release the crystal, avoiding sudden pressure changes by using a flexible pipe and shut-off valve to control air pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high pressure (up to 8 bar) is applied to push the crystal out of the casing, then the glass can be removed from its housing, but the pressure accumulated inside the case will be released all at once causing violent air current that risks deforming dials, dislodging hands or damaging automatic movements

Engineering Contradiction:
Improvesafe removal of crystalVSAvoiddamage to watch mechanism
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by creating a controlled environment before the main action. A housing is placed over the watch case to contain the pressurized air, and the crown is removed beforehand to allow pressure equalization. This preliminary setup prevents the harmful sudden pressure release while enabling effective crystal removal.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a housing as an intermediary element between the pressurized air source and the watch mechanism. This housing contains the pressurized air and provides a controlled environment, acting as a mediator that enables crystal removal without directly exposing the sensitive watch mechanism to high pressure and sudden pressure releases.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a pump external to the casing is used to increase air pressure inside the case, then the glass can be pushed out of its housing, but complex and potentially expensive equipment is required

Engineering Contradiction:
Improvecrystal removal capabilityVSAvoidequipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies self-service by using the watch's own crown opening and internal space to contain and generate the necessary pressure. The existing crown hole serves dual purposes: as an access point for pressure application and as an pressure release valve. This eliminates the need for external pumps and complex equipment, using the watch's own features to accomplish the removal.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If traditional tools like split elastic rings or spring-mounted jaws are used to remove the crystal, then the crystal can be gripped and removed, but damage such as crumbling of the edge of the glass or damage to the casing is risked

Engineering Contradiction:
Improvecrystal removalVSAvoiddamage to crystal or casing
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies pneumatics by using pressurized air to remove the crystal instead of mechanical gripping tools. The pressurized air pushes the crystal out uniformly from the inside, eliminating the need for mechanical contact with the crystal edges. This pneumatic approach avoids the crushing and crumbling problems associated with mechanical tools while effectively removing the crystal.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

Enables safe and controlled removal of watch crystals without causing damage to the watch mechanism, ensuring no deformation of dials, loosening of hands, or oil leakage from automatic movements.

Implementation Method 1

Another type of solution is based on the principle of increasing the air pressure prevailing inside the case to a value such that the glass can come out of its housing

Methodology Applied
Scientific EffectPressure increase: Pressure Increase

Implementation Method 2

a suction cup is pressed on the crystal and attached to it by creating an underpressure in the suction cup

Methodology Applied
Scientific EffectUnderpressure: Pressure Drop

Data Source

PatentEP3835888B1Tool and method for removing a watch glass
Publication Date: 2022.07.13 MONTRES RADO
  • EP3835888B1 patent drawingFigure 1
  • EP3835888B1 patent drawingFigure 2~3A
  • EP3835888B1 patent drawingFigure 3B~3C

AI summary

The present invention relates to a tool (1) for removing a crystal (22) mounted in a watch case initially sealed (2) by elastic engagement in a bezel housing forming a crystal notch, comprising: - a first mounting (3) intended to be positioned on the top of the case with a stop against the external face of the bezel, opposite the crystal (22), having essentially the shape of a ring with a square section with a cylindrical recess (30) suitable for containing the crystal (22) once removed from the bezel; - a second mounting (4) provided with a thread enabling it to be screwed onto the case (2) in place of a watch case back cover, and provided in its center with a through hole (18) to allow the passage of compressed air inside the case (2); and - a third mounting (5) having the form of a solid cylinder intended to be inserted inside the first mounting (3) until it touches the glass (22).