Content

I. Limitations of current method

Limitations of current method

1.1 Description of current method.1.2 Hazards.1.3 Limitation.

1.1 Description of current method

Wipe small cleaning cloth across the surface of the blackboard.

1.2 Hazards

Chalk dust

Formula: CaCO3

Physical attributes: non-combustible, odorless, white powder

1.2 Hazards

Effects on animals:

Causes moderate to severe irritation in contact with tissues

1.2 Hazards

Effects on human

Eyes nose Mucous membrane Respiratory system

1.2 Hazards

Sneeze Inflamation Dry skin

1.2 Hazards

With a near distance like this, cleaner has a high risk of falling ill with the forementioned diseases

1.3 Limitations

After

Before

Content

I. Limitations of current method

II. Solution

II. Solution

2.1 Theory To solve these problems

2.2 Concept

2.3 Limitations and possible modifications

2.1 Theory To solve these problems

Allow the cleaner to stay away from the board’s proximity, effectively reduce the risks from chalk dust

Increase the cleaning surface to reduce the amount of time and work required to clean the board

Optimize the quality of cleaning process, removing chalk dust more effectively

2.1 Theory To solve these problems

2.1 Theory To solve these problems

2.1 Theory To solve these problems

Avoid reduce exposure to chalk dust

2.2 Concept

2.2.1 Summary

2.2.2 Components

2.2.3 Working mechanism

• Cleaning the blackboard by moving a large vertical bar across the surface

2.2.1 Summary

2.2.1 Summary

Blackboard cleaning machine

• Stationary parts: vertical cylinder, horizontal cylinder, pipe, upper rail, lower rail

• Moving parts: vertical piston, horizontal piston, wheel, cleaning pad, connecting rod

2.2.2 Components

2.2.3 Working mechanism

• As the vertical piston is pushed/pulled, the pressure in the vertical cylinder will increase/decrease

2.2.1 Working mechanism

• As the vertical piston is pushed/pulled, the pressure in the vertical cylinder will increase/decrease

• The pressure change, combined with the non-compressibility of the liquid inside, leads to the displacement of liquid in the horizontal cylinder, moving the horizontal piston accordingly

2.2.1 Working mechanism

• As the vertical piston is pushed/pulled, the pressure in the vertical cylinder will increase/decrease

• The pressure change, combined with the non-compressibility of the liquid inside, leads to the displacement of liquid in the horizontal cylinder, moving the horizontal piston accordingly

• The cleaning pad, which is hard-connected to the end of the horizontal piston by the connecting rod, sweeps across the board and clean it in one go

2.3 How it solves the problem of the old model

Dust?

Standing aside while operatinghelps avoiding/reducingcontact with chalk dust.

2.3 How it solves the problem of the old model

Time-consuming?

Larger contact surface and straight trajectorydrastically reduce the amount of timerequired to clean the board.

2.3 How it solves the problem of the old model

Visible stains? without the repeated motion,chalk dust is completelyswept away.

2.3 Limitations and possible modifications

Limitations

• The inability to clean a particular area within the surface

2.2.1 Summary

March 25th 2014

Blackboard cleaning machine

2.3 Limitations and possible modifications

2.3 Limitations and possible modifications

Possible modifications

• Vertically: Separate the cleaning bar into multiple adjacent cleaning pad.

• Horizontally: Use a mechanism to make it possible to lift each smaller cleaning pad off the surface.

2.2.1 Summary

March 25th 2014

Blackboard cleaning machine

2.3 Limitations and possible modifications

2.3 Limitations and possible modifications

Limitations

• Your suggestions?

Content

I. Limitations of current method

II. Solution