Friday, March 25, 2011

E-Learning Lesson 2 Task 1 by Tan Siah Wei (19)

The first Picture is a washing machine, which uses a pulley system. It has a small pulley powered by a motor, and is attached to a much larger one by a thick "rubber band", which drives the compartment holding the clothes. I could not open the washing machine but you can find the mechanism on the net.

The second and third picture show a compact mini gate. This gate has four parts, jointed by hinges. It is kind of like a linkage, except that it is not fixed to a place, but mobile. The two pictures show how it is used and how it is linked.

The fourth picture is a bicycle brake. which uses two bell crank linkages. When the brake levers are pulled, the cable, linked to the bell crank linkages, will become taut, pulling the top of the linkages upwards and therefore forcing the other end of the linkages onto the rim of the bicycle's wheel. Imagine a scissors. Your fingers are the string, and when you push your fingers together, you force the other end of the scissors to snap together. This is the same, except that you are not cutting the bicycle wheel, but instead forcing brake pads against it.

The fifth, sixth and seventh picture is of the mechanism in a real labyrinth. There are two knobs on the side, which you turn to adjust the plane of the labyrinth. There are two springs, one on either side of the labyrinth. The springs are attatched to a string, which is wound around the axle, attatched to the knob, once, then it joins to the other spring. This will turn the labyrinth either left or right. For forward and backward, there is a frame attatched to the labyrinth by an axle, unattatched to knob. The whole spring, string and axle mechanism is the same. The axles do not cross. They are either above or below the other.

Lastly, it is a piano seat with a compartment. When you lift up the top of the seat, you can clearly see a fixed linkage, where it prevents the compartment from closing on the person's hand when he/she is using it.

Thank You.

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