ALAN LI

 

Objective: To design the extension mechanism for an extendable clothes hanger, maximizing speed and ease of use. 

 

Criteria and Constraints:

• Must shorten when button is pressed and elongate depending on the allowable distance between the arm and the clothing when released

• Must be able to fit within the standard dimensions of a clothes hanger

• Must be able to accommodate the majority of clothing sizes

• Ease of use

• Cost of mechanism

• Size and weight

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Iterative Process:

 

Several candidate mechanisms were considered, including scissor, spring, gear and pneumatic mechanisms.

 

Using a pugh chart, the solutions were scored, and the scissor and pneumatic mechanisms were eliminated, and the spring and gear were left. In the second iteration of the pugh chart, there was no winner between the spinrg and the gear, and the decision was to combine them. 

 

The selected solution consisted of a spring attached to a flexible, U-shaped handle which can be compressed. Compressing the handle will retract a rack which is aligned with a compound gear, in turn retracting the arm of the hanger. The compound gear is key to retracting the arms fully, as they multiply the rotation caused by compressing the handle.