Select the headings from the left column below:

1. Motivation

2. Approach

3. Solution

4. Conclusion

Approach

Controlled Motor with Pull Ring

Before starting the movement, the locking mechanism needs to be disengaged. After this, pulling downwards on the pull ring will stretch the spring, and hence move the sliding bar in the direction of the pull ring. As the sliding bar moves it will turn the gear.

At this outstretched spring position, the locking mechanism is engaged, in order to prevent the spring to pull the sliding bar back to its original position. Disengaging the two locking mechanisms, alternatively, will allow the spring to pull the sliding bar one notch at a time. The teeth spacing on the locking mechanism and their contact site of the sliding bar is double the teeth spacing of the gear. This ensures that when the sliding bar is moving one notch at a time, the gear will be turning exactly one tooth at a time. The gear will be turning until the spring has restored to its original position.

Controlled Motor with Linear Stepper Motors

This design is similar to the Pull Ring design. The difference is that the pull ring mechanism has been replaced by two linear stepper motors. The linear stepper motors will pull down the sliding bar and stretch the spring. Everything else functions in the same manner as for the pull ring. This particular design eliminates the need for a human to pull as well as any errors connected to this action. Such errors may include pulling the ring too far, which might break the spring or pulling on an angle which might weaken the connections between the spring and the sliding bar. .

ENSC 494 Summer 2003 - George Kwei - Mirela Cunjalo - Gary Lu