# Toggle position of a fourbar slider-crank

In the fourbar mechanism as in the following picture, I have to find the toggle position, the sliding distance and the time ratio.

Here is my understanding/plan to do this:

• The toggle positions ("extreme ends") of the slider (block B) take place at 2 time, when link 3 and "offset" are aligned, and when link 3 and 2 are aligned.
• The sliding distance can be calculated via trigonometry from the above conclusion
• Assume the working cycle is the part where block B moves from left to right, I have to find the working angle of this movement at crank ($$\beta$$), the time ratio would be $$\frac{360-\beta}{\beta}$$.

Am I right in my understanding so far? If not, where do I have it wrong. And then, how do I obtain the value for $$\beta$$

• Does not seem like offset is a link. If it would be then it would set a really strict limit. The two position happes when link 2 and link 3 form a straight line. Situation $O_2$ to $B$ equals to length of link $B + A$ and oppsite $B - A$. Since offset is constant... Oct 29, 2019 at 19:00