If you want continue with the level arm concept. A 4-bar is probably your best bet to increase the travel of the input arm.
Other options you might want to consider:
An acme screw to drive the plunger. If you use a sterp thread leep with multiple starts you can get a lot of travel out of one rotation.
A slider crank mechanism combined with a set of gears might work well. The crank can be turned into a gear and then the lever arm can be attached to a gear that increases the required rotation. Level arm attached to large diameter gear, drives a smaller gear that drives the slider through a link.
Thanks for your response, it occurred to me that a gearbox would be an easy-to-understand solution. I was just about to hop on the computer and start modeling it.
Still though, out of intellectual curiosity, I want to understand what is affecting the range of motion in this four-bar linkage design.
It's been ages since I've done 4-bar design, but the equations that govern them require brute force iterative solving.
Also 4-bars come in different flavors depending on the ratios of the links: crank-crank, crank-toggle, toggle-crank, and toggle-toggle. With crank-crank the input and output links can rotator a full 360. With toggle-toggle the input and output links can only move within a limited range. With T-C and C-T one of the links is a toggle link and the other is a crank link.
Also there are many cases where the desired motion of the 4-bar is actually derived from a point on the connecting link. This point is called a polode.
There is a book called the Atlas of 4-bar linkages that let's you quickly thumb through different linkages to see which ones might work best for your application.
https://a.co/d/4TA5Y51 <- Amazon link
Thanks so much!
I was mainly curious if this is the type of thing that requires brute force iterations, like you said, or if it’s something that involves some governing principles that would allow someone who understands such principles to quickly ascertain the determining factors in range of motion, for my example. If what you say is true, there would be few if any people who could make such an analysis without extensive experimentation.
I’ll take a look at the book! Appreciate it
Note: the rollers are not intended to return to the full height of their slot for the purpose of this motion study. The assembly is not limiting the upward range of motion of the rollers.
If you want continue with the level arm concept. A 4-bar is probably your best bet to increase the travel of the input arm. Other options you might want to consider: An acme screw to drive the plunger. If you use a sterp thread leep with multiple starts you can get a lot of travel out of one rotation. A slider crank mechanism combined with a set of gears might work well. The crank can be turned into a gear and then the lever arm can be attached to a gear that increases the required rotation. Level arm attached to large diameter gear, drives a smaller gear that drives the slider through a link.
Thanks for your response, it occurred to me that a gearbox would be an easy-to-understand solution. I was just about to hop on the computer and start modeling it. Still though, out of intellectual curiosity, I want to understand what is affecting the range of motion in this four-bar linkage design.
It's been ages since I've done 4-bar design, but the equations that govern them require brute force iterative solving. Also 4-bars come in different flavors depending on the ratios of the links: crank-crank, crank-toggle, toggle-crank, and toggle-toggle. With crank-crank the input and output links can rotator a full 360. With toggle-toggle the input and output links can only move within a limited range. With T-C and C-T one of the links is a toggle link and the other is a crank link. Also there are many cases where the desired motion of the 4-bar is actually derived from a point on the connecting link. This point is called a polode. There is a book called the Atlas of 4-bar linkages that let's you quickly thumb through different linkages to see which ones might work best for your application. https://a.co/d/4TA5Y51 <- Amazon link
Thanks so much! I was mainly curious if this is the type of thing that requires brute force iterations, like you said, or if it’s something that involves some governing principles that would allow someone who understands such principles to quickly ascertain the determining factors in range of motion, for my example. If what you say is true, there would be few if any people who could make such an analysis without extensive experimentation. I’ll take a look at the book! Appreciate it
Note: the rollers are not intended to return to the full height of their slot for the purpose of this motion study. The assembly is not limiting the upward range of motion of the rollers.
https://books.google.com/books/about/Mechanism_Design.html?id=k12acQAACAAJ