How to increase force or length this unit?

[NEPA]

Please find attached a JPEG file ---- that when the lever is pulled down, there will be two actions: 1) the inner tube to the right will move no more than 1 inch and then the remaining effort to pull the lever down to it's "home" position will compress the springs creating the compression force to hold the unit in place between two walls. Apparently, there are limitations to the size of the spring inside the tube and the ability to increase the toggle links / mechanisms, thus the reason for only a 1 inch "throw" (to me that means it will only be able to expand the 1 inch "gap" between the wall and the rubber pad PRIOR to engaging the lever.

I would like to ask [anyone] that understands springs / scissor action, etc. to comment / assist on the following:

1) If the spring mechanism, which is now housed in the inner tube of 1 1/2 inch Dia., is moved to the left inside the outer tube of 1 3/4 inch, would that allow a somewhat larger diameter spring to increase the amount of generated force? Small change?

2) If somewhere between the toggle link and the first spring adapter, I tried to insert a series of scissor actions (not sure what this is actually called), so that when the lever is pulled down, not only is the push rod moved outward, but the scissors would travel thru a roller (or some stationary point) so that the scissors would be "squeezed" and flattened out thus causing and additional length of inner tube to move outward?

3) If you have any other suggestions on how I can increase force or increase length of the tube outward without changing the current linkage config. (trying to keep effort ~ 30 #'s), please let me know and thank you very much!

Since the scissors at their relaxed state has available vertical space, I could use that when the scissors are flattened out...

Would you mind commenting on this? Thank you in advance for any assistance, Charlie

 

[Achy47]

Dear Charlie,

Thank you for sharing your design and seeking input from the scientific community. I am a scientist with expertise in mechanical engineering and I would be happy to offer my thoughts on your questions.

1) Moving the spring mechanism to the left inside the outer tube may allow for a slightly larger diameter spring to be used. However, the increase in force generated would likely be minimal. The force generated by a spring is directly proportional to its stiffness and displacement. So, even with a larger diameter spring, the overall displacement may still be limited by the 1 inch "throw" you mentioned. Additionally, the change in diameter may also affect the overall stiffness of the spring, potentially reducing the force generated.

2) Adding a series of scissor actions in between the toggle link and the first spring adapter may increase the overall displacement and force generated. This is because the scissor actions would allow for additional length of the inner tube to move outward, as you mentioned. However, this would also add complexity to the design and may require more force to operate the lever. It would be important to carefully consider the trade-offs between increased force and added complexity in your design.

3) One potential way to increase the force or displacement without changing the current linkage configuration could be to use a different type of spring, such as a tension spring instead of a compression spring. Tension springs can generate a greater force and potentially allow for a longer displacement compared to compression springs. However, this would also require a redesign of the linkage to accommodate the different type of spring.

In regards to using the available vertical space in the relaxed state of the scissors, it could potentially be used to increase the displacement or force generated. However, it would be important to carefully consider the mechanics of the scissors and how they would interact with the rest of the design.

Overall, my suggestion would be to carefully analyze the mechanics and forces involved in your design and consider all potential trade-offs before making any changes. It may also be helpful to consult with a mechanical engineer or other experts in this field for further input and assistance.

Best of luck with your design and feel free to reach out if you have any further questions.