What is the Crushing Force of a Concrete Crusher?

AI Thread Summary
The discussion centers on determining the crushing force of a concrete crusher, specifically whether the force exerted by the cylinder on each jaw is halved or not. Participants emphasize the importance of Newton's First Law and the principles of levers in understanding the mechanics involved. The user concludes that the crushing force can be calculated using the formula Ft=Fc*sin(θ)*dc/dt, confirming their understanding of the mechanics. There is also mention of patents related to concrete crushing tongs, indicating further resources available on the topic. Overall, the conversation highlights the application of physics principles in calculating crushing forces in concrete crushers.
nofx1981
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Hi guys,
I need to figure out the crushing force of a concrete crusher. Here's a pic to help illustrate:

CrackerQ.jpg


I have 2 questions:
1) Would the crushing force on the concrete be 2*Ft or only Ft
and
2) Would the force exerted by the cylinder on each jaw be Fc/2 or Fc as shown.

Thanks for you help!
 
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Hi, nofx1981. Is this for a school assignment?
 
Think about action and reaction and Newtons First Law.
Also think about the principles of levers.
 
Last edited:
Hi, nofx1981. Is this for a school assignment?

No, this isn't for school. I've finished school a number of years ago.

Think about action and reaction and Newtons First Law.
Also think about the principles of levers.

Yes, I have been thinking of of Newton's 1st law and levers and such

My first thought was that the cylinder would exert only half of it's force on each lever and that the crushing force would be the sum of forces at the tips. But now I'm thinking that isn't right.

This is my new train of thought. So the cylinder exerts a force Fc=P*A at an angle of theta on each lever. So there is a moment about O of Fc*sin(\theta)*dc for each lever. These moments will apply a force at the tip of each lever Ft=Fc*sin(\theta)*dc/dt and this is your crushing force, right? Ft=Fcrush?

It's been a while since I've done this kind of stuff, would really just like some confirmation...

Thanks for the help!
 
This is my new train of thought. So the cylinder exerts a force Fc=P*A at an angle of theta on each lever. So there is a moment about O of Fc*sin()*dc for each lever. These moments will apply a force at the tip of each lever Ft=Fc*sin()*dc/dt and this is your crushing force, right? Ft=Fcrush?

This is correct. Otherwise the concrete block would fly off somewhere.
And you worked it out for yourself!

I note Google lists several patents on concrete crushing tongs.
 
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