If you have a lever in your home, you may also have a “speaking tube,” which was a hole in the wall at the top of the stairs that you could talk to your incoming guests through.

The arrangement of the class 3 lever can be the most difficult to visualize. The fulcrum is still at one end of the lever, but the effort is now in the middle, with the load at the opposite end.

Supremely Smooth: The quad bar linkage and slider crank mechanism at the heart of the action sets a new standard for out-of-the-box lever-action smoothness.

Lever mechanisms can be joined together to form linkages. Simple linkages can be used to change the direction of motion and the amount of force.

The four bar linkage is a type of mechanical linkage that is used in many different devices. A few examples are: locking pliers, bicycles, oil well pumps, loaders, internal combustion engines, comp… ...

Save guides, add subjects and pick up where you left off with your BBC account. A lever is a simple mechanism that uses a bar to pivot around a fixed point called a fulcrum. Levers can be joined ...