When we think of machines, great inventions such as cars, trains or industrial robots probably come to mind.
However, many of the most important machines we use on a daily basis are much simpler. We call these simple machines, and they have been with us since the dawn of civilization, helping to make tasks easier and more efficient.
Although the term "simple machine" may sound technical, the truth is that we use these mechanisms all the time, often without realizing it.
In this article, I will show you how simple machines are present in things as common as a kitchen knife or a ramp.
Let's look at 10 everyday examples of simple machines that you probably already know, but perhaps hadn't identified as such.
1. Bottle opener: a lever in your hands
Let's start with something as simple as a bottle opener. Have you ever stopped to think about how this little object works? Although it seems trivial, this device is an excellent example of a lever in action.
When using a bottle opener, the serrated part hooks under the cap, and when you pull up, the cap pops off with very little effort. This is because the opener acts as a first-class lever, where the fulcrum (the fulcrum point) is between the cap and the force you apply. This allows you to open the bottle without having to apply a great deal of force.
You can find these types of levers everywhere, from nail pullers to simple seesaws in parks.
2. Conveyor belt in supermarkets: a moving inclined plane
You've probably seen those conveyor belts at the checkout in the supermarket, where you place your products so they reach the cashier. Although it may seem like a modern system, the idea behind this mechanism is very old: it's a moving inclined plane.
An inclined plane is a surface that is tilted rather than vertical, and makes it easier to move heavy objects with less effort. The conveyor belt, being tilted almost imperceptibly, makes the products move smoothly forward without the need to constantly push or lift them.
This principle is the same as that used in ramps for people with reduced mobility or in access ramps to garages. Instead of lifting a heavy object in one fell swoop, an inclined plane allows it to be moved over a greater distance, which distributes the effort more evenly.
3. Pulley Lift: Lifting with ease
The next example is a classic one that we often overlook: elevators. Although many elevators today are powered by complex electric motors, the basic principle behind them is a pulley system.
A pulley is a wheel that allows you to change the direction of a force. In the case of an elevator, when the motor pulls on the rope holding the cabin, the pulleys distribute the effort, allowing large loads (in this case, people and objects) to be lifted and lowered with relatively little force. If you've ever had to use a pulley system to raise a flag or lift a load, you'll have noticed how much easier it is to do.
By combining fixed and movable pulleys, a system called a hoist is created, which further reduces the amount of force that must be applied to lift large weights.
4. The garden shovel: cutting the ground like a wedge
The garden pick or spade is one of the simplest and most useful tools out there. When you're digging in the ground, the spade isn't just used as an object to move the soil from one place to another, you're actually using a wedge.
The sharp end of the shovel digs into the ground and splits the soil, making it easier for you to move it. Essentially, the shovel transforms the downward force you apply into a sideways force, splitting the soil. This same principle applies to cutting tools such as axes, knives, and chisels.
The next time you use a shovel to dig a hole in your garden or do some digging, remember that you are taking advantage of one of the oldest principles of mechanics.
5. Pruning shears: a sharp lever
The pruning shears we use in gardening are another excellent example of how simple machines make work easier. This tool combines two simple machines: a wedge and a lever.
The sharp blades of the shears act like wedges, cutting through branches with precision. But the real trick of the pruning shears is in the long handles, which work like a lever. The longer the handles, the more force you can effortlessly apply. This way, you can cut through thick branches with little effort, something that would be difficult if you tried to do it with your bare hands.
6. Wheelchair: the power of the wheel and axle
The wheelchair is another clear example of a simple machine that has changed the lives of millions of people. The wheel and axle is one of the most important inventions in history, and its principle is applied to many everyday situations.
On a wheelchair, wheels help reduce friction between the floor and the chair, making movement easier. Without wheels, moving a chair with a person sitting on it would be a strenuous task. When the wheel turns, the central axis also moves, transmitting the applied force along the surface, allowing the chair to move with little effort.
This same principle is what allows bicycles, cars and wheelbarrows to work.
7. Door handles or knobs: turn with a lever
You probably open doors several times a day, and you do so automatically, without thinking about the mechanism behind the door handles or latches. But what you're actually using is a lever.
When you turn a door handle, you are applying a small force to the end of the lever. This force is transmitted to the internal mechanism, which releases the latch and allows the door to swing open. Without the handle, opening a door would be much more difficult, as you would have to apply force directly to the latch.
These types of levers are found in many everyday mechanisms, from gear shifts in cars to light switches.
8. Hydraulic jack: lifting a vehicle with a screw
If you've ever had to change a car tire, you've probably used a jack. This tool is a perfect example of how a screw can multiply the applied force and allow you to lift large weights.
When you turn the jack handle, an internal screw moves, causing the jack to rise, lifting the car. Although the car may seem too heavy to lift manually, the screw design distributes the force efficiently, making it possible to raise the vehicle with very little effort.
This principle is applied in many other tools, such as presses or load lifting systems.
9. The kitchen knife: a wedge for precise cutting
The kitchen knife is a tool that we all use on a daily basis. When you cut an apple or a piece of meat, you probably don't think about the fact that you're using a simple machine, but you are. The knife is, in essence, a wedge.
The knife blade splits the material you're cutting into two, allowing the force you apply with your hand to be concentrated on the edge of the blade. This makes it much easier to cut food than it would be if you tried to do it with a dull blade or with your hands.
Wedges are used not only in the kitchen, but also in other areas such as construction and carpentry, where cutting tools are essential for accurately splitting materials.
10. Roller blinds: a hidden pulley system
Finally, an example you probably haven't considered is roller blinds, which are used to raise or lower the blinds in a room. Although it may not seem like it at first glance, this mechanism uses a combination of pulleys and wheels.
When you pull the curtain cord, you are using a pulley system that changes the direction of the force, making it easier for you to raise or lower the curtain without having to apply much force. This same principle applies to crane systems, elevators and other lifting mechanisms.