What is the cat for?
The jack helps us to raise the car on the side where we need to change a tire. It is a device designed to withstand large loads , providing security to that change process.
The cat was invented in 1250 by the French architect Villard de Honnecourt . Due to the physical principle with which it works, it is correctly called ” hydraulic jack ” or ” mechanical jack “.
The use of the jack stopped for a few centuries, until in the 19th century, in the year 1840, it was used again for the change of carriage wheels . With advances in technology, its design has become more mechanically efficient than its primitive counterparts.
The name of this device varies depending on the country where it is used. In Spain the word is preserved, but in South America, in countries like Peru and Chile, the name “cat” is used.
Its operation begins by placing it under the side of the car, and its support platform is raised , which faces the weight of the vehicle. The lift can be increased by either turning a crank or repeatedly pressing a lever, depending on how the jack comes from the factory. This lifting procedure is done manually . Thanks to the reduction of forces provided by the cat, the human hand does not require investing so much effort.
The affected tire is removed and the new one is fitted. When the change process is finished, the jack is relieved with a valve or screw that is designed by design, which will release the stress to which it had been subjected.
The jack is a great support for changing both front and rear tires, using the same operating principle.
There are two types of cat:
- Manual jack: they are made up of a rack and pinion.
- Hydraulic jacks: it consists of a hydraulic press, which offers a wider possibility of mechanical work, compared to the manual jack.