Mechanical engineering perhaps has the oldest known inventions and patents. In fact, the word engineering is derived from a mechanical component. Mechanical engineering is a field that was conceived from natural laws of physics, where one engineers or manipulates these laws to his/her advantage. Mechanical patents non exhaustively and generally encompass utility tools invented constituting force, motion, mass, etc. It specifically encompasses all mechanical devices, contraption and interactions resulting in utilitarian instruments and apparatus, and where such interactions produce a action-reaction component that depends on the mechanism and nature of interaction. Further, all manufacturing processes, for example, metal working and treatment, printing, textile manufacturing, etc, are regarded under mechanical patents. Automobiles fall under mechanical patenting category, although one cannot be sure where a time travel machine, if invented, will be categorized. Of course, most mechanical engineering fields involve extensive use of computational and mathematical tools, physical laws and equations, but these fall under a different patenting category altogether.

Mechanical inventions have no constraints as they range from a simple yet effective patented invention of a four year old from Texas for An aid for grasping round knobs to researched and focused inventions in all areas of mechanical expertise. Few of the well known companies that have a good mechanical patent portfolio include Canon Kabushiki Kaisha with 6798 US patents, General Electric company with 6649 US patents, Xerox Corporation with 2736 US patents and Ford Motor Company, which currently has about 2671 US patents. Some inspiring patented mechanical inventions include legacy devices such as typewriters, Xerox machines to modern inventions such as biomorphic robots, everting heart valves, etc.

The United States Patent and Trademark Office currently specifies 248 major classes for mechanical patents. Each class is given a class definition, and inventions are further categorized into subclasses, where each patent application may be classified under more than one class/subclass. As exemplifications few class definitions are provided here. One class definition encompasses apparatuses that produce compressive force, another encompasses apparatuses for transferring fluent materials through enclosed structures, yet another encompasses apparatuses for supplying air to, circulating air in and removing air from enclosed spaces.Then there are subclasses defined for each mechanical unit or component of a larger entity. This demonstrates the extent of classification accomplished by the USPTO.

The future of mechanical innovations is considerably bright, not just in the automobile industry but also in sectors like robotics, printing technology, and many more. Mechanics is used to manufacture machines; it is used by the machines, and for enabling the machines. Mechanical innovations gifted us the ease and flexibility of transportation in all forms including inland, air and sea; will aid us in rebuilding the WTC using huge construction equipment and intricate structural frameworks, to relish life with little things like toys, amusement rides, etc.