A hydraulic press is a device (see machine press) using a hydraulic cylinder to generate a compressive force. It uses the hydraulic equivalent of a mechanical lever, and was also known as a Bramah press after the inventor, Joseph Bramah, of England. He invented and was issued a patent on this press in 1795. As Bramah (who is also known for his development of the flush toilet) installed toilets, he studied the existing literature on the motion of fluids and put this knowledge into the development of the press
The Main Principle
The hydraulic press depends on Pascal's principle-the pressure throughout a closed system is constant. One part of the system is a piston acting as a pump, with a modest mechanical force acting on a small cross-sectional area; the other part is a piston with a larger area which generates a correspondingly large mechanical force. Only small-diameter tubing (which more easily resists pressure) is needed if the pump is separated from the press cylinder.
Pascal's law: Pressure on a confined fluid is transmitted undiminished and acts with equal force on equal areas and at 90 degrees to the container wall.
A small effort force acts on a small piston. This creates a pressure which is transferred through the hydraulic fluid to a large piston
Hydraulic presses are commonly used for forging, clinching, moulding, blanking, punching, deep drawing, and metal forming operations. With the growth and importance of light-weighting in the aerospace and automotive industry, more applications are present in Thermoplastics, Composites, SMC Sheet Molded Composites, RTM Resin Transfer Molding, GMT Glass Mat Transfer and Carbon Fiber Molding. All of these applications require precise control and repeat-ability.
End users in many cases need to record data of every press stroke to assure parts meet compliance issues. With I-PRESS Connected Enterprise, users can download and store part to part information that includes, press position, tonnage, speeds, temperatures, automation location, in-feed of material, part exit and more.
With the ongoing surge towards light-weight parts for aerospace, automotive appliances and many other industries, Servo Hydraulic and Hydraulic presses have become a key tool for the Thermoplastic Industries. Otherwise known as compression molding presses, control of speed, pressures, position, heating and cooling mould temperatures can be managed with the I-PRESS HYDRO controller for press and automation functions.
In popular culture
In the 900s the diplomat Liutprand of Cremona, when visiting the emperor in the Byzantine Empire, explained that he saw the emperor sitting on a hydraulic throne and that it was "made in such a cunning manner that at one moment it was down on the ground, while at another it rose higher and was seen to be up in the air".
The room featured in Fermat's Room has a design similar to that of a hydraulic press. Boris Artzybasheff also created a drawing of a hydraulic press, in which the press was created out of the shape of a robot. In 2015, the Hydraulic Press Channel, a YouTube channel dedicated to crushing objects with a hydraulic press, was created by Lauri Vuohensilta, a factory owner from Tampere, Finland.