Definition of the Screw Press
Definition of the Screw Press
The screw press is a general term for stamping machines that generate the press power inside frames with more than a pair of male and female screws' rotation. It's categorized into two types;
1) producing static stamping pressure driven screws' torque, and
2) using high temporary dynamic forming power with flywheel's revolution energy fixed to the screws.
History of the Screw Press
The printing press machine Gutenberg (Johann Gensfleisch, c1400-68) of Germany invented in 1400s was modified one from a wooden screw type press machine for squeezing grapes and olive oil. This was exactly the root of the screw presses and all press (stamping) machines, stamping inked print boards onto paper with the screw mechanism (the terminology of “press” in printing and publishing industry actually came from the same root). This is the type of machine to apply static pressure (taking time compression).
Some screw press machines to perform hot forging by static pressure are exhibited at some European Museum and is suspected that the machines were used to produce steel doors and window hardware for European castles or churches in medieval times.
The current forging screw press commonly used progressed as it was equipped with flywheel (swinging) that availed to accumulate energy on the upper end of the male screw axes.That manual rotating flywheel was very hard task and eventually the improvement was made to rotate the flywheel all the time with motive power by means of two rotate friction discs on the upper part of the machine. A link lever alternatively contacts the flywheel covered with cowhide right and left. This was the friction driven screw press, or so-called the friction screw press.
Before the World War II (before 1945), the main stream was manual driven type manipulated by an operator. Everything in slide movements of up and downward, and stamping press power adjustment was relied on the operator's skill. After the War, a method was employed in which the link lever was eliminated, and the changes were made to hydraulic or pneumatic cylinder and push button or foot switch by the control with electrical relay, in addition, a method of ram speed control (press energy control) by detecting slide speed with encoder was introduceed. Also, many kinds of driving method have been innovated not only friction clutch but also hydraulic motor type, AC motor type, etc. Since the drive method for flywheel axis by servomotor has been introduced in market, the market demand significantly shifted from friction drive to servomotor drive method based on the superior performance (discussed later), which resulted more than 80% of current products becoming servo type.
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Man Power Screw Press
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Screw press in Musium
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Manual driven type Friction
Screw Pres -
latest of friction screw press