What Is an Eccentric Press?
An eccentric press is a type of machine tool that uses an eccentric shaft to convert rotational motion into vertical or horizontal motion. Also known as an eccentric-shaft press or a manual press, it is utilized for operations like cutting, drilling, and bending by attaching a die.
The term ‘eccentric’ in this context refers to the eccentric shaft that enables the reciprocating motion of the slide. This eccentricity is located at the position where it connects to the main shafts of the eccentric shafts (spindle).
Interestingly, the term ‘eccentric’ is also used to describe something unusual in action or character, a nod to the unique motion of the eccentric shaft.
Uses of Eccentric Presses
Eccentric presses are primarily used for press fitting and punching metal sheets. For instance, a die is custom-designed to match the stroke and the committal hole, then attached to the press to cut corners of thin steel plates, typically around 0.3 mm thick.
Some models feature a built-in stopper bolt for mid-stroke stopping, while others, often referred to as standard types, include adjustment bolts on both sides for precise control of the stroke height and other adjustments.
Principles of Eccentric Presses
Eccentricity, a mechanical concept often used in steam locomotives, involves converting the rotary motion of an eccentric shaft into a linear reciprocating motion. Eccentric presses operate on a similar principle: by turning a handwheel, the eccentric shaft’s rotary motion is transformed into a vertical stroke, enabling the press to work through a die.
While hand presses link the pressing motion to the raising and lowering of a lever, eccentric presses differentiate themselves by creating a continuous up-and-down motion akin to a piston. This motion, combined with a suitable die, facilitates the efficient cutting and punching of metal sheets.
Typically operated by a handwheel similar to manual sewing machines, eccentric presses are often found in the used equipment auction market. However, some specialized manufacturers also produce and sell large automated eccentric presses.