Machine press

Manual goldsmith press

Power press with a fixed barrier guard

A machine press, commonly shortened to press, is a machine tool that changes the shape of a workpiece.^[1]

Types

• Pneumatic press
• Knuckle-joint press

Drives

Hydraulic

Main article: Hydraulic press

Servomechanism

A servomechanism press, also known as a servo press or a 'electro press, is a press driven by an AC servo motor. The torque produced is converted to a linear force via a ball screw. Pressure and position are controlled though a load cell and an encoder. The main advantage of a servo press is its low energy consumption; its only 10-20% of other press machines. Another advantage is a quiet and clean work environment.

Arbor press

Main article: Arbor press

Shop press

A simple frame, fabricated from steel, containing a bottle jack or simple hydraulic cylinder. Good for general-purpose work in the auto mechanic shop, machine shop, garage or basement shops, etc. Typically 1 to 30 tons of pressure, depending on size and expense. Classed with engine hoists and engine stands in many tool catalogs.

Forging press

Main article: Forging press

A forging press reforms the work piece into a three dimensional object—not only changing its visible shape but also the internal structure of the material. A stronger part results from this process than if the object was machined.

Press brake

Press brake

Main article: Press brake

A press brake is a special type of machine press that bends sheet metal into shape. A good example of the type of work a press brake can do is the backplate of a computer case. Other examples include brackets, frame pieces and electronic enclosures just to name a few. Some press brakes have CNC controls and can form parts with accuracy to a fraction of a millimetre. Bending forces can exceed 4,000 kilonewtons (900,000 lbf).^{[citation needed]}

Punch press

Main article: Punch press

A punch press is used to form holes.

Quench press

Main article: Quench press

Rolling press

See also: Rolling (metalworking)

A rolling press has a set of rollers used to thin sheet metal. The sheet metal is fed into the rollers, which are turning, and the sheet is pulled through. The space between the rollers is smaller than the starting sheet metal thickness, therefore the metal is made thinner and/or wider.

Screw press

Main article: Screw press

A screw press is also known as a fly press.

Stamping press

Main article: Stamping press

A stamping press is a machine press used to shape or cut metal by deforming it with a die. It generally consists of a press frame, a bolster plate, and a ram.

Others

Another kind of press is a set of plates with a relief, or depth-based design, in them. The metal is placed between the plates, and the plates are pressed up against each other, deforming the metal in the desired fashion. This may be coining or embossing or forming.

Capping presses form caps from rolls of aluminium foil at up to 660 per minute.

Comparison

Comparison of various machine presses

Type of press	Type of frame							Position of frame				Action			Method of actuation								Type of drive				Suspension			Ram		Bed
	Open-back	Gap	Straight-side	Arch	Piller	Solid	Tie rod	Vertical	Horizontal	Inclinable	Inclined	Single	Double	Triple	Crank	Front-to-back crank	Eccentric	Toggle	Screw	Cam	Rack & pinion	Piston	Over direct	Geared, overdrive	Under direct	Geared, underdrive	One-point	Two-point	Four-point	Single	Multiple	Solid	Open	Adjustable
Bench	X	X				X		X		X	X	X			X		X		X		X	X	X				X			X		X	X	X
Open-back inclinable	X	X				X		X		X		X	X		X		X			X		X	X	X			X	X		X	X		X
Gap-frame	X	X				X	X	X	X	X	X	X	X		X	X	X	X				X	X	X			X	X	X	X	X	X	X
Adjustable-bed horn		X				X		X				X			X		X					X	X	X			X	X		X		X	X	X
End-wheel		X				X		X				X				X	X						X	X			X			X		X	X
Arch-frame			X	X		X		X			X	X			X								X	X			X			X			X
Straight-side			X	X		X	X	X	X		X	X	X	X	X	X	X				X	X	X	X	X	X	X	X	X	X	X	X	X
Reducing	X	X	X			X	X	X	X			X			X							X	X	X			X			X			X
Knuckle-lever			X			X	X	X			X	X	X					X					X	X			X	X		X	X	X	X
Toggle-draw			X			X	X	X					X	X	X		X	X						X		X	X	X	X		X		X
Cam-drawing	X	X	X			X	X	X		X			X		X					X			X	X			X				X		X
Two-point single-action		X	X			X	X	X			X	X			X		X							X		X		X		X		X	X
High-production			X			X	X	X			X	X			X		X						X	X			X	X		X			X
Dying machine					X			X				X			X								X		X		X	X		X			X
Transfer		X	X			X	X	X				X			X	X	X	X					X	X				X		X			X
Flat-edge trimming				X		X		X					X							X				X			X			X
Hydraulic		X	X		X		X	X	X	X		X	X	X								X					X	X		X	X	X	X	X
Press brake	X	X				X		X				X			X							X		X				X	X	X		X

History

Historically, metal was shaped by hand using a hammer. Later, larger hammers were constructed to press more metal at once, or to press thicker materials. Often a smith would employ a helper or apprentice to swing the sledgehammer while the smith concentrated on positioning the workpiece. Adding windmill or steam power yielded still larger hammers such as steam hammers. Most modern machine presses use a combination of electric motors and hydraulics to achieve the necessary pressure. Along with the evolution of presses came the evolution of the dies used within them.

Safety

Machine presses can be hazardous, so safety measures must always be taken. Bi-manual controls (controls the use of which requires both hands to be on the buttons to operate) are a very good way to prevent accidents, as are light sensors that keep the machine from working if the operator is in range of the die.

References

1. ^ Press, http://www.merriam-webster.com/dictionary/PRESS, retrieved 2009-11-24. 

External links

• ISGEC presses