Basic Press Designs
Press -
A machine having a stationary bed or anvil and a slide (ram or hammer) which has reciprocating motion toward and away from the bed surface and at right angles to the bed surface, the slide being guided in the frame of the machine to give a definite path of motion.
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Mechanical Press -
A press whose slide or ram is operated by a crank, eccentric cam, toggle links or other mechanical means, as contrasted to fluid or other means.
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Crank Press -
Mechanical press slide actuated by a crankshaft.
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Double Action Press -
A mechanical press having two independent parallel movements of two mechanical press slides. One slide is operated by a crankshaft - the outer or blankholder slide which dwells during the drawing process is usually operated by a toggle mechanism or cams.
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Double Crank Press -
A mechanical single action press in which the slide is operated by two cranks and connections. There are two basic classifications for mechanical double crank presses:
1. Straightside press with straight uprights or housing that enclose the slides of the die space.
2. Mechanical gap frame presses with uprights or housings (parts of frame) that are open leaving the top of the bed and die space clear for easy access of material. This definition is general and covers both single frame and tie rod frame machines.
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Double Geared Type -
The flywheel is mounted on a separate shaft and a double gear reduction is used to transmit power to the main shaft. This type of press is used on deeper draw work where a considerable amount of energy is required due to the longer distance as well as where the maximum drawing speed of various metals limits the speed of the slide. Double-geared presses generally operate in a speed range of 10 to 30 spm.
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Eccentric Shaft Presses -
These presses are recommended for short stroke work or for high speed operation. Basically the same as the crank press, these presses have an eccentric shaft instead of a crankshaft. The use of the eccentric shaft reduces the effect of bending on the main shaft thus making the shaft stiffer.
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One Two And Four Point Eccentric Gear Straight Side Presses -
These presses usually have a double geared drive and are used a great deal for medium and heavy blanking, and draw work where long strokes and fairly slow speeds are required.
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Four Point Press -
A press that has four connecting rods between the drive eccentrics and the slide.
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Flywheel Press -
A mechanical press which has the flywheel mounted directly on the main crank or eccentric shaft without gearing. Sometimes called a plain or non-geared press. This press model is primarily for blanking and piercing operations where energy requirements are comparatively small and where the press operates at a fairly high speed (90 spm and above).
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Gap Press -
A general definition of presses in which the uprights or housing are made in the form of a letter
C making both ends of the die space accessible.
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Geared Press -
A mechanical press with a main crank or eccentric shaft connected to the driving source by one or more sets of gears. A triple geared machine will have three sets of gears and pinions and four driving shafts including the main crankshaft. A twin geared press has two main gears on the crankshaft meshing with two main pinions on the first intermediate shaft.
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High-Speed (instead of Production) Press -
A specialized design of automatic mechanical presses with rigid frames and comparatively lightweight slides and parts designed for high speed. These machines have a comparatively short stroke, are built in one-piece or built-up frames and arranged with various types of feeds to meet customer requirements.
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Hydraulic Press -
A press whose slide or ram is actuated by hydraulic cylinder and piston whose pressure is obtained from a hydraulic pump. The press cylinder, the pump, and the fluid
(usually oil) under pressure, together with connecting valves and controls from a hydraulic system which theoretically acts in accordance with the hydraulic principle.
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Inclinable Press -
Small and medium size mechanical crank presses which can be inclined or tilted backward to facilitate ejection of finished parts by gravity. These presses are usually open-back, gap frames with a right to left crankshaft up to 200 tons. Typically used in the upright or vertical position, these presses are readily adjustable, usually by a hand mechanism, to any desired inclination up to 45 degrees. The inclinable press is widely used, being particularly suited to blanking, piercing, forming and shallow drawing operations for a variety of small and medium size parts. This type of press is usually equipped with a mechanical feed for rapid automatic production.
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Knuckle Joint Press -
(Also called Embossing or Coining Press) - A heavy, powerful comparatively short stroke mechanical press in which the slide is directly actuated by a single toggle (or knuckle) joint, closed and opened by means of a connection and crank. Available in 30 to 3,000 tons, the knuckle joint press is used for embossing, coining, sizing, heading, swaging, and extruding.
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Open Back Inclinable Press -
An open back inclinable gap press with a one-piece frame that has the opening at the back between the two gap uprights usually slightly more than the left to right dimension of the slide flange. Commonly referred to as an OBI Press.
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Punch Press -
1. Punch (or punching) press is the name given to an end wheel gap press of the fixed bed type. Used for piercing (punching) operations.
2. The name is used loosely to designate any mechanical press.
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Progressive Die Presses -
These presses are commonly used for producing finished parts from coil, and are also referred to as high speed presses or high production presses. They may be single or double crank, eccentric shaft, straightside presses and are equipped with an automatic coil feeding mechanism. The design of this class press takes into consideration the additional accuracy and rigidity required by progressive die operations.
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Servo Press -
A mechanical press whose flywheel, clutch/brake and main drive motor has been replaced by a servo motor drive system to provide total programmability of the press stroke, speed and slide motion profile.
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Single Action Press -
Any press with a single slide and usually considered to be without any other motion or pressure device which would affect the press working on the part.
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Single Geared Type -
The flywheel is mounted on a separate shaft and a single gear reduction is used to transmit the power to the main shaft. This type of press is used for shallow draw work, forming, and similar operations requiring considerably more energy than is available on the flywheel type press. In this type of press strokes per minute is generally in the range of 30 to 90 spm.
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Single-Point Press -
A mechanical press in which the slide is operated by one connection.
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Straightside Press -
Any mechanical press with uprights or housing with plain, flat sides (usually vertical) enclosing the left and right sides of the die space. This classification of presses includes many types and designs, such as single crank, double crank, eccentric, level, four point and enclosed presses.
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Two-Point Press -
A mechanical press in which the slide is operated by two connections.
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