Presses are used to shape or resize items through tube or wire upsetting or rotary upsetting. Forging can also change the shape of an item using pipe or rotary presses. Crimping operations use a reducing die and drawing bench trolley to reduce diameter. Rotary heading can forge rounded or pointed ends onto an item using shaped dies and a mandrel. Most presses are cold work machines, but heat may be used in some cases. Internal profiles can also be pressed into hollow bodies using a shaped mandrel.
A press is a device used to shape or change the size of an item by forcing it into a mold or set of molds. These machines fall into two categories: tube or wire upsetting or rotary upsetting. The swage tubes pull the object through a mold to reduce its diameter, while a rotating swage features a series of dies used to hammer the object. Flared parts are typically cold worked although heat may be employed in some applications. Heading machines can also be used to give internal profiles in hollow parts.
Forging is a commonly used industrial process that can reduce the diameter of pipes, rods and wires or change the shape or form of an item. These actions are carried out using two types of machines: pipe presser and rotary presser. The pipe press is a diameter reducing device that works by drawing a part, typically a cylindrical element such as a rod or tube, through a reducing die. Rotary presses employ a series of shaped dies mounted within a cam cage which open and close with considerable force on the workpiece and effectively hammer it into shape. Smaller types of hydraulic presses are also used to secure splice and splice fittings on steel wire rope and electrical wire by deforming a ferrule or lug onto the wire or rope core.
Pipe crimping operations typically begin with the pipe, rod, or wire with the ends reduced in diameter or marked on a rotary press. This reduced end profile simply facilitates insertion into a hardened steel swaging die of the appropriate diameter. Once the material is fed through the die, it is secured to a drawing bench trolley. The trolley is moved by a motorized chain transmission and exerts considerable pressure on the butt, dragging it through the mold and reducing its diameter. When the drawbench mechanism has reached the end of its travel, the slide is returned to its starting position, reattached to the stock, and the process repeated.
Rotary heading is also used to reduce the diameter of the stock, but it can also be used to forge or forge rounded or pointed ends onto an item. The bullet press is a good example of this forging action with solid brass, copper or lead blanks being forged or forged to the correct diameter and tip profile. Rotary presses typically employ a mandrel that supports the stock centered in a group of two or four shaped dies. The dies, in turn, sit within an external cam or lobed cage that rotates about the axis of the mandrel and die. As it spins, it forces the dies against the butt and then off again, sometimes up to 2,000 times per minute.
The constant hammering action of the molds then gives the stock the desired shape. Most types of rotary and tube presses are cold work machines although, in some specific cases, parts may be heated prior to pressing. Internal profiles can also be pressed into hollow bodies with a press with a shaped mandrel which is forced into the hollow body. This is commonly used to flare or bell the ends of steel and copper tubing for some types of fittings.
Protect your devices with Threat Protection by NordVPN
