Fourslide vs. Punch-Press
Fourslide vs. Punch-Press
What is a punch press? What can it do? What can’t it do? To put it as briefly as possible, it is a stamping plant in itself. Set in a progressive die, and it will blank out metal parts and stampings.
But, such a press has its limitations-because it has tool motion in only one direction it cannot, in itself, make certain forms or bends. These have to be taken care of by special cams and slides built into the die.
And that’s where the fourslide has the advantage, combining the features of the punch press, cams, slides; stock straightened and slide feed into one machine. A fourslide has all this and more.
Even a press head is available for fourslide, in 2 to 100 tons. The fourslides has four cams and slides, set 90 degrees apart, and each can be timed at any point in 360 degree of shaft rotation, with reference to the press head.
Needs Understanding
Yet the fourslide and its capabilities are not as well known as those of the punch press. Many shop men define it vaguely as one of those special machines that come tooled and ready to work on special long run jobs. They cost plenty? Of fourslide? It has something or other to do with forming wire or flat stock.
Let’s take a look at the fourslide and what it can do.
Take the slide feed, which can handle wire as well as flat stock. Here, the adjustable gripping jaws pressure on the material is positive and cam-controlled on the forward feed stroke, and it releases on the return stroke. A separate, cam-controlled adjustable stock checks jaw prevents the material from being dragged back, or from drifting.
Stock straightened? The fourslide has a two plane, 10 to 18-roll straightener that handles wire, as well as flat stock. And the fourslide has a variable speed drive to handle many different jobs.
And here is the “and more”: the fourslide also has two adjustable cam-controlled motions from above; a form lifter (for bending in the opposing plane, or for lifting the king-post form tool), and the stripper. The latter, as its name implies, strips the finished, formed stamping from the mandrel.
To round off the list of standard fourslide equipment, the machine has another slide, the primary cutoff, which is also cam-controlled and is laterally adjustable in either direction on the bed area, so that it can part the stamping from its strip before forming.
What do all these mechanisms accomplish? Just this: no more building of cams and dies for certain formed stampings – a job that involves a big dollar outlay for the press tools.
In addition to the standard equipment listed, there are many optional accessories. For instance, there is a secondary cutoff for notching, close control of length, and other operations. A nail-pointing attachment points stock or cuts material from above, instead of horizontally. Hoppers can be adapted for assembly operations, and holes can be tapped with tapping attachments. Spot or butt-welding can be done before, during, or after bending.
Does this mean you should sell your Punch Presses and buy Fourslides? By no means. Actually, both the punch press and fourslide are important in producing metal stampings. The fourslide, however, can produce a large number of formed stampings at lower costs with simpler tooling.
Simple Tool Blocks
Fourslide tooling is designed and built to go on each slide as separate tool blocks for bending or forming, as required. For pushing off the formed stampings, a stripper is attached at the king post, where mandrels are located.
After the slide feed pulls the strip material off the stock reel and through the straightener, the material automatically feeds into the press area for piercing, after which it continues to the forming area, where it is cut off and formed to shape. Just before final forming by the slides, the blank is held by the front tool against forming mandrels.
Tool Movements
The front tool finish forms the front portion of the stamping, as well as partially bending its ends. At the same time, the cut-off tool retracts, ready for the next cycle. The right and left tools can simultaneously advance to impart another 90 degree bending of the ends inward around the mandrels. Then the back tool advances to finish form the ends of the stamping around the mandrels. At this point, the tool slides retract. The stripper rod is attached to the stripper rod to push the formed stamping from the mandrel through an opening in the bed of the machine into a container.
The same basic knowledge that the tool and die maker and the tool designer have for tooling a punch press is sufficient for tooling the fourslide. In fact, the problems of building tooling are usually simple but perceptive skills are needed.
Our next installment will discuss why it’s better to make a music wire spring on a fourslide instead of using a punch press.
Many formed stampings, whether made of strip or wire, whether completed parts or just components can be produced by a fourslide as well as on a punch press. But if the job can be made on either of the machines, it is necessary to know the capabilities of each in order to choose which can do the job most efficiently and economically.
Today, increasing competition and a shortage of skilled labor have combined to put pressure on tool and die makers, tool designers, and plant engineers to produce parts faster and cheaper, and at the same time save on material.
And that’s where the fourslide comes in. Trouble is, even though this machine has been around for some 80 years, few shops know how to use it effectively. Admittedly, there are a number of knowledgeable job shops that use fourslides, but most other plants don’t seem to realize that they can produce complex parts on a fourslide with simple tooling at low cost, and on a short lead time.
Over the years, the fourslide has become a one-machine automated production line: raw stock is fed into it, and a completed part emerges with each stroke. It has a certain edge over the punch press in such operations as matching to bending, but that is not to say that generally the punch press is just as efficient as the fourslide when correctly tooled for a properly selected part.
Because of the fourslide’s versatility, the tooling designer is able to develop simple tooling for formed parts, whether they’re made of strip or of wire. Certainly, a music wire formed part would be a tough job for a punch press. But it’s a breeze for the fourslide.
Let’s put it another way: punch presses and fourslides can work side by side, if each is doing the work to which it is best suited.
Many job shops today have a wide range of fourslides, so as to give them a choice that is dictated by the size of the part to be made and the tonnage required.
In all fourslide models, however, basic operations are the same: a slide feed pulls the material off a stock reel, through a straightener, and into the press head area.
