What is easier to lift? A 10 Kg mass of steel or 10 Kg mass of cotton wool?
You are correct if you said that this was a trick question—both weigh equally. However, some people take it one step further and realize that lifting is only possible once you are able to properly grab a load of weight. Grabbing an object is not always easy, and especially when you want the job done by automated machines. That used to be a problem in some industries where metal sheets and blocks had to be lifted, and automatically, under computer control. Various techniques have been tried including vacuum cups and electromagnets to grab materials with variable success.
The action has various sensitive aspects:
- Reliability- The grip and release action must be reliable, each and every time.
- Weight and size of the holding fixture- The fixture must be small and light in comparison with the object to be lifted.
- The Operating Mechanism- The holding fixture is always supported at the back end by some mechanism, whether hydraulic or electromagnetic. That is generally, much bulkier.
- Safety- This aspect is paramount. Erratic gripping can cause an untimely release resulting in very unfortunate or costly accidents. The lift and transport operation must be absolutely reliable.
- Cost-effectiveness- Ultimately, money makes the mare go. All these concerns must be must be satisfied at a competitive cost.
Where ferrous metals are concerned, gripping is possible using magnets. Magnetic “gripping” structures make life easy. They don’t have fingers, even two arms. But they do have invisible magnetic tentacles (what the engineers call lines of force) which grab ferrous materials. They grab and release on order, (without manual effort), and that is the principle of the equipment offered by the reputed manufacturer Magswitch. Magswitch offers a variety of holding fixtures internationally, including jigs and fixtures for tabletop working, welding, woodworking, and for lifting and placing.
When talking of magnetic grip and release, one would straightaway think of electromagnets. Electromagnets have indeed given very good service over the years and the decades, but they have certain disadvantages. They have to be carrying huge currents when magnetized. Switching huge currents on and off was power intensive and demanded large structures.
Permanent magnets are relatively much lighter, and do not require continuous electric supply for a continued grip. One would expect that a permanent magnet will grip when it comes sufficiently close to a ferrous object. That is true. But how would we ensure it releases when we want it to? How do we ‘demagnetize’ it? In other words how do we switch the grip of a permanent magnet.
Switching a Permanent magnet
Magswitch has made a very ingenious use of a principle employed in old-time computer core memory to solve this problem and obtained a patent for it. Recall that 1+1+2, and 1-1=0. That is the principle used by Magswitch. Two identical permanent magnet poles are used. When in alignment, they reinforce each other to grip the material. When, one is rotated to opposite alignment, the two cancel and the net result is to release the grip. There is no requirement for a holding current as in the electromagnet. Just the current required to rotate one pole, and only till alignment is complete!
Heavy Lift Frames Series by Magswitch
One of the product lines by Magswitch is the Heavy Lift Frames Series. These lift frames by Magswitch are suitable for lifting up to 8000 pounds of pipes, beams, or sheets. Sheets as thin as ¾ inch (19 mm) can be lifted singly through their patented shallow field technology. Like all other magnetic products by Magswitch, the Heavy Lift Frames Series offer very special advantages over other types of holding arrangements.
- Lightweight- Magswitch lifters are nearly 50% lighter, and in some cases, even more. This makes the overall lift mechanism much lighter. It also makes the operation safer.
- Convenience- Compared with slings, the system is much better adapted to automatic handling, thus improving process efficiency and reducing cost.
- Safety- Safety is very important when using automated magnetic lifting. Magswitch lifters are very safe, and can be used even in handing sheets or other thin materials (1 inch or less). These lifters are stronger on thinner materials. A battery protects against possible accidents due to power failure. This failsafe arrangement provides enhanced workplace safety.
- Easier actuation- Compared with electromagnets, these are easier to actuate.
- Enhanced automation- Need for strapping is eliminated, whereby automation is enhanced.
- Onboard battery- Onboard placement of the battery makes for a more compact tool while protecting against unexpected power failures.
- Dual Purpose connection- The frames can be lifted (with their loads) using either under hook or forklift.
- Shallow field Technology- This is a special by Magswitch. When de-stacking relatively thin ferrous sheets magnetic tools have a problem. The force penetrates to more than one sheet. Magswitch use the technique of ‘shallow (magnetic) field so that the equipment can grip just one sheet at a time.
- Scalable technology- The lifting mechanism can be scaled to various sizes by adding magnets according to your requirement.
- Cordless Operation- In moving machinery, cables can create tangling and accidents. Initial layout and installation is also more complex. Most products in this series offer a remote-control capability, eliminating these problems.
So, what do you get from using Magswitch Heavy Lift Frame Series?
- Increased productivity
- Enhanced workplace safety
- significant savings in production costs
Interested in learning more? Speak to an ACD expert!
You may also be interested in reading: