Jump to content

Magnetic switchable device

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by MyOrbs (talk | contribs) at 13:28, 30 November 2023 (Restructured, added references.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
A magnetic switchable device with a post attached, as used in the engineering metaltrades.

A magnetic switchable device (often called a magnetic base) is a magnetic fixture that uses one or more permanent magnets in a configuration that allows the external field to be turned on or off. They are used in many applications including optics, metalworking, lifting, and robotics, to attach items to metal surfaces in a secure but temporary way.[1][2]

Principle of operation

A switchable magnetic device usually consists of a a magnetic circuit with permanent magnets. By moving some parts of this circuit, the magnetic flux can be directed within the device (off position) or externally (on position) [3].

One type of magnetic switchable device is made from two blocks of iron, with a round cavity bored through the center. [1] The halves are joined together with a non-ferrous material such as brass or aluminium. A round permanent magnet is inserted into the bored hole and a handle is attached to allow rotation of the magnet. This act of rotation changes the orientation of the magnetic field.[4]

In the off position, the poles are oriented towards the non-ferrous core. The iron blocks act as keepers by bridging between both poles.

In the on position, the poles are each in one iron half, which then acts as an extension. The field is effectively passing across an air gap (at the base and top). If this gap is bridged with a piece of iron, it becomes part of the magnetic circuit and will be fixed to the structure.

Base and magnet assembly. Shown in the inverted position.
Magnet in Off position. Iron blocks act as keepers.
Magnet in On position. Iron blocks act as extension of magnet.


Applications

Switchable magnetic devices have seen applications in climbing robots, where the magnetic device acts as a gripper [1][3].

Switchable magnetic devices are also commonly used in tool fixtures, with applications in machining and metalworking.[5] The magnetic base may have a V cut into the bottom of the base or the back. This V allows the base to be attached to a round bar such as the column of a drill press or a pipe. In such cases the swithcable magnet is present in the base of the tool fixture, and an arm with swivels is attached to it. Some of these swivel devices can be actuated by a single screw mechanism [5].


References

  1. ^ a b c Rochat, Frederic; Schoeneich, Patrick; Bonani, Michael; et al. (1 August 2010). "Design of magnetic switchable device (msd) and applications in climbing robot" (PDF). Emerging Trends in Mobile Robotics. WORLD SCIENTIFIC: 375–382. doi:10.1142/9789814329927_0047. ISBN 978-981-4327-97-8. S2CID 11278115. Retrieved 28 November 2019.
  2. ^ "Shipbuilding And Shipfitting Magnets". Magswitch Technology. Retrieved 2019-11-29.
  3. ^ a b Peidró, Adrián; Tavakoli, Mahmoud; María Marín, José; Reinoso, Óscar (2019). "Design of compact switchable magnetic grippers for the HyReCRo structure-climbing robot". Mechatronics. 59: 199–212. ISSN 0957-4158. Retrieved 2023-11-30.
  4. ^ United States US7012495B2, Perry J Underwood & Franz Kocijan, "Switchable permanent magnetic device", published 2005-01-20 
  5. ^ a b Dunki, Quinn (2019-02-18). "Metal Lathe Tutorial 11 : How To Buy And Use Indicators" (video). youtube.com. Retrieved 2023-11-30.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Magnetic_switchable_device&oldid=1187633503"