[timsher]

Animats, your idea is great and it's something we considered a lot when we were thinking about the connector. We almost went and did it. However there were a couple of problems with that patents (as a side note - my co-founder is actually a former patent troll, so we dug quite deeply into the patents). Our priority was to not infringe on any of Apple's patents, so we were as thorough as possible with our research.

Here are the main patents around the MagSafe: http://www.google.com/patents/US7645143 http://www.google.com/patents/US7901216 http://www.google.com/patents/US8087939 http://www.google.com/patents/US8177560 http://www.google.com/patents/US7311526 (the key patent)

Here are the main claims (apart from the one you mentioned): (a) A first connector comprising: a first plurality of electrical contacts, the first plurality of electrical contacts to mate with a second plurality of electrical contacts when the first connector couples to a second connector, wherein the first plurality of electrical contacts consisting of a central contact to convey a signal, two contacts to convey a power supply, one contact on each side of the central contact, and two contacts to provide a return path, one contact on each side of the central contact, wherein when the first connector couples to the second connector, the first and second plurality of electrical contacts define a corresponding plurality of electrical paths; and a magnetic element, the magnetic element to mate with a plurality of magnets in the second connector that are proximally located and arranged in opposing polarities with respect to each other so that when the first connector is brought in close proximity to the second connector, magnetic field lines travel through the magnetic element of the first connector from one of the plurality of magnets in the second connector to another one of the plurality of magnets in the second connector.

(b - part of it) a plurality of movable first contacts to make electrically conductive paths with a plurality of second contacts in a second connector when the first connector is mated with the second connector, each of the movable first contacts biased by one of a plurality of first springs;

The biggest problem is with the claim that speaks about a magnetic field from multiple magnets (4 are present on computer side) traveling through a magnetic element (ie. metal) on the connector side, which the patent states creates a stronger attraction. We thought it would be possible to place metal bits on the connector side in such a way that the magnetic field would only be passing through one element - thus creating less of a magnetic attraction but being a different invention. Unfortunately, at this point it becomes a matter of proving wether or not that's what's actually happening (this was our biggest worry as burden of proof would be on us).

There were another 2 - 4 other claims that also made it hard to improve upon (also not infringe on any of their patents) and create our own connector - not to mention the design patents.

I was actually thinking of writing a blog post about this issue, it was extremely interesting to look into all of this.