Originally Posted by drew23
... I wonder why Robertson heads didn't catch on in the States - they're superior in a few ways; easier to stick on a driver tip, harder to strip, , cheaper to make. I suspect it's some kind of legal
Commerce trumped Engineering.
Peter Lymburner (P.L.) Robertson of Milton, Ontario
, invented the Robertson screw and screwdriver in 1908.
The square slot is tapered inward slightly, and the screwdriver head
is also tapered to match. This provides a tight fight with the screwdriver head. This means that you can place the screw on the driver, hold the screwdriver horizontally, and drive the screw with one hand. The tight fit makes it far less likely to strip the head on a Robertson screw than a Phillips screw. The Robertson screw accounts for 85% of screws sold in Canada.
There is an inferior American version of the Robertson, without the taper; requiring the screw socket to be slightly over sized (compared to the driver), which greatly increases the chance of stripping the screw.
Robertson licensed his screw to companies in Europe
, including a British company that deliberately allowed their company to collapse - and then snatched up the license
from the trustees at a bargain. Robertson spent years and a small fortune in court in order to get back the license
In the U.S. Henry Ford tried the screw, and discovered it shaved two hours off the assembly time of his vehicles. He wanted to license the screw from Robertson, so that he could make sure the screws were available, and so he could control their manufacture (ensuring his manufacturing advantage). Due to his bad experience in Britain, Robertson refused.
Later, the inferior Phillips screw came along, and was licensed to Ford.