P. L. Robertson

Illustration from the 1909 Canadian patent for the Robertson screw.

Peter Lymburner Robertson (1879–1951) was a Canadian inventor, industrialist, salesman, and philanthropist who popularized the square-socket drive for screws (often called the Robertson drive). Although a square-socket drive had been conceived decades before (having been patented in 1875 by one Allan Cummings of New York City, U.S. Patent 161,390), it had never been developed into a commercial success, and Robertson's efficient manufacturing technique using cold forming for the screw's head is what made the idea a commercial success.^[1] He produced his screws (patented in Canada in 1909) in his Milton, Ontario factory starting in 1908. The brand has been sold over the years,^[2] and the manufacturing for the present corporation (Robertson Inc) is done in Jiaxing, Zhejiang, China; but the Milton, Ontario, building is still a head office.^[3]

Robertson also wrote a book (short title The Remedy, 1932)^[4] which suggested a strategy to end the Great Depression. It discussed topics including national debts, currencies, and the gold standard.

Robertson was born in 1879 in Seneca Township, Ontario. As a salesman for a Philadelphia tool company in eastern Canadian sales territories,^[5] he was demonstrating tools one day when his straight-bladed screwdriver slipped and cut his hand (a common mishap with the straight slot design). This prompted him to design a different drive for screws that would slip less, leading to his square-socket drive.

Robertson is still remembered by the school in Milton, Ontario, named after him, P.L. Robertson Public School (K-8).

External links

• Peter Lymburner Robertson at collectionscanada.gc.ca

References

1. ^ Rybczynski 2000, pp. 79–81.
2. ^ Rybczynski 2000, p. 85 [footnote].
3. ^ RobertsonScrew.com, http://www.robertsonscrew.com/index.html 
4. ^ Robertson 1932.
5. ^ Rybczynski 2000, pp. 79–86.

Bibliography

• Lamb, Ken (1998), P.L.: Inventor of the Robertson Screw, Milton, Ontario, Canada: Milton Historical Society, ISBN 978-0969562962, OCLC 39913140, LCCN 00-361323, http://www.miltonhistoricalsociety.ca/research/Publications/P.L.%20Robertson/index.html. 
• Robertson, Peter L. (1932), [The remedy]: World reorganization or downfall, and the remedy; a composite picture of the causes of the present disequilibrium in the world—analyzing the extent of war costs, losses, debts, reparations, gold shortage and of the resulting chaos, but with a plan for the redistribution of gold, revaluation of gold, immediate liquidation of debts, a full covering of currencies, and an international coinage., Milton, Ontario, Canada: Author, OCLC 4735733, LCCN 32-020618. [Robertson self-published his book, hiring Davis-Lisson Ltd for the printing.] 
• Rybczynski, Witold (2000), One good turn: a natural history of the screwdriver and the screw, Scribner, ISBN 978-0-684-86729-8, OCLC 462234518, LCCN 00-036988. Various republications (paperback, e-book, braille, etc). 

Persondata
Name	Robertson, Peter Lymburner
Alternative names	P.L. Robertson
Short description	Canadian inventor who popularized the square-socket type of screw drive
Date of birth	1879
Place of birth	Seneca Township, Ontario, Canada
Date of death	1951
Place of death