Robert Barron and the Double-Acting Lever Lock (1778)

A Family of Braziers

The fullest account of Barron's life comes from The Lock Collectors Association (LCA). Robert and his brother Francis took over the family business of braziers and ironmongers on the Strand in London after their father's death in 1763. They traded as Francis and Robert Barron. Robert married and left the firm in 1776 to live at Bowling Green Row, Hoxton, in Shoreditch. The LCA says he developed the new lock and obtained the patent there. He moved to 66 Barbican in 1781. Shortly before his death in 1794 he was living at 75 Wood Street, off Cheapside.

Francis kept the Strand business going and was listed in 1790 as ironmonger and brazier to the King. The LCA notes a lock of about 1790 marked "F. Barron, Strand" that carries the Barron patent mechanism. This suggests that Francis may have made his brother's locks, though the record is too thin to be sure.

The 1778 Patent

All the sources agree that the patent was granted in 1778 and was numbered 1200. They do not agree on the day:

• The LCA, citing its own earlier research in The Lock Collector (issue 8, 2005), gives 27 February 1778.
• George Price's 1856 Treatise on Fire & Thief-Proof Depositories and Locks and Keys heads its description "Barron's Lock, Patent dated October 31, 1778." The collector site antique-padlocks.com also gives 31 October 1778.

Price also corrected an older mistake. He noted that most writers before him, including Charles Chubb, had dated Barron's patent to 1774. He also rejected the idea that George Black, who held a 1774 patent for "locks and latches," had invented the double-acting tumbler that Barron then improved: "there is nothing whatever to support such a supposition." This article gives the year 1778 and leaves the exact day open.

How the Double-Acting Tumbler Worked

The following description stays at the level of principle. The LCA describes Barron's original lock as having two tumblers. Each carried a projecting stump. The key had to lift both tumblers to a precise height, so that the stumps could pass through a gating, a shaped opening cut in the bolt, and let the bolt slide.

The phrase "double-acting" refers to the precision this demands. In Wikipedia's summary, the slot meant that "lifting the lever too far was as bad as not lifting the lever far enough." In other words, the tumbler had to stop in exactly the right place. Price describes the step as Barron adding the tumbler principle to the warded lock. He quotes Barron's specification claiming "the gating or racking" of the tumblers.

Barron kept wards in his locks too. The LCA suggests that this was partly to reassure buyers who still trusted wards. The collector description on antique-padlocks.com also describes a Barron-type mechanism combining wards with two levers.

Influence

The LCA says the basic principle carried on into modern lever locks with two changes. The stump was later placed on the bolt rather than on the levers, and more levers were added for greater security. Jeremiah Chubb's detector lock of 1818 used a set of levers. Wikipedia's account of it says Chubb built on earlier work by Barron and Bramah, and added a mechanism that jams the lock if a lever is lifted too far. Joseph Bramah, by contrast, took a different route in 1784, using a cylindrical key and sliders (see Bramah lock).

Price called Barron's 1778 patent "the first great improvement in the art of making locks secure." That is a contemporary judgment, quoted here as one. It is still a fair summary of why Barron is remembered.

Barron's Principle Today

The LCA notes that the same precise-lift principle is still used in modern lever locks, which usually have more levers than Barron's two. A common point of confusion is the British standard BS 3621. It is a performance standard for thief-resistant lock assemblies that need a key to lock and unlock from both sides. It does not prescribe a lever mechanism, and cylinder-based assemblies can also meet it (BSI). For the comparison with pin tumbler designs, see pin tumbler lock and warded lock.

Related Topics

• Lever Tumbler Lock
• Warded Lock
• Jeremiah Chubb
• Joseph Bramah
• Padlock
• Notable Figures

Sources