The Bramah lock gave a new level of security to boxes. The presence of a Bramah lock which were complicated to manufacture is almost a sure sign that the box with it was intended for the quality end of the market.   
Origin: United Kingdom
Circa: from 1784. 
Materials: brass and steel

The story of Joseph Bramah's locks begins in 1784 when he was granted letters patent for "a LOCK, constructed on a new and infallible Principle, which, possessing all the Properties essential to Security, will prevent the most ruinous Consequences of HOUSE ROBBERIES, and be a certain Protection against Thieves of all Descriptions". 

The lock was not Bramah's  only successful  invention. Some 6 years earlier he had invented an early form of flush toilet (1778), but that is another story. Later he invented a printing press for banknotes.  

Bramah was born in in 1748 into a Yorkshire farming family. When he was 16, an accident left him lame. Unable to continue farm work he was apprenticed to the village carpenter. 

He came to London as a journeyman cabinetmaker. 

 Much of his work was developing tooling for manufacturing processes. He employed both Henry Maudslay and Joseph Clement. in his workshop. Maudslay went on to invent a super accurate micrometer. While he worked for Bramah he is credited for having made many of the specialized machines needed to make the Bramah lock. In 1810 he was dismissed by Bramah when he asked for a rise.  He set up his own  precision workshop. 

In 1784, The Bramah lock company  opened in Denmark Street but quickly moved to  124 Piccadilly. 

In 1798 the patent was extended for a further 14 years.

The Bramah lock is immediately recognizable.  

Some examples of Bramah locks on boxes.

Important brassbound Figured Rosewood writing box with matched Bramah locks Circa 1819

Exceptional kingwood and brass inlaid box circa 1820 with rare secret compartment.

A fine Antique brass edged Rosewood box Circa 1840.

A Very High Quality Brass bound London maker Coromandel Dressing Box circa 1859 with gilt silver.

A fine Antique brass edged Rosewood box Circa 1860

A fine Antique brass edged Coromandel box Circa 1860.

A Very High Quality Brass bound Coromandel Dressing Box circa 1884

A dramatic high quality figured walnut dressing box with chassed silver plate top crystal bottles and drop front Circa 1895

 

See also: The Tompson patent box lock

Acording to  the Dictionary of English Furniture Makers, 1660-1840, ISBN0901286184The company traded as "Bramah, J &Sons "patent Engine Lock & Water Closet Manufacturer". 

The Windsor Royal Archives (  RA 35513; 35521;-27; 39 -47; -60, record that he supplied the Royal Household with "a 'Morocco Soufflet' writing boxes, and inkstands to the total of £593-2s." (

The Bramah lock was truly inventive and a complete departure from the locks that had existed before. Many box locks were very simple and could easily be opened with a lock pick. 

In his dissertation, Bramah tells us "that no invention for the security of property hath yet been offered to the world, which the ingenuity of wickedness hath not found means to defeat. "  

Some references used in the preparation of this page.

http://www.antique-locks.com/bramahbook.htm  This is Joseph Bramah's Dissertation on his lock invention in full. This link no longer works if anyone has a new link please let me know.

The story of  Hobbs picking the lock is reproduced at: http://www.antique-locks.com/viewtopic.php?f=2&t=218&p=463#p455 

http://www.antique-locks.com/viewtopic.php?f=2&t=150   This is a good guide to dating Bramah locks. 

http://www.localhistory.scit.wlv.ac.uk/Museum/locks/gazetteer/gazbra-bzz.htm 

http://www.crypto.com/photos/misc/bramah/  Matt Blaze examines a modern Bramah lock. the design principle has hardly changed since the early 19th C 

http://en.wikipedia.org/wiki/Joseph_Bramah 

This is the dismantled locking mechanism  the main  lock from an Important brassbound Figured Rosewood writing box with matched Bramah locks Circa 1819.

The lock plate reads just Bramah. There is a second Bramah lock on the drawer. When this box came into our possession  the drawer was locked and the keys were lost. I hoped that the two locks were on suite and that by making a key for the main lock which I could take apart it would also fit the lock in the drawer. 

It did!

The lock can be dated because of the "Bramah" marking and the presence of the false notches on the sliders. The sliders are made of a folded over piece of steel and not just flat pieces of steel. 

The lock  has only one spring to raise the sliders. This was an innovation introduced about 1815, and  the false notches in 1817.

   

The inset drawings are from Bramah's 1784 patent. The similarity to our lock is clear. The main difference is that in the 1784 lock each of the sliders is separately sprung. 

The presence of  the notches and the single spring made the lock even harder to pick.

On the post 1815, single spring design the spring is used to reset the lock, raising all the sliders when the key is withdrawn.

When the correct key is inserted into the lock the deep notches on the sliders align with the plate and allow the cylinder to be turned.

 This picture shows the plates which slot into the cylinder. When the key is removed the sliders are aligned with the cuts in the plate.

In this lock the two plates are symmetrical. In later locks the plates are divided differently.  

See below for pictures of  a later lock below.

The two plates are symmetrical at this date.

These are the sliders removed from the cylinder.  I marked the sliders and their slots with a write on all surfaces pen so as not to mix them up. 

In this photo I have aligned the slots. The upper surfaces will be the relative depth of the key slots.

In a Bramah key the the slots are cut into the barrel. the tennon  is simple.

There is a picture of the key at  Important brassbound Figured Rosewood writing box with matched Bramah locks Circa 1819

 The picture shows the main block. this would have been cast and then turned and milled.

the sliders can be seen through the keyhole.

End view of the key. The slots will match the heights of the sliders. 

This lock has 5 sliders. 

The plates are no longer divided symmetrically. Nor are the screws opposite each other. 

 The slider  are made of a piece of steel folded over. Here the slider is in the locked position

 The picture shows the main block. this would have been cast and then turned and milled. the lathe marks are clearly visible. Except for the asymmetrical placement of the screw holes   it is very similar to the lock of 1819.

The 1784 lock.