Sidleen rim nightlatch and Ingersol connection

[chubbbramah]

This cylinder rim nightlatch came off an outer London tower block of flats, built I guess c1960, in 1969, after a wave of burglaries in the block.
There is no deadlocking function, and no marking on the latch. The aluminium cylinder was marked 'Sidleen'. The pull-up linterior latch handle, and snib, appeared to be a 'wannabe' Ingersol SC71 rimlatch. I have never seen another like it.

And neither had anyone else who saw it on the Lock Collectors' stand at several trade shows. Without considering of much interest, but it was small and easily accessible at home, I took it to a Lockex, together with a couple of Ingersol Impregnable cylinders. I was surprised at the interest in them.
Later, Andrew Taylor (Jack Taylor's son) told me that his father had briefly worked at Sidleen, and my rimlatch seemed to be a short test run for the latch handle and snib that would later be used on the Ingersol rimlatch.

I had previously only known Sidleen for the tubular lock (9 or 10 pin, I forget which) fitted to parking meters
https://collection.sciencemuseumgrou...locks-and-keys
http://www.historywebsite.co.uk/Muse...tteer/gazs.htm
became Sidlock. They do not appear to be still trading.
Pictures to follow.

[chubbbramah]

This is the apparently uncommon Sidleen nightlatch: has anyone else seen one in service?

[chubbbramah]

I can no longer remember where I found the cylinder shown on the right. It has evoked some interest at shows, as it is an early cylinder without the steel cover. Additionally, it has only 2 fixing screws.
Soon after the Impregnable cylinder appeared, one was subjected to an unforseen attack. This was countered by adding the domed steel cover. And 2 additional fixing screws were added, as on the left cylinder. It was found that many decorative finishes did not last well when applied to the hard steel cover, so the range offered was reduced.

Just noticed I have been mis-spelling throughout: should be Ingersoll with 2l's.

[Huw Eastwood]

I can no longer remember where I found the cylinder shown on the right. It has evoked some interest at shows, as it is an early cylinder without the steel cover. Additionally, it has only 2 fixing screws.
Soon after the Impregnable cylinder appeared, one was subjected to an unforseen attack. This was countered by adding the domed steel cover. And 2 additional fixing screws were added, as on the left cylinder. It was found that many decorative finishes did not last well when applied to the hard steel cover, so the range offered was reduced.

Just noticed I have been mis-spelling throughout: should be Ingersoll with 2l's.

c1947~52 as I'm pretty sure it was late 1952/3 when the design changed as a result of a spate of London burglaries in the late 1940s.
There's actually quite a story behind it which pushed Jack Taylor to revise the original exposed cylinder/plug design, and add the additional armoured rose.

The design changed a lot from the original and the differences are quite noticeable if you take one apart and compare them with a later example like your photo.

• The sidebars were originally unsprung. The brass housings had distinctive internal annular grooves in the back face to guide a projection off the floating sidebar. This feature was changed in favour of a sprung sidebar with ramp action and without the guide grooves in the housing.
• The housings were originally solid brass and clearly marked 'top' to facilitate correct installation. Later changed to zinc alloy die-castings.
• The Levers were also solid brass which were later changed to nickel silver.
• The cylinder plugs were 2-part with very
  thick solid-brass fronts, later changed to the one-piece zinc alloy die-castings with thin pressed-on caps.
• Two threaded fixing lugs only (as already mentioned), later changed to four.
• Also (as already mentioned) the exposed cylinder fronts were covered by an additional armoured rose as a result of the spate of successful attacks on the locks in the late 40s.

The story behind the burglaries which prompted the Ingersoll design changes is out there somewhere, it's definitely worth a read if you find it.