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Old June 20th 04, 09:07 PM posted to uk.transport.london
Terry Harper Terry Harper is offline
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First recorded activity at LondonBanter: Jul 2003
Posts: 359
Default Gearboxes (was Routemasters in Niagara Falls)

"Martin Underwood" wrote in message
s.com...
"Clive" wrote in message
...
In message m, Martin
Underwood writes
Do crash gearboxes actually engage the teeth of the gearwheels or do
they engage dog-clutches (ie like a synchromesh box except without the
synchromesh cones)?


Cog meshing went out in the 1920s and since then it has always been
dogs.


So, given that post-1920s gearboxes had permanently-engaged cogs, of which
one at a time was locked onto the shaft by dog clutches, why did it take

so
long for manufacturers to add that other little refinement, synchromesh
cones?


Just had a look in Alan Townsin's "The Bristol Story, Part 1", which has a
picture of a KS-type 5-speed gearbox, with its top cover removed, on page
58.

That had constant mesh 3rd and 5th gears, direct drive 4th gear, and sliding
mesh cogs for 1st and 2nd. It was superseded in the 1950s by a synchromesh
version.
--
Terry Harper, Web Co-ordinator, The Omnibus Society
75th Anniversary 2004, see http://www.omnibussoc.org/75th.htm
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