Bracehand Ltd is the decendant of "Smart & Brown
Formally of London Road, Biggleswade, Bedfordshire.
The L Model
The Smart & Brown 10245.5" x 24" toolroom lathe was manufactured from
the late 1950s and until the early 1990s (in variable-speed drive form) - and is still very much sought after today as an
example of a machine tool which was produced to the highest possible standards and not down to a price. On the original
Mk. 1 model 12 spindle speed were available, from 30 to 2500 rpm, and the headstock pulley ran on its own ball journal bearings
concentric with, but independently of, the main headstock spindle.
A 3-speed, 3-phase motor rated 1/1.5/2 H.P. was located
in the base and drove upwards to a two speed gearbox which incorporated a multi-disc friction clutch to smooth out the speed
changes. The speed-change gearbox was operated by a lever and all speeds could be changed without having to move a belt
from pulley to pulley.
The heat-treated spindle with a Type D1-4" nose and running in SKF type N.N.30.K double-row
cylindrical roller bearings was bored
1 1/4" and accepted collets up to 1" in capacity. Filtered oil was pumped
automatically to the headstock, speed-change and screwcutting gearboxes whilst the apron was lubricated by a small pump contained
within its base which was activated by the sliding action of the carriage assembly.
The lathe bed was constructed from
a high-grade nickel iron, machined and flame hardened, provided with what the designers
considered the best combination of V and flat surfaces to locate and maintain the relative positions the headstock, carriage
and tailstock over a very long service life. The lathe was mounted on a cast-iron base of great weight and rigidity.
Mk. 2 version was produced as the "1024 VSL" which, whilst having the same capacity and being mechanically almost
identical to the Mk. 1.The overall view of the Mk 2 was enhanced to give the more modern look by altering the rounded shapes
of the headstock ,tailstock and top slide castings to a more appealing square shape this made it look modern
with a tool tray cast into the headstock lid, it was fitted with a very effective push-button-controlled variable-speed drive
unit that gave both forward and reverse speeds from 40 to 2500 rpm from a 3-phase, 3 hp (2.25 Kw) motor.
micrometer dials and a coolant system were fitted as standard and the automatic lubrication of the leadscrew, saddle, apron
and headstock was carried over from the Mk. 1.
Smart and Brown concentrated on toolroom-class lathes. They quickly developed a range of ingenously
designed machines which found favour in toolrooms and research departments all over the world. All Smart & Brown lathes
were superbly finished, built to the very highest standards and included many thoughtful touches to help the operator.
Smart & Brown craftsmanship and precision, is built into every Pultra Lathe.
It is suitable for use in
the instrument or production shop and capable of turning to very fine limits.
Incredible versatility can be obtained
with interchangable compound slides, cut-off slides, tailstocks and capstan slides and there is a full range of equipment
for drilling,milling and grinding.
Drive units for both bench and cabinet mounted lathes give a choice of speeds
between 240 and 6000 RPM.
Headstock parts are run in before final assembly.
Metric or English graduated
machines are available in bench or cabinet versions.
The Pultra Micro Lathe is capable of handling a wide variety
of componants from 0.4mm bar up to 700mm chuck work.
This was Smart and Browns most powerful Lathe it was built to celebrate 40 years, it was reported to take a 1" cut
on dia without even a flicker from the amp meter.
The name 400 is in relation to the swing over the Bed (400mm)
It's power unit was a D.C SHUNT wound with thyristor, it's frame was a D160 foot mounted with Force vent cooling
side mounted fan, giving with the controller a speed range of 50 to 4,700rpm at 50Hz Field weakening to give 10.7 Kw
(14.3 hp) at 1000 rpm.
The 1000mm between centres model weighed in at 2.7 tons, the 1500mm at 2.9 tons
|The last 400 to be built leaves the factory
The System 'L'
System 'L' is a concept providing a comprehensive collection of precision engineered modules which can be assembled
into a lathe of different configerations to suit customers machining requirements.
The 'L' lathe can
be tailored for precision turning or second operation production work.
Smart & Brown 'L' lathes can
be supplied with 12 spindle speeds from 150 to 3000 r.p.m. forward and reverse.
A 4:1 reduction is immediatly available
by motor switching and an automatic brake provides spindle stop.
Alternatively a 3 speed non reversing drive can
Other drive motor configerations are available on request.
All attachments are fully interchangable
making it possible to convert your machine to any other 'L' type configerations very rapidly. Equipment can be supplied
and fitted to handle a wide variety of componants.