IMPROVEMENTS IN LATHES
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by George Dacre at the Office of
the Commissioners of Patents, with his Petition, on the 30th October
1866.
I, GEORGE DACRE, Master of Arts, Chaplain to the Forces, of Preston,
in the County of Lancashire, do hereby declare the nature of the said Invention.
for "IMPROVEMENTS IN LATHES," to be as follows:-
This Invention relates to certain improvements in the construction of lathes,
the object being to turn any material of any diameter with a speed and force
exactly proportioned to each material and each diameter, and (the Invention
being equally applicable to lathes driven by foot or power) to reduce the force
or power necessary to turn lathes.
The lathe frame consists of four standards set on a foundation and con-.
nected by longitudinal and transverse bars; on the upper side is carried
an overhead shaft projecting on either side, and within the lower part
is contained a treddle motion. On the crank shaft, to which motion is
given by the treddle, is keyed between an independent fly wheel and an outside
bearing of the shaft (all without the frame) a drum or pulley for the
purpose of giving motion to the overhead shaft by means of a belt passing
round the drum and loose and fast pullies on the overhead shaft. Motion
may also be given to the overhead shaft directly or indirectly from a steam
engine by means of a belt passing round these loose and fast pullies. In place

page_text: of the double gearing of lathes, as at present constructed, the spur wheel keyed
on the lathe mandril is geared by a second or intermediate spur wheel to a
third spur wheel (of the same diameter as that on the lathe mandril) keyed on
a shaft in rear of and parallel with the lathe mandril, extending the length of
and projecting beyond the left standards of the lathe frame, Figs. 1 and 3.
On the left extremity of this rear shaft and outside the frame is fixed by set
serews or a travelling key a large spur wheel, Fig. 3. Motion to this spur
wheel, and by it to the rear shaft, and thence by the spur wheels to the lathe
mandril, is given in the following manner :-On the left extremity of the
overhead shaft and outside the frame is keyed a cone pulley, which com-
municates motion by means of a band or belt to a second cone pulley (loose)
revolving on a stud fixed to and projecting from a perforated plate screwed or
bolted outside of and to the transverse bars of the frame (or otherwise as may
be most convenient) the stud being situated below the overhead shaft and
vertically above the rear shaft, on which is fixed the large spur wheel, Figs. 2
and 3. On the boss of this second or lower cone pulley is fixed by a key or
set screw a champ spur wheel or pinion, which gears with and gives motion
to a second change spur wheel revolving on a stud (moveable) situated below
the stud carrying the cone pulley and capable of being fixed to any part of
the perforated plate; on the boss of this second change spur wheel is fixed
by a key or set screw a third change spur wheel or pinion, which gears with and
gives motion to the large spur wheel fixed on the left extremity of the rear
shaft, and thereby to the lathe mandril by means of the rear shaft and the
spur wheels previously mentioned, Figs. 2 and 3.
The lathe bed, and back lathe head or poppet, and other parts of the machine
need no description; the main features of the Invention consisting in com-
municating motion to the lathe mandril by means of the shaft in rear of and
parallel with the lathe mandril, and the application of the system of change
wheels, by which a variation in speed and force exactly proportioned to each
material and each diameter, and an economy in the force or power expended
in turning lathes is effected as first herein stated.