Slide-rest.
（
Machinery.) A tool-rest employed
[
2209]
for lathes,
planing-machines, etc., in which the tool is securely clamped to a plate capable of motion in one or several directions by means of screws.
In 1648, engravings published at
Rome by Maignan show lathes for turning the surfaces of mirrors, in which the tool was guided by frames so adjustable as to form plane, spherical, or hyperbolical surfaces.
The wheel-cutting engine and fusee-cutting engine of
Dr. Hooke, invented about 1655, had mechanical devices for guiding the tools.
These, as well as the screw-cutting lathe of
Hindley, 1741, and other machines having similar contrivances, were particularly constructed for the use of clockmakers, who were the first to employ special machines in their business.
The first instance of the true slide-rest is shown in the
French Encyclopedie.
This very nearly corresponds with that usually employed in lathes for amateurs by
London makers.
It was adapted to the purposes of machinery by
General Sir Samuel Bentham, who attached it to lathes built for the
British Admiralty previous to 1800.
The slide-rest is the origin of the
planing-machine for metal.
Bentham was also the inventor of the first
planing-machine for wood, patented in
England in 1791, but invented by him in
Russia some years previous.
The sliderest is described in his patent of 1793.
Nasmyth ascribes the invention of the automatic slide-rest to
Henry Maudslay, who certainly greatly improved the lathe.
Maudslay was the pupil and workman of Bramah, and the instructor of
Nasmyth and
Clements.
Before the invention of the slide-lathe, the turning-lathe depended for its accuracy upon the steadiness of the muscles of the workman.
By fixing the turning tool in a rest which is movable accurately in one or another direction, or a line compounded of the two, mathematical accuracy of workmanship is obtained.
Bramah himself patented a slide-rest in 1794.
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Slide-rest. |
In
Fig. 5188,
a is a slide-rest for the foot-lathe.
It has a feather fitting between the two cheeks of the lathe-bed, to which it may be firmly secured by a bolt.
The sliding-plate
d may be moved laterally by the handle
e, which turns a screw; the slide
f may be adjusted angularly by means of the slotted are and nut
g, and carries the rest, which is moved longitudinally by a screw and handle
h. The tool, being clamped in the holder, may be moved in a longitudinal, transverse, or circular direction, as required by the character of the work.
b is the
spherical slide-rest. This is provided with two additional slides for greater facility of adjusting the tool-holder to varying changes of position required in operating on curved and irregular forms.
c are tools used with the side-rest in hand and power lathes.
In
Fig. 5189, the point of the tool is set at any desired angle with the axis of the lathe by worm
c engaging a worm-wheel
b on the spindle
a 2 projecting from the lower part of the bed
B The bed
B and head
C turn together, carrying with them the tool-holder
F, which is advanced toward the work by a screw operated by the crank
j.
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Slide-rest. |
