IMPROVED MACHINERY FOR CUTTING AND POLISHING GLASS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Alfred Vincent Newton, at the Office
of the Commissioners of Patents on the 5th March 1877. A communication
from abroad by Messieurs Ungerer and Griessmayer, of Pforzheim, in the
Empire of Germany.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. "IMPROVED MACHINERY FOR
CUTTING AND POLISHING GLASS." A communication from abroad by Messieurs
Ungerer and Griessmayer, of Pforzheim, in the Empire of Germany.
The object of this Invention is to effect in an economical manner the cutting and
polishing of table and other glass, and to prevent injury to the health of the work-
men employed from the constant immersion of their hands in cold water.
For grinding the glass (a tumbler for example) to pattern a suitably prepared
disc wheel is used. This grinding wheel is mounted on a horizontal spindle, which
turns in bearings carried by a bench or table. The spindle is fitted with driving
pullies for receiving a driving band from any prime mover. In front of this grind-
ing wheel the glass to be ground is set, it being carried by a chuck of peculiar
construction. This chuck is mounted on a slide which moves in V blocks formed on
the face of a swivel plate, which plate is capable of being fixed in any desired position
on a bare plate that is clamped to the bench or table. This bench or table is slotted
in a line parallel with the spindle of the grinding wheel, and through it projects a
screw from the base plate, which screw receives a nut that serves to clamp the plate
to the bench in its adjusted position. The slide is fitted with a traversing screw
which passes through a threaded lug on the swivel plate, and it is furnished with a
winch handle for giving it rotary motion. This screw has a quick left-handed
thread, to enable the slide to move the work carried by the chuck quickly up to the
grinding wheel.
The chuck for holding the work consists of two discs, from which project stud axles
that have their bearings in the standards of the slide, one of which standards is
made adjustable to suit different sizes of work.
The discs are furnished on their inner faces with pins to receive blocks of cork,
between which the glass to be ground is firmly held; the bearing surfaces of these
blocks, may be coned or otherwise shaped to suit the form of the article under
treatment, and ensure its being mounted concentrically in the chuck.
The stud axle of one of the discs receives a dividing wheel, which is held in place by

page_text: a nut screwing on to the end of the stud axle. When the chuck is placed in position,
the adjustable standard is by means of a traversing screw advanced until the desired
endway pressure is put upon the glass (through the medium of the blocks of cork)
to ensure its being firmly held while the grinding takes place.
Mounted loosely on the spindle of the left-handed traversing screw, which
advances the slide to and extracts it from the grinding wheel, is a weighted arm,
which is free to move over a slotted segment plate made fast to the swivel plate.
This slotted segment plate is intended to receive adjustable stops, between which the
weighted arm is free to move. Pivotted to the weighted arm is a pawle which
drops into the teeth of a ratchet wheel made fast to the traversing screw. As this
screw is rotated by its winch handle to move the work up to the grinding wheel,
the pawle will slip over the ratchet wheel. When the work has been brought into
contact with the grinding wheel, the weighted arm is lifted to its highest position,
and rotary motion being then given to the grinding wheel, the cutting of the glass
will proceed. The weighted arm now comes into action, and through its pawle gives
a slow axial motion to the traversing screw, which thereby advances the work at the
rate at which the cutting action proceeds. When a sufficient depth of cut has been
made the descent of the weighted arm will have been arrested by the adjustable
stop of the segment plate. The attendant has then to reverse the traversing screw
to retract the work from the grinding wheel, and by means of the dividing wheel
and a retaining catch with which it is provided, he effects the required axial adjust-
ment of the work. The slide is then again moved forward, and the weighted arm
being returned to its highest position, the cutting action proceeds as before.
A similar arrangement of mechanism is used for polishing the glass after.
grinding, a suitable polishing wheel being employed in place of the grinding
wheel.