Improvements in Machines suitable for Grinding Oval Glass and the like.
Year: 1889

page_text: Date of Application, 29th Apr., 1889
Complete Specification Left, 28th Nov., 1889-Accepted, 22nd Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in Machines suitable for Grinding Oval Glass
and the like.
I, ROBERT FRIEDEL of 10 Squefelderstrasse, Stuttgart, in the Empire of Germany,
Manufacturer, do hereby declare the nature of my invention to be as follows :-
This invention relates to lathes or machines for grinding oval glass, the improved
machine differs mainly from those heretofore known in that grinding disc is mounted
on a swinging frame to compensate for the grinding and that the rest bed for the
object to be ground is provided only with the positive motions necessary for the oval
grinding.
On a vertical pillar or equivalent supporting frame are two vertical sliding brackets
with screw adjustment. One of said brackets carries a horizontally sliding
bracket with screw adjustment this latter bracket carrying pivoted to its outer end
the swinging frame which carries the shaft of the grinding disc and the necessary belt
pulleys etc. for revolving the grinding disc. The other bracket carries cast or fixed
therewith an inclined rectangular frame on which the oval chuck hereinafter
described is supported. The lowest point of the disc is the grinding disc. The outer
end of the swinging frame is partially supported by a standard pivoted by an adjust-
able pivot to the end of a balance lever pivoted to the frame of the machine and
carrying an adjustable counterweight so that the pressure of the grinding disc due to
the difference of weight may be adjusted.
A suitable stop may be arranged to prevent further fall of the swinging frame when
the amount of grinding desired is completed.
The oval chuck comprises mainly a rotary spindle revolved by worm and pinion in
a stationary position. This spindle revolves a plate to which a positive back and forth
horizontal movement over the end of the spindle is given by suitable adjustable gear.
On the plate is a conical pin or equivalent to receive a species of clamp or tongues
which embraces the article to be ground and holds it in position over the plate to be
revolved with the oval motion due to the rotary movement of the spindle and the back
and forth movement combined therewith. The spindle etc. being inclined, the emery
and water etc. used in grinding flow off the objects ground more easily.
Dated this 29th day of Auril 1889
COMPLETE SPECIFICATION.
Improvements in Machines suitable for Grinding Oval Glass
and the like.
I ROBERT FRIEDEL of 10 Seuefelderstrasse, Stuttgart in the Empire of Germany
Manufacturer do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
-
This invention relates to machines for grinding glass etc. to an oval shape and
consists in certain combinations of parts as hereinafter described and claimed.
The improved machine differs mainly from those heretofore known that the grinding
disc is mounted on a swinging frame to compensate for the grinding and that the
rest bed for the object to be ground is provided only with the positive motions necessary
for the oval grinding.

page_text: Reference being made to the annexed drawing
Fig. 1 is a front elevation of the improved machine.
Fig. 2 is a side elevation thereof.
Fig. 2b is a perspective view of the machine.
Fig. 3 is a plan of the swing frame of the grinding disc.
Fig. 4 is a sectional view of the oval chuck.
Figs. 5 to 15 are detail views of the chuck.
On the upper part of the pillar or frame F are guided the two slides S and S¹ on
opposite sides and capable of being adjusted in a vertical direction by the screws V
and V. The slide S carries at its upper end the table t cast obliquely therewith and
provided with the socket B for the oval chuck O hereinafter described. On the slide S¹
is the bracket T forked at the top and adjustable horizontally on the slide S¹ by the
screw V2. This bracket T serves for supporting the swing frame G carrying the
grinding disc S°. On the shaft W journalled in the fork of the bracket T are the two
three-grade pulleys K and K', two driving belt pulleys and 2 one of which is fast
and the other one loose, and the swing frame Ġ. The latter which can swing upon
the shaft W carries at its front ends two adjustable wooden bearings between which
lies the shaft W provided with points and carrying the grade pulley K² which
corresponds with the pulley K on the shaft W and also the grinding disc S°. The
lowest point of the disc So is the grinding point and lies in a vertical plane with the
centre of the column F. On the side of the column F' of the machine is arranged
a lever device. The lever H' turns on a pivot P which is fixed to the column F. The
rod H supporting the outer end of the swing frame G is straight below and provided
with round holes and connected with the lever H by the pin Q. The lever H carries
in front the sliding weight G¹. The whole lever contrivance keeps the swing frame G
in a horizontally balanced position. By suitably moving the weight G the pressure
with which the glass is ground can be regulated. On the left of the machine is bolted
or otherwise fastened an angle bracket which serves for supporting the clamp E of
the oval chuck. The angle bracket N'arranged on the front of the machine carries
at its forward end a vertical set screw M in the same vertical plane with the
lever H¹.
The driving of the shaft W is done by a belt connecting the shafting to the fast
pulley . An ordinary disengaging fork may be employed to move the belt R from
the fast pulley to the loose pulley and thus the working of the machine can be
stopped at once. The driving of the grinding disc and of the oval chuck is performed
from the shaft W.
For the first the grade pulley K on the shaft W is connected by a belt with the
pulley K² on the shaft W₁, for the other the grade pulley K¹ on the shaft W is
geared by belt to the pulley K³ on the shaft W2
The raising and lowering device of the slide S¹ with the bracket T, the horizontal
adjustinent of the bracket T¹ the vertical adjustment of the bracket S carrying the
oval chuck render possible, first that in any case the grinding point may be at the
lowest point of the grinding disc, and second, glass discs can be bevelled more or
less obliquely and to greater or less width.
The improved machine has a further advantage that ovals of different sizes and of
different proportions of axes can be made by reason of the construction of the oval
chuck.
The contrivance is intended. for supplying sand or emery and water and the
position of the glass plate being always oblique, in grinding, produces and, accelerates
a natural escape of the water and of the sand.
During the grinding, the grinding disc is lowered gradually and thereby effects a
slow raising of the lever H. When the latter has arrived against the screw M the
glass has been completely ground.
By pressing down the lever H¹ until the projecting spring F1 stops it, the swing
frame G is raised so that the clamp E Fig. 4 with the glass plate can be easily
removed or inserted.

page_text: 6. The combination of the parallel clamping device E, the swing frame G carrying
the grinding disc, the lever system H H for regulating the pressure of said disc,
the brackets S S T T constructed substantially as described for permitting the
adjustment of the parts, the chuck and the adjusting screw M for limiting the
grinding, the whole substantially as set forth.
Dated this 28th day of November 1889.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.