An Improved Machine for Bevelling Spectacle Glasses.
Year: 1899

page_text: Date of Application, 1st Aug., 1899
Complete Specification Left, 26th Sept., 1899-Accepted, 16th Dec., 1899
PROVISIONAL SPECIFICATION.
An Improved Machine for Bevelling Spectacle Glasses.
We, CARL HABILD, of 9, Grosse Miloerstrasse and MAX JUNGNICKEL, of 33,
Dunkerstrasse, both in Rathenow, in the Empire of Germany, Mechanician and
Optical Instrument Maker, do hereby declare the nature of this invention to be
as follows:-
The machines hitherto designed for bevelling spectacle glasses had the draw-
back that the glass had to be unfastened after one side of the bevel had been
ground. From this method inequalities in the bevelling easily arose, and hitherto
Develling machines have not been much adopted in practice.
By means of the present machine the glasses are bevelled without its being
necessary to unfasten them, and the two sides of the bevel are ground sym-
metrically.
The machine is essentially characterized by the glasses which are to be bevelled
being clamped between two clamp jaws by a frame provided with an oval
mechanism, which frame may be conveyed to the grind stone by means of a
carriage and ratchet gearing and may be adjusted on a pivot obliquely to the
grind stone in such a way that first one side and then the other side of the bevel
is ground.
The spectacle glass to be bevelled is placed between the two elastic clamp
jaws of two co-axially mounted shafts, one of which is constantly pressed by
a spring against the frame. By means of a hand lever the said shaft may be
pushed back against the action of the spring in order to allow of the bevelled
glass being taken out or exchanged for another. The two shafts are mounted
in a frame which is revolubly mounted by means of pins in another frame pivoted
on a vertical pin in order to be free to swing forwards and backwards, corresponding
to the elliptical shape of the glasses. In the second frame a driving shaft provided
with a belt pulley is mounted, on which shaft spur wheels are fixed which engage
in corresponding spur wheels on the clamp shafts.
The forward and backward swinging movement of the first frame is effected
by elliptical steel discs which are mounted on the clamp shafts and which bear
against steel plates on the second frame. Springs also provided with steel plates
bear against the rear side of these steel discs, which springs constantly press
the steel discs against the second frame. On the rotation of the shaft in con-
sequence of this arrangement the frame with the clamp shafts and the glass
gripped between the same are set in a reciprocating movement on the pivots or
pins corresponding to the form of the steel discs. If the second frame be so turned
on its vertical pin that it is obliquely directed to the grind stone on one side or
the other, and if then the carriage carrying the said frame be pushed forward
against the grind stone, one side of the bevel will be ground to correspond precisely
with the form of the steel discs. After finishing one side of the bevel, the said
frame is placed obliquely towards the opposite side in order to also grind and
finish the other side of the bevel.
In order to fix the said frame in its end positions, it is provided with a ston

page_text: which bears against one or the other end of a notch or recess in the carriage.
In the end positions in question, the frame is then fixed by means of a set screw.
The automatic displacement of the carriage carrying the frame is effected by
means of a screwed spindle located in the carriage guide, which spindle is
provided at its end with a ratchet wheel. A pawl engages in this wheel,
which is operated by means of a suitable crank gearing from the shaft. The
end position of the carriage is limited by an adjustable stop. The carriage guide
may be adjustable by means of a screwed spindle in a cross piece in order to allow
of the frame with the glass which is to be bevelled being also adjusted diagonally
to the grind stone. By this means the position of the ratchet wheel relative
to the pawl is altered, and the latter may be provided with several teeth of different
lengths, one or other of which will come into action according to the position of
the ratchet wheel. The ratchet wheel may be operated in any other suitable
manner.
The shaft may be driven by means of a band passed over a pulley and driven
from another shaft which is rotated from the main shaft. Another shaft is driven
from the said shaft, and its movement is communicated to the vertical shaft by
means of a worm gear. At the upper end of the same, an adjustable eccentric is
fixed, which acts on the two discs of the grindstone shaft, and thereby slowly moves
the grindstone to and fro.
Instead of arranging the pivot for the clamp frame on the lower end of the same,
so that the frame may be displaced relative to the driving shaft the latter may also
be preferably utilized as pivot for the frame, as in this case the spur wheels do
not alter their engagement.
L
1000
W. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.
44
We, CARL HABILD, of 9, Grosse Miloerstrasse and MAX JUNGNICKEL, of 33,
Dunkerstrasse, both in Rathenow, in the Empire of Germany, Mechanician and
Optical Instrument Maker, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to machines adapted for grinding facets on glasses for
optical purposes, spectacles and the like and is intended to obviate the difficulties
presented by the machines heretofore in use for that purpose in which it was neces-
sary to remove the glass from its support after the grinding of one side of the facet
and then adjust it again for the grinding of the other side which gave rise to
frequent and very annoying irregularities in the configuration of the facets.
Heretofore it has been impossible to adapt faceting machines to the shaping of
optical glasses of oval form and with a wedge shaped facet.
By the invention forming the subject of this application, facets may be ground
upon such glasses without the necessity of removing the glass for the grinding
of the other side of the facet thus securing perfect symmetry of both sides of the
facet.
The machine is especially distinguished by the use of a frame having suitable
clamps for the attachment of the glasses to be worked and which receives an
oscillating movement in accordance with the oval form of the glasses, the distance
of the frame from the grinding stone being adjusted by means of a carriage

page_text: and suitable gearing while it is further capable of adjustment in a direction
inclined towards the position of the grind stone by means of a turn table so as
to allow of subjecting first one and then the other side of the facet to the grinding
action.
Our invention is illustrated in the accompanying drawing which represents a
machine embodying our invention. Fig. 1 is a vertical longitudinal section of
the machine. Fig. 2 is a front view of the machine. Fig. 3 is a longitudinal
section of the frame for fastening the glasses. Fig. 4 is a cross section of the
said frame. Fig. 5 is a plan view illustrating the different positions of the
fastening frame with relation to the grind stone. Fig. 6 is a detail of the machine.
a is the glass to be operated upon and which is fastened between the jaws of the
clamp, b, b, said jaws being attached to the shafts B, B₁ and which are placed so
as to be forming one straight line with their respective axes. R¹, R are springs
which serve to tightly press the two jaws against each other. S is a hand lever by
means of which the shaft B₁ may be separated from the shaft B against the
tension of its spring R², in order to remove the glass or exchange it against
another. The shafts are journaled in the frame C which is pivoted at C¹ to the
frame H so as to be able to reciprocate in accordance with the oval shape of the
glass, the frame H being made to turn upon a horizontal plate J. F is the driving
shaft journaled upon the frame H and receiving its motion from the pulley G and
to which gear wheels E E¹ are keyed engaging with the toothed wheels D D' upon
the shafts B, B¹.
Oval shaped discs R of steel or other suitable material are attached to the shafts
B, B adjacent to the plates T of steel or other suitable material fastened to the
frame H. Springs V having steel plates U serve to press the discs R against the
frame H. Upon rotating the shaft F, this arrangement causes a rocking motion
of the frame C with its shafts B, B1 thereby also rocking the glass a fastened
between the jaws b, b¹ in accordance with the configuration of the discs R. Upon
now turning frame H, as represented in Fig. 5, upon its turn table J so as to assume
an inclined position with relation to the grinding stone Q and upon now advancing
the carriage K upon which the turn table J is fastened in the direction of the
grind stone, one side of the facet will be ground exactly corresponding to the
form of the discs R. When the grinding of one side of the facet has been
finished, the frame H is turned so as to form an angle in the reverse direction
and the other side of the facet ground as usually.
A spring H' is fastened to the frame H, a pin H2 being further provided and
fitting into corresponding openings of the sector J¹ fastened to the edge of the
table J, so as to allow an exact adjustment of the frame H in its respective
positions.
The forward movement of the carriage K bearing the frame H is effected by
means of a screw L, rotating in the guide way 0 and bearing at its end the worm
wheel M which engages with the endless screw Y moved by the shaft X by means
of string pulleys or other suitable gearing. The forward movement of the
carriage K is limited by the adjustable stop N. In the arrangement represented
in the drawing, the guide way O is also adjustable in a transverse direction by
means of the screw W fixed upon the transverse carriage P so as to be able
to also adjust the glass in a transverse direction with relation to the grind stone.
Motion is imparted to the driving shaft F from the pulley G rotated by a string
or belt from the shaft which in its turn receives its motion from the main driving
shaft u.
Shaft imparts motion to the shaft w which by means of a screw and
worm wheel rotates shaft X. The upper end of said shaft X is provided with an
adjustable cam disc Z (Fig. 6) which actuates the two discs of the shaft.
of the grind stone and thereby slowly reciprocates the grind stone.
Instead of pivoting the frame C to the frame H at their lower ends, it will be
found convenient for some purposes to use the driving shaft F as a pivot for the
frame C, nothing being changed as regards the engagement of the gear
wheels E, D, E¹, D¹.

page_text: The mode of operation of the machine is as follows:-The optical glass being
securely fastened between the jaws b, b', flat spring H' is slightly raised and frame
His then shifted upon its turn table until the pin H2 exactly registers with the
desired point of the scale attached to the sector J-say 30°. The spring H¹ being
then released its tension will be sufficient to securely hold the frame H during the
process of grinding. When the grinding of one side of the facet is finished, the
glass is shifted in the same manner to the opposite direction without difficulty.
If desired, it is obvious that a similar scale can be provided at the opposite end
of the turn table J which of course also necessitates the attachment of a second flat
spring Hat the opposite end of the frame H.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is :-
1. In a machine for grinding facets to optical glasses having a frame for the
attachment of the glass,means for imparting a rocking motion to said frame, a turn
table for the rotation of said frame and a carriage connected to said turn table and
allowing of changing the position of the frame in relation to the grind stone
substantially as described.
2. In a machine for grinding facets to optical glasses, having a frame for the
attachment of the glass, means for imparting a rocking motion to said frame, a
turn table for the rotation of said frame and a carriage connected to said turn
table, rotatable oval discs attached to the frame and imparting an oscillating
movement thereto upon their rotation substantially as described.
3. In a machine for grinding facets to optical glasses, having a frame for the
attachment of the glass, means for imparting a rocking motion to said frame, a
rotary frame pivotically connected thereto and means for adjusting the relative
position of said rotary frame substantially as described.
4. In a machine for grinding facets to optical glasses, having a frame for the
attachment of the glass, means for imparting a rocking motion to said frame, a
turn table for the rotation of said frame, a carriage connected to said turn table, a
cam disc (Z) to impart a reciprocating movement to the grind stone, substantially as
described.
5. In a machine for grinding facets to optical glasses, having a frame for the
attachment of the glass, means for imparting a rocking motion to said frame, a
turn table for the rotation of said frame, a carriage connected to said turn table
and a feed screw attached to said carriage for adjusting the frame longitudinally,
substantially as described.
Dated this 19th day of September 1899