for Polishing Glass Discs for the Production of Lenses for Optical Purposes.
Year: 1895

page_text: 'Date of Application (in United Kingdom), 30th Mar., 1895
Complete Specification Left, 28th Dec., 1895-Accepted, 28th Mar., 1896
PROVISIONAL SPECIFICATION.
Machine for Polishing Glass Discs for the Production of Lenses for
Optical Purposes.
We, The SOCIÉTÉ PARISIENNE DE VERRERIE OPTIQUE of 20 Rue Felicien
David, Paris in the Republic of France, do hereby declare the nature of this
invention to be as follows:-
:-
The object of this invention is to polish, and give to the glass discs in the
production of lenses, their final form, after they have been ground down to
the exact diameter required, and the desired form has been roughly given to the
lenses, and the invention consists in a special form of machine for carrying out this
object.
Hitherto this work has been done by hand with somewhat unsatisfactory results,
and it is with a view to produce more satisfactory results that the. present machine
has been devised.
In carrying out this invention, the discs of glass to be finished and polished are
stuck onto a rounded surface with pitch, or in any other convenient manner; this
rounded surface, whatever it may be, being carried on the end of a vertical shaft, to
which rotary motion is given in any convenient manner, the shaft also being provided
with means by which it can be raised and lowered as desired.
This rounded surface fits into a bowl carried by a vertical spindle, which is con-
nected by a universal joint to a box formed in one with a worm wheel, and carried
by a vertical shaft fixed to a slide attached to a slotted disc mounted on a vertical
axle, to which rotary motion is given in any convenient manner.
Mounted on the shaft, immediately below the worm wheel, is a bracket, in which
is mounted a worm which gears with the worm wheel, and is driven by an extensible
horizontal shaft connected by a universal joint with mitre gearing.
As the disc rotates, the worm wheel shaft is caused to describe a circle, by which
means an oscillatory motion is given to the concave rounded surface or bowl.
At the same time, rotary motion is given to the worm wheel shaft through the
worm, and thus a double motion is communicated to the bowl.
This bowl contains either damp emery powder or a polishing powder, according
to the nature of the operation it is desired to perform on the glass, whether a grinding
or a polishing operation.
Dated this 30th day of March 1895.
NEWTON & SON,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Machine for Polishing Glass Discs for the Production of Lenses for
Optical Purposes.
We, SOCIÉTÉ PARISIENNE DE VERRERIE OPTIQUE, of 20 Rue Felicien
David, Paris, in the Republic of France, 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 :-
The object of this invention is to polish, and give to the glass discs in the
production of lenses, their final form, after they have been ground down to
the exact diameter required, and the desired form has been roughly given to the
lenses, and the invention consists in a special form of machine for carrying out this
object.
Hitherto, this work has been done by hand, with somewhat unsatisfactory results,
and it is with a view to produce more satisfactory results that the present machine
has been devised.
In the accompanying drawings,
Fig. 1 is a sectional elevation of the machine, and
Fig. 2 a plan view.
Fig. 3 is a sectional elevation on
mechanism for working the tool; and
a larger scale, giving the details of the
Fig. 4 is a section on the line 1-2 of Fig. 3.
The glasses, which have been first roughly ground, are fixed, by the aid of pitch,
or any other suitable material, on the exterior surface of a cap A, fixed at the
extremity of a vertical shaft B. The cap A enters a hollow cap C, supported by a
shaft D. The relative forms to be given to the caps A and C, so that all the
glasses fixed on the cap A shall take the requisite curve, are calculated as we have
shown in our Application No. 6588, of even date herewith, relating to a rough
grinding machine.
The shaft B is furnished at its upper end with a loose pulley and a fast pulley b',
for the transmission of motion to the shaft B.
A grooved collar E, into which enters a fork F; permits, by the action of the
handle G, of raising the cap A out of the cap C.
It will be seen, therefore, that owing to this arrangement of this portion of the
apparatus, the cap A, during working, receives a continuous rotary movement, and
may be lifted out of the cap C, at pleasure.
Let us now examine the construction of the mechanism for operating the cap C.
The shaft D, which supports the cap C, enters a box H, to the sides of which it is
fixed by means of a gimbal I. Beneath the box H is mounted a toothed wheel J,
which engages with an endless screw K, keyed upon a horizontal axle L, the
extremity of which, L', is furnished with a universal joint M and a bevil wheel N.
The bevil wheel N is in contact with a second bevil wheel N', mounted on the
axle O. Between the part L' and the part L of the horizontal shaft, are arranged
four jointed links, P, P, P", P (Fig. 2), which thus permit of the shaft extending
or shortening of itself, according as the links p p approach or withdraw from the
links p p. Besides, by means of the joint M, the whole of the shaft L L' can
take any position with respect to the axle n of the friction wheel N, the shaft always
continuing to rotate upon itself, under the action of this wheel N, carried round by
the wheel N' keyed upon the shaft O.
The toothed wheel J, which is solid with the box H, and which gears with the
worm K, is mounted upon a shaft Q. The worm K is itself carried by two
supports KK", mounted on the shaft Q.
The shaft Q is fixed, at its lower end, upou a disc R, keyed to the end of a

page_text: shaft R', which may receive a rotary movement by means of the pulleys R". The
shaft Q is not fixed to the centre of the disc R, but at any point of its surface,
in such manner that, with respect to the shaft Q, the disc R shall be excentric
thereto.
Let us now examine the functions of the machine.
We commence by fixing upon the shaft B, raised by means of the handle G, a
cap A, upon the surface of which, have been arranged the glasses to which it is
desired to give a determined curve; we then lower (by releasing the handle F) this
cap A into the interior of the cap C, taking care to interpose between the two
surfaces some damp emery or English rouge, according as the glasses are being
operated on for the first or second time. This done, we set in motion, first the
shaft B, by means of the pullies 66'; second, the disc R, by means of the
pulleys R"; and third, the shaft L L', by means of the wheel N.
With respect.
to the cap A, these three rotary movements are reduced to one simple rotary
movement, transmitted to the cap A by the shaft B.
Let us see now with respect to the cap C, what is the movement resulting from
the two movements of rotation of the disc R and the horizontal shaft L L. We
may say at once, that the rotary movement transmitted by the shaft L L' will be
transferred to the cap C by a simple rotary movement.
In effect, if we suppose for a moment the shaft Q to be immovable, it will be seen
that by means of the worm K and the toothed wheel J, the box H, in one with the
wheel J, and the axle D of the cap, are actuated by a rotary movement about the
vertical axle X Y.
Let us now see what is the movement which the cap C takes from the excentric
disc R. This disc R, in turning, carries round the shaft Q, and this latter describes
the figure of a vertical cylinder, having for a radius the distance s s', which separates
the axis of the shaft Q from the axis of the shaft R', but the shaft D, being only
connected to the shaft Q by a gimbal, and being linked at its upper end to the cap C,
which rubs against the cap A, does not describe, like the shaft Q, the surface of a
cylinder, but a truncated cone instead.
The combination of these two rotary movements, one from the shaft L L', and
the other from the shaft R, will therefore give to the cap C an alternative movement
of oscillation, and a rotary movement around the axis X, Y, this rotary movement
around the axis X, Y, being, as is well understood, in a direction contrary to that
imparted to the cap A by the shaft B.
By means of the joint M and the jointed links P, P1, P1, P1, it will be seen
that the portion of the horizontal shaft L can follow the movements of the shaft Q,
whilst rotating and actuating the wheel J.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
--
The machine above described, which permits of the manufacture of optical glasses
which have been first edge-ground, and then rough ground, the said machine being
specially characterised by two caps A and C, of appropriate form, of which one, A,
carries upon its outer surface the glasses to be treated, and receives a rotary
movement, while the other, C, contains emery or English rouge, which rubs against
the exterior surface of the glasses carried by A, and receives, first, a rotary motion
upon itself, and, second, an alternative oscillating motion, as and for the purpose
set forth.
Dated this 18th day of December 1895.
NEWTON & SON,
Agents for the Applicants.