Year: 1886

page_text: Date of Application, 24th Sept., 1886.
Complete Left, 28th Dec., 1886.
Complete Accepted, 12th July, 1887.
We EDWARD HENRY PEARCE of Bridge Street Broad Street Birmingham in the
County of Warwick Manufacturer and HYPPOLITE BESSON of 46 Bonner Road
Bethnal Green in the County of Middlesex Mechanical Engineer do hereby declare
the nature of our said invention to be as follows:-
Our invention has for its object improvements in machinery for working glass by
which we are able to secure in position various shaped pieces of glass such for instance
as convex, concave or flat or hollow pieces without undue or unequal pressure being
exerted thereon either from variations in the thickness of the glass or from unequal
surfaces thereon which would tend under ordinary conditions to produce distortions
or strain. The method of holding various shapes varies somewhat in details for
instance the apparatus or tool or part of the machine for holding a large sheet of
plate glass will be very different from the one for holding a small spectacle glass or
telescope lens and the method of holding small and large lens may not always be
alike the treatment varying according to the size shape strength and nature of the
surface or surfaces thereof. Machinery for working glass has been the subject of
previous patents No. 7461 of 9th May 1884 and No. 8310 of 9th July 1885 in which
pieces of glass are held by a vacuum or a partial vacuum against the grinding
smoothing and polishing surfaces while they are shaped. This invention more fully
developes parts of these patents and introduces also new modes of dealing therewith.
In applying a vacuum or partial vacuum to the back of the glass for the purpose
of holding it by atmospheric pressure it will be obvious that the glass can be fixed
sufficiently for some purposes by distributing India Rubber cushions on the chuck
according to Specification No. 8310 A.D. 1885 before mentioned.
But if the glass
be-for example-a shallow convex, or concave parts thereof may be so thin after

page_text: grinding as to yield more or less where unsupported by the india rubber cushions to
the atmospheric or tool pressure during its developement in working. Now any
spring or unnatural alteration in the form of the glass while being ground amounts
to a fault or inaccuracy when taken out of the grinding machine but we avoid such
defects in the following manner :-In holding the glass to be ground we place the
back against india rubber rings or cushions fixed on a face plate or holder having
previously introduced into the vacuum chamber the necessary quantity of water or
other fluid.
We then open a tap between the back of the glass and the vacuum chamber which
places them in communication and exhausts the air through a tube which is contained
within the spindle described in Specification before mentioned viz.:-No. 8310
A.D. 1885.
The water or other fluid in the vacuum chamber is thus allowed to fall through
annular space between the said tube and inner circumference of the spindle to the
back of the glass to form a liquid packing or cushion i.e. the vacuum acts either
.constantly upon or through the water or the tap may be turned off thus separating
the communication which may be occassionally reopened if required to refresh the
vacuum.
The back of the glass is therefore practically solid while the grinding goes on.
Several india rubber rings may be used in making the joint when found desirable.
In holding large pieces of plate or other glass we provide the frame with longi-
tudinal or other cushions of india rubber so that the back of the glass is protected.
from the sand or other material used in the process of working by the edges resting
on these said cushions. We hinge the frame vertically or nearly so upon one or
more joints or hinges with an arm communicating with a pivoted rod carrying a
spring and tightening nut for giving the proper inclination to the frame for bringing
the glass in contact with the grinding smoothing and polishing surfaces the spring
and nut being so adjusted as to give the necessary pressure while the spring permits.
measured freedom of action in compensating for grit or other inequalities or variations
between the edge of the glass and the grinding medium. To prevent spring in
securing the plate of glass upon the frame we supply the frame with any suitable
number of suction surfaces capable of easy and quickly adaptable_movements in
being pressed forward from the back of the frame against the glass. Each adjustable
surfaces has its separate india rubber ring or rings and a suitable regulating screw
for securing it when fixed at the back of the glass against the bedding rubbers and
outer bedding rings. A flexible or other pipe or passage communicates with each of
the several surfaces and, with a common vacuum chamber by a cock or cocks and in
the case of large sheets of glass we prefer to use a large number of small surfaces
without the water packing though the water packing may be used.
We find it well to use the compensating spring action and arm as above described
in connection with the oscillating frame e shown upon the drawing sheet 1. Figure 1.
of Specification 8310 A.D. 1885 so as to ease the dead pressure of the edge of the
glass's on the grinding surface n.
In grinding a number of say spectacle glasses at one time we form on a section
of a sphere a number of flat, surfaces sufficiently large to make a suitable bed for
each price.
Each surface has its india rubber joints piece and its passage communicating with
the vacuum chamber either by a flexible tube or otherwise. The number of pieces of
glass to be ground at one operation will of course depend upon their size and the
radius of the curve required. The grinder is dished to the proper curve to receive-
the holder and this is moved on the universal joint principle by well known means
under constantly varying conditions or in a constantly varying seat or surface. It is
obvious that the glasses to be ground may be attached to either a convex or concave
surface the grinder corresponding and that either may be at the top or bottom. All
the processes for finishing the glasses may be performed without the removal of the
glasses from the holder.
In producing a convex surface from flat glass or in finishing such from a piece cast

page_text: roughly to shape we secure the piece to be ground as before described by vacuum,
either with or without fluid packing upon the extremity of a pivoted spindle over a
horizontal grinding mill.
- This spindle not only rotates but is moved upon its pivot or knuckle joint so as to
gradually compass the whole surface thereof on the grinding medium. The distance
from the centre of the pivot or knuckle or other joint to the outer surface of the
block so ground will obviovsly be the radius of the curve of the glass so ground. The
grinding surface may of course be either flat or partly formed so as to assist in
accurately developing the-curves. required and the positions of the arın or grinder
may be exchanged or altered from the horizontal so long as the necessary pivoted
action of either part is maintained in its relation to the curved surfaces. Several of
these may be used on one grinder at the same time.
GEORGE BARKER,
77, Colmore Row, Birmingham,
:
Agent for Applicants.

page_text: We EDWARD HENRY PEARCE of Bridge Street Broad Street Birmingham in the
County of Warwick Manufacturer and HYPPOLITE BESSON of 46 Bonner Road
Bethnal Green in the County of Middlesex Mechanical Engineer do hereby declare
the nature of our said invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:
Our invention has for its objoct improvements in machinery for working glass by
which we are able to secure in position various shaped pieces, of glass such for instance
as convex, concave or flat or hollow pieces without undue or unequal pressure being
exerted thereon either from variation in the thickness of the glass or from unequal
surfaces thereon which would tend under ordinary conditions to produce distortions or
strain. The method of holding various shapes varies somewhat in details for instance
the apparatus or tool or part of the machine for holding a large sheet of plate glass
will be very different from the one for holding a small spectacle glass or telescope
lens and the method of holding small and large lens may not always be alike, the
treatment varying according to the size shape strength and nature of the surface or
surfaces thereof. Machinery for working glass has been the subject of previous
patents No. 7461 of 9th May 1884 and No. 5310 of 9th July 1885 in which pieces of
glass are held by a vacuum or a partial vacuum against the grinding smoothing and
polishing surfaces while they are shaped. This invention more fully developes parts
of these and introduces also new modes of dealing therewith.
In applying a vacuum or partial vacuum. to the back of the glass for the purpose of
holding it by atmospheric pressure it will be obvious that the glass can be fixed
sufficiently for some purposes by distributing India Rubber cushions on the chuck
according to Specification No. 8310 A.D. 1885, before mentioned. But if the glass
be-for example-a shallow convex or concave parts thereof may be so weakened
after grinding as to yield more or less where unsupported by the India Rubber
cushions to the atmospheric or tool pressure during its developement in working.
Now any spring or unnatural alteration in the form of the glass while being ground
amounts to a fault or inaccuracy when taken out of the grinding machine but we
avoid such defects in the following manner :-In holding the glass to be ground we
place the back against india rubber rings or cushions fixed on a face plate or holder
having previously introduced into the vacuum chamber the necessary quantity of
water or other fluid.
We then open a tap between the back of the glass and the vacuum chamber which
places them in communication and exhausts the air through a tube which is contained
within the spindle described in Specification before mentioned viz. No. 8310
A.D. 1885. The water or other fluid in the vacuum chamber is thus allowed to fall
through annular space between the said tube and inner circumference of the spindle
to the back of the glass to form a liquid packing cushion, i.e. the vacuum acts either
constantly upon or through the water or the tap may be turned off thus separating

page_text: the communication which may be occassionally reopened if required to refresh the
vacuum.
The back of the glass is therefore practically solid while the grinding goes on:..
Several india rubber rings may be used in making the joint when found desirable.
In holding large pieces of plate or other glass we provide the frame with
longitudinal or other cushions of india rubber so that the back of the glass is pro-
tected from the sand or other material used in the process of working by the edges
resting on these said cushions. We hinge the frame vertically or nearly so upon one
or more joints or hinges with an arm communicating with a pivoted rod carrying a
spring and tightening nut for giving the proper inclination to the frame for bringing
the glass in contact with the grinding smoothing and polishing surfaces the spring
and nut being so adjusted as to give the necessary pressure while the spring permits
measured freedom of action in compensating for grit or other inequalities or variations
between the edge of the glass and the grinding medium.
To prevent spring in securing the plate of glass upon the frame we supply the:
frame with any suitable number of suction surfaces capable of easy and quickly
adaptable movements in being pressed forward from the back of the frame against
the glass. Each adjustable surface has its separate India rubber ring or rings and a-
suitable regulating screw for securing it when fixed at the back of the glass against
the bedding rubbers and outer bedding rings. A flexible or other pipe or passage.
communicates with each of the several surfaces and with a common vacuum chamber.
by a cock or cocks and in the case of large sheets of glass we prefer to use a large.
number of small surfaces without the water packing though the water packing may
be used.
We find it well to use the compensating action and arms as above described in
connection with the oscillating frame c shown upon the drawing Sheet 1 Figure 1. of
Specification 8310 A.D. 1885 so as to ease the dead pressure of the edge of the:
glass s on the grinding surface r.
In grinding a number of say spectacle glasses at one time we form on a segment
or part of a sphere a number of flat surfaces sufficiently large to make a suitable bed.
for each piece.
Each surface has its india rubber joint piece and its passage communicating with.
the vacuum chamber then by a flexible tube or otherwise. The number of pieces of
glass to be ground at one operation will of course depend upon their size and radius
of the curve required. The grinder is dished to the proper curve to receive the
holder and this is moved on the universal joint principle by well known means under
constantly varying conditions or in a constantly varying seat or surface. It is obvious
that the glasses to be ground may be attached to either a convex or concave surface.
the grinder corresponding and that either may be at the top or bottom. All the
processes for finishing the glasses may be performed without the removal of the
glasses from the holder.
In producing a convex surface from flat glass or in finishing each from a piece cast
roughly to shape we secure the piece to be ground as before described by vacuum-
either with or without fluid packing upon the extremity of a pivoted spindle over a
horizontal grinding mill.
This spindle not only rotates but is moved upon its pivot or knuckle joint so as, to
gradually compass the whole surface thereof on the grinding medium. The distance
from the centre of the pivot or knuckle or other joint to the outer surface of the
block so ground will obviously be the radius of the curve of the glass so ground.
The grinding surface may of course be either flat or partly formed so as to assist in
accurately developing the curves required and the positions of the arm or grinder may
be exchanged or altered from the horizontal so long as the necessary pivoted action of:
either part is maintained in its relation to the curved surfaces.
Several of these may be used on one grinder at the same time.
This invention is in particular a further developement of Patent No. 8310.
A.D. 1885 which is to hold the glass continuously on the same chuck without
removal while passing through the processes of roughing, smoothing and polishing

page_text: and this continuous holding in one position is essential to keep the surface made by
the first process exactly true so as to be presented to the next process in exactly the
same position upon the surface.
Glasses held by the pressure of the Atmosphere on india rubber packing leaving a
hollow space between the glass and the chuck are generally strained; and that hollow
part which does not support the glass has the effect of allowing the pressure to bend
the glass. So long as glasses are to be bevelled only this method of holding the glass
is quite sufficient but if the glass is to be used for optical purposes and requires to be
curved or hollowed to a given focus such a glass while held by this method would be
worthless as the rays to be reflected or refracted would be distorted and to avoid this
we hold the glass by the atmospheric pressure on a backing, packing or cushion of
water which we form in various ways.
In order that our invention may be clearly understood and more easily carried into
practical effect we have appended hereunto three sheets of drawings upon which
several examples of various applications are shown as applied to several purposes and
from which practical men will be able to further apply the said principle.
Figure, 1, shows the apparatus patented in 1885 No. 8310 to hold glass by vacuum
while grinding with a water backing or cushion.
His the vacuum chamber, B, B the spindle, c the chuck, Z, 2 cocks to restore the
vacuum, Z is a five way cock to restore vacuum and water in the space between the
glass and chuck. Z is a small cock for water to enter the vacuum chamber H.
Zis to admit water at the back of the glass if water is taken outside the chamber
direct to the space. , is a tube fitted nearly from the top of the chamber H to the
bottom of the hollow in spindle and connected to one edge of the chuck at ¹ by a
channel made at the lower end of the spindle and through the cock 7, w, w, w is the
main hollow made in the spindle to receive the water in which the tuber is fitted and
connects to the centre of the chuck by a channel through the lower end of spindle
and cock Z¹.
Figure, 2. shows the plan of a chuck with india rubber packing.
india rubber
packing. water hole from the vacuum chamber, w₁ water holes from cock Z fitted
on top of chuck. is a hole by which the vacuum is maintained connected with the
vacuum. chamber.
Figure, 3. shows a chuck to hold a double convex glass on a water backing. S is
the glass, the India rubber packing. W water cushion. Z cock by which water
is entered. hole by which the vacuum is maintained in space.
Figure 4, shows a-chuck to hold a speculum or concave glass on a water backing
S: S. is the glass, v, e, the india rubber packing. W water cushion. Z cock by
which water is entered. the vacuum hole.
Figures 5, 6, 7 and 8 are different views of a machine to make bevels on large
plate glass, T is the bed, T¹ is a carriage with a to and fro movement like a planing
machine T2, T3, are two standards carrying small vertical slide. T, T are open
mouthed bearings formed on slide T to receive pivots P¹ of the plate P. P is a plate
or frame pivoted on pin P1, P1. R is an angular regulating lever mounted on
fulcrum R and connected to the frame P through the bush bar and spring" and
wheel. The plate P has several longitudinal cushion pieces v, v, v made of india
rubber for the plate of glass to lay upon the bottom piece is used to lay the edges
of the glass upon and to keep the sand from going to the back.
c, c, c, c are small
suction plates fitted in apertures in the frame P and connected to the vacuum
chamber H by tubes i, 1, 1, and cocks Z, Z, Z, Z. Several vacuum chamber
may be used if necessary. The glass S is brought against the cushion u, v, v by
screwing the wing nut 62 on the spring & this spring b³ is to regulate the tension
or pressure of the screwing. g is the grinder mounted on a nearly horizontal
spindle.
Figure 8. is an enlarged view in section of a suction plate. S is the glass, vis a
small packing on suction plate.. P the plate, the stem, 6ª the spring, the wing 5
nut: the three way cock the india rubber tube.
Figures 9 and 10 are two views showing the plate with an arrangement to bevel

page_text: several glasses completely without taking them off the suction plate or chuck. In
this case each suction plate or chuck has an independant chamber Hand the apparatus
is fixed on slot o.
It is composed of chamber H cock Z' stem or journal 0. Two guide plates o, o²;
chuck c one of the guide plates of acts as a former on guide bar o². The guide bar
has adjusting screw o³, 93 and travels in the oblong sleeve o*.
Figure 11. shows a part section of a machine to grind small optical glasses held
by atmopheric pressure. B' is the spindle running in bearings B and B carrying
the vacuum chamber H and chuck C with glasses SS receiving rotation by pulley H
formed on chamber H, is the cup or grinding shell receiving sand through gl
operated by stem g. 1, 1, I are the sand holes 1,,, are holes to allow atmospheric
pressure on glasses, t, t, pipes connecting glasses S, S to chamber H by cocks Z, Z',
and ring pipe t and radial pipes J is a vertical hollow spindle receiving
rotation through a pulley and strap or bevel gear and having at its upper end formed
with a conical funnel to receive sand delivering it by hole at its lower end.
The shell or cup g' is operated by adjustable crank J and oscillating sleeve J³..
Figure 12, shows a part section of a machine having the cup working underneath
instead of the chuck. is the cup, the chuck receiving angular rotation by
shaft J through J and J and t¹, t' are the ring pipes and Z', Z', the cocks.
Figure. 13. shows a part section of how the glasses when ground on one side as
shown in Figure 11 are fixed on another chuck with the hollowed suction places.
Figures 14 and 15 shew apparatus to rough single optical convex with flat or
concave grinder, B is the spindle carrying chuck C and chamber H. Z and Z are.
cocks to connect or disconnect the vacuum, W the water cushion, a² the vacuum
channel the India rubber packing. Da frame, Dadjustable collar. D², D³ bevil
gear. D³ feather running in feather groove made on spindle B. d pivot or
fulcrum on which frame D swings by weights suspended on cord q Figure 15, d¹ d².
adjustable bearings sliding on bars, d, d, fixed on carriage A. A carriage travelling
on rail E, E by wheels E, E.
The rails E, E, are supported by brackets e, e. The adjustment of radius is made
through cord U fitted on pulley U which operates the screw K, K equally by
gearing K, K and K2, K².
Figures 16 and 17 show a modification of the above to grind smooth and polish
large concave and convex glass-or any other curve by aid of the curtailed radius or
5. template bars F F. B is the spindle carrying the chuck C and chamber H and
supported by bearings and and anti-friction box f, F¹ the frame F2 and F3
wheels travelling on bars F, F. F template bars supported by brackets N and
anjusted by sliding block N' and screw N. y and yl spindles of wheels, Y clutches,
y bevil gear gearing the worm screw spindle Y' and worm wheel Y¹.
Now referring again to Figure 1 which shews apparatus to bevel the surface of glass
having one form of our arrangement to make the water backing which consists of a
chuck e having joint pieces or ring v of thin India Rubber which leaves a shallow.
recess or space between the glass and the chuck. This chuck is fitted to the hollow
spindle B, B at one end and at the other end is the hollow vacuum chamber H. A
cock Z is fitted above the chamber H and a five way cock on the spindle above the
chuck. In the hollow of the spindle leading up to the chamber a tube a is fitted and
connected to the chuck at ¹ by a channel made through the five way cock Z¹ and the
lower end of spindle.
The other part of the hollow of the spindle is also connected to the chuck at w by
a similar but larger channel made through the five way cock. The chuck e has a
small cock Z and also the vacuum chamber has a cock Z. When the apparatus is
not taken from the machine the water cushion W is made either from water already in.
the chamber or the water may be taken direct from an outside position and brought
to the back of the glass.
:: In the first case the vacuum is made in the chamber Hwater is led through
cock Z³ to fill say about one third of the chamber, this water fills the hollow space left
in the spindle down to the cock Z'.
--

page_text: By turning the cock the small pipe is made to communicate with the back of the
glass a little before the water.
The glass may be fixed as follows:-The apparatus is slightly inclined to bring
the vacuum hole higher than any other part. In the space between glass and
chuck the cock Z being open, the air in the space will go up to the Chamber through
pipe a, a, and he rarefied to make equilibrium and the water will fall into the space
by gravity and fill it thus forcing out any air by the hole when the glass would
be ready for use after turning the cock Z' back. The cock is turned back or instead
of having the water in the chamber the glass is laid on the india rubber packing v, v,
then open the cock Z which makes the vacuum at the back of the glass, the water is
run in by small tap Z on chuck, the cock Z' may then be shut when the water fills the
space at the back of the glass, or the glass may lay on the india Rubber packing the
cock is turned to connect the back of the glass with atmospheric pressure or air
hole X the water is run by tap Z on chuck and when the water has filled the space
between glass and chuck it will flow through the air hole X of cock Z, Figure 1A and
thereby show that the space is filled; then the tap Z' is turned off and cock Z' is
turned on to connect the vacuum in chamber H with back of glass or water backing.
In other cases we make the water backing while the apparatus is vertical and the
chuck uppermost. Water is poured into the space made by the form of the chuck, if
it is concave or by the thickness of the small pieces of India Rubber or ring v, v,
until this said space is filled then the glass S is slided on the hollow of the concavity
of the chuck touching the India Rubber at all parts or when the top of the india-
rubber or the glass is flat until the surface of the glass is central with the chuck.
It is quite evident that when the backing or packing is formed that the glass and
the chuck are practically only one having the solid joint of water which is nearly
incompressible so that no strain can happen to the glass while in the process of
roughing smoothing or polishing as the water will fill any space or hollow formed
between the glass and chuck.
Thus as long as the glass touches the india rubber packing the water can be made to
fill the space left which necessitates but few chucks as great varieties of focus can be
held on one chuck.
In the bevelling of very large plate glass which is commonly done in a draw frame
by hand, the glass may be held by the pressure of the atmosphere on a backing of
water. The slab or frame has india-rubber packing at various places. Figure 2
shews the arrangement of the india-rubber for either round or square pieces. When
the chucks are made very large to receive large plates of glass, we call them slab,
frame, or plate and around the periphery and radially to the centre of the plate,
frame or slab, which can be square round or oval, india-rubber packing is fixed as
shown on Figure 2. admitting this chuck represents 7 feet in diameter, the water is
poured into the spaces made by the thickness of the packing v, v, and the glass is
slided slowly starting at one edge of the chuck until it covers the chuck frame, plate
or slab, then the vacuum is applied to the water backing as before described.
Generally in large glass we prefer to hold them at various places on the surface by
small suction plates c, c which are fixed to plate P shewn by Figures 5, 6, 7 and 8
which are different views of a machine to bevel such large plates of glass. This
machine has a bed T and carriage T which receives a to and fro motion by a screw
worked by either left or right band shifted at intervals on the pulley L. The
carriage T¹ carries two vertical standards T on which is fitted a small vertical slide
having open mouthed bearings which receive the pivots P1, P" of the plate or frame P.
To control or incline the plate or frame P to a required angle against the grinder g
we construct a compound lever R having a fulcrum R. One end of the lever is
fixed on a segment piece R² by a pin or screw R³ or any equivalent means. The
other end R has a fork formed to hold a bush r¹ which fitted on the bar and
against which a spiral spring works freely and is held against the said bush by a
regulating wheel nut. The bar being hinged to the frame P the displacement
or oscillation of the frame P to various angles is affected by the lever R and the whole
weight at any position of the frame, rests on the spring which acts as an elastic buffer.
r
?'

page_text: The inclination of the plate or frame P to bevel glass is accomplished by moving
the lever R to any hole made on the quadrant piece which is fastened by pin R³ or
other means can of course be used to secure the lever R such for instance as a set screw.
The lever R has a fulcrum R¹ and the upper end of R is connected to the frame by a
bush which can slide freely upon an hinged bar attached to frame P the bush r¹ is
held by the forked end R and has a tendency through the weight of the frame to
rest on the spiral spring i at all times the tension or elasticity of the said spring can
be increased or decreased by the wheel nut 111 We find that glass of heavy gravity
or weight has momentum according to that said weight and thus it cannot give readily
or is not elastic to any vibration of the frame which is so necessary to work glass but
this spring can be made nearly as sensitive as the hands of a man.
At the back of plate P are one or more vacuum chambers H see Figure 7 on the
drawing which shews only one, the chamber or chambers are connected to the suction
plate c by pipes or tubes i, 1, 12. Figure 7 shews a side view of the plate. Figure S
shews an enlarged view. c is the suction plate fitted in aperture made in the frame
and it has a stem 6 passing through a metal plate or bearing and a screw thread
with a wing nut 62 is made on the part of the stem passing beyond the plate and
spring 6. The stem b finishes in a socket of the cock Z and this cock Z is made
three way so as to communicate with the vacuum chamber by the india-rubber pipe i
or with the atmosphere.
The pipe
or tube i is made of india-rubber or any other elastic material so as to
allow a certain freedom to the suction plate when fixing the plate glass and is con-
nected to the chamber by by the interinediate metal pipes 1, 2 shown in Figure 5 by
dotted lines. To fix a suction plate on the glass, the glass S is laid on the plate P
the suction plate is brought against the glass which action is accomplished by the
pipe being elastic.
When the suction plate touches the glass the tap Z is turned on and the vacuum is
partly made at the back of the part holding on the plate, then to secure firmly the
plate on the frame without injuring the glass, the glass is made to rest upon longitudinal
india-rubber cushions v, v, v, fixed on the frame by screwing in the suction plate c
which is done by wing nut having spring washer 63. The glass is then brought
on the cushion v, v, and to take off a suction plate the cock Z is turned so
as to bring atmospheric pressure into the space made by the glass and chuck, and the
chuck or suction will then come off easily. Each suction plate is operated in the
same manner. It will thus be understood that by these means the plate or plates
must be detached from their suction plate before another side of the glass can be
bevelled which means a loss of time but to avoid this defect at anyrate in limited
sizes we provide an arrangement on a plate to fix on a similar machine which will
bevel the four sides without taking off the glass or the suction plate. Figures 9 and
10 shews the arrangement. o, o are vertical slots made at suitable distances on the
plate P with apertures o², o¹ large enough to pass the chamber H. A guide bar o
made adjustable by set screws o³ is fitted on a sleeve o*. The apparatus is composed
of the chamber H with cocks Z and Z of journal os between guide plates 06, 07, the
chuck e may be made the guide plate itself. The glass being fixed by any of the
methods described, the apparatus with its glass is fitted on the apparatus in
the following manner. The apparatus is passed partly through the aperture o' until
the journal o is central to the thickness of the frame P then the journal is lowered
in the slot o until the guide plate o touches the guide bar o' the very edge of the glass
will be supported by the cushion v of india-rubber and rested on a small metal strip v¹
fitted along the edges of a frame. The guide plate o' or former is made to corespond
to the form of the glass by fitting extending pieces on its edges. It is evident that
when a side has been bevelled the next side can be turned to be bevelled and so on
until the glass is completely done when the apparatus is taken off to another similar
machine to be smoothed and polished.
Now referring to sheet 2 of the drawings:-
Figures 11 and 12 show an improved apparatus to hold by atmospheric pressure

page_text: several small optical glasses on the spherical tool or chuck without being disturbed in
their places while grinding smoothing and polishing.
The glasses S, S are fixed around a segment of a sphere or chuck C on suction
places fitted with small india-rubber packing u, v. The chuck C is made of a radius
to suit the curve to be obtained on the glass fixed on same and is mounted on a
spindle B which runs in bearing B2, B3 and the vacuuin chamber H is fitted on
spindle B¹ and serves as a driving pulley H if desired.
Each glass is independently connected to the vacuum chamber H by independent
pipes, t, t, cocks Z, Z which connect to the chamber H by ring pipe t' and radial
pipes t¹ 11
The grinder or cup g¹ fits over the chuck and receives an angular rotation through
the adjustable slide crank J¹ and pivoting sleeve J2 and J³ fitted on the arm "
formed on cup g¹ by the vertical shaft or spindle J.
The cup gand chuck C represent a cup and ball joint which is a well known device
by which the cup g¹ will follow the curve of the chuck C and at the same time present
a changing surface on the glass so as to equalize the grinding on the same by varying
the angle formed by crank J' and stem g. Different portions of chuck and cup
surface are continually applied to each other. A small trough g is provided on the
top of cup gl concentric to the stem gl" in which sand flows and descends between the
chuck and cup by small holes 1, 1, 1, made on cup at bottom of trough. The sand is
supplied to the trough by the hollow spindle J. The sand is first introduced at the
upper end of the spindle which has a conical mouth piece and it is delivered in the
trough by the hole in the said shaft J. The pressure of the atmosphere acts on
the glasses by the holes 1, 1, made on the surface of the cup.
To rough the glasses when their surfaces are plain a slightly larger cup than the
curve required is used. When the glasses have roughly taken the curve another cup
of the radius required is used. At each change of the cup either to rough smooth or
polish both the chuck C and glasses are well cleaned previous to such change of material
so that any sand emery or other grinding material or coarser particles may be removed
so as to avoid scratches on the surface of the chuck C or glasses, S, S. This process is
continued by different cups until the desired degree of accuracy and polish is obtained.
The crank bar J being adjustable, a different angle is given to the rotation of the
cup g on the chuck C while roughing, smoothing and polishing is going on.
To take off the glasses from the chuck C the cup is lifted from the chuck and the
glasses S, S, are taken off by turning their respective cocks Z, Z1, then these glasses
are fixed with their formed faces to another chuck having suction places to suit the
curved surface made on one side of the glasses and the grinding, smoothing and
polishing operation of the new sides of the glasses is done as before.
Figure 13 shows a section of the cup g¹ and chuck C grinding the next side. It is
evident that the grinding cup may have only vertica! rotation and the chuck receives
the angular rotation as shewn in Figure 12. In this arrangement the chuck with its
spindle g and chamber H receives the angular motion by crank J¹ of the spindle J.
The cup is fixed vertically in bearings and rotates the lens contrary to the motion of
the chuck. When we grind small concaves the glasses are fixed in suction places
made upon the inner face of the cup which in that case becomes the chuck instead
of the spherical chuck C which is then the grinding tool. The machine may in
this case be worked as shown in Figure 12 the cup g¹ having a spindle B¹ and
chamber H fittted as shown in Figure 11 and connecting pipe, t, t, with cocks Z', 'Z'.
The grinding tool has small holes made round its surface to allow atmospheric pressure
to act on the glasses S, S or may be worked as shewn in Figure 11. To rough convex
glasses of various focus we fix the apparatus on which the glass and chamber are filled
on a pivoting frame D Figure 14 having pivots or fulcrum d¹¹, d", fitted in adjustable
bearings d d working upon vertical bars d, d. These said bars d, d, are fixed to a
horizontal carriage A having anti-friction wheels or rollers E¹ E' moving on rails E
to and fro motion being imparted to this carriage A by an eccentric fixed to the vertical
shaft on which is carried the grinder g. Several carriages are fixed radially to the

page_text: horizontal grinder and their to and fro movement is actuated by the same eccentric.
This to and fro movement is necessary when roughing on flat grinder so as to keep the
said grinder surface plane when grinding in concave grinder only the oscillation of the
apparatus and the rotation of the glass is neccessary. The spindle B carrying
the chuck C and chamber H is completely free in its bearing D', D to rise or descend
and the descent is controlled by any suitable arrangement such for instance as the
adjustable collar D'. The oscillation of the apparatus round the pivots d" " is given
by a weight attached to the cord y Figure 15. The glass S in this case has a water
cushion Wand the chuck can be taken off without carrying the whole of apparatus by
unscrewing the chuck C from the spindle B. This is done by shutting the two cocks
and after which the chuck C may be unscrewed and fixed to any other chuck or
any other apparatus for the next process without disturbing the glass from its position
or the said chuck until one face of the glass is completely finished.
The rotation is given to spindle B by a band passing from any suitable overhead
counter shaft to pulley d through bevel wheels D2 and D³. By this means and the
oscillation of the apparatus the glass is forced to present every part of its surface in a
segment of a circle to the horizontal grinder thus presenting every part of its surface
at an equal distance represented by the radius of the pivots du du to the grinder g.
The adjustment or changement from one radius to another is performed by screws K, K
acting equally through suitable gear K', K' and K2, K2 and operated by cords U and
grooved pulley U₁. To grind smooth and polish very shallow curves in large glass
either concave or convox which has radius from say 10 feet to 100 feet we make the
apparatus follow a curve made on two parallel bars F, F, as seen at Figures 16 and 17.
The spindle B with chuck C and chamber H are fitted accurately in two bearings f
and formed in a lantern frame and the weight of spindle chuck and chamber is
supported upon an antifriction box fitted on spindle B and resting on a hard surface
provided on top of bearing. This box has fitted in its interior small hard steel
spheres such as used in bicyle antifriction bearing. The frame f¹ travels on the two
template bars F, F through having two pairs of wheels F2, F2 and F³, F³ fitted on
axis y and y the apparatus and frame is made to rest centrally on the two pairs of
wheels so as to have the weight well balanced on them. These template bars are
supported on bracket N and adjusted by set screws N' acting on a sliding block N'
which carry the template bars F. The spindle B carrying chuck and chamber receives
a slow continuous rotation by the action of the wheels transmitted through clutches Y
to the worm screw Y and worm wheel Y2 fitted on the spindle B. The continuity of
the rotation of the spindle is obtained by mounting on each axis on which each pair
of wheels F, F are fixed, clutches acting opposite to one another so that when the
frame is travelling in one direction a set of clutches Y of the axis y acts on the
worm and worm wheel while the other set of clutches on the axis y¹ is disengaged and
vice-versa when the frame F¹ is travelling in the other direction the clutch engaged
will be thrown out of gear and the one on the other axis will engage with the worm
and screw and wheel and continue the rotation of the spindle B in the same direction
and actuated by the first clutches so that the teeth of one clutch gear with the teeth of
its wheel when turning in one direction while the other is thrown out of gear through
the rotation of its axis turning contrary to the formation of its teeth and to make the
disengagement more certain we may fit a disengaging gear or bar with adjustable
studs or incline such as used in planing machines. The adjustable studs or inclines
mecting a small lever controlling the sliding clutch collar will throw the said clutch
collar out of gear and at the same time engage the other in the teeth of its wheel or
other equivalent means may be used and the grinder smoother or polisher may be
concave or or convex. The template curve may be described from an elliptic, parabolic
or hyperbolic curve.
Having now particularly described ascertained the nature of our said invention and
in what manner the same is to be performed we declare that what we claim is :-

page_text: for the purpose of rendering support to the glass while under treatment substantially
as herein set forth.
Second-The arrangement for holding and manipulating large sheets of glass so
that the edges may be trued bevelled and otherwise worked as well as the India rubber
protections for the edges thereof substantially as herein set forth.
Third The machinery substantially as herein described for completely grinding
spectacle and other such like glasses while they are held by vacuum.
Fourth The radial machinery for grinding lenses whereby the proper curve is given
to the said lenses substantially as herein set forth and illustrated by Figures 14, 15, 16
and 17 on the drawings.
Fifth The improvements in machinery for working glass herein set forth and
shewn on the drawings.
15
11
21
1
1002
GEORGE BARKER,
77, Colmore Row, Birmingham.
Agent for the Applicants.