Improvements in Lens-grinding Machines.
Year: 1890

page_text: Date of Application, 25th Nov., 1890-Accepted, 10th Jan., 1891
COMPLETE SPECIFICATION.
Improvements in Lens-grinding Machines.
I, RICHARD BENJAMIN HENRY LEIGHTON of Corner of Heggarman and Tyson
Streets, Tacony, in the City and County of Philadelphia and State of Pennsylvania,
United States of America, 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:-
My invention relates to improvements in lens-grinding machines.
It is well known that it is an extremely difficult matter to manufacture a perfect
lens, and that long periods of time are consumed in the manufacture of the larger
telescopic lenses, so that a large lens is only manufactured at great expense.
The object of my invention is to obviate this difficulty, by providing a machine
that will grind a lens of any reasonable size, that may be easily and accurately
adjusted to the various sized lenses, that will grind a perfectly true lens, and that
will be so arranged that the focus of the lens may be changed and regulated to
a nicety.
To this end my invention consists in certain features of construction and com-
binations of parts, which will be hereinafter fully described, and specifically pointed
out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar figures of reference indicate corresponding parts in all
the views.
Figure 1 is a vertical longitudinal section, showing the lens carriage or head block
and the corresponding grinder, on the line 1-1 in Figure 2, the parts being arranged
to grind a convex lens ;
Figure 2 is a plan view of the same;
Figure 3 is a vertical longitudinal section, showing a finer grinder arranged at
right angles to the lens, and mounted upon an oscillating frame;
Figure 4 is a detail side elevation, showing the lens in connection with a finishing
lap, said lap being mounted upon an oscillating carriage, and the lap, lap shaft and
bearings being in vertical section ;
Figure 5 is a detail view of the bed plate and of the radius bar that regulates the
arc of oscillation of the grinder and the focus of the lens ;
Figure 6 an end view of the machine, and also showing the driving mechanism
therefor partly in section ;
Figure 7 an enlarged front elevation of the upper portion of the driving
mechanism;
Figure 8 a broken perspective view of the suspending frame of the upper driving
mechanism;
Figure 9 a plan of the driving mechanism ;
Figure 10 a modified form of carriage, with a finishing tool in position therein;
Figure 11 an end view of said carriage;
Figure 12 a vertical longitudinal section, showing the grinder carriage stationary,
and the lens carriage movable;
Figure 13 a vertical longitudinal section, showing a stationary finishing tool
carriage and a movable lens carriage;
Figure 14 a vertical cross section on the line 14-14 of Figure 1, looking in the
direction of the arrow ;
Figure 15 a vertical cross section on the line 15-15 of Figure 1, looking in the
direction of the arrow;
Figure 16 a vertical cross section on the line 16-16 of Figure 12, looking in
the direction of the arrow;

page_text: Figure 17 a front elevation of the finishing tool and carriage, taken on the
line 17-17 in Figure 13, but with the feed screw and operating gears removed from
the carriage or stand;
Figure 18 is a detail perspective view of the slide by which the radius bar is held
and regulated;
Figure 19 is a side elevation of the lens carriage and grinder as arranged for
grinding a concave lens ;
Figure 20 a plan view of the same;
Figure 21 a broken end view, showing the manner in which the radius bar is fixed
to the lens carriage; and
Figure 22 a detail view of one of the blocks by which the radius bar is fastened
to the lens carriage.
The grinding and lens carrying carriages are supported upon a substantial bed!,
which forms the base of the machine, said bed having a longitudinal recess 2,
extending throughout its entire length, and which is large enough to allow the
slide 3, to move therein, a slot 4, in the bottom of said recess, through which extends
a bolt 5, of the slide, and by means of which the slide is fixed in the recess 2, a
longitudinal T-slot 6. upon each side of the recess 2 and upor the upper flat surface
of the bed, which affords means for bolting the various parts of the machine thereto,
a feed screw and rack 7, 8, like that of an ordinary lathe, and suitable gear
wheels 9, 10, provided with a handle 11, by which said feed screw may be
operated.
The slide 3 is longitudinally movable in the recess 2 of the bed, and is fixed in a
desired position therein by the bolt 5 as described.
The slide has a base plate 31, having inwardly-tapering flanged edges 3ª, upon its
upper side, each of said edges being provided upon its inner side with a slide 3", which
is adjusted by the set screws 3c, so that the plate 12 having beveled edges may fit
nicely between said slides. The plate 12 which is longitudinally-movable upon the
base 31, is regulated by the screws 13, 14, which are mounted in posts 15, on the
base 3¹ in the rear of said plate, the screw 13, abutting directly on the plate 12, and
the screw 14 being connected thereto by means of a nut 16, which is dovetailed into
the rear end of the plate 12, so that the plate may be advanced by turning up the
screws 13 and 14 and retracted by loosening the screw 13 and turning back the
screw 14.
Upon the top of the plate 12, is the bar holder 17, which is a rectangular frame
having a flat base which turns upon the plate 12, and two opposite wide sides 17".
extending above the body of the frame to hold the radius bar as hereinafter
described.
in
The bar holder 17 is attached to the plate 12 by the bolt 18, which has a cylindrical
body portion which turns in the plate 12, an annular flange 18, upon the bottom which
underlies the bottom of the plate 12 and is longitudinally movable in the slot 3d,
the upper part of the base 31, and an inverted cone-shaped upper portion 18", having
its top surface about flush with the narrower sides of the bar holder 17.
Between the sides of the bar holder 17 and the tapering portion 18 of the bolt 18.
are the packing pieces or abutments 19, which have concave inner recesses tapered
oppositely to the portion 18" of the bolt 18, to fit thereon and are fixed in a desired
position against the same by the set screws 20, which project through the sides of the
bar holder 17 and impinge upon the rear sides of the abutments.
It will be thus seen that the bar holder will turn upon a true centre without
variation, and its position may be approximately fixed by moving the base 3' in the
recess 2, and may be nicely adjusted by the screws 13 and 14 as described.
The lens carriage consists of a base plate 21, which extends across the bed 1 and is
provided with removable flanges 21, which overlap the edges of the bed and one of
which connects with the feed screw 7 and carries a pinion 8", engaging the rack 8, by
which the position of the carriage may be adjusted, and a frame 22, mounted upon
the base plate, having a horizontal portion 22ª, above and parallel with the base plate,
and two parallel upwardly-extending arms or supports 22, in line with the bed plate 1,

page_text: said arms being provided with suitable boxes 23, in which turns the hollow shaft 24.
The shaft 24 is made hollow to enable a person to look through the lens and through
the shaft, that he may the better observe the progress of the work.
The shaft 24 is journaled in the boxes 23, is provided with a driving pulley 24*,
with a collar 24, near one end thereof and with a screw-threaded portion 24°, upon
which a holdfast 25, may be screwed.
The hold fast 25 is a little smaller than the lens 26, which is connected thereto, and
is provided with a central threaded hole to receive the shaft 24, with a smooth back
which fits closely against the collar 24", and with a projecting lug 25, with which
engages the bolt 25", which projects through an opposite lug 27, which is pivoted to
the collar 24, and by means of which the position of the holdfast may be nicely
adjusted. The lugs 25 and 27 are placed at an angle to each other, and as the lug 27
and the collar 24" to which it is attached are rigid, when the bolt 25 is turned it
moves the lug 2 and the holdfast 25 to which it is attached, to the right or left as
the case may be.
Longitudinally opposite the base plate 21, is another plate 28, which extends across
the bed 1, having suitable flanges 28", to overlap the edges of the bed and hold the
plate in position thereon, and having upon its upper side, a guide strip 29, which is
suitably supported thereon, so as to extend across the plate and afford rooin for the
end of the radius bar as described below. Said plate is also attached to the bed 1 by
bolts 30, which extend downwardly through the plate and into the slots 6 of
the bed.
Mounted loosely upon the plate 28, so that it may slide thereon is a vertical
frame 31, having a slot 31, upon its under side to receive the radius bar 36, a
horizontal recess 31, which affords room to manipulate the nut on the bolt 32, by
which the frame is attached to the radius bar 36, and arms 31°, extending diagonally
upward and which carry suitable boxes to support the shaft 33. One of the arms 31°
is longer than the other, so that the shaft 33 will lie in a diagonal position. Fixed to
the shaft 33 is an emery wheel 34, or other suitable grinder, and a pulley 35, by which
the shaft and emery wheel are revolved.
The tops of the plates 28 and 21, and the top of bolt 18, should all be on about the
same horizontal plane so that the radius bar 36 may be nearly level, and the centre of
the bolt 18, and of the lens 26 when fixed to the holdfast 25 should be in about the
same vertical line, as hereinafter explained. The radius bar 36 is about the same
length as the bed 1, and is of an even width and thickness throughout, it fits closely
between the upwardly-extending sides 17 of the holder 17 being fixed in a definite
position therein by the set screws 37, in the sides of the holder, is provided with a
hole 36, through which passes the bolt by which it is attached to the movable
frame 31, and fitted upon the bar so as to slide thereon is a block 38, which is
positioned by the set screw 39, and is of a size to just fit between the plate 28 and
guide strip 29, and steady the said bar.
It will thus be seen that the emery wheel 34 will bear against the lens 26, and that
as the grinder frame moves upon the plate 28, it will have a true arc of oscillation, as
the radius bar to which it is connected cannot vary, consequently the lens will be
ground perfectly true. The manner of oscillating the grinder frame will be herein-
after described.
After roughing out the shape of the lens by the emery wheel 34, the frame 31 may
be removed and a frame 40, substituted. The frame 40 has a flat base, which rests
upon and is movable on the plate 28, a slot which fits upon the radius bar 36, a
recess 40, to enable it to be bolted to the bar-like frame 31 already described, and an
upper case 40, having inwardly-tapering sides, and through the sides and bottom of
the case 40 project set-screws 41, by which the frame contained in said case may be
adjusted as described below.
A frame 42, is mounted in the case 40°, said frame having a base 42", which fits in
the case 40, and having two forwardly-extending arms 42°, in vertical alignment, which
are provided with boxes 43, in which turns the vertical shaft 44. The shaft 44 is

page_text: provided with an emery wheel 44", which is fixed thereto and is finer than the
wheel 34, and with a suitable driving pulley 44, to which power is applied to rotate
the shaft and einery wheel.
By having the emery wheel 44" mounted upon a vertical shaft it will bear upon the
lens 26 at a different angle from the wheel 34, and will remove any scratches that the
coarser wheel may have left in the glass.
To finish smoothing the iens, the frame 42 is removed from the case 40°, and the
frame 45, inserted. The frame 45 has a wide base 45, which fits between the
tapering sides of the case 40°, and two vertical arms 45b, carrying suitable boxes in
which turns the hollow shaft 46.
The shaft 46, has a driving pulley 46", affixed thereto by which it may be rotated,
and has at the end next the lens, a collar 46°, to which is attached the finishing
lap 47.
The lap 47 is shaped to fit nicely upon the lens 26, is provided with intersecting
grooves 47ª, upon its face and with perforations 47%, which communicate with the
hollow shaft 46, so that the shaft may be filled with liquid charged with emery or
other sharp substance, and the liquid will flow through the perforations and be
diffused over the face of the lap by means of the grooves 47*, thus enabling the lap to
rapidly polish the lens.
The frame 45 may be tilted in any direction so as to bring the lap 47 firmly and
squarely upon the lens, by means of the set-screws 41, which project through the
sides of the case 40° and impinge upon the base of the frame. By loosening the set-
screws upon one side of the case and tightening them upon the other, and by raising
or lowering the set-screws in the bottom of the case, the frame contained therein may
be tilted and held in any desired position.
The lens and grinders are rotated and the grinding carriages oscillated by means of
the following described mechanism.
The power is taken from a main shaft 48, which is suitably mounted at right angles
to the machine. Below the shaft and near the bed 1, is a gear wheel 49, mounted
upon the vertical shaft 50, which turns in the frame 51, which rests upon the floor.
Mounted in suitable supports 52, adjacent to said gear wheel, is a shaft 53, having a
pulley 53, connecting by a belt 54, with a pulley of the main shaft, a worm 53,
which meshes with the gear wheel 49, so as to slowly turn the same, and a pulley 53,
which connects by a belt 55, with the pulley 24" of the shaft 24 and turns the lens, as
shown in Figure 6. As will be hereinafter described, sometimes the lens carriage is
stationary and the grinding mechanism oscillates, and sometimes these conditions are
reversed, and the belt 55, is connected with the shaft of the part that is stationary.
In the upper face of the gear wheel 49, is a diametrical slot 49", extending across
the same, and in which a bolt 56, is fixed, to attach the connecting rod 57, to the
gear wheel.
The connecting rod 57 is pivoted at one end to the bolt 56, and at the other to the
bar 58, one end of which is attached to the frame 31, or 40, as the case may be, and
the other end of which extends upwardly and is connected by means of the guide
bar 59, with the slotte guide 60, of the rectangular frame 61.
The frame 61 is suspended in a horizontal position above the grinding machine
and in line therewith, by the shaft 6, which extends from the ceiling through a
cross bar 61ª, of the frame, and to which shaft the frame is pivoted, and by the
curved suspending frame 63, which is bolted to the ceiling or other support, and
upon which fit the arms 64, which are suitably attached to the frame 61 and have
bifurcated ends 64", to slide upon the frame 63. The frame 61 may thus turn upon
the shaft. 62 and oscillate in unison with the parts below. The shaft 62 is provided
with grooved pulleys 62, one of which connects by a belt 64, with a pulley upon
the counter shaft 65, said counter shaft being suitably connected with the main
shaft 48 below, and the other of which connects by a belt 66, with one of the
pulleys 67, which are fixed to the vertical shaft. 67, of the frame 68, so that
practically the pulleys 67 and 62 will be in opposite corners of the frame 61. The

page_text: shaft 67 is supported by a framework 69d, attached to the upper side of the
frame 68, and which may be provided with several similar shafts and pulleys mounted
in suitable boxes as shown, and which may be used if desired.
The frame 68 is shorter than the frame 61, in which it may be moved longitudinally
by loosening the bolts by which it is attached thereto; it is provided with flanges 68",
which support it upon the frame 61, with bolts 68b, by which it may be attachel to
the frame 61, and with set screws 68, which project through the frame and impinge
upon the frame 61, by which the frame 68 may be raised from the frame 61. This
will be necessary sometimes, to tighten the belts which extend from the pulleys of
the frame 68, to the mechanism below, as the belts are whole belts, it being
impracticable to use laced belts in lens grinding as the operation is one of such
nicety and the lacings cause a jar as they pass over the pulleys.
Extending longitudinally across the frame 68, are the shafts 69 and 70, having
fixed thereto or formed thereon the drum pulleys 69" and 70", which extend nearly
the length of the frame 68, and at one end of each of which is a grooved pulley 69b
and 70%, which are connected by a suitable belt by which power is transmitted from
one shaft to the other. The shaft 70 projects through one end of the frame 68,
and is provided on said projecting end with a grooved pulley 70°, by which the
shaft 70 is driven, said pulley being connected by a suitable belt with one of the
pulleys 67, on the vertical shaft 67".
The drum pulleys may be severally connected with the travelling mechanism
below, to revolve an emery wheel or grinder as the case may be, and the drum
pulleys being long, as shown, will allow the belt which passes over them to move
longitudinally thereon, to conform to the change in distance between a certain
point of the pulley and the mechanism below, caused by the oscillation of said
mechanism and of the frames 61 and 68.-
As the frame 61 is connected by the guide bar 59 with the oscillating mechanism
below, it will be seen that there will be several movements going on at the same
time, consequently the work will be done very rapidly. The lens will be revolved
in one direction, the grinding wheels in an opposite direction, and as the grinding
frame will oscillate in a true arc as determined by the radius bar 36, every part of
the lens will be evenly and perfectly smooth.
In Figures 12 and 13, I have shown another method of grinding a convex lens in
which the grinding frames are stationary and the lens carriage is oscillated, the details
of this construction being more fully shown in Figures 21 and 22.
In this case the plate 28 is moved nearer the slide 3, the flanges 21ª are removed
from the base plate 21, and the plate 21, mounted upon the plate 28, the radius bar 36
is bolted to the frame 22, or the plate 21, and is held in position by the blocks 71,
which fit closely upon the radius. bar, extend to the sides of the frame 22, and are
bolted or screwed to the plate 21, the block 38 is moved upon the radius har so as to
move between the guide strip 29 and the plate 28, and the gear wheel 49 and the
mechanism for driving the same, are placed in line with the lens carriage, and
attached thereto and connected with the frame 61 above, in the same manner that said
mechanism was connected with the frames 31 or 40, as described.
When the lens carriage is oscillated, a stand 72, is fixed to the bed 1, opposite the
lens carriage, and the frames carrying the grinding tools severally mounted thereon.
The stand 72 is provided with side pieces 72", which raise it from the bed 1 and
allow the end of the radius bar 36 to swing beneath it, and upon the top with a
suitable tapering case or slide, as 40°, to receive and hold the base of the frames 42
or 45. To grind the lens, the frame 42. with the grinding mechanism already
described, is fastened in the slide 40%, and the driving, pulley thereof connected with
the shaft 53; the frame 68 is moved in the frame 61, so as to be above the lens
carriage, and one of the drum pulleys thereof is connected with shaft of the lens
carriage; the lens carriage will then be oscillated, and also guided by the radius
har 36, so that a true lens will be formed.
To polish the lens, the frame 42 is removed from the slide 40° and the frame 45
carrying the finishing lap 47 is inserted, and this mechanism will operate as already

page_text: described, except that the lens will oscillate and the grinding frame will be
stationary. Instead of mounting the frame 45 in the slide 40°, the stand 72 may be
removed, the stand 73 fixed in its place, and the frame 40 carrying frame 45,
mounted therein.
The stand 73 has flanges 73ª, to hold it in position upon the bed 1, although it is
also bolted thereto, inwardly-tapering sides 73, to hold a frame in place therein, and
is provided with a feed screw 74, which is suitably mounted therein, said screw
extending longitudinally across the stand 73, and having at one end a pinion 74,
connecting with a gear wheel 75 and handle 76, by which it may be operated. The
frame 40 has a slot 40, extending across the bottom thereof, the upper portion of
said slot being screw-threaded to fit the screw 74. When the frame 40 is placed
in the stand 73, the slot 40d is placed upon the screw 74, and by turning the
screw the position of the frame may be very nicely adjusted. The slot 40d is
screw-threaded on the upper side only, and the weight of the frame 40 causes
the screw-thread to he engaged by the screw 74.
.
In Figures 19 and 20, I have shown the machine as arranged to grind a con-
cave lens.
In this case the lens carriage is nearer the free end of the radius
bar 36 and the grinding mechanisin placed nearer the slide 3. As shown in the
drawings the lens carriage is attached to the radius bar, and is to be oscillated,
but either part may be oscillated in the same manner as when a convex lens is
to be formed.
By placing the grinding mechanism between the lens carriage and the slide 3,
it is obvious that a concave surface will be formed on the lens, as the lens will
represent a longer are of oscillation than the grinding tool, and the degree of
concavity is regulated by changing the length of the radius bar in the manner
already described.
In operating the machine, power is applied by means of the various belts as
already described, the gear wheel 49 as it revolves will oscillate the carriage or
frame with which it is connected by the rods 57 and 58, the guide bar 59 will
cause the overhead frames to move in unison with the lower parts, the radius
bar 36 will hold the movable carriage in such a manner that it will describe a
true are, and as a result the lens must be perfectly ground.
A more detailed description of the manner in which the machine is operated will
not be necessary. as the operation of the various parts has been set forth in the
description. I do not confine myself to the precise construction of parts set forth in
this Specification, as the various frames and carriages might be greatly changed with-
out departing from the principle of my invention. It is obvious too that the bed 1
and the horizontal frames 61 and 68 might be placed in a vertical position, and the
various carriages attached in the bed.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is-
1. In a lens-grinding machine, the combination, with a bed and a fixed carriage
carrying a lens, of a radius bar pivoted on the bed, and a second carriage movable on
the bed and carrying a grinding tool, said second carriage being secured to the radius
bar, substantially as described.
2. In a lens-grinding machine, the combination, with a bed, of a fixed and a circularly-
reciprocating carriage, one of said carriages carrying a hollow revoluble shaft having
a lens-holder secured to one end thereof, and the other carriage carrying a revoluble
shaft having a grinding.tool secured thereto, and means for holding the reciprocating
carriage in a fixed arc, substantially as described.
3. A lens-grinding machine, having a stationary carriage carrying a rotatable shaft
provided with a holdfast to which the lens may be attached, and an oscillating
carriage in line with said stationary carriage, having a rotatable grinding wheel
mounted therein, which may be brought against the face of the lens, substantially as
described.
4. A lens-grinding machine, consisting essentially of a bed plate, a stationary

page_text: carriage mounted thereon, having a shaft mounted therein, an oscillating frame or
carriage in line with said stationary carriage and having a shaft mounted therein, one.
of said shafts carrying a holdfast and the other a grinding wheel, and a bar pivoted
in line with said carriages and attached to the oscillating frame or carriage to
determine its arc of oscillation, substantially as described.
5. A lens-grinding machine, consisting essentially of a bed plate having a
longitudinal recess therein, a slide movable in said recess and having a bar holder
pivoted thereon, a carriage mounted upon the bed plate and having a rotatable
horizontal shaft provided with a holdfast to which the lens may be attached, a second
carriage mounted upon the bed plate in line with said lens carriage and having a
rotatable grinding wheel which may be brought in contact with the lens, means, as
shown, for oscillating one of said carriages, and a bar connecting the oscillating
carriage with the bar holder of the slide, so as to determine the arc of oscillation of
said carriage, substantially as described.
6. A lens-grinding machine, consisting essentially of a bed plate having a
longitudinal recess therein, a slide movable in said recess and having a bar holder
pivoted thereon, a carriage mounted upon the bed plate having a rotatable horizontal
shaft provided with a holdfast to which the lens may be attached, a second carriage
mounted upon the bed plate in line with said lens carriage, having a rotatable
grinding wheel which may be brought in contact with the lens, means, as shown, for
oscillating one of said carriages, a bar connecting the oscillating carriage with the bar
holder of the slide, so as to determine the arc of oscillation of said carriage, and means
for adjusting the bar holder, substantially as described.
7. A lens grinding machine, consisting essentially of a bed plate having a
longitudinal recess therein, a slide movable in said recess and having a pivoted bar
holder thereon, a carriage mounted upon said bed plate, having a rotatable shaft with
a hold fast fixed thereto to which a lens may be attached, a carriage mounted upon
the bed plate in line with said lens carriage, having a rotatable grinding wheel
mounted therein which may be brought against the lens, means, as shown, for
oscillating one of said carriages, a bar connecting the oscillating carriage with the
pivoted bar holder, and a frame mounted above said carriages and arranged to
oscillate in unison therewith, said frame having revolving pulleys therein which may
be connected with the shaft of the oscillating carriage, substantially as described.
8. In a lens-grinding machine, the slide 3, having tapering sides 3", provided with
adjustable slides 3, the plate 12, movable between said sides, the bar holder 17,
having upwardly-extending sides 17", the bolt 18, having flange 18 and tapering
portion 18, for attaching the holder to the plate 12, the abutments 19, to fit the
part 18, and means, as screws 13, 14, posts 15 and nut 16, for moving the plate 12
and holder 17, substantially as described.
9. The combination, with the bar 36, fixed to the bar holder 17, and to an
oscillating frame of the machine, as shown, of the plate 28, having guide strip 29, and
movable block 38, for steadying the bar, substantially as described.
10. The combination, with the slide 3, having sliding plate 12, and the bar holder 17,
pivoted thereon, of the bar 36, having means, as shown, for attaching it to an
oscillating carriage or frame, and means, as screws 13 and 14, post 15 and nut 16, for
adjusting said bar, substantially as described.
11. The combination, with an oscillating frame or carriage of a lens-grinding
machine, having a rotatable shaft therein, of the frame 61, pivoted above said
carriage, means, as guide bar 59, guide strip 60, connecting rods 57, 58, and gear
wheel 49, for moving said frame in unison with said carriage, the frame 68,
adjustably mounted in the frame 61, and provided with the vertical shaft 67",
carrying pulleys 67, the horizontal drum pulleys 69 and 70%, and grooved
pulleys 69, 70 and 70b; and suitable belts for operating said pulleys and for
connecting the drum pulleys with the oscillating carriage, substantially as described.
12. The combination, with the frame 61, pivoted above the grinding mechanism,
as shown, of the frame 68, mounted in the frame 61, having revolving pulleys
mounted therein connecting with the grinding mechanism, and means, as
set

page_text: screws 68°, for raising the frame 68 and tightening the connecting belts, substantially
as described.
13. The combination, with a frame, as 42 or 45, having a suitable grinding wheel
mounted therein and having a widened base as shown, of the case 40°, mounted upon
a suitable stand and having set screws 41, projecting through the same and impinging
upon the base of said grinding frame and adapted to regulate the position theroof,
substantially as described.
14. The combination, with the stand 73, having flanges 73* and tapering sides 73b,
and the screws 74, mounted in said stand and having means, as pinion 74°, gear
wheel 75 and handle 76, for actuating the same, of the frame 40, having a slot 40,
provided with a thread to fit the screw 74, the case 40°, fixed to said frame, and the
grinding frame 45, mounted in said case and provided with a rotatable grinding
wheel, substantially as described.
Dated this 25th day of November 1890.
R. B. H. LEIGHTON.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
R. B. H. LEIGHTON.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.