Gauges for Centering Lenses and Making other Optical Measurements.
Year: 1891

page_text: Date of Application, 6th June, 1891.
Complete Specification Left, 1st Jan., 1892-Accepted, 19th Mar., 1892
PROVISIONAL SPECIFICATION...
Gauges for Centering Lenses and Making other Optical
Measurements.
A communication from ANDREW L. SMITH, of 23, Washington Street, in the
City of Chicago, County of Cook and State of Illinois, United States of
America, Manufacturer.
.
I, WILLIAM LLOYD WISE of 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Patent Agent, do hereby declare the nature of
this invention to be as follows:-
The device described and shown herein is based on the fact that the thickness of
a lens taken at several points symmetrically located with reference to its centre or
axis are equal and planes cutting the lens upon its opposite sides and passing
through these points are parallel. Its main clements are two or more series of
contact points which may be designated as opposed because they act on the
opposite sides of the lens, one series of said points being movable relatively to the
other, and one or both series having indicating devices whereby the parallelism or
inclination of the planes of said series of points is registered.
The device when provided with a centre-indicating point is adapted not only for
ascertaining the centres of lenses but also by means of the indicating devices first
referred to, adapted for measuring the angles of prisms, and for determining the
axes of cylindrical lenses, and for other similar purposes of the optician, as will
hereinafter appear.
In the accompanying drawings,
Fig. 1 is a side elevation, and
1:
Fig. 2 is an end elevation of a simple form of device embodying my invention.
Figs. 3 and 4 are plan views of the same, the upper portion of the device being.
removed in Fig. 4 so as to shew the base of the instrument more clearly; and
Fig. 5 is a view of the lens, illustrating the manner in which it is centred by the
instrument.
4
Figs. 6 to 9 shew a more elaborate and complete form of the instrument by which
the lens may be centred in a single operation.
Fig. 6 is a side view partially in section;
Fig. 7 is an end view also partially in section;
Fig. 8 is a plan, and
Fig. 9 is a horizontal section on line 9, 9 of Fig. 6.
The mounting or frame of the device, as shown in the first form, consists of two
principal parts, a base A and a hinged, sliding or torsion bracket B. The base is
supported upon suitable legs C and upon its upper surface near one end are fixed
two studs or pins D, D', whose upper ends are pointed (or are otherwise suitably
shaped for the lens,) and on said upper surface is a circular dial E whose centre is
at a point midway between the contact-points of the studs D, D. A spring S is
used as a matter of convenience for supporting the bracket B with a yielding.
pressure. The bracket B is hinged to the opposite end of the base A and its
upright portion forms a sectional dial whose graduations are shown in Fig. 2 at the
upper portion of said bracket.
Pivoted at F to the lower portion or upright face of the bracket B is a lever G,
provided with contact-points H, H', opposite to the contact-points of the.
studs D, D. Midway between the contact points H, H' is an indicating point 1.
Attached to, or forming part of the lever G, is an index or pointer J extending.
over the graduations on the face of the bracket B heretofore referred to. The
contact points, H, H' are so situated with reference to the contact points of the..

page_text: studs D, D that when the distance between the points H. and D is equal to
the distance between the points H', D', so that parallel planes could be passed
through the points H, H' and D, D₁ respectively, the index J will stand at zero,
while the movement of the lever G upon its pivot F, so as to destroy the equality
of the distance between the points H, D and D', H', will be measured by the
reading of the index J upon its dial.
In the drawings the points H, H¹ are equidistant and the contact points D D
are equidistant from a central line a, a, which is common to both H, H' and D, D'
when the index J stands at zero, as shown in Fig. 2, and the point I lies in the
said central line, which will coincide with the centre of the lens; but it is only
necessary to the operation of the device that the points H, H and the contac
points of D, D₁ shall be, when in parallel planes, symmetrically arranged with
reference to said common central line, the distance of the points H and H¹ not
being necessarily the same as the distance of the contact points D, D₁ from their
common central line.
The operation of the device in ascertaining the centre of a lens, as K, may be
seen in Figs. 1 and 2. The lens is inserted between the contact points H, D
and H, D₁ so that the plane of the points H, D-H', D' shall bisect the lens as
nearly as the eye can determine, and the lens is then shifted sidewise until the
pointer stands at zero. Its centre will then be indicated by the point I; that is
to say, the centre will lie in a line (a a, Fig. 5) passing immediately beneath the
point I at right angles to the plane of the contact points H, D, FI', D. The point
upon the lens immediately beneath the point I may be marked in any suitable
manner and the lens is then revolved ninety degrees, approximately, so that the
imaginary line a a (Fig. 5) will be brought in the plane of the contact points and
is again centred. Thus, a point in the imaginary line bb (Fig. 5) passing through
the centre of the lens is ascertained. If this point coincides with the point of the
line a, a first ascertained, the centre of the lens is determined. If the second
point ascertained does not coincide with the first, the first must be shifted along
the line aa until a coincidence is secured, and one or two trials, which can be
almost instantly made, will be sufficient to accurately centre the lens, as a close
approximation can be secured by the first centering.
But in order to accurately centre the lens at a single trial I prefer the device
shown in Figs. 6-9 inclusive, which device is also specially adapted for ascer-
taining the axis of a cylindrical lens.
The measurement of the angle of a prism can be made at a single movement by
placing it between the contact points and revolving it about the centre I, slightly,
so as to ascertain the maximum reading of the pointer J.
The movement so imparted to the lever G and its contact points will destroy
the cquality of the distance of the points H H' from the centre line a, x, (Fig. 2);
but the accuracy of the measurement of the angle of the prism will not be
affected thereby as the spacing of the degrees upon the scale of the pointer J may
be properly adjusted to give the true readings. To ascertain the axis of a
cylindrical lens with this device the lens is rotated until a position is found which
permits the lens to be moved from side to side in the direction of the line joining
the contact points without moving the index J from zero.
The position of the axis of said lens can be marked in any suitable manner
and the graduated scale E will enable it to be marked so that the axis can be
placed at any desired augle in the spectacle frame.
Referring to the more elaborate form of instrument shown in Figs. 6-9
inclusive.
The two parts of the frame, consisting of the base A' and the arm or bracket B₁
are rigidly joined and may be made of a single casting. In the face of the
bracket B is a groove having fitted therein a slide L to which the lever C' is
pivotted. Said lever C differs from the lever G, heretofore described, in having
four contact points H, H1, H2, H3, instead of two; said points being arranged
aymmetrically around the point I which indicates the centre of the lens. The

page_text: lower series of bearing points opposed to the points H, H', H³, H³, are formed
upon two pivoted levers M, N, the points of said levers being likewise symmetrically.
arranged in reference to the central point I'. The plane of their pivotal points is
at right angles to the plane of the pivot of the lever C'.
Each lever M, N, is provided with a pointer over a graduated scale at the base
of the instrument and when the planes of the contact points of the levers -M; N
coincide and their indexes stand at zero upon their respective scales, said plane
would be parallel to the plane of the contact points H, H1, H2, H3, when the index
of the lever C stands at zero. Thus, if a spherical lens, either convex or concave,
be placed in the instrument so as to make contact with all the points and all three
indexes stand at zero, the point I will be opposite the centre of the lens. If a
cylindrical lens be placed upon the contact points of the lever M, N, its axis will
be parallel to the plane of the pivots of said levers when their indexes stand at
zero. The position of the axis of the lens can be determined most accurately. A
circular scale E', whose purpose is the same as that of the scale E described in
connection with the first form of the instrument, is provided.
It is obvious that in connection with the pivoted levers M, N, a lever C' having
a single pair of opposed bearing points, such as are used in connection with the first
form of the instrument, may be substituted for the lever C' having four bearing
points, it being only necessary that said single pair of points should be located
symmetrically with reference to the central point and the points of the
levers M, N.
The operation of measuring the angle of a prism with the device last described
is practically the same as with the first described form, and needs no further
description.
Deted this 5th dow of Luna 1001
W. LLOYD WISE,
Per F. J. Brougham.
COMPLETE SPECIFICATION?
Gauges for Centering Lenses and Making other Optical
Measurements.
A communication from ANDREW L. SMITH, of 23, Washington Street, in the City
of Chicago, County of Cook and State of Illinois, United States of America,
Manufacturer.
1, WILLIAM LLOYD WISE of 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Patent Agent, 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 device described and shown herein is based on the fact that the thickness
of a lens taken at several points symmetrically located with reference to its center
or axis are equal and planes cutting the lens upon its opposite sides and passing
through these points are parallel. Its main elements are two or more series of
contact points which may be designated as opposed because they act on the opposite
sides of the lens, one series of said points being movable relatively to the other,
and one or both series having indicating devices whereby the parallelism or inclina-
tion of the planes of said series of points is registered.
The device when provided with a center-indicating point is adapted not only for
ascertaining the centers of lenses but also by means of the indicating devices first
referred to, adapted for measuring the angles of prisms, and for determining the
axes of cylindrical leuses, and for other similar purposes of the optician, as will
hereinafter appear.
In the drawings, filed with my Provisional Specification
Figure 1 is a side elevation, and
Figure 2 is an end elevation of a simple form of device embodying my invention.

page_text: Figures 3 and 4 are plan views of the same, the upper portion of the device being
removed in Figure 4 so as to show the base of the instrument more clearly; and
Figure 5 is a view of the lens, illustrating the manner in which it is centered by
the instrument.
Figures 6 to 9 show a more elaborate and complete form of the instrument by
which the lens may be centered in a single operation.
Figure 6 is a side view partially in section;
Figure 7 is an end view also partially in section;
Figure 8 is a plan, and
Figure 9 is a horizontal section on line g, 9, of Figure 6.
The mounting or frame of the device, as shown in the first form, consists of two
principal parts, a base A and a hinged, sliding or torsion bracket B. The base is
supported upon suitable legs C and upon its upper surface near one end are fixed
two studs or pins D, D', whose upper ends are pointed (or are otherwise suitably
shaped for the lens), and on said upper surface is a circular dial E whose center is
at a point midway between the contact-points of the studs D, D'. This dial enables
the lens when being tested to be rotated through any desired angle with great
precision. A spring S is used as a matter of convenience for supporting the
bracket B with a yielding pressure. The bracket B is hinged to the opposite end
of the base A and its upright portion forms a sectional dial whose graduations are
shown in Figure 2 at the upper portion of said bracket.
Pivoted at F to the lower portion or upright face of the bracket B is a lever G,
provided with contact-points H, H', opposite to the contact-points of the
studs D, D. Midway between the contact-points H, H is an indicating point I.
Attached to, or forming part of the lever G, is an index or pointer J extending
over the graduations on the face of the bracket B heretofore referred to. The
contact-points H, H' are so situated with reference to the contact-points of the
studs D, D' that when the distance between the points H and D is equal to the dis-
tance between the points H', D', so that parallel planes could be passed through
the points H, H¹ and D, D' respectively, the index J will stand at zero, while the
movement of the lever G upon its pivot F, so as to destroy the equality of the dis-
tance between the points H, D and D', H', will be measured by the reading of the
index J upon its dial.
In the drawings the points H, H' are equidistant and the contact-points D, D'
are equidistant from a central line X, X, which is common to both H, H¹
and D, D¹ when the index J stands at zero, as shown in Figure 2, and the point I
lies in the said central line, which will coincide with the center of the lens; but
it is only necessary to the operation of the device that the points H, H' and the
contact-points of D, D' shall be, when in parallel planes, symmetrically arranged
with reference to said common central line, the distance of the points H and H'
not being necessarily the same as the distance of the contact points D, D' from
their conimon central line.
The operation of the device in ascertaining the center of a lens, as K, may be
seen in Figures 1 and 2. The lens is inserted between the contact points H, D
and H, D so that the plane of the points H, D-H', D' shall bisect the lens as
nearly as the eye can determine, and the lens is then shifted sidewise until the
pointer J stands at zero. Its center will then be indicated by the point I; that is
to say, the center will lie in a line (a a, Fig. 5) passing immediately beneath the
point I at right angles to the plane of the contact-points H, D, H', D'. The point
upon the lens immediately beneath the point I may be marked in any suitable
manner and the lens is then by reference to the scale E revolved ninety degrees,
approximately, so that the imaginary line a a (Fig. 5) will be brought in the plane
of the contact points and is again centered. Thus, a point in the imaginary
line, (Fig. 5) passing through the center of the lens is ascertained. If this
point coincides with the point of the line a, a first ascertained, the center of the
lens is determined. If the second point ascertained does not coincide with the
first, the first must be shifted. along the line a a until a coincidence is secured, and

page_text: one or two trials, which can be almost instantly made, will be sufficient to
accurately center the lens, as a close approximation can be secured by the first
centering.
But in order to accurately center the lens at a single trial I prefer the device
shown in Figures 6 to 9 inclusive, which device is also specially adapted for ascer-
taining the axis of a cylindrical lens.
The measurement of the angle of a prism can be made at a single movement by
placing it between the contact points and revolving it about the center I, slightly,
so as to ascertain the maximum reading of the pointer J.
The movement so imparted to the lever G and its contact points will destroy the
equality of the distance of the points H, H' from the center line X, X (Fig. 2);
but the accuracy of the measurement of the angle of the prism will not be affected.
thereby, as the spacing of the degrees upon the scale of the pointer J may be
properly adjusted to give the true readings. To ascertain the axis of a cylindrical
lens is rotated until a position is found which permits the lens to be moved from
side to side in the direction of the line joining the contact-points without moving
the index F from zero.
The position of the axis of said lens can be marked in any suitable manner and
the graduated scale E will enable it to be marked so that the axis can be placed at
any desired angle in the spectacle frame.
"
Referring to the more elaborate form of instrument shown in Figures 6 to 9
inclusive:
The two parts of the frame, consisting of the base A' and the arm or bracket B',
are rigidly joined and inay be made of a single casting. In the face of the
bracket B is a groove having fitted therein a slide L to which the lever C is
pivoted. Said lover C differs from the lever G, heretofore described, in having
four contact points H, H1, H2, H3, instead of two; said points being arranged
symmetrically around the point I' which indicates the center of the lens. The
lower series of bearing points opposed to the points H, H1, H2, H3, are formed
upon two pivoted levers M, N, the points of said levers being likewise symmetrically
arranged in reference to the central point I'. The plane of their pivotal points is
at right angles to the plane of the pivot of the lever C¹.
Each lever M, N, is provided with a pointer over a graduated scale at the base
of the instrument and when the planes of the contact points of the levers M, N
coincide and their indexes stand at zero upon their respective scales, said plane
would be parallel to the plane of the contact points H, H', H2, H3, when the index
of the lever C stands at zero. Thus, if a spherical lens, either convex or concn ve,
be placed in the instrument so as to make contact with all the points and all three
indexes stand at zero, the point I will be opposite the center of the lens. If a
cylindrical lens be placed upon the contact points of the lever M, N, its axis will
be parallel to the plane of the pivots of said levers when their indexes stand at
The position of the axis of the lens can be determined most accurately. A
circular scale E', whose purpose is the same as that of the scale E described in
connection with the first form of the instrument, is provided.
zero.
It is obvious that in connection with the pivoted levers M, N, a lever G having
a single pair of opposed bearing points, such as are used in connection with the first
form of the instrument, may be substituted for the lever C'having four bearing
points, it being only necessary that said single pair of points should be located
symmetrically with reference to the central point I and the points of the
levers M, N. The operation of measuring the angle of a prism with the device
last described is practically the same as with the first described form, and needs no
further description.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. The combination, in an instrument of the character described, of a series of

page_text: bearing points and a lever having a series of contact points opposed to said bearing
points, and an index or pointer connected to said lever and indicating upon a suit-
able graduated scale the relative inclination of the respective planes of said
several series of points, substantially as described and as illustrated by the
drawings.
2. The combination, in an instrument of the character described, of a series of
bearing points and a lever having contact points opposed to said bearing points,
and an index or pointer connected to said lever and indicating upon a suitable
graduated scale the relative inclination of the respective planes of said several
opposed series of points, and an indicating point situated midway between the
lever contact points, substantially as described and as illustrated by the drawings.
3. The combination, in an instrument of the character described, of bearing
points and a lever having contact-points opposed to said first named points, and an
index or pointer connected to said lever and indicating upon a suitable graduated
scale the relative inclination of the planes of said opposed series of points and an
indicating point situated midway between said bearing points, substantially as
described and as illustrated by the drawings.
4. The combination, in an instrument of the character described, of bearing
points and a lever having contact points opposed to said first named points, and an
index or pointer connected to said lever and indicating upon a suitable scale the
relative inclination of the respective planes of said opposed points, and a graduated
dial whose center is located at the center of one of said series of points, substantially
as described and as illustrated by the drawings.
.
5. The combination in an instrument of the character described, of a series of
bearing points formed upon a lever or levers, and an opposed series of bearing
points formed upon a lever or levers, and devices connected to said levers, whereby
the relative inclination of the respective planes of said opposed series of bearing
points are indicated, substantially as described and as illustrated by the drawings.
6. The combination, in an instrument of the character described, of a series of
bearing points formed upon a lever or levers, and an opposed series of bearing
points formed upon a lever or levers, the plane of the axis of the said last named
lever being at right angles to the plane of the axis of the first named series of levers,
substantially as described and as illustrated by the drawings.
7. The combination, in an instrument of the character described, of levers
as M, N, having bearing or contact points actuating indexes or pointers, and scales
graduated to show the coincidence of inclination of said points with a single plane,
substantially as described and as illustrated by the drawings.
Dated this 1st day of January 1909
W. LLOYD WISE,
Per F. J. Brougham.