US1401830A

US1401830A - Method of grinding glass

Info

Publication number: US1401830A
Application number: US420076A
Authority: US
Inventors: Taylor William
Original assignee: Individual
Current assignee: Individual
Priority date: 1915-11-01
Filing date: 1920-10-28
Publication date: 1921-12-27
Anticipated expiration: 1938-12-27
Also published as: GB112349A; FR483734A; US1401832A; US1401831A; GB191515375A; NL8337C

Description

W. TAYLOR.

METHOD or GRINDING GLASS. 7 APPLICATION FILED OCT. 28, 1920.

v 1,401,830. Patented Dec. 27, 1921.

ATTORNEY cairn WILLIAM TAYLOR, OF LEICESTER, ENGLAND.

METHOD OF GRINDING GLASS.

Specification of Letters Patent.

Original application filed October 28, 1916, Serial No. 128,235. Divided and this application filed October To all whom it may 22 061% Be it known that I, lVILLmiLTAYLoR, a citizen of Great Britain. residing at Leicester, in the county of Leicestershire. England, have invented certain new and useful Improvements in Methods of Grinding Glass, fully described and represented in the following specification and the accompanying drawing, forming a part of the same.

This invention relates to 'a method of grinding glass and the like. This application is a division of my co-pending application, Serial No. 128,235, filed October 28 1910, and is directed particularly to a method for grindinga spherical surface. An object of the invention is to provide for rapidly forming a'spherical surface upon a glass blank. The method is particularly adapted-to the grinding of lenses which are to have a deep convex curve.

The accompanying drawing illustrates diagrammatically the carrying out of the method. grinding is done by a cup-shaped wheel, 3 mounted for rotation about an axis a-b.

The lass disk 1 to be ground is carried by. a spi dle 2. The axes of the spindle 2 and the grinding wheel 3 are mounted so as to lie in the same plane. The axis of the work spindle 2 is so mounted that it may be swung about-an axis C intersecting the spindle axis at a point which is the center of the spherical surface to be formed, and preferably at right angles to the common'plane of these axes.

In carrying out the method of grinding, the work spindle is swung slowly to carry the work past the rapidly moving grinding edge of the wheel, preferably so that the grinder attacks first the periphery of the disk and grinds inwardly toward the center. Usually the work spindle is rotated in a direction'to cause the work at the place of contact with the grinding wheel to move in the opposite direction to the movement of the grinding wheel at this point. The rotation of the work is desirably at a comparatively low speed, for example, about 100 revolutions per minute for grinding glass disks one inch in diameter.

The grinding edge of the cup-shaped- As shown in the drawing, the

Serial No. 4201176.

side of. the step formed in the glass is substantially perpendicular to the finished or ground surface of the lens or to the shifting tangent to said surface, throughout the operation, but it is perpendicular to the original flat surface of the disk only at the.

end of the operation at the center of the lens where the depth of the, step is relatively small. In the. early stages of the operation, the original surface of the disk forms, as seen in the drawing, an acute angle with the side of the step, and the consequent.

fragility of the side of the step here facilitates the removal of the glass and enables the wheel to attack successfully a deeper step than it otherwise could.

In. the operation descrlbed the grindingis done upon the side of the circular step,

the wheel contacting with the-surface formed at the base of the step only. By the method described a deep'spherically curved surface is ground on the work by a single cut even when the. blank upon which the operation takes place has at the beginning of the operation a fiat surface or other surface not conforming to the desired spherical face. The method thus affords an extremely rapid and eflici-ent means for grinding a spherical surface upon glass blanks,

I wish it clearly understood that my invention is by no means limited to the specific procedure described in connection. with the accompanying drawing as illustrative of the invention.

Vhat is claimed is:

1. The method of grinding a convex -spher-' ically curved surface upon a flat disk of glass, which comprises rotating the disk upon an axis passing through'the surface to be ground, forming in the surface to be ground a circular step having its center on, the axis of rotation of the disk, grinding back said step to said axis by bringing successive portions of the side of the step into contact with a grinding surface moving along the portion of the side of the step with which it is in contact, and decreasing the depth of the step as it is ground inwardly While varying the angle of the side of-said step to the original surface. of the disk so that it is acute at the beginning of the operation and substantially a right angle at the end of the operation.

2. The method of grinding a desired surface on a glass blank having a surface not conforming to the desired surface to be formed, which comprises rotating the glass blank upon an axis passing through said surface, forming in said surface a circular step having its center on the axis of rotation of the blank, \and grinding back said step continuously from the periphery to the cen- \VILLIAM TAYLOR.

' Witnesses -MA1s1n MAURUs, LILLIAN R. Fox.