US461320A

US461320A - Test-type for opticians and oculists

Info

Publication number: US461320A
Authority: US
Publication date: 1891-10-13
Anticipated expiration: 1908-10-13

Description

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Patented 001. 13, 1891.

E. & L. CLAUDEL. TEST TYPE T011 oPTIoIANs AND 'ooULIsTs THE NGRRIS PETERS C0 PNOTO- IYNO WASHINGTON D C UNITED STATESv PATENT OFFICE.

EDVARD CLAUDEL AND LOUIS CLAUDEL, OF NEV ORLEANS, LOUISIANA.

TEST-TYPE FOR OPTICIANS AND OCULISTS.

SPECIFICATION forming part of Letters Patent No. 461,320, dated October 13, 1891.

Application filed April 11, 1891.

Vsuch as will enable others skilled in the art to which it appertains to make and use the same. Y

This invention has relation to improvements in devices employed by Opticians and oculists to test a patients strength of sight; and it has for its object to provide a device of cheap and simple construction adapted to be readily manipulated, whereby test-types or print of various degrees of fineness may be successively brought into alignment with an opening and before a patients eyes, and the strength of sight thereby determined.

To the accomplishment ofthe foregoing and other objects, the invention consists in the construction, novel combination, and adaptation of parts hereinafter described, and particularly pointed out in the claim appended.

In the accompanying drawings, Figure l is a front elevation of our improved device. Fig. 2 is a rear elevation of the same. Fig. 3 is a horizontal transverse sectional view, and Fig. 4 is a front elevation, of the slide bearing the test type or print.

Referring by letter to the said drawings, A indicates the main or face board of our im-y proved device, which is preferably of a rectangular form. This face-board A is provided at about the proportional elevation illustrated with a horizontally-disposed rectangular opening a, through which'the respective species of type or print are exhibitedto the patient, and the said rectangular opening d is preferably provided with a dark or black border, whereby the print is thrown into relief.

Attached to the back of the board A, adjacent to the longitudinal edges thereof, are longitudinal strips B, which are provided with a shoulder at their attached edge or are set out from the board A, as illustrated, to

serial No. 388,568. (no model.)

afford longitudinal guideways for thetype or print bearing slide C, which is provided on .its rear side at a suitable point with a tab or button D, whereby it may be readily adjusted. At the bottom of the board A a transverse strip E, of a similar construction to the strips B, is provided, whereby the downward movement of the slide C is limited. Upon the face or front side of the slide C, which is of a rectangular form, as shown, we provide at intervals blocks of type or print, which are numbered, respectively, 1, 2, 3, and 4, and are of a size and form tobe exhibited through the rectangular opening a when theyI are brought in alignment therewith.

In the present embodiment of our invention we `have illustrated four species of type or print-viz., pearl, indicated by 1; brevier, indicated by 2; small pica, indicated-by 3, and great primer, indicated'by 4-and we have found by experience that this number and series of species is well adapted to attain the end desired; vbut it is obvious that if desired a greater or l'ess number ot' species might be employed.

At a suitable point upon one of the guidestrips B with respect to the rectangular opening a, we providean index-markhand upon the rear side of the slide C,at suitable points with respect to the several species of type or print, we provide index-

marks

1, 2, 3, and 4, whereby it will be seen that the operator may stand at the back of the test device and bring any desired species of type or print into alignment with the opening d and before the patients vision by simply registering the number of such species with the mark b, before described.

By a device of the construction described it will be seen that an experienced optician or oculist by simply adjusting the slide C in the manner described may readily ascertain the strength or state of a patients eyes.

Having described our invention, what we claim, and desire to secure by Letters Patent, 1s

The device for testing strength of sight, consisting, essentially, of the face-board hav- A ing a sight-opening formed therein and guideways formed on the back thereof and also having an index-mark on its back at a suit- IOO able point with respect to the sight-opening, in combination with a slide adapted to move in the guideways of said face-board and Inarkupon the back of the face-board, sub- 1o stantially as and for the purpose set forth.

In testimony whereof We affix our signatures bearing species of type or print of different in presence of two Witnesses. degrees of neness upon its face. and indeX- marks upon its back at suitable points with respect to the several species of type on its faee,'the said index-marks on the slide being designed to be registered with the index- EDWARD CLAUDEL. LOUIS CLAUDEL. Witnesses:

A. P. ROUX, PERCY D. PARKS.