Am improvements in ophthalmoscopes / [Arthur William Down].

  • Down, Arthur William.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Am improvements in ophthalmoscopes / [Arthur William Down]. Source: Wellcome Collection.

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    JNTO 5517 A.D. 1892 Daie of Application, 21st Mar., 1892—Accepted, 4th June, 1S92 COMPLETE SPECIFICATION. An Improvement in Ophthalmoscopes. , We Arthur William Down and Hubert Vincent Down bo* of Nos. 5 & 7 St. Thomas s Street Borough m the County of London trading together in partnership as Surgical Instrument Manufacturers under the style or firm of “Down Bros.,” and Richard Henry Ferrier of 56 Beresford Street 5 Walworth in the County of London aforesaid Optical Instrument Maker do hereby declare the nature of this invention, and in what manner the same is to be performed, to he particularly described and ascertained in and bv the following statement:— ' 10 15 20 The invention is an improvement upon what is known as Morton s ophthalmo¬ scope and consists m the novel form of link lens holder. It is constructed to hold the lens and for the additional and novel purpose of indicating the power of a lens thus dispensing with time wheels or other means of shewing the power of a lens when presented at the sight aperture thereby reducing the number of working parts in an ophthalmoscope and rendering the instrument less liable to get out ol older, and is accomplished as set forth in the following description and drawing accompanying this Specification :— 8 In the drawing, Figure 1 is a plan of the tray links and driving wheel of an ophthalmoscope the tray back or upper surface plate is removed to show the links in position. 1 he links are represented by thirty circles and are not attached to each other but work freely between the two surface plates. They are guided in their course by the link race E E The. large# circle D. is a milled wheel fixed to a small steel wheel C, whereby the chain of links is set in motion. F. indicates the position in the uppei suiface plate of the reading aperture and Gr. of the sight aperture Figure 2 is a section of Figure 1. at the line A. B.—E. E. is the link race or tray with the links removed. Figure 3. is the complete link lens holder. K. is the lens. J. the cell holdino- the same and H. the wing which carries the number or sign of lens power of a lens a given number in advance. ' 1 Figure 4. is a section of Figure 3. with lens. A wing of metal oi othei suitable material is attached to each lens holder. It is so fashioned in shape as to permit of the series of lenses and wings easily tiavelhng’ in the link lace or tray both in a straight line or revolving in a circle and is of sufficient size for a figure, or figures, or sign or signs indicating the 35 power of a lens to be placed upon it (see Figure 3). The numbei oi sign placed on the wing* is that indicating the power of the lens a given number in advance so that when lens of power No. 1 occupies the position at the sight aperture (see G Figure 1) its number which is attached to a lens a few intervals from it appears at the reading aperture (see F. Figure 1). The leading aperture is placed away from the sight aperture for convenience and so as not to obstruct the vision. 25 30 40 45 Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed we declare that what we claim is The novel application to ophthalmoscopes of a wing attached to a revolving link lens holder to indicate the number, sign, or power of the lens in position. Dated this 21st day of March 1892. For the Applicants, A. MOZLEY STARK, 62, Strand, W.C., Solicitor. London : Printed for Her Majesty’s Stationery Office, by Darling & Son,Ltd.—1S92 [Price 8d.]