GB725874A - Improved ophthalmic measuring device - Google Patents

Abstract

725,874. Ophthalmic apparatus. BELGARD, A. B. May 20, 1953, No. 14233/53. Class 97 (1) An ophthalmic measuring device for attachment to spectacles or spectacle frames comprises a housing, a pair of carriers slidably arranged thereon each carrying a depending slide provided with a scale for alignment with the pupil of one -eye, and a pair of posts depending from the housing between said carriers, at least one of the posts being movable, independently of the carriers towards and away from the other post. As shown, the apparatus comprises a tubular member 10, Fig. 1, having a slot 12 from which projects a portion 13 of a slide carrying scales 14 and also supporting, within the housing gear 17, Fig. 10, pivoted at 16 to the slide and engaging on one side teeth 18 fixed to the member 10 and, on the other, teeth 20 carried by a member 19 slidable longitudinally in the tube 10 and normally pressed by a spring 43 against an adjustable stop 44. Attached to the slide 19 is a finger grip 21 and a depending member 25 carrying an inturned point 27 for engaging the inside of a lens rim and a pin 31 for alternative engagement with the rim 29 when this latter is occupied by a lens. A post 24 is fixed to the tube 10 and has similar members 27, 31 for engaging the other rim 29. Sliding on the tube 10 are carriers 32 moving against the scales 14 and having at the rear vertical guides in which measuring slides 39 may move. In operation the grip 21 is moved laterally to space the posts 24, 25 apart, a grip 23 fixed to the tube 10 being provided to facilitate this operation, and the points 27 are brought into engagement with the inner portions of the rims 29 of the spectacle frame. If the latter has lenses the apparatus is held thereon by clamps 46, 47, Fig. 1, and the pin 31, Fig. 11, brought into engagement with the lens rim or members on the posts 24, 25 brought into engagement with the screws holding the lenses in the rims. This lateral adjustment of the post 25 relative to the post 24 produces, through the gears 17, a corresponding lateral movement of the slide 13. When so adjusted, a scale 55, Fig. 1, indicates the distance between the lens rims, the carriers 32 may be adjusted laterally until the slides 42 are opposite the eyes of the wearer when the distances of the eyes from the centre of the nose may be read from the scales 14 whilst scales on the slides 39 permit measurement of any vertical distance between the eyes. An enlarged portion 42 of the slide 39 may be used to indicate the width of vision of the wearer.