Abstract: An ophthalmic glass lens can be prepared by exposing an alkali metal silicate glass to an ion exchange process in which the glass is chemically strengthened by an exchange of potassium ions for sodium ions in the surface layer of the lens at a temperature either above or below the strain point of the glass. The glasses prepared are essentially free of alumina, have adequate strength and substantially increased depth of pentration of the neutral zone even when up to about 6 percent lime is utilized in the preparation of the glass. The effect of lime as a diffusion-retarding agent during the ion exchange process can be overcome (1) by use of an appropriate amount of zinc or magnesium oxide or mixtures thereof so as to maintain an adequate rate of diffusion during ion exchange or (2) by preparation of the glass essentially free of alumina.

Abstract: Apparatus having a headstock and tailstock between which a shortened fiber optic image-inverter is formed by twisting and axially compressing a heated bundle of light-conducting fibers held by endpieces respectively supported in said headstock and tailstock; said endpieces being axially rotatable, one relative to the other, for twisting said bundle and moveable, one axially toward the other, for compression of said bundle.

Abstract: A plurality of optical glass cores of selected refractive index and dimension are clad with a first glass of lower refractive index providing substantially total internal reflection within the cores. The clad cores are then clad with a glass displaying a lower viscosity than either the core or the first cladding and fused into a final assembly. The cross-sectional area of the second core cladding is selected to provide a minimum free space within the fused assembly.

Abstract: A glass blade is produced from a preform of insoluble glass having a sharp edge encased in soluble glass. The encased preform is heated and drawn to the reduced cross-sectional size desired of the glass blade, cut transversely to length and leached for removal of the soluble glass and exposure of its sharp edge.

Abstract: A conventional pressure cuff is attached to a living test subject. First means are provided for changing pressure in the cuff and thereby applying pressure to the subject. Second means communicating with the cuff are provided for measuring a quantity proportional to a time-dependent fluctuating component representative of pulsatile pressure within a blood vessel of the subject, the second means having a frequency response of at least about five times the subject's pulse rate, whereby the fluctuating quantity is proportional to amplitude of pulsatile pressure. The maximum value of the fluctuating quantity is determined as applied cuff pressure is changed. Third means are provided for determining when the fluctuating quantity is about one-half its maximum value for applied cuff pressure greater than the pressure applied when the maximum value occurred or resulted.

Abstract: Making glass microchannel plates by drawing bundles of large numbers of glass tubes sufficiently to reduce the cross-sectional sizes of openings through the tubes to desired microchannel size with minimal distortion of original tube shape and wall thickness in resulting assemblies. Drawing is accomplished with no less than two separate steps; a first step being effected with large pulling force and minimal heating and a second step effected with relatively small pulling force, heating to relatively high viscosity and rapid drawing for short exposure to heat.

Abstract: A glass electron-multiplying microchannel plate of lead-containing glass is mounted within a supporting rim of another glass. The plate is connected to the rim with a relatively low melting temperature solder glass and the rim is slotted at a number of points about its periphery. The slots extend completely through the rim and partially into the connecting solder glass to protect against fracturing of the assembly during treatment thereof in reducing atmospheres.

Abstract: A centrifugal casting mold and mold clamping system adaptable to mass-production technology including a tapered multiple part mold and similarly tapered sleeve within which the assembled mold is insertable for resin filling and centrifuging.

Abstract: A microscope condenser of the Abbe type has the optical characteristics of the biconvex singlet followed by the convex-plano singlet improved by making the first surface of the biconvex singlet aspherical. The aspherical surface substantially reduces spherical aberration and coma as well as pupillary aberration of the condenser.

Abstract: Apparatus for making fused bundles of glass fibers including a rectangular support for receiving the fibers to be fused, quadrangularly related plungers, one movable toward and away from each of the sides of said rectangular die, a number of high pressure cylinders arranged to force said plungers simultaneously toward and against the die and a heating furnace enclosing the die and adjacent portions of the plungers. The plungers and furnace are supported independently of each other upon a common base of the apparatus whereby the furnace is unaffected by forces applied to the plungers and die.