Abstract: Disclosed is a wheel having two staggered rows of surface-gripping, radially-yielding feet. When the wheel encounters an obstacle, a spring compresses, thereby permitting the feet to deflect and absorb shock that would have otherwise been imparted to the vehicle. While travelling on a smooth surface, the feet deflect an amount depending upon the load carried by the wheel. Since the shock absorbing spring is recessed in a cavity in the foot, the distance that a foot can deflect is increased.

Abstract: An oil filter cartridge comprising filter discs and separator discs stacked alternately, the separator discs having inlet and outlet chambers walled in by the contiguous filter discs. The filter discs have inlet ports in registration with the inlet chambers for introducing unfiltered oil therein. The separator discs are provided with slots registering with the inlet ports of the filter discs. These slots, in combination with the adjacent inlet ports, provide enlarged inlet orifices which are not readily blocked by swelling of the material of the separator discs due to water-contaminated oil.

Abstract: A low loss buffered optical waveguide fiber is described. An optical waveguide fiber is coated with a first layer of high modulus material applied to the exterior longitudinal surface thereof. Thereafter, a second layer of low modulus plastic material is disposed over the layer of high modulus material. The ratio R.sub.i /R.sub.o of the radii of the first and second applied layers is selected to minimize the microbending loss.

Abstract: An optical fiber connector comprising a first resilient member having elongated grooves in the surface thereof into which fibers to be optically connected are disposed end-to-end. A second resilient member is urged against that portion of the fibers opposite the first member, thereby causing a slight deformation of the second member and the groove forming walls. The substantial equilibrium of forces applied to each pair of fibers by the resilient members causes their axes to become aligned. A longitudinal force applied to each fiber urges the endface thereof into contact with the endface of the fiber that is to be connected thereto.

Abstract: An optical fiber connector comprising a first resilient member having an elongated V-shaped groove in the surface thereof into which two fibers to be optically connected are disposed end-to-end. A second resilient member is urged against that portion of the fibers opposite the first member, thereby causing a slight deformation of the second member and the slot-forming walls. The substantial equilibrium of forces applied to the two fibers by the resilient members causes their axes to become aligned. The preferred embodiment is capable of connecting corresponding fibers of two bundles and also includes means for positioning the endfaces of the fibers of one bundle in virtual contact with the endfaces of the fibers of the other bundle.

Abstract: An antireflective layer is formed on a surface of a body of phase separable glass by heat treating the glass to cause it to become separated into at least two distinct phases of different solubility. A surface of the body is subjected to a leaching solution which preferentially leaches at least the most soluble phase, leaving a surface layer consisting of a skeletal structure that comprises the least soluble phase. The leaching solution preferaby contains an acid which etches the skeletal structure which becomes so modified that the film exhibits an effective refractive index gradient thereacross, the film therefor exhibiting antireflectance properties over a wide band of wavelengths.

Abstract: An optical fiber junction device for permanently coupling a pair of optical fibers with a third optical fiber. The end portions of the pair of fibers are fused together in side-by-side relationship so that their endfaces are coplanar, the cross-sectional area of this structure decreasing toward the endfaces of the pair of fibers. The endface of the third fiber is fused to the endfaces of the pair of fibers.

Abstract: A porous layer is formed on a surface of a body of phase separable glass by heat treating the glass to cause it to become separated into at least two distinct phases of different solubility. A surface of the body is subjected to a leaching solution which preferentially leaches at least the most soluble phase, leaving a surface layer consisting of a skeletal structure that comprises the least soluble phase disposed on a substrate of phase separated glass. The glass body is then subjected to a second heat treatment at a sufficiently high temperature that the phase separated glass substrate is caused to become homogeneous, the porous surface layer remaining substantially unchanged. The resultant homogeneous glass substrate is more chemically durable than it was in the phase separated state.

Abstract: Disclosed is a resistor comprising a nonconductive substrate on which is disposed a rectangularly-shaped coating of resistive material having a negative TCR. Oppositely disposed along the longer sides of the coating is a pair of elongated, parallel strips of resistive material having a positive TCR. Electrical connection is made to the opposed ends of the coating and to an end of each strip. The strips and electrical connections are so disposed that at low temperatures, current flow is predominantly across a relatively wide, short path in the coating between the strips, and at higher temperatures, current flow is predominantly along a longer, narrower path in the coating which is parallel to the strips.

Abstract: A coupler disposed between two optical signal transmission lines for extracting from the first transmission line a fraction of the energy transmitted thereby and for injecting an input optical signal into the other transmission line. The first transmission line is coupled to the input of a first mixer rod, the output end of which is connected to the input end of a second mixer rod by a first optical waveguide bundle. A second optical waveguide bundle, which is also connected to the output of the first mixer rod extracts a portion of the energy at the output end of the first mixer rod and couples it to output means. An input optical signal is coupled by a third optical waveguide bundle to the input end of the second mixer rod, the output end of which is coupled to the second transmission line.

Abstract: A method and apparatus are described for permanently splicing glass optical fibers. The fibers are aligned colinearly, and their endfaces are brought into contact. An electrical arc discharge is generated at the junction between the fibers and is moved along the junction to ensure complete fusing of the fiber endfaces. Best results are obtained by first applying only enough heat to the fiber junction to cause the fibers to adhere to each other without forming a good optical connection, and thereafter, increasing the arc current to a value sufficient to cause complete fusion of the fiber endfaces.

Abstract: Method and apparatus for staining biological specimens by forming a film of staining reagents on the surface of the specimen containing slide. Heating means raises the temperature of the staining reagents on the slide. The temperature of the reagent film is determined, and a feedback signal to the heating means accurately maintains the temperature of the film within a predetermined range.

Abstract: An apparatus for severing the ends of a plurality of parallel optical fibers so that the endfaces thereof are relatively flat, are substantially perpendicular to the fiber axes and are relatively coplanar. The fibers are bent over an arcuate surface and are slidably clamped between the flat surfaces of two pieces of rubbery material. The clamp is urged by a spring in such a direction that the fibers are in tension. After one fiber is scored and breaks, the clamp automatically slides along the remaining fibers until the clamping force on those fibers is sufficient to prevent further sliding. The fibers are individually severed in this manner.

Abstract: Apparatus for controlling the temperature of an open liquid body when actual measurement of that temperature is not possible. A thermal analog of the liquid body, which is exposed to the same heating or cooling source as the liquid body, is incorporated into a sensor which provides controlling feedback to the heating or cooling source. The sensor, which is disposed in the atmosphere which surrounds or flows by the liquid body, includes a dry element and a wet wick, body of which are in thermal contact with a temperature sensing element. The dry element senses the temperature of the atmosphere and the wet wick has a cooling effect on the sensing element that is related to the rate of evaporation of liquid from the body. This sensor is advantageously employed in a system for regulating the temperature of a reagent film on a microscope slide.

Abstract: An optical waveguide for use in an optical communication system employing a broad spectral source. Mode coupling is present in the propagation of optical signals in the waveguide, and the parameters of the waveguide are such that pulse dispersion produced by the finite spectral width of the source is minimized by utilizing the mode coupling to substantially cause cancellation of dispersion which is linear with respect to waveguide length and which is caused by the mode independent material dispersion and by the mode dependent waveguide dispersion.

Abstract: A flow metering apparatus comprising an elongated vortex generating element disposed transversely in a stream of fluid to produce on opposite sides thereof vortices which are shed in alternating fashion and a sensor disposed downstream of the generating element and aligned therewith in such a manner that the vortices alternately pass along opposite sides of the sensor. The sensor comprises an elongated, cylindrically shaped support having two high TCR resistive films longitudinally disposed on the surface thereof which faces the vortex generating element. This combination of vortex shedder and sensor produces a strong, highly reliable electrical signal.

Abstract: A system wherein a magnetic tape is divided into a plurality of data storage blocks, each of which is preceded by a unique block marker. A phase encoder and phase decoder associated with the read/write head are connected by a data control circuit to a computer. As the head scans the block marker, the phase decoder supplies the computer with the block marker data via the data control circuit. Immediately after a predetermined block marker has been read, the computer provides the data control circuit with a write-signal and makes available a byte of parallel data to be written on the tape. The data control circuit includes an erase latch activated by the ongoing transition of the write-signal for providing the phase encoder with an erase-signal which causes the first byte on the magnetic tape following the block marker to be an erased gap.

Abstract: A sensing element for measuring fluid flow comprising an elongated cylindrically-shaped support on which is disposed two resistive films having high TCR values. The support is symmetrical about a plane parallel with the direction of flow, and one of the resistive films is disposed on each side of that plane. The films are less than 10,000 A thick, thereby possessing a high ratio of surface area to thermal mass. These films are quickly cooled by pressure variations accompanying the generation of vortices in the fluid stream, and they are therefore capable of operating at high frequencies.

Abstract: Disclosed is an optical system for dividing a single optical image into two or more geometrically identical images which are contiguous and coplanar in space and which have the same magnification. A beam splitter and a fold mirror divide the original optical path into a first optical path which forms an image from light passing through the beam splitter and a second optical path which forms an image from light reflected from the beam splitter and fold mirror. A displacement block is inserted into the second optical path to move the image plane away from the fold mirror and cause the images formed from the first and second paths to become coplanar. The displacement block is mounted so that it can rotate about two axes so that one image can be positioned precisely adjacent to the other image. By forming the block from two glasses having different absorption characteristics light in the second path is adjustably attenuated.

Abstract: A fluorine containing silicate glass substrate is heated to a temperature sufficiently high to permit fluorine to out-diffuse from the surface thereof. A surface region is formed having a gradient fluorine concentration in a direction perpendicular to the substrate surface, the region of lowest fluorine concentration having the highest refractive index. The resultant device is capable of functioning as an optical waveguide.