Abstract: A fluid flowmeter of the vortex shedding type. The vortex frequency is determined from variations in the internal reflectivity of a prism 16 mounted in the fluid and coupled to a light source 13 and to a detector/frequency meter 14 via an optical waveguide arrangement 15. Passage of a vortex adjacent the prism 16 causes a temporary change in the local fluid refractive index and hence a change in the intensity of light internally reflected by the prism.

Abstract: A continuous ink ribbon cassette for, for example, a serial printer in which a ribbon is kept in stacked loops in a vertical housing and is twisted on leaving and re-entering the housing so as to bring it into a vertical plan as it passes a print head. The ribbon leaves the housing through an opening at one end and passes round a vertical roller at the other end. After passing the print head, the ribbon is returned to the housing via a second vertical roller at the opposite end and an opening at the opposite end. The ribbon thus executes a figure 8 configuration and has the entire length of the housing in which to change its attitude from horizontal to vertical or from vertical to horizontal.

Abstract: A quartz tuning fork is provided which may be employed in several instruments for measuring the properties of fluids. The tuning fork may be employed, for example, in a gravitometer, a barometer, an altimeter or a temperature sensor.

Abstract: A vibration densitometer probe including an internal piezoelectric crystal, a canted vane, and an isotropic ring to support the vane.

Abstract: A device for controlling the spot elements of an optically controllable component in a facsimile recorder which permits a high writing speed with minimum circuitry. The plurality of spot elements of the controllable optical component are combined in n groups of m>1 spot elements each, the m spot elements of a group forming a partial line. The individual partial lines are energized successively in time, while their m spot elements are energized simultaneously, the respective n-1 nonenergized partial lines completely blocking the light flux.

Abstract: An optical fibre strain gauge arrangement is employed to take advantage of a so-called speckle effect. As used in a simple strain gauge, a coherent light source, e.g. a laser, launches light via a suitable launching device into a multimode optical fibre or fibre bundle. Due to slight differences in transmission times in the fibre or fibre bundle the light as received at a detector has a speckle pattern. If the fibre or fibre bundle is subjected to strain, the various transmission times are caused to change so that the speckle pattern shifts, the amount of the shift being a measure of the strain. This principle is usable in a vortex flowmeter where the vortices produced by a bluff body influence such a fibre arrangement. Further, when used underwater, passing ships and submarines may be detected. In a building, the arrangement may be used as an intruder detection system.

Abstract: Gross calorific content available from natural gas combustion determined from proportionality to molar oxygen demand in an apparatus including: provision for supplying gas and air at fixed, standard volumetric rates such that oxygen is present in excess; a combustion chamber employing swirled mixture introduction to effect complete gas burning; an oxygen sensor to detect deviation of combustion product oxygen content from an optimum setpoint value; an electrolytic hydrogen (oxygen) generator, the output of which adds to the gas and air mixture prior to combustion; and electronic control circuitry to maintain setpoint through regulation of an electrolysis current. Said current, or its control signal, also serves as a direct electronic meter of the generated species. Thus, through calibration, a measure of oxygen demand and calorific value is provided.

Abstract: A liquid level system having a bellows biased with a spring having a constant to add a variable force to a water column of a magnitude substantially equal to a loss in pressure resulting from an increase in water temperature. Such a system may also have high and low pressure connections to corresponding bellows and springs. The reference column may also be large in comparison to the remainder of the capillaries.

Abstract: A flue gas analyzer including a probe module to condense water vapor, a sampling module, and a titration module including an SO.sub.2 scrubber, a thermal oxidation device and a coulometric titrator.

Abstract: A ball valve having a cylinder slidable in a port. The cylinder has a lip which is pressed, by a spring, against a spherical surface surrounding a passage through the ball. A sleeve is slidable to a position over the cylinder, the sleeve having an annular groove adjacent the lip and a first seal therein. The sleeve has a portion contiguous to the cylinder at the end thereof opposite the lip, a second seal being provided between the housing and the sleeve portion. If C is the inside diameter of the lip, if B is the outside diameter of the length of the cylinder having the groove, if A is the outside diameter of the sleeve portion, if A>C, and if C>B, the valve will seal for flow in either direction or for zero flow all at, say, 3000 psi.

Abstract: A differential pressure unit having overrange valves loosely mounted on a valve stem connected between the ends of a respective pair of movable bellows ends. A pair of spiral range springs bias both valves toward open positions. The valves include annular elastomers bonded to the edges of the apertured discs. The apertures in the discs act to allow the elastomers to seat and to unseat without causing lock-up. The discs are retained between plates and snap rings.

Abstract: Semiconductor transducer devices are provided, some being formed from a single crystal and having a flexible portion which is vibratable. Also a multi-element is disclosed which is a body including mechanical semiconductor resonator. The body has a transverse valley across its width. A comb-like array of flexible silicon cantilevers extend from one end of the body. Each cantilever is adapted to respond to a periodic force such that each has a different vibrational frequency. An alternative embodiment includes an accelerometer having a block with a three cantilever array with a semiconductor filament fixed in tension between each adjacent pair. The middle cantilever is longer than the other two. A further alternative employs elements to support a crystal at two nodal points of vibration.

Abstract: A 4-way, 2-position pilot valve having two ball valves seatable at approximately the same time without a precise spacing.

Abstract: A silicon transducer including a silicon frame with one or more lands extending from a diaphragm or the like. The lands are interconnected by two thin strips formed integrally with the lands. The strips are essentially the transducer. The transducer is constructed by etching a boron doped wafer with a mixture of catechol, ethylene diamine and water.

Abstract: A vibration viscosimeter having a resilient wire loop to be vibrated and an electrical drive therefor. The energizing signal for the drive is alternately kept 30 degrees lagging and 30 degrees leading the vibration or vice versa. Viscosity may then be computed as a function of the signal periods and six constants.

Abstract: A butterfly valve having a split sealing ring in a groove in the interior of the passageway therethrough, the sealing ring having mating ends of a tongue and groove construction or the like.

Abstract: A machine to assemble electrical contact retention clips in an insulator including an indexing turret having jaws, a jaw operator, a clip carrying strip feed, a clip loading and clip shear-from-strip mechanism, an X-Y table driven by a conventional microcomputer numerical control to position the insulator and a plunger reciprocable through the jaws to insert clips into the insulator holes.

Abstract: A vibration densitometer probe assembly including a web partly covering a bore in an annular support, the web having a central hole therethrough, a probe shaft sealed through the hole, and a compressed packing in the bore bearing upon the probe shaft.

Abstract: A vibration densitometer having a magnetostrictive drive with a coil, and a crystal pick-up. A loop circuit including a driver amplifier provides the coil with current which leads the crystal voltage by 90 degrees for maximum efficiency. The driver amplifier is unusually small, inexpensive and accurate.