Abstract: The melt pressure transducer is preferably for use in pressure measurements associated with an injection molding machine, and is designed to be mounted inside a mold to measure cavity pressure directly. In addition to being small in size, the transducer is also adapted for high cycle life. The transducer utilizes an internal filler rod for temperature compensation and, also, to reduce liquid volume rather than a capillary. The strain gauges are secured to opposing flats of the housing to provide a pressure-ranged section. The housing is in the form of a thick-walled cylinder with the flats forming the sensitive areas. Further, a unique fill and seal technique is described for charging the transducer and, at the same time, pre-stressing the coupling diaphragm.

Abstract: Sensing and electrical-signal characterization of fluid pressures is effected by a miniature precision transducer manufacturable at low cost from a combination of a pair of sub-assemblies, one of which consists of a single-piece metal transducer element having a flanged body with a blind-hole port leading from a mechanical pressure fitting to the inner side of a transverse thin diaphragm which forms the blunt flat end of the body except for a bonded covering of both the machined outer side of the diaphragm and its coplanar annular rigid rim by a foil-type rosette strain gage bridge array and its layer of supporting insulation.

Abstract: Each of two pairs of electrical-resistance strain gages which are to make up a measurement bridge for a beam-type load cell is fashioned as a composite wherein two spaced-apart grids of foil-type parallel elongated filaments oriented and functioning as strain gages are made of material promoting a strain gage factor effective to compensate for elastic modulus change of the beam material as temperature varies over an expected range.

Abstract: Strain-gaged transducers sensing weight of a storage tank in an electronic weighing system also provide the sole structural suspension for the tank upon its underlying support. The transducers are arrayed about a position which is central to the tank, and each is mechanically linked with it via a height-adjustable lateral-expansion assembly including a clevis with its horizontal shaft slidable longitudinally along an axis aimed at the center position and with universal jointing about mutually-perpendicular axes. Misalignments and expansions are accommodated, without impairing accuracy of weight measurements.

Abstract: A strain-gage transducer incorporating a plurality of electrical-resistance strain gages coupled together in a bridge network is caused to remain zero-balanced under varying-temperature conditions by way of dual-resistance foil-type unit interposed at one of the output corners of the bridge with its two like foil-resistance elements occupying adjacent arms. The foil material is selected to exhibit a resistance change with temperature representing a factor which enables a target room-temperature measurement to be calculated once a rate of change of bridge output with temperature has been determined from measurements taken while the unstrained transducer is held at different temperatures. Relatively broad surfaces of the foil elements are left exposed, and the unit of which they are a part is so disposed in relation to the transducer structure that the exposed foil is accessible for controlled erasure-type abrasion which will bring about the target measurement and attendant compensation.

Abstract: Precision strain-gage transducers of low-cost construction, which lend themselves well to expression in the form of protectively-enclosed miniature load beams, are developed from sensing elements fine-blanked from wholly flat thin metallic sheet stock, the shaping and dimensioning of critical strain-responsive portions being controlled by the fine-blanking of both inner and outer edges of the element. Versatile mounting and loading provisions are conveniently associated with the element by way of simple openings formed laterally of the strain-responsive portions, and protective enclosure of sensitive strain gages and the strain-responsive portions is achieved by the transverse build-up of the element with stamped sheet-stock flanges affixed and sealed to it at spaced positions and to ends of a surrounding tubular bellows.

Abstract: Electrical-resistance strain gages, particularly those of foil construction, are advantageously pre-packaged as conveniently-manipulatable and protected sub-assemblies in which the metal gage grid and its tabs are sandwiched between a flexible tape coated with a tacky adhesive and a partly-cured thin layer of fiber-reinforced resin, the resin layer and exposed portions of the adhesive-coated tape in turn being protected by a removable polytetrafluorethylene cover sheet; bonding of the gage to a measurement specimen is achieved without conventional cementing by removing the cover sheet, abutting the resin layer with a selected surface of the specimen, heating the layer while pressing against the tape to force the gage partly into the layer and to force the layer against the specimen surface, and stripping the tape after the resin has cured, thereby leaving the gage in a firmly-bonded close proximity with the specimen surface, separated therefrom only by a thinned layer of fiber-reinforced resin which also lock

Abstract: Vehicle-detection apparatus, for installation at highway toll-booth, parking-area, and like sites, includes elongated thin-strip electrical switching sensors disposed near a road surface and oriented transversely to traffic directions, for responses to tire-transmitted loadings, the switching sensors each being in the form of a pair of narrow highly-elongated flat conductive strips, at least the upper one of which is springy and both of which are cartridged in a minutely-spaced substantially parallel relationship within a shallow open-topped flat-bottomed rigid channel member, the minute spacing being maintained by plastic insulating tape sandwiched between the strips only near their edges; the plural sensors are cast into a tough but somewhat flexible plastic mass in side-by-side relationship atop a stiff backing plate, with the upper strip being parted from the mass by a thin plastic sheathing, and the top surface of the cast assembly is rendered non-skidding by way of abrasive particle embedments.

Abstract: An electrical alarm system, which responds to improper and/or unsafe loading of a fork-lift truck or other load-sustaining apparatus equipped with a suitable sensing transducer, is controlled by a high-gain electronic differential switch whose comparisons of reference and sensing-transducer electrical signals are uniquely improved by a combination of: (a) unidirectionally-positive feedback which produces a dynamic transient hysteresis effect; (b) steady-state feedback or hysteresis which prevents false triggering of the system by ambient noise and vibration; (c) a regulator and electrical interference suppression network; and (d) low-level high-frequency partial filtering of oscillations in the waveform of sensing-transducer output signals. Fail-safe system operation is assured by network connections and output actuations which prevent the handling of loads when system cabling is disabled, as well as when overloading is sensed.