Abstract: In order to make optimum use of the available transmission channels in an information transmission system, such as a trunked mobile ratio transmission system, where a number of uncoordinated users may wish to signal to a central control point in addition to using the channels for another purpose, the central control point monitors the channels and, when a channel is or becomes free, sends a command signal on that channel. When a user who is waiting to signal receives the command signal he chooses one of a predetermined number of immediately following time slots in an effectively random manner and sends his request in that slot in digital message form. The central control point sends an acknowledgement in the next time slot if and only if it receives the request in an error-free manner. If a user does not receive such an acknowledgement in response to the transmission of such a request he tries again when he receives the next command.

Abstract: It has been determined that 180,000 dalton molecular weight carcinoembryonic antigen has an antigen site which is not shared by other molecular weight carcinoembryonic antigens, which are released by colorectal carcinoma. A hybridoma antibody specific for the 180,000 dalton molecular weight carcinoembryonic antigen is described.

Abstract: In order to form a first-come first-served queue in an information transmission system employing a common transmission channel when several transmitters of the system try to gain access to the channel when it is already occupied, without employing a further transmission channel to a point at which an account is kept of the order in which the various transmitters request access, each transmitter which tries to gain access in these circumstances is caused to delay after the channel subsequently free before it actually accesses the channel, this delay being inversely proportional to the time the corresponding transmitter has waited. Thus the transmitter which has waited the longest gains the channel first and causes the other waiting transmitters to continue to wait.

Abstract: A monitor for logic circuits detects loss of redundancy within the monitored circuit and designates that portion thereof which is out of service. Loss of redundancy is detected by sensing the passage of normal load current, or a portion thereof, through shunt current paths; the occurrence of such current flow coupled with the direction of flow uniquely determining the portion of the logic circuit which is out of service. In a preferred form of the invention, a low ohmic valued resistor is connected in each shunt current path. Upon loss of redundancy, a voltage signal generated across at least one such resistor, is applied to one or more parallel connected amplifiers responsive to the signal to activate corresponding switching circuits and audio/visual indicators.

Abstract: In an acoustic wave device having a pair of spaced apart reflectors forming a resonant cavity, each reflector consists of an array of parallel reflective elements. At least one of the reflectors is weighted not by simple withdrawal of reflecting elements from a nominal uniform array but instead by substituting reflective elements of the uniform array with elements providing both net-zero reflection at required positions and also at least partial compensation for the velocity perturbation which would be produced by such simple withdrawal. Such weighting may be used to suppress the side lobes of the reflector response and hence improve the stopband performance of the acoustic wave device and, for example, a coupled resonator filter in which that device is incorporated.

Abstract: Vibration of a rotating disc is dampened by means of a pair of weights which respectively lie in inclined tracks and are held against the opposite faces of the disc by the force of gravity.

Abstract: A planetary friction drive includes a plurality of balls which are driven about a frusto-conical outer race by an inner driving surface made up of a pair of jaws which are spring biased toward one another into frictional engagement with the balls, and the drive ratio is adjusted by axially moving the inner driving surface relative to the outer race.

Abstract: An acoustic wave resonator device comprises a substrate carrying a pair of spaced apart reflectors forming a resonant cavity that supports only three adjacent distinct resonant mode frequencies. An interdigital transducer is disposed on the substrate between the reflectors and includes an array of electrodes symmetrically arranged relative to a central point of the cavity to form a plurality of electrode pairs with the electrodes of each pair equally spaced on opposite sides of the central point. The central point of the cavity coincides with a node or an anti-node of the standing wave. If the two electrodes of each electrode pair are connected to the same terminal then the transducer has zero net coupling with one set of alternate modes of the cavity, whereas if said two electrodes are connected to opposite terminals then the transducer has zero net coupling with the other set of alternate modes.

Abstract: An acoustic wave resonator device includes two pairs of coupled spaced apart reflectors which define two resonant cavities. The two cavities are each provided with two interdigital transducers which provide intercavity coupling. Additional reactance coupling between the transducers in one cavity combines with the equivalent cavity reactance to provide series or parallel resonance at a selected pole frequency.

Abstract: An acoustic surface wave device employs a substrate structurally orientated to enhance the propagation of acoustic surface skimming bulk waves. Multiple reflections from opposed end faces of the substrate establish an acoustic surface skimming bulk standing wave at a predetermined frequency. An interdigital transducer couples to the standing wave. A plurality of devices may be intercoupled to provide a bandpass filter.

Abstract: The present invention provides a slide rule for use by physicians, pharmacists and other medical or hospital personnel in determining and computing dosages to be administered by hyperalimentation. Total calories in the dosage, as well as final percent concentrations of base components and nutrient solutions in the dosage, may be determined.

Abstract: The input and output transducers associated with an acoustic surface wave resonator, or with respective acoustically coupled cavities, are split into staggered pairs. Furthermore they are located with respect to the standing wave pattern(s) and connected to input and output terminals in such manner as to suppress the response of the output transducer to travelling waves received directly from the input transducer and reduce the stopband level of the device associated with that response.

Abstract: This invention concerns a method for the removal and recovery of synthetic polymers from solvents using dropwise impingement of a solution of the polymer in a solvent upon a mobile capillary inactive liquid surface to volatilize and recover the solvent, leaving the previously dissolved synthetic polymer on the surface of the capillary inactive liquid. The solvent is recovered by condensation for reuse and the polymer is recovered from the surface of the liquid by mechanical means.

Abstract: An improved two printing step process for reproducing visual subject matter including the making of a secondary printing plate with a positive image random pattern screen and printing a substrate sequentially and in registry with the secondary printing plate and a master printing plate made with a conventional half tone screen. The random pattern screen is a positive image phototransparency having a large plurality of irregularly shaped highlight areas and constrasting shadow areas per square inch, an optical density from about 0.17 to about 1.6, a contrast factor from about 0.75 to about 1.5 and a transparency factor from about 0.25 to about 0.60. The random pattern screen is made from a transparent plate having light disruptive projections on its surface. A negative and a positive phototransparency of the transparent plate are made while controlling exposure and developing conditions to produce a positive image screen having the desired characteristics.

Abstract: A tire and wheel rim assembly wherein the wheel rim includes adjacent to at least one bead seat a circumferentially extending groove and the tire bead has a radially and axially projecting extended toe portion which is axially and radially located within said groove. The toe is flexible in a direction substantially perpendicular to its length and substantially rigid in the direction of its length and provides an effective bead lock to retain the tire bead in position on the rim.

Abstract: An ejector mechanism associated with the punch or punches in a header, operable to free the work blank from the punch after a heading blow so that the blank may remain in the die for a further forming blow, the mechanism including timing means to insure actuation of the ejector at the moment when the punch starts its withdrawal movement, as well as clearing of the ejector to prevent transmission of a load to the ejector mechanism on the heading blow.

Abstract: Electrical inductive apparatus cooled and electrically insulated by a vaporizable liquid dielectric having a boiling point within the normal operating temperature range of the apparatus. When the electrical inductive apparatus is at ambient temperature, the liquid dielectric completely fills the enclosure providing electrical insulation for the electrical members. As the temperature of the apparatus increases towards its normal operating range, the liquid dielectric is gradually withdrawn into a reservoir until, at the normal operating temperature, only a quantity of liquid dielectric sufficient to completely cover the electrical inductive apparatus remains in the enclosure. In response to a temperature decrease, the liquid stored in the reservoir is gradually returned to the enclosure thereby maintaining a constant level of dielectric strength between the electrical members.

Abstract: An electrode structure within the cavity of an acoustic surface wave resonator, e.g. an interdigital transducer or a multistrip coupler, has two sections separated by an odd integral multiple of a quarter wavelength of the standing wave in the cavity and located with respect to the center of the cavity so that all the electrodes are midway between a node and an adjacent antinode of the standing wave. Distortion of the resonator response due to reflection by the electrodes of the transducer or coupler is suppressed by this arrangement.

Abstract: A surface acoustic wave band-pass filter comprising a piezoelectric substrate having on one surface first and second SAW resonators tuned to the same frequency and coupled together. An input transducer is coupled to the first resonator and an output transducer is coupled to the second resonator. Each resonator is preferably formed by two spaced apart aligned grating reflectors and the two resonators are preferably coupled by an array of discrete parallel metallic strips extending between the two cavity resonators.

Abstract: A single hand tool for removing and applying the springs on automotive brake shoe assemblies includes at one end a member for removing and attaching retainer discs on the hold-down springs and also for removing the shoe-to-anchor springs, and at the other end a spring operated mechanism for attaching the shoe-to-anchor springs to the anchor pin of the brake assembly.