Abstract: A system is disclosed for intelligently providing suggestions for solving problems encountered during installation and testing of complex electronic circuitry. A plurality of first outputs provide indications of non-selectable conditions of the system, such as conditions related to power supplies. A plurality of second outputs provide indications of conditions of signals coupled to the system, and a plurality of third outputs provide indications of selectable parameters, such as switch positions. These indications and conditions are monitored for incorrect conditions and are polled in an order determined by importance of the condition with respect to operation of the system. Responsive to an incorrect condition or indication being polled, the polling process is halted and a message is generated indicating how the incorrect condition or indication may be corrected.

Abstract: A temperature compensated video transmission system including a D.C.-video frequency amplifier for supplying a computer monitor wherein the operating bias for two opposite polarity type transistors are directly coupled collector-to-base, and bias to this coupling is provided through the base-emitter junctions of two serially connected transistors, the base and collectors of these transistors being directly coupled, whereby D.C. drift, with temperature, of the amplifier is prevented.

Abstract: This invention relates to circuitry for extending TTL signals from a computer to a remotely located monitor and keyboard and which uses a first signal conditioning circuit proximate the computer to generally reduce amplitude of the video signals and bias them to a selected potential, after which the signals are applied to discrete conductors of an extended cable. The cable, in three embodiments described herein, may be up to 250 feet, 400 feet, or 1,000 feet. A second signal conditioning circuit at the monitor and keyboard end of the cable receives the attenuated signals and utilizes a threshold or pair of thresholds to effect reconstruction of the video signals prior to inputting them to the monitor. Significantly, amplitude reduction or attenuation of the video signals generally reduces high frequency video noise appearing on the keyboard clock conductor of the cable, preventing keyboard errors.

Abstract: A radiation-sensing assembly adapted for sensing radiation emitted from a source of radiation which may be non-coal layers (shale and other materials) in a coal mine tunnel. The sensor assembly incudes a housing forming an enclosure for a radiation-sensing medium. A cover is provided on the top of the lower portion of the housing, and radiation passes through the cover to impinge on the sensing machine. The cover includes a collimator, which is built into the cover, to direct the radiation from the source to the sensing medium.

Abstract: A linear movable apparatus for imparting rotational movement to a turntable is provided. The turntable is secured to a rotatably mounted shaft having a ring gear thereon for meshed engagement with gear teeth provided on a piston rod which extends between a pair of pistons. Each piston is reciprocally carried in aligned cylinder housings mounted in a support structure. An adjustable mechanism is provided for retaining the piston rod in snug-fitting relation with the ring gear, and a bracket assembly is secured around the ring gear to support the adjustable mechanism against the ring gear.

Abstract: An enclosure is constructed of electromagnetic radiation shielding material for housing and supporting circuitry that emits electromagnetic interference. Symmetrical top and bottom covers are fabricated of a generally U-shaped configuration, with a downwardly extending tab on one side region of the upper cover and an upwardly extending tab on an opposite side region of the lower cover, these tabs for covering a butt joint between the upper and lower covers. Symmetrical front and rear covers are each constructed having inwardly extending sides also for covering the butt joints, with a lip on each of these side regions. Slots in these lips support circuit boards in the enclosure. Segmented lips on upper and lower sides of the front and rear covers contact upper and lower regions of the upper and lower covers. Constructed as such, there are no significant gaps in the enclosure to radiate electromagnetic radiation.

Abstract: A telescoping fluid actuator assembly including a housing having a plurality of concentrically disposed fluid actuators disposed therein. Each fluid actuator includes a cylindrical housing enclosing a piston and piston rod. Fluid passage means is provided for alternately directing fluid pressure to the front and back piston faces of each piston to effect forward and rearward movement of the pistons and the associated piston rod. The innermost concentric fluid actuator has a piston rod extending from the housing for engaging a workpiece for movement thereof. All of the concentrically mounted fluid actuators, except the innermost fluid actuator, is provided with a hollow piston rod which forms the cylinder housing for adjacent concentric fluid actuators.

Abstract: A regeneration circuit (16) is disclosed for regenerating noisy, received digital signals in a high impedance signal line (22). A buffer amplifier (30) is provided with a feedback resistor (36), with the feedback resistor and input to the buffer amplifier coupled to line (22) and to a pull-up resistor (34). The values of resistors (34 and 36) are selected such that when a normally "high" logic potential on line (22) is pulled "low" and then released, the buffer amplifier functions to source current to line (22) during the falling transition; and after the amplifier transitions "low," it sinks current from line (22). Thus, buffer amplifier (30) acts first as a pull-up device during the falling transition and then as a pull-down device during the rising transition. This restores the received logic signals to digital levels and reduces noise about the switching points in the rising and falling transitions.

Abstract: A linear braking mechanism for fluid actuators defined by a cylinder enclosing a cavity having a piston/piston rod assembly reciprocally mounted therein. The braking mechanism includes a spring biased body which is disposed for engaging and retarding the movement of the piston as it nears the end of its travel. A pressure equalizing metering port is provided in the body of the braking mechanism to equalize pressure on opposite sides of the spring biased body.

Abstract: A system for constructing concrete culverts is disclosed wherein reusable outer form and rebar supporting assemblies are set in place in an excavation and are used to form outer portions of the floor and outer walls of the culvert. Forming the outer walls of the culvert is facilitated by anchoring the lower regions of the form assemblies in the outer region of the floor as it is being poured by means of concrete anchors, which remain set in the concrete but are removable from the form assemblies. As a particular feature of this invention, the form assemblies are each provided with a protective wall spaced from the form assembly and adjacent walls of the excavation, forming a protective space where workers may work while being protected from collapse of walls of the excavation.

Abstract: Perforated plates (10) having very small holes (14) with a uniform diameter throughout the plate thickness are prepared by a "wire drawing" process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er.sub.3 Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans (20) containing erbium and nickel metals in a stacked array (53) with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er.sub.3 Ni.

Abstract: A high-speed public key cryptosystem is constructed for the encryption and decryption of digital data blocks, the creation and verification of digital signatures, and the creation of verifiable random number sequences. The encryption and decryption techniques employ a public key K constructed as the matrix product of a randomly generated nonsingular matrix M, and a rectangular template matrix T having row identifiers imbedded therein for selecting rows of a matrix M-1 that participate during decryption. Encrypting of a plaintext block, is achieved by converting the block to a nonlinear row selector code used to select rows of K. Columns of the selected rows are then added modulo-2 to produce a block if ciphertext.

Abstract: A data entry and error embedding system in which, first, a document is bitmapped and recorded in a first memory. Then, it is displayed, and portions of it to be replicated by data entry are underlayed by a window, into which window replicated data is entered in location and size such that it is juxtaposed just below that which is replicated, enhancing the accuracy of replication. Second, with this format in place, selected portions of the replicated data are altered by the insertion of character or word substitutions, thus the embedding of errors. Finally, a proofreader would endeavor to correct the error embedded data and a record of his or her changes recorded. In this manner, the skill level of the proofreader and accuracy of the data are computed.

Abstract: This invention is a constant current, noninverting, voltage amplifier powered by a single polarity of electrical power with respect to a ground potential. In a preferred embodiment, the amplifier consists essentially of a single transistor having a reference voltage applied to a base input thereof and an analog video signal coupled via a resistor to an emitter of the transistor. Also coupled to the emitter is a constant current source, with a collector of the transistor coupled to a monitor.

Abstract: A cooling apparatus is provided having a hollow, tubular base, with a tubular member extending upwardly therefrom. A fogging nozzle is mounted at an upper end of said tubular member and receives pressurized water and provides a fine fog of cooling water droplets. An adjustable valve admits water from a pressurized source to the base, stabilizing the base, and also admitting water to the nozzle.

Abstract: A communications link up to about 300 feet for use between a computer and display unit receives analog R, G, and B signals from the computer and applies them to discrete current amplifiers that modulate signal current applied to discrete conductors of a 300 foot cable. Impedance matching networks match the R, G, and B signals to the characteristic impedance to the cable. The R, G, and B signals are received near the monitor, and coupled to discrete emitter-follower transistors, which amplify current of the signals prior to inputting the signals to the monitor. The horizontal sync signal is applied to a conductor of the cable without impedance matching, allowing the conductor to attenuate the horizontal sync signal and reduce noise radiation.

Abstract: A clamp for tightening heating coils around a cylindrical object being heated has a split tubular housing with straps extending from each housing edge and forming loops pulled together by forces exerted from a pair of wedging elements with conical surfaces. The wedging elements have a cylindrical portion journalled in loops connected to one housing edge and a conical inner portion on which a strap connected to the other housing edge is mounted. Movement of the wedging elements axially with respect to one another changes the effective diameter of the conical portions engaging the strap. This causes the housing edges to be pulled together. Movement of the wedging elements with respect to one another is provided by securing one element to a mounting pin and providing a threaded bore through the other element, the element with the bore being restrained from rotation. When threads on the pin engage the threaded bore, the elements are pulled together.

Abstract: This invention pertains to circuitry for automatically coupling up to four keyboards to a single keyboard port of a computer. Switching is accomplished by sensing a clock pulse appearing on one of the keyboard clock pulse lines responsive to a keystroke appearing on one of the keyboards. The clock pulse is applied either to a set input or a reset input of a latch, depending from which of keyboard clock pulses lines the pulse originated. The set or reset condition of the latch evokes a selected voltage potential on the output of the latch, which biases "on" bi-directional switches, coupling one of the keyboards to the computer.