Abstract: A jump return stack is provided in a data processor having a plurality of control registers including a fetch control register and an execution control register. The jump return stack comprises a memory stack, an address register, and a counter-register interposed between the memory stack and the control registers of the data processor. The counter-register is always made to store the latest entry into the memory stack, that is the top of the stack, such that the latest entry into the stack is immediately available to the control registers of the data processor thereby eliminating a memory access to the stack.

Abstract: This invention relates to an error detection circuit for detecting errors in a recovered clock signal from a self-clocking digital data signal. A first flip-flop is alternately set and reset by the recovered clock signal and by a clock source of supposedly equal frequency, respectively. The output of the first flip-flop is sensed by a second flip-flop at the end of a predetermined time period, as determined by the clock source, for determining that a transition in the recovered clock source occurred within the predetermined time period. If no transition occurred within the predetermined time period, the second flip-flop outputs an error signal.

Abstract: A multiwired print head having an elongated conical center member with wire guiding sections formed thereon and with a plurality of recessed portions for minimizing the surface contact area between the print wire and the elongated member. In addition, the elongated member mounted within a frame having actuators operating therewith for imparting axial motion to the print wires and having wire bridge supports for supporting the elongated conical member to the frame at positions corresponding to the raised portions of the conical member which bridge members act to retain the print wires in their recessed notches.

Abstract: A solar radiation absorbing structure including a plate comprising a plurality of co-planar fluid passageways joined side by side and having at least one radiation transmissive cover extending over the passageways. The opposite longitudinal edges of the plate parallel to the passageways and the corresponding longitudinal edges of the cover are interlocked with longitudinal rails to support the passageway plate and cover spaced from the roof structure. Only one part of each rail and plate and cover is locked in place on the roof; the remainder is free to move in response to thermal expansion and contraction. Manifolds at each end of the plate connect to the passageways to transmit liquid to and from the passageways. At each end of the cover a member, which may be hinged, forms, with the manifolds, a substantially airtight enclosure in cold weather.

Abstract: A support structure is provided for a sewing machine needle. The structure includes a simplified needle bar 14 having a solid end 34 with a transverse, threaded hole 36. A die cast needle clamp 11 is precision-formed with a hollow cylinder 13 that fits over the end of the bar and is attached by a screw 16. A needle channel 19 is cast in the clamp to hold the shank 22 of a needle with the flat surface of the shank against a flat surface 21 of the channel and the round part of the shank captured between another flat surface 32 and the conical end of a screw 23. The cross section of the channel 19 is large enough to receive standard needles but not so large as to receive the shank of the smallest standard needle improperly oriented.

Abstract: An annular disc is forced onto the central sleeve of the sewing machine bobbin case and held in place by the tight interference fit. A set screw within the limited area of the front wall, thick enough to hold the entire length of the screw, can be adjusted from outside the bobbin case to set the braking pressure of the disc against a bobbin flange to prevent excessive rotation of the bobbin and spillage of its thread.

Abstract: A sewing machine having a presser bar operated by a lever having a movable fulcrum to vary the mechanical advantage of the lever and thereby vary the effective pressure on the presser bar.

Abstract: A molded flying disc with most of the weight concentrated in an outer annular ring. The central opening in the ring is covered by a thin sheet of material, such as plastic or cloth, stronger than a sheet of the molded material of the same thickness and diameter. The perimeter of the sheet is attached to the ring.

Abstract: A timer, especially for cardiopulmonary resuscitation, to generate multiple series of pulsating signals to be used by one or more rescuers to time different, but related, operations in reviving a victim whose heart and breathing have just stopped. The pulses of each series are repetitive at different rates, and the first pulse of each series starts after a certain number of pulses of a preceding series has been generated.

Abstract: A work feeding mechanism for sewing machines including a feed dog with two pair of mutually orthogonal serrated teeth to drive a fabric past a stitch forming area in directions defined by mutually orthogonal axes. The feed dog is pivotally fastened to one extremity of a feed bar whose opposite extremity is suspended by gimbals from a slidable member carried in the bed. Means are disclosed to selectively impart oscillations of a varying amplitude and direction to the slidable member in timed synchronization to the motion imparted to the feed dog, to drive the feed dog in lateral and longitudinal directions of fabric feeding motion which extend along the length of the sewing machine bed and normal to the length of the bed. Fabric feeding information for the work feeding mechanism may be stored in an electronic memory to permit the production of ornamental stitch patterns.

Abstract: An extruded solar panel formed as a unit and including a plurality of co-planar fluid passageways joined side by side and having at least one radiation transmissive cover extending over the passageways. The edges of the cover are joined to the edges of the group of passageways to form a dead-air space over the passageways. The opposite longitudinal edges of the cover and passageway structure have flanges that can be interlocked for ease of assembly, and one or more ribs are provided to support the passageways from the roof structure.

Abstract: A ski structure having a trapezoidal, foamed core wrapped with fiber-reinforced plastic with its wider base facing downward. The plastic sections covering the base and top of the trapezoidal core are rigidly joined to juxtaposed layers of fiber-reinforced plastic, which, in turn are combined with other layers of suitable material into a generally boxlike structure shaped like a ski. The spaces within the boxlike structure on each side of the trapezoid are also filled with foamed material.

Abstract: A system including a data modem having transmitter and receiver sections. The modem transmitter includes a multi-level data encoding system, a stable carrier generator and a selected transmission frequency, and a double sideband suppressed carrier modulator to modulate the multi-level signals on the carrier. All filtering to shape the signals in the transmitter section is done prior to modulation and, in the receiver section, after demodulation. Signals from several modem transmitters, each occupying its own assigned band, are multiplexed with two pilot carriers spaced by a predetermined frequency difference. The modem receiver includes a circuit to separate one of the carriers from the received band and mix that carrier with signals in a limited part of the band to shift the frequency of signals in the limited part of the band to an intermediate frequency (IF) band. A desired signal can be selected by frequency-shifting the IF signals so that the carrier frequency of the desired signal is at zero.

Abstract: A vacuum pump controlled by a timer periodically evacuates a metering chamber to draw liquid samples into the chamber from a source. A switch is actuated when the liquid level reaches a predetermined point and causes the motor to stop. An electrically controlled valve is connected to the metering chamber above the level of the intake nozzle of the pump and is closed when the pump is operating and open when the pump is stopped, thereby allowing air to enter the upper part of the chamber to relieve the vacuum and allow the metered sample to flow out through an outlet tube to a sample receptacle. The outlet tube is controlled by a vacuum operated pinch valve to be closed during sample intake so that the pump will not have to evacuate the sample container before starting to draw liquid into the metering chamber.

Abstract: An array of bent wire connectors to grip the edge of a printed circuit board is held in spaced, opposed grooves on facing side walls of a holder so that the whole array can be affixed to a mother board as a unit by soldering the free ends of the connectors in place. The grooves can be preformed to hold the connectors in the array, or they can be formed in situ by heating a jig with the connectors assembled in a similar array of holes in the surface of the jig and then pressing a thermoplastic holder onto the connectors. The heated connectors soften the contiguous portions of the holder, and after the latter is in place, the assembly is allowed to cool so that the thermoplastic material can reharden in gripping relation to the connectors. A bar can separate gripping portions of the connectors to align them and give them a pre-set position to receive the edge of the printed circuit board easily.

Abstract: Frequency response of a signal path over which frequency-spaced signals are transmitted is analyzed by sweeping relatively narrow pass band tunable receiving means across the frequency band expected to be received at the location to be analyzed. Incoming signal to which the tunable receiving means is tuned at any instant is used to control the frequency of a voltage controlled oscillator. The frequency of oscillations produced by the oscillator has a known relationship to the amplitude of the instantaneously received signals, and these oscillations are transmitted to a frequency-to-amplitude converter at a measuring location. The converter produces an output signal that has an amplitude which is a function of the frequency of oscillations applied to it. A spectrum indicator at the measuring location is connected to the converter to produce a visual display of the amplitude of signals received at the location at which the characteristics of the transmission path are being analyzed.

Abstract: A process for making bulky elastic texturized acetate yarn having good elasticity, good tensile strength and good durability of elasticity and tensile strength in washing and dry cleaning which comprises applying to acetate yarn a curable synthetic resin, applying to said acetate yarn a twist wet heat setting agent, bulking and texturizing said acetate yarn by imparting a false twist thereto, heating said yarn to twist wet heat set said false twist, dissolve twisting said yarn, drying said acetate yarn and heat treating said dried acetate yarn to cure said curable synthetic resin therein, and bulky elastic texturized acetate yarn so made.