Abstract: Electronic display system in which a single memory is timeshared by a plurality of display units each including a cathode ray tube (CRT) television monitor capable of displaying a frame of characters in the form of one or more lines as well as a central processing unit and a number of input/output units. Character codes representing the characters in each character line being displayed are stored in blocks of storage locations in the memory, one character line per memory block. A plurality of frame display programs, one for each display element, are stored in separate blocks of storage locations. Each program specifies the order in which the character lines are to be displayed by its corresponding display element. A refresh control unit common to all of the display units includes a basic line counting means which is employed to sequentially execute the frame display programs in retrieving the character codes from the memory and loading them into unit line buffers for the various display units.

Abstract: A print hammer mechanism with a flexible interposer selectively moveable from a normal position into the path of a rotating impeller tooth which engages the interposer driving it and the associated hammer toward a print line to impact a print medium with a type die on a moving carrier. The interposer is flexible in the plane of motion of the hammer and the impeller tooth which allows slower and more controlled acceleration of the hammer and enhances the wear of the materials used to fabricate the hammer, interposer and impeller tooth. Uncontrolled oscillation of the flexible interposer and, hence, multiple strikes and multiple rebounds from the print hammer backstop are prevented by means of a mechanical linkage which captivates the interposer to the hammer for travel with the hammer but also allows the interposer to move from its normal position into the path of the impeller tooth and to return to its normal position.

Abstract: An improved method is disclosed for manufacturing a keyswitch assembly which includes a plurality of switches in a predefined arrangement on the face of an insulative circuit board and which also has a protective, insulative coating over the switches and board face. Each of the switches includes a pair of spaced contacts on the board face and a resilient, deformable, electrically conductive actuating element which can be selectively deformed to provide an electrical circuit between the two contacts. The method is performed with the aid of a planar template having a plurality of apertures positioned in a predefined arrangement corresponding to the arrangement of the switches on the circuit board. As an initial step, an insulative sheet, eventually forming the coating, is placed on a flat surface and the template is placed on top of the sheet so that the sheet is sandwiched between the template and the surface.

Abstract: A method of preparing an alignment disc pak in which first and second signals of different frequencies f1 and f2 are recorded in eccentric bands at a selected track on the disc such that the playback signal will consist of three components having frequencies f1, f2 and (f1-f2). One frame of the playback signal is first displayed with one beam of a multibeam oscilloscope on the display surface thereof such that the (f1-f2) signal component appears as a "cat's eye" pattern. The delay time base time marker is then employed to measure the time base of one of the cat's time marker is further employed to produce first and second narrow timing bands on either side of the intermediate crossover of the cat's eye pattern by erasing the recorded signals on the disc only in those radial sectors of the disc corresponding in position to two positons of the time marker on the scope as defined by the formula (Gc - Sp/2 .+-. 0.2.

Abstract: A keyswitch assembly including a circuit board having a plurality of circuits, each circuit terminating with a pair of first and second contacts, and a curved, resilient contact plate associated with each pair of contacts having at least a portion of its periphery in communication with one of the pair of contacts, the plate being selectively deflectable so that it communicates with the other contact to close the respective circuit. The contact plates are fixed in position by a retaining element comprising a film formed by a layer of thermoplastic material bonded to a flexible sheet of insulative material, the thermoplastic material being bonded to the resilient plates and circuit board thereby maintaining the former in correct position relative to the latter. The method of manufacturing the assembly includes precisely locating the plates over the pairs of contacts, placing the retaining element over the circuit board an applying pressure to the assembly at an elevated temperature for a predetermined time.

Abstract: A keyswitch assembly including a circuit board having a plurality of circuits, each circuit terminating with a pair of first and second contacts, and a curved, resilient contact plate associated with each pair of contacts having at least a portion of its periphery in communication with one of the pair of contacts, the plate being selectively deflectable so that it communicates with the other contact to close the respective circuit. The contact plates are fixed in position by a retaining element comprising a film formed by a layer of thermoplastic material bonded to a flexible sheet of insulative material, the thermoplastic material being bonded to the resilient plates and circuit board thereby maintaining the former in correct position relative to the latter. The method of manufacturing the assembly includes precisely locating the plates over the pairs of contacts, placing the retaining element over the circuit board and applying pressure to the assembly at an elevated temperature for a predetermined time.

Abstract: A ballistic print hammer assembly which includes a pivotally mounted print hammer driven by an electromagnetic actuator, characterized by low cost and ease of manufacture, high velocity and short dwell time. A rigid pivot upon which the hammer is mounted is simply secured to one side of a frame member. One end of the hammer is disposed in a slot of the armature of the electromagnetic actuator. The stator of the actuator is arranged to be inserted (by means of screw threads) from the other side of the frame member through an aperture so that the armature fits within the actuator stator cavity. An impression control spring is further disposed in a central cavity of the armature to continually produce a biasing force on the hammer which in the free-flight condition of the hammer is a decelerating force.

Abstract: Apparatus for feeding data processing record cards seriatim from the bottom of a stack to a data sensing station or the like including a pair of oscillating picker members for displacing a record card from the bottom of the stack, and a pair of sector rollers for intermittently gripping the displaced card and moving it at right angles to the direction of displacement to the nip of a set of feed rollers. Both the picker members and sector rollers are driven from a common source, the picker members being harmonically driven through a unique coupling device including a pair of flexural elements mounted at right angles to each other to give a universal action.

Abstract: A reversible drive apparatus for a flexible web, especially adapted to a reversible ribbon drive for a printing machine. A driving spur gear is arranged to be shifted between a pair of spur gears, each associated with a ribbon spool. The shifting is accomplished by mere reversal of direction of a drive motor which has a lead screw type shaft upon which the driving spur gear is mounted with mating screw threads. This allows the driving spur gear to travel laterally along the lead screw shaft between the pair of spur gears whenever the motor reverses direction.