Abstract: A Schmidt trigger voltage regulator having a latching circuit at its input to disable the regulator during an overload condition and automatically resets the latching circuit when the overload condition is removed thereby allowing the regulator to function in its normal voltage regulating mode.
Abstract: A switching regulator is series connected to an oscillator. A schmitt trigger responds to load voltage variations to control the on-off conditions of the switching regulator. When the switching regulator is on the oscillator is on to provide through transformer coupling an output to a capacitor connected across the load. When the voltage across the capacitor increases to a predetermined value the schmitt trigger turns the switching regulator off and thereby the oscillator too, the capacitor continuing to discharge into the load.
Abstract: A typewriter power roll having a hollow core is assembled with end bearings which are adapted to rotatably support the power roll on a stationary center shaft. Assembling the core and end bearings as a unit allows the periphery to be ground concentric with the bearing axes. After grinding, the power roll can be located in a typewriter and the center shaft inserted through side frame openings and the bearings and adjustably secured to the typewriter side frames at opposite ends by being wedged between a slotted surface of an adjusting plate adjustably secured to the side frames and an eccentric mounted on the adjusting plate.
Abstract: A temperature compensated regulator circuit makes use of the net positive temperature coefficient of voltage characteristic of a pair of back-to-back zener diodes to compensate for the negative voltage temperature coefficient of the base-to-emitter junction of a transistor.
Abstract: Machine for marking documents with visually readable printed information on one portion of the document, and with magnetically encoded information on another, magnetizable portion of the document. The magnetically encoded information is read to determine if it was recorded with an error. If it was, printing is prevented so that a document which has an error in the magnetically recorded information is presented as a blank, non-printed document. It is therefore readily apparent that the document is defective and should not and cannot be used.
December 20, 1971
Date of Patent:
May 18, 1976
Litton Business Systems, Inc.
Richard C. Graniere, Patrick J. Marshall
Abstract: A pair of electromagnets, each including pole faces separated by an air gap, cooperate with a permanent bar magnet, the ends of which extend into the electromagnet air gaps. Polarization of the electromagnets causes the bar magnet to shift into four possible positions thereby shifting a coupled print head to bring one of its four type bands into printing position.
Abstract: A print wheel of the type employed in business machines is formed by positioning a ring-shaped metal blank in a die and forcing fluid plastic under pressure against the ring thereby causing the metal to flow into the characters provided in the die and to assume their shape.
Abstract: A compact lightweight typewriter carriage having a rail supporting an escapement rack, tab rack and margin rack located relative to carriage supported control elements as to minimize twisting moments relative to its frame support incident to actuation and termination of carriage movement.
Abstract: A typewriter is provided with carriage control mechanisms such that more than one carriage control function can be initiated at one time. The arrangement of carriage function controls permit a dominant carriage movement to prevail, and less dominant carriage movement function controls will either give way or, in case of tabulation, give way and await completion of the dominant function while yet remaining in active position to arrest tabulating movement. No interlocking of carriage functions is necessary. More particularly, if a dominant carriage return is initiated, carriage return movement of the carriage will cause a backspace pawl, controlled by initiation of a backspace function, either immediately before or after carriage return movement begins, to move out of engagement from the escapement rack. If either a carriage or a backspace function is in progress, i.e., the carriage is moving to effect a carriage return or backspace, a tabulation function can still be initiated.