Abstract: In an electronic correcting typewriter, a character correction and replacement system is disclosed for facilitating the task of correcting typed character errors. The typewriter includes a printing and a correcting mechanism operated under electronic control and a correction buffer is associated with the electronic control for storing the last plurality of printed characters. To automatically erase any previously printed character which character has its code stored in the correction buffer and print a new replacement character, the typist locates the carrier opposite the unwanted character and actuates the character key of the desired replacement character. Under control of the electronics, the unwanted character code is recalled from the correction buffer, the correcting mechanism is operated to erase that character and the printing mechanism is operated to print the new character. Operator setting of an overstrike flag provides character overprint capability.

Abstract: In an electronic typewriter, an automatic word correcting system includes a keyboard word erase function key for selectively causing automatic erasure of a word or a series of words. Operation of the word correcting system is based on electronic sensing of "space" or non-print functions and successive recall of consecutively printed characters stored in a print line memory of a control circuit in the typewriter. To erase a previously typed word after other words have been typed, the operator aligns (backspaces) a carrier print point at any print line position occupied by the word. Then a single one touch (depress/release) actuation of the Word Erase Key operates an electronic word erase control that causes the carrier to automatically move to the right to find and then stop the carrier when the subsequent "space" function is electronically sensed in memory.

Abstract: A case shift and lock input mechanism comprising a pair of independently depressable shift keylevers and a depressable shift lock keylever are assembled in a keyboard for actuating a single shift control switch used to condition a printer for printing upper case characters when the switch is actuated. A pivotal bail member is interposed between the switch and each shift keylever for engageably actuating the switch in response to depression of either shift keylever. The shift lock keylever directly actuates the switch when it is depressed to a lock position. A latch device comprising a latch member pivotally mounted on the switch operates to releasably hold the shift lock keylever in the lock position to keep the switch closed for continual typing of upper case characters. The shift lock keylever is released from the lock position through the bail member by subsequent depression of either shift keylever. Each shift keylever actuates the switch independent of the shift lock keylever.

Abstract: A print element mounting apparatus for attaching and removing a print disc to and from a selector shaft in a printing machine. The apparatus comprises a finger-grip cap which is fixed on the print disc and a coupling device carried by the print disc. The coupling device includes a generally circular shaped unitary flex member made from yieldable half-sections which are continually urged towards one another by a spring wrapped about the flex member. Each half-section includes a pair of pressure surfaces which are curved in complementary relation to form a biased opening at the central portion of the flex member. The selector shaft is fabricated to include tapered surfaces that operate in conjunction with the pressure surfaces to afford snap-action operation during interchange of the print disc accomplished through a push or a pull force axially applied to the cap.

Abstract: A carriage locking device is used for locking a transversely movable carrier in a typewriter to safeguard against damage when the typewriter is not in typing use, especially during shipping transport. The device includes a pair of blades operable between a released position for enabling the carrier to travel sideways and a locked position for engageably holding the carrier fast in the typewriter. A lock control linkage is coupled to the blades for allowing the operator selective movement thereof to shift the blades between the two positions. The blades move into and out of a recess on the carrier which is only allowed to occur when the carrier is stopped at a predetermined location. A sensor lever includes a latching feature that operates in response to the carrier being away from the predetermined location to block movement of the lock control linkage for maintaining the blades in the released position.

Abstract: A ribbon cartridge handling apparatus has a pair of pivotal couplings for three position handling of a ribbon cartridge in a typewriter. The apparatus includes a cartridge receiving receptacle pivotally supported on a first pivot coupling on a rocker. A second pivot coupling on a frame support structure in the typewriter pivotally supports the rocker. A first operative position of the apparatus locates the receptacle in an open position for allowing insertion of the ribbon cartridge into the typewriter. A second operative position of the apparatus locates the receptacle together with the ribbon cartridge in a non-printing position located near a print station in the typewriter. The receptacle is operatively pivoted about the first pivot coupling between the first and second operative positions. A third operative position of the apparatus locates the rocker together with the receptacle carrying the ribbon cartridge in a print position at the print station in the typewriter.

Abstract: An improved acoustic transport member for use in a keyboard having key operated strikers individually actuatable for inducing acoustic energy in the form of sound waves which propagate through the member from selected inducing positions therealong. A first portion of the member is fabricated in the form of a series of tabs to provide discrete impact positions for generating sound waves in response to impact actuation of related strikers. A second portion integrally connected with the first portion links all of the tabs and functions as a sound corridor for receiving and transporting all sound waves generated as a result of the selected striker impacting its related tab. An aperture is provided through the tabs. A peripheral rim of the aperture provides sound reflecting boundaries that define sound passages on the tabs for directing the sound waves in different directions in communicating the sound waves from the tabs into the corridor.

Abstract: An acoustic transport member for use in a keyboard having key operated strikers individually actuatable for inducing acoustic energy in the form of sound waves which propagate through the member from selected inducing positions therealong. A first portion of the member is fabricated to provide discrete impact positions for generating sound waves in response to impact actuation of related strikers. A second portion integrally connected with the first portion links all impact positions for receiving and transporting all sound waves generated by the first portion. A step joins the first with the second portions to allow communication of the sound waves from the first portion into the second portion yet thereafter provides unidirectional acoustic separation therebetween which effectively minimizes wave dispersion by substantially isolating the propagating sound waves in the second portion from coming into contact with successive impact positions of the first portion.