Abstract: The impact velocity with which a single element printer prints is determined by the velocity with which the printing element is propelled toward the record sheet. The mechanism disclosed herein is capable of adjusting the velocity with which a print element is projected toward the page such that the impact velocity and, thus the impact forces which are related to the velocity, are controlled and varied to provide a minimum of compromise with respect to printing forces and, thus, print quality. The control of the velocity with which the print element is propelled against the record sheet is accomplished by a cam which rotates with the print element during character selection and has thereon a plurality of rises corresponding to a displacement of a cam follower engaged with a print cam. The print cam is formed to present, in a plurality of different planes perpendicular to its axis, a like plurality of cam profiles and rises.

Abstract: A typewriter correction tape cartridge for holding and feeding correction tape for a correcting typewriter is improved by the addition of a beam spring cantilever supported such that one end of the beam spring wipes the correction tape onto the takeup spool. This will act to eliminate bubbles, wrinkles and crimps in the tape as it is placed in a new convolution on the spool and will thus reduce the outside diameter of the ultimate disc of used tape. The advantage of this spring is that a reduced size cartridge may be used while utilizing the entire volume of tape supplied on the supply side of the cartridge and, secondly, a more reliable takeup is accomplished due to the elimination of irregularities in the takeup disc.

Abstract: A support for an idler gear is pivotally mounted about the driving gear axis in a gear driven platen drive for a typewriter. A constraining member mounted with the interchangeable platen engages and constrains the support in a position to insure engagement of the idler with the platen gear and may be sized or shaped to insure proper positioning of the support and idler for a number of different platen gears of varying diameters, allowing platens and platen gears to be readily changed to vary the line feed increment as desired by the operator.

Abstract: A powered gear driven paper insert and line feed mechanism capable of rotating a platen through one half line spacing increments and which is both power operated and disconnectable for manual operation is disclosed. The platen of the typewriter or printer may be manually rotated using platen or may be electronically rotated by energizing the control magnet, thus engaging the clutch assembly to connect the drive motor to the platen. The clutching assembly is such that two separate clutches are operable to disconnect the platen and gear train from the overall clutch apparatus and also to disconnect the drive motor belt and other related hardware which is driven by the drive motor and belt.

Abstract: In a typewriter ribbon cartridge, it is necessary to maintain tension on the span of ribbon extending outside the cartridge to prevent tangling and to insure high print quality during machine operation. One technique for insuring that adequate tension is maintained is disclosed herein as an anti-backup back check device. Connected to the takeup spool of the ribbon cartridge is a disc member supporting thereon a pair of thin flexible resilient arms with outwardly oriented pointed ends. These ends formed in the shape of points engage ratchet teeth formed around the interior surface of a cylinder. The cylinder is formed as a part of the ribbon cartridge and, thus, is permanently positioned and fixed with respect to it. As the takeup spool disc and arms are rotated by the ribbon feed mechanism, the arms will flex and permit a rotation of the disc and takeup spool with a minimal drag force.

Abstract: In ribbon cartridges which are utilized in cooperation with a spacially fixed driving member engageable with a takeup spool at its periphery to feed the ribbon, it is necessary for the takeup spool to translate away from the spacially fixed driving member as the spool accumulates ribbon and the consumed ribbon forms disks of increasing diameter. A frangible portion of the cartridge may be utilized in conjunction with its transverse engagement with an extending axle coaxial with the takeup spool to resist the movement of the takeup spool into the chamber of the cartridge except as is forced by the increasing diameter of the ribbon disk formed on the takeup spool. The frangible section of the cartridge may be formed either during molding operation or as an additional member being added during assembly and will break or tear as the axle of the takeup spool is forced away from the end of the cartridge by the increasing diameter of the ribbon disk and the force of a driving member engaging the ribbon periphery.

Abstract: An improvement to the shuttle selection control system disclosed in U.S. Pat. No. 4,094,397 is described where a biasing spring is urgingly engaged with the rack of a rack and pinion arrangement used to rotate the type element, and thereby place a spring load on the system such that the force between the slider blocks of the selection system and the stop member engaged by the slider block will be reliably increased, while at the same time, preventing an increase in the drive requirements of the drive motor for the system. This spring biasing has a secondary benefit in that it tends to uniformly cause consolidation of all tolerances and relative movement in the system due to wear and thus stabilize the system for improved detenting of the typehead.

Abstract: A hollow tubular rubber or rubberlike deformable member is supported by a plurality of character keylevers in a typewriter keyboard and constrained against movement within the typewriter by supporting surfaces on the keylevers such that the tube engages the keylever pawls carried by the keylevers. As the keyboard of the typewriter operates, an interposer will force the keylever pawl rearward to provide complete restoration of the selection interposer. If the pawl did not rotate and the keylever is still in its depressed position upon the completion of the keyboard cycle, the selection logic would not be cleared and any following keylever input would result in a malselection. Also, interposer loading would prevent keylever restoration. The force of the interposer against the front edge of the keylever pawl will force the keylever pawl to pivot about its pivot stud and to locally compress the tube spring, formed out of a resilient pliable rubber-like material.

Abstract: A single print element of a typewriter has the characters thereon impact a record sheet at one of two velocities depending on the area of coverage of the character. Each character on the print element is selected for printing by movement of one of a plurality of interposers with each interposer selecting two characters. One of the two characters is selected by movement of the interposer when a pair of operatively connected shift levers is not depressed while the other of the characters is selected by the same interposer when the shift levers are depressed. A vane, which extends between the shift levers and is pivotally connected thereto, is disposed in the path of movement of all of the interposers. The vane has an opening for each interposer when the print element is to impact the record sheet at the higher velocity so that the vane is not engaged by the interposer during movement of the interposer.

Abstract: A variable cam profile selection system is disclosed having cams controlling both the tilt and the rotate motion of the single element typewriter. The tilt cam and rotate cam are mounted so that they may be moved with respect to their support to vary the cam rise. The rise of the cam is controlled by interposers under the influence of the keyboard to select or define the amount of movement of the cam member, thereby defining the cam rise. The single cam member for each movement may be positioned in any one of a plurality of positions and, by so doing, correspondingly effect the movement of the cam follower as the cam is rotated about an axis.

Abstract: A mechanism which will function to allow the escapement of the carriage of a typewriter in one of two predetermined escapement pitches and be capable of backspace operation from a single backspace input for both pitches regardless of which escapement pitch is selected. Escapement ratchets for the two selected pitches are combined, together with a backspace ratchet. Each of the escapement ratchets are engageable by an escapement pawl and the engagement of a pawl with a particular ratchet will determine the pitch within which the escapement system will function. A backspace ratchet is combined with the escapement ratchets and fixedly attached thereto to provide the backspace drive. The backspace ratchet is selectably engageable by the backspace pawl for causing rotation in the opposite direction of that normally utilized for escapement.

Abstract: A device is disclosed for shifting a bifurcated rack from one position to a second position, thereby engaging alternate sides of a bifurcated rack member with a pinion in a spacially fixed position. The rack shift mechanism is controlled by a direct link to the keyboard of the typewriter which responds to movement of a shift key lever. The mechanism performs a force multiplication and, at the same time, a displacement division function to reduce a relatively large key lever and link displacement to a relatively small rack displacement with a correspondingly higher force factor. The force multiplication linkage translates the rack of the rack/pinion pair to engage the alternate portion of the rack, thereby reversing the rotation of the pinion and allowing the selection from the opposite hemisphere of the type element in response to a selection output.

Abstract: Described herein is a feature and the electronics and logic necessary to implement a paragraph indent feature on an electronic typewriter which is improved and more advantageous than previous routines which accomplished similar results. Paragraph Indent is beneficial to the operator in that it automatically positions the printing carrier at an indented level for setting off typed material so that the left edge of the indented material does not extend to the normal left margin. The typewriter under electronic control stores in memory, upon an appropriate command, a temporary left margin to which the carrier will return when the typewriter is operating under the paragraph indent mode. The operator may enter the Paragraph Indent mode from the keyboard by keying an alternate function or code signal together with a tabulation or tab code signal.

Abstract: On electronic typewriters which have the ability to record into a small working memory those characters, functions and escapements which are keyed at the keyboard, it is many times advantageous to be able to place the carrier and the print point over a character which has been previously typed without using repeated backspaces. Disclosed herein is a feature for an electronic typewriter which permits the operator to easily align the print point with a character on the page by positioning a reference mark on the card holder or print carrier in relation to a previously printed character and then through keyboard control cause the carriage to shift its position such that the print point is then exactly aligned with the character printed.

Abstract: On electronic typewriters which have the ability to record into a small working memory the escapement of the characters which are keyed at the keyboard, it is many times advantageous to be able to reposition the carrier at the rightmost end of the typed material automatically. This is particularly advantageous when it has been necessary to back the carrier up along the printed line for purposes of erasing, correcting or inserting material into that line. Disclosed herein is an electronic typewriter which is controlled by the electronic logic such that the depression of a selected control key will result in the carrier moving from a position within the typed text on a particular line to the right most position the carrier has occupied within that line during earlier typing.

Abstract: An electronic typewriter which has the capability of erasing characters automatically and which has the further improved capability of being able to back through unused space on the line, which results after a tabulation command, thereby allowing the repositioning of the type element over the characters typed prior to the tab command thereby allowing automatic erasure of those characters. The improvement of the typewriter as described permits the retrieving of characters from an electronic memory and the use of that memory to control the erase cycle even where the carrier position and the character to be erased are on opposite sides of space without printed characters due to a tab command. This is accomplished by the electronic control of the mechanical hardware and the ability to determine where the tab command was entered on the typing line and to prevent erasure cycles in the unprinted space until the carrier has returned to the point at which the tabulation command was entered.

Abstract: A ribbon exit control, for a random stuffing ribbon cartridge is disclosed which prevents the accidental jamming of the ribbon at the exit port of the storage chamber. The exit port is formed by two mating members whose surfaces are configured, when mated, to form a slot of curvelinear shape such as the form of an arc of a circle or an angled relatively flat lazy V shape. An alternate form is a slot punched in a one piece member to define the slot. The deformation of the slot from that of a straight line causes the ribbon to buckle as it is pulled from the storage chamber and to assume a cross-section other than that of a straight line. This acts to separate the ribbon strand being removed from the chamber, from any other adjacent folds of the ribbon. Since the ribbon strand and the adjacent folds are separated by the deforming of the ribbon it is more difficult for an adjacent fold to be pulled into the exit gate thereby causing a jam.

Abstract: A paper feed roll assembly is disclosed which is pivotally mounted on a central point with three degrees of freedom of movement. The feed rolls are engageable with the periphery of the platen. Additionally, the support for the paper feed rolls is deflectable about the central point by a feed roll release member to effect the withdrawal of the feed rolls from the periphery of the platen to enhance paper insertion and removal. The pivot point support provides for freedom of movement in the three necessary degrees of freedom to allow equilization of feed roll force against the platen and for alignment of the feed rolls with the periphery of the platen to insure proper paper feed. The feed roll truck frame, by virtue of its pivotal mounting, may be deflected downward to permit release or insertion of the paper. A deflection means or eccentric bar is disclosed for deflecting the truck member away from the periphery of the platen against the force of the pivot support acting toward the platen.