TYPEWRITER BACKSPACE AND RIBBON-FIELD CONTROL
United States Patent 3595362
A typewriter of the single-element ("golf-ball") printing element-type, with laterally fixed paper support and a movable carrier for the single-element printing element, including means disposed at a fixed location on or near the keyboard for conveniently adjusting the vertical throw of the ribbon vibrator on the carrier, regardless of carrier movement, to select the color or kind of printing impression. The control means is interconnected with a pair of carrier back-spacing keys to facilitate automatic ribbon-field changes when a two-field ribbon of the error-correcting type is employed.
US Patent References:
Typewriter input checking mechanism
Becker et al. - March 1963 - 3082854
Typewriter erasure mechanism
Fondiller - September 1966 - 3270852
Constant torque drive means for typewriter
Cralle - April 1967 - 3313389
Erasure tape mechanism for typewriters
Hobbs - August 1968 - 3397767
Typewriter input checking mechanism
Becker et al. - March 1963 - 3082854
Typewriter erasure mechanism
Fondiller - September 1966 - 3270852
Constant torque drive means for typewriter
Cralle - April 1967 - 3313389
Erasure tape mechanism for typewriters
Hobbs - August 1968 - 3397767
Application Number:
04/867992
Publication Date:
07/27/1971
Filing Date:
10/21/1969
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
400/229, 400/697.100, 400/240.100, 400/208
International Classes:
B41J29/36; B41J35/14; B41J29/26; B41J35/04; B41J33/56
Field of Search:
197/91,151,157,158,159
Primary Examiner:
Wright Jr., Ernest T.
Claims:
What I claim is
1. In a typewriter of the kind having a keyboard, a carrier translatable in the linewise direction across an impression sheet, a single-element character imprinting member mounted on said carrier, an impression ribbon vibrator mounted on said carrier, and a ribbon control on said carrier for adjusting the throw of said vibrator to select the ribbon field to be interposed between said imprinting member and the impression paper, the improvement which comprises:
2. A typewriter in accordance with claim 1, in which said manually operable means comprises at least one keylever forming part of said keyboard.
3. A typewriter in accordance with claim 1, in which said manually operable means comprises a pair of interrelated keylevers adapted to move said rod toward the respective opposite limits of its range of positions.
4. A typewriter in accordance with claim 3 including backspacing means for said carrier, and in which said keylevers are both connected to operate said backspacing means.
1. In a typewriter of the kind having a keyboard, a carrier translatable in the linewise direction across an impression sheet, a single-element character imprinting member mounted on said carrier, an impression ribbon vibrator mounted on said carrier, and a ribbon control on said carrier for adjusting the throw of said vibrator to select the ribbon field to be interposed between said imprinting member and the impression paper, the improvement which comprises:
2. A typewriter in accordance with claim 1, in which said manually operable means comprises at least one keylever forming part of said keyboard.
3. A typewriter in accordance with claim 1, in which said manually operable means comprises a pair of interrelated keylevers adapted to move said rod toward the respective opposite limits of its range of positions.
4. A typewriter in accordance with claim 3 including backspacing means for said carrier, and in which said keylevers are both connected to operate said backspacing means.
Description:
BACKGROUND OF THE INVENTION
Typewriters of the single-element printing font-type, particularly those in which the printing element is a truncated spherical element, have become increasingly popular for office and general use. In a typical form, sold commercially by the International Business Machines Corporation under the trademark "Selectric," the paper carrier and platen roller assembly is relatively fixed with reference to lateral motion, and the printing font element is carried by a reciprocable carriage that moves stepwise across the paper held by the platen, to effect the successive character imprints. In this kind of machine, the usual ribbon vibrator, which carries the ribbon into imprint position as each character key is operated, and drops the ribbon thereafter to provide good visibility of the imprints, is also carried by the font element carrier. Thus, the selecting means that determines the vertical throw of the vibrator, and hence selects the particular ribbon field in use, is also on the moving font carrier. For many purposes, it would be vastly more convenient for the operator of the machine to be able to select the ribbon field from a keyboard-located control, and this is especially true in machines intended for use with ribbons of the self-correcting type, in which one ribbon field is inked to make ordinary character imprints, and another ribbon field is provided with an imprint-obliterating material to facilitate correction of printing errors.
Two-field self-correcting ribbons are disclosed in my prior U.S. Pat. Nos. 3,114,447 of Dec., 1963, and 3,141,539 of July, 1964, and others. Typewriter arrangements by which the proper ribbon field (printing, or correcting) is selected automatically when one or another of two backspace keys is operated, are disclosed in my prior U.S. Pat. Nos. 3,149,711 of Sept., 1964, 3,154,183 of Oct., 1964, and 3,204,745 of Sept., 1965, and others.
The typewriters with backspace-key-control of the ribbon field, as described in the patents mentioned above, are generally of the type in which there is a laterally-movable paper carriage cooperating with a relatively fixed assembly of plural-type bars. In the single-element printing element-type, as exemplified for example in U.S. Pat. No. 2,879,876, Palmer et al., of March, 1959, the ribbon feed and control elements are mounted upon the movable font-element carrier, and access to that carrier is necessary for the operator to select which ribbon field is to be used. A detailed disclosure of one form of ribbon-vibrator control for such typewriters is contained in U.S. Pat. No. 2,919,008, Whippo, of Dec., 1959. As is obvious, the fact that access must be had to the moving type-font element carrier, to adjust the throw of the ribbon vibrator, makes it impractical to coordinate the ribbon-field selector with a keyboard control so that control can be exercised throughout the horizontal motion of the font carrier; likewise, it is difficult to arrange matters so that different backspace keys can be operated to shift a self-correcting ribbon into and out of use positions.
SUMMARY OF THE INVENTION
The present invention provides a typewriter of the single-element printer-type, whose printing element is on a horizontally moving carrier, with means whereby the ribbon-field shifting control can be exercised from the keyboard of the machine, and hence can readily be coordinated with an automatic field-shifting control related to the operation of backspace keys employed in a print correction operation. In general, the invention adds to the carrier-mounted ribbon shift control linkage an operating member which straddles or embraces a longitudinal control rod, extending parallel to the travel path of the font element carrier, so that the freedom of movement of the carrier is unimpaired. The control rod is mounted for swinging motion, through a limited angle, toward and away from the carrier, under control of a keyboard-mounted (or otherwise conveniently located) instrumentality. In particular, and especially for use with self-correcting ribbons as described above, the keyboard mounted instrumentality may be a pair of backspace keys, whose selective operation therefore serves automatically to accomplish the necessary ribbon shift to bring the printing, or the correcting, fields of the ribbon, selectively into play.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 of the drawing is a schematic perspective view of a typewriter of the single-element printing member kind, showing the invention applied thereto.
FIG. 2 is a fragmentary sectional view, taken on line 2-2 of FIG. 1, and to a larger scale.
FIG. 3 is a schematic perspective view of the ribbon vibrator of the same typewriter, and its controls, showing keyboard control of the ribbon-field selection, coordinated with a pair of backspace keys.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1 of the drawing, the typewriter is shown with its outer casing parts removed, for clarity of illustration. The frame 10 of the machine supports a rotatable paper platen roller 12 having control knobs 14, and the usual paper bail 16. Impression paper is fed by rotation of the platen roller 12 as usual, but the platen 12 does not move laterally of the machine. The single-element printing member is shown as the usual truncated sphere 18, mounted on a traveling carriage or carrier 20 to swing towards the impression paper for printing through a ribbon 22 wound on reels in a removable ribbon cartridge 24, and guided near the printing point through the usual guides and vertical ribbon-vibrator 26. All of these printing parts travel across the impression paper as the carriage 20 steps by letter-space increments under control of the usual keys 28. Besides the character keys 28, the keyboard is provided with a pair of backspace keys 30 and 32, a space bar 34, shift key 36, carrier-return key 38, and other usual typewriter controls.
The ribbon cartridge 24 contains a ribbon 22 such as a black, or black and red, or black and correction, or other combination of sections as well known in the typewriter business. Either an upper or a lower portion of the ribbon 22 may be caused to be thrown up into position between the font element 18 and the impression paper, the selection heretofore being made by the manual adjustment of a control lever or knob which is positioned at the front of the traveling carrier 20. For use in the present invention, however, this ribbon-field selecting control is terminated not in a manual lever or knob, but in a split or bifurcated piece 40 adapted to straddle, and to slide along, a longitudinal control rod 42 mounted at either end upon swinging cranklike levers 44 and 46. The latter are pivoted upon suitable fixed supports 48 and 50 secured to the fixed frame 10 of the machine, and at the right-hand end, for example, the crank lever 46 is secured on a stub shaft 52 to which is fastened a control plate 54 by which the position of the control rod 42 can be altered, towards or away from the ribbon cartridge 24. The plate 54, therefore, serves to position the bifurcated piece 40 and hence to select the vertical throw of the ribbon vibrator 26.
At the far end of control rod 42, the crank lever 44 is pivoted on the support 48 as by a stub shaft 56 secured to the rod 42, and carrying a detent lever 58 having a pin or knob 60 that cooperates with a detent spring 62 fastened to the typewriter frame 10 and shaped to establish limits to the position which control rod 42 can take with reference to the path of travel of carrier 20. These positions correspond to adjustment of the ribbon vibrator 26 so that its vertical throw will bring either a higher or a lower segment of the dual ribbon 22 into use for each character printing operation.
FIG. 2 of the drawing better illustrates the construction of the traveling carrier 20 and parts associated therewith, and their relation to the paper platen 12, as well as the manner of operation of the vibrator control linkage. The carrier frame is indicated at 64, guided for motion parallel to the writing line on the impression paper by parallel shafts 66 and 68, the latter of which has a splined connection with a cam 70 whose rise provides the upward throw of the ribbon vibrator 26 in synchronism with the imprinting motion of the single-element printing font member 18. Specifically, the vibrator 26 moves from the position shown in full lines to the upper position (in dotted lines) by virtue of the parallel-linkage arms 72, 74 pivoted at their left ends on a depending lug 76 beneath the table 78 supporting the ribbon cartridge 24 upon the traveling carrier frame 64. Conventional ribbon-feed mechanism 80 surmounts the table 78.
The vertical "throw" of the ribbon vibrator 26 results from the upward swinging movement of a plate 82 pivoted on the carrier frame at 84 and held in contact with cam 70 by a spring 86. The motion of plate 82 is transmitted to one of the parallel-motion arms 72, as indicated by dashed-line positions of these parts in FIG. 2, through the interposition of a control rod 88 whose right end passes beneath the arm 72 and into a slot 90 of the plate 82. The position of the control rod 88 along the slot 90 governs the rise of the vibrator 26, because that position determines the distance that the point of application of the lifting force is spaced from the pivot axis of arm 72. The position of control rod 88 is, in typewriters of this kind as heretofore made, controlled by a manually operable knob or the like mounted on a mechanism table 92 secured to the traveling carrier 20. In the present construction, the control rod 88 is connected by its clevis 94 to a crank 96 pivoted at 98 to the table 92 or to a lug 100 depending from said table 92, or to any other fixed part of the carrier frame 64.
The upper end of crank 96 terminates in a bifurcated formation 40 here represented as a pair of depending fingers 102, 104 which can be bent, or otherwise adjusted with reference to the body of the crank 96, and which straddle or encompass the longitudinal control rod 42 already described as extending along and parallel to the path of travel of the carrier 20. The way in which a limited motion of control rod 42, to the right in FIG. 2, will shift the right end of control rod 88 to the right in slot 90, to produce a smaller vertical lift of the ribbon vibrator 26, will be obvious. It is also obvious that this control arrangement will operate for all positions of the carrier 20 along or parallel to the writing line of the machine, without interference with the usual spacing and backspacing (or carrier-return) movements.
FIG. 3 of the drawing shows more clearly the essential parts as described above, and also a convenient way in which control of the throw or lift of the ribbon vibrator 26 is coordinated with the operation of one or another of the two backspace keys 30, 32 of the typewriter. The parts of the parallel-arm linkage 72, 74 and 76 described above are duplicated at the opposite side of the ribbon vibrator 26 as indicated by the corresponding numerals with prime marks appended. The other parts described are identified by the reference numerals mentioned above, as are the two backspace keys 30 and 32. The keylevers of these backspace keys 30, 32 independently control, through linkages of conventional construction at 106 and 108, the carrier backspacing mechanism 110, which may be as described in the Palmer patent mentioned above. In addition, the respective backspacing keylevers are linked, as by bent control wires 112 and 114, to portions of the control plate 54 that lie on opposite sides of the fulcrum defined by the stub shaft 52 of the crank arm 46.
For adjustment purposes, the upper ends of the control wires 112 and 114 are shown as threaded, and they pass loosely through holes in the opposite ends of control plate 54 to provide a lost-motion connection thereto. In the position shown in FIG. 3, backspace key 32 was last depressed, tipping plate 54 clockwise, and shifting control rod 42 to its left-hand position, to move control rod 88 into the full-line position marked "H" on the ribbon vibrator arm 72, so that the lower section of the ribbon 22 will be used. When the other backspace key 30 is depressed, control plate 54 will be rocked counterclockwise, moving rod 42 to the right, and adjusting the control rod 88 to the "L" position, providing for use of the upper section of the ribbon 22. In this way, the selective use of a printing ribbon segment, or a correcting ribbon segment, is coordinated with the use of a selective one of the two backspace keys 30, 32 as described in connection with other kinds of typewriters in my patents mentioned above.
As a convenience in adjusting the amount of "throw" of control rod 42 produced by the operation of the backspace keys 30, 32, locknuts 116 and 118 are shown as engaging the threaded upper ends of the control wires 112 and 114. It will be understood, by those skilled in the art, that in mass production of typewriters including this invention, other and less cumbersome means may be substituted for the making of such adjustments.
Typewriters of the single-element printing font-type, particularly those in which the printing element is a truncated spherical element, have become increasingly popular for office and general use. In a typical form, sold commercially by the International Business Machines Corporation under the trademark "Selectric," the paper carrier and platen roller assembly is relatively fixed with reference to lateral motion, and the printing font element is carried by a reciprocable carriage that moves stepwise across the paper held by the platen, to effect the successive character imprints. In this kind of machine, the usual ribbon vibrator, which carries the ribbon into imprint position as each character key is operated, and drops the ribbon thereafter to provide good visibility of the imprints, is also carried by the font element carrier. Thus, the selecting means that determines the vertical throw of the vibrator, and hence selects the particular ribbon field in use, is also on the moving font carrier. For many purposes, it would be vastly more convenient for the operator of the machine to be able to select the ribbon field from a keyboard-located control, and this is especially true in machines intended for use with ribbons of the self-correcting type, in which one ribbon field is inked to make ordinary character imprints, and another ribbon field is provided with an imprint-obliterating material to facilitate correction of printing errors.
Two-field self-correcting ribbons are disclosed in my prior U.S. Pat. Nos. 3,114,447 of Dec., 1963, and 3,141,539 of July, 1964, and others. Typewriter arrangements by which the proper ribbon field (printing, or correcting) is selected automatically when one or another of two backspace keys is operated, are disclosed in my prior U.S. Pat. Nos. 3,149,711 of Sept., 1964, 3,154,183 of Oct., 1964, and 3,204,745 of Sept., 1965, and others.
The typewriters with backspace-key-control of the ribbon field, as described in the patents mentioned above, are generally of the type in which there is a laterally-movable paper carriage cooperating with a relatively fixed assembly of plural-type bars. In the single-element printing element-type, as exemplified for example in U.S. Pat. No. 2,879,876, Palmer et al., of March, 1959, the ribbon feed and control elements are mounted upon the movable font-element carrier, and access to that carrier is necessary for the operator to select which ribbon field is to be used. A detailed disclosure of one form of ribbon-vibrator control for such typewriters is contained in U.S. Pat. No. 2,919,008, Whippo, of Dec., 1959. As is obvious, the fact that access must be had to the moving type-font element carrier, to adjust the throw of the ribbon vibrator, makes it impractical to coordinate the ribbon-field selector with a keyboard control so that control can be exercised throughout the horizontal motion of the font carrier; likewise, it is difficult to arrange matters so that different backspace keys can be operated to shift a self-correcting ribbon into and out of use positions.
SUMMARY OF THE INVENTION
The present invention provides a typewriter of the single-element printer-type, whose printing element is on a horizontally moving carrier, with means whereby the ribbon-field shifting control can be exercised from the keyboard of the machine, and hence can readily be coordinated with an automatic field-shifting control related to the operation of backspace keys employed in a print correction operation. In general, the invention adds to the carrier-mounted ribbon shift control linkage an operating member which straddles or embraces a longitudinal control rod, extending parallel to the travel path of the font element carrier, so that the freedom of movement of the carrier is unimpaired. The control rod is mounted for swinging motion, through a limited angle, toward and away from the carrier, under control of a keyboard-mounted (or otherwise conveniently located) instrumentality. In particular, and especially for use with self-correcting ribbons as described above, the keyboard mounted instrumentality may be a pair of backspace keys, whose selective operation therefore serves automatically to accomplish the necessary ribbon shift to bring the printing, or the correcting, fields of the ribbon, selectively into play.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 of the drawing is a schematic perspective view of a typewriter of the single-element printing member kind, showing the invention applied thereto.
FIG. 2 is a fragmentary sectional view, taken on line 2-2 of FIG. 1, and to a larger scale.
FIG. 3 is a schematic perspective view of the ribbon vibrator of the same typewriter, and its controls, showing keyboard control of the ribbon-field selection, coordinated with a pair of backspace keys.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1 of the drawing, the typewriter is shown with its outer casing parts removed, for clarity of illustration. The frame 10 of the machine supports a rotatable paper platen roller 12 having control knobs 14, and the usual paper bail 16. Impression paper is fed by rotation of the platen roller 12 as usual, but the platen 12 does not move laterally of the machine. The single-element printing member is shown as the usual truncated sphere 18, mounted on a traveling carriage or carrier 20 to swing towards the impression paper for printing through a ribbon 22 wound on reels in a removable ribbon cartridge 24, and guided near the printing point through the usual guides and vertical ribbon-vibrator 26. All of these printing parts travel across the impression paper as the carriage 20 steps by letter-space increments under control of the usual keys 28. Besides the character keys 28, the keyboard is provided with a pair of backspace keys 30 and 32, a space bar 34, shift key 36, carrier-return key 38, and other usual typewriter controls.
The ribbon cartridge 24 contains a ribbon 22 such as a black, or black and red, or black and correction, or other combination of sections as well known in the typewriter business. Either an upper or a lower portion of the ribbon 22 may be caused to be thrown up into position between the font element 18 and the impression paper, the selection heretofore being made by the manual adjustment of a control lever or knob which is positioned at the front of the traveling carrier 20. For use in the present invention, however, this ribbon-field selecting control is terminated not in a manual lever or knob, but in a split or bifurcated piece 40 adapted to straddle, and to slide along, a longitudinal control rod 42 mounted at either end upon swinging cranklike levers 44 and 46. The latter are pivoted upon suitable fixed supports 48 and 50 secured to the fixed frame 10 of the machine, and at the right-hand end, for example, the crank lever 46 is secured on a stub shaft 52 to which is fastened a control plate 54 by which the position of the control rod 42 can be altered, towards or away from the ribbon cartridge 24. The plate 54, therefore, serves to position the bifurcated piece 40 and hence to select the vertical throw of the ribbon vibrator 26.
At the far end of control rod 42, the crank lever 44 is pivoted on the support 48 as by a stub shaft 56 secured to the rod 42, and carrying a detent lever 58 having a pin or knob 60 that cooperates with a detent spring 62 fastened to the typewriter frame 10 and shaped to establish limits to the position which control rod 42 can take with reference to the path of travel of carrier 20. These positions correspond to adjustment of the ribbon vibrator 26 so that its vertical throw will bring either a higher or a lower segment of the dual ribbon 22 into use for each character printing operation.
FIG. 2 of the drawing better illustrates the construction of the traveling carrier 20 and parts associated therewith, and their relation to the paper platen 12, as well as the manner of operation of the vibrator control linkage. The carrier frame is indicated at 64, guided for motion parallel to the writing line on the impression paper by parallel shafts 66 and 68, the latter of which has a splined connection with a cam 70 whose rise provides the upward throw of the ribbon vibrator 26 in synchronism with the imprinting motion of the single-element printing font member 18. Specifically, the vibrator 26 moves from the position shown in full lines to the upper position (in dotted lines) by virtue of the parallel-linkage arms 72, 74 pivoted at their left ends on a depending lug 76 beneath the table 78 supporting the ribbon cartridge 24 upon the traveling carrier frame 64. Conventional ribbon-feed mechanism 80 surmounts the table 78.
The vertical "throw" of the ribbon vibrator 26 results from the upward swinging movement of a plate 82 pivoted on the carrier frame at 84 and held in contact with cam 70 by a spring 86. The motion of plate 82 is transmitted to one of the parallel-motion arms 72, as indicated by dashed-line positions of these parts in FIG. 2, through the interposition of a control rod 88 whose right end passes beneath the arm 72 and into a slot 90 of the plate 82. The position of the control rod 88 along the slot 90 governs the rise of the vibrator 26, because that position determines the distance that the point of application of the lifting force is spaced from the pivot axis of arm 72. The position of control rod 88 is, in typewriters of this kind as heretofore made, controlled by a manually operable knob or the like mounted on a mechanism table 92 secured to the traveling carrier 20. In the present construction, the control rod 88 is connected by its clevis 94 to a crank 96 pivoted at 98 to the table 92 or to a lug 100 depending from said table 92, or to any other fixed part of the carrier frame 64.
The upper end of crank 96 terminates in a bifurcated formation 40 here represented as a pair of depending fingers 102, 104 which can be bent, or otherwise adjusted with reference to the body of the crank 96, and which straddle or encompass the longitudinal control rod 42 already described as extending along and parallel to the path of travel of the carrier 20. The way in which a limited motion of control rod 42, to the right in FIG. 2, will shift the right end of control rod 88 to the right in slot 90, to produce a smaller vertical lift of the ribbon vibrator 26, will be obvious. It is also obvious that this control arrangement will operate for all positions of the carrier 20 along or parallel to the writing line of the machine, without interference with the usual spacing and backspacing (or carrier-return) movements.
FIG. 3 of the drawing shows more clearly the essential parts as described above, and also a convenient way in which control of the throw or lift of the ribbon vibrator 26 is coordinated with the operation of one or another of the two backspace keys 30, 32 of the typewriter. The parts of the parallel-arm linkage 72, 74 and 76 described above are duplicated at the opposite side of the ribbon vibrator 26 as indicated by the corresponding numerals with prime marks appended. The other parts described are identified by the reference numerals mentioned above, as are the two backspace keys 30 and 32. The keylevers of these backspace keys 30, 32 independently control, through linkages of conventional construction at 106 and 108, the carrier backspacing mechanism 110, which may be as described in the Palmer patent mentioned above. In addition, the respective backspacing keylevers are linked, as by bent control wires 112 and 114, to portions of the control plate 54 that lie on opposite sides of the fulcrum defined by the stub shaft 52 of the crank arm 46.
For adjustment purposes, the upper ends of the control wires 112 and 114 are shown as threaded, and they pass loosely through holes in the opposite ends of control plate 54 to provide a lost-motion connection thereto. In the position shown in FIG. 3, backspace key 32 was last depressed, tipping plate 54 clockwise, and shifting control rod 42 to its left-hand position, to move control rod 88 into the full-line position marked "H" on the ribbon vibrator arm 72, so that the lower section of the ribbon 22 will be used. When the other backspace key 30 is depressed, control plate 54 will be rocked counterclockwise, moving rod 42 to the right, and adjusting the control rod 88 to the "L" position, providing for use of the upper section of the ribbon 22. In this way, the selective use of a printing ribbon segment, or a correcting ribbon segment, is coordinated with the use of a selective one of the two backspace keys 30, 32 as described in connection with other kinds of typewriters in my patents mentioned above.
As a convenience in adjusting the amount of "throw" of control rod 42 produced by the operation of the backspace keys 30, 32, locknuts 116 and 118 are shown as engaging the threaded upper ends of the control wires 112 and 114. It will be understood, by those skilled in the art, that in mass production of typewriters including this invention, other and less cumbersome means may be substituted for the making of such adjustments.