US2909996A - High speed printing mechanism - Google Patents

Description

Oct. 27, 1959 c.. J. FITCH HIGH SPEED PRINTING MECHANISM 5 Sheets-Sheet 1 Filed Feb. 13, 1957 INVENTOR.` Y CLYDE J. FlTcH BY /J 1 AGENT l c. J. Fn'cH HIGH SPEED PRINTING MECHANISM Oct. 27, 1959 5 Sheets-Sheet 2 Filed Feb'. 13, 1957 Oct. 27, 1959 C.

. HIGH SPEED Filed Feb. 1s, 1957 J- FIT PRINTING MECHANISM A CH I 2,909,996

5 Sheets-She-et 3 Oct. 27, 1959 yc:. FITCH 2,909,996

HIGHSPEED PRINTING MECHANISM Filed Feb. 15, 1957 1 5 Sheets-Sheet v4 FIGA oct. 27, 1959 C, FITCH 2,909,996

HIGH SPEED PRINTING MECHANISM File'd Feb. 13, 1957 5 Sheets-Shet 5 DRIVERS SENSE /102 L AMRUFIERS 105 108A?? LswlTcl-HNG MATRlx SYNcHRoN1z- 1 |111107 |NG C|RCU|TS \-|w-J 1NRUT DATA 112 CHANNELS CHARACTER FoRM1NG S|GNA1 E 1 1NES FROM SENSE AMPLlFlERS v "All IIB" "CII [loll l [111| [19H EIG'- '7 INPUT DATA CHAN NEL TO COLUMN COLUMN NO. 1

NO. 1 DRIVER United States Patent F"ice l2,909,996 uren SPEED rimorso MECHANISM Clyde J. Fitch, Endicott, N.Y., assignol'. to, International Business Machines Corporation, New York, N.Y., a corp'or'raitiolrl of New York Application February 13,1957, Serial No. 639,988 8 (C-l. Ylill- 93) This invention relates 'to a high speed printing mechanism, and particularly to an improved facsimile-type printing mechanism for mechanically printing at relatively high speeds', in olosely-spaced'multiple columns, on a moving record medium.

Previously proposed fragmentary or facsimile-type printers have been limitedy usually to single column printing, or transverse printing on paper tape, since the mechanism occupied so much space that multiple column printers were not feasible. The advantage of fragmentary or facsimile printing'includin'g higher possible speeds, fewer problems of paperhandlir'ig and feeding, and less complexity, make such printers worthwhile for multiple column printing, provided that a low-inertia high speed mechanism can be employed lat relatively close column spacings, say, for example, of the order of /lo inch.

A"principal object of this invention, therefore, 'is to provide an improved printing mechanism for mechanically printing at relatively high speeds, in closely `spaced 'multiple columns, on a moving record medium.

A further object of the invention is to provide an improved printing fnechanism in 'which a plurality of closely spaced printing anvils which cooperate with a plurality of y rotating helices, are operated at relatively high printing rates by electro-adhesive clutch assemblies.

Another object of the invention i's to provide an improved printing mechanism in which a plurality of aligned closely spaced printing anvils, which cooperate with'a plurality of rotary helices, are operated by electrostatic clutch means under the selective control of signals generated in ls'ynchronis'm with the rotation of the helices.

Another object of the invention is to provide an improved printing mechanismr including a continuously rotating shaft carrying a plurality of helically arranged printing surfaces, means for generating spaced electrical pulses corresponding to the fragmentary elements of characters to be printed, and a plurality of electrostatically operated printing anvils governed by these signals for impelling a continuously moving record medium against the helices for printing.

A further object of the invention is to provide an improved high speed printing mechanism.

Briefly described, lthe invention contemplates a printing mechanism in which a plurality of helically arranged printing surfaces are provided on a continuously rotating shaft, the helices being suiiicient in length to span the entire number of parallel columns to be printed. The continuously rotating'helix shaft is mechanically synchronized, as by suitable gearing or timing belts, to a suitable paper feed, so that 'the record medium, such as a continuous paper form, is passed over the rotating helicesv at a constant rate with respect to the rotational speed of the helices. Preferably nine helices are provided lon the shaft, seven of which are used for character formation and twp of which are unused for printing but which represent the vertical space between characters. Viewed from a line in the same plane as the axis of the helix shaft, the rotation 'of the shaft through one 'revolution 'causes seven horizontal'printing scans in succession at any given point, plus two successive scans provide spacing between lines. The vertical vmotion yof the paper 'or record medium' past the helix shaft provides a vertical scanning. Printing. is then accomplished by providing, at each horizontally disposed printing location or colum'nar position, a printing bar oranvil which is selectively governed to be' impelledagain'st the record medium 'and vthe helices, with suitablec'arbon backing, inked ribbon or other ink transfer material disposed between 'the record medium VVand the aliyil, or between the 'record medium andthe helices. Each "of the `printing anvils is arranged -for longitudinal {rave'l toward and away from the helix shaft, wtha 'suitable ybiasing spring provided for each anvil and arranged to b ias the anvil to its normal non-printing position. 'anvils are'rnov'ed through their printing strok'eby the operation of a multi-band electrostatic clutch, in which 'a plurality of 'conductive bands, one for each 'printing anvil, partially encircle a constantly 'revolving electrostaticclutch drum, with each handhaving one Aend thereof in'sulatedly attached to 'the associated printing anvil, 'and having'fhe other end attached to a light connecting spring, which serves tornan;- tain the band in position yand to establish an electrical `'connection thereto. llt/hen a suitable voltage pulse is applied to create a potential difference between the band and the clutchvdr'um," an electro-adhesivo force of l@considerable magnitude is developed, so that the energized band adheres' to 'the drum 'surface and 'is carried along with the' jdrum. Thus,'the printing anvil isv impell'ed toward the heliX record medium, to the fo'rward'limit fof the anvil :stro-lie, determined 'either by suitable stops or by impact with the record medium backedlby the helix, in responseto voltage pulses supplied to the associated electrostatic clutch band. f

The signals vforoperating the .printing anvils are derived from suitable signal'gehera ing means, 'synchronized with the' rotation of the helix shaft. At the 'relativelyhig'hrspeeds'at which nnseonstruqed 'in accordance with this invention ar nte,v de to operato, ige., '5000 or' more llines rj minute, 'the signal generating means preferably oompfises a mgm-assolo drum either mounted Vdirectly on `thehelix shaft or synchronized for rotation therewith 'alt a 1;l ratio', with permanently `disposed magnetic intluenc'e spots or locations provided thereon inl character `syrlthesizing tracks, one Such track being provided for each character which'is to be printed. A magnetic pick-'up'head is provided, one for each character track, which is'eifective to generate electrical impulses in response to the magnetic'nintluence spots or locations passing the pick-up head. Thus, the necessary signals for forming each character are available during each revolution of the helix shaft, i These signals are supplied to the electrostatic clutch bands by suitable selecting circuits, governed by signals such as might be supplied from a calculator output, for example, so that'each `columnar position which'is to be printed is supplied with the appropriate signalsl for operating the printing anvil. Because ofthe few moving parts, and the small size and weight lof 'the reciprocable printing anvils and the associati-dolmen bands, the mechanism vis capable of operation at yery' 'high printing rates. The use of amulti-band electrostatic clutch fas an electrically controlled actuating Vinear'ls for the printing'anvil enables a large 'number of printing positions to be provided in a small space, for example, the printed characters may be of the order of Patented Oct. 27, 1959 3 IAO inch in width or less, so that 120 printing positions would occupy 12 inches of space, including the accumulated space between printing positions, i.e., intercolumn spacing.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of examples, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a diagrammatic isometric view of the' general assembly of a high speed printing mechanism, in accordance with a preferred embodiment of the invention.

Fig. 2 is a diagrammatic isometric view of a portion of the apparatus of Fig. 1,-showing in greater detail the relationship of the printing anvils, clutch bands and printing cylinder.

Fig. 3 is a diagrammatic cross-sectional view of the portion of the apparatus shown isometrically in Fig. 2.

Fig. 4 is a diagrammatic representation of the manner in which a letter A is printed by the subject printing mechanism.

Fig. 5 is a diagrammatic sectional view of the magnetic drum, showing the disposition of the characterforming magnetic influence locations on the drum for generating the signals required to print the letter A.

Fig. 6 is a schematic illustration of one form of electrical control system which may be employed, and

Fig. 7 is a schematic illustration of one suitable arrangement for the switching matrix indicated generally in Fig. 6.

Referring now to Fig. 1, there is shown a first and a second side frame 1 and 2, respectively, held in a suitably spaced relation by a bottom or base plate 3. Additional cross bars or separators, not shown, may be employed as desired to provide suitable rigidity and proper spacing of the side frames 1 and 2. Several shafts are journaled in suitable bearings in the side frame, and may be designated as the paper or forms feed shaft 5, the helix or printing cylinder shaft 6, and the clutch drum or rotor shaft 7. The paper feed shaft 5 and the helix shaft 6 are mechanically connected by the gear 8 and pinion 9, as shown, so that the paper feed shaft rotates at a selected integral sub-multiple of the number of revolutions of the helix shaft 6, for purposes to be explained subsequently. Alternatively, a suitable pulley and belt arrangement may be employed to mechanically synchronize the shafts 5 and 6. It will be noted that shafts S and 6 are counterrotating, as indicated by the directional arrows on gear 8 and pinion 9.

Suitable driving means, such as the motor 11, directly connected to one end of shaft 6, is provided to drive the shafts 5 and 6 at substantially constant rotational speeds, but other mechanical driving arrangements may be employed, as will be apparent to those skilled in the art.

A drum 13, having at least a peripheral or outer layer of magnetizable material, is provided and arranged to rotate in a 1:1 ratio, in synchronism with the helix shaft 6. Although the drum may be mounted on a separate shaft, mechanically synchronized with shaft 6, the preferable arrangement is to mount the drum on shaft 6, as shown in the drawings, thereby insuring accurate and continuous synchronization of the drum speed and helix shaft speed. A plurality of magnetic sensing heads 15 are associated with the drum, in a manner and for purposes which will be subsequently explained.

Mounted on helix shaft 6 is a printing cylinder 17 having a plurality of helical surfaces 18 thereon, which may be obtained, for example, by winding high strength steel wire, e.g., music wire, in grooves cut in the surface of the cylinder, withl the ends of the wire anchored n the castellated ends of cylinder 17.

The record medium, or paper form is fed from below upward over the printing cylinder 17, and may be pro- 4 vided with edge perforations or feed holes as shown, which engage suitably spaced pins on an enlarged portion of paper feed shaft S. Although any type of impression sensitive combination of record medium may be used, the arrangement shown here comprises a carbon sheet 19, backed by a paper sheet 20. Suitable means, not shown, may be provided for separating the carbon sheet from the paper sheet after printing. Arrangements using inked ribbons, carbon ribbons and the like may obviously be employed, as well as suitable multiple sheet arrangements for producing copies of the printed material concurrently with the original.

On shaft 7 there is mounted a cylindrical rotor 21 comprising a hub or spider portion 22 of conductive material, having thereon an outer layer 23 of semiconductive material, which may consist of material compounded and manufactured as explained in a copending application for Letters Patent of the United States, Serial Number 630,319, tiled on December 24, 1956, for Electro-Adhesive Materials and Method of Manufacture, and assigned to the present assignee. As explained in this copending application, material of this type, in combination with conductive material, forms an excellent electro-adhesive combination. Shaft 7 and rotor 21 are rotated at a substantially constant and relatively high speed by suitable driving means, such as a motor 25, in the direction indicated bythe arrow. Rotor 21, as well as printing cylinder 17, are co-extensive and are at least as long as the number of columnar printing positions to be provided. For example if columns are to be provided for, with each character position having a width of 0.10 inch, then the over-all length of printing cylinder 17 and rotor 21 would be not less than 12 inches.

Mounted above clutch rotor 21 and aligned horizontally with printing cylinder 17 is a printing anvil assembly, including a plurality of printing anvils 27, which are carried in front and rear guide bar assemblies 28 and 30 respectively, so that the printing anvils can be moved toward and away from the record medium and printing cylinder. A plurality of biasing springs 32 are carried by a spring mounting bar assembly 33, so that the lower ends of springs 32 are operatively connected to printing anvils 27 to bias them to a normal position away from the record medium and printing cylinder.

Each of the printing anvils 27 has associated therewith a clutch band 3S, one end of which is attached to, but insulated from, the printing anvil, as by use of a suitable insulating cement. The other end of each clutch band is resiliently connected to an anchor point, as by the wire springs 37, which have a hooked end engaging thc lower ends of bands 35, and which are anchored in a suitable spring support 39, formed of insulating material and extending from one side frame to the other. Suitable electrical terminations are provided for each of the connector springs 37, for purposes to be described subsequently. To provide a clean lubricated surface on the electro-adhesive rotor material 23, a lubricant reservoir 41 is provided, having wicking 42 therein which rubs on the surface of the rotor and continuously supplies a suliicient amount of lubricant to the surface of the rotor.

Fig. 2 of the drawings illustrates in detail the relationships of the printing anvils and their associated clutch bands, biasing and connecting springs, with respect to the printing cylinder and clutch rotor. As seen in Fig. 2, the biasing springs 32 may comprise a plurality of projections from a common strip of suitable spring material, formed in a comb-like fashion. The springs 32 are prestressed so that their lower ends engage one vertical face of projections 45 on the printing anvils 27, the opposite face of these projections engaging the cap bar 29 of the front guide bar assembly 28 to act as a back stop, thus defining the normal or non-printing positions of the anvils 27. The manner in which the front and rear guide bar assemblies 28 and 30 are slotted to act as guides for the printing anvils A2 7 is apparent from this drawing.

AIl

n Fig. 2', it will be noted that the striking en'd of the Vprinting anvils 27, that is, the end which is nearest the printing cylinder is slightly' twisted or skewed at`a sm'a'll angle with respect vto the-,axis Iofthe printing cylinder. This' skew compensates for the` motion of the paper during printing, in a manner to be Asubsequently-explained.

'The clutch bands 35 are show n in Fig. V2, as attached to the printing anvils by a thin layer of insulating cement, so that they are enabled to' transmit driving force to the printing anvils but are electrically insulated therefrom. The bands are shown as having'substantially 90 degrees of wrap -around the Lclutch rotor. "ihe other ends of bands 3,5 have small holes or openings punched or other- Wiso formed therein', with the hooked ends of Springs 37 passing therethrough. The springs 37 are anchored in any suitable manner to the bar 39, .of insulating material, Suoh as by tho'thtoadod studs 47., and the damping pieces 49, which not only serve to hold the springs in place but also provide a means for making separate electrical connections to each of the springs 37 and hence the clutch bar-lds 3.5.

Eig. 3 further illustrates the relationship of the parts described in detail in Fig. 2, and particularly shows the alignment of the printing anvils 27 with the axis of the printing cylinder 17. The manner in which the projections 45 on printing anvils 27 act as back stops and engaging points for biasing springs 32 is clearly seen in this drawing. Also, the manner in which, for each spring 37, a wire 5.1, provided with -a suitable tapered plug, is engaged with stud 47 to provide an electrical connection is manifest from the drawing.

With the clutch rotor continuously rotating in a clockwise direction as indicated by the arrow,'a residual drag or frictionY exists between `the clutch band and the surface o f the rotor.V Biasing spring 32 is stressed to exert suicient lforce to overcome this residual drag, So that normally the clutch bands and printing anvils occupy the position shown. When a voltage pulse is supplied to a clutch band via the wire 51 and spring 37 associated with a particular band,`so that a potential difference exists between the end 35 and the scrniconduct-ive material 23, electro-adhesive force is developed which causes the clutch band to adhere to the surface of the rotor, and with a force sufficient to overcome biasing spring 45. Accord- `ii'lgly, the printing anvil is pulled to the right, as viewed in the drawing, forcing the record medium against the helical surface of the printing cylinder to `cause a printing impression. At the forward limit of its motion, the printing anvil is stopped by the/record medium and the helical surface of the printing cylinder, although a forward motion stop similar to the back stop 45 may be provided if desired. The clutch band then slips uponV the surface of the clutch rotor until the termination of the voltage pulse, if it is still in effect, whereupon the biasing spring restores the anvil to its normal position. By making the-l control pulses Vsufficiently short in duration, however,A the electro-adhesive force may be terminated at or shortlyA before the printing anvil reaches its forward limit, so -tha-t any rebound effect as the result of the stroke will enhance the return action.

"Fig 3 also shows the manner in which the wicking 42 in reservoir 41 wipes on the surface of the clutch rotor to provide a clean lubricated surface.

It will be apparent from the foregoing description that the' mechanical arrangement of Vtheparts is'such that high operating speeds and close columnar spacing are readily achieved.' The only parts subject to acceleration and deceleration during printing operations are the printing anvils, clutch bands and associated'springzs, and these maybe made' relativelyv small and'light in weight, so that they may be operated rapidly. The rotating parts rotate at substantially constant velocity'during"printing, hence no large decelerating or accelera-'ting forces are required, and relatively small driving motors' may'beusedl 'The 6 use of. narrow olutoh hands in a multi-band electro-adhesivo clutch enables vorytsmall spacings to be. obtained for the printing positions. a feat not readily accomplished with ani/'other' typo' .of yhighy speed 'electromechanical transducer.

Having thus described the mechanical features `of the invention, the manner in which appropriate voltage pulses are derived forl the control 'of the printing operations will now be made clear. 'As stated previously, a plurality'of successive horizontal scannings of each .character position are effected during `each and every revolution of tho printing -oylindon Although the number may be varied as desired, 'the' drawings "illustrate nine hel-ixes, formed yby nine wires helically 'wound on the Cylinder 17, as may be. soon in Figs: 1. 2 and 3. Thus, nine horizontal scans are providedin the disclosed ernbodirnent ofthe invention, sinceeach of the nine helixes Provides a horizontal scan, at eachA and every' Column position. Since the paper -is also moving vertically, the equivalent of vertical scanning is also provided, by causing the record medium to advance through one vertical character space plus Vertical margin'for each yrevolution of the printing cylinder. Only seven of the nine horizontal scans are employed for printing, the remaining two occurring during the vertical spacing between rows of printed characters on the record medium. Accordingly, after the start of a printing cycle a row of one or more dots or impressions may be made during any one of the horizontal printing scans, and by proportioning and arranging the spacing of the helices vwith respect to the width of the printing anvils, similar scans occur concurrently at all printing positions.

An example of the manner in which a character may be built up* by operation of a printing anvil at various times during one revolution of the printing cylinder is illustrated in Fig. 4. The successive horizontal scans of the nine helix wires on the printing cylinder passing each of the printing anvils occur in successions from top to bottom, since the paper is continuously moving upward, and are designated by the reference characters S1 through S9, respectively.

At a time substantially half-way through the first scan S1, the printing anvil is operated, imprinting a dot designated by reference lcharacter A11; on the second scan S2, two spaced dots designated A21 and A22 are created by two strokes of the printing anvil; on scan S3, dots A31 and A32 are imprinted; and so on for all seven of the printing scans, the first digit of the reference character for each dot indicating the number of the scan during which printing occurs, and the second digit indicating the order of printing Within the scan. The letter A is thus created by the successive dot printing on the successive scans. The illustration in Fig. 4 is drawn to a large scale for clarity, and when reduced to actual size, say, for example, a maximum width or" .010 inch and a total scanning lengt-h of .018 inch, a relatively solid appearing character is obtained. VFrom this one example, it will be obvious how any number of congurationstmay be printed to provide `different alphabetic, numeric, and special printed characters.

Because the record medium is in continuous motion, and the successive dots in a given row are spaced apart, it follows that the printing end of the printing anvils must be skewed as shown in Fig. 2, to compensate for the paper' travel occurringv during the printing of a row of dots.

To operate the printing anvils at the proper time during each scan to produce characters -in-the manner described above, suitable character-forming signals are obtained from the magneticdr'um 15. As initially stated, a character-forming signal track is provided for each character which may be printed, for/example if the nurnber lof possible characters to be printed' comprises twentysix alphabetic, ten' numeric, andftwelve special characters such as punctuation marks, dollar sign, then a tot'alv of forty-eight character signal tracks are provided on the drum. Each track is provided with a plurality of positions or locations which are effective to produce a voltage pulse in the sensing head 15 associated with the track as the positions or locations pass by the sensing head. These positions or locations may comprise discrete magnetized spots on the surface of the drum, or may be etched or milled grooves, but in either instance, produce a magnetic liux change which is utilized to generate a character-forming signal or pulse. Fig. shows the distribution of the magnetic influence locations for the character track which provides signals for generating the letter A. The drum is shown at the start of a scanning cycle, the reference point being an air gap 5S of sensing head 15. The first magnetic influence location to pass air gap 58 is designated by reference character` M11, indicatingthat it is the first magnetic influence provided during the first horizontal scan (S1 of Fig. 4). M21 and M22 are the first and second magnetic inuences occurring during the second scan S2 of Fig. 4, and so forth for the remaining scans. It will be evident from inspection of Figs. 4 and 5 that the characterforming signals supplied from the sensing head for the track configuration shown in Fig. 5, will, if utilized to govern the operation of one of the printing anvils, produce the letter A as shown in Fig. 4. The tracks on the drum for producing the character-forming signals for the other characters to be printed will be formed in a similar manner, by providing magnetic influence positions which will cause the generation of pulses at proper times during the printing scans.

Having thus described the mechanical features of the printing mechanism and the manner of generatingr the required character-forming signals, consideration will now be given to one suitable form of electrical circuitry for controlling the operation of the printing mechanism, whereby input data in the form of electrical signals is printed on a record medium.

Fig. 6 is a schematic illustration of suitable circuitry for governing the supply of character-forming signals from the drum heads to selected ones of the electroadliesive clutch bands in response to input data. The character-forming signals, in the form of voltage pulses generated in sequences as previously described, are supplied from the sensing heads 15 over lines 101 to suitable amplifiers, indicated generally by the rectangle 102, which may be conventional pulse amplifiers, and which function to amplify the relatively Weak signals generated by the sensing heads to a voltage and power level sufficient for the necessary switching of the signals with the input data. From the output of the sensing amplifiers, the amplified character-forming signals are supplied over lines 104 to a first set of input circuits of a switching matrix, designated generally by the labeled rectangle 105. A second set of input circuits for the matrix 105 is connected to the input data channels, designated generally by reference character 107. It is assumed, for purposes of illustration only, that the input data is in the form of electrical pulses present on input signal lines, a plurality of such lines comprising each of the input channels. One such channel is provided for each column position in the printing mechanism, e.g., 120 input data channels for 120 columns of printing. Input data to be printed in any particular row is presented simultaneously by al! input data channels representing the columns in the row which are to have a character printed therein, by simultaneous existence of signals on one or more input signal lines in each of the channels. Such an arrangement for handling data is known in the art as a parallelparallel arrangement. Although other arrangements may be designated to operate with this printing mechanism, the parallel-parallel system affords `the highest speed and relatively simple circuitry, even though a relatively large amount of electrical or electronic components are required.

The outputs of the switching' circuits in switching matrix are supplied to a plurality of output lines 108, of which there is one for each column position in the printing mechanism. 'Ihese output lines are connected to the inputs of a corresponding number of driver stages, indicated generally by the labeled rectangle 110, and which may be any suitable type of amplifier which provides an output suicient for proper energization of the electro-adhesive clutch bands 27, which, as shown by the drawings, are connected to the outputs of the drivers by lines 111. The electrical connections to the bands may be most readily made as described in connection with Figs. 2 and 3, but in Fig. 6, the connections are illustrated schematically for the sake of clarity. The shaft 7, and hence the semiconductive material 23 of clutch rotor 21 are at the same potential as the frame, and are preferably at ground potential, in other words, with no potential difference between the clutch rotor and other exposed non-insulated portions of the mechanism so that no electrical shock hazard is presented.

Although either positive-going or negative-going pulses may be employed to represent the presence of a signal, it will be assumed for the purposes of this description that the presence of a signal will be indicated by a rise in voltage on the line or device in question.

Considering the operation of the arrangement shown in Fig. 6, the continuous rotation of shaft 5, and hence printing cylinder 17 and magnetic drum 13, produces the scanning sequences previously described, so that during each and every revolution of printing cylinder 17 nine horizontal scanning sequences are performed by the helices of cylinder 17, at each and every column position. During the first seven of these sequences, used for printing, each of the character-forming tracks on drum 13 causes the generation of character-forming signals by sensing heads 15, which are amplified and supplied to the first set of inputs of the switching matrix 10S via lines 101, amplifiers 102, and lines 104. Accordingly, the necessary character-forming signals for forming each and every character which it may be desired to print are supplied to the one input of the switching matrix during each and every revolution of the printing cylinder. It then remains to select these character-signal sequences in accordance with those columns where the character is to be printed. This switching is carried out by whatever type of switching circuits are employed in matrix 105, under the control of the input data channels 107. The appropriate characterforming signals are then supplied to the clutch bands 27 via lines 10S, drivers 110 and lines 111, to raise the selected bands, at the proper printing time, to a relatively high voltage above ground, or the potential of rotor 21, so that the clutch band adheres to the rotor, and causes the printing stroke of the associated anvil.

For synchronizing other apparatus with the operation of the printing mechanism, a separate track may be used on the drum to supply pulses to appropriate synchronizing circuits, illustrated generally by the labeled rectangle 112.

Many types of switching circuits and devices may be employed in the switching matrix 105, including vacuum tube switches, magnetic core switches, transistor switches and diode switches, and the invention is not limited to use with any particular type. For the sake of example, however, Fig. 7 shows a partial schematic diagram of the manner in which the matrix 105 may be embodied, using conventional diode logic circuits.

In the diode logic shown in Fig. 7, a triangle represents, symbolically, two or more diodes arranged to function as a logical And circuit, or coincidence circuit. These circuits are constructed and arranged so that, when and only when input signals are simultaneously present at all of the inputs represented by the cocasse f lines entering the base of the triangle, Will an output signalbe provided at the output, shown symbolically as leaving the apex of the triangle.V A logical Orcircuit, or mixer circuit is represented by a plano-convex or half-moon* symbol fon the drawings, and is constructed and arranged so .that a signal present on any one of the input lines, entering the base of the symbol, will provide'a'n output signal at the output, indicated symbolically `by the line leaving the curved side of the symbol.

An input data channel 167,. corresponding to one of the plurality of channels shown in Fig. .6, ,and referred to as the input data channel, column .#1, is shown as comprising seven'individu'al input signal lines designated by reference character 113, and the combinations of signals existing on these linesat any onetime may be used to designate theV various characters to be printed in the first column position. More or less channels may be employed depending upon the coding system, and the subject invention isY not limited to use with any `pa'ryticular arrangement.

Whatever code is used in .the input channel is translated by means of a translator 115, which may take any one of a number of well-known forms, and is eifective to translate the incoming data signals in the associated channel to a voltage on one of a plurality of input character signal lines, vone for each character represented by the incoming data. Six such lines are illustrated in Fig. 7, designated by reference characters 117, 118, 119, 120, 121 and 122 respectively, and .representing the characters A, B, C, 0, l and 9 respectively, supplied as input data. Y

These signals are combined with the corresponding character 'forming' signals on lines 104 from the sense amplifiers in diode And circuits, in a one-to-one correspondence. For example, if an A is to be printed in column l, then the A7 line 117' from the translator carries'a positive signal, andthe And circuit 123 is enabled to passthe' character-formingsignals from the A lineu 104 via a connection 1.24 to one'of the inputs of the -Or circuit 125, whence they are supplied via the line 108 to the driver for column l. A similar switching -action is provided for each of the readingcharacters to be'printed in column'l, and such a switching arrangement is duplicated foreach column position.

From theforegoing, it can tbe seen that a printing mechanism constructed in accordance with this invention is capable of operation at relatively high printing speeds, and with relatively close columnar spacing, with a small light-weight movable printing anvil or bar provided for each position, which with-its associated parts, are capable of very high operating speeds.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied 'to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustratedand in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed isi l. ln combination, a printing cylinder having a plurality of helical printing surfaces thereon, at least one printing anvil disposed for movement toward and away from said cylinder, means for normally biasing said anvil away from said cylinder, a rotor of electro-adhesive material disposed adjacent said printing cylinder and coextensive therewith, a band of conductive material, one for each of said printing anvils, having one end attached to the printing anvil and having the other end resiliently connected to an anchor point, the band encircling at least a portion of the periphery of said rotor, so that said printinganvil is impelled towardsaid cylinder t print on a record medium disposed between Said anvil and said cylinder r.when Va voltage pulse' establishes a potential difference between said rotor and said band, fnd means for selectively energizing .said bands in accordance with the characters to be printed.

2J In combination, a printing ,cylinder havillg l Plurality of helical printing surfaces thereon, at least one printing anvil disposed for movement toward ,and away from said'cylinder, means 4for normallybilasing vSaid all' vil away from said cylinder, a' rotor of electro-adhesive material disposed adjacent saidrprinting cylinder and c9- extensive therewith, ia band of conductive material, .011e for each of said printing anvils, having one end attached to the printing anvil and having .the other .end resiliently connected to an anchor point, the band encircling atleast a portion of the periphery of said rotor, so that saidnrinting anvil is irnpelled toward said cylinder'to print on a record medium disposed between lsaid anvil and ,said cylinder when a voltage pulse establishes' a potential difference between said rotor and said band, vmeans for generating character-forming 'signals jin synchronisrn with .the rotation of said cylinder, andrneans responsive to vinput data to be [recorded vfor selectively energizing ysaid band from said generating means.

3. In combination, a printing cylinder having a yplurality of helical printing 'surfaces thereon, at least one printing anvil disposed for movement toward and away from said cylinder, means for normally biasing said -anvil away from'said cylinder, a rotor of electro-adhesive material disposed adjacent said printing cylinder and coextensivc therewith, a vband of lconductive material, one for each of said printing anvils, having one end attached 'to .the printing anvil 'and having'the other end resiliently inder, a plurality of magnetic signal tracks carried .by

said magnetizable means', one such track being provided foreach character which is to be printed, permanently existing magnetic influence positions disposed on each track Arepresenting character-forming signals required `to form the character for that track, a` sensing 'head for each track effective to generate character-forming voltagevimpulses in response' to said magnetic influence position, and means for utilizing said voltage impulses to energize said bands to thereby selectively print said"cl:taracters'.A

4. yIn combination, a printing cylinder having a vplurality of helical'printing surfaces'thereon, atleast one printing anvil disposed for movement toward and away from said cylinder, means for normally biasing said anvil away from said cylinder, a rotor of electro-adhesive material disposed adjacent said printing cylinder and coextensive therewith, a band of conductive material, one for each of said printing anvils, having one end attached to the printing anvil and having the other en'd resiliently vconnected to an anchor point, the band encircling at'least a portion of the periphery of said rotor, so thatsaid printing anvil is impelled'toward said cylinder to print on alrecord medium disposed between said anvil and said cylinder when a voltage pulse establishes a potential difference between said rotor`and said band, and signal generating means for selectively energizing said bands'vin accordance'with the characters to ,be printed, said signal generating `'means compiising ymagnotizable Ymeans' ai"- rangedfor rotation in Ys', 1ncl:lrcn1isrn with saidgprinting cylindenaplurality of ,magneticsignal vtracks carried. by said l 1 each character which is to be printed, permanently existing magnetic inuence positions disposed on each track representing character-forming signals required to form the character for that track, a sensing head for each track etective to generate character-forming voltage impulses Vin response to said magnetic influence position, an input vprinting anvil disposed for movement toward and Vaway from said cylinder, means for normally biasing said anvil away from said cylinder, a rotor Aof electro-adhesive material disposed adjacent said printing cylinder and co-extensive therewith, a band of conductive material, one for each of said printing anvils, having one end attached to the printing anvil and having the other end resiliently connected to an anchor point, the band encircling at least a portion of the periphery of said rotor, so that said printing anvil is impelled toward said cylinder to print on a record medium disposed between said anvil and said cylinder when a voltage pulse establishes a potential difference between said rotor and said band, and signal generating means for selectively energizing said bands in accordance with the characters to be printed, said signal generating means comprising magnetizable means arranged for rotation in synchronism with said printing cylinder, a plurality of magnetic signal tracks carried by said magnetizable means, one such track being provided for each character which is to be printed, permanently existing magnetic inuence positions disposed on each track representing character-forming signals required to form the character for that track, a sensing head for each track effective to generate character-forming voltage impulses in response to said magnetic inuence position, an input data channel carrying electrical input signals representing the characters to be printed, one such channel being provided for each column to be printed, a plurality of character signal lines, one associated with each of said sensing heads and carrying character-forming voltage pulses, and switching means governed by said electrical input signals for selectively energizing said bands from said character signal lines in accordance with the characters to be printed in different columns.

6. In combination, a printing cylinder having a plurality of helical printing surfaces thereon, at least one printing anvil disposed for movement toward and away from said cylinder, means for normally biasing said anvil away from said cylinder, a rotor of electro-adhesive material disposed adjacent said printing cylinder and co-extensive therewith, a band of conductive material, one for each of said printing anvils, having one end attached to the printing anvil and having the other end resiliently connected to an anchor point, the band encircling at least a portion of the periphery of said rotor, so that said printing anvil is impelled toward said cylinder to print on a record medium disposed between said anvil and said cylinder when a voltage pulse establishes a potential diterence between said rotor and said band, and signal generating means for selectively energizing said bands in accordance with the characters to be printed, said signal generating means comprising magnetizable means arranged for rotation in synchronism with said printing cylinder, a plurality of magnetic signal tracks carried by said magnetizable means, one such track being provided for each character which is to be printed, permanently existing magnetic iniluence positions disposed on each track representing character-forming signals required to form the character for that track,

a sensing head for each track eiiective to generate character-forming voltage impulses in response to said magnetic inuence position, an input data channel carrying electrical input signals representing the characters to be printed, one such channel being provided for each column to be printed, a plurality of character signal lines, one associated with each of said sensing heads and carrying character-forming voltage pulses, and a switching matrix having first and second inputs connected to said character signal lines and said input data channels, respectively, and a plurality of outputs, one for each of said bands, and means for combining the signals supplied to said first and second inputs to supply signals to said outputs for selectively energizing said bands to print selected characters in selected columns in accordance with said input data signals.

7. In printing apparatus for printing at high speeds in closely-spaced multiple columns on a continuously moving record medium comprising, in combination, a continuously rotating cylinder provided with a plurality of helically arranged printing surfaces and extending across the width of the total number of columns to be printed, a plurality of printing anvils, one for each column to be printed, arranged in a line parallel to the axis of said cylinder, said printing anvils being disposed for movement toward and away from said cylinder, said record medium passing between said cylinder and said printing anvils, means for selectively impelling said printing anvils toward said record medium on said cylinder, comprising a continuously running rotor of electro-adhesive material mounted parallel to said printing cylinder and co-extensive therewith, a plurality of conductive bands, one for each of said printing anvils, each of said bands having one end thereof attached to the associated printing anvil and adapted to be electrostatically adhered to said rotor upon the supply of a suitable voltage pulse thereto to create a potential difference between the band and the rotor, whereby the associated printing anvil is impelled toward said cylinder, means for biasing each of said printing anvils to a normal position away from said cylinder, and means for supplying energizing impulses to said bands including signal generating means synchronized with said cylinder rotation for generating voltage pulses in accordance with the information to be recorded.

8. Printing apparatus for printing at high speeds in closely-spaced multiple columns on a continuously moving record medium comprising, in combination, a continuously rotating cylinder provided with a plurality of helically arranged printing surfaces and extending across the width of the total number of columns to be printed, a plurality of printing anvils one for each column to be printed, arranged in a line parallel to the axis of said cylinder, said printing 4anvils being disposed for movement toward and away from said cylinder, said record medium passing between said cylinder and said printing anvils, means for selectively impelling said printing anvils toward said record medium and said cylinder, comprising a continuously running rotor of electro-adhesive material mounted parallel to said cylinder and co-extensive therewith, a plurality of conductive bands, one for each of said printing anvils, each of said bands having one end thereof attached to the associated printing anvil and adapted to be electrostatically adhered to said rotor upon the supply of a voltage pulse thereto to create a potential diterence between the band and the rotor, whereby the associated printing anvil is impelled toward said cylinder, means for biasing each of said printing anvils to a normal position away from said cylinder, means for supplying energizing impulses to said bands including signal generating means synchronized with the rotation of said cylinder for generating voltage pulses representing characters to be recorded, and means for selectively supplying said signals to said bands.

(References on following page) References Cited in the le of this patent UNITED STATES PATENTS Siepmann Feb. 7, 1922 Spencer Nov. 18, 1930 5 Bryce Sept. 1, 1936 14 Paige Nov. 16, 1954 Dumey Aug. 7, 1956 Hartley Jan. 8, 1957 Shepard Apr. 2, 1957 Block July 23, 1957 Devol Oct. 29, 1957

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