US2988987A - High speed printing mechanism - Google Patents

Description

J. LAST 2,988,987

June 20, 1961 HIGH SPEED PRINTING MECHANISM Filed March 1l, 1957 5 Sheets-Shea?I 1 YANES LA ST WMA/ I Pam/ ATTO/ewa@ iJun-e 20, 1961 J. LAsT 2,988,987

HIGH SPEED PRINTING MECHANISM Fileed March 11 1957 v'5:7 Sheets-Sheet 2 1 Il /I ,y F 1,52. 13A

vr: i 30 "lflif; 29 I B2/1 d /zeA JAMES LAST /A/l/EA/,Toe

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June 20, 1961 J. LAST 2,988,987

HIGH SPEED PRINTING MECHANISM Filed March 1l, 1957 5 Sheets-Sheet 3 ITAMES LHST /NVEN WMA/digli (a-JATToRA/f June 2o, 1961 J. LAST 2,988,987

HIGH SPEED PRINTING MECHANISM Filed March l1, 1957 5 Sheets-Sheet 4 ffa/ I 3)/ June 20, 1961 J, LAST' 2,988,987

HIGH SPEED PRINTING MECHANISM Filed March l1, 1957 5 Sheets-Sheet 5 JAMES LAST /Nl/E/VTO/Q n/mWi/M A TTORA/E YS United States Patent "O 2988 987 HIGH SPEED riinsilNG James L'ast, St. Albans, England, assignor to Elliott Brothers (London) Limited, London, England, a British This invention relates to improvements in high speed printing mechanism. The development of electronic computors has made important the provision of printing mechanism capable of operating at speeds such that advantage can be taken of the very high speed of operation of such computors.

Accordingly, it is an. object of the invention to provide a mechanism capable of printing during each operating cycle a character, selected by the computor, in such a way that the operating cycle takes only a short time.

With'the foregoing object in view the present invention provides `a high speed printing mechanism for the purpose referred to, which comprises a continuously rotating type means, at least one hammer mounted for movement towards and away from the type means, means for accelerating said hammer towards the type means and disengageable from said hammer at the end of its driven stroke during which -said accelerating means proceeds to its'position of rest which is out of the path of movement of said hammer, means for imparting velocity to said accelerating member at a selected instant in the cycle of rotation of the type means and means for retaining s-aid accelerating member disengaged from the hammer or each hammer when not required to accelerate the associated hammer.

Generally more than one character must be printed in a Kline and' accordingly a plurality of printing units would be assembled in `close lateral juxtaposition in order that, during each operating cycle, a line of selected characters may be printed at a spacing of the same order as that commonly given by a typewriter.

By way of example, the accompanying d-iagrammatic drawings illustrate embodiments of the invention. In the drawings:

FIGURE l is a side elevation view, partly in section, of one form of printing unit,

FIGURE 2 is a View similar to FIGURE 1 of another form of printing unit,

, FIGURES 2a, 2b and 2c are diagrammatic views showing components of the unit according to FIGURE 2 in various positions during an operating cycle,

' FIGURE 3 is a view looking in the direction of arrow IIII in FIGURE 2, and

FIGURES 4, 4a, and 4b are fragmentary diagrammatic views of a modified form of printing unit, showing components at various positions during an operating cycle.

The printing unit illustrated in FIGURE l comprises a continuously rotary type carrier consisting of an assembly of typewheels 1 each having characters on its periphery, the type wheels being coaxially mounted and keyed together on a common drive shaft 112.. Parallel to the type carrier is a notched rotary cam 2 which is rotated con- -tinuously and synchronously in relation to the type carrier, so 'that a notch 3 of said cam 2 passes a given point for every passage of a character past a corresponding point.

A. row of hammers 4, one for each typewheel, is provided, the head of each hammer being adapted to strike sheet material '5, such as a record card or web, placed between the hammers 4 and the type carrier. Hammer actuators 6 are provided which are retained, against the action of springs Z1, by selector latches 7, each acting on a step i8 on the associated actuator 6.

V-shaped lugs 9, one on each actuator 6, are adapted to bear on the notched rotary cam 2 to enter one of the cam notches 3 under the action of 4actuator spring 21 when the step 8 of that actuator 6 which is to be operated is released from its latch 7. 'Ihe action of the lever 6 is shown in greater detail in FIGS. 2a, 2b, 2c. FIG. 2a shows the lever in its unselected position. FIG. 2b shows the latch disengaged and the lug 9 engaged with a cam notch 3. The nose 10 of the lever 6 is shown clear of the hammer tail 11 and the trunnion 20 displaced downwardly from the step 20B, sliding for this purpose against the face 20C. FIG. 2C shows the lever 6 raised mainly by rotation of the cam 2, to bring its trunnion -again into contact with the step 20B and the lever nose 10 behind the hammer ltail 11. Further rotation of the cam 2 expels the lug 9 from the notch 3 of the cam 2 and swings the lever z6 about its trunnion 20 to resume the position shown in FIG. 2a with the nose 1t) thereof underneath and clear of the hammer 4, which is displaced lengthways in its printing stroke during this movement.

Thus the mounting of this actuator '-6, and all other actuators, is such that its continued movement disengages the actuator nose 10 from the hammer end 11 just before the hammer head reaches the typewheel 1, this movement leaving the hammer 4 free to rebound and also permitting the associated selector latch 7 to re-engage the corresponding actuator step 8.

Each latch 7 which serves to control a hammer actuator y6 is substantially V-shaped and is rotatably mounted on a pivot pin 23. The pivot pin 23 is positioned on a slotted mounting bar 24. Where, as will generally be the case, several latches 7 are used, they are operated selectively, preferably, as shown, by electromagnetic means comprising 'a plurality of electromagnets 13 each having an armature 14 provided with a catch piece 15, engageable with a rocker 16 which co-operates with the notched cam 2 and one of the selector latches 7. Each rocker 116 is c-arried by a pivot pin 2S in a slotted mounting bar 26. A spring 22 anchored between the rocker 16 and the associated latch 7 normally biases the rocker 16 into engagement with the cam 2 and the latch 7 towards its associated actuator 6.

The rotary cam 2 is common to all typewheels and thus bridges the span of the typewheel assembly. The cam 2 and the typewheel shaft 12 are both rotated by a train of toothed gears 27 from a suitable source of rotatorymotion, such as an electric motor 2:8. Each typewheel 1 may have associated with it a hammer 4 and its actuator 6, and a selector latch 7. Alternatively, the actuator, its selector latch and associated magnet may be duplicated, two actuators operating on the same hammer. The paired groups of components are operable out of phase to double the frequency of operation, the groups respectively con trolling alternate series of characters.

lA resilient buffer 17 for limiting the stroke of the hammer toward the type member is preferably provided as shown and this member 17 is adjustable in the direction of movement of the hammer 4 to suit various thicknesses of material printed on.

Each hammer '4 is of parallel straight-Side form and extends radially of the typewheel 1, in a pair of guide notches 18A in a frame bar 18, the hammer 4 being slidably mounted to advance its head 4A toward and retract it from the typewheel 1 and being lightly biased by a spring 19 to assist its rebound.

Each actuator 6 is in the form of a lever lying at an obtuse angle to the axis along which the hammer slides and having its pawl-like nose 10 adjacent to the tail end 11 of the hammer shank. This actuator lever has a trunnion 20, formed at about the middle of its length, on which it can both pivot and slide lengthwise. The spring 21 is connected at one end to the end of the actu- 3 i ator lever `6, remote from its pawl-like nose 10, and is anchored by its other end to frame bar 18 in such a sense as to pull the actuator -lever 6 up towards the hammer 4 and also to swing the upper part thereof, betweenthe trunnion 20 and the hammer 4, towards the rotary cam 2.

When the magnet catch piece l5 is withdrawn from the rocker 16 and the nose 16h drops into a notch 3 of the cam 2, the latch 7 is disengaged from the step 8 on the actuator `6 by the lower end of the rocker 16. In this arrangement the one cam 2 having notches 3 all around its periphery is used to control both the actuator 6 and the rocker 16. The movement of the rocker 16 is due to the spring 22, the proportions of the members 1'6 and 7 being such that ya bias in the required direction is provided.

FIGURES 2 and 3 of the drawings illustrate another construction of the printing unit which differs slightly from that illustrated in FIGURE l. In this construction the substantially V-shaped selector latches 7 of FIGURE 1 are replaced by substantially straight latches 7A each pivoted intermediately of its length on a pin 23A engaged in a slotted mounting bar 24A. The associated rocker 16A, supported by pin 25A in a slotted mounting block 26A is, in this arrangement, disposed below its latch 7A and is rocked by engagement with the notches 29 of a separate rotary cam 30 instead of by cam 2 as in the FIGURE l construction; cam 30 derives its motion from gearing 27 driven by an electric motor as in FIGURE l. Because of the different disposition of the latches 7A and rockers 16A it is more convenient to dispose the operating electromagnets 13A at right angles to the position shown in FIGURE l, so that the armatures 14A thereof are `approximately vertical. The armature catch pieces 15A coact with rockers 16A in substantially the same manner as in the arrangement of FIGURE l.

In some cases a pivoted hammer, instead of a sliding hammer, may be employed.

FIGURE 4 illustrates an alternative form of hammer 4B and an actuator 6A for use therewith. In this case the actuator 6A has a iixed pivot 20A and on being released from its latch (not shown) the nose 10A thereof displaces the tail of the hammer 4B transversely of the length of said hammer, which by reason of tension spring 19A, has a degree of spring loaded transverse freedom in the necessary sense, in addition to the bias withdrawing said hammer from the type wheel 1, the spring loading of the actuator 6A being adequate to cause such displacement of the hammer 4B. In FIG. 4a the lug 9A is shown entering a notch 3 and its nose 10A just escaping from the tail of the hammer 4B, the hammer being tilted against the downward component of the pull of the spring 19A, and in Fig. 4b the nose 10A is shown clear of the hammer tail and behind it, the lug 9A being in the notch 3 to full depth and the hammer 4B again in the position shown in Fig. 4. On the expulsion of the `lug 9A from the notch 3, due to rotation of the cam 2, the nose 10A swings to resume the position shown in FIG. 4, displacing the hammer 4B lengthwise towards the typewheel 1 in doing so. The hammer rebound from the typewheel is helped by the other, horizontal, component of the spring 19A.

In applying the above described mechanisms to the operation of line printing a number of units, each mechanism comprising a typewheel, a hammer, an actuator, a latch and an electromagnet, is assembled at column pitch in a suitable frame as shown in FIGURE 3. In FIGURE 3 parts of some components are broken away for clearness. The common shaft l2 of a common elongated typewheel is geared to the rotary cam 2 which extends across all column units. The cam conveniently has longitudinal grooves, the walls of which are at right angles constituting cam notches 3, the trailing side of each groove being about twice as steep as the leading side thereof.

In the construction shown in FIGURES 2 and 3 the type wheels each have 50 characters and 10 blank places making 60 spaces in all. Also the cams 2 and 30 each have fifty notches and a blank portion of the periphery occupying the space of 10 notches making 60 spaces in all. During the passage of the 10 blank spaces past the printing line the paper may be fed and the blank portions of the cams ensure that no hammers can be actuated during this period.

I claim:

l. A high speed printing unit for the purpose referred to, comprising a frame; a typewheel mounted thereon; means for continuously rotating said typewheel; a hammer slidable in said frame and having a head adjacent to the typewheel, a shank arranged substantially radially thereto and a tail remote therefrom; a spring acting to withdraw said hammer radially from the typewheel, a rigid lever of the second order rockable on said frame and having a nose, a lug, a fulcrum and a tail, said lever having a degree of endways freedom and making an obtuse angle with the shank of the hammer, a circular cam having notches in its circumference, means for continuously rotating said cam about an axis parallel to that of the typewheel, a spring acting to swing the lever about its fulcrum in a plane normal to the axis of the typewheel to engage its lug with a notch in the cam and to bring its nose past the tail of the hammer, and a latch engageable with the tail of the lever, means for operating said latch at selected intervals of time to prevent such engagement but operable to release the lever for engagement with the cam and the hammer tail to effect the printing of a selected character presented by the typewheel.

2. A high speed printing unit for the purpose referred to, comprising a typewheel; means for continuously rotating said typewheel; a hammer support fixed adjacent said typewheel and having a downwardly facing surface constituting a rst fulcrum abutment and beneath it and approximately at right angles thereto another surface constituting a second fulcrum abutment; a hammer having a head disposed opposite the periphery of said typewheel, a shank carried by said support for sliding substantially radially to said typewheel and a tail remote from said typewheel; spring means acting between said support bar and said hammer to withdraw said hammer radially from said typewheel; a rigid actuator comprising a rockable lever of the second order having a nose for cooperating with said hammer tail, a fulcrum upon which said lever is rockable against said first fulcrum abutment on said support, a tail remote from said nose and a lug intermediately of said nose and said fulcrum, said actuator lever making an obtuse angle with said hammer shank, and having freedom for lengthwise displacement to move its fulcrum between said rst and second fulcrum abutments; a circular cam having notches in its peripheral surface and rotatable about an axis parallel to said typewheel; means for rotating said cam synchronously with said typewheel; a spring acting on said lever to swing it in a plane normal to the axis of said typewheel to engage its lug with a notch in said cam as said lever fulcrum moves between said fulcrum abutments and thus moves said lever nose into position behind said hammer tail; a latch rockable upon a pivot parallel to said first fulcrum abutment and acting on said lever tail normally to prevent engagement of said lug with said cam notch but operable to release said lever for engagement with said cam to propel said hammer tail to elfect endwise displacement of said hammer for cooperating with said typewheel for performing a printing operation, and means for imparting lever-release movement to said latch at selected intervals of time.

3. A high speed printing unit for the purpose referred to, comprising a typewheel; means for continuously rotating said typewheel; a hammer support fixed adjacent said typewheel; a hammer slidable in said support and having a head disposed opposite the periphery of said typewheel, a shank supported substantially radially to said typewheel and a tail remote from said typewheel; a spring acting to withdraw said hammer radially from said typewheel; a rigid actuator comprising a rockable lever of the second order having a nose for cooperating with said hammer tail, a fulcrum upon which said lever is rockable on said support, a tail remote from the lever nose and a lug intermediately of said nose and said fulcrum, said actuator lever making an obtuse angle with said hammer shank; a circular cam having notches in its peripheral surface and rotatable about an axis parallel to said typewheel; means for rotating said cam synchronously with said typewheel; a spring acting on said lever to swing it upon its fulcrum in a plane normal to the axis of said typewheel to engage its lug with a notch in said cam and to move its nose into position behind said hammer tail; a latch swingable upon a pivot parallel to said lever fulcrum and acting on said lever tail normally to prevent engagement of said lug with said cam notch; an electromagnet having a movable armature; a rocker interposed between said latch and said armature, means for imparting movement to said rocker at selected intervals of time, coordinated movement of said armature towardsaid electromagnet when energised and of said rocker imparting swinging movement to said latch to release said lever for engagement with said cam, whereby said lever is impelled to strike said hammer tail to impart a printing movement to said hammer.

4. A printing unit as claimed in claim 3, wherein said means for imparting periodic movement to said rocker is the said notched cam, as employed to move the hammer actuating lever.

5. A printing unit as claimed in claim 3, wherein said means for imparting periodic movement to said rocker is a second notched cam rotating synchronously with the cam which operates said hammer actuating lever.

6. A high speed printing unit for the purposes referred to, comprising a frame; a typewheel journalled for rotation on said frame; typewheel rotating means; a hammer movably Supported on said frame in opposition to said typewheel said hammer having a tail; spring means biasing said hammer away from said typewheel; a hammeractuator lever rockable on the frame about a pivot intermediately of the length of the lever said lever having one end normally situated adjacent the tail of said hammer, a V-shaped lug projecting from the lever between said one end and said pivot; a notched circular cam journalled in said frame for rotation about an axis parallel to the pivotal axis of the lever having notches adapted to be engaged by said lug; means for rotating said cam synchronously with said typewheel; second spring means biasing said lever and said lug toward said notched cam and to dispose said one lever end behind said hammer tail; a latch rockable on said frame and cooperating with the other end of said lever to prevent movement of the lever by said second spring means, and means for rocking said latch at selected intervals of time to release said lever to engage said lug with a notch of said cam whereon rotation of the cam expels the lug from the notch and swings the lever the said one end of which impels the hammer towards the typewheel.

References Cited in the le of this patent UNITED STATES PATENTS 2,013,533 Buhler Sept. 3, 1935 2,030,427 Buhler Feb. 11, 1936 2,066,784 Lake Jan. 5, 1937 2,227,143 Knutsen Dec. 31, 1940 2,566,944 Last Sept. 4, 1951 2,766,686 Fomenlro Oct. 16, 1956 2,792,779 Toeppen May 21, 1957

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