US2072878A - Typewriting machine - Google Patents

Description

March 9, 1937. W, F HELMOND 2,072,878

TYPEWRITING MACHINE Filed Feb. 23, 1935 5 Sheets-Sheet l BY my z.

' ATTORN v March .9, 1937. w. F. HELMOND 2,072,878

TYPEWR'ITING MACHINE Filed Feb. 25, 1935 5 sheets-sheet 2 l March 9, 1931. W. F. HELMOND 2,072,878

TYPEWRIT'ING MACHINE Filed Feb. 23, 1955 5 Sheets-Sheet 3` NVENTOR:

March 9, i937, w. F. HELMOND TYPEWRITING MACHINE Filed Feb. 25, 1955" 5 Sheets-Sheet 4 wdr.

INVENTOR:

l BY ATTORN March 9, 1937. w. F. HELMOND TYPEWRITING MACHINE Filed Feb.l 25, 1955 INVENTOR:

ATT NEY.

Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE TYPEWRITING MACHINE Application February 23, 1935, Serial No. 7,679

10 Claims.

This invention relates to typewritery typeactions and will be herein explained with referlence to a system of pivoted front-strike type-bars normally cumbent in an arcuate array which curves upwardly from the middle towards the sides of the system, and an associate system of type-key-levers extending individually fore and aft of the machine and disposed in substantially horizontal array below the type-bars.

The horizontal array of key-levers is to be connected to the arcuate array of type-bars by a system of type-bar-accelerating connections, so that there will ybe ease of key-touch at the beginning of the key-lever stroke, hand-cushioning absorption of the momentum of the operators hand at the end of the key-lever-printing stroke, and sharp printing impact of the type for clear printing and manifolding.

To these primary ends, said connections include a system of upstanding sub-levers. From a common fulcrum-axis the sub-levers range, in varying degree, upwardly and inwardly for,` disposing their upper end-portions in conformity with the arcuate array of cumbent type-bars to which said upper end-portions are connected, the lower portions of the sub-levers being contiguous to their respective key-'levers for connection to the latter, at a zone which is between the key-lever fulcrums and keys.

Each sub-lever is connected, at a point between its fulcrum-end and upper type-bar-driving end, to its key-lever by a short link extending forwardly from the sub-lever to an opposite point provided upon the key-lever. The arrangement 3;, is such that, during the dip of the key-lever, said short link pulls upon the sub-lever in a direction which becomes increasingly inclined toward a line joining said sub-lever point and fulcrum. The sub-lever and type-bar accordingly start 40 slowly, to make the key-touch easy, at the beginning of the key-stroke, the sub-lever and typebar speed continuously increasing as the keystroke progresses at uniform speed, there being,

correspondingly, continuously increasing resistance at the key throughout said stroke, thereby 55 type-bar-driving ends of the sub-levers, it being understood that the throws of the several links are to be substantially alike.

According to the invention, there is taken a novel link-pivot locus, with reference to which said links are established at their graded elevations, an'd the use of such novel locus affords important advantages.

To this end, a common key-lever fulcrum-axis and a locus for the points at which the links are pivoted to the sub-levers are relatively disposed so as to conduce to equi-distance of said linkpivotv points from said key-lever fulcrum-axis. For exactequidistance, said locus may be in the form of a circular arc whose center is said keylever fulcrum-axis. The radius of such curved locus may be such that a straight line passing through the highest and lowest pivot-link points on the sub-levers would be directed toward the sub-lever fulcrum-axis.

A further feature of the invention resides in applying such a locus to a machine in which the common key-lever fulcrum-axis is in the conventional location-near the base of the machine, as, for example, in the standard Underwood typewriter. The common sub-lever fulcrum may also be near said machine-base. In such case, it is feasible to provide the novel locus for the substantially higher link-pivot points on the keylevers by pitching said locus to slant rearwardly.

The links extend forwardly from the novel locus for pivotal connection to companion points on the key-levers. The links may be uniform in length throughout the type-action system; or, as will hereinafter appear, they need vary but slightly in length, to thereby provide for uniform depths of key-strokes where the lengths of the key-levers, from fulcrum to key, vary, as in a machine having a four-row keyboard from which the key-levers extend to the common fulcrumaxis, there being in such machine only four gradations of link-lengths.

Since, by use/of the novel locus, the link-pivot points, on the/sub-levers, are equidistant from the mean or common key-lever fulcrum-axis, and the forwardly-extending links are substantially uniform in length, it follows that the lengths of the lines from the key-lever fulcrums to the linkpivot points on the key-levers may be substantially uniform throughout the system, it being furthermore arranged that the angular relations of said links to said lines be substantially uniform throughout the system with reference to the normal positions of the parts.

Thus, by having said lines, which constitute the link-actuating lever-arms of the key-levers,

j may be made substantially uniform for all keysf.

substantially uniformV throughout the system, and at the same time having said angular relations to said lines substantially uniform, it will be found that the reactions upon the type-bars, by means of the links and graded sub-levers, may be made substantially uniform throughout the system, to the end that the keys may have uniform ease of key-touch throughout the keyboard at the beginningof any key-stroke.

It will also be found, by use of the novel locus, that the nal inclination of any link to the linkarm of the sub-lever, at the end of the key-stroke,

throughout the system, and that thereby, and also by reason of the aforesaid link-actuating lever-arms of the key-levers being substantially uniform, the reaction upon the type-bars by means of the sub-levers and links at the instant of high-speed-printing impact may be substantially uniform throughout the system. It will further be found, with reference to any intermediate phase of any key-stroke, that the ratio of type-bar speed to key speed will be substantially the same for all keys, and that consequently, irrespective of whether a type-bar at the middle or at either side of the system is operated, the corresponding keys will start the type-trains with uniform ease of initial key-touch, and there will be uniformity in the continuous increase of the speed of any type-bar, and consequent uniform momentum-absorbing hand-cushioning at the keys, at the instants of printing impacts.

The laforementioned pitching of the locus for the link-pivots does not rnilitate against the use of uniform means such as uniform pull-rods for connecting the sub-levers and type-bars. The use of such pull-rods which extend rearwardly from the sub-levers to the type-bars makes it feasible to dispose the system of sub-levers, the novel link-pivot locus and the links well forward of the type-bar system, and therefore well forward from the key-lever fulcrums, to thereby gain the advantage of working with an adequately extended stroke at the link-pivot on the key-lever, and other advantages. l

The invention also provides improvements pertaining to a system of retracting springs associated with the novel type-actions. There arefernployed a set of key-lever springs, and a set of auxiliary springs to aid the key-lever springs as when the purchase of a key-lever upon the sublever at the beginning of its return stroke is at a minimum, due to the maximumv inclination at that time of the connecting link. The auxiliary springs are therefore arranged to act directly upon the sub-levers and extend from a common anchor-member. The key-lever springs extend from a separate, common anchor-member, and novelwmeans are provided whereby said anchormembers may be jointly or individually adjusted to effect joint or individual adjustment of the tension effects of the two sets of springs, the arrangement-furthermore being such that individual adjustment of the several key-lever springs may be effected.

Improved devices are also provided whereby the connection or disconnection of the sub-levers, links and key-levers, as in servicing theumachine, is facilitated.

Other yfeatures and advantages will hereinafter appear.

In the accompany drawings,

Figure lI is a side-elevation View of the novelV type-action and spring-system, and parts of the typewriter related thereto, some of the members being shown in section.

Figure 2 is an enlarged fragmentary plan view, showing details of the arrangement provided to facilitate connection and disconnection of the sub-lever, key-lever and connecting link.

Figure 3 is a perspective View, showing features of the type-action and spring-system in detail, some of the parts being sectioned and broken away for clearness.

Figure 4 is a frontlview of the sub-levers to illustrate the grading of the upper ends of the latter for connection to the type-bars.

Figure 5 is a side-elevation view, showing a middle type-action of the system operated to printing-position.

Figure 6 is a fragmentary elevation view to illustrate tilting of the type-bar segment to provide clearance between the array of type-bars and parts thereunder.

Figures '7, 8, 9 and 10 are straight-line diagrams of the type-actions, Figures 7 and 8 showing respectively normal and operated positions of typeaotions corresponding to the rearmost bank or row of type-keys, while Figures 9 and 1.0 show normal and operated positions of the type-actions corresponding to the foremost bank of type-keys'. Figure 11 is a view illustrative of four gradations of the links connecting the sub-levers and keylevers.

Key-levers I5 having type-keys I6, constituting the usual keyboard, extend rearwardly from the latter to a common fulcrum-rod Il retained in a cross-bar I8, supported by the partly-shown main frame I9 of the machine. Slots 20 of said crossbar space the rear ends of the key-levers transversely of the machine. A comb-plate 2l, supported bythe machine-framework, similarly spaces the key-levers at their forward portions,

and may support a cushioning stop 22 Awhich the key-levers abut, Figure 1, to determine their normal positions.

By means of said key-levers, and novel connections which will presently be described, typebars 23, normally cumbent in arcuate array, as indicated in Figures 1 and 3, are selectively actuated to bring their types 24 to a common printingpoint traversed by a platen 25 mounted in a carriage (not shown).

A type-bar segment 21, having an arcuate fulcrum-rod 28, about which the type-bars 23 swing, and also having radial type-bar-spacing slots 29, determines the arcuate type-bar array which curves upwardly from the middle to the sides of the system, and in which array the cumbent type-bars abut an arcuate rest 30. A type-guide 3| upon the segment 21 co-operates in known manner with a nose 32 of any type-bar to gage the printing-point.

'I'he key-levers I5 have their fulcrum-rod I1, at the rear of the machine, somewhat above the base of the machine, as indicated in Figure 1, and are disposed in horizontal array acrossthe machine.

In the means for connecting the horizontallyarrayed key-levers to the arcuately-arrayed typebars, there is included a system of graded sublevers 34 upstanding from a common fulcrumrod 35, disposed somewhat above the base of the machine, Figure 1, and horizontally retained in a cross-bar 36, which may be supported by the main frame I9. Said cross-bar has slots 31, whereby the lower portions of the sub-levers are levers I5, the latter being formed with uniform ating arms 53a of the type-bars by pull-rods li,

the array of sub-levers 3A being disposed forwardly of the type-bar fulcrum-rod 2B. For uniformity in the lengths of said pull-rods 4d, said operating points 43 of the type-bars may be uniformly disposed relatively to the fulcrum-rod 26, and the sub-levers may be formed so that their upper type-bar-driving points t2 are uniformly disposed relatively to said type-bar-operating arms, as indicated in Figure 1.

In order that the key-touch may be light at the beginning of the key-stroke, and that the speed of the sub-lever 313 and type-bar 23 continuously increases from a slow starting speed while the key-stroke progresses at even speed, each keylever I5 is connected to the corresponding sublever 3d by .a link 135. The arrangement is such that said link l5 becomes increasingly inclined to the sub-lever 33, and thereby increases the ratio of movement of the latter to the key-lever movement, as the key-stroke progresses, as may be understood from a comparison of Figures 1 and 5, which respectively show a type-action in normal position and operated to printing-position.

For such action, each link l5 is pivotally connected to its sub-lever 36 at a point d6, intermediate of the type-bar-driving point d2 and the fulcrum-rod 35, and the link extends forwardly from the sub-lever, as in Figure 1, for pivotal connection to a companion point il on the corresponding key-lever I5. The lower portions of the sub-levers, which include the link-pivots d5, may be disposed in conformity with the array of key-levers. For conforming to the narrower, arcuate array of the points i3 on the type-bars, the upper end-portions of the sub-levers, which include the type-bar-driving points d2, are made to converge, by bending them inwardly, as indicated at 38, Figure 3, it being understood that, from the middle of the system, where the sublevers 3Q are practically straight, the heights of the bends at d8 and the inward inclinations of the upper sub-lever portions i9 may be graded as indicated in Figure 4.

The links i5 -work at graded elevations or distances above the sub-lever fulcrum-rod 35, in order that substantially uniform throws of said links as effected by the key-lever strokes may produce substantially uniform strokes at the type-bar-driving points 42 of the graded sublevers 34. Thus, the link-pivot points 46 on the several graded sub-levers are at graded distances or elevations above the sub-lever fulcrum-rod 35, and, conformingly, the companion link-pivot points lil on the several key-levers I5 are disposed at graded elevations by means of pointprojecting arms 5I of graded lengths formed on the several key-levers at the corners of the keylever portions 39 and 40.

A locus 52 for the link-pivot points 46 on the sub-levers 3B of the several type-actions viewed as in Figure 1 is disposed relatively to the common key-lever fulcrum-axis II, so as to conduce to equidistance of said points 46 from said axis II. To this end, where said key-lever fulcrum-r` axis I1 and the sub-lever fulcrum-axis 35 are near the base of the machine, as indicated, and said link-pivot points 46 are substantially higher, said locus may be pitched or slanted rearwardly.

For exact equidistance of the sub-lever-linkpivot points 46 from the key-lever fulcrum-axis I'I, said locus 52 may be in the form of a circular arc, whose center is at the key-lever fulcrum-axis I1, and whose radius R, Figures '7 and 9, is preferably such that a straight line through the highest and lowest sub-lever-link-pivot points 46 on saidA circular locus is directed toward the sub-lever fulcrum-axis 35.

The links 65 may be uniform in length, or, as will presently be explained, they may vary slightly in accordance with the rows of keys I6 of the keyboard. Thus the lengths of the linklever arms from fulcrum I1 to link-pivot point i1 on the key-levers will be practically uniform throughout the system, it being noted that, in conjunction with this uniformity of said linklever arms II, 4H, the inclination of the links 45 thereto may also be substantially uniform throughout the system. It will be found also that the inclinations of the links d5 to the arms 35, d6 of the sub-levers will be substantially uniform at the ends ofthe key-strokes. In the straight-line diagrams at Figures 7 and 9, the uniform link-inclination to the link-lever arms l1, d1, in the normal position of the parts, is taken at say fifteen degrees, and, as indicated in the diagrams at Figures 8 and 10, the inclination of said link to the sub-lever arm 35, 46, at the end of the key-stroke will be substantially uniform at say twenty-five degrees.

Since the key-lever length from the common fulcrum I'I to key I6 is different for each row of keys, it will be seen that, for uniform depth of key-stroke, the angular displacement of the keylevers for the several key-rows will be different.

.Taking the key-levers for the rearmost and foremost rows for comparison and their respective greater and less angular displacement for equal depths of key-stroke, it will be found that the Condition of uniformity of the initial and final inclinations of the links i5 may be preserved by making the links i5 for the foremost row of key-levers somewhat shorter than the links d5 for the rearmost row.

The diagrams at Figures 7 and 8 represent, respectively, the normal and operated positions of the type-actions for the rearmost row of keys; and the diagrams at Figures 9 and 10 represent, respectively, the normal and operated positions of the type-actions for the foremost row of keys, the keys in said rows having the same depths of key-strokes.

Said diagrams at Figures 7-10 indicate the desired uniformity of initial link inclination of say the given fifteen degrees, and also indicate the uniformity of final link inclination of say the given twenty-five degrees, said uniformity being attained by the described difference in link lengths. It will be understood that the lengths of the links 45 for the key-actions for the intermediate or illustrated second and third rows of keys will be intermediately graded to the end that the initial and nal link inclinations be uniform with those of the foremost and rearmost rows of keys. Thus, for a fourrow keyboard there will be four gradations of link lengths, as indicated in Figure 11.

Each of the diagrams at Figures 7-10 represents a full row of type-actions by the showing of lines for a middle type-action and for a typevdotted lines 56, Figure 1.

action at the end of the row, it being deemed unnecessary to indicate the intermediate type-actions, since it is to be understood that the gradations of the link-pivot points 46, 41, by means of the curved locus 52, are between the two eX- tremes illustrated in each diagram. It will also be understood that the initial and nal link inclinations are uniform for the type-actions in each key-row, as well as with respect to the typeactions for the several key-rows. It may also be noted that said gradations of the link-pivot points 46, 41, by means of the locus 52, are arranged to effect uniform throws, represented in said diagrams by the dotted lines 54, of the type-bar-driving points 42 of the sub-levers 34.

It will be seen that, by use of a link-pivot locus, such4 as 52, there are gained two important advantages, namely, the link-actuating 1ever-arm I1, 41 of the key-levers may be substantially uniform throughout the system, and

the aforementioned initial and final link inclinations may also eac-h be substantially uniform throughout the system. It will be found to result from said conditions that each type-action has the same characteristic as to touch and printing and lmanifolding effect.

In other words, links such as 45 are used to the best advantage in that they are herein so arranged relatively to sub-levers such as 34 and key-levers such as I5, as to conduce to uniformity throughout the system, in the initial ease of keytouch due to the slow starting of the type-action, and to uniformity in the continuous increase of the type-bar speed as the key-stroke progresses evenly, said uniformity of the continuous increase intype-bar (and sub-lever) speed conducing to uniformity in the increased resistance at the key, and thereby conducing to uniformity in cushioning the operators hand at the instant of printing impact of the types. The uniformity of continuous increase of type-bar speed also has the effect of conducing toI uniformly sharp impact of the type-bar at the instant of printing, to make the printing uniformly clear and conduce to uniform good manifolding by any type-action irrespective of whether it is at the middle or the side of the system.

In Figure 1 the dotted lines 55 represent equal increments of the key-stroke. Said equal keystroke increments produce, by means of the accompanying increase in the inclination of the link 45, continuously increasing increments in the type-bar displacement as represented by the Thus, the type-bar starts slowly with the first increment of the keystroke and following equal increments of the keystroke each produce an increased type-bar displacement as represented by the increasing spaces between the dotted lines 56, each of which corresponds to a line 55 at the key I6 as indicated by the numerals 0 to 9 at said dotted lines 55, 56.

The final increment 8, 9 at the lines 56, representing the type-bar movement, indicates that the type-bar speed will have been accelerated to a maximum at the instant of printing, so that there will be sharp printing impact of the type conducive to clear printing and' manifolding.

It is to be noted that the proportions of typebar displacement to equal increments of the keystroke, as' depicted in Figure 1, obtain substantialy uniformly throughout -the system by reason of the herein-described arrangement of the keylevers I5, the sub-levers 34 and the links 45,

g5 thereby conducing to the described uniformity in key-touch and printing-characteristics of the type-actions throughout the system.

'I'he novel spring-system for they type-actions will now be described.

For each key-lever I5 there is an individual restoring spring 58, which by means of notches 59 upon the key-lever may engage the latter at different distances from the key-lever fulcrumrod I 1, to thereby regulate the effect of the spring upon'the key-lever. The springs for the several key-levers are connected to a common anchorrod 68, supported at its ends by arms 6I and at an intermediate point by an arm v62, said arms 6I, 62 extending forwardly from and being fastened to a cross-rod 63, removably journaled at its ends in open sockets 64 formed in the main frame I9, as indicated in Figure 3. An arm 65 extending from the main frame I9 is arranged as shown to support the cross-rod 63, at a point intermediate its ends to minimize defiection of said cross-rod 63 and anchor-rod 60 under the pull of the row of springs 58.

Extending rearwardly from and fastened to the cross-rod 63 is an arm 66 having notches 61, in one or another of which a link 68 pendent from said notched arm 66 is caught, said pendent link 68 being similarly caught at its lower end in one or another of notches formed by the threads of a screw 69, which projects forwardlly from the main frame I9 and co-operates with said pendent link 68 for adjustably securing the spring-anchor structure comprising the rods 60, 63. Said screw 69 may be guided for endwise adjustment in a bushing 10 and carries a thumb-nut 1I for effecting said adjustment micrometrically. For articulation with the notches 61 of arm 66 and of the screw 69, the pendent link 68 may have sharp-edged openings 12, as indicated in Figures 1 and 3.

By means of a flattened forward extension 14 slidably tting a guide-slot 15 in a cross-bar 16, supported at the sides of the main frame I9 to which it may be secured by screws 16a, the screw 69 is prevented from turning so that turning of the thumb-nut 1I is effective to move the screw 69 endwise in a forward or rearward direction. Said cross-bar 16 also co-operates to support the screw 69 against deection under. the pull of the pendent link 68. Such endwise movement of the screw 69 shifts the bottom of the link 68 forwardly or backwardly, and thereby causes turning of the spring-anchor frame in the sockets 64 to thereby raise or lower the anchor-rod'60 to vary the tension of all the key-lever springs 58. Thus, by turning said thumb-screw 1I one way or the other, the tension effect of the springs 58 upon all the key-levers is varied, while, for individual adjustment of the tension effect upon each keylever, the lower end of the corresponding spring gg may be adjusted along the key-lever notches Referring to Figure-5, which shows a typeaction in printing-position and about to commence its return stroke, it will be seen that the effect of the key-lever spring 58 is at a minimum for starting the return of the type-action, in so far as the purchase of the key-lever upon the sub-lever 34 is at a minimum due to the maximum inclination of the link 45. For reinforcing the effect of the key-lever springs 58 at the start of returning the type-action, there is provided a system of auxiliary springs 11, arranged to act directly upon the sub-levers 34. Each auxiliary spring 11 may accordingly be attached at one end lower the spring-anchor rod 60.

to a stud 46 which, as indicated in Figures 1, 3 and 5, also serves as the link-pivot 46 upon the sub-lever. The other ends of the set of auxiliary springs 11 may be attached to a' common anchorplate 19, which, for adjustment to vary the tension of all the auxiliary springs 11, may be connected to the screw 69, the flattened portion 14 of the latter having for this purpose a hooked end 80 engaging a companion slot 8| in said auxiliary spring-anchor plate 19.

It will be seen that a quick change or adjustment of the tension eiect .of the key-lever springs 58 may be made by pressing downward at the upper end 68al of the link 68 to free its lower end from the screw 59, and then tilting said link forward or backward to change the location of said lower link-end along the screw 69, to raise or In this way quick and say approximately correct adjustment of the tension eect of the key-lever springs 58 may be made first, and then the thumb-nut 1| may be turned to make a liner adjustment of the tension effect of the key-lever springs 58. It will also be seen that, by turning the thumbnut 1|, the tension effect of the key-lever springs 58 and the sub-lever auxiliary springs 11 may be adjusted` jointly, provided the link 68 remains in engagement with the screw 69. The sublever or auxiliary springs 11 may also be adjusted without changing the tension effect of the key-lever springs 58. In such case the thumb-nut 1| would be turned until the desired tension effect of the auxiliary springs 11 is obtained, the link |58 being manipulated either to restore the lower link-end, after the thumb-nut 1| is turned for the auxiliary spring adjustment, or to hold said lower link-end clear of the screw 69, while the thumb-nut 1| is turned to effect the auxiliary spring adjustment.

It will also be seen that movement of the lower end of the link 68 along the screw 69 will cause raising or lowering of the key-lever spring-anchor rod $9 to extents which will vary in accordance with the particular notch 61 of arm 66 which the link 68 depends from.

For facilitating connection and disconnection of the links 45, the sub-levers 34 and the keylevers i5, the studs. which constitute the linkpivot points 46 and 41 and which have the same reference numbers as said pivot-points, may be made Without enlarged heads, and, in lieu of said enlarged heads, said studs m/ay extend substantially beyond the outer side of the link, as indicated in Figure 2. Adjacentdy said outer link-side the link-pivot stud 46 may have a groove 82 into which an elongately loopedfnd 83of the auxiliary or sub-lever spring 11 is hooked to keep the link 45 in place. Thus, when y, e auxiliary spring-end sa is unhcoked from th/pivot-stud 4s, the 1mi: 45 may be readily disconnected from or reconnected to the sub-lever and key-lever to facilitate servicing of the machine. With the links 45 disconnectible and reconnectible as described removal and replacement of any key-lever l is facilitated, it being noted that to this end the key-lever reach 39, 40, 4|', from the keyboard to the key-lever fulcrum-rod |1 is arranged to pass under the array of sub-levers 34 and other parts. The vertical portions 40 of the key-lever reaches may present shoulders 84 engageable by a keylocking device not shown.

It will be noted that, by using the pull-rods 44 to connect the type-bars 23 and sub-levers 34, the latter are disposed well forward in the machine, so that, correspondingly, the links 45 are easily accessible for removal or replacement.

There is also gained by such forward disposal of the sub-levers adequate extent of stroke at the link-pivot point 41 on the key-levers.

The type-bar segment 21 may be guided for case-shifting movements eifected by suitable means represented by bell-cranks 85, in Figures 1 and 3, there being one of said bell-cranks at each side of the segment, and the bell-cranks being. connected to shift the segment parallelly. 'As indicated in Figure 3 there may be at each side of the segment 21, for guiding the latter, a raceway 86 on the machine-framework I9, a companion raceway 81 on the segment and an antifriction roller 88. When the type-bars -23 are shifted with their segment 21 down or up, the pull-rods 44 move idly about the points 42 on the sub-levers. The type-bar rest 30 shifts with the type-bar segment 21, a support 89 for said rest 39 being connected to the type-bar segment 21 by rods 89a.

Figure 6 shows a type-bar segment 21a tilted so that the array of type-bars 23 is correspondingly tilted to afford adequate clearance between the type-bar array and the sub-levers 34, as when the type-bar arr-ay is depressed to the lowercase position indicated by the dotted outline in Figure 6.

Each type-bar 23 may have near its fulcrum a heel 9U to actuate an arcuate universal bar 9|. Connected to said universal bar are side-arms 92 pivoted to a rock-frame 93, journaled at 94 in arms 95 extending rearwardly from the type-bar segment 21. Said rock-frame 93 co-operates with a tongue 96 of the universal-bar structure to support the latter for fore-and-aft movement, said tongue being slidably tted in the type-bar segment 21. Mechanism such, for example, as a letter-feeding escapement to be actuated by the universal bar 9| may be stationary with respect to the case-shiftable type-bar segment 21, and is diagrammatically indicated at 91, Figure 1. A link 98 may extend from the universal-bar structure on the type-bar segment and swings idly about the point 99 of said mechanism 91 at the case-shift movements of the type-bar segment.

Variations may be resorted to within the scope of the invention and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a system of-key-operated trains for actuating a set of typewriter type-bars; a series of type-key levers extending from a keyboard to a mean fulcrum-axis, a series of upstanding graded sub-levers connected to the type-bars, said sublevers arrayed transversely of the machine at a Zone between the keyboard and the key-lever fulcrum-axis, and a series of links connecting the key-levers and sub-levers at graded elevations, said links being arranged 'so that each link becomes inceasingly inclined to its sub-lever as the key-lever printing-stroke progresses', to thereby accelerate said sub-lever and its type-bar, the accelerating links being further arranged with their pivotal connecting points, to the sub-levers and to the key-levers, respectively, at substantially equal distances from said mean key-lever fulcrum-axis, thereby to conduce to uniformity in the acceleration of the several sub-levers and type-bars.

2. In a system of key-operated trains for actu-- levers arrayed transversely of the machine at a zone between the keyboard and the key-lever fulcrum-axis, and a series of links connecting the key-levers and sub-levers at graded elevations, said links being arranged sov that each link becomes increasingly inclined to its sub-lever as the key-lever printing-stroke progresses, to thereby accelerate said sub-lever and its type-bar, the accelerating links being further arranged with their pivotal connecting points, to the sub-levers and to the key-levers respectively, at substantially equal distances from said mean key-lever fulcrum-axis, and arranged also so that the initial and nal inclinations of each link to its sublever are substantially uniform with reference to the several sub-levers, thereby to conduce to uniformity in the acceleration of the several sublevers and type-bars.

3. In a system of key-operated trains for actuating a set of typewriter type-bars; a series of type-key levers extending from a keyboard to a mean fulcrum-axis, a series of upstanding graded sub-levers connected to the type-bars, said sublevers arrayed transversely of the machine at a zone between the keyboard and the key-lever fulcrum-axis, and a series of links connecting the key-levers and sub-levers at graded elevations, said links being arranged so that each link becomes increasingly inclined to its sub-lever as the key-lever printing-stroke progresses, to thereby accelerate said sub-lever and its type-bar, said accelerating links at their graded elevations, and in the normal positions of said trains, having their points of pivotal connection to the sub-levers on a curved locus which is concentric with the mean key-lever fulcrum-axis, thereby to conduce to uniformity in the acceleration of the several sublevers and type-bars. l'

4. Inra system of key-operated trains for actu ating a set of typewriter type-bars; a series of type-key levers extending from a keyboard to a mean fulcrum-axis, a seriesof upstanding graded sub-levers connected to the type-bars, said sublevers arrayed transversely of the machine at a zone between the keyboard and the key-lever fulcrum-axis, and a series of links connecting the key-levers and sub-levers at graded elevations, said links being arranged so that each link becomes increasingly inclined to its sub-lever as the key-lever printing-stroke progresses, to thereby accelerate said sub-lever and its type-bar, said accelerating links at their graded elevations, and

in the normal positions of said trains, havingv ating a set of typewriter type-bars; a series of type-key levers extending from a keyboard to a mean fulcrum-axis, a series of upstanding graded sub-levers connected to the type-bars, said sub- ,levers arrayed transversely of the machine at a zone between the keyboard and the key-lever fulcrum-axis, and a series of links connecting the key-levers and sub-levers at graded eleva-tions, said links being arranged so that each link becomes increasingly inclined to its sub-lever as the key-lever printing-stroke progresses, to thereby accelerate said sub-leverand its type-bar, said accelerating links at their graded elevations, and

in the normal positions of said trains, having their points of pivotal connection to the sub-levers on a curved locus which is concentric with the mean key-lever fulcrum-axis, thereby to conduce to uniformity in the acceleration of the several sublevers and type-bars, said key-levers being of different lengths to form the key-rows of the keyboard, and the lengths of said links being graded in correspondence with the several key-rows, whereby the operation of said sub-levers and type-bars is eiected by key-strokes which are substantially uniform in depth throughout the keyboard.

6. In a system of key-operated trains for actuating a set of typewriter type-bars; a series of type-key levers extending from a keyboard to a mean fulcrum-axis, a series ofl upstanding graded sub-levers connected to the type-bars, said sub-levers arrayed transversly of the machineat a zone between the keyboard and the key-lever fulcrum-axis, and a series of links connecting the key-levers and sub-levers at graded elevations, said links being arranged so that each link becomes increasingly inclined to its sublever as the key-lever printing-stroke progresses, to thereby accelerate said sub-lever and its typebar, said accelerating links at their graded elevations, and in the normal positions of said trains,

having their points of pivotal connection to the sub-levers on Ia curved locus which is concentric with the mean key-lever fulcrum-axis, and said accelerating links, in said normal positions of the trains, extending severally at substantially uniform angles from said locus, thereby to conduce to uniformity in the acceleration of the several sub-levers and type-bars, said key-levers being of diierent lengths to form the key-rows of the keyboard, and the lengths of said links being graded in correspondence with the several keyrows', whereby the operation of said sub-levers and type-bars is effected by key-strokes which are susbtantially uniform in depth throughout the keyboard.

7. In a system of key-operated trains for actuating a set of typewriter type-bars, the typewriter having a box-like frame; a series of typekey levers extending rearwardly from a keyboard at the front of said frame to a mean fulcrum-axis disposed near the rear bottom corner of said frame, a series of sub-levers upstanding in graded extents from their fulcrums and connected by means of their upper ends to the typebars, said gub-levers being arrayed transversely of the machine at a zone between the keyboard and the key-lever fulcrum-axis, and a series of links connecting the key-levers and sub-levers at graded elevations in accordance with the diierent extents of the sub-levers, said links being arranged so that each link becomes increasingly inclined to its sub-lever as the key-lever printing progresses, to thereby continuously accelerate said sub-lever and its type-bar, said accelerating links, at their graded elevations and in the normal positions of said trains, having their points of pivotal connection to the Sub-levers on a locus which is inclined upwardly and rearwardly to conduce to equidistance of said points from said mean key-lever fulcrum-axis, thereby to conduce to uniformity in the acceleration of the several sub-levers and type-bars.

8. In a front-strike typewriting-machine typeaction system, a set of type-key levers disposed in horizontal array across the machine, and extending individually fore and aft of the machine and from a mean fulcrum-axis, an arcuate array lof-"normally cumbent pivoted type-bars g `'above the'key-levers, a system of sub-levers up- Am Y standing in graded lengths from their fulcrums andfdisposed at a zone between said key-lever fulcrum-axis and the keyboard, said sub-levers being.. connected at their upper ends to said k type-bars, and a system of. links connecting the uniform'strokes of the links. as eiected by the key-levers', eiect substantially uniform strokes of-the upper type-bar actuating ends of the suble'vers, the sub-levers and key-levers being relaf `tively arranged, so that the locus of the points of A link-connection on the sub-levers is such that vsaid points are substantially equidistant from: said mean key-lever fulcrurn-axis, thereby- -to conduce vto uniformity'of s'aidtype-bar accelera-` tion throughout thesystem. i

9, Ajsystem of front-strike type-actions including'v swingable type-bars cumbently arrayed around a fulcrum-axis curving upwardly to the left and right of the middle, a set of type-key levers below said type-bars and extending rearwardlyl from a keyboard to a mean fulcrum-axis, and a simple system of connections devised to enable said key-levers to actuate said type-bars uniformly as to key-touch, acceleration of the type-bar printing stroke, and printing impact, said system of connections including sub-levers of the third class upstanding from a transverse common fulcrum-axis, said sub-levers being connected at their upper ends to said type-bars, and being therefore graded as to the length of their type-bar-actuating arms,` and 'links severally connecting the key-levers and sub-'levers at elevations graded proportionately to said type-baractuating arms, said links being arranged so that each link becomes increasingly inclined to its sub-lever'as the key-lever printing stroke pro- -gresses for accelerating said sub-lever and its type-bar, said links, in the normal positions of the type-actions, having their graded points of pivotal connection to the sub-levers on such f locus as to be substantially equidistant *from the mean key-leVer-fulcrum axis,

l0. In a system of front-strike type-actions, swingable type-bars normally cumbent at the middle, sides and intermediate places of an arcuate array of the character described, key-levers below said type-bar array and extending rearwardly from a keyboard to a mean fulcrum-axis, sub-'levers having ulcrum-means between the key-lever-fulcrum axis and keyboard, said sublevers iembodying type-bar-actuating arms graded in diierent lengths in conformity with the arcuate type-bar array, said sub-levers also embodying operating arms defined by points graded, as

4to distance from the sub-lever-fulcrum means,

proportionately to the type-bar arms, and linkvrods, ealch connecting a sub-lever operating point v vto a companion point of the key-lever, each linkrodbeing arranged so as to become increasingly inclined to its sub-lever as the key-lever printing stroke progresses for continuously accelerating said sub-lever and type-bar, the graded A tion, whether at the middle, side or intermediate place of the type-action system, has substantially the same characteristics as to key-touch, keystroke, type-bar acceleration, and printing impact.

WILLIAM F. HELMOND.

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