US2681129A - Type action system for typewriting machines - Google Patents

Description

June 15, 1954 H. c. YAEGER TYPE ACTION SYSTEM FOR TYPEWRITING MACHINES 2 Sheets-Sheet 1 Filed Dec. 11, 1951 lNl ENTOR HARM QC. MEGER ATTORNEY H. c. YAEGER TYPE ACTION SYSTEM FOR TYPEWRITING MACHINES Filed Dec. 11, 1951 June 15, 1954 2 Sheets-Sheet 2 INVENTOR. HARRY C. VAEGER Patented June 15, 1954 Harry G. Yaeger, West Hartford, 001111., assignor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application December 11, 1951, Serial No. 260,960

6 Claims.

This invention relates to typewriters and the like and more particularly to type-action systems thereof having the type bars pivoted in an arouate array on a segment to strike at a common typing point, and wherein case shift is effected system with the direction or path of case shift.

Accordingly, a general object of the invention is to provide, in a segment-shift, hammer typebar kind of typewriter, an arrangement of the type-action system and a case-shift guiding 6 by shifting the type-bar segment. means coordinated therewith, which arrange- In type-action systems to which the invention ment aifords a substantial angular relation be pertains, each type bar is actuated by a straight tween the quiescent type bars and their underlink or pull rod extending forwardly beneath the lying pull links.

- type bar from its point of connection to an oper- 1: Another object is to provide a segment caseating arm of the type bar. In segment-shift shift arrangement coordinated with an improved typewriters the segment is usually shifted in a type-action system, the organization and ar plane that is tangential to the platen at the rangement of the elements of the latter having typing point. In order not to transmit any perthe advantage of accommodating an appreciably ceptible motion to the key levers nor change the inclined segment for purposes such as to secure a operating relation of the parts during case shifttyping point well above the level of the platen ing, these pull links are usually arranged subaxis, the related tilting of the type bars being stantially at right angles to said plane of shift. readily feasible without however necessitating Each pull link is connected at its forward end any major change in the arrangement of other to an actuating member, which in the Undertype-action elements, particularly the substanwood typewriter takes the form of a sub-lever, as tially horizontal disposition of the underlying pull exemplified in Helmond patent, No. 2,072,878, for links. manual typewriters, and in Yaeger patent, No. In prior segment-shift typewriters, the neces- 2,254,764, for power-operated typewriters. As Sity of shifting the S t dow w d to effect shown in said patents, the type-action pull links case shift presented a condition which, because assume substantially horizontal positions in acof the substantially parallel close relation of the cord with the substantially vertical plane of case q i n yp bars nd h r p links, m d i shift and are therefore at or very close to a, impracticable to provide the requisite dust shelf parallel relation with the horizontal type bars. on the segment, because of the lack of sp In typewriters wherein the segment shifts in a l r f h lin n ary to ommodate vertical plane, this is due mainly to the fact that bowed or arched type bars required to clear the the typing point is at a level with the platen axis, dust Shelf. and the plane of shift is required to be tangen- A further object, therefore, resides in the protial with the platen at said point. Should it be vision of a correlated type-action system and S edesired to have the typing point appreciably merit shift arrangement, by which adequat i above the level of the platen axis, it then becomes ing between the type bars and their straight necessary to correspondingly tilt the type-bar Operating links is had, 50 that the downwardly segment so that its plane of shift is tangential at ed typ bars, arched 50 a 110 lear a said raised typing point, the type bars at rest segment-carried dust shield, will not clash with being also correspondingly inclined. The reor obstruct proper operation of the type-acti0n sultant inclination of the type bar dissolves its lin sparallelrelation with the pull link, unless the Other objects will be in p t bv s and in position of the latter is also to be substantially part Particularly pointed out as the following changed. Thus, if it is necessary to discontinue scription of a P efe ed embodiment of the nthis substantially parallel relation between the Vention p ce type bar and its operating link, either to raise In e d wi the typing point appreciably above the level of Figure l is a sectional View taken on a medial the platen axis without changing the horizontal plane iore-and-aft of the typewriter embodying position of the pull link, or to afford an apprethe invention, and, showing a middle type action ciable angular space relation between these parts and another type action at the far side of the for reason such as to accommodate a type bar typeaction system, that is arched to clear a dust shield on the seg- Figure 2 is a plan view of the type-action ment, this disturbs the fundamental relation of system taken on a plane 22 of Figure 1, but the type-action elements and this in turn mateviewing only the half of the type-action system rially upsets the inter-relation of the type-action opposite that shown in Figure 1, and

Figure 3 is a front view of the type-action system taken on a line 3-3 of Figure 2.

Except for the relative arrangement of several of the series of type-action parts as hereinafter explained, the type-action system forming the illustrated embodiment of the invention conforms substantially to that described and claimed in the Helmond patent, No. 2,072,878. A brief description of the type-action system herein will therefore sumce. Referring to Figure 1 a series of key levers 5, the forward key-equipped portions of which are omitted, are each pivoted on a common fulcrum rod in a crossbar 6 of the typewriter. At a point intermediate its end, each key lever is connected by a link 1 to a sub lever 3. The sub-levers 3 are all pivoted on a common fulcrum rod retained in a crossbar it.

A series of type bars H are each pivoted in an arcuate array on a pivot rod [2 in the segment l3. Each type bar ii has an operating arm It extending rearwardly and downwardly from the pivot i2 and having a connection i5 to a pull link IS, the other end of which is connected at H to a corresponding one of the sub-levers 8.

In view of the arcuate arrangement of the type-bar pivots 42, the connections 15 to the links it also present a curved or arcuate formation, see Figure 3. The lower portion of each sublever B, where same is pivoted in the crossbar iii, is disposed vertically in the plane of the associated key lever 5. This makes the row of sub levers 8 appreciably wider, transversely of the typewriter, than the array of the type-bar-link connections 15. Therefore, the successive sublevers 8 are bent to offset their upper ends at gradually increasing extents, ranging from the center type action outward, so that said ends at which the links id are connected are close to the plane of the corresponding operating arms i of the type bars. To assure a uniform length for the links I6, and to attain certain operating advantages incidental to case shifting, the upper end portions of the sub-levers B forming the link connections I? present an arcuate array conforming substantially to that of the link connections 15 and circumjacent thereto, as shown in Figure 3, and each of said end portions is disposed in a plane radiating from the typing point as later described. As described in detail in said Helmond patent, the points of connection of the links 1 to the sub-levers 8 are arranged at gradually increasing distances from the sub-lever pivot, ranging from the center type action outward, to assure a uniform stroke for each type bar I 5. Likewise, the points of connection of the links I to the key levers 5 are at graded elevations increasing from the center outward.

As afore-stated, the sub-levers 8 may be either manually operated, as shown in said Helmond patent, or may be power operated, for example, as shown in said Yaeger patent, No. 2,254,764. In its broader aspect the sub-lever 8 of each type action constitutes an actuating member thereof, in that the manner of actuating the pull link l6, whether by a sub-lever as shown, or by other actuating means, is not important to the practice of the invention. It is however essential that the connection points ll of the actuating members be positioned to accommodate the prescribed arrangement of the links, as later described.

The type bars ll when inactive assume the positions shown in Figure 1 with their forward ends lying against a usual type-bar rest, not shown, which is supported on the segment I3 to move the entire type-bar basket therewith in case shifting. The type bars II are guided by the usual radial slots IS in the segment, Figure 3, to strike at a common typing point indicated at T in Figures 1 and 3. The usual type guide, not shown, may serve to further guide the type so as to strike accurately at said point. It may be here noted, with reference to Figure 1, that the typing point T in the embodiment shown is at the point of tangency of a line in a central vertical plane fore-and-aft of the typewriter, tangent with the platen 20 and extending through or relatively close to the axis of the pivot rod i2. Said typing point is further indicated as being at the intersection of a construction line A with the periphery of the platen and passing through the platen axis.

Erasures made on the work sheet resting against the platen 20 result in much of the eraser dust falling against the segment 13 and lodging to a large extent in or about the pivot slots is where an accumulation becomes detrimental to proper operation of the typewriter. the eraser dust from reaching the type bar pivotal mounting, a shelf-like projection or dust shield 22 is provided. This dust shelf is just above the array of pivot slots 58 and may be arouate and concentric with the pivot rod 12. In order to clear the dust shield 22 as the type strikes the platen, the type bar I l is substantially arched as indicated at 23. Because of the closeness of the dust shelf 22 to the pivotal mounting of the type bars, it is necessary that the arched portion 23 start abruptly just beyond the type-bar pivot, at which portion, also, a shoulder 24 of the type bar is arranged to engage a universal bar 25 for operating the letter-feed mechanism. The abruptness and close proximity of the arched portion 23 to the type-bar pivot 12 makes the problem of clearance between each type bar and its pull link :6 more acute, since the outer edge of the type bar at said arch bows out appreciably from the body of the type bar.

In the embodiment of the invention illustrated, the means for guiding the segment l3 for caseshift movement, except as to certain features of arrangement hereinafter set forth, is like that described and claimed in the Helmond patent, No. 2,306,604, to which reference is had for details not shown herein. As is the usual practice, the segment is is normally suspended by spring means, not shown, in its upper position in which the type of the lower case on the type bars II are adapted to strike the typing point T, and from which the segment is shifted downwardly to cause the other or uppercase of type to strike at said point. The segment 13 is secured to a segment frame 21, the upper portion of which is guided for case-shift movement by a ball-andraceway unit 28 at each side of said frame. Said units each comprise raceways respectively on the segment frame and on a member 29 of the typewriter mainframe. The two balland-raceway units 28 constitute guiding means for the upper part of the segment, causin said part to move in a path indicated by the line 30 in Figure 1, as later described.

The segment frame 2'! has at each side thereof a downwardly reaching leg 3|, Figure l, on each of which a roller 32 is rotatably mounted. Each roller 32 rides between front and rear guide faces 33 of a member 34, and each of said members is secured to a crossbar 35 of the typewriter. The rollers 32, the members 34 and the crossbar 35 constitute a guiding means for the lower portion of the segment, by which the axis of said roller To prevent v is caused to follow a path indicated by the line 35, later described.

To assure equal movement of each lateral portion of the segment frame during case shifting, a bail 38 is provided, a cross-shaft 39 of which rigidly connects the two arms 40 and is pivoted at M on the typewriter mainframe. Since the segment frame 2? moves in a path not concentric with the axis of pivots ll, a sliding connectionbetween the bail arms 46 and the segment frame is provided. This may take the form of a shoe 42 rockably secured to each bail arm and slidable in a groove in each lateral edge of the segment frame. Thus, the bail 38 will cause the segment frame to case shift with a parallel-motion and yet will not influence the direction of case-shift movement, this being the combined function of the upper guiding means 28 and the lower guiding means 3235.

The mechanism for actuating the type-bar segment i3 in case shift may be of any suitable kind. That shown herein in Figure 1 comprises a shift key lever d3 similar to the key lever 5 but having a hook portion M which engages a stud 45 on a shift arm &5. The shift arm 46' is pivotally mounted at its forward end, the other end being operatively connected by a link 4? to the leftward leg 3% of the segment frame 21. Depressing shift key lever 43 will cause the shift 5 to swing clockwise about its pivot and thus the type-bar segment downward.

The present invention provides a type-action system arrangement and a segment case-shift guidingmeans coordinated therewith, by which an appreciably angular spacing is afforded between the type bar I l as a Whole and its pull link it. From one aspect, this enables disposing the type-car segment at an appreciable angle consistent with a typing point that is substantially above the level of the platen axis, and yet permits the links if? to remain at about their horizontal positions. Or if desired, the principles of the invention. will accommodate an arrangement of the pull links it that inclines substan-' tially downwardly from the connection l5 of the type bar, while maintaining the type bar in its previous horizontal position and the segment in its approximately vertical position consistent with a typing point that is about at the level of the platen. The arrangement of the elements of the type-action system, particularly the segment l3 and the links l6 as illustrated in Figure 1, is in effect a combination of these features of arrangement. That is, the segment [3 is disposed at an appreciable angle from the vertical, and the links are in lined somewhat from the horizontal.

From another aspect, the provision of an ap-' preciable angular spacing between the type-bar lever and its pull link it has the advantage of accommodatin bowed or arched type bars and thus enables the use of the dust shelf 22, in a segment-shift typewriter. As before mentioned, the close proximity of the arched portion 23 to the type-bar pivot l2 causes the type bars, particularly at or near the center of the machine, to project into the region heretofore occupied by the pull links in their substantially parallel relation to the type bars.

As shown in Figure l, the link connections 5 to each of the type-bar operating arms it move in a generally up-and-down direction during case shifting, and this movement in turn causes each of the straight pull links it to oscillate. between the two positions shown respectively in full and dot-and-dash outline. The construction line B relates only to the link it of the medial; type action. Said line bisects the angle of. vibration of that link It and thus indicates the center-line of oscillation of said link, intersecting the pivotal point I? and extending rearwardly therefrom. Line B is a construction line similar to line B except that it relates to the link [6 associated with the outermost. type action of the system. The construction line B shown in Figure 2 is the same as the line 13 shown in Figure 1 except that it relates to the outermost type action at the opposite or right side of the typewriter. In Figure 3 the line B is a construction line like line B but relates to a type action intermediate the medial and outermost type actions' It will be recalled with reference to Figure 1 that the construction line A extends from the typing point T rearwardly through the axis of the platen 20. to Figure 2 that said line A is in a central vertical plane fore-and-aft of the typewriter. Said line A extends rearwardly to a point of convergence C, at which point the lines B, B and 1% relating to the links it of all the type actions converge. It will now be seen, in view of. the arcuate arrangement of the link connections I? to the sub-levers 8, that the lines B, B and B extending from all of the connections l1 to the point of convergence C, collectively form a conical contour. The apex of the cone thus formed is at the point C and the line A is the center-line or axis of the cone.

A horizontal line I), Figure 2, at right angles to the line A and passing through the point of convergence C, defines an axis which forms the basis for coordinating the case-shift guiding means with the type-action system and with the typing plane on the platen. That is to say, the means for guiding the segment it in case shift is so arranged with respect to the pull links l5 of all of the type bars ii that the points of connection move in prescribed paths such as will avoid the transmission of any motion to the sublevers 8 and thence to the key levers 5. The arrangement of the segment-guiding means further assures that both cases of type on the type bars I! will approach the typing point, to strike the platen, on a line radial with the axis of the platen at said point.

To accomplish this coordination, the segment 53 during case shift moves in an arcuate or cylindrical path, the curvature of which is concentric with the axis D which, as stated, coincides with point of convergence C. Since the shift movement of the segment is determined by the upper guiding means 28 and the lower guiding means: 32-32%, it follows that the paths of travel generated. by these guide means, respectively, are concentric with said D. That is, with re spect to the two upper guide units 23 at the sides of the segment, the line of travel 3d determined by each unit 28 is an arc struck from the center or axis D. Likewise, with respect to the two low or guide units 3235 at the opposite sides of the segment frame, the line of travel 36' determined by the guide faces 33 of each lower unit:

is an arc, the center of which is the axis D.

By causing the segment l3 to case shift in a cylindrical path concentric with the axis D on which-the point C lies, the connection points l5 of each pull link IE will be caused to move in paths also concentric with the axis D. In that the center-line of oscillation B, considering only the central type action for example, radiates It will be noted with reference.

from the point C, it follows that the path taken by that connection I is substantially normal to, or at right angles with, said line B. It will be seen that said path coincides substantially with an arc struck from the point ll, through the upper and lower positions of point 15, and that therefore practically no motion will be transmitted through link 16 during or incidental to the caseshift movement of point l5. With regard to the typing point T on the platen 20, it follows that, because the segment moves in a path concentric with the axis D, and because of the fact that the line A passing through the platen axis and the typing point radiates from the point C on axis D, both the upper and the lower case of type will approach the platen on the radial line A and will meet the platen on a plane tangential thereto at the typing point.

Considering the very short extent of caseshift movement, about one quarter inch in most typewriters, particularly in relation to the large radius of curvature of the path of point l5, tak ing the medial type action for example, it will be seen that said path as generated by the upper and lower guide means respectively may be in a straight line. It is necessary, however, that said straight line path be at right angles to the line B. This result will be had if the path 36 described by each lower guide means 3235, instead of being a curve from the axis D, be on a straight line which forms a chord of said arc, intersecting the upper and lower points defining the two positions of the axis of roller 32. The same applies as to the path 35 of the upper guide means 23. That is, instead of being curved on the axis D, said path may lie in a straight line which forms a chord of the arc described by said curve. By having the point move in a straight line path, related to the axis D as described, said path will coincide more closely with the arc struck from point ll.

While the above description is confined to the effect of the arrangement of the case-shift guiding means on the central type action, particularly with reference to the link 16 and the construction line B thereof, it will be apparent that a similar eifect is had for all the type actions. That is, the points l5 of the other links l6 throughout the entire type-action system will move in like paths having a similar relation to their respective construction lines B and B since all said construction lines converge on the point C and since said point is on the axis D upon which the path of movement of the typebar segment is based.

Having thus described the invention, what is claimed is:

1. In a typewriter type-action system, a cylindrical platen, a series of type bars each having an operating arm, means including a segment pivotally mounting said type bars to strike at a common typing point on the platen, a series of straight pull links connected respectively to said type-bar operating arms, the arrangement of said operating arms and said pull links with respect to the body of the type bars when inactive being such that said pull links are relatively close to and beneath the body of the corresponding type bars, means for guiding said segment in caseshift movement, and a series of actuating members connected to the forward ends of said pull links, said actuating members being non-caseshiftable, said pull links therefore oscillating during case shift to accommodate the shift movement of the type bars, each link having a construction line extending from its point of connection to the actuating member and bisecting the angle of oscillation, the arrangement of all the links being such that their construction lines converge substantially at a common point, said point of convergence lying in a fore-and-aft center-line of the typewriter extending from the typing point and intersecting the axis of said platen, said point of convergence also lying in a horizontal axial line normal to said center-line, said case-shift guiding means being adapted to guide the segment in a path substantially concentric with said axial line.

2. In a typewriter type-action system, a cylindrical platen, a series of type bars each having an operating arm, means including a segment pivotally mounting said type bars in a curved array to strike at a common typing point on the platen, a series of straight pull links connected respectively to said type-bar operating arms, the arrangement of said operating arms and said pull links with respect to the body of the type bars when inactive being such that said pull links are relatively close to and beneath the body of the corresponding type bars, means for guiding said segment in case-shift movement, and a series of actuating members connected to the forward ends of said pull links, said actuating members being non-case-shiftable, said pull links therefore oscillating during case shift to accommodate the shift movement of the type bars, each link having a construction line extending from its point of connection to the actuating member and bisecting the angle of oscillation, the arrangement of all the links being such that the construction lines thereof collectively define a conical contour, the apex of the cone being in a center-line of the typewriter extending rearwardly from the typing point and intersecting the axis of said platen, said cone apex substantially coinciding with a horizontal axial line normal to said center-line, said case-shift guiding means being arranged to guide the segment in a path substantially concentric with said axial line.

3. In a typewriter type-action system, a cylindrical platen, a series of type bars each having an operating arm, means including a segment pivotally mounting said type bars in a curved array to strike at a common typing point on the platen, a series of straight pull links connected respectively to said type-bar operating arms, the arrangement of said operating arms and said pull links with respect to the body of the type bars when inactive being such that said pull links are relatively close to and beneath the body of the corresponding type bars, separate means for guiding respectively the upper portion and the lower portion of the segment in case-shift movement, and a series of actuating members connected to the forward ends of said pull links, said actuating members being non-case-shiftable, said pull links therefore oscillating during case shift to acc0mmodate the shift movement of the type bars, each link having a construction line extending from its point of connection to the actuating member and bisecting the angle of oscillation, the arrangement of all the links being such that their construction lines converge substantially at a common point, said point of convergence lying in a center-line of the typewriter projecting rearwardly from the typing point and intersecting the axis of said platen, said point of convergence also lying in a horizontal axial line at right angles to said center-line, each of said segment guiding means defining paths of movement for the respective portions of the segment that are cylindrical and concentric with said horizontal axial line,

4. In a typewriter type-action system, a cylindrical platen, a series of type bars each having an operating arm, means including a segment pivotally mounting said type bars in a curved array to strike at a common typing point on the platen, a series of straight pull links connected respectively to said type-bar operating arms, the arrangement of said operating arms and said pull links with respect to the body of the type bars when inactive being such that said pull links are relatively close to and beneath the body of the corresponding type bars, separate means for guiding respectively the upper portion and the lower portion of the segment in case-shift movement, and a series of actuating members connected to the forward ends of said pull links, said actuating members being non-case-shiftable, said pull links therefore oscillating during case shift to accommodate the shift movement of the type bars, each link having a construction line extending from its point of connection to the actuating member and bisecting the angle of oscillation, the arrangement of all the links being such that their construction lines converge substantially at a common point, said point of convergence lying in a center-line of the typewriter projecting rearwardly from the typing point and intersecting the axis of said platen, said point of convergence also lying in a horizontal axial line at right angles to said center-line, each of said segment guiding means defining paths of movement for the respective portions of the segment that are each normal to a plane intersecting said horizontal axial line and midway of the limits of case shift at each portion.

5. In a typewriter type-action system, a cylindrical platen, a case-shiftable segment, a series of type bars pivoted in an arcuate array on said segment to strike at a common typing point on the platen, said segment having a dust shelf projecting forwardly therefrom circumjacent the arcuate type-bar pivot array, each of said type bars being arched so as to clear said dust shelf when the type bar types, each of said type bars having an operating arm extending rearwardly and downwardly from its pivot, a series of sublevers having upstanding lever arms forward of the type-bar pivots, a series of straight pull links connecting the type-bar operating arms and the sub-lever arms, said pull links being each disposed at an appreciable angle from the body of the corresponding type bar so as to afford space for the arched portion of the type bar, said sublevers being non-case-shiftable, said pull links therefore oscillating during case shift to accommodate the shift movement of the type bars, each said link having a construction line extending rearwardly from its point of connection on the sub-lever arm and bisecting the angle of oscillation, the arrangement of all the links and sublever arms being such that the construction lines of the links converge substantially at a common point, said point of convergence lying in a centerline of the typewriter extending rearwardly from the typing point and passing through the axis of the platen, said point of convergence being in a horizontal line normal to said center-line, and means to guide said segment for case-shift movement in a cylindrical path the axial center of which coincides substantially with said horizontal line.

6. In a typewriter type-action system, a cylindrical platen, a case-shiftable segment, a series of type bars pivoted in an arcuate array on said segment to strike at a common typing point on the platen, said segment having a dust shelf projecting forwardly therefrom circumjacent the arcuate type-bar pivot array, each of said type bars being arched so as to clear said dust shelf when the type bar types, each of said type bars having an operating arm extending rearwardly and downwardly from its pivot, a series of sublevers having upstanding lever arms forward of the type bar pivots, a series of straight pull links connecting the type-bar operating arms and the sub-lever arms, said pull links being each disposed at an appreciable angle from the body of the corresponding type bar so as to afford space for the arched portion of the type bar, said sub-levers being non-case-shiftable, said pull links therefore oscillating during case shift to accommodate the shift movement of the type bars, each said link having a construction line extending rearwardly from its point of connection on the sub-lever arm and bisecting the angle of oscillation, the arrangement of all of the links and sub-lever arms being such that the construction lines of the links collectively define a conical contour, the apex of which is in a center-line of the typewriter extending rearwardly from the typing point and passing through the axis of the platen, and means to guide said segment for case-shift movement in a generally cylindrical path the axial center of which is on a horizontal line transverse of the typewriter and at or near said conical apex.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,034,554 Yaw Aug. 6, 1912 1,568,736 Hokanson Jan. 5, 1926 2,184,736 Dobson Dec. 26, 1939

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