US2175602A - Typewriting machine - Google Patents

Description

Oct. 10, 1939.

. E. S. HALL TYPEWRITING MACHINE Filed Aug. 6, 192'? 4 She ats-Sheet 2 IN V EN TOR. (26M 5: M

A TTORNEYS.

Oct. 10, 1939. 5,5, HALL 2,175,602

TYPEWRITING MACHINE Filed Aug. 6, 1957 4 Sheets-Sheet 3 IN VEN TOR.

A TTORNEYS.

Oct. 10, 1939. s, HALL 2,175,602

TYPEWRITING MACHINE Filed Aug. 6, 1937 4 Sheets-Sheet 4 Fifi 9- INVENTOR. BY m5. W W 1 ATTORNEYS.

Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE mnwnrrmc MACHINE Y Edwin s. Hall, New navenfconn. Application August 8, 1937, Serial No. 151,741 23 Claims. (oi. 191-27) This invention relates to typewriting machines. Modern typewriter manufacture has attained a high degree of excellence and much progress has been made in reducing the noise of opera- I tion. In the so-called noiseless machines, the noise of impact of the type with the platen is reduced usually by checking the velocity of the type with a straightening toggle before the type reaches the platen, and then pressing it home 10 either by a direct linkage with the key lever or by using the kinetic ener y given up by the stopping of a rapidly moving weight. Type bar actions of this nature have been highly perfected and do excellent work, but their touch is not ll liked by some operators and they seem to be of such nature as to preclude the use of a case shift of the segment type, requiring that the carriage be raised or lowered for case shift purposes. Case'shift mechanisms which raise or I lower the carriage are heavier in operation, more tiring to hands and eyes of the operator, and tend to be more noisy than those which raise or lower the segment in which the type bars are pivoted. In fact, modern typewriters of the 25 ordinary front-strike variety, by the use of a quiet segment shift and by quieting the escapement and other sources of mechanical noise, are now more quiet than the noiseless machines in every respect save that of the noise of impact I) of the type on the platen. Anobject of this invention is to provide a different and better method of, quiet printing in a typewriter, using the end thrust of a toggle directly to obtain the printing,

pressure with a rolling contact of the type with 36 the platen, and permittingsimpler and quieter shift means, independent of both carriage and segment, for selecting which type character of a given type bar is to be printed.- A further object is to provide a type bar action of such nature a as to permit the use of two or three times the I usual number of type characters on-each type bar, either to permit the number of type bars to be correspondingly reduced, or to make it possible for an oflice or portable typewriter to have 45 two type faces instead of .one, or many more characters as desired, all under immediate and convenient control of the operator.

v More specifically, vobjects of this invention are: To provide an improved and relatively silent 50 or noiseless method of printing in a typewriter 'by using- 'a rolling contactof the type on the platen-, theapproach of the type to the platen beingzej substantially tangential rather than normal; i To provide an improved method of printing in a typewriter by the direct application of the potential pressure or end thrust of atoggle type bar as it is driven over-center, to produce cleancutprinting' and an ample number of carbon copies'quietly and rapidly with a rolling contact v of the type with the platen;

To provide an improved method of printing in a typewriter such that the uniformity of strength of the type impressions will depend more upon the machine itself and less upon the uniformity of touch of the operator;

To provide an improved method of printing in a typewriter by rolling the type impression onto the platen on both the forward and the return strokes of the type-bar; 1

To provide an improved method of printing with a rolling contact by rolling the type impression onto the platen on one stroke only of the type bar, the type being withdrawn from the platen on the other stroke;

To provide an improved method of shifting from lower to upper case in a typewriter by use of a control member independent of and without raising or lowering either the platen or the segment in which the type bars are pivoted;

To provide improved type bar and case shift actions for carrying out these improved methods;

To provide type bar actions in which each type bar consists of two members, the bar itself and a separate type carrier pivoted thereto; 80

To provide type bar actions in which the motion of approach of the type is essentiallytangential instead or normal to the platen, and in which the printing pressure is obtained by a rolling or toggle action as the type carrier rolls past the printing point; v

To provide type bar actions in which the type carrier has a cycloidal movement, the type itself following a portion of a hypocycloid while approaching the platen, so that, while printing, the 0 instantaneous axis of rotation of the type carrier is the printing point; I

To provide type bar actions in which, when shifting from lower to upper case with the usual shift key, neither the platen nor the segment in 46 which the type bars are pivoted need be raised or lowered, the shift being made by moving a control element independent of both carriage and segment; g

To provide type bar actions in which it is con 50 veniently possible tb have more than the usual two or three characters on each type bar, together with convenient and easily operable means for selecting which of the several characters is to be printed upon operation of the corresponding k y;

To provide type bar actions in which, with two or three pairs of characters on each type bar, it is possible to predetermine which pair is to be used, and then shift from one character to the other of that pair by the usual movement of the shift key;

To provide a type bar action which, by the use of an over-center toggle type bar, is capable of rolling the type impression onto the platen on the forward stroke of the type barwithout touching the type to the paper on the return stroke;

To provide fast, effective, and efficient type bar and case shift actions, relatively simple and direct, consisting of few parts, and capable of being built within the limits of relatively small machines.

Briefly described, the invention consists essentially of pivoting the type bars in a segment coplanar with the axis of the platen so that the type bars swing substantially tangent to the platen instead of normal to it. Each type bar comprises two members, pivoted together, arranged to form a toggle, to roll the type impression onto the platen as the toggle goes 'overcenter. Various means may be provided to control the rolling action of the type, including internal gearing, planetary gearing, and cycloidal cams, the timing of the gears or the positioning of the camsbeing used to control the case shift or other selection of which type character of a given type bar is to be printed upon operation. This improved shift control or selection mechanism, being independent of both carriage and segment, can be light and quiet. in operation and can have a wider range, permitting the convenient use of four or more characters on each type bar instead of the usual two.

.In the drawings, Fig. 1 is a sectional elevation of an embodiment of the invention, illustrating the principle thereof; Fig. 2 is a plan-view of some of the parts of Fig. 1; Fig. 3 is a sectional elevation of another embodiment of the invention; Fig. 4 is a plan view of some of the parts of Fi 3; Fi 5 is a sectional elevation of another embodiment of the invention, similar essentially to the embodiment of Fig. 3; Fig. 6 is a plan view of some of the parts of Fig. 5; Fig. 7 is a sectional elevation of another embodiment of the invention; Fig. 8 is a front view of the type guide assembly of Fig. 7; and Fig. 9 is a plan view of some of the parts of Fig. '7.

Referring to the drawings, a different emb'odiment of the invention is shown oneach of the four sheets. In each case, the carriage, paper, ribbon, ribbon vibrator, and various other parts have been omitted for clearness' in the drawings,

but it is understood that the platen should be mounted on a carriage in a well-known manner,

and that the paper, ribbon, etc. should be provided as usual.

Referring to Figs. 1 and 2, platen l and arcuate segment pivot rod l3 are mounted in coplanar relationship in frame I l, the axes of platen Ill and segment pivot rod I3 being in a conunon horiis fixed on frame adjacent the printing point on platen III, to position the type when printing and to form a reaction surface for the side thrust of the type bars toward the ends ofthe'segment Type guide I].

whose thrust cannot be normal to platen II). Type guide I! may also serve as a support or track for the ribbon vibrator (not shown) in the usual manner.

Each type bar l2 carries a type wheel l6 pivoted thereon. Each type wheel I6 may have six or more type characters on the ends of its radiating arms 28. Each type wheel l6 has a pinion l8 fixed thereto and in mesh with idler l9, also pivoted on type bar l2, and in mesh with sun gear 20. Sun gear 20 is pivoted adjacent to type bar l2 on segment pivot rod I3, and all the sun gears 20 (one for each type bar l2) are in mesh with arcuate rack 2|. Rack 2| is urged upward by springs 22 and is positioned by link 23 having hooks 24 engaging pin 25 on rack 2|. Link 23 is connected to shift key lever 26.

In operation, because of the coplanar relationship of platen l0 and arcuate segment pivot rod 3, type bars I2 swing in an are substantially tangent to platen l0 instead of in the usual normal manner.

If any type wheel l6 could roll without slipping and in proper timed relationship on the inside of a spherical surface whose section would be indicated by the broken line 21, one of the type characters of type wheel [8 would roll its impresslon onto the paper on platen I0 while type bar l2 passes the position where its axis intersects the axis of platen Ill. By changing the timed relationship, another of the type characters could be selected to be printed upon operation of key lever IS. A segment of a spherical internal gear, or of an annular crown gear, might be used with the radial arms of type wheel I6 as gear teeth meshing directly therewith, but the pitch surface of such a gear should be tangent to the printing point on platen l0, wherefore its teeth would have to be cut away in the region where they are most needed. Moreover such a gear would not be adaptable to changing the timing to select which of the type characters of type wheel I6 is to be printed.

Type wheels I6 can, however, be made to roll as though in mesh with such a gear, by planetary gearing as shown, the proportions of the various parts being correctly chosen. When key lever I is depressed, type bar |2 swings upward, idler gearlfl rolls around stationary gear 20 and drives pinion I8, which causes type wheel l6 to roll without slipping on are 21, until one of the type characters is impressed upon the paper on platen H) by toggle action of type bar l2 and wheel I6 as wheel l6 rolls by. Type bar |2 need be raised only enough to print the upper edge of the type character, and then it may be permitted to return toward the rest position, reinforcing the type impression as it starts on the returnstroke. If shift key lever 25 had been depressed before key lever l5 had swung into printing position, the timing of type wheel I 6 would have been changed by the corresponding movement of rack 2|, sun gear 20, idler l9, and pinion I8, so that the next type character below that printed would have been selected for printing instead. To select either of the other two pairs of type characters on type wheel Hi, link 23 may be changed to a another hook 24 on pin 25, moving rack 2| to a different position, adjusting sun gears 20 and setting type wheels IS in a different timed relationship. Thus three different type faces or sets of type characters ,could be used on one machine, the shift from one type face to another being managed by change of the setting of link 23 relative to rack 2|, and the shift from lower to upper case in any of the three type faces being made by the shift key in the usual manner.

Referring to Figs. 3 and 4, platen 30 and arcuate segment pivot rod 33 are mounted in coplanar relationship in frame 3|, their axes being in a common plane. Type bars 32 are pivoted on rod 33 and are actuated by links 34 connecting with key levers 35. Type guide 31 is fixed adjacent the printing point on platen 3,0 to guide the type when printing to resist side thrust of the fcranked" type bars, and to support the ribbon vibrator in the usual manner.

To each type bar 32 is pivoted a type carrier 36 having preferably four or more different type characters on the ends of radiating arms 38. On anothe radiating arm of type carrier 36, roller 39 is perably mounted. Expanding spring 40 norm lly holds carrier 36 in such a position relative to type bar 32 that, upon operation of type bar-32, its roller 39 will engage cam 4| which is mounted in frame 3| in such a manner that it can be rotatably positioned in several positions about the center of pivot rod 33 as a center. Arcuate tail rod 42 of cam 4| is engaged by bellcrank 43 which is freely pivoted on jackshaft 44.

Arm 45 is fixed on jackshaft 44 and is connected by link 46 to shift key lever 41. Notched arm 43 is also fixed on jackshaft 44 and its notches may be engaged by latch 49 of bellcrank 43 to lock bell crank 43 to jackshaft 44 in either desired position.

In operation, because of the coplanar relationship of platen 3B and arcuate segment pivot rod 33.

type bars 32 swing in arcs substantially tangent to platen 30 instead of in the usual normal manner. When any key lever 35 is depressed, its corresponding type bar 32 swings downward and its roller 39 engages cam 4|, the engagement being quiet because cam 4| is substantially tangent to the path of roller 39 at engagement. The contour of cam 4| then curves easily into a hypocycloid such that, by its action on roller 39, each of the type characters on arms 38 is caused to follow another hypocycloidal path, the type character pre-selected for printing following that path which reaches platen 30 at the printing point when the pivot center of type carrier 36 on type bar 32 passes thru the plane common to the axes of platen 30 and segment pivot rod 33. At this instant, the instantaneous center about which type carrier 36 is rotating, is the printing point. This rolling action is geometrically the same as that obtained by the gearing shown in Figs. 1 and 2. In either case, the velocity of approach of the type to the platen at the instant of contact is almost zero and the contact therefore quiet, the printing pressure being obtained by the direct application of the end thrust of the toggle formed by the type bar and the type wheel or carrier as the toggle goes overcenter, the platen being set close enough to make the desired pressure.

To select a different type character on another of radiating arms 38, it is only necessary to change the position of cam 4|.

each of the four type arms 33 of each typebar 32. Depressing shift key lever 41, (acting thru link 46, arm 45, iackshaft 44, arm 48, latch 49,

and bellcrank 43), moves'cam' 4| into the next position above that now occupied, and causes the next type character below that shown in printing key lever 41 will move cam 4| into the highest po- 7 Four positions are indicated by the dash lines in Fig. 3, one for sition indicated. In this way the operator may conveniently select which of, the four type characters is to be printed upon operation of the type bar. The same sort of mechanism could be extended to six or more type characters on each type bar. In principle it is the same as that shown in Figs. 1 and 2. In either case, the case shift and the selection of type face, etc. may be obtained without raising or lowering either the carriage or the segment, the control means being independent of both carriage and segment.

The embodiment shownin Figs. 5 and 6 is a further development'of the idea 'illustrated in Figs. 3 and 4, the arrangement and proportions 'of the type bar action being somewhat different.

Platen 50 and arcuate segment pivot rod 53 are mounted in coplanar relationship in frame 5| with I their axes in a common inclined plane. Type bars 52 are pivoted on rod 53 and are actuated by links 54 connecting with key levers 55. guide 51 is fixed adjacent the printing point on platen 50 to guide the type when printing, to resist the side thrust of the "cranked" type bars, and to support the ribbon vibrator (not'shown) in the usual manner.

To each type bar 52 is pivoted a type carrier 56. having preferably four or more different type characters on the ends of radiating arms 58. On,

another radiating arm of type carrier 56, roller 59 is operably mounted. Spring 60 holds roller 59 in the groove of its cam member 6|. A cam member 6| is provided for each type bar 52, and both cam member 6| and type bar 52 are pivoted on segment pivot rod 53, cam member 6| being cleft to straddle type bar 52 in the region of the pivot. 1

Each of the cam members 6| has a roller 62 bearing against an arcuate ramp member 63 so arranged that by its vertical movement, all cam membersSl can be simultaneously positioned rotatably about segmentpivot rod 53. Operating connections between ramp member 63 and the shift key lever are not shown; obviously constructions similar. to those shown in Figs. 1 and 2 connecting rack 2| with shift key lever 26 could be applied whereby the operator could conveniently move ramp member 63 to position 'cam members 5| in any one of the four positions indicated by broken lines in Fig. 5, to select the corresponding type character on arms 58 for print- In operation, because of the coplanar relationship of platen 59 and arcuate segment pivot rod 53, type bars 52 swing in arcs substantially tangent to platen 5B. When any key lever is depressed, its corresponding type bar 52 swings upward, roller 59 following cam 6| to control the motion of type carrier 56 so that one of the type characters on arms 58 is brought into rolling contoggle consisting of type bar 52 and type carrier 56 goes over-center. To predetermine which of the four type characters on type carrier 56 is to be printed, it is only necessa y 9 osition cam 6| in the right one of its four positions. Movement of arcuate ramp member 63 downward from the position shown will shift all cams 6| simultaneously to any desired position.

The fact that the embodiment shown in Figs. 3 and 4, has a down-strike action while this one shown in Figs. 5 and 6 has an rip-strike, doesnot alter the fact that the two embodiments are essentially similar. In both, rolling action of the type while printing is obtained by movement-of a roller mounted on an arm of the type carrier in the diameter of the circle within which it rolls,

and the hypocycloids generated are diameters of the larger circle. The active part of cam 8|, therefore, is a straight line, and when roller 59 follows such a straight path, each of the type characters on the ends of arms 58 follows a similar straight hypocycloidal path as though on the periphery of a circle rolling on the inside of a circle twice the size. Again, at the rolling contact of the type character with platen 50, the velocity of approach of the type character to the platen is almost zero and the contact therefore quiet, the printing pressure being obtained by the end thrust of the toggle consisting of type bar 52 and type carrier 58 as the toggle goes over-center. The type impression is reinforced by the reversed rolling action as type bar 52 starts returning.

Return of the type bar to the position of rest,

upon release of key lever 55, is caused 'by gravity aided by the usual return spring (not shown).

Referring to Figs. 7, 8, and 9, platen l and arcuate segment pivot rod 13 are mounted in coplanar relationship in frame ll, their axes being in a common plane. Type bars 12 are pivoted on rod 13 and are actuated by links 14 connecting with key levers I5. Return springs 81 are provided to return type bars 12 to the position of rest. Type guide 11 is fixed adjacent the printing point on platen to guide the type when printing, to resist side thrust of the cranked type bars, to support the ribbon vibrator (not shown) in the usual manner, and to provide a type guide aperture 18. Nearby the cushion 83 is supported by shift rod 84 which latter is slid- I and lower sides of aperture 19 as internal gear teeth in rolling relationship. The pivotal movement of type carrier 16 on type bar 12 is limited to the region centering on that in which the two members are in line by pin 8| carried by carrier 18 and operable between limits set by ears 82 on the end of type bar 12. C-spring 80 by its compressive action tends to cause type bar 12 and type carrier l8.to buckle one way or the other to the limit of their pivotal action as permitted by pin 8! and ears 82. When in the position of rest, type carriers 16 are supported by cushion 88.

In operation, the position of cushion 83 is determined by that of shift key lever 85. As shown, shift key lever 85 is depressed as for printing upper case lettersand cushion 83 is in its upper position. Upon operation of key lever I5, type bar 12 swings upwardfrom its position of rest to the position shown by dotted lines whereupon type carrier 18 engages cushion 83. Continued upward movement of type bar 12 causes the toggle to straighten, driving the lower radiating arm I8 of type carrier 16 into aperture 18, causing its type character to roll the impression of the type onto the platen as the toggle goes over-center as shown by the short dash lines. after, the printing having been done, C-spring 80 Shortly there snaps the toggle to its bent position as shown by long dash lines, withdrawing the type from the platen. When the key isreleased, return spring 81 helps type bar 12 to swing back downward with sufficient force to drive the toggle over center again when type carrier 16 strikes cushion 88, returning the parts to the position of rest shown in full lines in Fig. 7.

If shift key lever 85 had been in its released position, indicated by dotted lines, cushion 83 would have had a lower position, and upon operation of key lever 15, type carrier 16 would have engaged cushion 83 earlier so that its upper radiating arm 18 would have entered aperture 19, printing the lower case letter. While but two radiating arms I8 for two type characters are shown on each type carrier 16, it is obvious that three or more could be used, and a corresponding number of positions provided for cushion 83 by selector mechanisms associated with shift key lever 85 similar in construction and arrangement to those illustrated in Figs. 1 to 4 inclusive.

Having thus described the invention, it will be obvious that all the objects thereof as above stated have been attained. In each of the four embodiments shown in Figs. 1 to 9 inclusive, the movement of the type bar is essentially tangential to the platen instead of normal to it; the printing is not done by a direct impact but by a rolling contact of the type on the platen (thru ribbon and paper), such a rolling contact being inherently much more quiet than any impact could be; the printing pressure is obtained by the direct application of the end thrust of a toggle as it goes over-center--a simpler and more positive action than to use a toggle to check the velocity of the type and then press it home by other means; the amount of printing pressure is dependent upon the setting of the platen relative to the toggle of the type bar, rather than upon the touch of the operator; more than the usual two characters can be used on each type bar, and the control means for selecting which type character is to be printed is independent of both carriage and segment, lighter and quieter in operation.

While I have shown specific embodiments of the invention, it will be understood that changes may be made in the arrangement and in the construction of the various parts without departing from the scope of the following claims.

I claim:

1. In a typewriter having a platen, a normally stationary type bar comprising two members pivoted together, type on one of said members, and means for swinging said type bar in a manner substantially tangent to said platen and for causing said type to have a rolling contact with said platen.

2. In a typewriter having a platen and a fixed frame, a type bar pivoted to and normally stationary relative to said frame, a type carrier pivoted to said type bar and forming a toggle with said type bar, type on said type carrier, and means for moving said type carrier in such a manner as to cause said type to be impressed on said platen with a rolling contact as said toggle goes over-center.

3. In a typewriter having a platen and a fixed frame, a type bar pivoted to and normally stationary relative to said frame, a type carrier pivoted to said type bar, type on said type carrier, and means for moving said type along a cycloidal path as it approaches said platen so that, while printing, the instantaneous axis of rotation of said type may be the printing point on said platen.

4. In a typewriting machine, a fixed frame, a platen operably mounted on said frame, a plurality of type bar members normally stationary relative to'said frame, pivots for said type bar members in said frame, the axes of said pivots and of said platen being in a common plane, type characters carried by said type bar members, means for swinging said type bar members toward said platen, and means for causing said type characters to print on said platen with a rolling contact.

5. In a typewriting machine, a frame, a platen operably mounted on said frame, type barmembers, pivots for said type bar members in said frame, a plurality of pairs of type characters on each of said type'bar members, means for predetermining which of said pairs of type characters is to be available for printing, and means including a shift key lever for predetermining which type character of a given pair is to be' printed upon operation of a typebar member, both said predetermining means being independent of and requiring no relative movement between said platen and said pvots.

6. In a typewriting machine, a frame, a platen operably mounted on said frame, type bar members, pivots for said type bar members in said frame, a plurality of pairsof type characters radially positioned on the'ends'of each of said type bar members, means forpredetermining which of said pairs ,pf type characters is to be available for printing, and means including a shift key lever for predetermining which type character of a given pair is to be printed upon operation of a type bar member, both said predetermining means being independent of and requiring no relative movement between said platen and said pivots.

'7. In a typewriting machine, a frame, a platen operably mounted on said frame, type bar members, pivots for said type bar members in said frame, type carriers pivoted upon said type bar members, a plurality of pairs of type characters on said carriers, means for predetermining which of said pairs of type characters is to be available ,for printing, and means including a shift key lever for predetermining which type character of a given pair is to be printed upon operation of a type bar member, both said predetermining means being independent of and requiring no relative movement between said platen and said pivots.

8. In a typewriting machine, a platen, 'a plurality of type bars, a type wheel pivoted on each of said type bars, a plurality of type characters on each of said type, wheels, and gearing for controlling the rotation of any type wheel during movement of its type bar into printing position relative to said platen, so as to cause one of sa d type characters to roll its impression onto said platen.

9. The invention as described in claim 8, with means for timing said gearing to select which one of said type characters is to be printed.

0. In a typewriting machine, a platen, a plurality of type bars, a type carrier pivoted on each of said type bars, a plurality of type character's radially arranged on each of said carriers, a cycloidal cam member, and-means on each of said carriers for operably engaging said cam member upon movement of said carrier toward said platen to cause said type characters to follow cycloidal paths on approaching said platen.

11. The invention according to claim 10, with 'carriers is to be printed upon operation.

12. In a typewriting machine, a frame, a platen operably mounted on said frame, a type guide 5 member fixed to said frame adjacent said platen, a plurality of type bars operably pivoted in said frame, a type carrier pivoted to each of said type bars, a plurality of type characters radially arranged on each of said carriers, a cam member, and means on said carriers for operably engaging said cam member upon movement of said carrier toward said platen, said cam member and said means being so constructed and arranged as to cause one of said type characters to have a rolling contact with said platen as said type character passes saidtype guide member. I

13. The invention as claimed in claim 12, with means including a shift key lever for positioning said cam member to select which of said type characters on any of said type carriers is to be printed upon operation.

14. In a typewriting machine, a fixed frame, a platen operably mounted on said frame, a plurality of type bar members pivoted to and normally stationary relative to said frame, each of said members comprising a type bar and a type carrier pivoted to said type bar and forming therewith a toggle and type characters radially positioned on the end of said carrier, and means so for causing one of said type characters to print on said platen with a rolling contact as said to gle goes over-center.

15. In a typewriting machine, a platen, a plurality of type bar members each comprising a type bar and a type carrier pivoted to said type bar and forming therewith a toggle and type characters radially positioned on the end of said carrier, means for causing one of said type characters to print on said platen with a rolling contact as said toggle goes over-center on one stroke of said type bar member while preventing any printing during the. return stroke thereof, said means comprising spring means urging said toggle in either direction away from its straightened position.

16. In a typewriting machine, a platen, a plurality of type bar members, a plurality of type characters on each of said type bar members, a type guide member adjacent said platen, an aper- 5 ture in said type guide member substantially defining the printing point on said platen, and means for causing any desired one of said type characters to enter said aperture to print upon said platen witha rolling contact upon operation of the corresponding type bar member.

17. In atypewriting machine, a platen, a plurality of type bar members, a plurality of type characters on each of said type bar members,

a type guide member adjacent said platen, saideo guide member having an aperture therein, means for-causing one of said type characters to print upon said platen with a rolling contact through said aperture upon operation of its type bar member, and means for selecting which of said 05 type characters shall enter said aperture for. printing upon said operation.

8. In a typewriting machine, a frame, a platen operably mounted on said frame, a plurality of type bar members each comprising a type bar (0 and a type carrierv pivoted to said type bar and forming therewith ,a toggle and a plurality of type characters radially positioned on the end of said carrier, pivots for said type bar members on said frame, means for causing one of-said type char- (5- acters to print on said platen, and means for predetermining which of said'type characters on a given carrier is to be printed upon operation of the corresponding type bar member, said predetermining means being independent of and requiring no relative movement between said platen and said pivots.

19. In a typewriting machine, a frame, a platen, a plurality of type bar members each comprising a toggle and each carrying a plurality of type characters at one end and pivoted to said frame at the other end, a type uide adjacent said platen, a stop associated with said type guide for limiting the motion of the type carrying end of any type bar member whereupon further motion of said member causes its toggle to go overcenter while printing one of said characters, and

shift means for controlling the position of said stop to predetermine which of said type characters will be printed. v v 20. In a typewriting machine, a frame, a platen, a plurality of type bar members each comprising a toggle and each carrying type at one end and pivoted in said frame at the other end, a type guide adjacent said platen, a stop associated with said type guide to limit the motion of the type carrying end of any type bar member whereupon further motion of said member causes its toggle to go over-center during the printing operation, and a stop to limit the return motion of said type carrying end whereupon further motion of said type bar member causes its toggle to reverse over-center to the position of rest.

21. In a typewriter having a platen and type for printing thereon, means for reducing the noise of contact of said type with said platen comprising means for mounting said type for swingable movement in opposite directions toward and for printing thereon, means for reducing the noise of contact of said type with said platen comprising means for mounting said type for swingable movement in opposite directions toward and away from a printing position at said platen along arcs substantially tangent instead of normal to said platen, means for so moving said type, and means effecting rolling contact of said type with said platen upon arrival thereof at said printing position and again upon departure thereof from said printing position.

23. In a typewriter having a platen and a plurality of type carrying members each having a plurality of type characters, means for both predetermining which of said type characters is to be printed upon operation of the corresponding carrying member and for reducing the noise of contact of said type character with said platen, said means comprising means pivotally mounting said carrying members for swingable movement of said type characters in opposite directions toward and away from a printing position at said platen along arcs substantially tangent instead of normal to said platen, means for so moving said members, and control means predetermining which of said characters is to be printed upon operation of its carrying member and effeeling rolling contact of said type character with said platen as it arrives at said printing point.

EDWIN S. HALL.

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