US2353803A - Typewriting machine - Google Patents

Description

y ,1944. H. A. AVERY ETAL TYPEWRITING MACHINE Filed 061;. 50, 1942 4 Sheets-Sheet l ATTORNEY July 18, 1944. H. A. AVERY ETAL TYPEWRITING MACHINE Filed Oct. 30, 1942 4 Sheets-Sheet 2 July 18, 1944. AVERY ETAL I 2,353,803

TYPEWRIIING MACHINE Filed Oct. 30, 1942 4 Shee'ts-Sheet I5 ATTORNEY July 18, 1944. AVERY ETAL 2,353,803

TYPEWRITING MACHINE Filed 001:. 50, 1942 4 Sheets-Sheet 4 4 7 QZHIM ATTORNEY Patented July 18, 1944 TYPEWRITING MACHINE Henry A. Avery, Groton, and Charles Walker, Syracuse. N. Y., asslgnors to L. C. Smith &

Corona Typewriters, Inc., Syracuse, N. corporation of New York Application October 30, 1942, Serial No. 463,932

8 Claims. (Cl.197--1'l) The invention relates to improvements in typewriting machines, and, more particularly, in the type bar actions of such machines.

The principal objects of the invention are to provide an efilcient and compact key-controlled power-actuated type bar action for typewritlng machines; to provide simple, easily operated, and emcient means for varying at will the impression force of the types; to provide an improved type bar action in which the power actuated types print by momentum accumulated by the type bars during their printing strokes and are rapidly returned, all with a minimum of noise; and to improve type bar actions of the kind disclosed in United States patents to. Mansfield C. Crawley, Reissue No. 15,640, No. 1,455,112 and No. 1,503,033 and adapt the same for embodiment in compact form in a type bar case-shifti ng or type bar segment case-shifting machine of the kind disclosed in United States patents to Gabrielson numbered 1,018,968; 1,467,723; 983,490;

1,032,131 and-2,028,200.

Other objects and advantages of the invention will appear from the following description in connection with the accompanying drawings illustrating the preferred embodiment of the invention.

In the drawings:

Figure 1 is a fragmentary side view of the machine with parts broken away.

Figure 2 is a detail top plan view of the type bar actuator retracting means with certain parts broken away.

Figure 3 is a view similar to Figure 1 illustrating the typing action of a type bar.

Figure 4 is a fragmentary top plan view of a part of the mechanism, certain parts being shown in section and others broken away.

Figure 5 is a fragmentary rear elevation of parts of the mechanism, certain parts being broken away.

The improved power-actuated type bar action is shown as embodied in the known L. C. Smith typewriting machine, and only so much of the machine as is necessary to an understanding of the present invention is shown and will be particularly described.

The system of type bar actions and the actuating means therefor are mounted in a suitable stationary main framework of the machine, portions of which shown are designated l0 and certain parts of which are hereinafter specifically referred to. The usual roller platen H is mounted in the usual platen carriage I: which, in turn,

is mounted on themain framework as usual to II travel transversely of the machine for letter feeding or spacing under control of a suitable escapement mechanism, not shown.

The type bars I! (only two of which are shown) of the usual arcuate system of type bars have their pivots l4 located in an are lying in an upwardly and rearwardly inclined plane, said pivots being carried by the usual type bar support or segment IS. The effective types strike on the upper front portion of the platen, each type bar carrying a lower case type I6 and an upper case type I, and the type bar segment being shiftable by suitable case shift means, not shown, downward substantially in the oblique plane in which it lies to condition the machine for upper case typing. The segment is preferably supported as shown in United States Patent No. 2,028,200 to Gabrielson, for such case shifting movement. The type bars are normally supported adjacent their forward ends by the usual obliquel disposed arcuate type bar rest I! which is suppo ed by means, not shown, to shift with segment II.

Each type bar has pivoted thereto at I! above and forward of its pivot It the forward end of a diflferent one of a series of rigid draw links 20 the rear ends of which are pivoted at 2| to the upper ends of a series of sub-levers 22, the links 20 being all of the same length and adapted to swing about their pivots 2| during caseshifting of the system of type bars. The pivots i9 and the pivots 2| respectively lie in obliquely disposed arcs which are concentric with and disposed in planes parallel to that of the type bar segment and the series of type bar pivots H so that, when the .segment is case shifted, the links 20 will hinge about pivots 2| as is common in segment shift machines.

The several sub-levers 22 (only a few of which are shown) are pivoted in slots in a segment 94 fixedly held to framework It and have their pivotal axes 23 located in an are which is of greater radius than that of the series of pivots 2| and is disposed in a vertical plane transversely of the machine. The lower arms of the levers 22 ar so shaped as to normally register or be arranged in a straight row extending transversely of the machine and each such lever is formed forward of its lower arm with a finger 22" permanently bendable or adjustable fore and aft of the machine, the levers being formed of sheet metal adapted for formation of permanent bends therein. These fingers are adapted to engage the upper portions" of cushioning and type bar repulsing leaf springs 24 before the type bars reach printing position on their printing strokes, said spr gs .being arranged in a straight row transversely of the machine forward of the fingers 22 and being secured at their lower ends to a part of the stationary framework I8 of the machine. The construction is such that each lever 22 has two arms of substantially equal effective length.

Eachdever 22 has pivotally connected thereto at 25 the forward end of a diiferent one of a series of rearwardly extending couplers 28, the couplers being arranged in a straight horizontal row across the machine with their pivots in axial register for selective swinging of the couplers up and down about a straight horizontal axial line extending transversely of the machine. Above and to the rear of their pivots the couplers have connected thereto the forward ends of a row of type bar and coupler return springs 21 anchored at their rear ends to a part of the stationary framework l8. These springs normally yieldingly hold the type bars against time bar rest l8 and the couplers against a horizontal coupler rest 28. The couplers in rear of rest 28 extend through and are guided in vertical slots in a coupler guide comb 28 which extends horizontally across the machine, said coupler rest and coupler guide comb being mounted on a part of the stationary framework l8. The rear edge of the coupler rest is undercut as shown at 28", and each coupler is' slightly undercut at its upper end and is nor-' mally located rearward of comb 28 and, at the lower edge of each coupler, the coupler is formed with a rearwardly extending finger 32, the upper edge of which extends rearward from the lowe end of shoulder 3|.

A universal type bar actuator 33, comprising a straight bar extending horizontally across the machine and formed at its ends with pendent side arms, has the lower ends of its side arms fixed to a horizontal rock shaft 34 which, in turn, extends horizontally across the machine and is journaled at its ends at 38 on the main framework l8. The cross bar of the actuator normally overlies and is spaced above all of the coupler fingers 32, and the straight forward edge of the actuator cross bar is normally located above and slightly to the rear of the upper ends of coupler shoulders 3|.

The actuator 33 is rockable forwardly from its normal position to actuate a selected type bar by;

meansof two constantly tensioned pull springs 38 connected at their rear ends to lugs 31 on the side arms of the actuator and extending forwardly and downwardly therefrom with their forward ends anchored to the lower ends of a pair of rock arms 38 pendent from and fixed to a rock shaft 39 adjacent opposite sides of the machine.

42 engaged in one or the other. of a plurality of latching notches 43 in the eccentric periphery of a conversely rotative plate cam 44. Cam 44 is fixed on a short horizontal shaft 48 journaled in the framework I8 and extends transversely of the machine above roller 42.- The cam may be rotated to engage different ones of its notches 43 with roller 42, a handle 48 being for this purpose fixed to the outer or right hand end of the shaft 48 where it is accessible to the typist from the exterior of the machine. Stop fingers 41 and 48 on the cam are engageable with roller 42 to limit maximum rotation of the cam. By engaging the roller 42in different notches in cam 44, the normal tension of the power springs 38 may be varied at will to vary the impression forming impact of the types.

The actuator 33 is retracted to normal position by power superior to that of springs 38 and derived from a constantly rotating shaft 49 which is constantly driven clockwise (as the machine is viewed in Figures 1 and 3) by means of an electric motor (not shown) while the machine is in use. Said motor is mounted on the framework I8 and connected to shaft 48 preferably as shown in Crawley Patent 1,503,033. Shaft 43 extends horizontally transversely of the machine -to the rear of the actuator, is journaled in the framework I8, and has fixed on it right hand end a ratchetwheei 88.

Opposite the ratchet wheel 88 and adjacent thereto there is journaled in the framework l8 a short crank shaft 8| the axis of which is coaxial with that of shaft 48. A pitman 82 has its rear end pivotally and detachably connected to the wrist of crank shaft 8| and has its forward end pivotally and detachably connected to a lug 83 formed on the cross bar of the actuator 33. The front end of the pitman is connected to lug 83 by a pivot screw 84. is formed with a hook 88 engaged over the wrist of crank shaft 8|. A retaining plate 88 has a forked rear end which receives the wrist of the crank shaft and .closes the throat of the hook, the front end of said plate being detachably held to the rear section of the pitman 82 by a clamping screw 81 which passes through a downwardly facing slot in said plate. The pitman comprises two sections having adjacent threaded end portions adjustably connected by a turnbuckle 88 for lengthening and shortening of the pitman to vary the normal or retracted position of the actuator 33. Turnbuckle 88 is locked, with the pitman in adjusted condition, by lock nuts 82.

Crank shaft 8| is adapted to be clutched or connected with shaft 48, for a part of a single revolution, through the medium of the ratchet Rock shaft 38 extends horizontally transversely of the machine at the rear of the keyboard and is journaled at its ends at 48 on the main framewheel 88 and a pawl 88. Pawl, 88 is pivoted substantially midway its ends on a horizontal pivot screw 88 extending transversely of the machine and threaded into an armor pawl carrier 8| which in turn is fixed on the left hand end of the crank shaft to rotate opposite the right hand face of the ratchet wheel. One arm of the pawl has a nose engageable with the teeth of the ratchet wheel, and a torsion spring 82 coiled about the shank of pivot screw 88 has its opposite ends engaged with this arm of the pawl and with the pawl carrier to normally constantly tend to urge the pawl nose into -engagement with the teeth of the ratchet wheel.

Means are provided for manually selectin any desired type bar for actuation and for causing actuation of the selected type bar by the At its rear end the pitman above described power operated mechanism, which means will now be described.

A part of the framework i is formed with a pawl controlling surface 63 which curves downwardly behind and under the periphery of the ratchet wheel concentrically with the coincident axes of the shafts l3 and ii and extends about said axes for somewhat less than 180 degrees. This surface is so disposed that the arm of the pawl 53 opposite the nose carrying am of the pawl is normally engaged with said surface adjacent the upper end of said surface to hold the pawl out of engagement with the ratchet. At this point in the revolution of the crank shaft, the wrist thereof is to the rear of the shaft axis and slightly below dead center or a straight line through the centers of said shaft, screw 54 and the shaft wrist, and the free end of the pawl carrying arm BI is seated upon and held arrested by a spring-cushioned plunger 34. The pawl passes out of engagement with surface 63 and engages the ratchet wheel 50 just before the crank shaft wrist reaches dead center position in front of the shaft axis.

The plunger 64 has two heads and its shank is slidably guided intermediate said heads to move slightly up and down in a bore in the upper portion of a fore and aft rockable arm 65 pivoted at its lower end at 66 on the framework It. Said plunger is normally held at the upper limit of its motion by a still spring 81 adapted to yield momentarily under impact of arm I on the upper head of the plunger. A universal release bar 63 extends straightly and horizontally transversely of the machine and is normally located intermediate the cross bar of actuator 33 and the fingers 32 formed on the type action couplers 26. This release bar 68 is formed with rearwardly extending arms fixed to a rock shaft 69 which is disposed at the rear of said bar and journaled at its ends on framework III. A link pivotally connected at its rear end at H to arm 65 near the upper end of the latter is adjustably and pivotally connected at its forward end with rock shaft 69. This latter connection comprises a normally vertically extending part 12 fixed to and extending above and below rock shaft 59, an upstanding arm I3 pivoted at its lower end at H to the lower end of part 12 for adjusting movement fore and aft of the machine, a clamping screw 15 which extends through a slot 16 in the arm 13 above pivot H and is threaded into the upper portion of part I2 to clamp arm I3 to part 12 in adjusted position, and a pivot screw 95 connecting link 10 to arm 13. 68 and the framework l0 normally returns the release bar 68 and arm 65 to position the plunger 64 in pawl carrier arresting position, said spring normally urging a stop lug 18 formed on the upper end of part 12, forward against a stop pad 19 held to framework Ill.

The release bar 68 is rockable upward and rearward by any coupler finger 32 to disengage the plunger 64 from the pawl carrier by upward swinging of any one of the couplers 26 about its pivot into a position placing coupler shoulder 3| in front of the cross bar of actuator 33 for forward driving of the actuated coupler by the actuator.

The couplers are selectively operable by the type keys 8!) of the keyboard of the machine, which keys are arranged as usual in four stepped banks or rows and are carried on the forward ends of two-arm key levers 3| which extend A return spring 11 connected to release bar fore and aft of the machine. The key levers are pivoted on different ones of four horizontal and fore-and-aft spaced pivot rods 32 which extend transversely of the machine, the key levers for the forward or lowest bank being pivoted on the foremost rod, and those for respective ones of the other banks being pivoted in progressive order from bank to bank on the.

remaining rods in the known manner for substantially equal upward movement of the rear ends of the levers for a given key dip. Return springs 33 connected to framework I0 and the rear ends of the key levers normally hold the forward arms of the key levers up against the usual key lever stop pad 84 carried by a key lever guide comb 93 held to framework Ill. The rear arms of the key levers are guided in the slots of a guide comb 85 held to framework Hi below coupler rest 23, and said key lever arms are engageable with a stop 36 held to said comb to limit upward movement of said rear arms of the key levers.

At the rear of comb 85 each key lever has pivoted thereto at 81 a normally upstanding two-arm thrust lever 83, the lower arm of which is connected by one of a series of rearwardly extending springs 89 to its associated key lever 8| to normally hold the upper arm of the thrust lever .forward against a cushioning stop pad or strip 90 fixed to a thrust lever guide comb 93 which is held to frame l0 and extends horizontally and straightly across the machine. thrust lever 88 is formed at its upper end with a short lateral extension or lug 9i disposed slightly below and engageable with but a single one of the couplers 23.

Upon depression and release of any type key, the following operation takes place:

The thrust lever 88 connected with the key lever whose key is depressed rocks the associated coupler 26 upwardly and the coupler finger 32 rocks the release bar. 68 upwardly to carry plunger 64 rearward out of engagement with pawl carrier 6| by the time coupler shoulder 3| is positioned in front of the cross-bar of actuator 33. Springs 36 then instantly pull the actuator forward to the limit of its forward stroke driving the key-actuated coupler forward, at which time the sub-lever finger 22* of the sub-lever connected with the actuated type bar comes into contact with the associated cushioning and repulsing spring 24 with the type of the actuated type bar spaced appreciably from the paper backed by platen ll, after which the type bar is carried to its printing limit by momentum and then quickly started on its return stroke by the repulsing spring. The printing stroke of the type bar carries the coupler forward out of contact with the thrust lever 88 and the fully advanced actu ator and the release bar and the coupler drops instantly on the coupler rest, releasing the release bar 63 and plunger 64 which move back instantly to normal position under the influence of spring 11.

On the return stroke of the actuated type bar by its associated springs 24 and 21, the coupler will slide under the release bar. If the key is still depressed at this time, the coupler finger will rock the upper arm of the thrust lever rearward below the returned release bar and this arm will snap forward under said finger after the key is released. If the key is quickly released, the coupler finger will slide rearward between the release-bar and the thrust lever. Just before the actuator 33 is fully advanced by springs 36, the pawl Each 59 passes off the lower end of surface 83 and its nose snaps into engagement with a tooth of constantly rotating ratchet III which thereupon drives the crank shaft 5| positively through the remaining somewhat more than one-half of a single revolution until the pawl is kicked out of engagement with the ratchet wheel by coming into contact with the upper end of surface 63. As the pawl is disengaged from the ratchet wheel, its carrier arm ll impacts the restored plunger 64 and is brought to rest after a single revolution of the crank shaft. The actuator is thus retracted by the motor driven shaft against the resistance of springs 38. No matter how long a type key may be held depressed, the associated type bar will be actuated to print and return only once.

We claim:

1. In a typewriting machine of the kind having a main framework, a platen carriage mounted on said framework, a platen on the carriage, and an actuate system of type bars pivoted to swing upward and rearward to the platen to print and bodily shiftable up and down as a unit in the framework for upper and lower case printing, key controlled power actuated means for selectively actuating the type bars comprising, in combination, a system of upstanding sub-levers of the first order, a system of links all of equal length extending fore and aft of the machine with their front ends pivoted to the type bars above and forward of the pivots of the respective type bars and their rear ends pivoted to the upper ends of the sub-levers, the link pivots and type bar pivots lying in concentric arcs which lie in parallel planes, the sub-levers being fulcrumed in the framework to swing fore and aft of the machine about fixed axes with their lower ends in alignment transversely of the machine and their axes so located that each lever has upper and lower arms of substantially equal effective length, a series of identical couplers extending fore and aft of the machine and normally located in a straight horizontal row which extends transversely of the machine, said couplers pivoted at their forward ends to the lower ends of the sub-levers to swing vertically and their pivots being normally coaxial, a system of fore and aft extending key levers of the first order fulcrumed in the framework and extending under the series of couplers, a normally inactive actuator for the couplers vibrative fore and aft of the machine, power means for advancing the actuator a limited distance and retracting it to normal position, means carried by each key lever for swinging a diflerent one of the couplers up ward into the path of forward movement of the actuatorQspring-returned means for holding the power means against actuator vibrating operation releasable by upward swinging of either coupler and freed from contact by a lifted coupler during the printing stroke of the associated type bar, and a straight horizontal row of upstanding leaf springs mounted on the framework forward of the lower arms of the sub-levers, the lower arms of each sub-lever having a pendent fore and aft adjustable finger engageable with the adiacent spring before the associated type bar reaches the platen on a printing stroke thereof, the limit of the forward stroke of the actuator being such that it cannot positively drive the type bar to the printing point. p

2. In atypew'riting machine of the kind having a main framework, 9. platen carriage mounted on said framework, a platen on the carriage, and an actuate system of typebars pivoted to swing upward and rearward to the platen toprlnt and bodily shiftable up and down as a unit in the framework for upper and lower case printing, key controlled power actuated means for selectively actuating the type bars comprising, in combination, a. system of upstanding sub-levers of the first order, a system of links all of equal length extending fore and aft of the machine with their front ends pivoted to the type bars above and forward of the pivots of the respective type bars and their rear ends pivoted to the upper ends of the sub-levers, thelink pivots and type bar pivots lying in concentric arcs which lie in parallel planes, the sub-levers being fulcrumed in the framework to swing fore and aft of the machine about fixed axes with their lower ends in alignment transversely of the machine and their axes so located that each lever has upper and lower arms of substantially equal effective length, a series of identical couplers extending fore and aft of the machine and normally located in a straight horizontal row which extends transversely of the machine, said couplers pivoted at their forward ends to the lower ends of the sub-levers to swing vertically and their pivots being normally coaxial, normally/inactive power actuated means including a universal coupler actuator movable first forwardly and then backwardly in the framework from a normal idle position during a single cycle of operation of the power actuated means, a set of type keys, one for each coupler, and means operable by each type key to swing its associated coupler upward into the path of said actuator, said power actuated means being releasable for a single cycle of operation by upward swinging of either one of the couplers.

3. In a typewriting machine of the kind having a main framework, a platen carriage mounted on said framework, a platen on the carriage, and an actuate system of type bars pivoted to swing upward and rearward to the platen to print and bodily shiftable up and down as a unit in the framework for upper and lower case printing, key controlled power actuated means for selectively actuating the type bars comprising, in combination, a system of upstanding sub-levers of the first order, a system of links all of equal length extending fore and aft of the machine with their front ends pivoted to the type bars above and forward of the pivots of the respective type bars and their rear ends pivoted to the upper ends of the sub-levers, the link pivots and type bar pivots lying in concentric arcs which lie in parallel planes, the sub-levers being fulcrumed in the framework to swing fore and aft of the machine about fixed axes with their lower ends in alignment transversely of the machine and their axes so located that each lever has upper and lower arms of substantially equal effective length, a series of identical couplers extending fore and aft of the machine and normally located in a straight horizontal row which extends transversely of the machine, said couplers pivoted at their forward ends to the lower ends of the sublevers to swing vertically and their pivots being normally coaxial, normally inactive power actuated means including a normally retracted forwardly movable coupler actuator mounted in the rear part of the framework and releasable by either of the couplers upon upward swinging of the coupler into the path of the actuator for a single forward and return movement, a type key for each coupler, means operable by depression of each type key to swing its associated coupler upward into the path of forward movement of the actuator for forward driving of the coupler by the actuator to impart a printing stroke to the associated type bar, the length of stroke of the actuator being such that the forward limit thereof is reached before the type bar reaches the platen, and repulser springs in the framework each e'ngageable by a different one of the sublevers during the final portion of the printing stroke of a type bar connected with the active sub-lever.

4. In a typewriting machine, a main framework, a platen, type carriers movable to and from the platen, upstanding fore and aft swinging sub-levers of the first order fulcrumed in the framework and each connected at its upper end with a diiferent type carrier to move the latter to the platen upon forward movement of the lower arm of the sub-lever and all arranged with their lower ends normally in alignment transversely of the machine, fore and aft extending couplers normally aligned transversely of the machine and pivoted at their forward ends to the lower ends of the sub-levers for up and down swinging movement, a stationary horizontal coupler rest in the framework extending transversely of the machine and upon which the couplers are normally seated, tension springs anchored to the framework and each anchored to a different one of the couplers to normally urge the coupler and the sub-lever and type carrier connected therewith to normal idle position, fore and aft extending type key levers of the first order fulcrumed in the framework to rock up and down and having their rear ends extending under the coupler rest, normally upstanding coupler lifting levers of the first order each fulcrumed on the rear portion of a different one of the type key levers, springs connecting the lower arms of the lifting levers to the respective key levers to urge the upper arms of the lifting levers forwardly, a horizontal stop on the framework extending transversely of the machine and against which the upper arms of the coupler lifting levers are normally held upright by their springs with the upper ends of said levers beneath the respective couplers below and in rear of the coupler rest, each coupler having a rearwardly facing shoulder extending downward from its upper edge and a rearward extension below said shoulder, 9. normally stationary forwardly and rearwardly movable universal type carrier actuator normally overhanging said coupler extensions, each coupler being rockable upward by its lifter to present its rearwardly facing shoulder in the path of forward movement of the actuator for forward driv ing of the coupler by the actuator to impart a printing stroke to the associated type carrier, and power means releasable by lifting movement of either one of the couplers to impart a single forward and return movement to the actuator, said actuator having a straight horizontal bar extending transversely of the machine for driving engagement with the coupler shoulders and normally disposed above and in rear of said shoulders, said power means including means for so limiting the forward movement of said actuator bar that the couplers move forward out of contact with said bar and drop to the coupler rest during the final portion of the printing strokes of their associated type carriers.

5. In a typewriting machine, a main framework,

a type bar actuating bail having a straight crossbar extending horizontally transversely of the machine and pendent side arms-adjacent opposite sides of the machine fulcrumed on the framework at their lower ends to rock about a horizontal axis extending transversely of the machine, a horizontal rock shaft extending transversely of the machine forward of the actuator and Journaled on the framework and having two pendent rock arms fixed thereto adjacent opposite sides of the machine, a pair of constantly tensioned pull springs anchored at their rear ends to th side arms of the actuator and at their front ends to the lower ends of said rock arms, a rearwardly extending rock arm fixed on said rock shaft, a roll journaled on the rear end of said rearwardly extending rock arm to rotate about an axis parallel to that of said shaft, a conversely rotative shaft journaled on the framework and extending horizontally transversely of the machine above said roll, a plate cam fixed on said conversely rotative shaft and having an eccentric peripheral edge provided with spaced notches engageable by said roll, a handle fixed on said conversely rotative shaft for rotating the shaft and cam, a pair of spaced projections on said cam engageable with said roll to limit rotation of the cam in both directions, a series of type carriers, type keys, individual spring returned driving means for the type carriers each settable by depression of a different one of the type keys for actuation by the actuator when the latter is pulled forward by said pull springs to cause a printing stroke of a selected type carrier, a fore and aft extending pitman connected at its forward end to the actuator, a crank shaft journaled on the framework to rotate about a horizontal axis extending transversely of the machine and having the rear end of the pitman connected to the wrist thereof, latch means normally holding said crank shaft with with the catuator retracted and controlled by the setting action of either of said spring returned driving means to release the crank shaft for rotation through a single revolution only whether or not said key is released, and automatic power means for retracting the actuator to latched position through the medium of said crank shaft and pitman.

6. A typewriting machine, as claimed in claim 5, wherein the pitman comprises two threaded sections, a turnbuckle connecting said sections for adjustment of the length of the pitman, and a pair of turnbucklelocking nuts threaded on the respective pitman sections against opposite ends of the turnbuckle.

7. In a typewriting machine, type carriers, a rockably mounted actuator for the type carriers, operating trains connected to the respective type carriers and each including a coupler settable for actuation by the actuator to impart a printed stroke to its connected type carrier, spring means for moving the actuator in a direction to impart a printing stroke to a type carrier, a crank, a. pitman connected to the crank and actuator for limiting the working stroke of the actuator and retracting the actuator, said pitman including means for adjusting the effective length thereof, latch means for locking the crank in a position to hold the actuator retracted, a rockably mounted and spring-retracted release bar adjacent the actuator operable by setting movement of any coupler to release said latch means for a single revolution of the crank, a return stop for the release bar, a link connection between said release bar and latch means including provision for varyq 2,sss,eos ing the eiiective length of said link connection,

and power means for automatically and positive- 1y driving said crank during a portion 01' each I revolution to retract the actuator.

the combination 0! a belicrank rockable about an axis parallel to that of the actuator, a constantly tensioned pull spring connected at its ends to said actuator and to one arm 01! the bellcrank to exert a type bar driving eifort on the actuator, a roller journaled on the other arm of said bellcrank, a cam rockable about an axis parallel to that of the bellcrank and located substantially in the vertical plane of the roller, and a handle for conversely rotating the cam, said cam having an eccentric peripheral edge portion provided with a series 0! notches in which said roller is selectively seatable and also being formed with projections at the ends or said edge portion engageable with the roller to limit rotation of the cam.

mm? A. AVERY. cams wanna.

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