US3633723A

US3633723A - Power-operated typewriter

Info

Publication number: US3633723A
Application number: US11982A
Authority: US
Inventors: Paul Louis Marie Kosters
Original assignee: Sperry Rand Corp
Current assignee: Sperry Corp
Priority date: 1969-02-24
Filing date: 1970-02-17
Publication date: 1972-01-11
Anticipated expiration: 1989-01-11
Also published as: DE2009310A1; BR7016933D0; FR2032359A1

Abstract

A power-operated typewriter in which a key action mechanism cooperates with a power-operated mechanism to transmit type key depression into power-actuated movement of a respective typebar. The key action mechanism comprises an integrally formed, flexible, parallelogram-shaped structure of which a portion of the key lever forms one side and a portion of the actuating lever forms another side. A support lever, fixed to the typewriter frame, and a fourth lever form the other two sides. All the levers are connected by relatively more flexible joints and the lengths of the levers are chosen so that key depression translates into upward movement of the actuating lever. A cam lever has an arm in contact with an extension of the actuating lever and upward movement of the actuating lever causes the cam lever to rotate about a first pivot to bring its gripping surface into contact with the power roll. A bellcrank lever connected to the cam lever at the first pivot point is caused to rotate about a second pivot and actuate the typebar. During power actuation the distance between the point on the power roll contacted by the cam lever''s gripping surface increases. After completion of the upward cycle of the actuating lever it is deflected from contact with the cam lever to prevent repeat action.

Description

United States Patent 72] inventor Paul Louis Marie Kosters St. Oedenrode, Netherlands [21] Appl. No. 11,982

[22] Filed Feb. 17, 1970 [45] Patented Jan. 11, 1972 [73] Assignee Sperry Rand Corporation New York, NY.

[32] Priority Feb. 24, 1969 [33] Netherlands [54] POWER-OPERATED TYPEWRITER 15 Claims, 6 Drawing Figs.

[52] US. Cl 197/17, 197/98 [51] Int. Cl B41j 23/08 [50] Field of Search 197/17, 98; 235/145, 146

[56] References Cited UNITED STATES PATENTS 2,971,625 2/1961 Rix 197/17 2,889,024 6/1959 Toeppen 197/17 3,353,647 11/1967 Hugel l97/98X 3,393,786 7/1968 Heidt 197/17 3,393,787 7/1968 Dodge et al 197/17 Primary Examiner-Ernest T. Wright, Jr.

Assistant ExaminerR. T. Rader Att0rneys-H. Walter Clum, Marshall M. Truex and Thomas P. Murphy ABSTRACT: A power-operated typewriter in which a key action mechanism cooperates with a power-operated mechanism to transmit type key depression into power-actuated movement of a respective typebar. The key action mechanism comprises an integrally formed, flexible, parallelogram-shaped structure of which a portion of the key lever forms one side and a portion of the actuating lever forms another side. A support lever, fixed to the typewriter frame, and a fourth lever form the other two sides. All the levers are connected by relatively more flexible joints and the lengths of the levers are chosen so that key depression translates into upward movement of the actuating lever. A cam lever has an arm in contact with an extension of the actuating lever and upward movement of the actuating lever causes the cam lever to rotate about a first pivot to bring its gripping surface into contact with the power roll. A bellcrank lever connected to the cam lever at the first pivot point is caused to rotate about a second pivot and actuate the typebar. During power actuation the distance between the point on the power roll contacted by the cam levers gripping surface increases. After completion of the upward cycle of the actuating lever it is deflected from contact with the cam lever to prevent repeat action.

PATENTEB Jun 1 I972 SHEET 3 BF 4 POWER-OPERATED TYPEWRITER The invention relates to a power-operated typewriter with a continuously rotating power roll, a coupling device for each typebar, for temporarily coupling the power roll with this typebar at depression of the corresponding key, a key action mechanism for each typebar, transferring the movement of the key to the corresponding coupling device and each comprising of a key lever and an actuating lever of which one end being pivotally connected with the key lever and the other free end being adapted to move and to cooperate with the corresponding coupling device at depression of the key.

Such a typewriter is commonly known, whereby the key action mechanism as well as the coupling device each comprises a great number of levers and hinges. It will be clear, that in this way the typewriter is complicated and expensive and is sensitive for disturbances.

The invention aims to improve the known power-operated typewriter and this improvement is in the first place obtained in that said key action mechanism of each typebar is formed as a flat unit from one piece of material, whereby the joint between one end of the actuating lever and the key lever is formed by means of a more elastic portion of the unit, further consisting of a support lever connected unmovably with a crosspiece of the typewriter frame and connected with a point of the actuating lever intermediate of both ends by means of another more elastic portion of the unit, and a fourth lever which is arranged between the support member and the key lever through joints formed by means of more elastic portions of the unit, whereby the lengths of the four levers between the joints and their relative positions, are such that at depression of the key on the key lever, this key lever is caused to carry out only a translational movement in its own plane with respect to the frame of the typewriter.

Each key action mechanism comprises a parallelogramshaped structure, whereby the part of the key lever and the part of the support lever between their two joints form the vertical pair of opposite sides of the parallelogram and the part of the actuating lever and the part of the fourth lever between their two joints form the horizontal pair of opposite sides of the parallelogram. In this way a key mechanism is obtained consisting on one piece of material, by which it can be manufactured cheaper, while the force with which a key lever is depressed is independent of the place where the key is fixed to the key lever. This last advantage is the result of the parallelogram-shaped structure of the key action mechanism. Also in normal cases for each typebar a separate key action mechanism is used, according to the invention it is also possible to combine all key action mechanisms to one block, made of one piece of material. Such a block simplifies the production and the assembling, but presents a drawback if one of the mechanisms is damaged, since in that case the whole block must be replaced by a new one.

According to the invention the coupling device of each typebar comprises a cam lever having an arm cooperating with the free end of the actuating lever of the key mechanism and a surface for gripping said power roll, whenever its arm is moved upwardly by the free end of the actuating lever, whereby the arm of the cam lever is pivotally connected with a bellcrank lever, one end of which being pivotally connected with the frame of the typewriter and the other end being connected with the typebar through a link, while the cam lever and the bellcrank lever having cooperating faces which are pressed against each other by spring means in the unactuated position of the coupling device. The cam surface of the cam lever is so formed, that the distance between the pivot on the bellcrank lever and the points of the cam surface which are subsequently gripped by the power roll increases continuously. In this way a powerful driving of the typebar is obtained with only a small movement in upward direction of the free end of the actuating lever of the key action mechanism.

On the bellcrank lever at the side of the cam lever another cam surface is provided for forcing the free end of the actuating lever laterally, if the bellcrank lever is in the position wherein the free end of the typebar is lying against the platen of the typewriter, so that the cam lever can return to its rest position, even if the key lever is still depressed.

In this way it is prevented, that when the key remains depressed, the typebar will be pressed again against the platen.

The application will be declared now with reference to the drawings, in which a number of embodiments of the invention are shown:

FIG. I is a vertical cross section of a typewriter with one of the key action mechanisms, whereby with full lines the coupling device and the typebar are shown in rest position, and with dot-and-dashed lines in the active end position;

FIG. 2 shows a cross section corresponding with FIG. 1 with the key action mechanism and coupling device with typebar in an intermediate position;

FIG. 3 shows a side view of a key action mechanism with full lines in the rest position and with dot-and-dashed lines in the completely depressed active position;

FIG. 4 shows a second embodiment of the key action mechanism in the rest position;

FIG. 5 shows a third embodiment of the key action mechanism in the rest position;

FIG. 6 shows a perspective view of a key action mechanism block, forming a combination of all key action mechanisms of all typebars of the typewriter, whereby each key action mechanism is formed according to the first embodiment.

In FIG. 1 the typewriter is indicated with 10, the key action mechanism with 11 and the coupling device with 12. It will be clear that for each typebar and thus generally for each pair of letters or symbols of the typewriter one key action mechanism 1 1 and one coupling device 12 is present.

The key action mechanism 11 of each typebar is a unitary structure formed or molded in one piece and may be made of a flexible, resilient material, such as plastic, hard rubber etc.

The key action mechanism comprises a key lever 13, provided with a lug 14, on which a key 15 is fixed. It should be noted, that the key lever 13 may be of any desired length, with the lug 14 and the key 15 disposed at the end of the key lever. This makes it possible to accommodate generally 44 key action mechanisms in the available space. Regardless of the length of the key lever 13 or the position of the lug and typekey, the necessary actuating pressure remains essentially unvaried. This occurs as a result of the form of the key action mechanism according to the invention, which form will be described hereafter.

The key lever 13 is provided with a vertical downwardly extending part 16, which transfers the movement to an actuating lever 17, which is connected to the vertical part 16 by means of a flexible connection 18, formed by a more flexible part of the mechanism.

A support member 19 is rigidly mounted on a crosspiece 20 (shown in section), which in turn is secured between the sideframes of the typewriter 10. Generally 44 key action mechanisms 11 would be mounted on the crosspiece 20.

The lower portion of the support member 19 is connected with the approximate midpoint at the bend of the actuating lever 17 via a flexible connection 21, formed by a more flexible part of the mechanism. The support member 19 is also connected to the upper part of the vertical part 16 via

flexible connections

22 and 23, disposed at each end of the fourth lever 24. The more flexible parts, forming the hinge connections, are formed by thinner parts of the mechanism, as clearly appears from FIG. 1. From this FIG. it is also clear, that the

hinges

18 and 21 are loaded substantially only on tension, when the key 15 is depressed.

The vertical part 16 of the key lever 13 has a recess 25. A lip 26 disposed at the end of an extension of the support member 19 extends into the recess 25 and is provided with two forkarms 26a, enclosing partly the vertical part 16 to prevent sidelong displacement of the part 16 with respect to the extension 26. The lip 26 and the recess 25 serve as a top and bottom limit stop for the key action mechanism. In FIG. 1 the key action mechanism is in the rest position and the lower side of the lip 26 engages the lower side of the recess 25. When the key is depressed, the upper side of the lip 26 engages the upper side of the recess 25. An intermediate position of the key action mechanism is shown in FIG. 2, in which position none of both stops are in action.

It will be clear from FIGS. 1 and 2, that the key action mechanism will move as a parallelogram, of which the vertical part 16 of the key lever 13 and the vertical part of the support member 19 form one pair of sides, while the lever 24 and the part of the actuating lever 17 between the

hinges

18 and 21 form the other pair of sides. It will be also clear that at depression of the key 15 the key lever 13 moves in downwards direction, but remains parallel to itself. This means that also the pressure, which is necessary to depress the key 15 is independent from the distance between the key 15 and the vertical part 16 of the key lever 13. In FIG. 1 three other keys are shown, which are connected with separate key levers 13, disposed behind the key lever 13 shown in FIG. 1.

If the key 15 is depressed the free end 27 of the actuating lever 17 will move upwards, as appears from FIG. 2 in which, however, the end position of the free end 27 has not yet been reached. The key action mechanism in the undepressed rest position and in the completely depressed pressed active position is shown in FIG. 3, in which last mentioned position is shown with dot-and-dashed lines.

The lifting of the free end 27 for a rather short distance is sufficient to actuate the coupling device 12.

' Each key action mechanism 11 has associated therewith a typebar 29, as shown in FIG. 1. The typebar 29 is pivoted about a shaft 30, mounted in the frame of the typewriter 10. In its unactuated rest position as shown in FIG. 1 in full lines, the typebar 29 rests against a typebar stop 31. In its fully actuated position, as shown in dot-and-dashed lines in FIG. 1, the typebar 29 is in impact position against platen 32.

The coupling device 12, which at depression of the key action mechanism 1 1 drives the typebar 29 against the platen 32, comprises the power roll 28, which is continuously driven, cam lever 33 and a bellcrank lever 34. One end of the bellcrank lever 34 is connected to a lobe 29a of the typebar 29 via a link 35. The other end of the bellcrank lever 34 is pivoted on a shaft 36, which is supported in the frame of the typewriter 10. The cam lever 33 is pivotally mounted on the bellcrank lever 34 by a pin 37. A spring 38 biases the cam lever 33 and the bellcrank lever 34 against each other in the unactuated rest position of the coupling device. A lip 34a on the bellcrank lever 34 acts as a stop for the cam lever 33.

The free end 27 of the actuating lever 17 is disposed just under an extension 33a of the cam lever 33.

The cam surface 33b in its unactuated rest position sits slightly away from touching contact with the power roll 28, FIG. 1. A little force however is sufficient to rotate the cam lever 33 a sufficient distance about the pin 37 to cause cam surface 33b to be gripped by the clockwise rotating power roll 28. Depression of typekey 15 causes the free end 27 to rotate the cam lever 33 the necessary distance.

When the cam surface 33b is gripped by the power roll 28, the cam surface 33b is rapidly moved a short distance along the surface of the power roll. The rapid change of the distance between the pivot pin 37 and the point of contact between the cam surface 33b and the power roll 28 causes a rapid movement of the bellcrank lever 34 about the shaft 36. The bellcrank lever 34 via link 35 causes the typebar 29 to rotate about the shaft 30 and the end of the typebar impact against the platen 32 (shown in dot-and-dash lines in FIG. 1

After the bellcrank lever 34 and therefore the typebar 29 are set in motion, the cam surface 33b breaks contact with'the power roll 28. The spring 38 then returns the cam lever 33 to rest against the stop 34a and the cam lever 33 and the bellcrank lever 34 return to their unactuated position. If the key 15 is still depressed at this moment, the free end 27 is still in the raised position and the cam lever 33 cannot return to its rest position, since the extension 33a pushes against the free end 27. The cam surface 33b is then again gripped by the power roll 28 and the typebar 29 is pushed again against the platen 32. This will continue as long as the key 15 is depressed. If the key 15 is released, the free end 27 can return to its rest position.

While this repeat action is generally not desired, it is desired when a number of the same symbols subsequently must be printed, for instance if a word is underlined. In order to prevent this repeat action at the coupling devices of the suitable typebars, a further cam surface 40 is provided on that part of the bellcrank lever 34, which in the utmost position, in FIG. 1 shown with dot-and-dash lines, is behind the free end 27 of the actuating lever 17. By this cam surface 40 the free end 27 will be bent away transversely perpendicular to the plane of the drawing in the forward direction, by which this free end 27 no longer lies in the path of movement of the extension 3311 of the cam lever 33, so that this extension 33a can move downwardly under influence of the tension spring 38, which pulls again the cam lever 33 and the bellcrank lever 34 against each other. In this way it is possible that the cam lever 33 returns to its rest position. Even if the free end 27 is still in its highest position as a result of the depression of the key 15. The cam surface 40 is thus present at that side of the bellcrank lever 34, which is directed to the cam lever 33. The end of the cam surface 40 directed to the right forms an inclining ramp surface.

In order to permit bending of the free end 27 in the sideward direction in the actuating lever 17 between the joint 21 and the free end 27 a thinner part 41 is present, by which the part of the actuating lever 17 beyond the joint 41 has a certain flexibility in the direction transverse to the plane of the drawmg.

Generally in a typewriter 44 key action mechanisms 11 and 44 coupling devices 12 are present, each belonging to one typebar 29. A normal shift mechanism (not shown) is used to provide each key 15 and each typebar 29 with two symbols, so that one or the other could be selected to be printed.

While the

flexible joints

18, 21, 22 and 23 provide provision resiliently to return the associated key action mechanism 1 I to its normal undepressed position, a more positive and controllable action can be obtained by the use of a coil spring 42, leaf spring or the like, fixed between a point of the vertical part 16 of the key lever 13 and the frame of the typewriter 10. This spring 42 can be disposed in such a way, that the line of action of the spring is horizontal in the middle position of the key action mechanism, see FIG. 2, in which horizontal position the spring is biased. This means that at depression of a key from the rest position the spring 42 is first compressed, thus resisting the movement of the key, until the dead middle position is reached, in which the spring acts neither in the upward, nor in the downward direction. At further depression of the key 15 the spring passes its dead position and acts in the downward direction, until the bottom stop is reached. The pretension of the spring can be made adjustably with normal means, whereby preferably all springs of all key action mechanisms are adjusted at the same time. It is also possible to adjust the level of the dead middle position with simple means.

In the FIGS. 1, 2 and 3 one embodiment of the key action mechanism 11 is shown, with a certain embodiment of the stops, which limit the movements of the key action mechanism. FIG. 4 shows another embodiment of the key action mechanism 11 according to the invention, that in principle corresponds to the first embodiment, but whereby the extension 26 according to the first embodiment is now present on the actuating lever 17 and is indicated with 26', while the recess 25, in the first embodiment arranged in the vertical part 16 of the key lever 13, is now arranged on the support member 19 and is indicated with 25'.

At the embodiment according to FIG. 5 the stops are arranged at the frame of the typewriter and for instance they can be formed by a U-shaped member indicated with 25", whereby the extension 26 is now replaced by an extension 26", arranged on the vertical part 16 of the key lever 13.

In FIG. 6 in perspective view a key action mechanism block 43 is shown, that combines all key action mechanisms for all typebars. The mechanisms themselves are for instance carried out according to the first embodiment. Such a block permits a simple assembling, but has as disadvantage that at fracture of one of the levers the whole block must be replaced, while when for each typebar a separate key action mechanism is applied, this can be replaced individually. It is also possible to divide the block into a small number of smaller blocks.

I claim:

1. A power-operated typewriter of the type having a motordriven power roll for translating manual key depression into powered movement of associated typebars, comprising in combination:

a plurality of cam means,

each of said cam means coupling the power roll to one typebar when its associated key is depressed,

a plurality of key action mechanisms,

each of said key action mechanisms comprising,

a key lever,

an actuating lever having one end disposed in actuating relationship to a respective cam means,

flexible means formed in one piece with said key lever and said actuating lever transmitting movement from said key lever to said actuating lever for actuating the respective cam means whereby a selected typebar is actuated.

2. A power-operated typewriter according to claim 1 wherein said flexible means further comprises,

a support lever rigidly connected to the frame of the typewriter,

a fourth lever,

a vertical portion of said key lever, a portion of said actuating lever said support lever and said fourth lever forming the four sides of a parallelogram-shaped structure.

3. A power-operated typewriter according to claim 2 wherein said key lever, said actuating lever, said support lever and said fourth lever are interconnected by joint means having smaller thicknesses than other portions of said flexible means making them relatively more flexible than other portions of said flexible means.

4. A power-operated typewriter according to claim 3 wherein,

said actuating lever has the other end connected to the lower end of the vertical portion of said key lever and a point intermediate its ends connected to one end of said support lever,

said fourth lever has one end connected to the other end of said support lever and its other end connected to the key lever,

said vertical portion of said key lever and said support lever forming a pair of opposite sides of said parallelogramshaped structure with said portion of said actuating lever and said fourth lever forming the other pair of opposite sides.

5. A power-operated typewriter according to claim 4 further comprising,

spring means connected between said key action mechanism and the frame of said typewriter for exerting a return bias on said key action mechanism when said key action mechanism is out of its normally unactuated position.

6. A power-operated typewriter according to claim 4 further comprising,

stop means disposed on said key lever and on an extension of said support lever for limiting movement of said key lever between top and bottom extreme positions.

7. A power-operated typewriter according to claim 6 wherein said stop means comprises,

a recess formed in the key lever, said recess having opposing sidewalls,

a projection on said extension extending into said recess whereby said top and bottom extreme positions are defined by the sidewalls of said recess.

8. A power-operated typewriter according to claim 7 further comprising,

9. A power-operated typewriter according to claim 4 wherein each of said cam means comprises,

a cam lever having an arm in contiguous relationship with said one end of said actuating lever and a surface for gripping the power roll when said actuating lever is moved by depression of its associated key lever,

means for deflecting said actuating lever from contact with said arm when said cam lever has completed its movement.

10. A power-operated typewriter according to claim 9 wherein said cam means further comprises,

a bellcrank lever having one end pivotally connected to the frame of the typewriter and the other end connected to the typebar,

pivot means pivotally connecting said bellcrank lever and said arm of said cam lever,

spring means connected between said cam lever and said bellcrank lever normally biasing them together in the unactuated position,

said cam surface being so formed that the distance between said pivot means and the point of contact between the power roll and said cam surface increases during rotation of said bellcrank lever about its pivot,

said means for deflecting said actuating lever comprising a cam surface disposed on said bellcrank lever,

whereby depression of the associated key lever causes powered actuation of the typebar without repeat action even if the key lever is maintained depressed.

11. A power-operated typewriter according to claim 8 wherein each of said cam means comprises,

12. A power-operated typewriter according to claim 11 wherein said cam means further comprises,

13. in a transmission system for use in a power-operated typewriter,

a plurality of key action mechanisms,

each of said key action mechanisms comprising a key lever,

an actuator member,

first means including said key lever and said actuator member formed in one piece fixed to the typewriter frame and flexibly interconnecting said key lever and said actuator member for transmitting movement from said key lever to said actuator member,

power action means comprising,

said first means comprises,

a parallelogram-shaped structure,

a vertical member and a support member forming a pair of opposite sides of said parallelogram-shaped structure with a horizontal member and said actuator member forming the other pair of opposite sides of said parallelogram shaped structure,

flexible connectors interconnecting said key lever, said actuator member, said support member and said horizontal member,

means fixing said support member to the typewriter frame,

said key lever being an extension of said vertical member.

it i t I! i

Claims

1. A power-operated typewriter of the type having a motor-driven power roll for translating manual key depression into powered movement of associated typebars, comprising in combination: a plurality of cam means, each of said cam means coupling the power roll to one typebar when its associated key is depressed, a plurality of key action mechanisms, each of said key action mechanisms comprising, a key lever, an actuating lever having one end disposed in actuating relationship to a respective cam means, flexible means formed in one piece with said key lever and said actuating lever transmitting movement from said key lever to said actuating lever for actuating the respective cam means whereby a selected typebar is actuated.

2. A power-operated typewriter according to claim 1 wherein said flexible means further comprises, a support lever rigidly connected to the frame of the typewriter, a fourth lever, a vertical portion of said key lever, a portion of said actuating lever said support lever and said fourth lever forming the four sides of a parallelogram-shaped structure.

4. A power-operated typewriter according to claim 3 wherein, said actuating lever has the other end connected to the lower end of the vertical portion of said key lever and a point intermediate its ends connected to one end of said support lever, said fourth lever has one end connected to the other end of said support lever and its other end connected to the key lever, said vertical portion of said key lever and said support lever forming a pair of opposite sides of said parallelogram-shaped structure with said portion of said actuating lever and said fourth lever forming the other pair of opposite sides.

5. A power-operated typewriter according to claim 4 further comprising, spring means connected between said key action mechanism and the frame of said typewriter for exerting a return bias on said key action mechanism when said key action mechanism is out of its normally unactuated position.

6. A power-operated typewriter according to claim 4 further comprising, stop means disposed on said key lever and on an extension of said support lever for limiting movement of said key lever between top and bottom extreme positions.

7. A power-operated typewriter according to claim 6 wherein said stop means comprises, a recess formed in the key lever, said recess having opposing sidewalls, a projection on said extension extending into said recess whereby said top and bottom extreme positions are defined by the sidewalls of said recess.

8. A power-operated typewriter according to claim 7 further comprising, spring means connected between said key action mechanism and the frame of said typewriter for exerting a return bias on said key action mechanism when said key action mechanism is out of its normally unactuated position.

9. A power-operated typewriter according to claim 4 wherein each of said cam means comprises, a cam lever having an arm in contiguous relationship with said one end of said actuating lever and a surface for gripping the power roll when said actuating lever is moved by depression of its associated key lever, means for deflecting said actuating lever from contact with said arm when said cam lever has completed its movement.

10. A power-operated typewriter according to claim 9 wherein said cam means further comprises, a bellcrank lever having one end pivotally connected to the frame of the typewriter and the other end connected to the typebar, pivot means pivotally connecting said bellcrank lever and said arm of said cam lever, spring means connected between said cam lever and said bellcrank lever normally biasing them together in the unactuated position, said cam surface being so formed that the distance between said pivot means and the point of contact between the power roll and said cam surface increases during rotation of said bellcrank lever about its pivot, said means for deflecting said actuating lever comprising a cam surface disposed on said bellcrank lever, Whereby depression of the associated key lever causes powered actuation of the typebar without repeat action even if the key lever is maintained depressed.

11. A power-operated typewriter according to claim 8 wherein each of said cam means comprises, a cam lever having an arm in contiguous relationship with said one end of said actuating lever and a surface for gripping the power roll when said actuating lever is moved by depression of its associated key lever, means for deflecting said actuating lever from contact with said arm when said cam lever has completed its movement.

12. A power-operated typewriter according to claim 11 wherein said cam means further comprises, a bellcrank lever having one end pivotally connected to the frame of the typewriter and the other end connected to the typebar, pivot means pivotally connecting said bellcrank lever and said arm of said cam lever, spring means connected between said cam lever and said bellcrank lever normally biasing them together in the unactuated position, said cam surface being so formed that the distance between said pivot means and the point of contact between the power roll and said cam surface increases during rotation of said bellcrank lever about its pivot, said means for deflecting said actuating lever comprising a cam surface disposed on said bellcrank lever, whereby depression of the associated key lever causes powered actuation of the typebar without repeat action even if the key lever is maintained depressed.

13. In a transmission system for use in a power-operated typewriter, a plurality of key action mechanisms, each of said key action mechanisms comprising a key lever, an actuator member, first means including said key lever and said actuator member formed in one piece fixed to the typewriter frame and flexibly interconnecting said key lever and said actuator member for transmitting movement from said key lever to said actuator member, power action means comprising, a continuously rotatable power roll, a typebar for each key action mechanism, trigger means responsive to movement of said actuator member to couple a respective typebar to said power roll for actuation of said typebar.

14. In a transmission system according to claim 13 wherein said first means comprises, a support member fixed to said typewriter frame, and flexible connector means interconnecting said support member, and said actuator member so that said actuator member moves in response to movement of said key lever.

15. In a transmission system according to claim 13 wherein said first means comprises, a parallelogram-shaped structure, a vertical member and a support member forming a pair of opposite sides of said parallelogram-shaped structure with a horizontal member and said actuator member forming the other pair of opposite sides of said parallelogram shaped structure, flexible connectors interconnecting said key lever, said actuator member, said support member and said horizontal member, means fixing said support member to the typewriter frame, said key lever being an extension of said vertical member.